JPS60233672A - Recorder - Google Patents

Abstract

PURPOSE:To prevent generation of a region where a developer does not stick to the surface of a recording medium for a long period on said surface by providing a means for forming an image in the part of the recording medium except the region to be transferred at every recording on a prescribed number of paper. CONSTITUTION:A photosensitive body 301 is recorded with information thereon by a beam and an electrifying means 304 and electrifies uniformly the body 301 to prescribed potential. A transfer means 305 transfers a developer toner to paper. A developing means 307 is a developing device and an exposing means 311 exposes the medium 301. On the other hand, paper feed means 318 is an upper feed roller for taking out each sheet of paper from an upper cassette and a means 327 is a feed roller for manual insertion to be used to convey said paper after the insertion of said paper is confirmed. A line is formed in the region except the region to be transferred on the paper at every recording of a prescribed number of paper and therefore the toner sticks to said region. The generation of the region where the toner does not stick to the surface of the photosensitive body for a long time on said surface is thus prevented.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a recording device, in particular, to recording information by scanning a recording photoreceptor, which is a recording medium, and developing the recorded latent image onto a sheet of paper. The present invention relates to a recording device that performs recording by transferring toner and fixing the toner onto the paper using heat.

[Technical background of the invention and its problems] In a recording device that charges a recording photoreceptor, develops a latent image on the photoreceptor on which information is recorded by beam scanning, and transfers it to paper, the photoreceptor is The laser beam is not necessarily irradiated over the entire length in the axial direction, and especially when printing on small-sized paper (for example, B5 or A4 size), the laser beam may not be irradiated over the entire length of the photoreceptor. Since the laser beam is not irradiated on the photoreceptor, toner, which is a developer, does not adhere to that area, resulting in a region on the photoreceptor where toner does not adhere for a long time. This problem also occurs when printing on large-sized paper. Then, if there are areas where toner does not adhere for a long time,
When the toner adhered to the photoreceptor is scraped off with a cleaning blade after recording is completed, the contact resistance of the blade becomes large in the non-adhered area, resulting in damage to the photoreceptor surface and even the cleaning blade. [Object of the Invention] An object of the present invention is to prevent the formation of areas on the surface of a recording medium to which no developer adheres for a long time, and to further prevent the surface of the recording medium and the cleaning blade from being scratched.

[Summary of the Invention] In order to achieve the above object, the present invention provides means for forming an image on a portion of a recording medium other than the area to be transferred each time an image is transferred onto a predetermined number of sheets of paper.

(The following is a blank space) [Embodiment 1 of the Invention Hereinafter, a description will be given with reference to an illustrated embodiment to which the present invention is applied.

FIG. 1 is a block diagram of a system for recording information on a recording medium by means of a laser beam. A host side system 1 (electronic, it i m,
The information from the wordbook U seza main body, etc.) is given to the data control section 2. The data control unit 2 converts the information given from the host system 1 into data corresponding to dots and stores it in the page memory.

This stored dot image data is transferred to the print control unit io.
Send to o.

The print control unit 1oo writes the input dot image data onto a recording medium by modulating a laser beam, develops and transfers it, and prints the dot image data on a recording sheet.

FIG. 2 shows a detailed mechanical diagram of a printer 300 with a video interface.
It has a built-in printing control section 100 shown in the figure.

In FIG. 2, 300 is the printer body, 301 is
photoreceptor for recording information by laser beam,
Reference numeral 302 denotes a charge removal lamp for removing the charge on the photoreceptor 301 to an initial state, and is composed of a plurality of red LEDs. Numeral 303 is a static elimination lamp for increasing transfer efficiency, and like the static elimination lamp 302, it is composed of a plurality of red LEDs.

304 is a charger for uniformly charging the photoreceptor 301 to a predetermined potential; 3o5 is the photoreceptor 301;
A transfer charger 306 is for transferring the developed toner onto the paper, and a peeling charger 306 is for separating the paper after transfer from the photoreceptor.

307 is a developing device for developing an electrostatic latent image written on the photoreceptor 301 by a laser beam;
08 is a component of the developing device 307, and is a magnet roller for attaching the toner to the electrostatic latent image on the photoreceptor 301, which rotates in the direction of the arrow.

309 is an auto-toner probe that comes into contact with the developer of the magnetic roller and measures the toner specific density of the developer, and 31o is a cleaning blade that removes toner remaining on the photoreceptor 301 after transfer. .

311 is the video data input from the data control unit,
A laser scanner unit t-, 312 for scanning, modulating and recording a laser beam on the photoreceptor 301 includes an octahedral polygon mirror 313 for guiding a laser beam from a laser diode onto the photoreceptor 301.
314 is a scan motor for rotating the polygon mirror 312 at high speed; and 314 is an f/θ lens for keeping the scanning speed of the laser beam on the photoreceptor 301 constant. 315 and 316 are the scanner units 3;
This is a reflecting mirror for guiding the laser beam from 11 to the photoreceptor 301.

317 is an upper cassette that can hold 500 sheets of paper.
318 is an upper paper feed roller for taking out sheets of paper one by one from the upper cassette 317; 319 is an upper paper out switch that detects when there is no paper in the upper cassette 317; This is an upper cassette size detection switch consisting of 4 bits for detecting a size identification mark. Reference numeral 321 indicates a lower paper feed roller, 323 indicates a lower paper out switch, and 324 indicates a lower cassette size detection switch. In addition, the upper section can store 250 sheets of paper from the lower section, and can also be used with cassettes.

325 is a manual feed switch that detects the paper inserted from the manual feed guide 326; 32゛l is a manual paper feed roller that conveys the paper after the insertion is confirmed by the manual feed switch 325;
Reference numeral 28 denotes a manual stop switch that detects the paper conveyed by the manual paper feeder 327.

Reference numeral 329 denotes a registration roller for synchronizing the image developed on the photoreceptor 301 and the paper.

330 is a conveyor belt for conveying the paper separated by the peeling charger 306 to a fixing device; 331 is a fixing device for fixing the transferred toner on the paper;
332 is a fixing roller, 333 is a heater lamp for heating the fixing roller, 334 is a thermistor for detecting the surface temperature of the fixing roller, 335 is a discharge roller, and 336 is paper discharged from the fixing device 331. This is a paper ejection switch for detecting paper that has been removed.

337 is a cooling fan for cooling the inside of the printer 300, and 338 is the charging charger 304 and the transfer charger 305. A high-voltage transformer that generates high voltages to be applied to the peeling charger 306, the developing device, and the magnet roller 308, respectively.

339 is a power supply device that generates DC voltages used for each control, and 340 is a PC board unit that controls the printer 300.

342 is a photoconductor 301 provided near the photoconductor 301;
A thermistor with extremely low thermal resistance is used in a drum temperature sensor to detect the temperature i of a drum.

FIG. 3 is a perspective view schematically showing a portion for recording information on the photoreceptor 301 using a laser beam. In FIG. 3, a laser beam emitted from a semiconductor laser 344 is corrected into parallel light by a collimator lens 343, and the parallel light is applied to one surface of an octahedron of a polygon mirror 313. Since the polygon mirror 313 is rotated at high speed in the direction of the arrow by the scan motor 312, the laser beam incident on the polygon mirror passes through the [.theta.
48 ranges are scanned from left to right. A part of the laser beam within the beam scanning range 348 is reflected by the reflecting mirror 3.
45 to a beam detector 346. Therefore, each time one horizontal scan by one surface of the polygon mirror 313 is performed, the beam detector 346 detects the laser beam being scanned. Further, the laser beam that is not incident on the reflection mirror 345 within the beam scanning range 348 is irradiated onto the photoreceptor 301 . In FIG. 3, the location where the laser beam is scanned on the photoreceptor 301 is shown at 349. 30
Reference numeral 4 indicates a charging station 17, and 347 indicates a sheet of paper. In addition, the size shown in FIG.
1 rather than the reflective mirrors 315 and 31
However, in FIG. 3, the reflection mirrors 315 and 316 are not shown for convenience, and the light passes through the r/θ lens 314 and is guided to the photoreceptor 310.
The photoreceptor 301 is shown as being directly irradiated with a laser beam.

Here, the configuration of the reflecting mirror 345 will be explained with reference to FIG. 42. As shown in the figure, this anti-reflection mirror 345 is attached to a support member 456 located outside the beam incidence area with a screw 455 via a plate spring 454, and a fine adjustment screw 457 is attached to the bottom of the plate spring 454.
is provided so that the angle of the reflecting mirror 345 can be changed.

The laser scanner unit shown in FIGS. 3 and 42 is shielded from the outside as shown in FIG. 2 to prevent the scanning beam from leaking.
There is. The results of beam detection by the beam detector 346 are displayed at appropriate positions on the scanning panel shown in FIG.

FIG. 4 is an explanatory diagram of the registration roller front pass sensor 394. Manual stop switch 3 in Figure 2
28 only detects manually fed paper, whereas the purpose of the registration roller front path sensor 394 is to detect paper during paper feeding from a cassette. In FIG. 4, the paper fed from the upper cassette 317 and the lower cassette 321 by either the upper paper feed roller 318 or the lower paper feed roller 322 is cured by the paper guide plate and fed to the registration rollers 329. be done. At this time, if paper feeding is performed correctly, the light emitted from the light emitting diode 393 is blocked by the paper and passes through the pass sensor-It-3 in front of the registration roller.
The fed paper can be confirmed by not allowing light to enter the paper 94. Also, if the paper is not fed correctly, the paper
Since it does not reach the position of the registration roller front pass sensor, the register [~[]-ra front bus sensor is
Since the light emitting diode 3'93 continues to receive light, it can be recognized that the paper has not been fed.

FIG. 5 shows a reversing tray 381 which is an optional unit.
FIG. Normally, the printer 300 is equipped with a non-reversible tray 397 as shown in FIG.

When using such a non-inverted type, the first printing paper is -
Since the data is on the sliding side, the data must be sent from the last page from the information providing device (host system 1), which has the disadvantage that the information file method in the host system 1 becomes complicated. . Therefore, the book reversing tray 381 is indispensable in order to compensate for the above-mentioned drawbacks.

In FIG. 5, the paper that has passed the paper ejection roller 335 of the printer 300 is transported by the transport rollers 382 and 383.
The sheet is stored in the tray 384 in an inverted form from when it passes the sheet discharge roller 335.

Therefore, since the printing side of the paper is on the bottom side, the first page is on the bottom side, but if you take out the paper from the tray 384 and turn the printing side of the paper on the front side, the first page will be on the top side and the last page will be on the bottom side. The page is on the lower side, and the above-mentioned drawbacks of the non-reversible tray 397 can be solved. In the figure, reference numeral 385 denotes a paper hemper, which can be slid according to the length of the print paper in the transport direction. 388 is a paper holding actuator for preventing the paper stored in the 1-lay from floating; 395
391 is a light emitting diode for confirming whether there is paper in the tray 384; 392 is a tray sensor on the light receiving side; When the paper 390 is in the tray 384, the tray sensor 392 is not exposed to light;
When there is no paper 390, the presence or absence of the paper 390 can be detected by shining light on the ray sensor 1 to 392.

The other side of the paper presence/absence and paper full detection section is shown in FIG. This causes the actuator 38 to rotate around the pivot point 386.
8 is provided, and a lever 398 is provided in series above,
The tip of the lever 398 is connected to the solenoid 38 which is a separating means.
9 and a coil 387 serving as a release means, the lever 398 is moved in one direction depending on the state in which paper is stored in the paper storage section 390, and the state at this time is detected by a detection means such as a plurality of sensors 401, 402 is used for detection. In the various states of actuator 388, position 81 indicates "1 paper full" and position a2 indicates "paper present".
, the position a3 becomes "out of paper". The separating means 389 separates the actuator 388 at least while the paper 390 is being ejected into the paper ejection tray 384, and synchronizes with the current state signal when the paper should be detected, for example, during a printing operation or during a stop. C, the solenoid 389 is turned off and the actuator 388 is released.
detection operation is performed. Therefore, the discharging leading end of the paper 390 does not collide with the actuator 388, and the discharging operation is not hindered.

Note that the paper sent into the paper ejection tray is detected by the paper ejection switch 395 at one sheet f0, and the contents are counted by a paper ejection memory counter (RAM 107 in FIG. 13), which will be described later, to detect the number of sheets. And one rough cup.”
When this happens, it is displayed on the 1 to Rayful lamps 358 in FIG. 6, and the memory counter is cleared.

FIG. M6 is a detailed diagram of the operation panel of the printer 300.

In FIG. 6, 350 is a top cover of the printer 300, 351 is a front cover, and 352 is a maintenance cover. Open it in the direction and process. The maintenance cover 352 has a structure that can be opened from the top, but the front cover 351 cannot be opened unless the front cover 351 is in the dark 1=state in the direction of the arrow to prevent operator's erroneous operation. ing.

353 is a 6-digit mechanical counter, which is incremented by 1 each time a sheet of paper is printed. 354 is a select switch for selecting online/offline, and 355 is a select lamp that corresponds to the select switch 354 and lights up when online.

356 is a 1-digit seven-segment LED that displays the error details when a serviceman is called, the mode number when in maintenance mode, etc., and 357 is the printer 30.
A power lamp that indicates that the power is turned on.
Reference numeral 358 indicates a tray full lamp that indicates that the reversible tray unit 381 is full of printing paper, and reference numeral 359 indicates a color LCD display that displays details of the operating status of the printer. Total Karan 3 explained so far
53 to LCD display 359 are constantly operated or displayed. Next, the maintenance cover 352
This section explains the parts that cannot be operated without opening the . The following parts are to be operated only by service personnel.

403 is a maintenance switch for selecting maintenance mode and replacement mode; 406 is an indicator lamp indicating that the device is in maintenance mode.

407 is an indicator lamp indicating that there is a replacement t-tod status;
404 is a selection switch that selects the operation mode number in each mode; 408 is a selection lamp that indicates that the selection operation by the selection switch 404 is possible; 405 is a test print mode selection and the above-mentioned maintenance, replacement, and test print. 360 is a main exposure adjustment volume which will be described later, and 361 is a shadow exposure adjustment volume. Further, both volumes 360 and 361 have a structure in which an adjustment screwdriver is inserted and turned, and cannot be turned by hand with the maintenance cover 352 open.

FIG. 7 is a detailed diagram of the LCD display 359, and the function of each display segment will be explained below.

371.372 is a segment indicating the standby, ready state, etc. of the printer 300. When waiting until the fixing unit is ready, both 371 and 372 are lit, in the ready state, only 371 is lit, and during printing operation, both 371 and 372 are turned off. .

373 blinks when a jam occurs in the paper feeding section, and the segment indicating the paper feeding status also blinks at the same time.

That is, the manual feed designation 365 blinks in the manual feed mode, the upper cassette 364 blinks in the upper cassette mode, and the lower cassette 363 blinks in the lower force pit mode.

374 blinks if there is a jam in the conveyance system (registration roller 329 or later). At this time, the paper feed segment also blinks at the same time, as in the case of a paper feed jam. 375 blinks when the toner pack (not shown) is full of toner collected by the cleaning blade 310 in FIG. 376 blinks when the toner hopper (not shown) of the developing device 307 runs out of toner. 377 and 378 blink when a serviceman error, which will be described later, occurs. 379
blinks when an operator call, which will be described later, occurs.

380 blinks if there is no paper in the selected cassette. 362 displays the size of the selected paper.

For example, if the upper cassette side is selected and the paper cassette is A4 vertical, A4-R lights up, and if 86 is selected in the manual feed mode, 80 lights up. 363 is lit when the lower cassette is selected, 364 is lit when the upper cassette is selected, and 365 is lit when manual feed is selected. 366 is printer 30
It represents the shape of 0 and is always lit, 367 is the photoreceptor 30
1, which is always on; 36B, which represents the top shape of the printer 300, is always on, except when the conveyance section is jammed; and 369, when the conveyance section is jammed (when 374 is blinking), the above-mentioned 368 is lit alternately. Reference numeral 370 indicates five segments that display the conveyance state of the paper, and one segment moves from the right side to the left side while lighting up.

FIG. 8 is a schematic block diagram of the data control section 2 in FIG. 1. The data control unit 2 converts the character code information and image information sent from the host system 1 into a dot-compatible page memory 20 that corresponds to the print area on the paper of the printer 300 and then stores the data. Further, the stored data on the page memory 20 is sent to the printer 300 to perform a printing operation.

The data latch 2 is configured to accept two types of information. In other words, one is character code information (JIS8
In this case, the character generator 15 generates a character pattern corresponding to the character code, and stores the dot information of the character pattern on the page memory 20. The other is image information, and in this case, it is already input in the form of dot information, so it is stored in the page memory 20 as is. Hereinafter, an overview of the data control section 2 will be explained with reference to FIG.

Information from the host system 1 is sent to the interface 50 via the signal line s01, and the information is further stored in the data latch 3.

Signal line 8 between interface 50 and host system 1
02 is sent from the host system 1. The data strobe signal and other control signal line S03 are a low signal and status signal line from the data control device.

The format of the information sent from the host system 1 is shown in FIG. 9 and FIGS. 1 and 0. The format example in Figure 9 is for character code information, where a character identification code indicating that it is character code information and a paper size code indicating the size of the paper to be printed are placed at the beginning of one page. There is.

Thereafter, character code data is entered in the order of the first line, second line, . . . nth line, and finally an END code indicating the end of data for that page. Further, character code data for one line is made up of a code indicating the character size, a character code, and an LF code indicating the delimitation of one line of data.

FIG. 10 shows a format for image information, in which an image identification code indicating image information and a paper size identification code indicating the size of paper to be printed are entered at the beginning of one page of data. After that, 1 line.

2 lines... Image data is contained in the order of m lines. Furthermore, since the data for one line is specified by the paper size identification data, it is automatically determined by counting the specified data on the data control unit 2 side. There is.

The input information from the distributor 4 is processed as follows. The information that has entered the distributor 4 is always input from the distributor 4 to the decoder 5 via the output line S04. First, regarding the case of character code information, when the character identification code shown in FIG. 9 is input to the decoder 5, the output of the decoder 5 is input to the main control section 6 via the signal line S05. The main control unit 6 determines that the input information is character code information, and instructs the distributor 4 to input the next paper size data to the page code buffer 7 control circuit 7 via a signal line 806. . Therefore, the paper size data is input from the distributor 4 to the page code buffer 7 control circuit via the data line 807. The next 1st line, 2nd line......n
The data up to the row is input from the distributor 4 to the page code buffer via the data line 808. This cut character code data is stored in a memory area on page code buffer 9 designated by address counter 8. When the input of one page's worth of characters into the page code buffer 7 is completed and the END code shown in FIG. 9 is detected by the decoder 5, the main control unit 6. EN for each page code buffer 1 control circuit 7
Inform D code detection. When the page buffer control circuit 7 confirms through the signal line 809 that input of character codes for one page into the page code buffer is completed, the data is stored in the page memory 20 in units of dots.

FIG. 11 shows the correspondence between memory spaces on the page memory 20 and sheets. In FIG. 11, broken lines indicate the outside of each sheet. In other words, 25 is the leading edge of the paper (common to all sizes), 2
4 is the left edge of the paper (common to all sizes), 28 is the right edge of A5 size paper, 27 is the right edge of A4 size paper, 26 is the right edge of A3 size paper, 31 is the rear edge of A5 size paper, 30 is the right edge of A4 size paper The trailing edge 29 indicates the trailing edge of A3 size paper. 32 is the address ADR (0) of the read address counter 19 and the write address counter 18.
, 0> points. Here, ADR (0, O) indicates that both the vertical address (ADRV) and the horizontal address (ADRH) are 0'. In other words,
The write address counter 18 and the read address counter 19 are configured to input vertical addresses (
ADRV) and a horizontal address (ADRH), ADRV represents a vertical address (arrow b in Figure 11), and ADRH represents a horizontal address (arrow C in Figure 11).

43 is the last horizontal address of A3 size paper (A3HE
), 44 is the horizontal address of A4 size paper (A4HE)
, 45 is the horizontal address (A5HE) of A5 size paper. Similarly, 46 is the last vertical address of A3 size paper (A3VE), 47 is the vertical address of A4 size (A4VE), and 48 is the vertical address of A5 size paper (A5
VE). 33 is A size vertical address ADR
V-○, point A of horizontal address ADRH=A3HE
DR(0, A3HE), 34 is similarly ADR(0,
A4HE), 35 indicates ADR(0, A31-I E ), respectively. 36 is A3 size vertical address A
DRV= (A3VE), horizontal address A D RH=
O's point ADR (A3VE.

0) and 37 are similarly ADR (A4VE, O).

38 indicates ADR (A5VE, O), respectively.

39 is the A3 size vertical address ADRV=A3VE,
Horizontal 7F less ADRH = A38E point ADR (A
3VE, A38E), similarly 40 is ADR (A4
VE, A4HE), 41 is ADR (A5VE, A38
E) are shown respectively.

Storing a character pattern as a dot image in the page memory 20 having the above-mentioned memory space is performed as follows. The character size data of the first line is sent from the page code buffer 9 via the signal line S10 to the page]-de buffer 7
It is read by the control circuit 7. The character size types in this embodiment are basically two types of fonts: 40x40° and 32x32 dots, and the page code buffer 7 control circuit 7 determines the character size based on the read character size code and sends the determination signal. It is sent to the page memory control circuit 17 via a signal line 811 and to the character generator 15 via a signal line 813, respectively. Page memory control circuit 17
Then, the line feed bit and character pitch are controlled by the character generator 1 based on the character size determination signal.
In step 5, character size areas are switched.

Character codes after the character size data are stored in a line address counter 11 in a line buffer 10 with memory capacity for one line.
will be transferred to the specified area.

When the transfer of one line of character code data to the line buffer 10 is completed, the line address counter 11 returns to the initial address (
Return to 0). First, the first vertical line of the character font (line 57 in FIG. 11) is written into the page memory 20.

Here, the line/scan counter 13 has an initial value (0,
0>, and write address counter 18
The value of is ADR (0, 0>. Row buffer 10
The character code data is sequentially read out in a constant cycle starting from the first digit, and is latched in the output latch 12 in order to synchronize with the line counter 13. When the first character code (°T' character in this embodiment) is latched by the output latch 12, that character code and the output of the line/scan counter 13 are combined in the synthesis circuit 14, and the character generator 15 generates a character pattern selection code. is input to the character generator 15 as follows. Here, the configuration of the line/scan counter 13 will be explained.
The upper 6 bits are a counter that counts scanning lines, that is, a counter in the vertical direction of the character pattern.
In the case of a 40x40 dot character, 0 to 39 plus, line feed pitch control counts 912 minutes and returns to 0'.

The lower 3 bits serve as a counter in the horizontal direction of the character pattern, and in the case of a 40x40 dot font, it counts from 0 to 4 plus the character pitch control and returns to 101 (because the output of the character generator 15 is 8-bit parallel). be).

Below, the font size is 40X40. The operation in the case where the horizontal distance between characters is 8 bits and the vertical distance between two characters is 8 bits will be described. As mentioned above, the first character hood ('
T') is set in the output latch 12, the character code and the output of the line/scan counter 13 are combined in the synthesis circuit 14, and the character generator 15 outputs the code as a character pattern selection code for the character generator 15.
is input. At this time, since the value of the line/scan counter is (0, 0), the character generator 15 outputs the data (8 bits) of the 101st vertical line and 101st horizontal line of the character pattern. Ru. The output data of the character generator 15 is sent to the output latch 1 in order to synchronize writing to the page memory 20.
-H is latched at 6 and written to the address on the page memory 20 designated by the write address counter 18 by the page memory control circuit 17. In this case, since the value of the write address counter 18 is ADR (0, O), it is written to the vertical address 'O' and the horizontal address 'Ol.Then, the writing of a 1-byte character pattern is When finished, the value of the line/scan counter will be (0, 1
), and the value of the write address counter 18 also changes to A.
Changes to DR(0,1). Therefore, the character generator 15 outputs the data of the "0" line in the vertical direction and the "1" line in the horizontal direction of the character pattern, which is latched into the output latch 16 as described above, and then stored in the page memory 20.
ADR (written to address 0, 1>). In this way,
The end of the vertical “0” line of one character pattern (“
When writing of data (4'th data) is completed, the value of the line/scan counter becomes (0, 5), and the write address counter 18 becomes ADR (0, 5>).The horizontal spacing between characters is Since it is 8 dots (1 byte),
All outputs of the character generator 15 are forced to 0' by a command from the page code buffer 1 control circuit 7.
0' is written to the ADH (0, 5) address of the page memory 20, and after the write operation is completed, the row address counter is incremented by 1' and the next character code is transferred from the row buffer 10 to the output latch 12. Set. Further, the line/scan column is (0,0), and the I address counter 18 is ADH (0,6). Therefore, next is the page memory 2 of the data of the 0'th line in the vertical direction of the character pattern O'.
A write operation to 0 is performed. At this time, the write address counter 18 is ADR (0, 6), (0, 7>, (0, 8).
), (0°9), and (0, A), and the character pattern data of O is written to the address specified by the writing address counter 18, respectively.

Then, the value of the write address counter 18 is (0°B),
When the value of the line/scan counter 13 becomes (0°5), 0' is written to the page memory 20 in the same way as described above, and after the write operation is completed, the row address counter becomes plus 1.
', and the next character code is set in the output latch 12 from the line buffer 10.

Further, the line/scan counter 13 becomes (0°0), and the write address counter 18 becomes ADR (0°C).

In this way, the character pattern data of the ``0'' line in the vertical direction is sequentially written into the page memory 20.
When the 'LF' code is output to the output of the line buffer 10, the '[F' code detection signal is transmitted to the page code buffer control circuit 7 through the output line 814, and the writing operation of the character pattern from the character generator 15 is performed. Stop. From then on, the write address counter 18 is sequentially incremented by 1' and 0' is forcibly written to the page memory 20.Then, the value of the write address counter 18 indicates that A3 size is currently specified. Iruto ADR
When the value of (0, A3HE), that is, the 33rd point in FIG.
1.18(0), line/scan counter 13 is (1
, O), respectively. And output latch 1
2 is the character code of the first character from line buffer 10 “
T' is set again. Then, the character pattern data of the ``1'' vertical line of the character pattern is stored in the page memory 2.
Written to 0. Similarly, the vertical direction ``2'' of the character pattern.

3'... When the write operation up to the 39th line is completed, the write address counter 18 goes to DR (28, 0).
, the row address counter 11 is (O).

The line/scan counters 13 are set to (28, 0), respectively. This completes the writing operation of character pattern data for one line, but since the line feed pitch is every 48 lines, O' is forcibly written into the page memory 20 for the remaining eight lines. When the writing of O' for 8 lines is completed, the address value of the writing address counter 18 is changed to the point 61 in FIG. 11, that is, ADR (
30, O), the row address counter 11 is (0).

The line/scan counters are each set to initial values (0, 0). This completes all write operations including the line feed pitch for one line. and row buffer 10
The next second line of character code data is transferred from the page code buffer 79. When the transfer of character code data is completed, the row address counter 11 returns to the initial address (0). Thereafter, character pattern data on the second line is written in the same manner as writing the character pattern data on the first line. Therefore, when all writing operations for the character pattern data on the second line are completed, the address value of the write address counter is ADR(60,0>, and the row address counter 11 is (60,0>).
0), and the line/scan counters are set to (0, O), respectively. In this way, the character codes of each line are sequentially patterned and the pattern data is written onto the page memory 20. Then, when an "END" code indicating the last line is detected from the line buffer, the data writing operation of the character pattern is stopped.Then, the page code buffer 7
The control circuit 7 forcibly sets the output of the character generator 15 to 0' via the signal line S13, and also notifies the page memory control circuit 17 that writing of character pattern data has ended.

After receiving the write end signal, the page memory control circuit 17 selects the final memory address (39 point ADR (A3VE) in FIG. , A3
Forcibly write 0' to HE)). And Figure 11 3
0' is written to the 9th point, and the entire operation of writing character pattern data for one page of the specified paper size to the page memory 20 is completed. And write address counter 1
8 is ADH (0, O), row address counter 11 is (
O), the line/scan counters 13 are all initialized to (0, O).

Next, a case where the data sent from the host system 1 is image information will be described. When the image identification code shown in FIG. 10 is input to the decoder 5, the output of the decoder 5 is input to the main control section 6 via the signal line 805. Main control section 6
Then, it is determined that the input information is image information, and the signal line 806 instructs the distributor 4 to input the next paper size data to the page memory control circuit 17.

Therefore, the paper size data is sent from the distributor 4 to the data line 807.
The data is input to the page memory control circuit 17 via the page memory control circuit 17. Next image data 1, 2. ...The image data up to m is sent from the distributor 4 to the page memory 20 via the data line 815.
is input. The method of inputting image data to the page memory 20 is performed as follows. When the page memory control circuit receives the paper size identification code, it stores the next image data at 32 points (address ADR (0, 0)) in FIG.
The write address counter 18 is set to ADH (
0,0). Then, the data length for one line in the horizontal direction is determined from the paper size identification code by referring to a table in the page memory control circuit 17. Therefore, if the paper size of the image information to be input into the page memory 20 from now on is A4, the data length of one line will be a value up to 44 points (A4HE) in FIG. 11, that is, A48E'. Naturally, the length of the image information per line sent from the host system 1 is Δ4HE.
' Therefore, image data 11 image data 2 in FIG. ...The image data conscription data length is “A4VE”
The number m of image data is the value of 47 points in FIG. 11, that is, A4VE'. Therefore, the image data 1 in FIG. 10 is stored in the page memory 20 as shown in FIG.
2 points ADR (0,0) to 34 points ADR (0
゜A4HE), image data 2 is a 51 point line,
Image data 3 is a 52-point line... Image data is a 37-point line, so the final address is 40 points ADR (A4VE, A4) IE).

While controlling the write address counter 18 in this way,
Write image information to page memory 20.

The character pattern data 13 written in the page memory 20 in this manner is sequentially outputted to the latch 21 . Gate circuit 23. Data to be printed is sent to the print control section through the interface 22 and the interface bus S17. In FIG. 8, 817 is a status data line from the print control unit, 818 is a command data line for specifying the operation mode, etc. to the print control unit, S19 and S20 are strobe signal lines when sending command data and print data,
S21 is a busy signal line from the print control unit, S22 is
826 is a horizontal synchronization signal line from the print control section, S23 is a page end signal line that also indicates the end of print data, S24 is a ready signal line of the print control section, S25 is a print request signal line that indicates a printable state. a select signal 11 (2 lines) specifying the data content of the data lines in the interface bus 817;

Reference numeral 827 is a print start signal line that instructs the print control section to start a print operation.

To explain in more detail when data is sent to the print control unit, printing from the data control unit 2 is started via the start signal line 827.
In contrast, the print control section sends a horizontal synchronization signal 822.

This horizontal synchronizing signal 822 first sequentially sends out each data of the 32-point line in FIG. S2
2, the address is sequentially changed line by line according to the page end signal 823 from the print control unit.
This operation is repeated until the page end signal S23 is received, and the data in the designated area of the page memory 20 is sent to the print control unit.When the page end signal S23 is received, the data sending is forcibly stopped. In the print control section, the page end signal 823 is output at the same timing as the horizontal synchronization signal 822. Also, in correspondence with the memory addresses in Figure 11, the last line A3 of the memory area of the paper size has 46 points, and A4 has 47 points.
The print control unit outputs the print at the same timing as the point or before the point.

Further, in the page memory control circuit 17, the page memory 20
When the sending of print data starts, the values of the read address counter 19 and the write address counter 18 are always compared, and if the value of the read address counter 19 is larger, the sending of that data is finished. control is performed to permit write operations to the memory area that has been accessed. Therefore, the loss of writing time to the page memory 20 is greatly reduced.

FIG. 13 shows a block diagram of the print control section 100 in FIG. 1. In FIG. 13, 101 is the print control section 100.
A microprocessor 1102 for controlling each unit in the microprocessor 1102 is an interrupt control circuit for controlling interrupts to the microprocessor 101, and command signal lines S30. Page end signal 11829 from print data write control circuit 19.
Timeout signal ll528 from general-purpose timer 103
The interrupt request signals from each of the microprocessor
Call 101. A general-purpose timer 103 generates basic timing signals for controlling paper conveyance, drum rotation processes, and the like. This general-purpose timer 103 is set to 10m5ec in this embodiment. A ROM (read only memory) 104 contains all control programs for operating the print control section 100. 1
05 is the same <ROM and contains a data table different from that of the ROM 104. The contents of the data table are shown in FIG. 45(A). In FIG. 45(A), addresses (4000, 4001) contain top margin control data for paper size A3.

Addresses (4002, 4003) are bottom margin control data, addresses (4004, 4005) are left margin control data, and addresses (4006, 4005) are data for left margin control.
07) each has write margin control data. Similarly, addresses (4008 to 400F>) contain data for controlling the top, bottom, left, and right margins for paper size B4.The following margins correspond to various paper sizes up to address (4087). Contains control data.These margin control data are sent to the print data write control circuit 1, which will be described later.
It is used as set data for the margin control counter in 19.

Addresses (4100 to 41 FF>) contain a table of command codes for specifying operations from the data control unit 2, and are used to check command codes from the data control unit 2. /Bottom margin change table.

These include a top margin adjustment table, a cassette upper/lower adjustment table, a cassette/manual feed adjustment table, etc. Addresses (4200 to 42FF) contain data on the charging characteristics of the photosensitive drum 301, including five types of data A to F. This data is then used for temperature correction control of the charging charger 304, which will be described later. Addresses (4300 to 43FF) are an exchange data table, and photosensitive drum 301. It contains replacement cycle data for the developer in the developing device 307 and the fixing roller 332.

The addresses (4400 to 47FF>) are a control timer table that contains various timer values for performing printing operations, such as each process timing and paper feed timing.

106 is a RAM (random access memory), which is a working memory, and includes a timer (TIM>A) as shown in FIG.

Contains a paper size register B, . . . , E1 (stores cassette size data based on signals from cassette size detection switches 320 and 324, which will be described later), status register 6, and other contents. The microphone processor 101 compares the cassette size stored in the paper size register with the size of recording information (image data, etc.) from an external device sent from the data control unit 2, and determines which size is the cassette size. If the value is large, the printing control section 100 in the subsequent stage
It is designed to issue printing operation commands to the printer. Therefore, it is possible to print even if the printing paper is larger than the size of the information sent from the outside, and the usability can be improved. Reference numeral 107 denotes a non-volatile RAM, and the data in the memory is retained even when the power is cut off.The data contents in the non-volatile RAM are shown in FIG. 45(B). In FIG. 45(B), the address (6000) contains the drum characteristic number input from the operation unit in the exchange mode, and the address (6100) contains the jam information at the time of jam occurrence. It is used to prevent forgetting to dispose of jammed paper inside the machine when the power is turned off. address(
Reference numeral 6200) is a paper discharge tray counter that counts the sheets in the reversing tray 381, and is incremented by 1 each time one sheet of paper is sent to the reversing tray 381. When this count value reaches a predetermined value, the tray becomes full and a message is displayed on the operation unit to prompt the operator to take out the paper from the tray. Further, the main paper discharge tray counter is automatically cleared when paper is removed from the tray by the operator. Therefore, even if the power is turned off, the number of sheets remaining in the tray is maintained by the book counter.

Address (6300) is a drum exchange counter, which counts up by 1 for each print. When the value of this counter reaches the value of the replacement table (drum) shown in FIG. 45(A), the operator is informed by the display on the operation section that the drum should be replaced.

Address (6400) is a carrier exchange counter, which is incremented by 1 for each print as in the case of drum exchange, and the value of this counter reaches the value of the exchange table (developer) shown in FIG. 45(A). Displayed on the operation panel when

Address (6500) is a fusing port-ra exchange counter, which is counted up by 1 for each print as in the case of drum replacement, and when it reaches the value in the replacement table (fusing port-ra) in FIG. 45(A), it is operated. section.

108 is a power supply sequence circuit, and the non-volatile generation RA
It has the function of preventing erroneous operation when turning on or turning off the power of M107. 399 is a power supply device that supplies power to the control section. Reference numeral 110 denotes an input/output port that outputs display data to the operation display section 111 and reads data on each operation switch. Reference numeral 112 denotes an input port for reading input data from each detector 113 in the print control section 100. 116 is a motor, high voltage power lamp, solenoid,
Drive elements such as fans and heaters are shown. 115 is a drive circuit for the drive element 116; 114 is a drive circuit for the drive circuit 1;
This is an output port that provides an output signal to 15. 312 is a laser scan motor for operating the laser beam, 118 is a drive circuit thereof, and 117 is an input/output port that provides a drive control signal to the drive circuit.

344 is a semiconductor laser, 120 is a laser modulation circuit that performs optical modulation of the semiconductor laser, and 346 is a beam detector that detects the light beam operated by the laser scan motor, and a PIN diode that responds at high speed is used. There is.

121 is a high-speed comparator for digitizing the analog signal from the beam detector and creating a horizontal synchronization pulse; 119 is a high-speed comparator for digitizing the analog signal from the beam detector; This is a print data write control circuit that performs write control and generation of test pattern print data. 122 outputs status data to the data control unit 2;
This is an interface circuit that controls the reception of command data and print data from the printer.

The details of the main blocks in FIG. 13 will be explained below. Figure 14 shows various detectors 11 in Figure 13.
FIG. 3 is a detailed circuit diagram of No. 3. In FIG. 14, signals from various detectors are input to a multiplexer 139. In multiple playback, an 8-pit signal S32 is input to the input port 112 in FIG. 13 by a select signal S31.

Reference numeral 320 denotes an upper cassette size detection switch, which is composed of four switches, and the combination of these switches indicates the paper size. Reference numeral 324 denotes a lower cassette size detection switch, which has the same configuration as the upper cullet size detection switch. Reference numeral 319 is a cassette upper paper out switch, which is turned on when the cassette runs out of paper. 323 is a lower paperless switch. 123 is a pass sensor in front of the registration roller, and a CDS light receiving element is used. In this sensor, a bias voltage is applied through a resistor (not shown), and the output voltage changes depending on the presence or absence of paper. Therefore, by manually inputting the output to the comparator 124 to which the reference voltage vre[1 is applied, a signal for determining the presence or absence of paper can be obtained.

Reference numeral 326 indicates a manual feed switch for detecting paper from the manual feed guide 325, 336 indicates a paper ejection switch located on the fixing roller section, and 395 indicates a paper ejection switch located on the paper ejection tray section. Reference numeral 125 indicates a toner out detection switch that detects the absence of toner in the toner box, and 126 indicates a toner full detection switch that operates when the toner pack is full of toner.

Reference numeral 127 is a sensor for detecting the specific toner concentration of the developer (probe concentration detection sensor), and a photodiode is used. A bias voltage is applied to this sensor via a resistor, and the output voltage changes depending on the toner concentration. Therefore, by inputting the output to the comparator 128, since the reference voltage ref2 is applied to the other input terminal of the comparator 128, a signal of 1 or 0 is obtained when the toner concentration is above or below the specified value, respectively.

129 is 0N10FF by opening and closing the front cover.
130 is a temperature fuse provided in the fixing device, 131 is a door switch that turns the drive power (+24VB) to 0.
This is an MC relay that turns N10FF. Since one of the temperature fuses 130 is connected to the power supply +24VA,
When the temperature fuse 130 is blown due to an abnormality in the fixing device, the MC relay 131 is turned off and the driving power is turned off.
F is given. Further, the temperature fuse 130 is connected to a resistor RO1, and one side of the resistor ROI is connected to a resistor RO2 and an input of a comparator 132. Further, a reference voltage Vref3 is applied to the other input of the comparator 132. Therefore, when the temperature fuse 130 blows, the input to the comparator 132 becomes O■. Therefore, the comparator 132 outputs a temperature fuse blowout detection signal. Reference numeral 133 denotes a destination selector switch. Specifically, this switch is set to 0N10FF, so that the ON state is for domestic destinations (A and B sizes), and the OFF state is for U.S. destinations (legal and letter size). Therefore, for example, even if the combination of hoods set by the upper or lower cassette size switches (4 pieces) is the same, depending on the state of this switch,
Select one of the paper sizes for the US.

134 is a jam reset switch, which is installed inside the front cover. This switch is a switch that is turned ON for confirmation after the operator calls for a paper jam or full toner, after the operator clears the jam or replaces the toner bag. Therefore, unless this switch is turned ON after the above processing, the jam or full toner display on the operation panel will not be cleared. Reference numeral 392 is a paper discharge tray sensor for detecting paper in the tray shown in FIG. A thermistor 334 detects the temperature of the fixing device, and is controlled so that the temperature detected by this thermistor is constant. Thermistor 33
The output of 4 is connected to the resistor RO3 and the input side of comparators 136 and 137. Therefore, the input voltage of the comparator changes as the resistance value of the thermistor 334 changes due to humidity.

That is, as the temperature increases, the input voltage increases.

The other input terminal of the comparator 136 has a resistor RO6
A voltage divided by RO7 is applied, and the output of the comparator 136 changes depending on whether it is higher or lower than the divided reference voltage. Also, resistors RO6 and R
A resistor RO8 is connected to the connection point of O7, and one end of the resistor RO8 is connected to the collector of the transistor 138. Therefore, when this transistor 138 is turned ON by the input signal (power save signal LS3), the comparator 136
The reference voltage of is lowered by resistor RO8, and the temperature control of the fuser is lower than when transistor 138 is OFF. Therefore, the power consumption of the fixing device becomes low and the fixing device enters a power save state. Furthermore, the reference voltage of the amparator 137 is given by the voltage division of the resistors RO4 and RO5. Since the reference voltage of the comparator 137 is set much lower than the reference voltage of the comparator 136, it is possible to detect a temperature drop in the fixing unit due to heater disconnection or heater drive circuit failure during printer operation. can. And output 8 of comparator 1, 36
33 is input to the multiplexer 139 on one side and read by the microprocessor 101. Note that this input signal is used to detect the ready state of the fixing device. The other signal is used as a drive signal for the fixing device heater lamp 333 in FIG.

342 is a drum temperature sensor that detects the temperature near the photoreceptor 301. The output side of thermistor 342 is connected to resistor R58 and the input of operational amplifier 270. Therefore, the resistance value of the thermistor 342 also changes depending on the temperature change near the photoreceptor 301. Therefore, operational amplifier 2
The input voltage of 70 also changes. The operational amplifier 270 outputs a low voltage when the temperature of the photoreceptor 301 is low, and a high voltage when the temperature is high. operational amplifier 2
70 is a voltage follower, and its output is
It is connected to the input of the A/D converter 271. Then, the output voltage of the operational amplifier 270 is converted into a digital value by the A/D converter 271 and read by the microprocessor 101 through the multiplexer 139. This A/D converted temperature data of the photoreceptor 301 is used for charge correction of the photoreceptor 301, which will be described later. 440
441 is a cassette/manual feeding adjustment switch, and 442 is a top margin adjustment switch.

FIG. 15 is a detailed block diagram of the drive circuit 115 and output element 116 in FIG. 13. In FIG. 15, 141 is a developer motor, and a DC-driven Hall motor is used. Reference numeral 140 is a driver for the developer motor, which performs PLL control. 143 is a fixing device motor, and a DC-driven Hall motor is used.

142 is a driver for the fuser motor 143;
Performs PLL control. 145 is a fan motor for cooling the inside of the machine, and a DC-driven Hall motor is used. 144 is a driver for the cooling fan motor, which is a PLL like the developer and fuser driver described above.
No speed control is performed. 147 is the photosensitive drum 30
1 drive motor, and uses a 4-phase pulse motor. 146 is a driver for the drum motor 147, which employs a constant current 1-2 phase excitation method. The speed is approximately 1200 PPS, which is the speed at which vibrations are less likely to occur. 149 is a registration motor that drives the registration roller 329 and manual feed roller 327, and is a pulse motor. 148 is a driver for the registration motor, which uses a constant voltage two-phase excitation system. The speed is 40
It is about 0 PPS.

Note that when the registration motor 149 rotates in the normal direction, the registration roller 329 rotates, and when the rotation direction is reversed, the manual feed roller 327 rotates. These are transmitted via a one-way clutch.

151 is a lower paper feed roller 322 and an upper paper feed roller 3
The paper feed motor that drives 18 is a pulse motor. As above, pressure and reverse rotation are transmitted via a one-way clutch. Reference numeral 150 denotes a driver for the paper feed motor 151, which uses constant voltage two-phase excitation similarly to the registration motor driver 148. The speed is about 400PPS.

Reference numeral 302 denotes a static elimination lamp that removes residual charges on the photoreceptor 301 before charging, and is composed of a plurality of red LEDs. R10 is a current control resistor for the static elimination lamp 302, and 152 is a driver for the static elimination lamp 302. 303 is a pre-transfer static elimination lamp placed in front of the transfer charger to increase transfer efficiency, and includes a plurality of red LE'
It is composed of D. R11 is a current control resistor for the pre-transfer static elimination lamp, and 153 is a driver for the pre-transfer defrosting lamp. 158 is a solenoid for the toner collection blade, and when this solenoid is turned on, the photoconductor 30
1 is pressed against the blade 310. 154 is a driver for the blade solenoid 158. Reference numeral 159 denotes a toner replenishment motor for replenishing toner from the toner hopper to the developing device 307. When this toner replenishing motor rotates, the toner is supplied from the small toner collar to the developing device 307.
Replenish toner. The operation of the toner supply motor 159 is performed according to the output of the prologue concentration detection sensor shown in FIG. 14. 155 is the toner supply motor 15
9 driver. 131 is an MC relay that works in conjunction with the door switch similar to that shown in FIG. 14, and 156
is that driver. As shown in FIG. 15, the power supply side common for motors, lamps, etc. for which the MC relay 131 is omitted is connected to the contact 163 of the MC relay 131, and the other contact is connected to the +24VB power supply. The configuration is such that the motor and lamp can be operated when the lamp is ONL.

304 is a charger for charging, and the case of the charger is connected to the ground of the aircraft body.

The corona discharge wire of the charger is connected to the high voltage power supply 338.
is connected to the output terminal of the charging high voltage power supply 160,
An 0N10FF signal line S35 for high voltage output and an analog control signal line 836 for changing the high voltage output current are connected to the input of the high voltage power source for charging. Further, the analog control signal line 836 is connected to the D/A converter 165,
Data from the charging voltage control data line 837 from the microprocessor 101 is converted into an analog voltage by the D/A converter 165 to control the output current of the charging voltage power source. 306 is a peeler charger, and the peeler charger 306 is connected to the output of the high voltage power source 161 for peeler. The high-voltage power source for peeling has an AC output.

Reference numeral 305 is a transfer charger for transferring the developed toner on the photoreceptor 301 onto paper, and the transfer charger is connected to the output of the high-voltage power source 62 for transfer. In addition to the transfer charger output, the high-voltage transfer power source also incorporates a developer bias power source, and its output line 838 is connected to the developer magnet roller 308. This voltage applies a bias voltage to the magnet roller 308 to provide a developing bias. 33 is a heater lamp of the fixing device, and the C side is connected to one of the power supplies of AClooV.

The other end is connected to the second contact 164 of the MC relay 131, and the other end is connected to the heater drive circuit 166. Therefore, the heater lamp 333 is connected to the MC relay 1.
It operates only when 31 is ON. Also, heater drive circuit 1
Two input signals S33 and 839 are input to 66, and 833 is the thermistor 33 in the fixing unit shown in FIG.
4, which is a density control signal for the fixing device. S
39 is a forced OFF signal for the heater lamp 333 from the microprocessor-101.

Figure 16 shows the laser scan motor 3 in Figure 13.
12 and its driving circuit 118. FIG. 16th
In the figure, 312 is a circuit diagram inside the laser scan motor. 102. LO3 and LO4 indicate motor coils, and 180, 181, and 182 are Hall elements that detect the position of the motor rotor, respectively. 183,18
4.185 is a comparator for the Hall elements 180, 181.182, and its output is connected to the base of the power transistors 171, 172 and 173 which drive the motiles 102, 103 and 104 in the drive circuit 118, and resistors R26 and R27. , R28.

Furthermore, base resistors R23, R2 are connected between the bases and emitters of the power transistors 171, 172, and 173.
4 and R25 are connected to each other. As the rotor of the motor rotates, the Hall elements 180, 181, 182
are turned on in the order of 180, 181, and 182.

Therefore, the outputs of comparators 183, 184, and 185 are also 1.
The level becomes LOW in the order of 83, 184, and 185. Accordingly, the power transistors 173, 172, and 171 are turned on in this order, and driving voltages are applied in this order to LO2, LO3, and 104, thereby causing the laser beam motor 312 to rotate. Further, the output of the comparator 185 is input to the frequency division counter 175 through a waveform shaping circuit including a resistor R30, a capacitor CO6, and an inverter 174 through a diode DO2. The outputs of the output terminals Q1 and Q2 of the frequency dividing counter 175 are the outputs of the motor speed switching gate 1.
76.177, and the output of the speed switching gate is connected through an OR gate 178 to the FG input of a PLL (phase, lock, loop) control IC. Further, one input of the speed switching gate 176177 is connected to the output of the speed control signal line 840 and its inverted output. Therefore, when S40 is at the LOW level, the switching gate 177 is enabled and the output of 01 of the frequency division counter is input to the FG of the PLL control 1c167, and when S40 is at the 1-(IGH level), the switching gate 176 is enabled. , the frequency division counter 175Q2 output is P
Input to the [G input of the LL control IC 167. Here P
To briefly explain the input/output signals of the LL control IC 1670, the P/S terminal (PLAY/5TOP) stops when it is at HIGH level and starts when it is at LOW level.

1-11 In the case of G + - level, the common power of both terminals of AGC and APC is HIGI - level. FGIN is the rotation motor pulse signal input from the motor to be controlled.

N1. N2 is the signal to switch the frequency division number of the reference frequency divider inside this IC, 33/45 is the motor rotation speed switching signal, CPO
UT is a crystal reference frequency division output signal, CPIN is a reference frequency input, and LD is a lock detection signal, which outputs a HIGH level when the motor rotation speed is within the lock range, and a LOW level otherwise. AFC is the power of the motor speed control system and is the output of the 8-bit D/Al inverter inside the PLL IC, and APC is the output of the motor's phase control system.
This is the output of the 8-bit D/A converter inside C. Also P
The XOI connected to the LLIC167 is a crystal resonator for generating a reference frequency, and the COI and GO2 are capacitors for oscillation.

The output terminals of AF-C and APC of P11 control IC 167 constitute a fielding circuit with resistors R12 and R13, and are connected to operational amplifier 1.
It is connected to one side input terminal of 68. operational amplifier 16
+12V is connected to the child side input terminal of 8 through resistors R14 and R15.
A voltage divided by is applied. Further, a negative feedback circuit is formed by the resistor R16 and the capacitor CO3, and in particular, the capacitor C03 serves as a bypass filter. Therefore, the amplification degree of the operational amplifier 168 is such that it has a characteristic of attenuating inputs having a certain frequency or higher. operational amplifier 1
The output of 68 is connected to the 10 input terminal of pulse width modulation type switching regulator 10169. 169 is a commercially available pulse width modulation switching regulator I
It is C. This IC 169 and power transistor 170.
The diode DO1, coil LO1, and capacitor C05 constitute a down switching regulator circuit. In the input/output of IC169, one terminal is a comparison reference voltage terminal, and the reference voltage output terminal VREF inside 10169.
A reference voltage obtained by dividing the voltage by resistors R17 and R18 is applied. The DEADTIME terminal regulates the maximum pulse width of the output, and the VREF is connected to the resistors R19 and R19.
A voltage divided by 20 is applied. C.I., C.
2 is an output terminal, and the pulse width changes depending on the voltage value of the input terminal. That is, when the + side input terminal voltage is lower than the one side input terminal voltage, the bus width on the LOW level side of CI and C2 becomes small, and the power transistor 170 becomes
The width of N also becomes smaller.

Therefore, the voltage across the capacitor 005 also becomes smaller.

Further, when the + side input terminal voltage is higher than the one side input terminal voltage, contrary to the above, the pulse widths of CI and C2 become large, and the voltage across the capacitor 005 also becomes large.

The rotation speed control of the scan motor 312 will be explained below.

When the rotation start signal 842 of the scan motor 312 becomes LOW level, the AFC and AP of the PLL control IC 167
Since the Ryokawa voltage of C is at LOW level until the aforementioned lock signal S41 is output, the operational amplifier 168 outputs a HIGH level voltage. Therefore,
The output pulse width of the regulator IC169 becomes large, and the voltage across the capacitor CO5 becomes about +16V. Since any one of the Hall elements 180, 181, and 182 is ON at the position where the motor rotor is stopped, the Hall elements 180, 181, and 182 of the motor coils LO2, L03, and LO4 are turned on. The corresponding coil is excited and the scan motor 312 starts rotating. The scan motor 312 then speeds up its rotation. Since the speed control signal line 8400 level is now HIGH, the Q2 output of the frequency division counter 175 is
It is added to the FG input terminal of C167. Therefore, the frequency division counter 175 functions as an 8 frequency division circuit. When the frequency of the signal applied to FGIN reaches approximately 96% of the reference frequency inside P[LIC169, the lock signal LD841 becomes HIGH, and the AFC and APC output levels are not fixed at the LOW level (OV), but are set to PLLIC's internal D/A. It is switched to the output voltage of the converter. Therefore, from now on, the scan motor 312 is controlled to a constant speed by the speed control system output AFC and the phase control system output APC.

Further, in this embodiment, when a print command is not received from the data control unit 2 for a certain period of time (approximately 5 minutes), the scan motor enters a standby state and the output of the speed control line S40 is L.
Become OW level. Therefore, the frequency divider 175 divides the frequency from the previous frequency by 8 to 4, so the scan motor has a rotation speed of 4/8, that is, 1/2. This is to perform half-speed control as described above in order to prevent problems with reliability of the motor's bearings, etc., from occurring if the motor rotates at high speed for a long period of time. In this embodiment, the rotation speed is approximately 12.00 rpm during printing operation, that is, during high speed rotation, and approximately 6000 rpm during standby.
rpm.

FIG. 17 is a detailed circuit diagram of the laser modulation circuit 120 and semiconductor laser 344 in FIG. 13.

In FIG. 17, 344 is a semiconductor laser diode, which is composed of a laser diode main body 259 that emits light, and a monitoring photodiode 260 that is a light detection means for monitoring the output beam intensity from the laser diode 259. Reference numeral 257 is a high frequency transistor which is a voltage-current conversion means (or first current driving means) and performs optical modulation of the laser diode 259. Resistor R50 is a current detection resistor, 258 is a transistor which is a second current driving means for flowing a bias current to the laser diode 259, and R51 is its current limiting resistor, R
52 is a base current limiting resistor of the transistor 258. 254, 255, 256 are Leb-diodes 259
A high-speed analog switch for providing modulation to the gate (G) - IIG
When an H-level voltage is applied, the resistance between the drain (D) and source (S) becomes low, resulting in an ON state. When a LOW level voltage is applied to the gate (G), the resistance becomes high and turns off. The output power from the laser 259 has three levels in this laser printer.

The first is the output P(O
By turning on the analog switch 254 at N), the laser diode 259 becomes the output P (ON).

The second part corresponds to the black background on the paper, and is located on the photoreceptor 301.
In order to leave the electrical charge on the top as it is, the analog switch 25
By turning on the laser diode 259, the output of the laser diode 259 is turned off, that is, the output becomes P (OFF). The third is between the first output P (ON) and the second output P (OFF) 17) (
7) This is to increase the printing 11 degrees of one dot line with the output P(S)I), and the analog switch 255 is set to O.
By doing so, the laser diode 259 has the output P(SH) (the details of P(St-1) will be described later).

Resistors R42 and R43 are analog switches 254°255
．． Short circuit protection resistance when changing 0N10FF of 256, 249
, 250.251 are the analog switches 254, 25
5,256 gate drivers. CO9,010
,011 is a speed-up capacitor, R47,
R48 and R49 are the gate drivers 249 and 250
．． 251 input resistance.

246 is a 3NAND gate with three gate input dimensions.
(When becomes HIGH level, the output becomes 1-OW level, turns on the analog switch 254, and the laser diode 259 becomes the output P (ON) state. The first of the three input gates is connected to the inverter 253. The input of the inverter 253 is connected to the print data signal S47' (printing at HIGH level, not printing at LOW level).
The input of the inverter 252 is connected to a shadow signal 848 (HXG) (shadow on at level, off at LOW). The third is connected to a laser enable signal 349 (laser enable at HIGH level, laser forced OFF at LOW level). Therefore, the output of the NAND gate 246 is LO
The condition for reaching W level is the laser enable signal 849.
is HIGH, the shadow signal 848 is OW, and the print data signal 847 is OW. Next, 247 is 3NA
ND gate with all three gate inputs) -11GH
When the output reaches the LOW level, the analog switch 255 is turned on, and the laser diode 2
59 is in the output P(SH) state. The first of the three input gates is connected to the shadow signal 848, and the second is the inverted signal of the print data signal 847 to the inverter 25.
3, the third is the laser enable signal S49
are connected to each. Therefore, the conditions for the output of the NAND gate 247 to be LOW level are that the laser enable signal S49 is -11GH and the shadow signal 34 is
8 is HIGH, and the print data signal S47 is LOW. Next, 248 is a 20R gate, and when one of the two gate inputs becomes LOW level, the output becomes LOW level, turning on the analog switch 256, and turning the laser diode 259 on.
The FF state output becomes P (OFF) state.

245 is a sample-and-hold IC, which converts the output of the laser diode 259 into the shadow output P (S
H).

OG-INPLJT to AN8 is the analog voltage input to sample, SAMPLEC is the hold capacitor CO8
The connection terminal 5TROBE is a sampling strobe signal terminal and is connected to the sample strobe signal 846. Reference numeral 237 is an operational amplifier having an FET input, and constitutes a voltage foor DA circuit. DO3 is a Zener diode that regulates the output of laser diode 259 to be within the maximum rating. Also, the resistor R40 and capacitor 007 constitute an integrating circuit, and the resistor R41
is a discharge resistor that discharges the charge of the capacitor 007 at a constant rate. 236 is an analog switch whose gate (G) is connected to a buffer 244, and a sample signal 845 is input to the input of the buffer 244. 253 is a transistor for level conversion, and R39 functions as a current limiting resistor when charging the capacitor CO7. R38 is a base current limiting resistor of the transistor 235, and 234 is a comparator serving as comparison means. This comparator has a hysteresis characteristic due to the action of resistors R34 and R35.

The output voltage of the laser monitor amplifier 232 is applied to the input side of the comparator 234 through the resistor R34. 232 is an amplifier for the output of the photodiode 260 that detects the optical output from the laser diode 259, and serves as current-voltage conversion means. Resistor R32°R33, VROl is the operational amplifier 23
This is a resistor that regulates the degree of amplification. Therefore, the volume V
By changing R01, the amplifier of operational amplifier 232 can be changed. R31 is an output load resistance of the photodiode 260 in the semiconductor laser 344, and a voltage proportional to the output current of the photodiode 260 is obtained. 19 shows the relationship between the short circuit current 1s and the optical output po of the photodiode 260.

In FIG. 19, Is indicates the monitor current, and PO indicates the optical output of the laser diode 259. The output of P (ON) is approximately 6 mw, and the output of P (SH) is approximately 4 mw5P (
OFF) is set to O. Further, LA-A and LA-B represent two types of laser diode monitor characteristics. Normally, the volume VROI is adjusted so that the output voltage of the operational amplifier 232 is about 3V when the laser diode optical output is 611IW. Therefore, the characteristics of both graphs LA-A and LA-B in FIG. 19 can be adjusted by the volume VROI.

23B is a comparator for checking whether the laser diode 259 is emitting light, and the output voltage of the operational amplifier 232 is applied to the + side input. Also-
A voltage divided by resistors R36 and R37 (in this case set to 2.0V) is applied to the side.

Therefore, the laser diode 259 emits light, and its output of about 211 IW changes from LOW level to HIGH level, and a laser ready signal 843 is output. Further, a laser light amount setting voltage is applied to one input terminal of the comparator 234. The set voltage is given from either analog switch 240 or 241. That is, the analog switch 240 is turned on when the laser output P(ON> is set), and the output voltage of the voltage follower 239 is applied to one side input of the comparator 234.The input terminal of the voltage follower 239 has a first voltage. The voltage is input by being divided by the main exposure adjustment volume 360 and the resistor R45, which are variable means, and by varying the main exposure adjustment volume 360, the voltage at one terminal of the comparator 234 also changes. 241 is turned ON when the laser output P (SH) is set, and the voltage obtained by dividing the output voltage of the voltage follower 239 by the resistor R46 and the shadow exposure adjustment volume 361 which is the second voltage variable means is applied to the comparator 234. Applied to the input terminal of the voltage follower 23 mentioned above.
9, analog switches 240, 241, main exposure adjustment volume 360. Resistor R45, shadow exposure adjustment volume 361. The resistor R46 constitutes a light output setting means. Further, a circuit that compares the voltage detected by the monitor photodiode 260 and amplified by the monitor amplifier 324 with a set voltage by the comparator 234, and integrates the comparison value is referred to as an optical output stabilizing means.

The analog switches 240 and 241 are switched by the main exposure setting signal S44. That is, when the main exposure setting signal S44 is at the 10W level, the output level of the inverter 242 becomes the l-11GH level, and the analog switch 241 is turned on. Also,
When the main exposure setting signal 844 is at HIGH level, the output of the buffer 243 becomes -IIG)-level, and the analog switch 240 is turned on. The outputs (S side) of the analog switches 240 and 241 are also input to the voltage follower 261, and the output S50 of the voltage follower 261 is used to correct the threshold level of the horizontal synchronization pulse detection comparator of the beam detection circuit, which will be described later. used.

Next, the current-output characteristics of the laser diode used in this printer will be explained. Figure 18 is I
It is a graph of F-Po characteristics. TC-0℃ is the IF-Po characteristic when the case temperature of laser diode 344 is 0℃,
Same <TC=25℃, when case temperature is 25℃, TO=50
°C is the IF-Po characteristic when the case temperature is 50 °C. Taking the characteristics of case temperature TC=25° C. as an example, when the current IF flowing through the laser diode 259 is increased sequentially from 0, the optical output PO starts to be output from a point of about 50 mA. Then, at the point of IF=68mA, the above P (O
The optical output of N> is 6 mw.

Therefore, even when TO=0°C, the optical output PO starts to be output at a point of about 40 mA, so by turning on the transistor 258, the bias current IFB is always turned on when the laser enable signal 849 is at a HIGH level. The power loss of the laser modulation transistor 257 is reduced.

Therefore, the operation of the laser modulation transistor 257 is guaranteed to be extremely stable even at high temperatures due to the effect of the bias current rFB. Also, if the amount of change in current required to modulate the laser is, for example, TC = 25°C,
Compared to directly driving a current of 1F25-IFB with the transistor 257, the accuracy of the light amount stabilization operation described later can be considerably improved. Furthermore, as is clear from the graph, the output of the laser diode itself varies considerably depending on the temperature, so the light amount stabilizing circuit is required. In this laser light amount stabilizing circuit, the light amount from the laser diode 259 is detected by a monitor photodiode 260, and the short circuit current IS of the photodiode 260 is controlled so as to always be a constant amount. This is because, as is clear from FIG. 19, the monitor short-circuit current IS and the optical output po of the laser diode 259 are in a perfect proportional relationship.
If is kept constant, the optical output PO is always kept constant. Furthermore, the temperature-related drift of the photodiode 260 is very small, so even if the temperature changes, the amount of change in optical output can be ignored. Next, the operation of the above-described first horn stabilizing circuit will be explained using FIG. 17 and FIG. 20.

When the laser enable signal S49 and the sample signal 845 both reach the I''IGH level in FIG. 20, the transistor 258 in FIG. 17 is turned on, and the resistor R51
A bias current (approximately 30111A) flows through the laser diode 259.

Also, at this time, since both the print data signal 847 and the shadow signal 848 are at LOW level, the gate 2
Among the gates 4.6, 247, and 248, the inputs of only the gate 246 are all at the l-11GH level, so the output is at the t-OW level, and the analog switch 254 among the analog switches 254, 255, and 256 is turned on. Also,
When the sample signal S45 becomes HIGI-1, the analog switch 236 is turned on. At this time, since the capacitor CO7 is not yet charged, the output of the operational amplifier 237 is at OV, and the base of the laser modulation transistor 257 is also at OV. Therefore, at this point, only the bias current flows through the laser diode 249, and the laser diode does not emit light, as can be seen from the characteristics shown in FIG. Since no laser is emitted from the monitoring photodiode 260 of the laser diode, the monitor current IS is O, and since the operational amplifier 232 outputs OV, the output of the comparator 234 becomes LOW level and the transistor 235 is in the OFF state.

Since the transistor 235 is OFF, the capacitor CO
7 is charged through resistors R39 and R40. The time constants of the resistor R39°R40 and the capacitor CO7 during charging are selected to be about 20 to 50 msec. If this value is very small, the response of the stabilizing circuit will be too fast, and the fluctuations in the optical output level of the laser will become large. Moreover, if it is too large, the responsiveness will deteriorate and it will take time for the optical output to stabilize. As the capacitor CO7 is charged, the output voltage of the voltage follower 237 also gradually increases. Therefore, laser modulation transistor 2
As the base voltage of 57 increases, current flows through the collector. At this time, the transistor 257(7)-1L/
'1ffi style Ic is (VB-VBE(SAT))/R5
The current value becomes 0. A sum current IF of the bias current IFB from the transistor 258 and the current IC from the transistor 257 flows through the laser diode 259 . Then, the current Jc increases and the laser diode 2
The 7-k'17-mode current IF of 59 is approximately 50 mA (
TC=25° C.), the laser diode 259 emits light. When the laser diode 259 emits light, the monitor current of the monitor photodiode 260 flows in accordance with the emitted light output, and the voltage at the input terminal of the operational amplifier 232 increases, and its output voltage also amplifies the input voltage. The value is output. The amplification degree of the operational amplifier 232 is 1 m from the output of the laser diode 259.
Since the output voltage of the operational amplifier 232 is adjusted in advance by the volume VROI so that the output voltage of the operational amplifier 232 is approximately 0.5 V with respect to w, the optical output of the laser diode 259 increases to approximately 2 mw, and when the output voltage of the operational amplifier 232 reaches approximately 1 V, the comparator The output signal of 238, that is, the laser ready signal S43 changes from LOW to HIGH level. Since the main exposure setting signal S44 is at the LOW level, the one side input terminal of the comparator 234 is connected to the shadow exposure level (light output P (
SH)) voltage is applied. This voltage is applied to the photoreceptor 30
The shadow exposure level voltage is set according to the sensitivity characteristics of 1 by a shadow exposure setting volume 361 in the operation section. Now, the voltage corresponding to the average value of 4 mw of optical output is 2. Suppose that it is OV. Therefore, when the optical output of the laser diode 259 increases and the voltage at the input terminal of the comparator 234 exceeds 2.0■, the transistor 235
turns on, and capacitor CO7 is discharged through resistor R40. Therefore, the base voltage of the laser modulation transistor 257 also decreases, and the laser diode 2
The optical output of 59 is less than 4mW. When the optical output of the laser diode 259 becomes 4mW or less, the comparator 23
The voltage at the child side input terminal of No. 4 also becomes 2.0 V or less, and the transistor 235 is turned off again.

Then, the capacitor CO7 is charged up again through the resistors R39 and R40. Then, the laser diode 259 again changes its optical output around 4 mW, and the comparator 234 repeats the 0N10FF operation at a constant cycle. In addition, since this comparator 234 has hysteresis characteristics, comparison judgment becomes stable.
Be able to make reliable judgments. And the resistor R3
9 and R40, the voltage across the capacitor 007 approaches the value of VOl in FIG. 20 and becomes stable. After the laser ready signal 843 reaches the IIGH level, the microprocessor 101 outputs a shadow level sample strobe signal 846 after a predetermined time t6 through the output port. When the sample strobe signal is output, the sample hold 1c245
The voltage VO1 (FIG. 20) of the capacitor CO7 input to the NALOG-INPUT input terminal is sampled and held, and the voltage is stored in the hold capacitor CO8. Therefore, after the sample strobe signal is turned off, the control voltage vO1 for producing the shadow level P(St-1) continues to be output to the output 0LIT of the sample and hold IC.

Next, when the sample and hold operation for the shadow level P (St-1) is completed, the microprocessor 101 sends the main exposure setting signal S44 to 1"I through the output port.
GH Switch to H level. Therefore, the output voltage of the voltage follower 239 is applied to one input terminal of the comparator 234 through the analog switch 240. The voltage follower 239 outputs a main exposure level (light output P(ON)) voltage. This important voltage is set by the main exposure setting volume 360 in the operation unit according to the thinning-sensitive characteristics of the photoconductor 301, and currently the voltage is 3.0 cm, which corresponds to an average light output of 6 mW.
Assume that is output. Therefore, comparator 23
For the output of 4, one side input terminal is 3. By switching to OV, the level becomes LOW, and the transistor 235 turns off. Therefore, as the capacitor CO7 is further charged up, the base voltage of the laser modulation transistor also increases, and the optical output of the laser diode 259 also increases. When the optical output of the laser diode 259 becomes around 6 mW, the output voltage v2 of the operational amplifier 232
32 becomes approximately 3■. The output voltage of the operational amplifier 232 is 3
(2) When the shadow level is set, the output of the comparator 234 changes to -11G)-1, the transistor 235 is turned on, and the capacitor CO7 is discharged through the resistor R40. Therefore, the base voltage of the laser modulation transistor 257 also decreases, and the optical output of the laser diode 259 becomes 6 mW or less. When the optical output of the laser diode 259 becomes 6mW or less,
] The negative input terminal voltage of the comparator 234 also becomes 3.0 V or less, and the transistor 235 is turned off again. Then, the capacitor CO7 is charged up again through the resistors R39 and R40, and the optical output of the laser diode 259 becomes 611W or more.

In this way, the optical output of the laser diode 259 is 6tII.
Centered around W] The comparator 234 repeats the 0N10FF operation at a constant cycle. And the resistors R39 and R
Due to the integral effect of 40, the voltage of capacitor CO7 approaches VO2 in FIG. 20 and becomes stable. When the setting of the main exposure level is completed, the microprocessor 101
starts the operation of a sampling timer, which will be described later, and writes print data to the photoreceptor 301. The sample timer is triggered one after another at a constant period T each time a laser beam detection signal, which will be described later, arrives, and outputs the sampling signal 845 only in a portion other than the print data write operation, that is, in the period shown in FIG. 20a. Since the sample signal 845 is at the LOW level in the section of the print data 847 and the shadow data 348, the analog switch 236 is turned off. Therefore, the laser diode 25 is activated by the print data D47 and the shadow signal 848.
9 is a laser diode 259 in the printing area to be modulated.
The optical output level of P(ON>, P(
There are three levels: SH) and P (OFF). That is, first, the print data signal S47 is OFF, that is, LO
When the shadow signal is OFF at W level, that is, it is LOW level (the output of printing is white), the NAND gate 246 is established and only the analog switch 254 is ON.
Therefore, the main exposure level voltage VO2 is applied to the base of the modulation transistor 257, and the optical output of the laser diode 259 becomes P(ON>=6 mw.The second case is when the print data signal 847 is OFF and the shadow signal is ON. NA in case (halftone as printing output)
The ND gate 247 is established, only the analog switch 255 is turned on, the output voltage 01 of the sample and hold IC 245 is applied to the base of the modulation transistor 257, and the optical output of the laser diode 259 is P(S
H)-4iw. Third, the print data signal 847 is O
N, when the shadow signal is OFF (the print output is black), the OR gate 248 is established and only the analog switch 256 is turned ON. Therefore, the base of the modulation transistor 257 is shot to GND and becomes OV, so the optical output of the laser diode 259 is P (OFF
) −〇 and no light is emitted. In this manner, the first printing is performed. When printing is completed, the microprocessor 101 sets the main exposure setting signal 844 to LOW level again through the output port, and the shadow exposure level P
(SH) is reset. Therefore, comparator 234
The voltage at one side of the input terminal becomes 2.0V, which is the setting voltage for the shadow exposure level. Therefore, the transistor 235 is turned on, and the capacitor CO7 is discharged and the VC
O7 is getting smaller. In order to explain the optical output stabilization operation of the laser diode, it is assumed that the case temperature of the laser diode 344 increases by 8T during the second printing operation. As is clear from the characteristic diagram in Figure 18, as the case temperature increases, the IF-Po characteristic curve of the laser diode shifts to the right, and when the same current is passed through the laser diode 259, the optical output PO decreases. I end up. Therefore, in order to obtain the same optical output, the current Δ corresponding to the characteristic curve shifted to the right side is
Only IF must be increased. Therefore, the voltage VCO7 of the capacitor CO7 is set to VO3 which is higher than the first setting voltage v01 by the voltage Δ■1 corresponding to the ΔIF, and the optical output of the laser diode 259 is the same as the first setting P(SH)= It is set to 4mw. Then, similarly to the first time, the shadow exposure level P (ON) is set in the sample hold IC 245 by the sample strobe signal 846. At this time as well, the operation corresponds to the rise in the case temperature of the laser diode 344.
The voltage of capacitor CO7 is a correction voltage △■ due to temperature rise
The VO4 is set to a higher value by 2, and after the setting, printing is performed on the second circle of the cylinder. In this way, the shadow exposure level P
(SH) and the main exposure level P(ON) are very accurately maintained at a constant level by the function of the stabilizing circuit, thereby making it possible to perform high quality printing. Incidentally, as described above, the main exposure level P (ON) performs a light amount stabilizing operation so that the light output is always kept constant except when printing data is being written. Furthermore, for the shadow exposure level, a sample hold operation is performed before each print starts, and unlike the main exposure level, a light amount stabilization operation is not performed during the print writing operation. This is because the circuit becomes complicated and expensive, and the shadow level is an auxiliary element compared to the fluctuation of the main exposure level, so even if it fluctuates a little, it does not have much effect on the printing quality. In addition, when changing the setting voltage input to the comparator 234 according to the sensitivity characteristics of the photoreceptor 201, the adjustment is made by changing the main exposure setting volume 360. This main exposure setting volume 360 is connected to the voltage follower 239.
The input voltage can be varied. Therefore, by changing the main exposure setting volume 360, P(ON
) can adjust the light output setting voltage. On the other hand, P(St-
The optical output setting voltage at the time of 1) is the voltage follower 2.
39 is divided by a resistor R46 and a shadow exposure setting volume 361. Therefore, by adjusting the main exposure setting volume 360, P
(ON) and P (S) I), the optical output setting voltage changes proportionally, and a constant relationship between the recording density and the applied voltage can be maintained. Therefore, P(
The adjustment becomes simple without requiring the complicated operation of varying and adjusting the set voltages at both the ON) and P(S)l) times.

FIG. 21 is a detailed circuit diagram of the beam detection circuit 121 and beam detector 346 in FIG. 13.

In FIG. 21, 346 is a beam detector that uses a PIN diode with very fast response. Further, this beam detector 346 is connected to the photoreceptor 301 as shown in FIG.
The pulse width and pulse generation position must be extremely accurate.

Therefore, if the pulse width, pulse generation position, etc. vary with each beam scan caused by the rotation of the polygon mirror 313, the writing start point on the photoreceptor 301 will vary, resulting in poor print quality. The anode side of the beam detector 346 is connected through a load resistor R52 and a resistor R55 to one side input terminal of a high-speed comparator 262, which is a comparison means. In addition, the + side input terminal of the comparator 262 has resistors R53 and R5.
A voltage divided by 4 is applied through the resistor R56. Further, a capacitor C12 for noise removal is connected in parallel to the resistor R54. Further, R57 is a positive feedback resistor for providing hysteresis characteristics, and C13 is a feedback capacitor for applying high-speed feedback to improve the output waveform. In addition, a diode D4 is connected to the + side input of the comparator 262.
Threshold variable voltage 8 through 0° resistor R57
50 is applied. This threshold variable voltage S
50 is the output of the analog switch 240 or the analog switch 241 (output of the optical output setting means) (see FIG. 17). FIG. 22 shows the relationship between the one-side terminal input waveform of the comparator 262, that is, the output waveform of the beam detector 346, the positive terminal voltage of the comparator 262, and the relationship between the output waveform of the comparator 262 at that time. When the laser beam passes over the beam detector 346 at high speed, a pulse current flows from the beam detector (PIN diode) to one input terminal of the comparator 262, as shown in FIG.
The waveform b is input. Assuming that the voltage at the + side input terminal of the comparator 262 is always a low voltage VO6 because the threshold variable voltage 850 is not applied, the output waveform of the comparator 262 is waveform a as shown in the dotted line. If the waveform is S, the output waveform will be as shown by the solid line. Here, waveform a is the photoreceptor 3
01 shows a waveform when the sensitivity is low and the laser output during the main exposure is 6+++w or more; conversely, it shows a waveform when the sensitivity of the photoreceptor is high and the laser output is 6w+w or less. As can be seen from this output waveform, when the positive voltage of the comparator 262 is kept constant, the output waveform changes significantly depending on the amount of light incident on the beam detector 346. Therefore,
By using the threshold variable voltage 850 to correct the voltage of VO5 when the light intensity of the laser beam is large and the voltage of VO6 when it is small,
As shown in FIG. 22, the output waveform can be kept almost constant.

FIGS. 23(A) and 23(B) are configuration diagrams of the beam detector (PIN diode) 346. Figure 23 (A), (
In B), 410 is a light receiving element, 411 is an electrode wire, 41
2 is a mask plate, 413 is a laser scanning beam, 414 is a light receiving element mounting base, and 415 is an output lead wire. The PIN diode used in this example has a photodetector shape of 2.5x2.51111 and a response time of 4n5e.
It is of c.

The laser beam 413 is scanned at a constant speed in the direction of the arrow in FIG. 23(A) by the rotation of the polygon mirror 313. When the laser beam 413 passes over the light receiving element 410, an output current flows according to the optical output of the laser beam 413. At this time, the input J waveform of the one side input terminal of the comparator 262 in FIG.
The waveform will be as shown in the figure. In FIG. 24, input waveform 1 is a waveform when there is no mask on the light receiving element 410, and noise is generated before and after the output waveform. This is mainly intended for cases where the light receiving element 410 itself is used for detecting light that is originally stationary or for detecting light that has a very slow speed even when it is being scanned, and the parallelism of the end face of the light receiving element 410 is If the laser beam passes through the end face of a bad element, the output current becomes unstable. Therefore, in order to solve these problems, the light receiving element 410
By attaching a mask 412 that does not allow the laser beam 413 to pass on the light-receiving surface of the laser beam, cracking of the output waveform when the beam passes on the end face is prevented. The mask 41
2 is a light receiving element 41 as shown in FIGS. 23(A) and 23(B).
The laser beam 4 is provided with square windows in an irregular structure in the end face portion of the laser beam 4 and the portion that does not include the lead-out portion of the electrode wire 411.
13 allows light to hit the light receiving element 410 only when it passes through the four corner windows. With this structure, by increasing the precision, especially the parallelism, of the window portion of the mask, the input waveform to the comparator 262 can be a waveform that does not contain noise, as shown in input waveform 2 in FIG. 24.

FIG. 25 is a detailed circuit diagram of the print data write control circuit 119 in FIG. 13. The main functions of this print data write control circuit 119 are as follows:
The parallel print data 857 is serially converted to be written in a predetermined area on the photoreceptor 301 according to the size of the paper to be printed, and sent to the laser modulation circuit 120. In addition, the print data S
A shadow signal for improving print quality is generated from the data contents of 57 and sent to the laser modulation circuit 120 together with the print data. Further, the laser modulation circuit 120 sends out signals necessary for setting the optical output. Furthermore, a timing signal for controlling output from the print data control section 2 is sent to the interface circuit 122. The other is to generate test printing patterns necessary for maintenance.

In FIG. 25, 186 is an input/output port for transmitting and receiving signals necessary for control within the laser modulation circuit 120 and print data writing control circuit 119;
A counter/timer 188 controls the writing position of print data, test pattern generation, laser light output sampling, and the like. 189 is a crystal oscillator that serves as the reference clock for the image clock pulse and has an oscillation frequency of approximately 32M.
1-1 z. 190 is a circuit for generating an image clock, which generates a pulse (approximately 8 MHz) corresponding to one dot, the minimum modulation unit of a laser beam. 191 is a control counter for serially converting print data in bytes (8 bits) received from the interface circuit;
2 is a circuit that generates a test pattern used during maintenance; 211 is a multiplexer that selects between test pattern data and print data from the interface circuit 122; and 210 is a circuit that converts the 8-pit parallel data from the multiplexer 211 into serial data. Shift registers 213 and 214 are line memories for temporarily storing print data and have a memory capacity of 4096 bits, 212 is an address counter for the line memories 213 and 214, and 215 is a line memory for generating signals to control the test pattern generation circuit. It is a decoder. , 226,227.22
Reference numeral 8 denotes a flip 70 for synchronizing the print data and shadow data sending timings.

Here, the details of the counters 187 and 188 will be explained. A counter 275 determines the timing for correcting the amount of laser light for each line (horizontal scanning line), counts based on the reference clock signal S53, and generates a sample signal 875 used for correcting the amount of light and starting the line. A counter 276 for determining the horizontal recording start position is counted based on the Q7 output (video first dot unit signal) S83 from the control counter 191 and outputs a horizontal recording start position (left margin) signal 884. A counter 277 determines the recording end position in the horizontal direction, and counts based on the video 8-dot unit signal 883, and outputs a data writing end position (write margin) signal 885. 278 is a counter for vertical recording start positioning, and counts based on the output of the gate 198 which is powered by two people: the paper leading edge position (page top) signal 874 output from the input/output port 186 and the Q output of the flip 70 knob 204. is performed and generates a page top count output 876.

279 is a vertical recording end positioning counter which counts based on the output of the gate 198 as described above and outputs a page end count signal 877. 280
is a vertical test pattern control counter that performs counting based on the Q output of the Noritub flop 240 and outputs a test pattern control signal 879.

FIG. 26 shows the interface circuit 12 in FIG.
2 is a detailed circuit diagram of No. 2. In FIG. 26, reference numeral 263 denotes an input/output port 1 which receives command data and print start command signals from the data control unit 2, and sends status data and ready status signals of the print control unit to the data control unit 2. -, 264 are 8 bits for both cloak and print data. Trunk 265 is a transceiver/receiver for interface data bus 859. Reference numeral 266 indicates a decoder for the data selection signal 860 that specifies data on the data bus S59, and 269 indicates a control circuit for the 5usy signal that controls the data sending timing to the data control unit 2 when receiving command data and print data.

Next, details of the interface signal will be explained. In FIG. 26, 859 is a bidirectional 8-bit data bus, 860 is a data selection signal on the data bus 859, and 860 is an ID signal on the data bus 859.
Data on the data bus 859 is selected by a combination of two signals cOM and ID5TA. 861 is IPRDY
A signal indicating that the print control unit 100 is in a ready state.

862 is IPREQ, a signal that allows the data control unit 2 to send the print start signal I PRNT, and S63 is the IP
At END, the data control section 2 receives this signal and stops sending out the print data.

864 is Il-ISYN, which is a request signal to send one line of print data, S65 is IPRNT, which is a print start command signal, S30 is a command and print data strobe signal, abbreviated as 15TB, and 866 is IBSY, which is the strobe signal 330. This is a signal that allows transmission permission and permission to read status data on the data control unit 2 side.

Commands and print data are sent to transceiver/receiver 26
The status identification signal 868 is output to the output line 872 of 5.
It is output when it is FF. Data on output line 872 is transferred to data latch 264 by strobe signal S30.
latched to. In the case of command data, it is latched to the input/output port 263, and after identifying the command, the specified operation of the command is executed. In the case of print data, it is sent to the print data write control circuit from the output [1859]. Also, the status data is sent as follows. By receiving a status request command on the print control unit 100 side, the status contents corresponding to the command are set in the status data output 871 of the input/output port 263. The set status data S71 is input to the transceiver/receiver 265. The input data is the status identification signal 868
is ON, it is output on the data bus 359.

Details of commands and statuses used in the print control section 100 are shown in FIGS. 27 and 28, respectively.

In FIG. 27, SR1-SR6 are status request commands corresponding to status list 6 in FIG.

PSON is a power save command that reduces the power consumption of the fixing device 331, and PSOF is a command to cancel the power save state.When not recording, the power save command PSON reduces the power consumption of the fixing device 331 to save power, and when recording Sometimes power save cancellation command P
SOF allows the power to be increased to normal values to offset toner fusing. C3TU is a cassette upper stage paper feed specification command, C3TL is also a lower stage specification command,
VSYNC is a command that instructs the data control unit 2 to start sending print data, MF1-9 are manual feed mode designation commands, TBM1-4 are top/bottom margin designation commands that designate the print start position on paper, and SOF is a shadow command. The commands for forcibly turning off exposure are shown below.

In Fig. 28, during paper conveyance, the status indicates that paper is being fed and the paper is being conveyed into the printer, and the select switch ON is the select switch 354 of the operation unit.
The VSYNC request status indicates that the print control unit 100 has received a command to start printing and is now ready to receive print data, and the manual feed status indicates that the paper feed mode is manual feed mode. The status to notify, upper/lower cassette is the status indicating the status of the selected cassette in the cassette feeding mode, and top/bottom margin is the status of the top/bottom margin selected by the top/bottom margin commands (TBM1 to 4). status, cassette size (
Upper row) and cassette size (lower row) are the statuses that indicate the size code of the installed cassette, Test/Maintenance is the status that indicates the test/maintenance state, Data resend request is when reprinting is required due to jam etc. The status indicates that the printer is in the warm-up state of the fixing unit during wait, and the status indicates that the printer is in power save mode by the power save command (PSON>). Serviceman call indicates that a serviceman call factor with status 5 has occurred.Tray full indicates that there are more than the specified number of sheets in the paper output tray and the tray is full. Toner pack replacement indicates that the toner pack is full of toner. Paper jam indicates that paper has jammed inside the machine. No toner indicates that there is no more toner in the toner hopper. .Cover open indicates that the front door is not closed.Timing error indicates that there was a problem in transferring print data.Fuser failure indicates that there is an abnormality in the fuser, such as the fuser heater being disconnected or the temperature FLJSE being out. A laser failure indicates that the laser diode does not reach the specified output, or the beam detector cannot detect the beam.A scan motor failure indicates that the scan motor does not rotate at the specified rotation speed even after a certain period of time after startup. This indicates that the specified rotation speed has not been reached or that the specified rotation speed has been deviated from the specified rotation speed for some reason.

Heat roller replacement indicates that the fixing roller counter shown in FIG. 15 has reached a specified value and that the fixing roller needs to be replaced. Drum replacement similarly indicates when the drum replacement counter reaches a specified value and the drum needs to be replaced, and developer replacement similarly indicates when the developer replacement counter reaches a specified value and the developer needs to be replaced. .

FIG. 29 shows the positional relationship between one scanning range of the laser beam including the beam scanning section 349 on the photoreceptor 301 in FIG. 3, and the beam detection position and data writing position that fall within the scanning range. FIG. In FIG. 29, 416 is the beam scanning start point, 417 is the beam scanning end point, and the beam that has reached the beam scanning end point 417 is moved to the next surface from the beam scanning starting point 416 at time O by the next surface of the polygon mirror 313. Begin beam scanning. 418 indicates the beam detection starting point of the beam detector 346, 428 indicates the left end surface of the photosensitive drum, and 429 similarly indicates the right end surface. 419 represents the left end surface of a sheet of paper size A3, and 420 similarly represents the right end surface. 421 represents the left end surface of a sheet of paper size A3, and 420 similarly represents the right end surface. 421 is the same A
The data writing start point 422- also indicates the data writing end point for the three sizes of paper.

423 is the left end surface of paper size 80, 424 is the right end surface, 425 is the data writing start point of the same size, 426
Similarly, each represents the data writing end point. Also 42
7 represents the center point of the paper.

d4 is the distance from the beam scan 418 to the A3 size writing start point, d5 is the same < distance to the A6 size writing start point, d6 is the same < distance to the A6 size writing end point 426, d7 is A3 size Each represents the distance to the writing end point. d8 represents the distance from the beam detection point 418 to the right end surface 420 of A3 size paper. Further, d3 represents the range of one scan of the beam. d14. d9. dlo indicates the effective printing range in A3 and 86, respectively. As is clear from this drawing, the paper feed of this printer is always centered around the paper center point 427, so the starting point for printing from the beam detector position 418 differs depending on the paper size. It is necessary to write data after a lapse of time corresponding to the distance from when the detector 346 detects the beam to each writing start point. Instead of performing such control, this printer does not use a paper edge feed mechanism, so it is possible to print on the entire surface of the paper. In this embodiment, the left and right margins on the left and right sides of the paper are set to 3 mm, but it is possible to set them to O. In addition, for printers that use conventional edge-feeding conveyance, a margin of about 8 to 10IIIm is usually required.
The drawback is that a fairly large portion of the paper is not printed.

FIG. 30 shows the paper size and print area portion of FIG. 29 not only in the horizontal direction but also over the entire surface of the paper. In FIG. 30, 436 represents A6 paper and 437 represents A3 paper. 419,420°421.422,423,4
As for 24,425,426.427, the same positions as in FIG. 29 are shown. 430 represents the leading edge of the paper, 432 represents the data writing start point in the vertical direction of the paper, 431 represents the trailing edge of the A3 size paper, and 433 represents the data writing end point of the A3 size. 434 represents the paper edge of F6 size, and 435 represents the data writing end point of A6 size.

Next, the operation of the component device will be explained with reference to the time charts of FIGS. 31 and 32.

Ready signal IPRDYO of print control unit 100 (S61)
becomes ready for printing.

At the same time, the print start signal IPREQO (862) becomes active. Next, the laser enable signal LDONI
(849) rises to 1'. This signal 849 causes the first
The transistor 258 shown in FIG. 7 is turned on. At this time, the data flip 70 tabs 226 to 228 in FIG. 25 are not set, so the print data signal 847 and the shadow signal 848 are both "0". Since the data is 0' and the shadow signal 848 is 0', the gate 246 in FIG.
is established and the analog switch 254 is turned on, causing the laser diode 259 to emit light. Then, the monitor photodiode 260 operates, the operational amplifier 239 operates via the operational amplifier 232, and a laser ready signal LRDY1 (843) is generated. Next, in synchronization with the horizontal synchronization signal H8YO (854), the counter 27
A sample signal SMPTO (875) is generated from 5.

This signal 875 is used to set the time corresponding to the distance d3 (distance of one line) between 416 and 417 in FIG. 29 that defines the paper size. This allows the light amount to be corrected for each line and is used as a line start signal. That is, this signal 875 opens the gate 193 in FIG. 25, a sample signal 845 is generated from the gate 194, and this sample signal S45 passes through the gate 244 in FIG. 17 to the analog switch 23.
6 is turned on, a correction signal is given to the laser diode 259, and thus light amount correction is performed for each line. PTCTO (876) is an output signal of a counter (page top counter) that determines the leading edge of the paper, and PECTO (877) is an output signal of a counter (page end counter) that determines the end position of the paper. When it is time to write the image, VSYNC
Send request status to external device. Due to the stiffness, a VSYNC command is issued, and when it is received, PTOP
(873) appears and start counting the number of H8YNC lines from that point. In the same way, specify the number of books from that position (thus the end position). A top margin nT and a hot margin nE are provided to allow this designated value to be changed. When the above specification is made, VS
When YNC arrives, a PTOP signal is output before the leading edge of the paper. For example, if a margin of 5ml11 is required, count the number of lines including that margin.

If the top value is 1001111, the corresponding data will be set in the timer. The position of the bottom can be determined in the same way. Once the data is set in the timer, the gate is opened and counted.
It stands up when the count ends. Gate 201 in FIG. 25 determines where to write in this way.

LS-rO (878) has 7 lip 70 for synchronization.
Q output of knob 204, set by H8YNC and reset when the sample timer signal rises.

This reset line is connected to the LDON signal (S49
), and the reset line normally does not work, but a reset is forced. Due to the reset, the Q output of the flip 70 tube 204 is generated, and the clock generation circuit 190 operates to count the clocks from the oscillator 189. This clock generation circuit 190 is an oscillator 189
The frequency of the clock is divided by four, and a bit-by-bit signal is output only while the line start signal LST is set. This output has two types of signals 882 and 8 with different phases.
It's now 87. As a result, synchronization for -lines is achieved. VDATl is the print data signal (847>, P
The signal is output as serial data by the operation of the /S conversion shift register 210. That is, the P/S conversion shift register 210 receives the signal 882 from the clock generation circuit 190.
However, when the load signal is not applied, the output 386 is 0' (no laser writing).
When the load signal 888 is input, data D5 to D12 are serially converted and output.

At this time, gates 207 to 209 provide 1 to 8 bits.
It will be loaded every cycle. Here, the generation timing of the load signal will be explained.

When there is a place where you actually want to write, data must be set every time the paper size changes, but the counter that controls this is the left margin counter 276 (Fig. 25).
The data is 69 in Figure 29. dlo) and write margin counter 277 (data is dll and d12 in Figure 29)
It is. In this case, the set defines the distance between the left and right sides based on the center of the paper. H8YNC
When the LST signal (878) is output in synchronization with the signal, the flip 70 knob 196 is set, and the gate 198 is thereby set.
The counter 276 starts counting. In this case, the video clock is not counted bit by bit, but once every 8 bits. When the count output that is output every 8 bits is set in accordance with the left margin N1m1 right margin NRm, counting is performed in synchronization with the LST signal (378). Then, it starts up after setting and outputting the count number. Therefore, the gate 201 determines the vertical direction, and the gate 199 determines the horizontal direction, so that writing is performed at the point when the outputs of both gates become (1, 1). At this timing, the load signal is output, and the data S86 is serially converted from the shift register 210 and sent out.

Line memory out signal LMOT (S80) is the output of OR gate 222. This controls which data from the line memories 213 and 214 is to be sent. That is, this sending timing is
Controlled by 03. That is, the output state of the flip-flop 203 changes every time a clock pulse is applied, and the gates 220 and 221 are opened alternately, so that the output DOUT of the line memory 213 or 214 is alternately read out. line memory 213
．． The writing timing to 214 is also game-1-217,2
18 are opened alternately and controlled. This is done in order to facilitate processing by allowing data to be written and read at the same time when a shadow method, which will be described later, is employed.

Next, LDAONI (881) will be explained with reference to FIG. 43.

In this type of recording device, if the laser is not applied over the entire surface of the photoreceptor 301 in the axial direction, for example, only small-sized paper (such as B5 or A4 paper such as paper 458 shown in FIG. 43) is used. In many cases, printing is not performed, and as a result, toner and the like do not adhere to the area near both ends that are not used. Further, even for a large size paper (for example, paper 461 in FIG. 43), there is an unused area (the used area for small size paper 458 is also within the shaded area 459). If such an area is provided where toner does not adhere for a long period of time, there is a problem that when the blade scrapes off the adhered toner after recording, the contact resistance of the blade in the unadhered area becomes large and the surface of the photoreceptor is scratched. be. So with this device. As shown in the time chart of FIG. 31, the line data on signal LDAON1 (B81) is generated immediately after printing for one sheet of paper is completed, and within this generation period, the print data signal VDATI
(847) is forcibly applied, and by this operation, lines (images) 460 and 463 spanning the entire axial direction of the photoreceptor as shown in FIG. 43 are written after printing for one sheet of paper is completed. This eliminates the above drawbacks. In this case, the timing for writing line data is the data LDAT one step before the final stage data LDATn in the data of the line memory out signal LMOTI (880).
The signal is generated when a predetermined time tx has elapsed from the falling edge of n-1. Note that such lines are not necessarily drawn periodically after each sheet of paper has been printed, but are drawn on a lot basis (for example, every 10 sheets or 100 sheets).
You may also set it so that it is written for each page).

Next, with reference to Figures 33 to 36, we will explain in detail the method (also called shadow method) used to make characters easier to see by adding "shadows" to printed characters. .

Determination as to whether or not to generate the shadow signal 848 is made by various gates 220 to 225 which alternately input the data of the line memories 213 and 214, and three 7-lip 70-tubes 2.
26 to 228 and the gate 231 on the output side thereof. Among them, the flip-flop 227 is in the horizontal direction (
The flip 70 knob 228 contributes to determining shadows based on level changes in the vertical direction (line direction). In other words, from the line memory 213, The serial data to be written is read and this is 7 rip 70
If the knob 226 is set, the data in the previous line direction is stored in the flip 70 knob 227, so for example, if the current data is O' and the previous data is 1' (the shadow signal 848 is output). Similarly, the data of the previous line and the data of the current line are compared at the gate 223, and for example, when the data of the current line is "0" and the data at the same horizontal position of the previous line is "1", the data of the previous line is 7 lip-flops. is set and a shadow signal is generated.A shadow signal is also generated when both flip 70 tabs 227 and 228 are set.This state is expressed as the shadow out signal 5OLJT1 (886) and print data signal VDAT1 (347) in FIG. , Shadow signal 5DAT1 (
S48).

FIG. 33 shows a conventional development pattern when the shadow method is not used, and FIG. 34 shows a development pattern when the shadow method is used. In this way, when the character "謹" is printed, a shadow is added to FIG. 32, making it very easy to see.

FIG. 36 is a characteristic diagram PA that intersects vertical line S1 and horizontal line S2 and shows the relationship between exposure position and exposure energy in the upper right area of the figure.
T1. For FAT2, a characteristic 8Q showing the relationship between the surface potential of the photoreceptor and exposure energy is shown in the upper left area of the drawing, and characteristic diagrams R1 and R2 showing the relationship between the exposure position and the surface potential are shown in the lower left area of the drawing. In this figure, among the characters in Figs. 33 and 34, "8" in the X direction and "14" in the Y direction.
~21'' is extracted. As shown in the figure, the third
The characteristics PAT1 and R1 of the pattern shown in FIG. 3 are different from the characteristics PAT2 and R2 of the pattern shown in FIG. In particular, regarding the development characteristics, at a certain development level L, the width D1 of R1 in FIG.
It can be seen that the width D2 of R2 in the figure is larger. In addition, FIG. 35 is a characteristic diagram showing the relationship between exposure position and exposure energy, and the energy of P(ON) during laser irradiation is, for example, 6 mw, and P(SH) when creating a shadow part.
The energy is, for example, 4 mW.

The above shadow method can be summarized as follows.

In a device that records recording information (character information, etc.) on a recording photoreceptor by beam scanning in accordance with differences in beam intensity, serial binary input data is transferred to beams having first and second intensities (the P (ON) and P(OFF)), and when the input data has a specific relationship, the first or second intensity intermediate beam is replaced with the first or second intensity beam. Recording is performed using a beam of a third intensity (halftone) located at the horizontal line. It is determined that the binary data changes from significant recorded data (data for forming characters) to unintentionally recorded data (data that does not contribute to character formation), and the unintentionally recorded data part immediately after the change is determined. scanning with a beam of a third intensity; and (b) comparing the data of the current line in the horizontal line with the data of the previous line in the vertical direction corresponding to that position, and significantly When changing from recorded data to unintentionally recorded data, the unintentionally recorded portion immediately after the change is scanned with a beam of a third intensity.

Note that when adding the shadow, it may be applied regardless of the type of recorded information (for example, text information and image information), but
It is preferable to use this method only when dealing with textual information. In this case, as shown in the flowchart in FIG. 55 (A), the microprocessor determines whether the flow is "Shadow" or not. If it is something (for example, image information), I disable "shadow" and let it do it automatically. The command in this case is rsONF shadow 0N10FF shown in Figure 27.
It is J. Or on the panel part "Shadow 0N10F"
An FJ switch may be provided so that the operator can select it arbitrarily.

If the above-described shadow method is used, if the recorded information is character information, a "shadow" can be added, thereby improving printing quality. Particularly during high-density beam recording, the printing density of one dot line decreases, which is a drawback of the conventional recording method using binary beam intensity.
As a result, the printing density of one dot line is increased, so that the printing quality can be improved even for a high-dot Kanji font such as a 40×40 dot configuration. Furthermore, since the permissible range of the vertical deflection of the beam on the photoreceptor due to the "plane deflection" of the polygon mirror can be widened, the polygon mirror can be easily processed and has the advantage of being inexpensive.

In addition to character information, the shadow may also be applied to simple graphic information.

Next, regarding charge correction, FIGS. 37 to 41 and 56
This will be explained with reference to the flowchart shown in the figure.

FIG. 37 shows an example of a configuration in the charging high voltage power supply circuit 160, which is a configuration example of the high voltage power supply 0N10FF signal S.
A voltage control circuit 445 whose operation is controlled by 35, a step-up transformer 446 whose frequency output is applied to the primary side by this voltage control circuit 445 and which generates a high voltage output from the secondary side, and a step-up transformer 446 which rectifies the output of the step-up transformer 446. a high-voltage rectifier circuit 447 that applies a rectified output to the charger 304; a current/voltage conversion circuit 450 that inputs the current flowing to the charger 304 and converts it into a voltage;
The operational amplifier 449 has one input as the output of the current/voltage conversion circuit 450 and the other input as the output of the control reference voltage generation circuit 448. The control reference voltage generation circuit 448 is controlled by an analog control signal 836 to output different control reference voltages. According to such a configuration, the output frequency of the voltage control circuit 445 is determined based on the output from the control reference voltage generation circuit 448, and a high voltage output is generated based on this, and the current of the charging charger at this time is determined. Current/
This output voltage is applied to the voltage conversion circuit 450, and the operational amplifier 449 compares this output voltage with a reference value, and a control operation is performed so that the two match, so that the output applied voltage can be stabilized.

Here, the contents of the analog control signal 836 will be explained in detail.

As shown in FIG. 38, the photoreceptor 301 has a characteristic that its surface potential changes significantly with temperature changes.

In the same figure, the horizontal axis shows mF&, and the vertical axis shows the amount of change in surface potential Δv.
O is shown, and the type of drum is 451°452.4
Each of the 53 types has different characteristics. Also, the third
Figure 9 shows each drum 451,452.4 when the temperature is 25℃.
This is a characteristic diagram showing the relationship between drum inflow current ID and surface potential VO of No. 53, which is a proportional straight line. Therefore, in order to keep the surface potential constant, it is sufficient to change the drum inflow current ID. For example, in order to maintain a surface potential of 800■ for the drum with characteristic 451 in FIG. Inflow current change amount ΔID corresponding to Δ■0−O
It can be seen that it is only necessary to increase the number by 0 (various characteristic data of the photoreceptor are stored in the RAM 107). Here, the inflow current ID and output current are 3 as shown in Figure 40.
The analog signal (input voltage) to the control reference voltage generation circuit 44 in the charging high voltage power supply circuit 160 is
The inflow current ID can be adjusted by changing S36 to 2V, 4V, and 6V. Figure 41 shows the analog input current (D/A converter 1 in Figure 15).
For example, the temperature of the drum 301 is measured by the temperature sensor 342 (the fourteenth one).
The analog control signal 836 may be applied in response to the temperature change by detecting the temperature using a thermistor shown in the figure.

The charging correction is performed based on the above contents, and its operation will be explained based on FIG. 56. 14th
When the thermistor 342 shown in the figure detects the temperature of the drum, the A/D converter 271 converts it into a digital signal, and when the data conversion is completed, the temperature data DTn and the temperature 25
A value DΔT is read by subtracting the drum temperature data DT25 when the temperature is °C. Next, the reference data DV2 at a temperature of 25℃
5 is read, DV25+DΔV is calculated, and the calculation result DVn is output to the D/A converter 165. Then, the drum characteristic No. is identified by referring to the drum characteristic 7'-cod RAM 107 at the address "6000" shown in FIG. 45(B), and further the feedback error data D
Read. Next, read the reference data DV25 at a temperature of 25°C, calculate DV25+DΔ■, and calculate the result D
Vn is output to the D/A converter 165. Then, Vn is applied to the analog input of the charging high voltage power supply 160 (3
36) as well as the control input signal 83 of the high voltage power supply 160 for charging.
5 is turned ON to perform correction. The above correction is repeated every time the temperature changes to keep the surface potential of the drum constant.

Note that the characteristics of the various photoreceptors (drums) stored in the nonvolatile RAM 107 can be specified by the operator from the outside. That is, as shown in the O flow diagram of FIG. 60, when it is determined whether or not to replace the drum,
If the drum is to be replaced, the drum characteristic number is set and the test key is turned on, after which the drum characteristic number is written in the drum characteristic No. area of the non-volatile RAM 107. Therefore, thereafter, the characteristics of the drum currently in use are always selected, and corrections are made based on this.

When the charge correction described above is performed, the charged potential of the photoreceptor is kept constant even if the temperature of the photoreceptor changes due to changes in the external environment or rise in temperature within the gas.
It is possible to prevent problems such as fogging due to a decrease in charging potential, a decrease in print density, or an increase in charging potential, and it is possible to always provide clear printing. Further, in this embodiment, by inputting (external setting) information classifying the humidity characteristics of the photoreceptor, correction is performed accordingly, so that temperature correction of charging characteristics can be performed with extremely high accuracy. Therefore, variations in the temperature characteristics of the photoreceptor itself can be alleviated, and the range of specifications for the photoreceptor can be expanded.

Next, the flowcharts shown in FIGS. 47 to 56 and the flowcharts shown in FIGS.
The operation of the entire apparatus will be explained with reference to the time charts shown in FIGS.

After the power is turned on, the door switch 129 is turned off.

The paper ejection switch 336 is OFF, the manual stop switch 328 is OFF, the bus sensor 123 is OFF, the temperature fuse 130 is not disconnected, and the paper ejection tray 3 is turned off.
84 is confirmed to be full (FULL), and it is further confirmed whether the mode is test print mode, maintenance mode, or replacement mode. If there is no problem, the MC relay 131 will turn on, and the fuser heater lamp 333 will turn on.
ON, the scan motor 312 turns ON and timer A (
TIMA) starts. When the timer ΔTIMA counts a predetermined time t1, mechanical parts such as the drum motor and developer motor are turned on, and then TrMA counts a predetermined time t1.
When counting 2, the laser 344 is turned on. T.I.
When time t25 is counted by MA, it is determined whether the laser is ready or not, and if yes (Y), then TIM
A = [26 is clocked and the transfer charger, laser, developer -[-tar, and developer sleeve bias are each 0F-
F, and when the time TIMA=t27 elapses, the drum motor, heat O-ra motor, static elimination lamp, and pre-transfer static elimination lamp are turned off. Next, at the timing of TIMA=t29, it is determined whether the scan motor is ready or H8YNC ready, and if YES (Y), TIMA is stopped (see FIG. 47).

Next, a determination of [Trayful in status 4] is made,
It is determined whether the toner bag is replaced or not, and whether or not there is no toner. If the tray is full, the tray full flag is set to 0' after paper is removed from the output tray, and the output tray counter is set. If it is a "toner bag replacement", the reset will be performed once the condition has returned to its original state.
In the case of toner replenishment, a reset is also performed at the stage of recovery. After passing through the above flow, it is next determined whether or not "Power Saving" is in progress in [Status 3], and if no (N), then "One sheet missing" in "Status 4" is determined. , if yes (Y), [cassette paper out detection ONJ]
If the answer is NO (N), the ``1 sheet out'' flag is set to 0', and if the ``fixer is ready'', the ``Status Waiting'' flag is set to O'. Next, IPRDYON,
IPREQON and whether it is "power saving" or not, "
If there is no problem, I
TMA starts. When TIMA=101, the registration motor 149 rotates in reverse, and when TIMA=t02, the registration motor 149 stops. At this stage, the leading edge of the paper is being held between the paper feed rollers.

Next, it is determined whether it is manual feed J or not, and if no (N), it is determined whether rlPRNT ONJ or not, and yes (Y).
If so, it becomes rIPREQ 0FFJ. Next, it is determined whether the timer E (T'IME> is in operation or not, and if it is in operation, it is determined that rTIME=t30, and the answer is yes (Y).
If so, it will be a TIME stop and transfer Sharjar 305
．． Peeling III Charger 306. Developer motor 141. The fixing devices 143 and 143 are respectively turned on.

If "rTIME=t30" is not found, TIME is stopped and the flow shifts to (2) (see FIG. 48).

Next, TIMA starts and plaid solenoid 158
turns on, and when rTIMA=t 1J, developer motor 1
41. Static elimination lamp 302. Pre-transfer static elimination lamp 303. Each of the drum motors 147 is turned on. rTIMA=
At t2J, the transfer charger 305. Fuser motor 143
becomes ON.

When rTIMA=t 3J, the peel charger 306 is turned on.
Then, when rTIMA=t4J, TIMA is restarted from 101. Next, it is determined whether the cassette is in the "manual feed" or not, and whether it is the upper or lower cassette. If it is the upper cassette, the paper feed motor 151 is rotated in the normal direction to feed the upper cassette, and if it is the lower cassette, the paper is fed after reaching rTIMA=t5J. Motor 151
Reverse the paper to feed the lower paper. Then rTIMA=t 5
Turn on the laser 344 when J, rTIMA=t
At 6J, the charger 304 is turned on.

rTIMA=t 7J checks whether it is laser ready or not, and if yes (Y), rV in "Status 1"
sYNc request" flag is set to 1'. Thereafter, timer B (TIMB) is started and the flow shifts to (2) (see FIG. 49).

Next, the paper feed motor 151 is stopped at rTIMA=31J,
rVsYNc command received” and select YES (Y).
If so, it is determined whether IT IMB<t 32J or not, and if yes (Y), TIMB is stopped, 1 page top and page end counters are started counting, and image writing processing is performed. Timer 〇, D (TIMC,
D> is started, and at f'T IMA=t 34 J, the TIMA is stopped and the paper feed motor 151 is stopped. Next, at rTIMc/D = t 35J, the registration motor 149 is rotated forward, total, and tJ counter 354 is ON, and rTIMC
/D=-136" to determine whether the toner concentration is high or low. If the density is low, the toner supply motor 159 is turned on.

[Next page end interrupt] is determined, and if yes (Y), an image writing end IPEND pulse is output. Set the stand counter to +1 and select "tray full", "drum replacement", and "developer replacement".

If it is "heat roller replacement", each status will be displayed.In addition, the determination result of "rVsYNc command received" is
If no (N), the charger 304 is turned off when rT'1MB=t46, and the laser 344 is turned off when rTIMB=t47J. Hack charger 304 OFF, I'TIMB
=t 47J and laser 344. Hakuli charger 30
6. Turn off each developer motor 141, rT IM
B=t 48J and transfer charger 305. The fuser motors 143 are turned OFF, and the drum motors 147 . Static elimination lamp 302. The pre-transfer static elimination lamp 303 is set to 0FF1 rTIMB=t 50'', and the blade solenoid 158 is turned off.

Also, in the flow of FTIMB<t 32J, -(N)
If so, then it is determined that IT IMB<t 33J, and if no (N>), TIMB is stopped and T1M△ is started.Then, the plaid solenoid 158 is turned ON, and r
At the stage of TIMA=tIJ, the developer motor 141. Drum motor 147. Static elimination lamp 302. Pre-transfer static elimination lamp 3
03 are respectively turned ON. and rTIMA=t2
When J, transfer charger 305. The fixing device motor 143 is turned on, and when rTIMA=t3J, the peeling charger 306 is turned on. Next, it is determined whether rTIMA-=t4J or not, and timer A is stopped by -H and restarted. The developer motor 141. Transfer charger 305. Hakuli Charger 306. Each of the fixing device motors 143 is turned on. "TIMA-15"
At 6J, the laser 344 is ON, rTIM=t. At 6J, the charger 304 is ON, rTIMA=t. At 7J, it is determined whether the laser is ready or not. If yes (Y), the TIMA
(Figure 50 above).

Next, it is determined whether the "toner full detection switch 126JOtl)' is ON or not, and if it is ON, a display is displayed. ”, and if it is not a manual feed, then it is determined that “specified cassette paper is out”, and if there is no paper, a display to that effect and a 5TPF (
Stop flag) is set to 1'. Next, timer E (TI
ME). If the stop flag is “1”, set the 5TPF to “O” and print ready IPRDY.
Turn off. If 5TPF is not 1, select ``Manual feed 1''.
”, and if it is “manual feed 1”, TIM
E-stop, manual stop switch 328 OFF
, manual feed O', TIMB stop, cassette paper out detection switch is determined to be ON or not. Next, the print request becomes IPREQ-ON, and the process shown in FIG.
The process moves to the flow (see above in Figure 51).

Next, the contents of the timer interrupt in each flow will be explained with reference to FIGS. 52 and 53.

This determines whether or not each of the timers A, B, C, D, and E is in operation, and when each timer is in operation, counts up. Read all input information in the port input reading part. Then, the timer is stopped at rT I MC/D = t 38J, and it is determined whether rTIME = t 39J. From then on, the operation of timer E (TIME) is continued, and at each time [toner replenishment motor 159J, r
"registration motor 149" is stopped. Then FTI
After "ME-14", it is determined whether or not "rTIMA is in operation" (this is to determine whether or not the next paper is to be printed). TIM if TIMA is operating
Stop E. After that, “TIME=t41J turns off the charger 304.

rTIME=t 42J and laser 344. Hakukuchaja 306. Each developer motor 141 is turned off. Transfer charger 305 with rTIME=t 43J
．． Turn off each fuser motor 143,
=t 44J, drum motor 147, static elimination lamp 302
．． The pre-transfer static elimination lamps 303 are each turned off (see FIG. 52).

rT IME=t 45J and plaid solenoid 158
OFF, TIME stop, determination of whether the fuser temperature is normal or not, determination of whether the fuser temperature is in the fuse stage, 1.1 scan motor 312 ready, or door switch 129 OFF, and each status is determined. Various processes are performed.

Next, the contents of the command interruption in each flow will be explained with reference to FIG. 54. When command interrupt processing is started, it is determined whether or not there is a "parity error", and if it is an error, the flag of the status DATA 81J becomes 1', indicating an "illegal command error". If it is not a “parity error”, the “status request” is SR1~
6, and if it is within the range, an output corresponding to one of them is generated. If it does not correspond to any of the "Status Requests", it is determined whether it is [Top/Bottom Margin], and if so, [Top/Bottom Margin] is specified and the "Status Set" is set to 1'.
Then, any one of rDATA21 to rDATA11 is specified. If it is not "Top/Bottom Margin", it is determined whether "manual feed designation" is specified, and if YES (Y), manual feed display and paper size display are performed next, and the paper size register is set. Then, when the manual feed status is set, the status becomes 1, and the rDATA41 J flag becomes "1'," and then the flow shifts to a flow where the paper out flag becomes 0' at status 4. If it is not "manual feed specification," it is determined whether or not it is "cassette specification." If 1 cassette is specified, the upper/lower display paper size is displayed, the paper size register is set, the manual feed status is reset, the status becomes 1, the DTA41 flag is set to O', and it is determined whether or not there is no paper in the cassette. If there is no paper, the flag will be 1'B.
If the cassette is not specified, it is determined whether the [select lamp is lit] or not, and the online select lamp (
It is determined whether the external device (for example, one specified by the host side) is lit, and if YES (Y), the select lamp is lit, and if the select lamp is not lit, it is determined whether the select lamp is off. If so, the select lamp turns off, and if )-(N), the process moves to the next flow.

Next, the flowcharts shown in FIGS. 55(A) to 55(C) will be explained.

In addition to the above-mentioned "shadow method", "power save" is included in FIG. 55(A), and if "power save" is in progress, the scan motor 312 is turned off.

Control the fuser to the power save temperature and set it to [Status 3 power save flag 1], and when power save is canceled, scan motor 312 is ON, fuser to normal temperature, [Status 3 power save flag 0]
”, and if it is [Image data transfer start], it is shown in Figure 55 (B
), the process moves to the flow of (C).

The paper size register is read, the top margin table data (Dl) of the specified paper size is read,
It is determined whether the top/bottom margin designation is 51Ill, and if NO (N), the top/bottom margin change table data D2 is read. Next, the calculation of top margin table data D1+margin change table data D2 is performed, and the contents of the top margin adjustment switch (442 in FIG. 14) are read. Next, the top margin adjustment table data D3 corresponding to the switch is read, the margin adjustment table data D3 is added to and subtracted from the values of Dl and (D1+02), and the calculation result D4 is set in the page top counter 278.

And bottom margin table data D for the specified paper size
5 is read and the top/bottom margin specification is 5++n
If it is NO (N), the top/bottom margin change table data D2 is read, the bottom margin table data D5 and the margin change table data D2 are subtracted, and the top margin adjustment switch is The contents of 442 are read, and the top margin adjustment table data D3 corresponding to the switch is read. Next, the margin adjustment table data D3 is added to or subtracted from the value of D5 or (D5-D2), and the calculation result D4 is set in the page counter 279. Next, the light margin table data D7 for the specified paper size is read, and a cassette/manual feed is determined. If the cassette is selected, it is determined whether it is the upper stage (reference) or not, and if it is not the upper stage, it is the lower stage, and the cassette upper / lower stage adjustment switch (Fig.
) and read the cassette upper/lower adjustment table data D8 corresponding to the switch. The D8 is added to or subtracted from the value of the D7, and the calculation result D9 or the D7 is set in the write margin counter 277. Also, if manual feed is specified, press the cassette/manual feed adjustment switch (
Read the contents of 440) in Fig. 14, read the cassette/manual feed adjustment table data 010 corresponding to the switch,
Next, the adjustment table data D10 is added to or subtracted from the value of D7, and the calculation result D11 is sent to the light margin counter 27.
Set to 7.

Next, left margin table data D1 for the specified paper size
2 is read, cassette/manual feed is determined,
If it is a cassette, it is determined whether it is the upper stage (standard) or not.
If it is not the upper stage, it is determined that it is the lower stage, the contents of the cassette upper/lower stage adjustment switch 440 are read, and the cassette upper/lower stage adjustment table data D8 corresponding to the switch is read. The data D8 is added to or subtracted from the value of the DI2, and the calculation result D13 or the data D12 is set in the left margin counter 276. If it is manual feed, the contents of the cassette/manual feed adjustment switch 441 are read and the cassette/manual feed adjustment table data D corresponding to the switch is read.
10 is read, addition and subtraction are performed between the data D10 and the value of the data DI2, and the calculation result D14 is set in the left margin counter 276.

The details of the cassette paper printing during the aforementioned flow are shown in the time chart of FIG. 57.

When the print start signal IPRNTφ (S65) is output, the print start permission signal IPREQφ (862) rises. After that, the developing device motor 141 etc. are turned on, and from time 14 to t
At gate 8, the paper feed motor 151 operates to convey the paper in the cassette. At this time, the laser diode 344 is turned ON at time t5, and data writing starts from time 7 (the diagonally shaded period from time 17 to time 11 is the data writing period). At time t9, the registration motor 149 rotates, and the data written on the photoreceptor is transferred to the paper. Data writing is performed until time tll when IPREQφ (862) falls, and after time t11 elapses, the registration motor 149 continues to rotate until time t12 and then stops. The laser diode 344 is then turned off at time t14.

FIGS. 58 and 59 are time charts for explaining the operation of printing on manual paper. In the following explanation, the differences from the case of printing on cassette paper described above will be explained.

In FIGS. 58 and 59, the paper feed motor 151 is not used, and the registration motor 149 is rotated in reverse to drive the feed @O-roller, which is used for paper conveyance, and the registration roller is driven by forward rotation. That's what I do. In addition, both of them receive the print start command IPREQ after receiving the "manual feed command".
φ (862) is made to rise. FIG. 58 shows a case where paper is set in the manual feed guide before the "manual feed command" is generated, and when the manual feed switch 326 is turned on due to paper setting, after that time t01
After that, the registration motor 149 rotates slightly in the opposite direction and stops with the leading edge of the paper added, and the ``1 manual feed command'' is issued.
At the time when PREQφ (862) rises, the registration motor rotates in the reverse direction again to transport the paper to the transfer position and then stops. Therefore, it is possible to print on paper from the cassette before issuing the "manual feed command".

The case shown in Fig. 59 is the case where the manual field switch 326 is turned on after the "manual feed command" is issued first, paper is set in the manual guide, and in this case, the registration is performed after a predetermined period of time [01 has elapsed. The motor 149 is continuously rotated in reverse to transport the paper to the transfer position. In addition, in either case, the manual stop switch 5328
The registration motor 149 is configured to stop at time t21 after a predetermined period has elapsed since the paper is turned off (time L 20'), but this causes the paper set in the manual feed guide to be held longer than the displayed size. Even "jam"
will not occur. In the case of cassette paper, such distribution is not necessary since the size is specified. Therefore, even if the cassette paper runs out, printing can be performed by preparing paper of a size larger than the size of the information to be printed, and it is also possible to use paper of a size that is not in the standard, allowing the device to usage will increase.

Flow (2) is a transition from the flow shown in FIG. 47 above.

The contents of (1) and (2) will be explained with reference to FIG.

When the test print mode is selected, the flow shifts to (2), and the print specified by the print mode No. is executed via the test key. When the maintenance mode is selected, the flow moves to ■, and the maintenance mode operation of No. specified via the test key is executed.
When the replacement mode is selected, the flow moves to @, and it is determined whether to replace the drum, whether to replace the developer, or whether to replace the heat roller.
"Developer replacement No. set", "Heat roller No. set"
The predetermined data is processed in the non-volatile RAM 107 via the test key.

FIG. 61 to FIG. 63 are correspondence diagrams showing correspondence between display numbers and respective contents.

(Hereinafter referred to as margins) [Effects of the Invention] As detailed above, the present invention forms a line in an area other than the area to be transferred to the paper every time a predetermined number of sheets are recorded, so the area where the line is formed The toner adheres firmly to the surface. Therefore, it is possible to prevent the formation of an area on the surface of the photoconductor where toner does not adhere for a long time, and furthermore, it is possible to avoid an increase in contact resistance when scraping off the adhered toner on the surface of the photoconductor with a cleaning blade. I can do it. Therefore, it is possible to prevent the surface of the photoreceptor and the cleaning blade from being scratched.

(Margin below)

[Brief explanation of drawings]

FIG. 1 is a system block diagram showing the relationship between the device and external devices in the present invention, FIG. 2 is a schematic sectional view of the print control unit (printer) in the system diagram, and FIG. 3 is the laser scanner unit in FIG. 2. FIG. 4 is a schematic diagram showing the paper feeding section in FIG. 2, FIG. 5 is a schematic diagram showing an example of the paper discharging section in FIG. 2, and FIG. 7 is an enlarged plan view of the display section in FIG. 6, FIG. 8 is a block diagram showing an example of the data control section in FIG. 1, and FIG. , FIG. 10, and FIG. 12 are respectively format diagrams of data handled by the data control section, FIG. 11 is a correspondence diagram of the areas of the recording section in the data control section and paper, and FIG.
14 is a detailed circuit diagram of each detector in FIG. 13. FIG. 15 is a block diagram showing details of the drive circuit and output elements in FIG. 13. Figure 16 is a detailed circuit diagram of the motor drive circuit and laser scan motor in Figure 13, Figure 17 is a detailed circuit diagram of the laser modulation circuit and semiconductor laser in Figure 13, and Figures 18 and 19 are semiconductor lasers. A characteristic diagram showing the relationship between the laser and the optical output, Figure 20 is the 17th
21 is a detailed circuit diagram showing the beam detection circuit and beam detector in FIG. 13, and FIGS. 22 and 24 are time charts for explaining the operation of the circuit in FIG. 21. FIGS. 23(A) and 23(B) are a front view and a side view showing an example of the structure of the beam detector,
FIG. 25 is a detailed circuit diagram of the print data write control circuit in FIG. 13, FIG. 26 is a circuit diagram of the interface circuit in FIG. 13, and FIG. Related (2) FIG. 28 is an explanatory diagram showing the contents of the status used in the device of the present invention; FIG. 29
The figure is a relationship diagram of the beam scanning position and data writing position on the recording photoreceptor in Figure 3, Figure 30 is a plan view showing the printing area portion of the entire surface of the paper including the paper size in Figure 29, Figures 31 and 32 are time charts for explaining the operation of the circuit in Figure 25, Figures 33 and 34 are print pattern diagrams printed on paper, and Figures 35 and 36 are time charts for explaining the operation of the circuit in Figure 25. FIG. 37 is a characteristic diagram showing the relationship between exposure position, exposure energy, surface potential, exposure energy, and exposure position to explain the exposure control operation in the circuit. 38 to 41 are characteristic diagrams for explaining the operation of the circuit in FIG. 37, FIG. 42 is a schematic diagram showing the relationship between the laser scanner unit and the recording photoreceptor in FIG. 2, and FIG. FIG. 44 is an explanatory diagram showing the relationship between the recording photoreceptor and paper, and FIG. 45 is a modification of the paper ejection tray shown in FIG.
), (B) and FIG. 46 are detailed diagrams of data recorded in each recording device in FIG. 13, a flowchart for explanation, and FIG. 57 to FIG. The time charts, FIGS. 61 to 63 are relationship diagrams showing display numbers and their contents in the apparatus of the present invention. 301... Recording medium, 30 = 1...
Charging means, 305...Transfer means, 307...
...Developing means, 311...Exposure means, 318.322. '327...Paper feeding means. -! Pull (Mad l Collie Figure 19 Shiguhiki Furnace Moda L Figure 43 4 (=i:j

Claims (3)

[Claims] (1) Charging means for charging the recording medium, exposure means for exposing the recording medium, developing means for developing the latent image formed on the recording medium, transfer means for transferring the developed image onto paper, one sheet. In a recording apparatus having a paper feeding means that takes out sheets one by one and supplies them to a transfer means, means is provided for forming an image on a portion of the recording medium other than the area to be transferred every time a predetermined number of sheets are recorded. A recording device characterized by: (2) Image formation in areas other than the area to be transferred to the paper on the recording medium in a direction perpendicular to the conveyance direction of the paper (only when the length is smaller than the maximum size) A recording device according to claim 1, characterized in that: (3) The recording apparatus according to claim 1, wherein the exposure means is performed by beam scanning.