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SERVICE MANUAL
CODE: 00ZAR5132TM1E
DIGITAL COPIER NO.2
MODEL
AR-5132
CONTENTS
[ 1 ] PRINCIPLES OF THE DIGITAL COPIER . . . . . . . . . . . . . . . . . . . 1-1 [ 2 ] PROCESS SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 [ 3 ] DEVELOPING SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 [ 4 ] PAPER FEED SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 [ 5 ] TRANSPORT AND FUSING SECTION . . . . . . . . . . . . . . . . . . . . 5-1 [ 6 ] HIGH VOLTAGE SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 [ 7 ] RADF MECHANISM SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 [ 8 ] DESK UNIT MECHANISM SECTION . . . . . . . . . . . . . . . . . . . . . . 8-1 [ 9 ] ELECTRICAL SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1 [10] RADF ELECTRICAL SECTION . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 [11] DESK UNIT ELECTRICAL SECTION . . . . . . . . . . . . . . . . . . . . . 11-1
Parts marked with "!" is important for maintaining the safety of the set. Be sure to replace these parts with specified ones for maintaining the safety and performance of the set.
This document has been published to be used for after sales service only. The contents are subject to change without notice.
SHARP CORPORATION
CAUTION This copier machine is a class 1 laser product that complies with 21CFR 1040.10 and 1040.11 of the CDRH standard and IEC825. This means that this machine does not produce hazardous laser radiation. The use of controls, adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure. This laser radiation is not a danger to the skin, but when an exact focusing of the laser beam is achieved on the eye's retina, there is the danger of spot damage to the retina. The following cautions must be observed to avoid exposure of the laser beam to your eyes at the time of servicing. 1) When a problem in the laser optical unit has occurred, the whole optical unit must be exchanged as a unit, not as individual parts. 2) Do not look into the machine with the main switch turned on after removing the developer unit, toner cartridge, and drum cartridge. 3) Do not look into the laser beam exposure slit of the laser optical unit with the connector connected when removing and installing the optical system. 4) The safety interlock switch is equipped. Do not defeat the safety interlock by inserting wedges or other items into the switch slot.
CAUTION CLASS 1 LASER PRODUCT
INVISIBLE LASER RADIATION, WHEN OPEN AND INTERLOCKS DEFEATED. AVOID EXPOSURE TO BEAM.
VARO !
AVATTAESSA JA SUOJALUKITUS OHITETTAESSA OLET ALTTIINA NÄKYMÄTTÖMÄLLE LASERSÄTEILYLLE ÄLÄ KATSO SÄTEESEEN.
VORSICHT LASER KLASSE 1
UNSICHTBARE LASERSTRAHLUNG, WENN ABDECKUNG GEÖFFNET UND SICHERHEITSVERRIEGELUNG ÜBERBRÜCKT. NICHT DEM STRAHL AUSSETZEN.
ADVARSEL
USYNLIG LASERSTRÅLNING VED ÅBNING, NÅR SIKKERHEDSBRYDERE ER UDE AF FUNKTION. UNDGÅ UDSAETTELSE FOR STRÅLNING.
VARNING !
LASER WAVE LENGTH : 785 ± 15nm Pulse times : Out put power : 0.3mW 0.6mW OSYNLIG LASERSTRÅLNING NÄR DENNA DEL ÄR ÖPPNAD OCH SPÄRREN ÄR URKOPPLAD. BETRAKTA EJ STRÅLEN. STRÅLEN ÄR FARLIG.
CONTENTS
[ 1 ] PRINCIPLES OF THE DIGITAL COPIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1. Difference in structure from analog copiers 1-1 2. Basic composition of the digital copier . . . . 1-1 3. Scanner section . . . . . . . . . . . . . . . . . . . . 1-2 . . . . . . . . . . . . . . . 1-4 4. Laser unit . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 5. Image process section
[ 7 ] RADF MECHANISM SECTIONS . . . . 7-1
1. Operation flowchart . . . . . . . . . . . . . . . . . . 7-1 2. Document size detection . . . . . . . . . . . . . . 7-4
[ 8 ] DESK UNIT MECHANISM SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
1. Operation flow chart . . . . . . . . . . . . . . . . . . 8-1
[ 2 ] PROCESS SECTION . . . . . . . . . . . . . . . 2-1
1. Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2. Basic process and composition . . . . . . . . . 2-3
[ 9 ] ELECTRICAL SECTION . . . . . . . . . . . . 9-1
1. Block diagram . . . . . . . . . . . . . . . . . . . . . . 9-1 2. ICU PWB . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2 3. PCU PWB . . . . . . . . . . . . . . . . . . . . . . . . . 9-6 4. Operation section . . . . . . . . . . . . . . . . . . . 9-16 5. LCD display section . . . . . . . . . . . . . . . . 9-17 6. DC power circuit . . . . . . . . . . . . . . . . . . . . 9-22
[ 3 ] DEVELOPING SECTION . . . . . . . . . . . . 3-1
1. Basic outline . . . . . . . . . . . . . . . . . . . . . . . . 3-1 2. Basic composition . . . . . . . . . . . . . . . . . . . 3-1 3. Basic operation . . . . . . . . . . . . . . . . . . . . . 3-1
[10] RADF ELECTRICAL SECTION . . . . 10-1
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 2. Block diagram . . . . . . . . . . . . . . . . . . . . . 10-1 3. Operations . . . . . . . . . . . . . . . . . . . . . . . . 10-2
[ 4 ] PAPER FEED SECTION . . . . . . . . . . . . 4-1
1. Basic outline . . . . . . . . . . . . . . . . . . . . . . . . 4-1 2. Basic composition . . . . . . . . . . . . . . . . . . . 4-1 3. Basic operation . . . . . . . . . . . . . . . . . . . . . 4-2
[ 5 ] TRANSPORT AND FUSING SECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
1. Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 2. Basic composition and functions . . . . . . . . 5-1
[11] DESK UNIT ELECTRICAL SECTION . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
1. Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1 2. Block diagram . . . . . . . . . . . . . . . . . . . . . 11-1 3. Operational descriptions . . . . . . . . . . . . . 11-2
[ 6 ] HIGH VOLTAGE SECTION . . . . . . . . . 5-1
1. Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 2. Basic composition . . . . . . . . . . . . . . . . . . . 5-1
[1] PRINCIPLES OF THE DIGITAL COPIER
1. Difference in structure from analog copiers
Analog machine
Copy lamp section
Digital machine
Copy lamp section
Scanner
CCD
Laser section Drum
section
Printer section
Drum
The digital copier is composed of the scanner section and the printer section. (Refer to the figures.) In the digital copier, the reflected light is not directly radiated onto the OPC drum as in the analog copiers.
2. Basic composition of the digital copier
OPU (Operation panel section) RADF
Serial communication
Scanner section Serial communication
CCD
Option Lens Printer PWB
ICU (Image process unit) PCU (Process Control Unit) Serial communication LSU (Laser unit)
Interface PWB
Laser beam Serial communication Process section
Personal computer
Manual paper feed section
Fusing section Paper transport section Sorter (Option) ADU
ADU
Paper tray 1 Paper tray 2
Paper feed section
Paper tray 3 (LCC type)
11
(1) Basic operations of copying
1 Image data are scanned in the scanner section and sent to the
image process (ICU) PWB. 2 The data are converted into printable data in the circuit of the image process (ICU) PWB. 3 The data are printed in the printer section.
(2) Basic structure of the scanner section
The scanner unit is the scanning section of the digital optical system. The light from the halogen lamp (which is driven by the DC power to suppress ripples) is reflected by the document and passed through three mirrors and the reduction lens to form images on the CCD elements (image sensors). This system is called the reduction type image sensor system. The light image (photo energy) formed on the CCD elements are converted into electrical signals (analog signals) by the CCD elements (Photo conversion).The output signals (analog signals) are converted into digital signals (A/D conversion) to perform various image processes. The resolution at that time is 400dpi.
3. Scanner section
(1) How to scan an document
The scanner is provided with sensors which are arranged on one line. These sensors scan a horizontal line of an document at a time and the data are outputted sequentially. After completion of the line, the next line is scanned. The operation is repeated until one page is completed. The figure below shows that the images scanned by the sensors are sent to the ICU PWB sequentially.
Sub scanning direction Sensor scanning area Main scanning direction
4. Laser unit
The image data sent from the ICU (image process PWB) are passed to the LSU (laser unit) and converted into laser beams.
(1) Basic structure
The LSU unit is the writing section of the digital optical system. The semiconductor laser is used as the light source. Images are formed by the polygon mirror and the f lens on the OPC drum. The internal structure is shown in the figure on the next page. The image data from the ICU are converted into DUTY signals for every gradations (256 steps), and the semiconductor laser on the laser emitting PWB is turned on/off according to the DUTY. The laser beams are passed through the collimator lens, the slit, the cylindrical lens, the polygon mirror, the f lens, and the mirror to form images in the shaft direction (main scanning direction) of the OPC drum. The laser emitting PWB is provided with the APC (Auto Power Control) to eliminate fluctuations in the laser power. The BD PWB serves to measure the writing point for the laser.
1 2 3
Original
(2) Composition
Effective scanning width: 302 mm Resolution: Beam diameter: Image surface power: 400 dpi main scanning 75 µm, sub scanning 90 µm 0.3mW 0.6mW Brushless DC motor No. of mirrors 6
4
5
Polygon motor:
Image data sent to the ICU PWB
5 4 3 2 1
To ICU PWB
The direction of the lines is called the "main scanning direction" and the direction of scanning the "sub scanning direction." The above figure shows four elements in one line. Actually, however, there are thousands of elements in one line. The light receiving elements called CCD are used. The resolution is an index value to express the capacity of scanners. The resolution shows how many light receiving elements are used in one inch (dpi, dot per inch). While the sub scanning direction is used to control the motor which drives the optical system and to adjust the resolution to take in the images.
12
LSU internal structure
abc
d= e=f
f lens 3 BD PWB Convergence lens for BD Mirror
a
b
c
d
e
f
Polygon motor
f lens 2 f lens 1
f LENS
Mirror for BD Polygon motor fan drive PWB
lens (Cylindrical lens)
Leser drive PWB
Functions of major parts 1 Collimator lens
Converges laser beams into parallel beams.
2 Cylindrical lens
Corrects laser beams in the sub scanning direction by shift of the surface of the polygon mirror. 3 BD (Mirror, lens, PWB)
Polygon motor
f lens 1
Side view f lens 3 Mirror
Detects the start timing of the laser scanning.
4 f lens
Equalizes the scanning speeds of laser beams at both ends and at the center. 5 Polygon mirror, polygon motor Reflects laser beams at constant rotation.
f lens 2
· ·
Converges laser beams on a spot on the OPC drum.
Cover glass
Drum
6 Semiconductor laser
Generates laser beams.
Drum L.D Collimator lens Cylindrical lens Lens
Sub scanning direction
13
5. Image process section
Data flow (flowchart) Content 1. Halogen lamp (145W) The lamp is lighted by the DC power under the reference white plate. 2. 400dpi reduction line sensor (CCD) The sensor receives the reflected light as photo energy from the shading plate (reference white plate), and converts it into electrical energy (analog voltage).
CCD PWB
Photo energy Shift electrode
1.
Halogen lamp (ON)
2.
CCD
Accumulation electrode Photo diode
3.
A/D convertor
ICU PWB
3. A/D convertor The analog voltage is divided into 256 to convert into digital data, that is, the voltage is converted into binary 8-bit data. Actually, the white data before A/D conversion is about 4.0V, and the black data is about 1.1V. Therefore, the difference between about 4.0V of white and about 1.1V of black is divided into 256 divisions to convert into digital data. (Example: 1.1V 0, 4.0V 256, 2.55V 128) 4. Gate array The digital data sent from the A/D convertor are inputted to the gate array temporarily.
4.
GA1
5. SRAM Stores the data. 6. CPU Judges with the value written into the SRAM whether the light is too bright or too dark. If the light is too bright, it decreases the halogen lamp voltage. If the light is too dark, it increases the halogen lamp voltage. Procedures 1 6 are repeated to set the light quantity at the optimum level.
5. 6.
SRAM CPU
7.
Halogen lamp
7. Halogen lamp (Black level correction) For black level correction, data obtained by SIM 63-2 are used. (The data are stored in the SRAM.) 8. CCD Though the halogen lamp is off, a constant voltage is outputted from the CCD. 9. A/D convertor The output voltage (analog voltage) is converted into a digital value. (The digital value may be ideally zero, however it will not become zero because of variations between machines.) 10. Gate array 1 The digital data sent from the A/D convertor are temporarily stored in gate array 1.
8.
CCD
CCD PWB
9.
A/D convertor
10. 11. 12.
GA1 SRAM CPU
ICU PWB
11. SRAM Stores data. 12. CPU Obtains the optimum black reference value from the black image data written into the SRAM. In the hardware, the odd number pixels and the even number pixels in the main scanning direction are treated in two separate channels. Therefore, two reference values for the odd numbers and the even numbers are required. 13. Latch The reference values of the odd numbers and the even numbers are stored in the latch. 14. D/A convertor The black reference values stored in the latch are converted into analog voltages by the D/A convertor. The analog voltages are used as the black reference values (- reference) of A/D conversion. Procedures 8 14 are repeated to obtain the optimum black reference values.
13. 14.
Latch D/A convertor
14
Data flow (flowchart)
Content 15. Halogen lamp For white level correction, the halogen lamp is lighted at the voltage obtained in the light quantity adjustment under the shading plate and the shading plate is scanned. 16. CCD The reflected light from the shading plate is received by the CCD as photo energy and converted into electrical energy (analog voltage). 17. The analog voltage is divided into 256 sections (0 255) to be digital data.
15.
Halogen lamp
16.
CCD
CCD PWB
17.
A/D convertor
18. Gate array 1 The digital data are inputted to gate array 1 and thinned out every 16 lines. 19. SRAM Stores data. Thinning out every 16 lines is performed in order to minimize the bad effect by dirt on the shading plate.
ICU PWB
18. 19. 20.
GA1 SRAM CPU
20. CPU The optimum white reference of 5048 pixels in the main scanning direction is obtained from the SRAM data. At that time, the correction of variations between odd/even numbers is performed as well as the correction of the halogen lamp and the lens. These corrections are made in order to prevent against darkness at both ends. In addition, the correction for variations between the document surface and the shading plate previously obtained by SIM 63-2 is performed. 21. FIFO The correction data of one line are stored in the line memory (FIFO). 22. D/A convertor The correction data of FIFO are converted into analog values to be the white reference value (+ reference) in 17. The white reference value is switched for every pixel.
21. 22.
FIFO
D/A convertor
23.
Halogen lamp
23. Halogen lamp The halogen lamp is lighted at the voltage obtained by procedures 1 6 to radiate the document.
CCD PWB
24.
CCD
24. CCD The scanned image data are sent to the ICU PWB with the analog signals. 25. A/D convertor, D/A convertor, latch, FIFO Procedures 1 22 are performed at the specified timings such as turning on the power. The values obtained in 1 22, however, the black reference values of odd/even numbers are stored in the latch, and the white reference value is stored in the FIFO. Therefore, shading correction is performed in copying. The white/black reference values of the A/D convertor are switched for every pixel to correct unevenness of the optical system and converted into digital values. 26. Gate array 1 Takes data of the density level of the scanned document.
25.
A/D convertor
D/A convertor Latch
FIFO GA 1
26.
Histogram
CPU
ICU PWB
Density value A
Density value B
Density value C
A judgment is made whether the document is of A type (an document of characters with much white area) or of B type (a photo document with much half tone area) or of C type (newspapers with much background area) to select the most suitable look-up table for density conversion.
27.
Density conversion LUT
27. CPU/SRAM Converts the density. For an document of A type, an LUT (look-up table) which provides clear characters is selected. For an document of B type, an LUT which provides clear half tone images is selected. For an document of C type, an LUT which removes background. Since process is performed for every several lines. the most suitable LUT may not be selected for some documents. In that case, the manual exposure mode is selected.
15
Data flow (flowchart)
Content 28. FIFO Image data of one line are stored in the line memory (FIFO). This FIFO is for zooming. For reduction, the scanned image data are thinned out when they are written into the FIFO. For enlargement, the scanned image values are used as the values of plural pixels of the next one.
28.
FIFO
29.
GA2
(Zooming)
29. Gate array 2 Gate array 2 outputs the control signal to the FIFO to perform reduction and enlargement. Interpolation is also performed, which eliminates notches generated in enlargement. Two neighboring pixels before enlargement are interpolated primarily to eliminate notches.
A
C
B
d1
: Density of pixel in normal ratio ( 0 255) Position if a pixel to be inserted. Density of the pixel which was formed by interpolation. (0 255)
D5
D5 D6
d1: C:
ICU PWB
C: (1 d1) ×
+ d1 ×
D6
Example 1: Calculation of interpolation Supposing that the density of D5 at the normal ratio is 100 and that the density of D6 is 200, and that the position of new pixel C after zooming is at 50% position, the density of C is as shown below.
A
100 0
C
0.5 (50%)
B
200
d1
D7
= (1 0.5) × 100 + 0.5 × 200 d1 A d1 B
= 150 Density of new pixel C Example 2: In the case of enlargement In the case of enlargement of 200%, the image process is made so that the number of pixels will be twice as greater as the number of the scanned pixels. In short, the number of pixels scanned in the normal mode is duplicated to enlarge to 200%. One pixel in the normal mode is duplicated to two pixels in 200%. (Refer to the description below.)
A
D
G
(Normal)
B
C
E
F
H
I
(200%)
Then the density of pixels newly formed in the image process is determined. As shown in example 1, the position of newly made pixel is at the center (50% position) of two pixels scanned in the normal mode and the primary interpolation is performed as follows:
A= B
C=
A+ D
2
E= D
F=
D +G
2
In the image process, enlargement is performed only in the main scanning direction. In the sub scanning direction, the scanning sped of the optical system is changed to perform enlargement. (For example in 200% enlargement, the scanning speed is changed to 1/2, and 50% enlargement is performed by duplicating the scanning speed.) The main scanning is performed by image process, and the sub scanning by varying the speed of the optical system. Zooming in the main scanning direction is separately performed from zooming in the sub scanning direction. 16
Data flow (flowchart)
Content 30. FIFO This line memory (FIFO) is used for area separation and MTF correction. 31. Gate array 2 Performs area separation. In area separation, the characteristics of the target pixel and the neighboring pixels are judged to perform the optimum process. For example, judgement is made to identify that the area is a photo area or a hatched area such as newspaper photos.
30.
FIFO
31.
GA2
(Area separation)
32. Gate array 2 Corrects blurs in images in the main scanning direction and the sub scanning direction. Details are as follows. MTF meas Modulation Transfer Function of the optical system.
Original
32.
GA2
(MTF correction)
a
b
CCD
1 pixel (N)
ICU PWB
a: Theoretical value b: Value received by the CCD element (N) The optical system provides out of focus even the focus adjustment is perfectly completed. When the CCD elements receive reflected light from the document, the light leaks to the neighboring pixels by the optical system characteristics. On the contrary, light come in from the neighboring pixels. Correction is made by adding the leaked lights and subtracting the lights from the neighboring pixels. This correction is called the MTF correction. (In actual, this process includes calculation of the effect on the pixels by the preceding and the following lines. The MTF correction performs process to provide clear characters by edge emphasis if the area separation result is a character area, and to provide less emphasis if the result is a hatched area, and to provide smooth images if the result is a photo area. When the soft photo mode is selected, the area separation and the MTF correction are not performed, but the multi-value dithering is performed instead. The size of dither matrix in multi-value dithering can be selected by simulation. 33. Gamma correction SRAM Gamma correction is performed to make optimum copying of image data. In the photo mode, gamma correction is made to reproduce clear half tone images. In the manual mode, gamma correction is performed to provide clear copying of characters. Image data before correction are of 8 bit as well as image data after correction. (0 255) In the photo mode, line alignment is performed, where the gamma correction curve of the odd number pixels and the even number pixels in the main scanning direction are changed to reduce fluctuations in drive of the machine. In combination with the above area separation, it reduces bad effects of line alignment process for hatched documents. The gamma correction SRAM performs the highlight process. 34. Laser pulse width modulation The image data which are subjected to the gamma correction are converted into laser pulse signals (which varies the laser radiating time for each pixel.) Radiating time of laser can be changed in the unit of 1/256. 35. ECL circuit The laser pulse width signal is sent to the LSU at ECL level. 36. LSU The laser scan unit performs printing.
33. Gamma correction SRAM
(Irregular drive countermeasure)
34.
Laser pulse width modulation
35.
ECL circuit
36.
LSU
17
(2) Image process section
The image process section is composed of gate arrays A and B, the CPU, and memories (SRAM, FIFO, EPROM). Gate array A forms data for shading correction and calculates histogram data for automatic exposure. Gate array B performs area separation, filter process, address generation for self printing, multi-value dithering, and electronic zooming of main scanning. The CPU performs register setting and rewriting of LUT (look up table) every time when the user changes the mode. It also calculates the correction value of shading correction. The figure below shows the flow of image signals.
ICU image process section block diagram
EPROM (program) 64K x 8
EPROM (data) 256K x 8
SRAM (work) 32K x 8
CPU H8/3040 10MHz
Shading correction data
ICU CCD control section
Image data
Electronic zoom
Density conversion LUT SRAM 8K x 8
Gate array B Image data
FIFO
FIFO
5K x 8bit FIFO for reduction FIFO FIFO FIFO FIFO 5K x 8bit FIFO for area separation multi value dither
5K x 8bit FIFO for enlargement Visible sensitivity correction Automatic exposure Gate array A Shading correction data forming Histogram data calculation for automatic exposure
Area separation Multi value Dither Self print
Area separation data, self print data, multi value dither data, shading correction data by the neural net Multi function LUT SRAM 32K x 8
Filter process (MTF correction)
Gamma correction Black/white reverse Line alignment SRAM 8K x 8
ICU laser control section
Gamma correction LUT
Image data for calculation of shading correction data
[Shading correction]
The analog image data from the CCD PWB are inputted to the CCD control section in the ICU and converted into digital data, and passed through gate array A in the ICU image process section, and written into the multi-function LUT (Look Up Table). (Path shown with dotted line in the above diagram.) Gate array A performs thinning out of 16 lines at that time. Thinning out of 16 lines is performed when there is dirt on the shading plate.
[Electronic zooming]
The image data, after auto exposure and the visual sensitivity correction, are written into the FIFO for enlargement. Gate array B controls the enable signal for reading the enlargement FIFO to thin out the read data, enlarging images. For example, in enlargement of 200%, the read enable signal is provided for every pixel to make enlargement. The image data thinned out for enlargement are inputted to gate array B and the primary interpolation is performed as shown in 1-6. (For details, refer to 1-6.) The image data thinned out primarily are written into the reduction FIFO. The enable signal for writing is controlled to thin out for reduction.
[Auto exposure]
The analog image data from the CCD PWB are inputted to the CCD control section in the ICU and corrected by the shading data obtained from the above method and converted into digital data and inputted to gate array A. In gate array A, the total number data (simple histogram) of pixels in each density is calculated as shown in 1-5. The calculated data are used to judge that the document is of background type such as newspapers or of half tone type such as photos or of white type with less black and without half tone such as character documents. The data are calculated for each line. According to the data, the CPU selects the most suitable density conversion look up table from 32 kinds of density conversions look up tables in the density conversion LUT.
[Area separation]
After electronic zooming, the image data are written into the FIFO for area separation/filter/multi-value dithering. There are four FIFO's and each one sends data for one line. Therefore gate array B can input image data of five lines. Gate array B calculates the characteristic value of peripheral pixels according to the image data of five lines and the result is outputted to the address of the multi-function LUT. The multi-function LUT is the same one described in the shading correction. When the are separation mode is selected, the CPU reads the data for area separation from the EPROM (for data) and write into the multi-function LUT.
18
[MTF correction]
When the characteristic value outputted from gate array B is inputted to the address of multi-function LUT, data which show the characteristics of the peripheral pixels are outputted from the multi-function LUT. For example, the data show that the pixel and the peripherals are characters and edged of line drawing or that they are part of a hatched image of photo in a newspaper or that they are part of a photo of continuous gradation (that is not a hatched photo). Filter process is performed according to each pixel's characteristics.
No. 55 * 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 Function 82 83 O Data bus to the peripheral memory * connected to this LSI. O O O Data bus to the peripheral memory connected to this LSI. Data bus to the peripheral memory connected to this LSI. 84 85 * 87 88 89 90 * 92 93 * 100
Pin name XIFADR0 * XIFADR5 RAMRD VDD GND WCLK CLK1 XIFEN XIFRD XIFWR RESET VDD CLK2 RAMWR HSYNC PAGE RESERVE RESERVE RESERVE RESERVE GND RESERVE RESERVE RESERVE RESERVE GND H0 * H2 VDD GND V0 * V2 ADIN0 * ADIN7
I/O
Function
IN * Data bus to set the built-in register. IN OUT Read signal to the peripheral memory.
OUT Not used. IN IN IN IN IN System clock of this LSI. Clock of 16MHz is inputted. Data enable signal to the built-in register. Data read signal to the built-in register. Data write signal to the built-in register. Initializes the LSI. System clock of this LSI. Clock of 16MHz is inputted. Image data 1 line read start signal. Signal which shows the effective area of one page of image data.
[Gamma correction/line alignment/black-white highlight]
After the MTF correction, the image is subject to the gamma correction in order to cope with the OPC drum characteristics, the developing characteristics, and the actual copy density. Before copying, the CPU reads the density conversion look up table value corresponding to the value which was set by the user with the density adjustment key from the EPROM (data), and writes the data into the gamma correction LUT (SRAM). The image data are connected to the lower 8 bits of the gamma correction LUT address and converted by the look up table. Black-white highlight is performed at the same time.
IN
[Soft photo mode]
This is the multi-value dithering mode which has been newly added from this mode. The area gradation is combined with the pulse width modulation to improve the gradation of photo. The size of area gradation (dither matrix) can be selected with simulation.
OUT Write signal to the peripheral memory IN IN
[Self printing mode]
Gate array B prints out the test pattern by outputting the address count values of main scanning and sub scanning.
Not used.
Gate array A
Pin arrangement table
No. 1 2 * 7 8 9 10 11 12 13 14 Pin name GND RAMADR0 * RAMADR5 VDD RAMADR6 RAMADR7 GND RAMADR8 GND VDD O I/O
Not used.
OUT * Not used. OUT
OUT * Not used. OUT IN * Image data bus IN
15 RAMADR9 O Data bus to the peripheral memory * * * connected to this LSI. 20 RAMADR14 O 21 22 23 * 30 31 32 * 42 43 FINAL GND RAMADR0 * RAMADR7 GND XIFDAT0 * XIFDAT7 GND I/O * Data bus to set the built-in register. I/O I/O Address bus to the peripheral memory * connected to this LSI. I/O O Signal which shows the end of shading correction.
44 SHADOUT0 I/O Signal to output the data after shading * * * correction. 53 SHADOUT7 I/O 54 GND
19
Gate array B
Pin arrangement table
No. 1 2 3 * 10 11 * 14 15 16 * 19 20 211 22 23 * 30 31 32 * 34 35 36 * 39 40 41 * 48 49 * 52 53 54 * 57 58 59 60 61 62 63 * 70 71 * 78 79 80 * 87 88 89 * 94 Pin name GND VCC AIN0 * AIN7 RAMADR0 * RAMADR3 GND RAMADR4 * RAMADR7 VCC (fixed) GND (fixed) GND BIN0 * BIN7 RESERVED RAMADR8 * RAMADR10 GND RAMADR11 * RAMADR14 GND RAMDATA0 * RAMDATA7 FILOUT0 * FILOUT7 GND FILOUT4 * FILOUT7 CLK1 GND VCC GND (fixed) VCC (fixed) CIN0 * CIN7 XIFDAT0 * XIFDAT7 GND DIN0 * DIN7 RESET XIFADR0 * XIFADR5 IN * (n+3)the line image data input pin IN IN Reset signal of the LSI IN Address bus to select the built-in * register. IN 1 10 IN * (n+2)the line image data input pin IN I/O * Data bus to set the built-in register. I/O OUT Pin for output of the result of filter * process. OUT IN Clock signal input pin. Clock of 16MHz is inputted. IN Pin for data input from the external * LUT. IN OUT Pin for output of the result of filter * process. OUT Signals according to each mode OUT such as the result of area separation * are outputted to the external LUT OUT from this pin. IN * (n+1)the line image data input pin IN Not used. Signals according to each mode OUT such as the result of area separation * are outputted to the external LUT OUT from this pin. Signals according to each mode OUT such as the result of area separation * are outputted to the external LUT OUT from this pin. IN * (n) Line image data input pin. IN Signals according to each mode OUT such as the result of area separation * are outputted to the external LUT OUT from this pin. I/O Function
No. 95
Pin name AREALDLY
I/O
Function
Signal showing the effective image OUT area which is behind from AREA signal by 4 clocks. LOW active. IN IN Clock signal input pin. Clock of 16MHz is inputted. Data read signal to the built-in register. LOW active. Data write signal to the built-in register. LOW active. Data enable signal to the built-in register. LOW active.
96 97
CLK2 XIFRD
98 99 100 101 102 * 105 106 107 * 112 113 114 115 * 125 126 127 * 130 131 132 * 135 136 137
XIFWR XIFEN VCC (fixed) GND (fixed) BUNRIOUT0 * BUNRIOUT3 GND BUNRIOUT4 * BUNRIOUT9 GND CLK3 ZOOMIN0 * ZOOMIN10 GND ZOOMOUT0 * ZOOMOUT3 GND ZOOMOUT4 * ZOOMOUT7 GND VCC
IN IN
OUT * Area separation test pin. OUT OUT * Area separation test pin. OUT Clock signal input pin. Clock of 16MHz is inputted.
IN
IN * Zooming process data input pin. IN IN * Zooming process data input pin. IN IN * Zooming process data input pin. IN
IN 138 ZOOMOUT8 * Zooming process data input pin. * * 140 ZOOMOUT10 IN 141 142 143 144 145 146 * 148 149 FIFOWEN VCC (fixed) GND (fixed) GND FIFOREN RAMDLY0 * RAMDLY2 AREAHDLY OUT Read enable signal to the line memory. LOW active. OUT Write enable signal to the line memory. LOW active.
OUT 10-clock behind signal of * RAMDATA0 2. OUT Signal showing the effective image OUT area which is behind from AREA signal by 5 clocks. LOW active. IN OUT Image data 1 line scanning start signal Signal which shows the effective image area. LOW active.
150 151 152 * 159 160
HSYNC AREA EIN0 * EIN7 PAGE
IN * (n+4)the line image data input pin. IN IN Signal which shows one page of image data. LOW active.
[2] PROCESS SECTION
Dark area Dark area
Light (Laser)
(OPC drum, cleaning unit) 1. Outline
The indirect electrostatic copiers use normal paper for copying, and form electrostatic latent images on the OPC drum surface which can be used repeatedly, develop them into visible images (toner images), and transfer them on copy paper. Copies are made indirectly in the copier of this type. The PPC (Plain Paper Copier) makes copies in six processes: charging, exposure, developing, transfer, discharging, and cleaning which cleans the OPC drum surface to use is repeatedly after transfer.
CTL
CGL Base
Principle of photoconductor (conductivity)
(3) Kinds of photoconductors
Major photo conductive materials used in the copiers are zinc oxide (ZnO), amorphous selenium (amorphous Se) alloy, cadmium sulfide (CdS), amorphous silicon (amorphous Si), and organic photoconductor (OPC).
Amorphous selenium (non crystal Se)
(1) Image forming process
1 Charging 2 Exposure
Discharging
6
OPC drum
Selenium alloy Non0organic photoconductor Zinc oxide (ZnO) Cadmium sulfide (CdS) Amorphous silicon (Non crystal Si) Organic photoconductor Organic photoconductor (OPC)
3 Developing
Cleaning
5 4
Transfer
1 The OPC drum is charged. 2 The OPC drum is exposed to form electrostatic latent images. 3 Toner is attracted to the electrostatic latent images. 4 The developed toner images are transferred on recording media
such as paper.
The compositions of photoconductors used in the copiers are shown below. Zinc oxide (ZnO) master
Photoconductive layer (zinc oxide layer) Intermediate layer Paper Base paper Back coating paper
5 Residual toner remaining on the OPC drum surface is cleaned. 6 Residual charges on the OPC drum are removed.
Cadmium sulfide (CdS) drum
(2) OPC drum
Some materials conduct electricity, and some others do not. The materials are divided into three groups according to their conductivity: conductors, semiconductors, and insulators. This classification is not strict, and it is difficult to classify the materials strictly. Generally speaking, the materials with resistivity of 108 cm or above are called insulators. Those with resistivity of 103 cm or below are called conductors. The materials between the two are generically called semiconductors. The conductors are always conductive. The semiconductors are normally not conductive, but under a certain condition become conductive. The photoconductor used in the copiers are insulators when they are not exposed with light, and reduce the resistivity when they are exposed with light, that is, they become conductive (by the photo conductivity phenomenon) when exposed with light. They are also called as photo semiconductors and used in the copiers.
PET layer Micro space layer Photoconductive layer (CdS layer) Aluminum layer
Organic photoconductor (OPC) master or drum
Organic photo Carrier transfer layer Carrier generation layer conductive layer Aluminum layer (OPC layer)
Selenium (Se) drum)
Photoconductive layer (selenium layer) Aluminum layer
21
Characteristics of organic photoconductors (OPC)
[Acceptance potential]
The dark resistance of the photoconductor layer decreases as the electric field applied between layers increases. When the photoconductor is charged, the electric field is formed to a high level and the resistance of the layer decreases to restrict the charging amount of the photoconductor. The potential of the photoconductor at that time is called the acceptance potential, which serves as an important factor to determine the potential contrast. The photoconductor is generally charged to a potential slightly lower than the acceptance potential in order to avoid applying an electrical strain to the photoconductor.
· · · · · · ·
Can be formed into various shapes (drum, sheet, belt) High insulation in a dark place. (Acceptability and retainability of charges) Light weight Stable against humidity and temperature Safe and clean to the environment (harmless) Weak in wear by friction Weak in durability against light and ozone
[Charge retainability]
(4) Characteristics of photoconductors
The important characteristics of photoconductors are as follows: 1. Photo sensitivity 3. Acceptance potential 5. Residual potential 2. Spectrum characteristics 4. Charge retainability 6. Fatigue
[Photo sensitivity]
It is determined by the attenuation speed of the potential when exposed with light.
The retaining time of electrostatic latent images on the photoconductor is determined by the speed of decrease in the potential in a dark place. That is, it is measured with the time for the photoconductor potential to decrease to the half of the initial level. This retainability of electrical charge makes a problem when the interval time between exposure and developing is longer. In the machines where a series of operations of charging, exposure, and developing are automated, the interval between the processes is short enough and there is no problem.
[Residual potential]
When the charged photoconductor is exposed, the potential is rapidly attenuated at first then slowly. The potential where this slow attenuation starts is called the residual potential. The lower the residual potential is, the greater the voltage contrast is. Therefore, the lower residual potential is desirable.
[Spectrum characteristics]
The sensitivity of photoconductors differs depending on the kind and the waveform of light.
Se:Te
Amorphous silicon
1.0
0.8
OPC for digital
[Fatigue]
When the photoconductor is charged and exposed repeatedly, it is fatigued. Fatigue of the photoconductor results in increase in attenuation speed of the photoconductor potential and decrease in the retainability of charges. In the above, the necessary characteristics for the photoconductors are described. In an actual machine, when charging is repeated by the charger, dust and dirt or splashed toner may be attached to the saw tooth. These are not resulted from uneven charging, and they should be removed by cleaning.
Sensitivity
0.6
0.4 0.2
OPC for analog
500 600 700 800 900
400
Wavelength (nm)
Spectrum sensitivity
Relationship between color and waveform Human eyes can feel the lights with waveform of 380nm to 780nm. These are called "Visible lights." The light whose waveform is shorter than that is called "Ultraviolet light." The light whose waveform is longer than that is called "Infrared light." The figure below shows the relationship between lights and waveforms.
Blue green Ultraviolet
350
Orange
Green
Violet
Yellow
Blue
Red
650 700 750
Infrared
800
400
450
500
550
600
22
2. Basic process and composition
·
This machine employs the scorotron system to charge the photoconductor surface uniformly to a certain level. The conventional corona charger mechanism is employed which is composed of the corona wire and the saw tooth plate (stainless plate of 0.1mm thick). In corona charging, oxygen molecules in the air are ionized to form ozone. This mechanism suppresses the generation of ozone. The process separation mechanism is employed for serviceability. The one-touch stopper mechanism prevents against high voltage leakage caused by drop of the corona charger unit.
( 5.25KV) MC
Screen grid Main charger output section
· ·
Grid voltage output section
High voltage unit
LD 785nm EXP
Drum mark sensor
Step 2: Exposure (laser beams)
Laser beams are generated in the LSU according to the print signal from the ICU and radiated to the drum surface. The resistance of the are of OPC layer where laser beams are radiated reduces to discharge negative charges, forming electrostatic latent images on the drum surface.
Fuse bulb
DL
Toner Carrier
DV unit
Exposure
Developing bias
400V
Exposure (laser beam)
Process control sensor
SC AC 5.2KV (DC 400V)
TC It ( 180µA 5.3KV)
OPC layer Pigment layer Aluminum layer (drum)
Drive system view
Non image area Image area
Non image area
Image area
(1) Details of image forming process
Step 1: Charging Main charger high voltage transformer (MHVG)
Grid voltage Standard mode Photo mode TSM mode Printer mode 490V 490V 440V 460V Developing bias voltage 400V 400V 350V 400V
Step 3: Developing (Bias 400V)
The electrostatic latent images on the drum surface are made visible images. This model uses the two-component magnetic brush developing system to supply the bias voltage of 400V to carriers (MG roller), and toner is negatively charged by friction with carriers. Since the non-image area on the drum is negatively charged greater than the developing bias, the negatively charged toner is repulsed from the drum. The image area on the drum is exposed by laser beams and its potential is decreased. Then negative toner is attached to it by the DV bias.
Carrier Toner
A uniform negative charge is applied to the OPC drum surface by negative corona discharge of the main charger. The OPC drum surface potential is controlled by the screen grid voltage to be virtually the same level as the grid voltage.
·
When the drum surface potential is lower than the grid voltage, electric charges generated by discharging of the main charger are passed through the screen grid to keep charging until the drum surface potential reaches the same level as the grid voltage. When the drum surface potential reaches about the same level as the grid voltage, electric charges generated by discharging of the main charger flow through the electrode of the screen grid to the high voltage unit grid voltage output circuit. Therefore the drum surface potential is kept at the same level as the grid voltage.
S
N N
·
N
S
-400V
23
Step 4: Transfer
The visible images on the drum surface are transferred to copy paper. Positive corona of the transfer charger is applied to the back of the copy paper to transfer toner on the drum to the copy paper.
Toner
Step 7: Discharge
The discharge lamp light is radiated to the drum to reduce the electric resistance of the OPC layer, eliminating the residual charges.
Discharge lamp
Paper guide Copy paper
Transfer charger output section High voltage unit
(3) Potential transition of the DV unit section
0 Start
Print potential Toner attachment potential
Step 5: Separation
Since the copy paper is positively charged and the drum is negatively charged after transfer, an attraction force is generated between the drum and the copy paper. Then an AC corona overlapped with negative DC is applied to the copy paper to decrease the copy paper potential to the same level as the drum surface potential. Therefore an attraction force between the drum and the copy paper disappears, and the copy paper is separated by its own flexibility. If the paper is not separated by the separation charger, it is forcibly separated by the separation pawl.
Developing bias
(-V) Time Drum
Toner attachment D.S.P. 0V DV.Bias ON
Drum surface potential
MG roller Toner Carrier
0V
-400V
Separation pawl
Carrier attachment D.S.P. -550V DV.Bias OFF
Copy paper
-550V
0V
Separation charger output section
Image area D.S.P. -70V DV.Bias ON
-70V
-400V
High voltage unit
Non image area D.S.P. -550V DV.Bias ON
-550V
-400V
Step 6: Cleaning
Residual toner on the drum is removed by the cleaning blade.
Cleaner blade
DSP: Drum surface potential
Residual toner
24
(4) OPC drum sensitivity reduction correction
(New) (After use) Wear
CTL CGL CTL CGL
In the AR-5132, deterioration of copy quality is prevented by correction with the charging grid voltage against the potential reduction of the OPC drum due to repeated use. The drum wear increases the grid voltage to maintain the drum surface potential at a constant level, and the apparent sensitivity of the OPC drum is decreased. To correct this, the laser beam strength is increased when the coefficient of the drum rotating time for correction of the charging grid voltage reaches a certain level.
CLV
Cleaner section
Grid voltage correction value
Developing section
0 1 2 3 4 5 33 34 35
OPC drum
Coefficient for rotation time
Process control
1 Toner patch images are formed on the OPC drum surface under
the three kinds of conditions (MC grid bias voltage) and the developing bias. (The voltage is an actually measured value.)
(5) Process control function
[Outline]
The density of the reference toner image formed on the OPC drum surface is used as the standard patch density, and the developing bias and the charging grid voltage are controlled to provide the same density as the standard patch density for stabilizing the copy images. That is, the process conditions are set, and the high voltage output is changed and corrected so that the toner density is stabilized under the conditions.
In the process control, toner patch images are formed at the laser output of the reference grid voltage (410V) and the developing bias (240V) ±50V and duty of 100%.
2 The three kinds of toner patch images and the drum surface are
measured with the process density sensor to obtain the relationship between them.
Potential (V) Surface
Toner image
Surface
Toner image
Surface
Toner image
Surface Drum surface potential
F
Developing bias
R
Main control PWB CPU density judgement I/O MC grid developing bias output selection
Process density sensor PWB Density detection level setting (VR2) High voltage PWB Each mode MC grid developing bias output (density correction) (Light quantity correction)
Light potential
1
BV 2
3 3 2 1
BS1 PT1 PT2
BS2
BS3
PV
PT3
25
3 The developing bias voltage is obtained from comparison with the
standard patch density.
Drum marking In the AR-5132, toner patch images are formed at the same position on the OPC drum to improve accuracy of the process control. That is, a marking is provided on the drum, and the marking point is sensed and toner patch images are formed at a certain position. If the marking is not sensed, the copy density is extremely reduced.
255 R 1
Standard patch density
2 3
R1=PT1/BS1 x 255 R2=PT2/BS2 x 255 R3=PT3/BS3 x 255
0 -290 -240
V GB PAT -190
R F
Developing bias voltage (V)
In the AR-5132, the absolute value of the density sensor output value is not directly used for the control calculation, but the ratio of the drum surface sensor output value (BSn) and the toner patch image sensor output value (PTn) is used for the control calculation. Since the ratio of PTn/BSn) is not affected by the change in the absolute value of the light quantity of the reflection type sensor due to dirt or deterioration, stable control is performed.
4 In the developing bias/MC grid voltage correction, the value of vV
of the developing bias voltage calculated with the standard patch density and the process control is fed back to the bias voltage and the MC grid voltage in each mode. When the developing bias voltage is corrected, the corresponding MC grid bias is calculated and controlled.
5 When a value reaching the reference level is not obtained in a
series of control procedures, the patch forming conditions are shifted toward the reference level side and repeat the series of control procedures. The repetition is allowed for max. five times. LD power correction The LD power correction is performed depending on the result of the developing bias voltage calculation. When the correction width üV of the developing bias voltage becomes greater, the MC grid voltage is corrected accordingly. If the LD power is the same at that time, the apparent sensitivity of the OPC drum is changed. To correct this, the LD power is made greater when the developing bias voltage is increased; on the contrary the LD power is made smaller when the developing bias voltage is decreased. The width of decrease or increase is determined according to the built-in table. This correction stabilizes half tone prints. Process control timing In the AR-5132, the process control is performed at the following timing. a. When the power switch is turned on. (during warming up) b. When the accumulated copy time reaches 30 min, the process control will be made in the next copying. c. When the standby time reaches 1 hour, the process control will be made in the next copying. d. When simulation 46 is executed.
26
[3] DEVELOPING SECTION
1. Basic outline
(1) Two-component developer
Developer is composed of tow components; toner and carrier. Carrier functions as a media to attract toner to electrostatic latent images on the OPC drum. As the toner is mixed with the carrier, the friction changes it to positive or negative. Developer characteristics changes due to deterioration to degrade print quality. Therefore developer must be replaced periodically.
2. Basic composition
2
1
4
3
5
(2) Two-component magnetic brush developing
A rotatable non-magnetic sleeve is provided on the magnet roller and rotated. Carrier forms a magnetic brush on the sleeve surface by the magnetic force to attract toner to electrostatic latent images on the OPC drum. No. Name Forms the magnetic brush of carrier by the magnetic force. Used of regulation of the magnetic brush height. Stirs carrier in the developing unit to distribute toner uniformly. the toner hopper unit to the stirring section.
1 Developing magnet roller 2 Developing doctor blade 3 Developing stirring roller
(3) Developing bias
Since the reverse developing system is employed, toner is attracted to the area (light potential area) where laser beams are radiated. Though it is the light potential area, the OPC drum is negatively charged. To attract negatively charged toner to the OPC drum, a higher (absolute value) bias must be applied to the MG roller. Therefore, the amount of attracted toner can be varied by the level of the developing bias voltage. The developing bias serves to prevents against attachment of excessive toner by setting it lower (in absolute value) than the surface potential (dark potential) when making white background.
4 Developing transport roller Transports toner supplied from
5 Developing toner density
sensor
Detects the toner density in the developer.
3. Basic operation
When the power switch of the machine is turned on, the machine starts warming up. After about one minute, the main motor rotates. The drive power of the developing unit is transmitted from the main motor through the main drive unit to the developing drive unit. Change in the mixing ratio of toner and carrier is sensed by the toner density sensor in the developing unit as the change in magnetic permeability, and outputted to the analog input pin of the main PWB CPU of the main body. The CPU monitors the input voltage level, and controls the main motor and toner motor to supply, transport, and stir toner until the proper density is obtained.
31
[4] PAPER FEED SECTION
1. Basic outline
The AR-5132 employs the font loading system and the multi paper feed table which can be stored inside the machine, cutting the installation space. It is also equipped with the two-step trays, the 3000sheet LCC tray, and the manual paper feed tray which allows continuous feeding of 50 sheets as standard provisions.
2. Basic composition
1 2 16 15
14
13
12
11 10
Main body Main body
ADU Paper tray 1 (500 sheets) Paper tray 2 (500 sheets) Paper tray 3 (3000 sheets) LCC type
Manual feed tray 50 sheets
9 3 4 8 7 6
5
Desk unit
No.
Name Resist roller (PPD2) Paper transport sensor (LUD3) Lift upper limit sensor (PED3) Paper empty sensor Pick-up roller Paper feed separation roller Paper feed roller (PID) Paper entry sensor Transport roller Transport roller (TFD) Wast toner fll sensor (PED1) Paper empty sensor Pick-up roller Paper feed roller Paper separation roller (PPD1) Paper transport sensor
Function, operation Makes synchronization between paper and images by control of the resist roller clutch. Used to control the transport roller clutch (TRC). Used to control the lift-up motor. Stopped at HIGH. Used to detect paper empty. Picks up paper and falls simultaneously with turning on the paper feedf solenoid. Preents agaisnt multi paper feed. Paper feed roller for the paper tray 1, (Includes the one-way clutch.) Detects pper entry from the paper tray 1 and turns off the paper feed solenoid. Transports paper from the paper tray 1. Transoprts paper from the cassette to the resist roller. Full at LOW. Detects paper empty in the manual paper feed mode. Paper present at LOW. Manual feed peper pick-up roller. Manual paper feed roller (Includes the one-way clutc.) The manual paper feed separation roller prevents agaist multi paper feed. Detects paper entry from the main body or the desk.
1 2 3 4 5 6 7 8 9 F G H I J K L
41
3. Basic operation
(1) Manual paper feed section operations
1 Before the operation of the manual paper feed section, the
manual paper feed solenoid (MPFS) is OFF and the manual paper feed stopper is closed and the paper pick-up roller is up. The latch and the clutch are at positions as shown in the table below.
3 When the manual paper feed clutch sleeve pawl C is caught by
the manual feed latch, the manual fed stopper falls and the manual feed pick-up roller rises. At the time, the transport roller is rotating.
Manual paper feed pick-up roller Manual paper feed stopper
Manual paper feed stopper
Transfer paper
Manual paper feed pick-up roller Transfer paper
Manual paper feed roller
Manual paper feed roller Manual clutch sleeve A Manual paper feed clutch sleeve
Manual pressing plate Manual paper feed clutch sleeve
A B C
Manual paper feed latch A Manual paper feed solenoid
C A B
Manual paper feed clutch sleeve A Manual paper feed latch A Manual paper feed solenoid
Manual paper feed latch
ON
Manual paper feed latch
4 When the tip of the transferred paper is detected by PPD2, the
manual paper feed solenoid is turned off after about 0.2 sec. At that time, the clatch sleeve pawl B is caught by the manual paper feed latch.
2 When the start button is pressed, the manual paper feed solenoid
(MPFS) is turned on, and the manual paper feed latch A is disengaged from the manual paper feed clutch sleeve A, and the manual paper feed roller and the manual paper feed pick-up roller rotate. At the same time, the manual paper feed stopper is opened and the manual paper feed pick-up roller is pressed on the paper to start paper feed.
As a result, the paper is warped between the resist roller and the paper feed roller.
Manual paper feed pick-up roller Manual paper feed stopper Resist roller
Manual paper feed stopper
Transfer paper
Manual paper feed roller
Manual paper feed pick-up roller
Manual paper feed clutch sleeve
Manual paper feed roller Manual paper feed clutch sleeve A Manual paper feed latch A
A B
Manual paper feed clutch sleeve A
Manual paper feed latch
C
Manual paper feed clutch sleeve
C
A B
OFF
Manual paper feed solenoid
Manual paper feed latch
ON
Manual paper feed latch A Manual paper feed solenoid
42
5 The manual paper feed solenoid is turned on for 0.08 sec in
synchronization with rotation of the resist roller, and the manual peper feed roller is rotated. Therefore, paper jams due to insufficient pick-up of the resist roller is prevented. At that time, the manual paper feed pick-up roller remains up.
Manual paper feed pick-up roller Manual paper feed stopper Resist roller
1 Lift up
When the power is turned on, the main circuit checks the sensors. The lift up motor is turned on/off to make ready for paper feed according to the states of the paper empty sensor (PED) and the lift-up senosr (LUD).
Power ON
Transfer paper
PED/LUD "ON" NO
Manual paper feed roller Manual paper feed clutch sleeve A
YES
LUM ON
Manual paper feed clutch sleeve
A
B
Manual paper feed latch A
CPF2 turns ON, the pick-up roller presses the copy paper to start paper feed.
Manual paper feed latch
ON
Manual paper feed solenoid
6 The manual paper feed solenoid is turned off and the clutch
sleeve pawl A is caught by the manual paper feed latch and the mamual paper feed is completed.
Manual paper feed clutch sleeve Manual paper feed clutch sleeve A
A B
2 Paper feed
Manual paper feed latch A Manual paper feed latch
OFF
Manual paper feed solenoid
When the start button is pressed, the cassette paper feed solenoid (CPFS2) and the cassette paper feed roller clutch (CPFC2) are turned on. By turning on the solenoid, the paper feed pick-up roller is pressed down to press the paper. By turning on the clutch, the paper feed roller and the pick-up roller start the paper feed operation. The fed paper is passed through the paper entry sensor (PID) to the transport roller. the transport roller is rotated by two drive clutches. For transport from the paper feed section to the resist roller, It is driven by the high speed clutch. The resisted paper is transported to the process section in synchronization with the optical system. The transport speed at that time is switched from the high speed clutch to the low speed clutch so that the transport speed becomes the same as the process rotating speed.
MM\
Main motor
1sec MM\
Main motor
PPD1\
Transport sensor 1
PPD2\
"À`-- 'm sensor 2 Transport Z " T2
TRCL\
Transport clutch `('á`¬) "À`-- N b (low speed)
TRCH\
Transport b (high speed) "À`-- N clutch`( `¬)
MPFS\
Manual paper feed solenoid
RRC\
Resist roller clutch
PPD1
Transport sensor 1
Manual paper feed timing chart
PPD2
Transport sensor 2
TRCL\
Transport clutch (low speed)
(2) Cassette paper feed section operations
The cassette paper feed operations are the same in the paper tray 1 and the paper tray 2. The following descriptions are based on the paper tray 1.
TRCH\ (high Transport clutch speed)
RRC\
Resist roller clutch
LCPFS\
Lower cassette transport solenoid
LCPFC\
Lower cassette transport clutch
Lower cassette paper feed timing chart
43
[5] TRANSPORT AND FUSING SECTIONS
Stirring roller
Drum unit Drum motor
Main motor
Main drive unit
Fusing unit
DV drive unit
Cleaning roller
1. Outline
The AR-5132 allows paper transport of max. A3 (11" × 17") to min. A5 (8 1/2" × 5 1/2"). After transfer of images, the paper is separated from the drum and transported to the fusing section by rotation of the resist roller and the transport belt. The transport section is provided with the separation sensor (PSD). This sensor detects separation of paper and is used for taking the drive timing of the duplex gate solenoid (DGS) after fusing.
MG roller
Cleaner unit Suction unit Reverse roller
PS roller Paper exit roller Multi paper feed unit
ADU drive unit
Transport roller (upper) Transport roller (lower)
Paper feed speed change unit (High speed) (Low speed)
Paper feed unit
Auto duplex copy unit
Paper feed drive unit
2. Basic composition and functions
(1) Transport section
1 Transport belts (2 pcs.)
The transport belts are corrugated to push the rear edge of paper.
Paper Transport direction
Paper feed unit
[6] HIGH VOLTAGE SECTION
1. Outline
There are three kinds of chargers; the main charger, the transfer charger, and the separation charger. The main charger employs the scorotron system. The drum surface is charged negatively and uniformly by electric charges controlled by the screen grid which is positioned between the charger and the drum. The transfer charger is used to transfer toner images which are on the drum to the copy paper. A negative high voltage is applied to the back of the copy paper. The separation charger applies AC corona to the copy paper to eliminate a potential difference between the drum in order to perform separation.
Transport belt
2 Separation sensor (PSD)
This is a transmission type photo sensor and is attached to the chassis of the main body.
3 Suction fan motor and ozone filter
Ozone generated in the process high voltage section is absorbed by the filter.
(2) Fusing section
1 Upper heat roller
This roller is teflon-coated in the shape of a reversed crown.
2. Basic composition
(1) Main charger high voltage transformer (MHVG)
Grid voltage Standard mode Photo mode TSM mode Printer mode 490V 490V 440V 460V Developing bias voltage 400V 400V 350V 400V
2 Lower heat roller
This roller is a silicon rubber roller in the shape of a crown.
3 Upper cleaning roller
This roller, impregnated with silicon oil, is used to remove dirt from the upper heat roller to provide better separation of paper and lengthens the life of the heat roller.
4 Separation pawl
Four separation pawls which are teflon-coated are used for the upper heat roller for reducing friction. Two separation pawls are used for the lower heat roller.
5 Upper/lower separation function
The upper heat roller section and the lower heat roller section can be separated from each other for better serviceability.
(2) Transfer charger high voltage transformer (THVG)
+13.5µA (Electrode sheet front/rear balance difference: within 3µA)
6 Division of the drive system
The fusing unit is driven by the main drive unit. Since the fusing section is manually fed in case of a paper jam, a spring clutch is provided in the main drive gear to prevent that an excessive load is applied to the gears.
(3) Separation charger high voltage transformer (SHVG)
DC component voltage: 400±10V
51
[7] RADF MECHANISM SECTIONS
1. Operation flowchart
The figures below show the transport path of an document from the document setting, through paper feed, copying, to paper exit. For details of operations, refer to the operation process.
Original stopper A21 weight plate Semi-circular roller Paper exit roller Flapper
* B
Step 10: Step 11: Step 12: Step 13: Step 14: Step 15: Step 16:
Reverse sensor (RDD) senses the lead edge of the discharged document. (RDD output HIGH) Document feed sensor (DFD) senses the lead edge of the discharged document. (DFD output HIGH) Paper feed motor (DFM) OFF The document is stopped by the resist roller. Paper feed motor (DFM) reverse rotation (Resist roller rotation) The lead edge of the document is taken up by the resist roller.) Document width sensor (DWS) senses the document width. (Output LOW) Document timing sensor (DTD) senses the lead edge of the document. (DTD output HIGH) Paper feed motor (DFM) OFF (The document is stopped with its lead edge taken up by the resist roller.) Reverse sensor (RDD) senses the rear edge of the discharged document. (RDD output LOW) Reverse motor (DRM) rpm down Transport motor (DTM) OFF (Transport stop) Document discharge Reverse motor (DRM) OFF (Reverse roller, paper exit roller stop) (Paper feed reverse)
Separation roller
Resist roller
Transport belt drive roller Paper feed roller
Original transport belt
Reverse transport belt roller follower roller
1) RAD mode (duplex copy mode) copying
START Step 01: Step 02: Step 03: Step 04: (Preliminary paper feed): Step 05: Step 06: Step 07: * A Step 08: Step 09:
The transport section is closed. (AUOD ON) An document is set on the document tray. (DSS output HIGH) Document feed display ON Print SW ON * A: For the first document, dummy paper exit is performed. Paper feed motor (DFM) forward rotation (Paper feed roller, semi-circular roller rotation) Since the stopper is up, paper feed is not performed. Reverse motor (DRM) forward rotation (Reverse roller, paper exit roller rotation) Transport motor (DTM) rotation (Transport belt rotation) * B: If there has been an document on the tray, is discharged. Paper feed motor (DFM) OFF Paper feed solenoid (DFSOL) ON (The weight plate and the stopper move down to press the document onto the semi-circular roller.) Paper feed motor (DFM) forward rotation (Paper feed roller, semi-circular roller rotation) The document feed is started. * B * B
Step 17: Step 18: Step 19: Step 20: (Preliminary paper feed): Step 21: Step 22: Step 23:
* A
Transport motor (DTM) forward rotation Tran