JPS60235575A - Stabilizing device of laser light quantity - Google Patents

Abstract

PURPOSE:To stabilize the quantity of laser light and to reduce the failure rate of a semiconductor laser by turning off a switching means provided between a comparison output between a converted output of the semiconductor laser and an optical output setting reference voltage and an integration output in response to the said comparison output level while the laser is modulated and turning on it at a pre-period with no modulation or a part of the period. CONSTITUTION:The semiconductor laser diode 344 consists of a light emitting laser diode main body 259 and a monitor photodiode 260 being a photodetecting means monitoring the output beam intensity from the laser diode 259. A high frequency transistor 257 applies optical modulation of the laser diode 259. A drain D and a source S are brought into a low resistance of high speed analog switches 254, 255, 256 to provide modulation to the laser diode 259 when a high level voltage is impressed to a gate G and they ate turned on. When a low level voltage is impressed to the gate G, the resistance is higher conversely and they are turned off.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a laser light amount stabilizing device that stabilizes the optical output of a semiconductor laser.

[Technical background of the invention and its problems] In recent years, semiconductor lasers have been applied in various fields, and stabilizing the amount of laser light is an important condition in all fields.

In particular, when the optical output of a semiconductor laser is switched in multiple stages for different uses, stabilization of the optical output at the time of switching is an important issue. Furthermore, since semiconductor lasers are highly temperature dependent, a slight change in temperature can significantly change the optical output, making it even more difficult to stabilize the optical output.

Incidentally, semiconductor lasers have the property of being very easily damaged by abnormal current and voltage.

Conventionally, when stabilizing the amount of laser light, an abnormal current may flow or an abnormal voltage may be applied to the semiconductor laser, resulting in a high rate of damage to the semiconductor laser.

[Objective of the Invention] The present invention has been made in view of the above circumstances, and is intended to improve accuracy in stabilizing the optical output of a semiconductor laser, and to prevent failure of the semiconductor laser without causing abnormal current to flow during stabilization. It is an object of the present invention to provide a laser light amount stabilizing device that can significantly reduce the rate.

[Summary of the Invention] In order to achieve the above object, the present invention detects the optical output of a semiconductor laser, converts this optical detection output into a voltage proportional to the optical output, and compares this converted output with an optical output setting reference voltage. and performing integration according to this comparison output level, supplying a current proportional to this integrated output to the semiconductor laser,
A switching means is set between the comparative output and the integral output, and the switching means is set to 0FFL while the laser is modulated, and the switching means is set to ON during the previous period or a part of the period when the laser is not modulated. This stabilizes the amount of laser light.

(The following is a margin) [Embodiment 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 a laser beam. Host-side system 1 that provides information (electronic computer, wordbook
information from the processor body, etc.) is given to the data control unit 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 10.
Send to 0.

The print control section 100 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; 305 is the photoreceptor 30f;
A transfer charger 306 is used to transfer the toner developed on the photoconductor 1 onto a sheet of paper, and a peeling charger 306 is used to separate the sheet after the 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; 310 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 312 scans and modulates a laser beam onto the photoreceptor 301 for recording.
01, an octahedral polygon mirror 313 for rotating the polygon mirror 312 at high speed;
A scan motor 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 31;
This is a reflecting mirror for guiding the laser beam from one side 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 for detecting that there is no paper in the upper cassette 317; and 320 is provided in the upper cassette 317. , an upper cassette rise detection switch consisting of 4 bits for detecting a mark for size identification. 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; 327 is a manual paper feed roller that conveys the paper after the insertion is confirmed by the manual feed switch 325; 32
Reference numeral 8 denotes a manual stop switch that detects the paper fed by the manual paper feed roller 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 9-mister 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 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 unit that generates DC voltages used for each control; 340 is a P unit that controls the printer 300;
This is a C plate unit.

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

FIG. 3 is a perspective view showing an outline of a portion for recording information on the photoreceptor 301 using a laser portion. In Figure 3, 1. The laser beam emitted from the semiconductor laser 344 is corrected into parallel light by the collimator lens 343, and the parallel light is applied to one surface of the octahedron of the polygon mirror 313. The polygon mirror 313 is
Since it 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 f/theta lens 314 and scans the beam scanning range 348 from left to right. A portion of the laser beam within the beam scanning range 348 is guided by a reflecting mirror 345 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. Furthermore, the laser beam that is not incident on the reflection mirror 345 within the beam scanning range 348 is
The photoreceptor 301 is irradiated with light. Photoreceptor 301 in Fig. 3
The location where the upper laser beam is scanned is shown at 349. 3
04 indicates a charging charger, and 347 indicates paper.

As shown in FIG. 2, in an actual printer, the laser beam that has passed through the f/theta lens 314 is not directly irradiated onto the photoreceptor 301, but is reflected by reflection mirrors 315 and 316. However, in FIG. 3, for convenience, reflection mirrors 315 and 3 are shown.
16 is not shown in the figure, and the laser beam that has passed through the [.theta. lens 314 is shown to be directly irradiated onto the photoreceptor 301.

Here, the configuration of the reflecting mirror 345 will be explained with reference to FIG. 42. As shown in the figure, this reflecting 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.

As is clear from FIG. 2, the laser scanner unit shown in FIGS. 3 and 42 is shielded from the outside to prevent the scanning beam from leaking. 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 bus 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 fed along the paper guide plate to the registration roller 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 the light does not enter the registration roller front bus sensor 394, so that the fed paper can be confirmed. Furthermore, if the paper is not fed correctly, the paper does not reach the position of the registration roller front path sensor, and the light from the light emitting diode 393 continues to enter the registration roller front bus sensor. ,
It can be recognized that 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 such a non-reversing type is used, the first printing paper is on the bottom side, so the information delivery device (host system 1) has to send data from the last page, so the host There is a drawback that the method of filing information in 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, 385 is a paper stopper that can be slid according to the length of the printing paper in the conveyance direction. 388 is a paper holding actuator to prevent the paper stored in the tray from floating; 395 is a paper ejection switch to confirm that the paper is properly stored in the tray 384; and 391 is the presence or absence of 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 irradiated with light, and when there is no paper 390, the tray sensor 392 is irradiated with light, so that the presence or absence of the paper 390 can be detected.

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 3 which is a separating means.
89 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 the actuator 388, the position al is "full of paper", the position a2 is "with paper", and the position of a3 is "without paper". The separating means 389 is arranged so that at least the paper 390 is separated from the paper output tray 384.
While the actuator 388 is being ejected and moved inward, the actuator 388 is separated;
When paper should be detected, for example, during a printing operation or when it is stopped, the solenoid 389 is turned off in synchronization with the status signal at that time, and the 1Ill interval of the actuator 388 is released, and the detection operation is performed. . For this reason, paper 3
The discharging tip 90 will not collide with the actuator 388 (and the discharging operation will not be hindered).

Note that each sheet of paper fed into the paper ejection tray is detected by a paper ejection switch 395, 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. When the number of grooves reaches 1, it is displayed on the tray full lamp 35B in FIG. 6, and the memory counter is cleared.

FIG. 6 is a detailed diagram of the operation panel of 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.
If a paper jam or toner replenishment occurs, open it in the direction of the arrow and process it. Further, the maintenance cover 352 is
Although the front cover 351 has a structure that can be opened from the top, it cannot be opened unless the front cover 351 is opened in the direction of the arrow, to prevent the operator from operating incorrectly.

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 a power lamp that indicates that the printer 300 is powered on. , 358 is a tray full lamp that indicates that the inverted tray unit 381 is full of printing paper;
9 is a color LCD that displays details of the printer's operating status.
Each indicator is shown below. The total number 353 to LCD display 359 described above are constantly operated or displayed. Next, the maintenance cover 35
I will explain the parts that cannot be operated unless 2 is opened. The following parts are operated only by servicemen.

403 is a maintenance cover for selecting maintenance mode and replacement mode, and 406 is an indicator lamp indicating that the system is in maintenance mode.

407 is an indicator lamp indicating that it is in exchange mode;
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 the volumes 360 and 361 are structured so that they can be turned by inserting an adjusting screwdriver, and cannot be turned by hand with the maintenance cover 352 open.

FIG. 7 is a detailed diagram of the LCD display 359,
The functions 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 373 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 cassette 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 bag (not shown) is full of toner collected by the cleaning blade 310 in FIG. 376
decreases when the toner dropper (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. 37
9 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 A4 vertical paper cassette, A4-R lights up, and if 86 is selected in the manual feed mode, 86 lights up. 363 lights up when the lower cassette is selected, 364 lights up when the upper cassette is selected, and 365 lights up when the manual feed is selected. 366 is printer 3
It represents the shape of 00 and is always lit, 367 is the photoreceptor 3
01 is always lit, 368 is printer 300
369 is always lit except when the conveyor is jammed, and 368 is alternately lit when the conveyor is jammed (when 374 is blinking). 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 post-side system 1 into a dot-compatible page memory 20 corresponding to the printing area on the paper of the printer 300. Further, the stored data on the page memory 20 is sent to the printer 300 to perform a printing operation.

The data control unit 2 is configured to accept two types of information. One is character code information LJIS
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 as it is in page memory 20 times. Hereinafter, an overview of the data control section 2 will be explained with reference to FIG.

Information from the host system 1J is sent to the interface 50 via the signal line S01, and the information is stored in the data latch 3.

Signal line S between interface 50 and host system 1
O2 is sent from the host system 1. A data strobe signal and other control signal line 803 are a busy signal and status signal line from the data control device.

The format of the information sent from the host system 1 is shown in FIGS. 9 and 10. The format example in Figure 9 is the format e1 for character code information, character identification code indicating that it is character code information, and paper size data indicating the size of the paper to be printed at the beginning of one page. It's in.

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. In addition, one line of characters] - code data is a code indicating the character size, characters] -
It consists of a code and an LF code that indicates the division of one line of data.

FIG. 10 shows a format for image information, in which an image identification code indicating the image information and a paper size identification code indicating the size of the paper on which printing is to be carried 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 one line of data is specified by the paper size identification data, it is automatically determined on the data control unit 2 side by counting the specified data. 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, the case of character code information will be described. When the character identification code shown in FIG. The main control unit 6 determines that the input information is character]-code information, and instructs the distributor 4 via the signal line 306 to input the next paper size data to the page code buffer 1 control circuit 7. Command zuru. Therefore, the paper size data is input from the distributor 4 to the page code buffer 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. At this time, the character code data is stored in the memory area on the page code buffer 9 designated by the address counter 8. When the input of one page's worth of characters into the page code buffer is completed and the E N I) code in FIG. 9 is detected by the decoder 5, the signal line 305 and $09 produce
Main control unit 6. Each of the END code detections is transmitted to the base code buffer 1 control circuit 7. By signal line SO9,
When the page buffer control circuit 7 confirms that input of character codes for one page into the page code buffer 7 is completed, the data is stored in the page memory 20 in units of dots.

FIG. 11 shows the correspondence between memory space and paper on the pager 20. 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 internal address counter 18.
．． 0) points are shown. 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 (A3VE) of A3 size paper, 47G, tA49-size vertical 7
48 represents an A5 size vertical address <A5VE). 33 is A size vertical address ADRV-〇, horizontal address ADRH-A311F point ADR (0, A3HE), 34 is A size in the same way.
DR (0, A4HE), 3'5 is ADR (0, A311
F) are shown respectively. Also, 36 is A3 size vertical at L/S ADRV = (A3VE), horizontal 7 dress A
D RH'=O point ADR(A3VE.

0) and 37 are ADR (A4VE, 0) in the same way.

38 indicates ADR (A5VE, 0), respectively.

39 is the A3 size vertical address ADRV=A3VE,
Horizontal address A D RH = A 38 Point ADR (A3VE, A3HE) of E, similarly 40 is A
DR(Δ4VE, A41-IE), 41 is ADR(A
5VE, A5HE) respectively.

Storing a character pattern as a dot image in the page maker 20 having the above-mentioned memory space is performed as follows. The character size data of the first line is read from the page code buffer 19 to the page code buffer control circuit 7 via the signal line S10. The type of character size in this embodiment is basically 211 font of 40x40°32x32 dots, and the page code buffer 1 control circuit 7 determines the character size based on the read character size code and sends the determination signal as a signal. It is sent to the page memory control circuit 17 via a line 811 and to the character generator 15 via a signal line S13. The page memory control circuit 17 controls the line feed pitch and the character pitch based on the character size determination signal, and the character generator 15 switches the character rise area.

The character code of the character size data is stored in the line address counter 11 in the line buffer 10 which has the 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 y10 is completed, the line address counter 11 returns to the initial address (0). First, the page memory 20 of the first vertical line of the character font (line 57 in Figure 11)
Writing is performed.

Here, the line/scan counter 13 has an initial value (0,
O), and the write address counter 18
The value of is ADR (0, 0>. Row buffer 10
The character code data is sequentially read out at a constant cycle starting from the first digit, and latched in order into the output block 12 in order to synchronize with the line counter 13. When the first character code (character 'T' in this embodiment) is latched into 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 pattern selection code of the character generator 15 is generated. is input to the character generator 15 as follows. Here, the configuration of the line/scan counter 13 will be explained.
-L 6 bits are a counter that counts scanning lines, that is, a counter in the vertical direction of the character pattern, and in the case of a 40 x 40 dot character, it counts from 0 to 39 plus, line feed pitch control 942 minutes, and 0' Return to

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 spacing between characters is 8 bits and the vertical spacing between nine characters is 8 bits will be described. As mentioned above, the first character code (“
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, the value of the line/scan counter is (0, 0), so the character generator 15 outputs the data (8 The output data of the character generator 15 is output 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 internal application address counter 18 is ADR (0, 0), it is written to the vertical address '0' and the horizontal address '0'. Then, when writing of the 1-byte character pattern is completed, the value of the line/scan counter is (0, 1
>, and the value of the write address counter 18 also changes to A.
Changes to DR(0,1). Therefore, the output of the Gyara-Kutaj I generator 15 is 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 transferred to the page memory 2.
ADR of 0 (written at address 0, 1>) In this way, the last (
When the writing of the data (4'4' data) is completed,
The value of the line/scan counter is (0, 5>, and the write address counter 18 is ADR (0, 5>). Since the horizontal spacing between characters is 8 dots (1 byte), the character generator The output of 15 is forced to 0 by a command from the page code buffer control circuit 7.
', and 'o' is written to page memory address 2° (7) ADR < 0.5). After the write operation is completed, the row address counter is incremented by '1' and the next character code is read from the row buffer 110. is set in the output block 12. Also, the line/scan counter is (0, 0>), and the write address counter 18 is ADR (0, 6). Therefore, the next one is 0'
An operation is performed to write the data of the 101st line in the vertical direction of the character pattern into the page memory 20. At this time, the write address counter 18 is ADR (0, 6>, (0, 7>,
<0.8), (0°9), and (0, A) are sequentially counted up, and the character pattern data of each O is written to the address specified by the old address counter 18.

If the value of address counter 18 for writing is (0°B)
, when the value of the line/scan counter 13 becomes (0°5), O° is written into 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.

Also, the line/scan counter 13 is (0°0), I
The embedded address counter 18 becomes ADR (0°C).

In this way, the character pattern data of the 'o'-th line in the vertical direction is sequentially written into the page memory 20.
Then, when the '1-F' code is output to the output of the row buffer 110, the 'L F' code detection signal is sent to the output line 81.
4 to the page code buffer 1 control circuit 7, and the aging operation of the character pattern from the character generator 15 is stopped. After that, the write address counter 18 is sequentially incremented by 1' and 0' is forcibly written into the page memory 20. If the value of the write address jy counter 18 is currently designated as A3 size, then the value of ADR (0, A3HE), ie, the value of FIG.
At the point, after the forced "0" write operation, the write address counter 18 is set to ADR (1, 0), the row address counter 11.18 (0), and the line/scan counter 13 are set to (1, 0>). Then, T', which is the first character code from the line buffer 10, is set again in the output latch 12. Then, the character pattern data of the 1' vertical line of the character pattern is written to the page memory 20. .In the same way, vertical direction '2' of the character pattern.

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

The line/scan counters 13 are set to (2B, O), respectively. This completes the writing operation of character pattern data for one line, but next, since the line feed bit is every 48 lines, 0' is forcibly written into the page memory 20 for the remaining eight lines. When the self-writing of 0' for 8 lines is completed, the address value of the write address counter 18 is set to point 1' in FIG.
At (30,0), the row address counter 11 is (0).

The line/scan counters are each set to their initial values (0, 0>). This completes all the operations including the line feed pitch for one line. Character]-code data is transferred from the page code buffer 9. When the transfer of character]-code data is completed, the line address counter 11 returns to the initial address (0). After that, the same process as writing the character pattern data on the first line is performed. The character pattern data of the second line is filled in by the operation. Therefore, when the writing operation of the character pattern data of the second line is completed, the address value of the write address counter becomes ADH (60, O), and the row address counter 11 is (O
), the line/scan counters are set to (0,0), respectively. In this way, the character codes of each line are sequentially patterned and the pattern data is written onto the page memory 20 in step Iυ. 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 control circuit 7 forcibly sets the output of the character generator 15 to 0' via the signal line 813, and 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 1-IE)). and the 11th
0' is written to the point in FIG. 39, and the entire operation of writing character pattern data for one page of the specified paper size to the page memory 20 is completed. Then, the C write address counter 18 is ADR (0, 0), the row address counter 11
is (0), line/scan counter 13 is <0.0)
All are initialized to .

Next, a case where the data sent from the host system 1 is image information will be described. Image identification in FIG. The signal is input to the main control unit 6 via 805. Main control section 6
Then, it is determined that the input information is image information, and a command is given to the distributor 4 to input the next paper size data to the page memory control circuit 17 via the signal line SO6.

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 315.
is man-powered. 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 ΔDR(0,0)) in FIG.
The write address counter 18 is set to ADR (
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, ie, °A48E'. Naturally, the length of the image information per line sent from the host system 1 is 'A48.
E', so image data 19 image data 2 in FIG. ...The data length of the image data m is 'A4VE'
', and 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.
To 32 points ADR (0,0)/34 points ADR
(0°A4HE), image data 2 is a 51 point line, image data 3 is a 52 point line...
Image data m is a line of 37 points, so the final address is 40 points ADR (Δ4VE, A4HE). Image information is written into the page memory 20 while controlling the write address counter 18 in this way.

The character pattern data 13 written in the page memory 20 in this manner is sequentially outputted to the latch 21 . Gate circuit 23: Sends data to be printed to the print control section via the interface bus S17 through the interface chair 22. In FIG. 8, S17 is a status data line from the print control unit, 818 is a command data line for specifying the operation mode to the print control unit, S19 and 820 are strobe signal lines when sending command data and print data,
S21 is a high signal line from the print control unit, S22 is
A horizontal synchronization signal line from the print control unit, 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 unit, S2> is a print request signal line that indicates that printing is possible, 826 is a select signal line (2 lines) that specifies the data content of the data line in the interface bus 817;

S27 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 section, printing from the data control section 2 is started via the start signal line S27.
In response, the print control section sends a horizontal synchronization signal S22.

This horizontal synchronization signal 822 first sends out each data of the 32-point line in FIG. The horizontal synchronization signal S
22, the address is sequentially changed line by line, and the page end signal S2 from the print control section is sent.
This operation is repeated until the page end signal 823 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 823 is received, the data sending is forcibly stopped. In the print control section, the page end signal 323 is output at the same timing as the horizontal synchronization signal 822. Also, the 11th
The correspondence r with the memory address in the figure is output from the print control unit at a timing that is equal to or earlier than 46 points for the last line A3 and 47 points for A4 in the memory area of the paper size.

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 shown in FIG. In FIG. 13, 101 is the print control section 10.
A microprocessor 1102 for controlling each unit in the microprocessor 1102 is an interrupt control circuit for controlling interrupts to the microprocessor 101, and a command signal line 830. Page end signal line S29 from the print data backfill control circuit 19.
Interrupt request signals from each of the timeout signal lines 828 from the general-purpose timer 103 are sent to the microprocessor-1.
Tell 01. A general-purpose timer 103 generates basic timing signals for controlling paper conveyance, drum rotation, etc. In this embodiment, this general-purpose timer 103 has 1
It is set to 0m5ec. A ROM (read only memory) 104 contains all control programs for operating the print control section 100. 10
5 is the same ROM and contains a data table different from the ROM 104. The contents of the data table are
This is shown in Figure 5 (A). In FIG. 45(A), the address (
4000, 4001) are top margin control data for paper size A3.

Addresses (4002, 4003) are bottom margin control data, addresses (4004, 4005) are left margin control data, addresses (4006, 400)
7) respectively contain write margin control data. Similarly, the addresses (4008 to 400F) include top, bottom, left, and
Contains data for controlling each write margin. The following address (4087>) contains margin control data corresponding to various paper sizes.These margin control data are set data for the margin control counter in the print data write control circuit 119, which will be described later. used as.

Addresses (4100 to 41FF) contain a table of command codes for specifying operations from the data control section 2, and are used for checking command codes from the data control section 2. The content of the command is a top/bottom margin change table.

These include a top margin adjustment table, a current upper/lower adjustment table, a current 1 to 5 manual feed adjustment table, and the like. From addresses (4200 to 42FF), the photosensitive drum 301
It contains data on the charging characteristics of , and five types of data A-'-F. This data is used for thermal correction control of the charging charger 304, which will be described later.

The address (4300 to 43FF) is an exchange data table, and the photosensitive drum 301. Developer 307
It contains cycle data for the developer and 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 (IM) A as shown in FIG.

Contains a paper size register B, . . . , E1 (which stores cassette 1 noise data generated by signals from cassette size detection switches 320 and 324, which will be described later), a status register 6, and other contents. The microprocessor-101 compares the cassette size stored in the paper size register with the size of recording information (both-edge data, etc.) from an external device sent from the data control unit 2,
If the cassette size is larger, the printing control section 10 in the latter stage
A print operation command is issued to 0. 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. 107
is a non-volatile RAM, and the data in the memory is retained even when the power is turned off. Further, the data contents in the nonvolatile generation RAM are shown in FIG. 45(B). Figure 45 (B)
Address (6000) contains the drum characteristic number input from the operation panel in the exchange mode, and address (6100) contains the jam information when a jam occurs. This is used to prevent forgetting to dispose of jammed paper inside the machine when the machine is turned off. The address (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 is delivered to the reversing 1-ray 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. Additionally, the paper output tray counter is automatically cleared when paper is removed from the tray by the operator. Therefore, even when the power is turned off, the number of sheets remaining in the tray is kept 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 (△), the operator is informed to replace the drum by the display on the operation section.

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

Address (6500) is a fixing roller replacement counter, which is incremented by 1 for each print as in the case of drum replacement, and when it reaches the value in the replacement table (fixing roller) shown in FIG. 45 (A), the counter displays J Ru.

108 is a power supply sequence circuit, and the non-volatile generation RA
MI 07(7)t101117￥1. Electric 1OFFR
It has the function of preventing erroneous operation. 399 is a power supply device that supplies power to the control section. Reference numeral 110 denotes an input/output boat 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. Reference numeral 116 indicates driving elements such as a motor, a high-voltage power lamp, a solenoid, a fan, and a heater.

115 is a drive circuit C' for the drive element 116; 11
4 is an output port that provides an output signal to the drive circuit 115. 312 is a laser scan motor for operating the laser beam, 118 is its drive circuit,
Reference numeral 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 controls writing to the test pattern and generates test pattern print data. 122 is an interface circuit that controls output of status data to the data control section 2, reception of command data and print data from the data control section 2, and the like.

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 the multiplexer, an 8-bit signal S32 is inputted to the input port 112 in FIG. 13 by the eyelid signal S31.

320 is an upper cassette size detection switch;
It consists of several 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 cassette 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. This sensor is
A bias voltage is applied through a resistor L13 (not shown), and the output voltage changes depending on the presence or absence of paper. Therefore, by inputting the output to the comparator 124 to which the M quasi-voltage yre[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 at the fixed @0-ra portion, and 395 indicates a paper ejection switch located at the paper ejection tray portion. Reference numeral 125 indicates a toner out detection switch for detecting the absence of toner in the toner box, and 126 indicates a toner full detection switch which operates when the toner bag becomes full.

127 is a detection sensor (with a developer toner ratio of 11 tl).
The probe H3T detection sensor) uses a photodiode. 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 O is obtained when the toner*i is above or below the specified value. It will be done.

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. One of the temperature fuses 13 and 0 is connected to the +24VA power supply, so if the temperature fuse 130 is blown due to an abnormality in the fixing unit, the MC relay 131 is turned off and the drive power is turned off.
It will be FF. Further, the temperature fuse 130 is connected to a resistor R01, and one end of the resistor RO1 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 is blown, the input of the comparator 132 becomes Ov. Therefore, the temperature fuse blown detection signal is output as the output of the comparator 132. 133 is a destination selector switch, and specifically, The ON state is for domestic use (A and B size), and the OFF state is for US use (Saugal, letter size) due to the 0N10FF of this switch. Even if the combination of paper size is the same, the paper size for domestic or US paper size is selected depending on the state of this switch.

134 is a Gillem reset switch, which is installed inside the front cover. This switch is turned ON to confirm that a paper jam or toner bag is full after the operator clears the jam or replaces the toner bag. It is a switch that can be used. 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 shown in FIG. 5 that detects waste in the tray. 33
A thermistor 4 detects the temperature of the fixing device, and is controlled so that the temperature detected by this thermistor is constant. The output of thermistor 334 is connected to resistor RO3 and comparator 136.13.
It is connected to the input side of 7. Therefore, the input voltage of the comparator changes as the resistance value of the thermistor 334 changes due to temperature.

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 and RO7 is applied, and the output of the amparator 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) 83, the comparator 13
The reference voltage of 6 is lowered by resistor RO8 and the temperature control of the fuser is lower than when transistor 138 is at 0FFL. Therefore, the power consumption of the fixing device becomes low and the fixing device enters a power save state. Also, comparator 1
The reference voltage No. 37 is given by the voltage division of resistors RO4 and RO5. Since the reference voltage of this comparator 137 is set considerably 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 failure of the heater drive circuit during printer operation. can. The output 833 of the comparator 136 is input to a multiplexer 139 and read by the microprocessor 101. Note that this input signal is used to detect the ready state of the fixing device. Further, it is used as a drive signal for the fixing device heater lamp 333 in FIG. 15.

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/[) converter 271 and read by the microprocessor 101 through the multiplexer 139. This A/D converted data of the photoreceptor 301 is used for charge correction of the photoreceptor 301, which will be described later. 44
0 is a cassette bottom/lower adjustment switch, 441 is a cassette/manual feed 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 denotes a driver for the developing device motor, which performs P and LL sub-control. 143 is a fixing device motor, and a DC-driven Hall motor is used.

142 is a driver for the fuser motor 143;
Put control is being performed. 145 is a fan motor for cooling the inside of the machine, and a C-driven Hall motor is used. 144 is a driver for the cooling fan motor, which is similar to the developer and fixing device driver described above;
L, L speed control is not performed. Reference numeral 147 is a motor for driving the photosensitive drum 301, and a four-phase pulse motor is used. 146 is a driver for the drum motor 147, which employs a constant current 1-2 phase excitation system. The speed is approximately 1200 PPS, which is the speed at which vibrations are less likely to occur. 149 is the registration roller 329
and a registration motor that drives the manual feed roller 327, which is a pulse motor. 148 is a driver for the registration motor, which uses a constant voltage two-phase excitation system.

The speed is about 400PPS.

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, forward and reverse rotations 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 EDs. RIO is a current control resistor for the static elimination lamp 302, and 152 is a driver for the static elimination lamp 302.

Is 303 transcription chi 1? - It is a pre-transfer static elimination lamp placed in front of the transfer chamber to increase transfer efficiency.
). R11 is a current control resistor for the pre-transfer static elimination lamp, and 153 is a driver for the pre-transfer static elimination 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. 159 is 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 gutter hopper to the developing device 307;
Replenish toner. The operation of the toner replenishing motor 159 changes depending on 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 charge V 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,
A high voltage output 0N10FF signal line 835 and an analog control signal line S36 for changing the high voltage output current are connected to the input of the charging high voltage power supply. Further, the analog control signal 1iS36 is connected to the D/A converter 165, and the D/A converter 165 is
converts it into an analog voltage and controls the output current of the charging high-voltage power supply. 306 is chi 1 for peeling? - The peeler charger 306 is connected to the output of the high voltage power source 161 for peeling. The high-voltage power source for peeling has an AC output. 305 is a transfer charger for transferring the developed toner on the photoreceptor 301 onto paper; a transfer charge iν;
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, one side of which is connected to one side of the A'C 100V power source.

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 833 and 839 are input to 66, and S33 is the thermistor 33 in the fixing device 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 31 in Figure 13.
2 is a detailed circuit diagram of the drive circuit 118 of FIG. In FIG. 16, 312 is a circuit diagram inside the laser scan motor. LO2, LO3, and LO4 indicate motor coils, and 180.1si and 182 are Hall elements that detect the position of the motor rotor, respectively. 183,184
．． 185 is a comparator for the Hall elements 180, 181, and 182, and its output is connected to the motile 102. It is connected through resistors R26, R27, and R28 to the bases of power transistors 171, 172, and 173 that drive LO3 and LO4. Furthermore, base resistors R23, R24 are connected between the bases of the power transistors 171, 172, 173 and 1 mitter.
, R25 are connected to each other. As the rotor of the motor rotates, the Hall elements 180, 181, and 182 are turned on in the order of 180, 181, and 182 (7).

Therefore, the outputs of comparators 183, 184, and 185 are also 1.
The level becomes LOW in the order of 83, 184, and 185. Therefore, the power transistors are turned on in the order of 173, 172.171, and 1-02. LO3゜[In the order of 04, drive I Fl
Ill? ! The application of pressure causes the laser scan motor 312 to rotate. Furthermore, the output of the inverter 185 is inputted to the frequency division counter 175 through a diode DO2, a resistor R30 and a waveform shaping circuit including a capacitor Go (3) and an inverter 174. The output of Q2 is connected to motor speed switching gates 176 and 177, and the output of the speed switching gate passes through an OR gate 178 to the F of a PLL (phase, lock, loop) control IC.
Connected to G input. Also, one input of the speed switching gate 176177 has a speed control signal line S4.
0 output and its inverted output are connected. Therefore 3
When 40 is at LOW level, the switching gate 177 is enabled and the output of 01 of the minute/period counter is controlled by the PLL control 1.
When S40 is at HIGH level, the switching gate 176 is enabled, and the output of the frequency division counter 175'Q2 is inputted to the FG large input of the PLL control IC 167. Here, to briefly explain the input/output signals of the P[-1-control IC 167, the P/S terminal (PI-A
Y/5TOP) stops at HI GHL/bell, L
It will start at OW level.

In the case of HIGH level, the common power of both terminals of AGC and APC becomes HIGH 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 the crystal reference frequency division output signal, CPIN is the reference frequency input, and LD is the lock detection signal.When the motor rotation speed is within the lock range, it is at I''IGH level, otherwise it is 1-O.
The W level is displayed. AFC is the output of the motor's speed control system and is the output of the 8-bit D/A converter inside the PLLIC, and APC is the output of the motor's phase control system.
This is the output of the 8-bit D/A converter inside G. Also P
-X01 connected to LL1c167 is a crystal resonator for generating a reference frequency, and COI and GO2 are capacitors for oscillation.

The output terminal of the PLL control IC 167 (7) AFC, APC+7) constitutes an adder circuit with resistors R12 and R13, and is connected to one side input terminal of an operational amplifier 168. A voltage obtained by dividing +12■ by resistors R14 and R15 is applied to the child input terminal of the operational amplifier 168. Also, resistance R1
6 and capacitor υco3 constitute a negative feedback circuit, and in particular, capacitor C03 serves as a bypass filter. Therefore, the amplification section of the operational amplifier 168 has a characteristic of attenuating inputs having a certain frequency or higher. The output of the A amplifier 168 is connected to the input terminal of the pulse width modulation type switching regulator 1C169. 16
9 is a commercially available pulse width modulation type switching regulator IC. This IC 169 and power transistor 170. The diode DO1, the diode L-01, and the capacitor CO5 constitute a down switching regulator circuit. In the input/output of the TC1690, one terminal is a comparison reference voltage terminal, and a reference voltage obtained by dividing the voltage of the reference voltage output terminal VREF inside the TC169 by resistors R17 and R18 is applied. The DEADT IME terminal regulates the maximum pulse width of the output, and a voltage obtained by dividing the VREF by resistors R19 and R20 is applied thereto. CI and C2 are output terminals, and the pulse width changes depending on the voltage value of the input terminal. In other words, if the - input terminal voltage is lower than the input terminal voltage on one side, C1, C2
The path width on the LOW level side becomes smaller, and the width at which the power transistor 170 is turned on becomes smaller as well.

Therefore, the voltage across the capacitor CO5 also becomes smaller.

Moreover, 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 CO5 also becomes large.

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

When the rotation start signal S42 of the scan motor 312 becomes LOW level, the AFC of the P'LL control LC1'67,
Since the Ryokawa power of the APC is at the LOW level until the aforementioned lock signal S41 is output, the operational amplifier 16
8 outputs a HIGH level voltage.

Therefore, the output pulse width of the regulator l0169 becomes large, and the voltage across the capacitor CO5 becomes about -1-16V. Then, at a position where the rotor of the motor is stopped, the Hall elements 180, 181 . '182 is ON, so motor coil +02. L03
, LO4, the Hall elements 180, 181.1.8
The coil corresponding to No. 2 is excited, and the scan motor 312 starts rotating. Then, the scan motor 312 speeds up its rotation. The level of the speed control signal line S40 is now Hr.
Since it is G1-1, the Q2 output of the frequency division counter 175 is applied to the FG input terminal of the PLL control IC 167. Therefore, the frequency division counter 175 functions as an 8 frequency division circuit. The frequency of the signal applied to FGIN is P
When reaching approximately 96% of the reference frequency inside LLIC169, the lock signal LD841 becomes HIGH and AFC,A
PC output L/to/l, t, t L OW L/bare L, (OV) is not fixed (but is switched to the output voltage of the PLLIC internal D/A inverter. Therefore, from now on, the speed control system output The scan motor 312 is controlled to a constant speed by the 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 8 minutes 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, during printing operation, that is, during high-speed rotation, approximately 12. OOOrpm, approximately 6000 during standby
rp! It is Il.

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 that monitors the intensity of the output beam from the laser diode 259. Reference numeral 257 is a voltage-current converting means (or first current driving means) C that performs optical modulation of the laser diode 259 using a certain high frequency transistor. Resistance R
50 is a current detection resistor, 258 is a laser diode 2
59 is a transistor which is a second current driving means for flowing a bias current, and R51 is its current limiting resistor, R59.
52 is a base current limiting resistor of the transistor 258. 254, 255, 256 are laser diodes 259
A high-speed analog switch is used to give modulation to the gate (G).
When a level voltage is applied, the drain (D), source (
S) becomes low resistance and becomes ON state. When a voltage of -0W level 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 one is for increasing the print density of one dot line with the output P (SH) between the first output P (ON) and the second output P (OFF) (7), and the analog switch 255 is set to 01. As a result, the laser diode 259 has the output P(
St-1) (rough correction of P (SH) will be described later).

Resistance R/12. R43 is an analog switch 254°25
5.256 (7) Short circuit protection resistance when ON10FF changes,
249, 250, 251 is the analog switch 254
, 255, 256 gate drivers. CO9,
C10 and C11 are speed-up capacitors,
R47, R48, R49 are the gate drivers 249
, 250, 251 input resistances.

246 is a 3NAND gate, and when all three gate inputs are at -110H level, the output becomes 10W level, turning on the analog switch 254, and the laser diode 259 enters the output P (ON> state).3 The first of the two input circuits is connected to the output of the inverter 253, and the input of the inverter 253 is connected to the print data 847 (prints at HIGH level, does not print at LOW level).The second is connected to the inverter 253. 252, and the input of the inverter 252 is connected to a shadow signal 348 (shadow on at HIGH level, off at LOW).The third is a laser enable signal 349 (shadow enabled at HIGH level, LOW Therefore, the condition that the output of the NAND gate 246 becomes LOW level is that the laser enable signal S49 is HIGH.
GH, shadow signal 848 is LOW, print data signal S
47 is LOW. Next, 247 is a 3NAND gate, and when all three gate inputs are at the 1-110H level, the output becomes LOW level, turning on the analog switch 255, and turning on the laser diode 259.
becomes the output P(SH) state. The first of the three input gates is connected to the shadow output 84B, the second to the output of the inverter 253 which is the inverted signal of the print data signal S47, and the third to the laser enable signal 849. Therefore, the NAND gate 24
The conditions for the output of 7 to be LOW level are that the laser enable signal 349 is HIGH and the shadow signal 84B is HIGH.
GH, when the print data signal s47 is ON. Next, 248 is a 20R gate, which of the two gate inputs becomes LOW level.
The output becomes [OW level, and the analog switch 25
6 is turned ON, and the laser diode 259 becomes OFF state output P (OFF) state.

245 is a sample and hold IC, which converts the output of the laser diode 259 into the shadow output P(SH
) is used to control

ANAL and OG-INPUT are sampled analog voltage inputs, SAMPLEC is a connection terminal for a hold capacitor CO8, and 5TROBE is a sampling strobe signal terminal, which is connected to a sample strobe signal S46. 237 is an operational amplifier with an FET input, and constitutes a Porchi 27407 circuit. DO3 is a wide Runny diode that regulates the output of the laser diode 259 to be within the maximum rating.

Further, the resistor R40 and the capacitor CO7 constitute an integrating circuit, and the resistor R41 is a discharging resistor for discharging the charge of the capacitor CO7 at a constant rate. 236 is an analog switch whose gate (G) is a buffer 244
The input of the buffer 244 is connected to the input signal 845 . 253 is a transistor for level conversion, and R39 serves as a current limiting resistor when charging the capacitor CO7. R38 is a base current limiting resistor of the transistor 235, 234 is a comparator serving as a comparison means, and the comparator J is composed of resistors R34 and R35.
It has a hysteresis characteristic due to the action of .

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 making R01 an eyelid, it is possible to avoid changing the amplification degree of the operational amplifier 232. R31 is an output load resistance of the photodiode 260 in the semiconductor laser f-344, and a voltage proportional to the output current of the photodiode 260 is obtained. FIG. 19 shows the relationship between the short circuit current IS 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+w, the output of P(SH) is approximately 4mw, and the output of P(O
FF) is set to O. Also, LA-A and LA-8 are 2
It represents the monitoring characteristics of a street laser diode. 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 6111W. Therefore C1 first
The characteristics of both graphs LA-A and 1A-8 in FIG. 9 can be adjusted by the volume VRO1.

238 is a comparator for checking whether the laser and diode 259 are emitting light, and the output voltage of the operational amplifier 232 is applied to the - side input. Further, a voltage divided by resistors R36 and R37 (in this case, it is set to 2.0 cm) is applied to the negative side. Therefore, the laser diode 259 emits light and its output is about 2111W, which changes from LOW level to HIGH level.
The level changes and a laser laser 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. A voltage divided by a main exposure adjustment volume 360 and a resistor R45, which is a first voltage variable means, is input to the input terminal of the voltage follower 239.
By varying 0, the voltage at one terminal of the comparator 234 also changes. Further, the analog switch 241' is turned ON when the laser output P (SH) is set, and the output voltage of the voltage follower 239 is adjusted between the resistor R46 and the shadow exposure adjustment volume 3 which is the second voltage variable means.
The voltage divided by 61 is applied to the comparator 234.
is applied to one side input terminal. The above voltage follower 239, 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. In addition, a monitor photodiode 260
A circuit that compares the voltage detected by the monitor amplifier 324 and amplified by the monitor amplifier 324 with a set voltage by the comparator 234, and integrates the comparison value is called an optical output stabilizing means.

The analog switches 240 and 241 are switched by the main exposure setting signal 6844. That is, when the main exposure setting signal S44 is at a LOW level, the output level of the inverter 242 is -110+-
The analog switch 241 is turned on. Further, when the main exposure setting signal S44 is at the HIGF level, the output of the buffer 243 becomes the l-11G)- level, and the analog switch 240 is turned on. The outputs (S side) of the analog switches 240 and 241 are also input to a voltage follower 261, and the voltage follower 261 is used to correct the threshold level of a horizontal synchronization pulse detection comparator of a beam detection circuit, which will be described later.
The output 850 of is 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℃, TC=50
°C is the IF-PO characteristic when the case temperature is 50 °C. Taking the characteristic of case temperature TC=25° C. as an example, when the current IF flowing through the laser diode 259 is gradually increased from 0, the optical output PO starts to be output from a point of about 50111A. Then, at the point of IF=68inA, the P
(ON> optical output is 6 mw.

Therefore, even when TC=0°C, the optical output PO starts to be output at a point of about 40111A, so by turning on the transistor 258, the laser enable signal S4.9 is At this time, the bias current IFB is always passed to reduce the power loss of the rape modulation transistor 257. Therefore, the laser modulation transistor 25
7 guarantees extremely stable operation even at high temperatures due to the effect of the bias current IFB. Also, the amount of change in current required to modulate the laser is, for example, TC = 25
In the case of 1F25-IFB, the accuracy of the light amount stabilization operation, which will be described later, can be made considerably better than when the transistor 257 directly drives a current of 1F25-IFB. Furthermore, as is clear from the graph, the output of the laser diode itself changes considerably depending on the temperature, so the light quenching stabilization circuit is necessary. In this laser light quantity stabilizing circuit, the light quantity from the laser diode 259 is detected by a monitor photodiode 260, and the short circuit current S of the photodiode 260 is controlled so as to always be constant. 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, so the monitor current! If S 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-mentioned optical output stabilizing circuit will be explained using FIG. 17 and FIG. 20.

When the laser enable signal S49 and the sample signal 345 both reach -110+- level in FIG. 20, the transistor 258 in FIG.
A bias current (approximately 30 mA) flows through the laser diode 259 through the laser diode 259 .

Also, at this time, both the print data signal 847 and the shadow signal 848 are at LOW level, so game 1 to
Among the gates 246, 24.7, and 24.8, all the inputs of the gate 246 are at the HIG level, so the output becomes the LOW level, and the analog switch 254 among the analog switches 254, 255, and 256 is turned on. Also,
When the sample signal $45 becomes )IIG)-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 diodes 2 and /19, and the laser diodes do not emit light, as can be seen from the characteristics shown in FIG. Since the laser diode monitor photodiode 260 does not emit light, the monitor current Is is O.
Since the output of the operational amplifier 232 is OV, the output of the comparator 234 is at a LOW level, and the transistor 235 is turned off.

Since the transistor 235 is OFF, the capacitor CO
7 is connected 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 stabilization circuit will be too fast,
Fluctuations in the laser light output level increase. Moreover, if it is too large, the responsiveness will deteriorate and it will take time for the optical output to stabilize. By applying the chip 11 to the capacitor CO7, the output voltage of the voltage follower 237 also gradually increases. Therefore, as the base voltage of the radar modulation transistor 257 increases, a current flows through the collector. Transistor 257 (D) at this time
The evening light mlc 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 1c from the transistor 257 flows through the laser diode 259. Then the current 1c increases and the laser diode 2
The forward current IF of 59 is approximately 50mA (TC=2
5°C) (then 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 A amplifier 23
The input terminal voltage of 2 is one level, and the output voltage is an amplified version of the input voltage. Since the amplification degree of the operational amplifier 232 is adjusted in advance by Polycomb VROI so that the output voltage of the operational amplifier 232 is approximately 0.5V with respect to the output lll1w of the laser diode 259, the optical output of the laser diode 259 increases, and the optical output of the laser diode 259 increases to approximately 2.
Inw, when the output voltage of the operational amplifier 232 reaches approximately 1V, the output signal of the comparator 238, that is, the laser ready signal S43 changes from LOW to HIG1-4 level. Since the main exposure setting signal 844 is at the 1-OW level, it is input to the one side input terminal of the comparator 234 through the analog switch 241 (low exposure level (optical output P).
(SH)) voltage is applied. This voltage is
The shadow exposure level voltage is set according to the impression characteristics of 01 by the shadow exposure setting volume 361 in the operation section. Now, the voltage corresponding to the average value of 4mW of optical output is 2. It says it's an 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 23
5 is turned on, and JCO7 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 4n+w or less. The optical output of the laser diode 259 becomes When the voltage becomes 4IllW or less, the voltage at the + side input terminal of the comparator 234 also becomes 2.0V 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 4n+w, and the comparator 234 repeats the 0N10FF operation at a constant cycle. Furthermore, this two lmparator 234
Since it has a hysteresis characteristic, comparative judgments are stabilized and reliable judgments can be made. Then, due to the integral effect of the resistors R39 and R40, the capacitor cO
The voltage across 7 approaches the value 01 in FIG. 20 and becomes stable. After the laser ready signal 843 becomes HIGH, the microprocessor 101 outputs a shadow level sample strobe signal 846 through the output port after a predetermined time t6 has elapsed. When the sample strobe signal is output, the sample and hold IC245 samples and holds the voltage VO1 (Fig. 20) of the capacitor CO7 that is input to the ANALOG-INPLJ'r input terminal, and outputs the voltage to the hold capacitor CO8.
Write down the voltage. Therefore, after the sample strobe signal is turned off, the output of the sample hold IC is OUT.
, the /jth control voltage VO1 that causes the shadow level P (St-1) to be output continues to be output.

Next, when the sample and hold operation of the shadow level P(SH) is completed, the microphone processor 101 switches the main exposure setting signal S44 to HIG)-level through the output port. The output voltage of the voltage follower 239 is applied through 240. The output of the voltage follower 239 has the main exposure level (light output P(O
N), ) voltage is being output. This voltage is applied to the photoreceptor 30
It is assumed that the voltage set by the main exposure setting volume 360 in the operation unit according to the sensitivity characteristic of 1 is currently outputting a voltage 3, OV, which corresponds to an average value of optical output of 5 mw. Therefore, the output of the converter 234 is L due to the input terminal on one side being switched to 3.0■.
The signal becomes OW level and the transistor 235 is turned 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. And the optical output of the laser diode 259 is 6+n
When it comes to around w, the output voltage of the operational amplifier 232 ■232
is approximately 3■. When the output voltage of the A amplifier 232 becomes 3■ or higher, the output of the comparator 234 changes to HI G ) - (, turning on the transistor 235, and the capacitor CO7 connects to the resistor R4.
C dimechi 1 through 0? - Digitized. Therefore, the base voltage of the laser modulation transistor 257 also decreases, and the optical output of the laser diode 259 becomes 6IllW or less. When the optical output of the laser diode 259 becomes 6 mW or less, the + side input terminal voltage of the comparator 234 also becomes 3.0 V.
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 5 mW or more.

In this way, when the optical output of the laser diode 259 is around 6 mW, the amparator 234 repeats the 0N10FF operation at a constant cycle, and then the resistors R39 and R40
Due to the integral effect of
It approaches 0 figure VO2 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, to input print data into the photoreceptor 301. The sample timer is triggered one after another at a constant period T every time a laser beam detection signal, which will be described later, arrives, and outputs a numbering signal S4'5 only in a portion other than the print data writing operation, that is, in the section shown in FIG. 20a. Since the sample signal 345 is at the LOW level in the section of the print data 847 and the side 17 data 848, the analog switch 236 is turned off. Therefore, print data D
In the printing area where the laser diode 259 is modulated by the shadow signal 347 and the shadow signal 348, the level of the optical output of the laser diode 259 is P(ON), as described above.
There are three levels: P (SH) and P (OFF).

That is, first, the print data signal S47 is OFF, that is, the OW level, and the shadow signal is OFF, that is, LOW.
N at W level (white output for printing)
AND game l-246 is established and analog switch 254
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)=6n+w. Second, when the print data signal 847 is OFF and the shadow signal is ON (the printing output is a halftone), the NAND gate 247 is established, only the analog switch 255 is turned ON, and the modulation transistor 25
The output type 11fVO1 of the simple hold IC 245 is applied to the base of the laser diode 259.
The optical output of is P(SH)=4n+w. The third case is when the print data signal 847 is ON and the shadow signal is OFF (the print output is black), and the OR gate 24
8 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 269 becomes P(OFF)-0 and does not emit light. 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 resets the shadow exposure level P (SH). Therefore, the voltage at one side input terminal of the comparator 234 becomes 2.OV, which is the set voltage of the shadow exposure level. Therefore, the transistor 235 is turned on, the capacitor CO7 is discharged, and V'CO7 becomes smaller. Here, we will explain the operation of stabilizing the optical output of a laser diode.
During the second printing operation, the laser diode 34
Assume that the case temperature of No. 4 has increased by ΔT. 18th
As is clear from the characteristic diagram in the figure, the case temperature increases 1
-, 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. Therefore, in order to obtain the same optical output, IF must be increased by the amount of current ΔIF corresponding to the shift of the characteristic curve to the right. Therefore, the voltage VCO7 of the capacitor CO7 is set to VO3 which is higher than the first setting voltage VO1 by the voltage △v1 corresponding to the △IF, and the optical output of the laser diode 259 is the same as the first setting P(SH)= It is set to 4n+w. Then, like the first time, the shadow exposure level P (ON) is set in the sample hold TC 245 by the sample strobe signal S46. At this time as well, the operation corresponds to the rise in temperature of the case of the laser diode 344, and the voltage of the printer υCO7 is set to VO4, which is higher by the correction voltage △V2 due to the increase in temperature, and after setting, the same printing is performed on the second cylinder. . In this way, the shadow exposure level P(SH) and the main exposure level P(O
N) is maintained at a constant level very accurately by the function of a stabilizing circuit, making it possible to perform high quality printing. Incidentally, as described above, the main exposure level P (ON) performs the light (4) stabilizing operation so that the light output is always kept constant except during the writing of print data. Furthermore, for the shadow exposure level, a sample hold operation is performed before each print starts, and unlike the main exposure level, the photofurnace 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 print quality. If the set voltage input to the comparator 234 is to be varied depending on the sensitivity characteristics of the photoreceptor 201, the main exposure setting volume 360 is adjusted. This main exposure setting volume 360 is adapted to vary the input voltage of the voltage follower 239. Therefore, by varying the main exposure setting volume 360, the light output setting voltage when P (ON>) can be adjusted. On the other hand, the light output setting voltage when P (SH) is determined by adjusting the output voltage of the voltage follower 239 by adjusting the output voltage of the voltage follower 239. The pressure is divided by the shadow exposure setting volume 361.

Therefore, by adjusting the main exposure setting volume 360, the light output setting voltage at P (ON) and P (SR) times changes proportionally, thereby maintaining a constant relationship between recording density and applied voltage. can be kept. Therefore, the adjustment becomes simple without requiring the complicated operation of varying and adjusting the set voltages for both P(ON> and P(SH) times as in the prior art).

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.
This serves as a reference pulse when writing print data to the printer, and its 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 test koji 346 is connected to one side input terminal of a high-speed filter 262, which is a comparison means, through a load resistor R52 and a resistor R55. Also, 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.
A threshold-L hold variable voltage S50 is applied through a 0° resistor R57. This threshold variable voltage 850 is the output of the analog switch 240 or the analog switch 241 (output of the optical output setting means) (
(See Figure 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.
, b are input. Now, suppose that the voltage at the + side input terminal of the comparator 262 is always a low voltage VO6 because the threshold variable voltage S50 is not applied, the output waveform of the comparator 262 is a waveform a.
In the case of , the output waveform is as shown by the dotted line, and in the case of waveform , the output waveform is as shown by the solid line. Here, the waveform a represents a waveform when the sensitivity of the photoreceptor 301 is low and the laser output during the main exposure is 6 iW or more, whereas the waveform a represents a waveform when the sensitivity of the photoreceptor 301 is high and the laser output is 5 mW or less. As can be seen from this output waveform, when the voltage on one side 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 variable threshold voltage 850 to correct the voltage of VO5 when the light intensity of the laser beam is large and the voltage of VO6 when the intensity of laser beam is small, the output waveform is kept almost constant as shown in Figure 22. It is possible to maintain the

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 2.5 x 2.5111 m and a response time of 4 n5e.
It is of c.

The lower laser beam 413 is scanned at a constant speed in the direction of the arrow in FIG. An output current flows in accordance with the optical output.At this time, the input 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 use when the light receiving element 410 itself is used for detecting light that is originally stationary or for detecting very slow fast-moving light even when it is being scanned. There are quite a lot of elements with poor performance, and when the laser beam passes through the end face of such elements, 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 surface is prevented. The mask 41
2 is a light receiving element 41 as shown in FIG. 23 (A>, (B)).
The laser beam 41 has a structure in which a square window is opened in the end face portion of the laser beam 411 and the portion that does not include the electrode wire 411 lead-out portion.
3, the light is made to hit the light receiving element 410 only when it passes through the four corner windows. With such a structure, the accuracy, particularly the parallelism, of the window portion of the mask is increased, so that 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 writing control circuit 119 are as follows:
The parallel print data S57 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. Further, a timing signal for controlling the 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, reference numeral 186 denotes an input/output port for transmitting and receiving signals necessary for control within the laser modulation circuit 120 and the print data writing control circuit 119, and 187.
188 is a counter/timer that controls the writing position of print data, test pattern generation, and optical output sampling. 189 is a crystal oscillator that serves as a reference clock for image clock pulses and has an oscillation frequency. Approximately 3
It is 2M to 1z. 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, and 211 is a circuit that generates test pattern data and interface [
A multiplexer 210 selects between the print data from the multiplexer 211 and the print data from the multiplexer 211.
A shift register converts bit parallel data into serial data, 213 and 214 are line memories that temporarily store 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 the test pattern generation circuit. This is a decoder for creating signals to control the 226,227.22
Reference numeral 8 denotes a control flop for synchronizing the timing of sending print data and shadow data.

Here, the details of the counters 187 and 188 will be explained. 275 is a counter that determines the timing for half-correction of the laser beam for each line (horizontal scanning line), and counts based on the reference clock signal S53, and generates a sample signal 375 used for light amount correction and line start. . 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 S84. A counter 277 determines the recording end position in the horizontal direction, and counts based on the video 8-dot unit signal 8.83, and outputs a data writing end position (write margin) signal S85. 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 374 output from the input/output port 186 and the Q output of the flip 70 knob 204. is performed and a page top count output S76 is generated.

Numeral 279 is a vertical recording end positioning counter which counts based on the output of gate 198 and outputs page end count signal 877 as described above. 280
is a vertical test pattern control counter which performs counting based on the Q output of the knob 70 and knob 240, and outputs a test pattern control signal S79.

Figure 26 shows the interface circuit 12 in Figure m13.
2 is a detailed circuit diagram of No. 2. In FIG. 26, 263 is an input/output port that 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 is an 8-bit latch for both command and print data.

265 is a transceiver/receiver for the interface data bus 859. Reference numeral 266 indicates a decoder for the data selection signal S60 that specifies data on the data bus 359, and reference numeral 269 indicates a control circuit for the BUSY 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, S59 is a bidirectional 8-bit 1~data bus, and S60 is a data selection signal on data bus S59.
Data on the data bus S590 is selected by a combination of two signals DC0M and ID5TΔ. S61 is IPR
A signal indicating that the print control unit 100 is in a ready state at DY.

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

S64 is If (SYN, which is a request signal for sending 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; 866 is IBSY, which is a request signal for sending one line of print data; 866 is IBSY, which is a request signal for sending one line of print data; This is a signal that authorizes sending and reading status data on the data control unit 2 side.

Commands and print data are sent to transceiver/receiver 26
Status identification (g 8 S
It is output when 68 is OFF. Output line 872
The above data is latched into data latch 264 by strobe signal 830. In the case of command data, the data is wrapped in the input/output port 263, and after the command is identified, 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 line S59. 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 S71 of the input/output port 263. The set status data S71 is transmitted to the transceiver/receiver 265.
is input. The input data is output onto the data bus S59 when the status identification signal 868 is ON.

Details of the commands and statuses used in the print control unit 100 are shown in Figures 127 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 fuser 331, and PSO,F is a command to cancel the power save state, and when not recording, the power sage command PSON reduces the power consumption of the fuser 331 to save power. During recording, the power can be increased to the normal value using the power rape release command PSOF to fix the treble. C3TU is a cassette upper stage paper feed designation command, C3TL is also a lower stage designation command, VSYNC is a command to instruct the start of sending print data from the data control unit 2, vr: to 1/9 is a manual feed mode designation command, TBM1 to 4 is a top/bottom margin specification command that specifies the printing start position on paper, S
OF indicates a command for forcibly turning off shadow exposure.

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) indicate the size code of the installed cassette. Test/Maintenance indicates the status of the test/maintenance state. Data resend request indicates when reprinting is necessary 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 the power save mode by the power save command (PsON>). 4 indicates that an operator call factor has occurred.Serviceman call indicates that a serviceman call factor of status 5 has occurred.1°Tray full indicates that there are more than the specified number of sheets in the paper output tray. Toner pack replacement does not indicate that the toner bag is full. Paper jam indicates that paper has jammed inside the machine. No donor indicates that there is no toner in the toner hopper. Cover open indicates that the front door is not open. Timing error indicates that there was a problem in transferring print data. Fuser failure indicates that the fuser is disconnected, Indicates that there is an abnormality in the fuser, such as temperature FtJSE running out.J0 Laser failure indicates that the laser diode does not reach the specified output or the beam detector cannot detect the beam.Scan motor failure indicates that the scan motor is starting up. This indicates that the specified number of rotations has not been reached even after a certain period of time has elapsed, or that the number of rotations has deviated from the specified number of rotations for some reason after reaching the specified number of rotations.

Heat roller replacement indicates that the fuser roller counter shown in FIG. 15 has reached a specified value and that the fixing ports need 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 is a diagram showing the positional relationship between the scanning range of the photoreceptor 301-F in FIG. 3 and the beam detection position and data writing position within the scanning range. 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 by the next surface of the polygon mirror 313 at a time O'c from the beam scanning starting point 416. Begin scanning the beam. 4
18 indicates the beam detection starting point of the beam detector 346;
Reference numeral 428 indicates the left end surface of the photosensitive drum, and 429 indicates the right end surface. 419 is the left end surface of paper size A3,
Similarly, 420 represents the right end surface. 421 is paper size A
3 represents the left end surface of the paper, and 420 similarly represents the right end surface. 42
1 is the starting point for data writing on the same A3 size paper, 422
also indicates the data writing end point J0 423 is the left end surface of the paper size 86, 424 is the right end surface, 425 is the data writing start point of the same size, 426
Similarly, each represents the end point of data writing. Also 42
7 represents the center point of the paper.

dAL + beer, water A1Ω to h8') 4-1) Push: λ Distance to the song start point, d5 is the same < distance to the A6 size writing start point, -66 is the same < A6 size writing The distance to the end point 426, d7 represents the distance to the end point of A3 size writing, respectively.Le-0d8 represents the beam detection point 4
18 represents the distance to the right end surface 420 of the paper in A3 size. Further, d3 represents the range of one scanning of the beam. d14.
d9. dlo indicates the effective printing range in A3 and 80, 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 41B varies depending on the paper size. It is necessary to write data after a lapse of time corresponding to the distance from the beam detector 346 detecting the beam to each writing start point. Instead of performing such control, this printer does not employ a paper edge feeding 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+u, but it is possible to set them to O. Further, conventional printers that perform edge feed conveyance usually require a margin of about 8-10++ un, which has the disadvantage that a considerable 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 Δ3 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 start point of data insertion in the vertical direction of the paper, 431 represents the trailing edge of the A3 size paper, and 433 represents the aforementioned end point of the A3 size data. 434 represents the trailing edge of A6 size paper, and 435 represents the end point of A6 size data insertion.

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

Ready signal IPRDYO (861) of print control unit 100
becomes ready for printing.

At the same time, the print start signal IPREQO (862) becomes active. Next, the laser enable signal LDON1
(S49) rises to 1'. This signal S49 causes the first
The transistor 258 shown in FIG. 7 is turned on. At this time, the data flip-flops 226 to 228 in FIG. 25 are not set, so the print data signal 847 and the shadow signal 348 are both 0'. Since the laser enable 849 is 1', the print data is Oo, and the shadow signal 848 is 0', the gate 246 in FIG. 17 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 the laser ready MLRDYI (843) is generated. Next, the horizontal circumference w4 signal H8YO (854) d, l1il)llL
The sample signal SMPTO(S
75) occurs. This signal 375 is the distance d between 416 and 417 in FIG. 29 that defines the paper size.
3 (distance of one line). 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, the sample signal 345 is generated from the gate 194, and this sample signal S45 turns on the analog switch 236 via the gate 244 in FIG. is applied to the laser diode 259, thus performing light 1 correction for each line. PTCTO
(S76) is an output signal of a counter (page top counter) that determines the leading edge of the paper, and PFCTO (S77) is an output signal of a counter (page end counter) that determines the end position of the paper. When the timing to write the image comes, the status of the VSYNC request is sent to the external device. Due to this, a VSYNC command is issued, and when a telegraph is received, a PTOP (873) is issued and the number of H8YNC lines begins to be counted from that point. In the same way, specify the number of strokes to be played from that position (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, a P-T OP signal is output before the leading edge of the paper when VSYNC is received. For example, 5In
If Ill margin is necessary, count the number of lines including it.

If the top value is 1.0 mm, data corresponding to that value will be set in the timer. The position of the bottom can be determined in the same way. When f-night is set on the timer, the gate is checked from there and a C count is performed, and when the count is completed, it rises. Gate 201 in FIG. 25 determines where to write in this way. L.S.
TO (878) is flip-flop 2 for synchronization
04 Q output, set by H3YNC, 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 the reset is forced to hIG. The reset generates the Q output of the flip-flop 204,
Clock generation circuit 190 operates and counts clocks from oscillator 189. This clock generation circuit 190 is the oscillator 1
The 89 clock is divided by 4, and a bit-by-bit signal is used as a line start signal, which is output only while ST is set. This output becomes two types of signals 882 and 887 with different phases. As a result, synchronization for -lines is achieved. VDATI is the print data signal (84
7), the signal is output as serial data by the operation of the P/S conversion shift register 210. That is, the P/S conversion shift register 210 is operated by the signal 382 from the clock generation circuit 190, but when the load signal is not applied, the output S86 is 0' (no laser writing), and the load signal is not applied. Data D when signal S88 is input
5 to D12 are serially converted and output.

At this time, the gates 207 to 209 are loaded into the C8 bit in one cycle. Here, the generation timing of the load signal will be explained.

When there is a place where you actually want to write, you will have to write the data when the paper size changes, but you can control this.
The left margin counter 27 in FIG.
6 (data is 69.dlo in Fig. 29), and it merge counter 277 (F- data is dll, dlo in Fig. 29).
12>, so there is. In this case, the setting defines the distance between the left and right sides with respect to the center of the paper. H
When the LST signal (S78) is output in synchronization with 3YNCtgQ, the Noritsu flop 196 is set, which causes the gate 198 to flicker and the counter 276 to start counting. In this case, the video clock is not counted in 1 bit 1d, but once in 8 bits. The count output that comes out every 8 bits is the left margin N 1m1 right margin NRI
If you set it according to ll, ST signal (878)
Counting is performed in synchronization with Then, it starts up after setting and outputting the count number. Therefore, the gate 2'01 determines the vertical direction, and the gate 199 determines the horizontal direction, so that writing is performed in the bind when the outputs of both gates become (1, 1). At this timing, the load signal is output, and the data 386 from the shift register 210 is serially converted and sent.

Line memory out signal LMOT (S80) is the output of OR gate 222. This is for controlling which data from the line memories 213 and 214 is to be sent. That is, this sending timing is flip 70 knob 2.
Controlled by 03. That is, the output state of this flip-flop 203 changes every time a clock pulse is applied, and the gates 220 and 221 are opened alternately, so that the output D OU "r of the line memory 213 or 214 is crossed. The writing timing to the line memories 213 and 214 is also determined by the gate 217.
．． 218 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 employing the Siredo method, which will be described later.

Next, LDAONl (S81) will be explained with reference to FIG. 43.

In this type of recording device, when the laser is not emitted over the entire axial direction of the photoconductor 301, for example, when the laser is not emitted over the entire axial direction of the photoconductor 301, for example, a small size paper (such as B5 YA △4 such as paper 45B shown in FIG. 43) is emitted. In many cases, printing is performed only on the paper, and as a result, toner or the like does 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 an area where I~Luna does not adhere for a long period of time is provided in this way, when the blade scrapes off the adhered toner after recording, the contact resistance of the blade at the unadhered area becomes large, causing scratches on the surface of the photoreceptor. There's a problem. So with this device. As shown in the time chart of FIG. 31, the line data on signal LDAON 1 (S, 8
1) is generated and the print data signal V is generated within this generation period.
DAT1 (847) is forcibly applied, and as a result of this operation, images 460 and 463 are printed on the entire surface of the photoconductor in the axial direction as shown in FIG. 43 after printing for one sheet of paper is completed. The above drawbacks are removed in this way. In this case, the line data writing timing is generated when a predetermined time tx has elapsed from the falling edge of data LDATn-1, which is one stage before the final stage data LDATn in the data of the line memory out signal LMOT1 (880). I try to do that. Note that such lines are not necessarily written periodically after each sheet of paper has been printed, but can be set to be written every lot (for example, every 10 sheets or every 100 sheets). You may.

Next, refer to Figures 33 to 36 for details on the method used to make characters easier to see by adding a shadow to the printed characters (also called the shadow method). Describe.

Determination as to whether or not to generate the shadow signal S48 is made by various gates 220 to 225 which alternately input the data of the line memories 213 and 214, and three flip 70 tabs 2.
26 to 228 and the gate 231 on the output side thereof. Among them, the flip 70 knob 227 is horizontal (
The flip-flop 228 contributes to determining a shadow based on a change in level in the vertical direction (line direction), and to determining a shadow based on a change in level in the vertical direction (vertical direction). That is, the serial data to be written is read from the line memory 213 and is stored in 7 lip 70.
If the knob 226 is set, the data in the previous line direction is contained in the 7 lip 70 knob 227, so for example, when the current data is 0' and the previous data is 1', the shadow signal 348 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", 7 lip-flop is set and a shadow signal is generated.
A shadow signal is also generated when both flip-flops 227, 228 are set. This state is shown in FIG. 32 by shadow out signal 5OLJT1 (886), print data signal VDAT1 (S47), and shadow signal 5DAI-1 (
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 characters ``1 謹'' are printed, a shadow is added to FIG. 32, making it very easy to see.

Figure 36 is vertical 1! A characteristic diagram P showing the relationship between exposure position and exposure energy is shown in the upper right area of the figure, intersecting S1 and horizontal 182.
AT1. Characteristic diagram Q shows the relationship between the surface potential of the photoreceptor and exposure energy in the upper left area of the figure, and characteristic diagrams R1 and R2 show the relationship between the exposure position and surface potential in the lower left area of the figure.
are shown respectively. In this figure, among the characters in FIGS. 33 and 34, "8" in the Y direction and "1" in the Y direction.
4 to 21-1 were extracted. As shown in the figure, the characteristics PAT1 and R1 of the pattern shown in FIG.
Features of the pattern shown in Figure 4! t: P A T 2 and R2 are different. In particular, regarding the development characteristics, at a certain development level 1-, the one shown in Figure 3 is R1.
It can be seen that the width D2 of R2 in FIG. 34 is larger than the width D1 of R2 in FIG. FIG. 35 is a characteristic diagram showing the relationship between the exposure position and the exposure energy, and the energy of P(ON> during laser irradiation is, for example, 6 mw, and the energy of P(S H) when creating a shadow portion 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. The third intensity located at 〈
Recording is performed with a beam of 8-ftone),
Determination of this specific relationship is possible when, for example, beam scanning is performed sequentially for each horizontal line. determining that there is a change in the recorded data (to data that does not contribute to character formation), scanning the unintentionally recorded data portion immediately after the change with a beam of a third intensity; and (b) scanning the current line in the horizontal line. The data is compared with the data of the previous line in the vertical direction corresponding to that position, and as in (a) above, when significant recorded data changes to unintentionally recorded data, the unintentionally recorded part immediately after the change is scanning with a beam of 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. If it is something other than image information (for example, image information), "Shadow" is not activated and is automatically performed. The command in this case is shown in Figure 27! jl'5ONF Shadow 0N1
It is 0FFJ. Or on the panel part
A 10FF and I switch may be provided so that the operator can arbitrarily select.

If the above-described shadow method is used, if the recorded information is character information, the "shadow" can be seen, so that the printing quality can be improved. In particular, when recording with a high-density beam, the line "
This prevents "fading" and as a result, the printing temperature of one dot line becomes higher, so the printing quality can be improved even for a high-dot Kanji font such as a 40x40 dot configuration. Further, since the permissible range of vertical deflection of the beam on the photoreceptor due to one-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.
35, the voltage control circuit 445 applies a frequency output to the primary side, and a back pressure transformer 446 that generates a high voltage output from the secondary side, and the output of the 4-voltage transformer 446. a high-voltage rectifier circuit 447 that rectifies the current and applies a rectified output to the charging charger 304; a current/voltage conversion circuit 450 that inputs the current flowing to the charging charger 304 and converts the current into a voltage;
It is composed of an operational amplifier 449 which takes the output of this current/1 degree conversion circuit 450 as one input, and takes the output of the control reference voltage generation circuit 448 as its input. The control reference voltage generation circuit 448 generates an analog control signal S36.
and J: are controlled to output different control reference voltages. According to such a configuration, the control group Q'
The output frequency of the voltage control circuit 445 is determined based on the output from the m Jf- generation circuit 448, and a high voltage output is generated based on this, and the current of the charging charger at this time is applied to the current/voltage conversion circuit 450. However, this output voltage and the reference voltage are compared by the operational amplifier 449, 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 figure, the horizontal axis represents temperature, and the vertical axis represents surface potential change △vO
It shows the type of drum 451゜452, /1
Each 53 has different characteristics. Moreover, FIG. 39 shows each drum 451, 452.
453 is a characteristic diagram showing the relationship between drum inflow current ID and surface potential vO, which is a proportional straight line. Therefore, in order to keep the surface potential constant, the drum inflow current ID
It would be a good idea to change the . For example, in order to maintain a surface potential of 800V for the drum with characteristic 451 in FIG. The inflow current change amount ΔID' corresponding to the potential ΔVO=O.
. Here, since the inflow current ID and the output current have a corresponding relationship as shown in FIG. 40, the charging high voltage power supply circuit 160
The above-mentioned inflow current [D] can be adjusted by changing the analog signal (input voltage B2) S36 to the control reference voltage generation circuit 44 within the range of 2V, 4V, and 6V.

FIG. 41 does not show the relationship between the analog input current (D/Δ in FIG. 15) and the output voltage of the inverter 165 and the temperature.
(→No Mister in FIG. 14) e is detected and the analog control input signal 336 is applied in response to the temperature change.

The charging correction is performed based on the above-mentioned details, 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/[] converter 271 converts it into a digital signal, and when the data conversion is completed, the temperature data DTn and the temperature 2
A value DΔT is read by subtracting the drum temperature data DT25 at 5°C. Next, the reference data DV at a temperature of 25℃
25, calculates DV 25 + DΔ■, and outputs the calculation result DVn to the D/A converter 165. And the address r 60 shown in FIG. 45(B)
The drum characteristic No. is identified by referring to the RAM 107 for the drum characteristic data of 0'OJ, and further the feedback error data DΔ■ is read. Next, the reference data DV at a temperature of 25℃
25 is read, DV25+DΔV is calculated, and the calculation result DVn is output to the D/A converter 165. Then, Vn is applied to the analog input of the charging high-voltage power supply 1160 (336), and the control input signal S35 of the charging high-voltage power supply 160 is turned on to perform correction. -F 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 flowchart ① in FIG. 60, when it is determined whether or not to replace the drum,
If the drum is to be replaced, the drum characteristic No. is set and the DEST key is turned ON, after which the drum characteristic No. 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 charge correction is performed as shown below, the charged potential of the photoreceptor remains constant even if the temperature of the photoreceptor changes due to changes in the external environment or the temperature within the gas. Decrease in charging potential, decrease in printing wetness or charging potential 1
This prevents problems such as fogging caused by printing, and provides clear printing at all times. In addition, in this embodiment, by inputting (external setting) information that categorizes the temperature characteristics of the photoreceptor, corrections are made according to errors, so corrections for charging characteristics can be made with high accuracy. be able to. Therefore, variations in the temperature characteristics of the photoreceptor itself can be alleviated, and there is an advantage that 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 overall operation of the present mounting 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.

Paper ejection switch 336 is OFF, manual stop switch 328 is OFF, path sensor 123 is OFF,
It is checked whether the temperature no-use 130 is disconnected and whether the paper output tray 384 is not full (FULL), and whether the mode is test print mode, maintenance mode, or replacement mode is checked. [When the MC relay 131 is turned on, the fuser heater lamp 333 is turned on, the scan motor 312 is turned on, and timer A (T IMA) is started. Timer AT
When the IMA counts a predetermined time t1, mechanical parts such as the drum motor and developer motor are turned on, and then the TIMA
When counts the predetermined time t2, the laser 344 turns on.
become. When time t25 is counted by 'T'1MA, it is determined whether the laser is ready or not, and if yes (Y), the next 5TIMA=t26 is timed and transfer charge!
! , the laser, the developer motor, and the developing sleeve bias are each turned off, and the drum motor, heat roller motor, static elimination lamp, and pre-transfer static elimination lamp are turned off after roughly TIMA-(27).Next, the TTMA
= Scan motor ready at timing t29, H8
YNC ready is judged and if yes (Y) then TI
MA becomes a stop (Fig. 47).

Next, it is determined whether "Status 4 is 1~Rayfull,""Toner pack replacement" is determined, and whether or not there is "Toner out" is determined. After paper is removed, the "tray full" flag is set to 0', the output tray counter is reset, and if it is "toner pack replacement", the reset is performed when the state returns to its original state. A relette will be held upon return. After passing through the above-L flow, it is determined whether or not it is [Power Saving] in "Status 3", and if No (N>, then "Out of Paper" in Status 41) is determined.
is determined, and if YES (Y), it is determined whether cassette paper out detection is ON or not, and if NO (N>, 1
The paper out J flag is set to O', and if the "fixer is ready", the "status waiting" flag is set to O'. Next, the IP
RDYON and IPREQON are determined, and it is determined whether the power is being saved or not, and whether there is no pairing, and if there is no problem, ITMA starts. TIMA-[01
The registration motor 149 is reversed, and T IMA=t 0
2, the registration motor stops. At this stage, the leading edge of the paper is being held between the paper feed rollers.

Next, it is determined whether "one manual feed" or not, and if no (,N), it is determined whether rlPRNT, ONJ or not, and yes (,N).
Y), it becomes rlPREQ 0FFJ. Next, it is determined whether or not timer E (TIMF) is in operation, and if it is in operation, it is determined that FTIME=t3O, and YES (Y
), it becomes a TIME stop and transfer shaja 30
5. Peeling charger 306. Developer motor 1
41. Each of the fixing device motors 143 is turned on. rT
If IME=t30'J is not satisfied, TIME is stopped and the process moves to the next flow (see FIG. 48).

Next, TIMA starts and plaid solenoid 158
is turned ON, and the developer motor 141. Static elimination lamp 302. Pre-transfer snow removal lamp 303. Each of the drum motors 147 is turned on. r
Transfer charge r305. with TIMA-t21. The fixing device motor 143 is turned on.

IT IMA=t 3J and the break charger 306 is O
Then, when l'TIMA=t4J, [IMA
Start again from O'. 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 forward to feed paper in the -L stage, and if it is the lower cassette, it waits until rTIM'A=t5J. From paper feed motor 15
1 is reversed to feed the lower paper. Then rTIMA=t5
When J, turn on t/-'J"-344, r-r
Turn on the charger 304 when IMA=t 6J
let

Check whether it is laser ready with r'r1MA=t7J, 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 Figure 49).

Next, the paper feed motor 151 is stopped at 100 IMA=31J,
rVsYNc command received” and select YES (Y).
If so, it is determined whether or not rTIMB<t32J, and if yes (Y), TIMB is stopped, the "page top" and "page end counter" counts are started, and image writing processing is performed. Timer〇,D (TIMC,D
), start TIMA at rTIM△=t 34J
Stop, the paper feed motor 151 is stopped. Next rTIM
At c/D=t35.1, the registration motor 149 rotates forward, the torque r sinter 354 is turned on, and rTIMc/D=t3.
6" to determine whether the tonneau degree is high or low. If the density is low, the toner supply motor 159 is turned on.

"Next page end interrupt" is determined, and yes (Y)
If t', image writing ends 1j'ENl) A pulse is output. After that, set each counter to +1 and do a trayful.
, 1 drum replacement", "Developer replacement".

If "heat roller replacement" is selected, each status will be displayed. In addition, the determination result of "receive rVSYNC command" is as follows.
If no (N), the charger 304 is turned off when rTIMB=t46, and r'l1MB=t47. Laser 344. Hack charger 304 OFF, rTIMB
= t47J and laser 344. Hatakuchaja 306
．． Turn off each developer motor 141, rTIMB=
Transfer jersey y305 with t48J. Fuser motor 14
3 to 0 [(:, rTIMB, -t49J turns off the driver l\motor 147, static elimination lamp 302, pre-transfer static elimination lamp 303, respectively, rTIMB=t50'' turns off the blade solenoid 158.

Also, in the flow of rTIMB<t 32J, -(N)
If so, then determine [14MB<t 33J, and no(
N), TIMB stop and T1MA start. After that, turn on the plaid solenoid 158 and
'T IMA=t At the stage of 1.1, the developer eta 141
．． Drum sweater 147. Static elimination lamp 302. Each of the pre-transfer start/start lamps 303 is turned on. And “Ding IMA
=t2J, transfer charger 305. The fixing device motor 143 is turned on, and the peeling charger 30G is turned on when IT IMΔ-t3J. Then rTIMA=t
4J or not, timer A is stopped by -H and restarted. And the developer motor 14
1. Transcription 1! -ja305. Hakuli charger 306
．． Each of the fixing device motors 143 is turned on. rTIM
Laser 344 ON at A=t5j, rTIM=t6J
Charge chiller 304 is ON, rT]MA=t At 7J, it is determined whether the laser is ready or not, and if yes (Y), TIMA is stopped (see FIG. 50).

Next, it is determined whether or not the toner full detection switch 126JON/Jl is ON, and if it is ON, a display is displayed. ], and if it is not manual feeding, then it is determined that there is no paper in the specified cassette, and if there is no paper, a message to that effect is displayed, and 5TPF <
(stop flag) to 1'. Next, timer F(T'
Start IME>. If the stop flag is “1”, set 5TPF to 0’ and print ready IPRDY.
Turn off. If it is not 5TPF・-1, it is determined whether it is 1 manual feed 1 or not, and if it is manual feed 1j, TI
MF stop, manicual stop switch 3280
It is determined whether or not F F , thousand insert "O', TIMB stop, cassette paper out detection switch is ON, and then the print request lPR [Q becomes ON, and the flow shifts to ■ in FIG. 48 ( (Figure 51 above).

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

On the 8th, it is determined whether timers A, B, C, D, and E are each in operation, and if each is in operation, a count is counted up. Read all input information in the port input reading part. and rTIMc/D=t38. I stops the timer, determines whether rTIIVjE = t39J, and thereafter continues the operation of timer E (TIME).
r registration motor 149] is stopped. Then FT
After IME-t 4J, determine whether FT'1MA is in operation (this is to determine whether the next sheet of paper will be printed), If TIMA is in operation, TIMA is in operation. M Stop the E. That[TIME7
t41JF band'flfv-di t304OFF.

rT IME=t 42J and laser 344. Hatari Charger 306. Turn off each developer motor 141
Tozuru. FTIME=t43. Transfer charger 30 with I
5. Turn off the fuser -9143 and rTIME respectively.
=t 44J, drum motor 147, static elimination lamp 302
．． Pre-transfer static elimination) Turn off each of the pumps 3 and 3 (see Figure 5.2 for the above).

rTIME=t 45J and plaid solenoid 158O
FF; TIME stop, [Fuser temperature normal, I or not determination, [Fuser temperature fuse stage is 1, "Sukishin motor 312 ready"], [Door switch 1290F'F
A determination is made as to whether this is the case, and various processes are performed depending on each state.

Next, the contents of the command interruption in each flow will be explained with reference to FIG. 54. When processing of the command interrupt is started, it is determined whether or not there is a "paridity error", and if it is an error, the [Status DATA81J flag becomes 1' and becomes [Illegal Command Error]. If it is not “Parity 1 error” then “Status Request” is SR1~
It is determined whether the number is within the range of 6, and if it is within the range, a 7j output is generated corresponding to one of them. If none of the [Status Requests] apply, it is determined whether it is [Top/Bottom Margin], and if so, [Top/Bottom Margin] is selected.
Bottom margin 1 is specified [1 in status set J
', and any one of rDATA21 to 111 is specified. If it is not [Top/Bottom Margin], it is determined whether or not it is "manual feed designation", and if yes (Y), manual feed display and paper size display are performed next, and the paper size register is set. Then manually feed status set (status 1 and rDAl-A41j flag becomes "1", then status 4 and paper out flag becomes 0')
Shift to the flow. If it is not "manual feed specification", it is determined whether the cassette specification is J or not, and if it is "cassette specification", the upper/lower display paper size is displayed, the paper size register is set, the manual feed status is reset, and the status becomes 1. , DTA41 flag "0',
It is determined whether there is no paper or not, and if there is no paper, the flag becomes 1'. [If the cassette designation is not J, it is determined whether the [select lamp is lit] or not, and it is determined whether the online select lamp (specified by an external device, for example, the host side) is lit, and if yes (Y). If so, it becomes a pair of select lamps, and if the select lamp is not lit, it is determined whether or not the select lamp is off.If yes, the select lamp goes out, 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 J, "power save" is included in FIG.

Control the fuser to the power heap temperature, [set the status 3 power save flag to 1J, turn on the scan motor 312 when power save is canceled, control the fuser to the normal temperature, [7 lag O during status 3 power save]
], and if it is [Image data transfer start], then Fig. 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 5mm,
If the answer is 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, and the margin adjustment table data D3 is added to and subtracted from the values of Dl and (DI+D2>), 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 5Il1
m or not, and if no (N), the top/bottom margin change table data 02 is read, the bottom margin table data D5 is subtracted from the margin change table data D2, and the top margin The contents of the adjustment switch 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 or not the upper stage (reference) is selected, and if it is not the upper stage, it is the lower stage, the contents of the cassette upper/lower stage adjustment switch (Fig. 14, 44) are read, and the cassette upper/lower stage corresponding to the switch is read. Read the stage adjustment table data o8. Add or subtract the above D8 to the value of the above D7, and the calculation result D9 or the above D7
is set in the write margin counter 277. If manual feed is specified, read the contents of the cassette/manual feed adjustment switch (440 in Figure 14), read the cassette/manual feed adjustment table data []1o corresponding to the switch, and then adjust to the value of D7 above. The table data D10 is added and subtracted, and the calculation result 1) 11 is set in the write margin counter 277.

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 the upper row (reference) is wrong 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 410 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 012, 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.

Details of the above-described cassette paper printing during the flow are shown in the time chart of FIG. 57.

When the print start signal I PRNTφ (S6'5) is output, the print start permission signal I P'RE Qφ (862) rises. Thereafter, the developer motor 141 and the like are turned on, and the feed/paper motor 151 operates between times t4 and t8 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 t7 (the diagonally shaded WJr from time 7 to tll
IR is the data writing period). At time t9, the registration motor 149 rotates, and the old data on the photoreceptor is transferred to the paper. Data writing is performed using TPREQφ(S 62
) falls until time t11, and after time t11 has elapsed, the registration motor 149 continues to rotate until time t12 and 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, but the registration motor 149 is rotated in reverse to drive the paper feed roller, and is used for paper conveyance, and the registration roller is driven by forward rotation. ing. M1=, both [
Manual feed command], then print start command IPRE
Qφ (S62) is made to rise. Figure 58 shows “
This shows a case where paper is set in the manual feed guide before manual feed command 1 is generated, and when the manual feed switch 326 is turned on due to paper setting, time t0
After 1, the registration motor 149 rotates slightly in the opposite direction and stops with the leading edge of the paper added, and at the time when the "manual feed command" is issued and IPREQφ (862) rises, the registration motor 149 rotates in the reverse direction again and moves the paper to the transfer position. It is designed to be conveyed until it stops. Therefore, if the "manual feed command" is about to be issued, it is possible to print on paper from the cassette.

The case shown in FIG. 59 is a case where paper is set in the manual guide after the [manual feed] mantle has come out first, and the manual field switch 326 is turned on. In this case, the registration motor 149 is continuously rotated in reverse to convey it to the transfer position. In both cases, the manual stop switch 328 is turned off.
Time t21 after a predetermined period has passed after F (time [20)
The registration motor 149 stops when the paper is loaded, so that "jumping" will not occur even if the paper set in the manual feed guide is longer than the displayed size. . In the case of cassette paper, such consideration is not necessary since the size is specified. Therefore, even if the cassette paper runs out, printing can be performed by preparing paper with 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. Equipment utilization increases.

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 number is executed via the test key. When maintenance mode is selected, the flow shifts to ■, and C is pressed via the test key.
When the specified No. maintenance mode operation is executed and the replacement mode is selected, the process moves to the flow shown in ■, and it is determined whether it is drum replacement or 1, developer replacement, or heat-low/replacement. , respectively [Drum characteristic No. set 1
, "Developer replacement NO set", [Heat roller N.

"Let" allows the non-volatile generation RAM 10 to be activated via the test key.
Predetermined data processing for 7 is performed.

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

(Hereinafter in the margin) [Effects of the Invention] As detailed above, according to the present invention, the following excellent effects can be achieved.

(1) Since the output monitor current of the semiconductor laser is controlled to be constant during the period when no modulation is performed, the light amount is quickly stabilized due to heat generation of the semiconductor laser itself, and extremely accurate High optical output can be stabilized.

(2) While the semiconductor laser is turned on, the current is gradually increased at a fairly slow time due to the function of the integrating circuit, so no abnormal current flows to the semiconductor laser, and the failure rate of the semiconductor laser increases. is significantly reduced.

(3) Since the optical output setting reference voltage and the optical output of the semiconductor laser are in a proportional relationship, accurate sales horn settings can be made.

Furthermore, when setting the light output using a light output adjustment system or the like, the output can be displayed in proportion to the rotation angle of the volume, so that the light m setting can be made accurately and easily.

(hereafter) margin)

[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 printing control unit (printer) in the system diagram, and Fig. 3 is a
Sea 1 earth ski 1 in the diagram? 4 is a schematic diagram showing the paper feeding section shown in FIG. 2, and FIG. 5 is a schematic diagram showing an example of the paper discharge section in FIG. 2. , FIG. 6 is a plan view showing the operation panel section of the device of the present invention, FIG. 7 is an enlarged plan view of the display section in FIG. 6, and FIG. 8 is a block diagram showing an example of the data control section in FIG. 1. Figures 9, 10, and 12 are format diagrams of data handled by the data control unit, respectively.
The figure shows the correspondence between the area of the recording section in the data control section and the paper.
Figure 13 is a block diagram of the print control section in Figure 1, Figure 14 is a detailed circuit diagram of each detector in Figure 13, and Figure 14 is a detailed circuit diagram of each detector in Figure 1.
Fig. 5 is a block diagram showing details of the drive circuit and output element in Fig. 13, Fig. 16 is a circuit diagram showing details of the motor drive circuit and laser scan motor in Fig. 13, and Fig. 17 is a block diagram showing details of the motor drive circuit and output element in Fig. 13. A detailed circuit diagram showing the modulation circuit and the semiconductor laser, FIGS. 18 and 19 are characteristic diagrams showing the relationship between the semiconductor laser and the optical output, and FIG. 20 is a time chart for explaining the operation of the circuit in FIG. 17. 21 is a detailed circuit diagram showing the beam detection circuit and beam detector in FIG. 13, FIGS. 22 and 24 are waveform diagrams for explaining the operation of the circuit in FIG. 21, and FIG. 23 (Δ), (
B) is a front view and 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, and FIG. 26 is a circuit diagram of the interface circuit in FIG. 13. 27 is a relationship diagram between command abbreviations and functions used in the device of the present invention, and FIG. 28 is an explanatory diagram showing the contents of status used in the device of the present invention,
Figure 29 is a relationship diagram of the beam scanning position and data writing position on the recording photoreceptor in Figure 3, and Figure 30 is a diagram of the relationship between the beam scanning position and data writing position on the recording photoreceptor in Figure 3.
31 and 32 are time charts for explaining the operation of the circuit in FIG. 25, and FIGS. 33 and 34 are for the paper Printing pattern diagram, Figure 35 and Figure 3
Figure 6 is a characteristic diagram showing the exposure position, exposure energy, surface N position, and the relationship between exposure energy and exposure position to explain the exposure control operation in the circuit of Figure 25, and Figure 37 is the high voltage for charging in Figure 15. Detailed block diagram of power supply, Part 3
8 to 41 are characteristic diagrams for explaining the operation of the circuit shown in FIG. 37, and FIG. 42 is a schematic diagram showing the relationship between the laser scanner 17 unit and the recording photoreceptor shown in FIG. 2. , FIG. 43 is an explanatory diagram showing the relationship between the recording photoreceptor and paper, and FIG. 44 is a modification of the paper ejection tray shown in FIG. 5.
45 (A>, (B)) and 46 are detailed diagrams of the data recorded in each recording device in FIG. 13, and a flowchart for explaining the data, and FIGS. 57 to 59 are detailed diagrams of the data recorded in each recording device in FIG. The time charts for explaining the operation and FIGS. 61 to 63 are relationship diagrams showing the display numbers and their contents on the device of the present invention. 232...Current-voltage changing means , 234...
...comparison means, 36...switching means, 257...
... Voltage-current changing means, 260 ... Photo detection means, 344 ... Semiconductor laser, R40, CO7 ... Integrating means. Figure 19 +3 (OFF) Yo, Ward, 7th Engineering Figure 42 Figure 43 Figure 63

Claims (1)

[Claims] (1) A photodetection means for detecting the optical output of a semiconductor laser, a current-voltage conversion means for converting the detected current from the photodetection means into a voltage proportional to the optical output, and a voltage from the current-voltage conversion means. and an optical output setting reference voltage, an integrating means that performs charging and discharging at a fixed time constant according to the binary output level of this comparing means, and a charging means for this integrating means. It has a voltage-to-current converting means for supplying a current proportional to the voltage to the semiconductor laser, and a switching means inserted and connected between the comparing means and the integrating means, and the switching means is connected during modulation of the laser. 0FFL, and the switching means is turned on during the previous period or a part of the period in which laser modulation is not performed.
A laser light amount stabilizing device characterized in that the laser light amount is stabilized and corrected.