JPH02547A - Device for formation of image - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a printing method such as a laser printer that includes a step of scanning a laser beam to form an electrostatic latent image on a photoreceptor. The present invention relates to an image forming apparatus suitable for use in apparatuses.

(Prior Art) In the case of this type of conventional image forming apparatus, as shown in FIG. 25, for example, the printing side 1 is constituted by a printer 2, and the host side 3 is constituted by a controller 4. Then, by sending a status signal from the printer 2 to the controller 4 and sending a command from the controller 4 to the printer 2, the system status can be checked based on the system status. The command is sent to control the printer 2. In addition, when controlling the printer 2, the printer 2 outputs a horizontal synchronization signal to the controller 4, and the controller 4 outputs a horizontal synchronization signal.
is configured to send a video data signal to the printer 2 based on the horizontal synchronization signal.

However, when sending a video data signal from the controller 4 of the host 3 to the printing side 1, the printing side 1
Since the video data signal was sent out based only on the horizontal synchronization signal output from the printer, the recording start position of the paper sometimes became inaccurate.

(Problems to be Solved by the Invention) In other words, in the case of the conventional image forming apparatus, the recording start position of the paper is simply indicated from the host side based on only the horizontal circumference 1-ga signal output from the printing side. Since the video data signal is sent to the printing side and the printing side starts recording on the paper, there is a problem that the recording start position on the paper may become inaccurate.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus that can accurately determine the recording start position 5 on a sheet of paper.

[Structure 1 of the Invention (Means for Solving the Problems) In order to achieve the above object, the present invention comprises a printing side and a host side that sends various data signals to the printing side. A video clock signal synchronized with the recording start position of the paper is output from the host side, and based on this video clock signal, sending of the video data signal from the host side to the printing side is started.

(Function) With this configuration, the video data signal is sent from the host side to the printing side based on the video clock signal from the printing side that is synchronized with the recording start position of the paper, so the video data signal from the host side is There is no difference in the transmission start timing. Therefore, it is possible to accurately determine the recording start position of the paper on the printing side.

(Embodiment) FIG. 1 is a block diagram schematically showing an embodiment of an image forming apparatus to which the present invention is applied.

The image forming apparatus of this embodiment has two colors L constituting the printing side.
The BP 199 and the post system 500 (external devices such as a computer and a word processor) are coupled via a transmission controller (interface circuit, etc.) not shown. The two-color LBP 199 is connected to the host system 50.
0 receives two types of dot image data, modulates each of the two laser beams to execute writing on the photoreceptor (image carrier), and writes the two types of written dot image data independently. The image is developed and transferred onto recording paper.

That is, this two-color laser beam printer (LaserB
In the all printer printer (hereinafter referred to as two-color LBP) 199, a first charger 2 is provided around the photoconductor 200 as shown sequentially along the rotation direction indicated by the arrow.
01. Table 1 100 Lightning Level Sensor 202. First developer 203.
Second charger 204. Table 2 100 Lightning Level Sensor 205. Second developer 206. Pre-transfer charger 207, transfer charger 208.
Peeling charger 209° cleaner 210 and snow remover 211
is arranged, and Table 1 100 Lightning Level Sensor 202
The second laser beam 310 is irradiated onto the photoconductor 200 between the first exposure device 203 and the first exposure device 203 to perform the first exposure.
The second sensor is located between the table top level sensor 205 and the second current @ device 206.
A laser beam 310 is irradiated to perform a second exposure.

Further, the control section of the two-color LBP of this embodiment has a block configuration as shown in FIG.

The control unit of this two-color LBP has a CPU 501 as the control center, a ROM 502 in which a system program is stored, a ROM 503 in which a data table is stored, a RAM 504 used as a working memory, a timer 505, and an I10 data input. Output Eiiff506 and
It basically includes a print data write control circuit 513 and an interface circuit 519.

The contents of the data table stored in the ROM 503 are as shown in FIG.
contains first color top margin control data and address (4
002) and (4003) contain second color top margin control data, and addresses (4004) and (4005) contain left margin control data.

Addresses (4006) and (4007) contain bottom margin control data for paper size A3, and address (400
8) (4009) contains data for controlling the light margin of the same paper size. Below, tables corresponding to various paper 1 noises are similarly included up to address (4083).

From address (4090), data for top margin coarse adjustment, from address (40BO), data for top margin fine adjustment, from address (40DO), data for left margin coarse adjustment, from address (4100), for left margin fine adjustment. Data and address (4120) contain two-beam scanning length correction data, which correspond to switches 1 to n, respectively.

These margin control data, coarse adjustment data, and fine adjustment data are used as set data for a margin control counter and a binary counter of a print data write control circuit 513, which will be described later.

Addresses (6000) (6001) are the first development bias data for red 1 to tone, and address (6002) (
6003) contains second development bias data.

Below is the first toner, green toner and black toner. Similarly, second developing bias data is included up to address (600F), and is used as set data for developing bias control of the wrestling control circuit 522, which will be described later.

Is address <6100) (6101) the target surface for first charging potential control? Contains H-rank table data, 25
It becomes the base Q value of ゛C.

Addresses (6102) and (6103) contain error table data at the time of convergence, and allowable control 11g! for the above target surface potential! Represents the surrounding area.

Addresses (6104) and (6105) contain initial control output table data, which is the set value of the first electrification charger that is output at the beginning during warming up.

Addresses (6106) and (6107) contain minimum correction table data.

Address (6108) (6109) is surface potential limit table data, address (610A) (610B> is control output upper limit table data, address (610G) (
610D) contains 1IIIll output lower limit table data, and the surface potential limit table data, the control output upper limit table data, and the control output lower limit table data are used for self-diagnosis of the control system.

Below, the table corresponding to the second charging potential control similarly contains up to address (611B>. Address (6120
) contains charging potential temperature correction table data in the temperature range of 10°C to 40°C, which serves as temperature correction data for the target surface potential table data of 25°C.

A timer 505 is a general-purpose timer and generates basic timing signals for vlWJ such as paper conveyance and photoconductor rotation processes.

The input/output device 506 outputs display data to the operation display section 507, inputs various switch data, etc., inputs the aIII control section internal output device 508, and outputs the motor.

Output to a drive circuit 509 that drives drive elements 510 such as clutches and solenoids, output to a drive circuit 511 that drives a laser scan motor 512 for scanning two laser beams, detection of potential sensors, temperature sensors, etc. Input/output is performed for the process υ1111 circuit 522 that controls the output of the high voltage power supply 523 and the like in response to the input of a signal.

The print data write control circuit 513 includes a first laser modulation circuit 514 that performs optical modulation of the first semiconductor laser 302 for writing image data of the first color, and a second laser modulation circuit 514 that performs optical modulation of the first semiconductor laser 302 for writing image data of the first color. A second laser modulation circuit 521 that performs optical modulation of the semiconductor laser 303 is driven and controlled to write print data of the video image transferred from the host system 500 to a predetermined position on the photoreceptor. At this time, the beam detector 518 using a high-speed response PIN diode detects one of the two light beams being scanned by the laser scan motor, and the beam detection circuit 517 detects one of the two light beams being scanned by the laser scan motor. The analog signal from 518 is digitized by a high-speed comparator to create a horizontal synchronizing pulse, which is sent to print data write control circuit 513.

The interface circuit 519 connects the host system 500
It outputs status data to the host system 500 and receives command data and print data from the host system 500.

Also, these are i! A power supply device 520 is provided to supply power to each part of the i control section.

Details of the main blocks in FIG. 2 will be explained below.

FIG. 4 is a diagram showing details of interface signals between the interface circuit 519 and the host system 500 in FIG. 2. In the figure, 07-Do is an 8-bit bidirectional data bus, [DSTA is the data bus selection signal, and is used as a status data bus to the host system 500 or a command data bus from the host system 500. choose whether to do so. l5
TB is a strobe signal for latching the command data in the interface circuit, and fBSY is a signal for permitting transmission of the strobe signal 15TB and for reading status data.

IH8YNI is print data 1 with the horizontal synchronization signal of the first color.
Request a line to be sent.

IVCLK1 is a video clock signal for the first color and requests transmission of one dot of print data.

IPENDI is the page end signal of the first color and notifies the end of the line.

Post system 500 is kanki IH8YNI, IV CL
Based on K1, the video data signal IVDAT1 of the first color dot image data is sent out, and IPEND1 is sent out.
When it receives, it stops sending.

Similarly, IH8YN2 is the second color horizontal synchronization signal, IVC
LK2 is the second color video clock signal, IPEND2
is the second color page end signal, and the host system 50
0 is the video data signal IVDA of the second color dot image data based on the IH8YN2 and IVCLK2.
It transmits T2 and stops transmitting when it receives IPEND2. This video data transmission MIVDATI, IVDA
T 2 +, t r (sent to the J-shaped data circulation control circuit. The above relationship is shown in FIG. 5.

IPRDY is a signal indicating that the two-color LBPI 99 is ready, and IPREQ is a signal for the host system 500.
IPRME is a prime signal that initializes the two-color 1-BP 199, and IPOW is a signal that informs that the two-color L[3P 199 is energized.

Next, details of commands and statuses used in the two-color LBP 199 are shown in FIGS. 6 and 7, respectively.

In FIG. 6, SRI to SR7 are status request commands corresponding to statuses 1 to 7 in FIG.
is the cassette upper paper feed specification command, C3TL is the lower paper feed specification command, and VSYNC is the host system 500 command.
A command that specifies the start of sending print data, SPl
, SP2. DPl is a command that specifies the print mode,
SP1 is a mode that specifies a printing operation for only the first color, SP2 is a gJ-shaped operation for only a second color, and DPI is a mode that specifies a printing operation for both the first color and the second color. MFI to 9 each indicate a manual feed mode designation command.

In FIG. 7, during paper transport, paper is being fed 2
A status indicating that paper is being transported within the color LBP 199. A vSYNC request is a status indicating that the two-color LBP 199 has received a command to start printing and is now ready to receive print data. For manual feed, the paper feed mode is manual feed. The status indicates that the upper/lower cassette is in the selected cassette in the cassette paper feeding mode, and the print mode is 1st color, 2nd color, 2nd color.
The color is the status indicating the selected print mode,
The cassette size (upper row) and the power hit size (lower row) are the statuses that indicate the size code of the cassette installed in the device, and the toner color (first color) and toner color (second color) are the toner of the installed developing device. The color code is the status indicating the size, Test/Maintenance is the status indicating that it is in the test/maintenance state, Data resend request is the status indicating that reprinting is necessary due to a jam, etc. During the wait, the two-color LBP is connected to the fixing device. The status indicating the A-home up state and operator call indicates that an operator call factor of status 5 has occurred.

Serviceman call indicates that a serviceman call factor of status 6 has occurred. Toner bag replacement indicates that the toner bag is full. Out of Paper indicates that there is no paper in the specified cassette.
Paper jam ↑・mu indicates that paper has jammed inside the machine. No toner of the first color indicates that there is no more toner in the first developer.No toner of the second color indicates that there is no more toner in the second developer.The failure of the second laser indicates that the second laser diode A second laser failure indicates that the second laser diode does not reach the specified output, or the beam detector is unable to detect the beam. Scan motor failure is caused by scan motor! The first potential sensor failure and the second potential sensor failure indicate 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 the specified number of rotations, respectively. The number of sheets to be retransmitted does not indicate the number of sheets that need to be reprinted when the data retransmission request status occurs.

FIG. 8 is a detailed circuit diagram C of the first laser modulation circuit 514, first semiconductor laser 302, second laser modulation circuit 521, and second semiconductor laser 303 in FIG. First, the first loser modulation circuit 514 and the first semiconductor laser 302 will be explained.

In FIG. 8, 302 is a first semiconductor laser diode, which is composed of a laser diode 812a that emits light;
It consists of a monitoring photodiode 811a that monitors the output beam intensity from the laser diode.

809a is a high frequency transistor and a losser diode 8
12a is optically modulated. A resistor R29a is a current detection resistor, 810a is a transistor for passing a bias current to the first loser diode 812a, R30a is a current limiting resistor thereof, R27a is a base current limiting resistor of the transistor 810a, and 817a is an inverter. Inverter 8
The input of 1a is a losser diode enable signal LDO.
NIO is input, and when this signal becomes LOW level, the transistor 810a turns ONt, and a bias current flows through the loser diode 812a. 80
7a and 808a are high-speed analog switches for applying modulation to the first diode 812a, and each analog switch connects the gate (G) to the drain (D) when a voltage of Source (S)
The resistance between the two becomes low and the ON state is reached. When a LOW level voltage is applied to the gate (G), it becomes high resistance and turns OFF.
become a state. R21a is an analog switch 807a,
Short-circuit protection resistance during 0N-OFF change of 808a, 813
a, 814a are the above log switches 807a, 8
This is the 08a gate driver. C02a, C03
a is a speed-up condenser, R24a, R2
5a is an input resistance of the gate drivers 813a and 814a. 815a and 816a are EXCLUS I
It is a VE-OR gate and changes depending on the output of the 2AND gate 820a. The 2AND gate 820a outputs 1 when either of the two gate inputs becomes LOW level.
fi L OW L/ H/L, l, :Nari Mki EX
CLUSIVE-OR gate 815a output is LO
The level becomes W, and the analog switch 807a is turned on.
Then, the first loser diode 812aG enters the tON state.

The condition that the output of the AND gate 820a becomes LOW level is that the first video data signal IVDAT10 is LOW.
level or the first sample signal SAMP10 is L
This is when the level is OW. When the inputs of the 2ΔND gate are both at HIGH level, the EXCLIJS I
The output of the VE-OR gate 816a becomes LOW level, the analog switch 808a is turned on, and the VE-OR gate 816a is turned on.
The diode 812a is turned off.

806a is an operational amplifier, which constitutes a voltage foo 07 circuit. DOl is a Zener diode.
The output of the diode 812a is regulated to be within the maximum rating. Further, the resistors R19a and C01a constitute an integrating circuit, and R20a is a discharge resistor that discharges the charge of the capacitor C01a at a constant rate. 804
A is an analog switch whose gate (G) is connected to an inverter 805a, and the first sample signal SAMP10 is input to the input of the inverter 805a. 803
a is a transistor for level conversion, R22a is a base current limiting resistor of the transistor 803a, and R18a is a current limiting resistor for charging the capacitor C01a. 802a is a comparator, and this comparator has hysteresis characteristics due to the movement of resistors R14a and R15a.

The resistor R14 is connected to the input side of the comparator 802a.
The output voltage of the first router monitor multiplier 801a is applied through a. 801a is a losser diode 812
This is an amplifier for the output of the photodiode 811a that detects the optical output from the photodiode 811a. Resistors R12a, R13a, V
ROla is a resistor that regulates the amplifier of the operational amplifier 801a. Therefore, by changing VROla, the amplifier of the operational amplifier 801a can be changed.

R11a is a load resistor for the output of the photodiode in the first loser diode, and a voltage proportional to the output current of the photodiode 811a is obtained across the resistor R11a. Since the output current of the photodiode 811a is proportional to the optical output of the laser diode 812a, the optical output of the laser diode 812a can be adjusted by varying the volume VRO1a.

Reference numeral 818a is a humpator for checking whether or not the first loser diode is emitting light, and the output voltage of the operational amplifier 801a is applied to the negative input. Further, a voltage divided by resistors R16a and R17a is applied to the + side input.

Therefore, when the first loser diode 812a emits light and its output exceeds the voltage divided by the resistors R16a and R17a, the output level of the comparator 818a becomes H.
The level changes from the IGH level to the LOW level, and the Loser Ready signal LRDYIO is output.

Further, a laser optical signal setting voltage is applied to one input terminal of the comparator 802a. The output of the voltage follower 819 is applied to the set voltage. The exposure adjustment volume 8 is connected to the input terminal of the voltage follower 819.
21 and resistor R31 is input, and by varying the exposure adjustment volume 821, the output voltage of the voltage follower 819 also changes.

Next, the first loser modulation circuit 514 and the second loser diode 30
The second operation will be explained. First, when the first loser diode enable signal QLDONIO reaches the 10W level, a bias current flows through the first loser diode 812a. Next, the first
When the sample signal @SAMPIO goes to LOW level,
Analog switches 804a and 807a are turned on, but
Since capacitor C01a is not charged, the output of voltage follower 806a is Ov.
The modulation transistor 809a is not ONL. Therefore, a current flows through the first loser diode 812a to such an extent that no light is emitted. At this time, since no current flows through the first photodiode 811a, the output of the comparator 802a becomes LOW level and the transistor 803a is turned off, so that the capacitor C○1a is charged through the resistors R18a and R19a. When charging (resistance R18a, R19a, capacitor C○1a
The time constant is selected to be approximately 20 to 5 Qmsec.

If this value is very small, the response of the stabilization circuit will be too fast,
Fluctuations in the laser light output level become large. Moreover, if it is too large, the responsiveness will deteriorate and it will take time for the optical output to stabilize. As the capacitor C01a is charged, the output pressure Tj of the voltage follower 806a also gradually rises. Therefore, as the base voltage of the Ray If modulation transistor 809a increases, a current flows to the collector.

The transistor 81 is connected to the first loser diode 812a.
A summation current of the bias current from 0a and the collector current from the transistor 809a flows, and when the sum of the currents exceeds the threshold current of the th loser diode 812a, the th loser diode 812a emits light. No. 1 rule
When the diode 812a emits light, a current flows through the first photodiode 811a for the 72-channel transistor, and the voltage at the t input terminal of the A-72 sensor 801A exceeds its output phase 1. [The value obtained by increasing the input voltage by 1J is output. When the output voltage of the A-subjective 801A becomes equal to or higher than the voltage divided by the resistors R15a and R17a, the output 1) of the comparator 818a and the second settler ready signal LRDY10 become HI.
The level changes from GH to LOW. and comparator 80
When the output voltage of the operational amplifier 801Δ becomes higher than the first input terminal voltage of the input terminal 2a, the output of the comparator 802a changes from LOW to the 1-11 G torque level, and the transistor 803a turns ON. Capacitor C01a is discharged through resistor R19a. Therefore, the base voltage of the modulating transistor 809a also decreases, and the optical output of the first looper die A decreases. When the optical output of the second looper die A decreases, the small input terminal voltage of the comparator 802a also decreases. When the voltage of the laser beam becomes lower than the set voltage, the transistor 803a is turned off again, and the resistor R18a is connected to the capacitor C01a again.

It is charged up through R19a. In this way, when the optical output of the first loser diode 812a reaches the final set voltage for the first loser light, the comparator 802a slowly repeats ON-OFF at around the set voltage for the first loser light 8. The optical output of the second Ruji die A-de 812a is stabilized.

When the CPIJ501 confirms that the loser ready signal LRD Y10 has become LOW level via the I10 port, it starts the operation of the sample timer described later, and prints the first sample every line outside the printing area. The analog switch 804a sets the signal SAMPIO to the LOW level for a certain period of time.

Turn on 807a to stabilize the amount of laser light.

Next, when the two-color LBP 99 becomes ready for printing and the first video data signal VDATIO is sent from the host system 500, the first video data HQVDATIO
The analog switches 807a and 808a alternately turn ON and OFF in response to
The first loser diode 812a is modulated by a, and dot image data is applied to the photoreceptor 200.

The second laser modulation circuit 514 and the first semiconductor laser 4f
Although the details of 302 have been described, the second laser modulation circuit 5
21 and the second semiconductor laser 303 have similar configurations,
The output of the voltage follower 819 is applied to the light intensity setting voltage of the second laser diode 812b, that is, the input terminal of the comparator 802bk. Therefore, by varying the exposure adjustment volume 821, the output voltage of the voltage follower 819 also changes, so the voltage at one input terminal of the comparators 802a and 802b changes simultaneously. Therefore, the optical output of the first laser diode 812a and the optical output of the second laser diode 812b are adjusted to the exposure volume 8.
21 can be adjusted at the same time by making them variable.

FIG. 9 is a detailed circuit diagram of the beam detection circuit 517 and beam detector 518 in FIG. 2. In Figure 9, 5
18 is a beam detector that uses a PIN diode with very fast response.

Furthermore, this beam detector 518 serves as a reference pulse when writing print data onto the photoreceptor 200, and the generation position of this pulse must always be stable.

The anode side of the beam detector 518 is connected to one input terminal of a high speed comparator 825 through a load resistor R41 and a resistor R44. Further, a voltage divided by resistors R42 and R43 is applied to the child input terminal of the high-speed comparator 825 through R45. Further, a capacitor C10 for noise removal is connected in parallel to the resistor R43. In addition, R46 is designed to have hysteresis characteristics.
The positive feedback resistor C11 is a feedback capacitor for applying feedback at high speed to improve the output waveform.

Next, the operation will be explained. When the laser beam passes over the beam detector 518 at high speed, a pulse current flows through the beam detector 518, and a positive pulse voltage is generated at one input terminal of the comparator 825.

This pulse voltage is compared with the + side input terminal voltage of the comparator 825, and a negative pulse l-ISYO is outputted from the output of the comparator 825.

FIG. 10 is a diagram showing a one-time scan range of the laser beam on the photoreceptor 200 and the positional relationship of beam detection positions, data writing positions, etc. within the range.

In FIG. 10, 900 is the beam scanning start point, 901 is the beam scanning end point, and the beam that has reached the beam scanning end point 901 is moved by the next surface of the polygon mirror to the next beam from the beam starting point 900 at time O. Start. 902 indicates the beam detection starting point of the beam detector 518; 903
9 shows the right end surface of the photoreceptor, and 910 also shows the right end surface. 904 represents the left end surface of paper, 909 represents the right end surface of paper size A3, and 907 represents the right end surface of paper size 80.

905 is the data writing start point, 908 is the paper size A3
The data writing end point 906 represents the data writing end point of paper size A6.

dl is the distance from the beam detection point 902 to the writing start point,
d3 represents the distance to the A6 size writing end point and d4 represents the distance to the A3 size writing end point. Also dl
does not represent the range of constant strain in the beam.

d5. d6 indicates the effective printing range in 80 and A3, respectively. As can be seen from this drawing, the paper feed of this printer always feeds the left end surface of the paper 1 full, so the printing start point 905 from the beam detection device 902 is the same for each paper size. Therefore, data may be loaded after a period of time corresponding to the distance from the beam detector 518 detecting the beam to the writing start point.

FIG. 11 shows the paper size and print area portion of FIG. 10 not only in the horizontal direction but also in the entire paper.

In FIG. 11, 917 represents a 6-sheet set, and 918 represents a △3 sheet. 904,905,906゜907.908
, 909 show the same positions as in FIG.

911 is the leading edge of the paper, 913 is the vertical data writing start point, 912 is the trailing edge of the A3 size paper, 916 is the A
Indicates the end point of data writing for 3 sizes. Reference numeral 915 indicates the trailing edge of the paper for size 6, and 914 indicates the end point of data writing for size A6.

Figure 12 shows the print data reading control circuit 51 in Figure 2.
FIG. 3 is a detailed circuit diagram of No. 3. This print data writing control circuit 5
The main function of 13 is a laser modulation circuit 51 for writing print data from the host system 500 into a predetermined area on the photoreceptor 200 according to the size of the paper to be printed.
4. Send on 521. Further, the laser modulation circuit 514,
The necessary signals are sent to the laser light output stabilization circuit of 521. It also sends timing signals necessary for sending print data to the host system 500.

In FIG. 12, 830 is a laser modulation circuit 514.5.
This is an input/output port for sending and receiving signals necessary for control within the 21 and print data write control circuit 513. The counter 831 is composed of a counter 1 timer that controls printing data writing, laser light output sampling, etc., and the setting of the operation mode and the preset value of the counter 1 timer can be programmably performed by the CPU 501. be.

865 is a laser light output sample timer and gate manual G6
Beam detection signals H8Y and D, which are the outputs of the beam detector circuit 517, are input to
The timer operation starts after 8Y○ changes from LOW to HIGH level, and the timer operation is set to end before the beam detector 518 for detecting the next beam.

Therefore, each time the beam detection signal H8YO is input to the gate input G6, the tie v't'r 65 is activated. The clock CK6 of the timer 865 is 1500KH.
2 clocks are input. The output SMPTD of the timer 865 is input to one of the 2OR gates 877,
The output of the 2OR gate 877 is the first sample signal SA.
MPIO, the second ripple signal esAMP20, and the second loser modulation circuit 514. Second laser modulation circuit 517
through 2NAND gates 886 and 887.

The other input of the 2NAND gate 886 is the output router die auto enable signal Ml- of the I10 port 830.
DON11 is input so that a3 can independently inhibit the first sample signal SAMP10. Similarly, the two laser diode enable signals LDONZ1
is input, and the second number signal SAMP is input to Germany rt.
20 can be prohibited. Similarly, the 2N
The other input of AND gate 887 is I10 port 830.
output second laser diode enable signal LDON2
1 is input, and the second sample signal SAMP is input independently.
20 can be prohibited. Further, the output curry ff test signal 1-0 signal S1 of the I10 boat 830 is input to the other input of the 2 OR gate 877, and by setting the laser test signal LDTS1 to the 1-(IGH level), The first semiconductor laser 302 and the second semiconductor laser 303 can be forced to emit light.I
The 10th port t-830 receives the loser ready signal LRDY1.
0, the second laser ready signal LRDY20 is input, and in the forced emission state of each laser, the first laser ready signal LRDY20 is input. By determining the second laser ready signal, it is possible to determine whether each laser is emitting light.

866 is a 0-type F/Ft' that generates a line start signal LSTI, beam detection (No. 9 1-ISYOF is set, and is reset at the rise of the sample timer output SMPTO. 867 is a beam detection ready signal LD).
It is input to the I10 port 830 through a D-type F/F that generates OTI. [Above]] Type F/F866.867L, t2
It is also reset by the OR gate 869+7) output. The human power of 2 OR Goo 1-869 is the first. A second laser diode enable signal.

A crystal oscillator 832 serves as a reference clock for image clock pulses, and its oscillation frequency is approximately 32 MHz. 834,
835 constitutes a quaternary counter with J-KF/F,
The output of the crystal oscillator 832 is rotated by 4 minutes to generate a first video clock VCKX21 (approximately 8 MHz>) corresponding to the minimum modulation unit of one dot of the laser beam.

837.838 is the same J-KF/ as 834.835 above.
F constitutes a quaternary counter, but JKF/837
An n-bit binary counter 845 is input to J- of
A carry-out output CO is inputted via an inverter 846.

In J-KF/F834, 835, 837, 838, when the input to J- is at the 111GH level, its Q output performs a toggle operation in synchronization with the clock input GK, and the input to J- is L.
When it reaches the OW level, the Q output ()j interrupts the toggle operation. As a result, the Q of J-KF/F838 in the latter stage
The output second video cloak key No. 3 VCKY21 has a pulse interval of "1" during normal operation, and when the n-bit binary counter 845's carrier ratio 1-output CO occurs, it becomes [5/4J and 1/4 clock. (This means that the n-bit binary counter 8
45 preset inputs DO to Dn have n-bit latches 8
47 main Qo to QO are connected, and the setting value thereof can be set by the CPU 501 according to [)ip-sw, etc. The above setting value is for 1 line (LST)
The carry-out number of the n-bit binary counter 845 is set where l is between 1-110 + - levels), and as a result, the number of clocks r5/4J is generated. Inverter 839. The shift register 840°2NOR gates 841 and 842 are circuits that provide the n-bit binary counter 845 with a predetermined operation.

The second video clock signal VCKY21 is used to correct the difference in scan length fL+, 12 of the two laser beams. In this case, the first video clock VCKX21. The second video clock signal VCKY21 may be designated and shifted for the laser beam with a short scanning length. 848 is a selector that specifies the output CHGCK of the I10 boat 830.
This is done by

Next, a correction method will be explained using an example. For example, if laser beam 1 with a long scanning length is 200 mm and laser beam 12 with a short scanning length is 199 mm, the difference in scanning length is l.
It becomes 11m. 2 when the wI image resolution is 12 lines/mm.
It is sufficient to extend the video clock signal VCKY21 of the laser beam A2 having a short scanning length by 12 dot clocks after 400 dot clocks (200×12). Here, in one correction, the dot clock is enlarged by 1/11, so
During 2400 dot clocks, 1/4 dot clock correction is performed 12×4=48 times.

Therefore, in the n-bit binary counter 845, the output clock input CP of the n-bit binary counter is 1/
Because it is a 4-dot clock, its key! It is sufficient to output 48 outputs while counting 9600 (2400x4) clocks. That is, every 200 counts, 1
It is best to set the preset value so that the noise will not occur.

836 is a binary counter and its Q2 output 1-I CT
31 C. An 8-dot clock (approximately IMI-1z) obtained by dividing the first video A clock VCKX21 by 8 is output.

Reference numeral 863 is a reflex 1~margin counter that sets the starting point including data 1B from the beam scanning starting point.

864 is a write margin counter that sets the data writing end point from the beam scanning start point. The line start signal LSTI is applied to the gate input G4 of the left margin counter 863 and the gate input G5 of the left margin counter 864.

Clock manual CK of the left margin counter 863
4 and the clock input CK of the write margin counter
The 8-dot clock NCT31 is input to 5. Both counters can simultaneously correct fluctuations in the data writing start point and data writing end point due to mechanical installation errors of the beam detector 518. The correction of the error can be adjusted in units of 8 dot clocks by changing the settings of both counters according to DIR-3W or the like. The reason for setting it in units of 8 dot clocks is that even if the data writing start position and data writing end position on the paper deviate from 8 dots to 1, it is within the permissible range, and moreover, the above-mentioned error can be easily adjusted. It's for a reason. The setting value of the write margin counter described in 11.eta. changes depending on the paper size.

875 is a 2ΔND gate whose one input is the output LMCTO of the left margin counter 863.

The other input is the output R of the write margin counter 864.
MCTO is input via an inverter 874,
Therefore, the output j of the 2AND gate 875 represents the horizontal printing area.

The output of the 2AND gate 875 is sent to the shift register 86.
8, the horizontal printing area signal 1-(PEN1) is output from the Q output.

The horizontal print area signal 1-IP E N 1 is input to the CE input of the n-bit binary counter 850 and the shift register 854 . The n-bit binary counter 850 and the 2NAND gate 849. n bit latch 8
51. J-KF/F852 has a circuit configuration that can shift the data infiltration start point to the right in units of one dot.
The output of F/F852 is the first horizontal printing area signal 1-I
Output P E N B 1. The Bricht manual DO~Qn of the n-bit binary counter 850 sets the shift number for right shift, and is connected to the output of the n-bit latch 851.
A value can be set according to pSW etc. The shift register 854 and shift register 855. The inverter 853 has a circuit configuration that shifts the horizontal print area signal HPENI to the right by two dot clocks, and the shift register 8
The output of 55 is the second horizontal printing area signal 1-I P E
Output NA3. This is the first horizontal printing area signal H.
This is because even if PENB1 is at its minimum setting value, it is shifted to the right by two dot clocks.

The output of the AND gate 857 is a first video clock signal QVC indicating the video clock signal for the first horizontal printing area decrement.
One of the inputs of LKBIT:, AND'j-to 857 is the first horizontal print area signal TRIPEN81. The other is the Y1 output of the selector 848. Also, AND gate 85
The output of 6 is the second video clock signal VCLKA1 indicating the video clock signal for the second printing area decrement, and one of the inputs of the AND gate 856 is the second horizontal printing area signal H.
PENA 1 and the other is the Y2 output of the reflector 848.

As described above, the first horizontal print area signal HPENB1. The first video clock signal VCLKB1 is used to correct errors in the scanning start points of the two laser beams. In this case, the second horizontal printing area signal HPENΔ1. Second video clock signal V
CLKA1 is specified, and the first horizontal printing area signal HPENB1. 1st bidet A
It is sufficient to specify the clock signal VCLKBI and adjust the error d.

The filleter 858 is a selector that performs the predetermined selection (this is performed by the output CHG12 of the /◯ boat 830).

859 to 862 are counters for setting the data write start point and data write end point in the vertical direction (paper advancing direction); 859 is a first page top counter for setting the data write 17fl start point for the first color; 8601 is the first page end counter that sets the data write end point for the first color, and 861 is the second page end counter that sets the data write start point for the second color.
The page top counter 862 is a second page end counter that sets the end point of data writing for the second color.

Gate inputs GO to G3 of each counter 859 to 862 have a page top signal PT which is the output of the I10 boat 830.
OPI is connected. It is activated by the 5YNC command.

Clock inputs CKO to CK for each counter 859 to 862
3 is connected to the line start signal LS1,
As a result, it is possible to count in units of one scanning line (in units of one dot). The method of setting each counter will be described later.

871 is a 2AND gate, one input is the output PECT10 of the first page top counter 859, and the other input is the output PECT1 of the first page end counter 860.
Therefore, the output of the 2AND gate 871 becomes the first color vertical print area signal VPEN11.

873 is a 2AND gate, one input is the output PTCT2O2 of the second page top counter 861, and the other input is the output PECT2 of the second page end counter 862.
O is input through the inverter 872, so the output of the 2ΔAND gate 873 becomes the second color vertical print area signal @VPEN21.

Output of the 1st page end counter 1) E CT1
0, the output PECT2O of the second page end counter is I
The first color page end signal 11) ENDIO is input to the 10 boats 830 and the counting operation is completed.
, the second color page end signal ■PEND20 is sent to the host system 500.

878 is a ZNAND gate that sends the first color horizontal synchronization signal 1l-ISYNlo, and 879 sends the second color horizontal synchronization signal IH3YN20 to the host system 500.

880 is the first color video clock signal IVCLK
10, and 881 is the second color video clock signal rVc.
2NAND to send LK20 to host system 500
It is a gate.

884 is a 3N circuit that sends the first color video data signal rVDT10 from the host system 500 to the Luer modulation circuit 514 as the first video data signal VOATIO.
It is an AND gate.

885 is 3N which sends the second color video data signal IVDT20 from the host system 500 to the second laser modulation circuit 521 as the second video data signal VDAT20.
It is an AND gate.

888 is an inverter that sends a first loser diode enable signal LDON 10 to the first loser modulation circuit 514;

889 is an inverter that sends the second laser diode enable signal LDON20 to the second laser modulation circuit 521.

FIG. 13 shows a timing chart of the main signals for one page in the two-color printing mode, and FIG. 14 shows a timing chart of the main signals for one line.

Next, the operation of each part that operates in response to the control command issued from the control 0j8Ii of the two-color LBP 199 is shown in FIGS. 15 to 24.
A detailed explanation will be given according to each flowchart shown in the figure.

FIGS. 15 to 19 are flowcharts showing the overall operation of the 2eLBP.

In Figure 15, we are accepting self-diagnosis and warming-up treatments for the two-color LBP199.

In FIG. 15, the operator turns on the power supply 520.
Then, the system program stored in the ROM 502 starts, and first, the self-diagnosis process of AlO4 from step 101 is executed, and the door switch is turned ON (step A101 negative) door 'A-bun process (step Δ
105), the jam is cleared by turning on the 17F m switch, turning on the manual stop switch, and turning on the pass sensor.
Step C becomes 106).

Then, if it is not the test print shade and maintenance mode (steps 107 negative, 108 negative), the heater lamp that heats the constant 1i 221, which takes a relatively long time to reach the ready state, is turned on (step iii>,
Warming-up processing is started, and then the fixing device 221
motor and scan motor 512 are turned on (step A112). Note that if the mode is to test print 1 (Yes at step 107), a test print process is executed (step A109), and if it is a maintenance mode, a maintenance process is executed (step A110).

When the scan motor 512 is turned on and becomes ready (step A113 affirmative), the blade solenoid is turned on (step A114). Note that if the scan motor 512 does not become ready even after 30 seconds have passed since it was turned on (step A113 negative, A115 positive), trouble processing for the scan motor 512 is performed (step 116).

After the subsequent delay processing (step 117), the drum motor of the photoreceptor 200, the developer motor 425, the clutch of the first developer 203, the clutch of the second developer 206, and the snow remover 21
Each of the lamps of No. 1 is turned on (step 118), and through delay processing (step 119), the lamps of No. 1 are turned on (step 118).
02, 2nd laser diode 303, laser dest, pre-transfer band? Each of the E devices 208 is turned on (step Δ120).

After the subsequent delay processing (step △121), the loss-the-die A
- Determine the failure of the code 302 and the second laser diode 303 using the monitor.Steps A122 and AI23)
, if normal (step A122 affirmative, step A1
23 Portrait), the horizontal synchronization signal H3YNC is used to check whether these beams are ready for detection (step A128). In addition, the first rule
If the adapter 302 is out of order (step 122
If the second laser diode 303 is in failure (No), the first loser failure process (step A124) is executed, and if the second laser diode 303 is in failure (
Step 123 (No), and second ray +1 failure processing (Step AI 25) is executed. In addition, horizontal synchronization signal H3
If the beam is not detected at YNC (No in step 126), beam detection failure processing (step A127) is executed.

After the subsequent delay processing (step A129), the stripping charger 20
9 /fi ON satt (su-j ybuAl 30
) and delay processing (step A131), potential control during warming up as shown in FIG. 70 is executed (step A132). Note that step A132 is a process for enabling printing as quickly as possible during the first printing.

After the subsequent delay processing (step △133), step A1
The process advances to steps 34 to A140. That is, step A13
4, the transfer charger 207. Transfer strip? [Vessel 208. Each of the stripping chargers 209 is turned off. Step A13
6, the developer motor 425, the clutch of the first developer 203, the clutch of the second developer 206, and the first charger 201;
．． Each of the second chargers 204 is turned off. Step A
138, the drum motor of the photoreceptor 200, the static eliminator 21;
1. Loser diode 302. Second laser diode 303. Each of the motors of the fixing device 222 is turned off.

Step A 140 t- is when the blade solenoid is OF
F is given.

Thereafter, when the fixing device 221 becomes ready (step 141 is affirmative), the self-diagnosis and warming-up processes in steps A101 to A141 are completed, and the tenth
Proceed to the routine shown in the figure.

FIG. 16 shows two colors L 13 for the host system 500.
Reports the status of each part of P 199 and reports the status of each part of the host system 50.
0 shows the process of issuing a request to [pudding] when the status of each part is determined to be normal.

In FIG. 16, first, a determination is obtained from the host system regarding the contents of status 5 (steps A142 to A1).
45). That is, in step A142, it is determined whether or not to replace the 1-ner back. If it is necessary to replace it (determined at step A142M), the tonneau bag is replaced (step A146), and when the replacement is completed (step A146 and A147), the process proceeds to step A143. In step A143, it is determined whether the empty switch of the first developing device 203 is set to 0N10FF to determine whether or not there is no toner of the first color. If there is no first color toner (step A143), check whether the mode is the second color mode based on status 1 (step A148); if it is the first color mode and two-color printing mode (step A148) Step A144 at Step A150 (No), Complete replenishment of the first color toner to the first developing device 203 (Yes at Step A149)
Proceed to. Also, if it is the second color mode (step A14
8 portrait), step A149. Proceed to step Δ150 to Sugitsubu A144. In step A144, it is determined whether the empty switch of the second developing device 206 is set to 0N10FF to determine whether or not there is no second color toner. If there is no second color toner (step A144A fixed), check whether the status 1 is the first color mode or not.Step A15
1), if the mode is the second color mode and the two-color printing mode (step A151 negative), the second color toner supply to the second developing device 206 is completed (step A152 fM fixed, A153)
The process then proceeds to step 145. Also, if the first color is the first color (step A151 affirmative), step Δ152, Al
53 and proceeds to step 145.

In this way, if there is no abnormality in the toner status of the first developing device 203 and the second developing device 206, reception of commands from the host system 500 is permitted. (Step A145).

If there is a command specifying the first printing mode (step A154f6 fixed), the first color mode is set in status 1 (step A157), and if there is a command specifying the 20th print mode (step A155tl fixed) , the second color mode is set for status 1 (step A158).

Furthermore, if there is a command specifying the two-color printing mode (step A156), the two-color mode is set in status 1 (step A159).

Then, in the subsequent step A160, when the process of turning on IPRDY and turning on the IPREQ is executed, in the following step A161, a process of determining whether PRNT has been turned on is performed, and if it remains OFF, (No in step A161), the process returns to step A142, and if it is turned on (defaulting in step A161), the print request is turned off (step Δ162), and the process proceeds to the print processing after the routine shown in FIG.

In FIG. 17, step A163 to step A17
4, the processing after the warming-up processing routine is executed.

In the following step A177, it is checked based on status 1 whether the mode is the second color mode. If it is not the second color mode (No in step A177), the clutch of the first developing device 203 is turned on and the first developing device 203 is driven (step Δ178), and the process advances to step A179. If it is the second color mode (step A177 affirmative), step A178 is skipped and the process proceeds to step Δ179.

In step A179, it is checked based on status 1 whether the mode is the first color mode. If the mode is not the first color mode (No in step A179), the clutch of the second developing device 206 is turned on and the second developing device 206 is driven (step A1
80), proceed to step A181. If it is the second color mode, step A180 is skipped and the process proceeds to step A181.

In step A181, the bias table data regarding the toner color of the first developer 203 is read, and in the subsequent step A182, the read bias table data is set in the D/A converter 578, and in the subsequent step Δ1
In step A183, bias table data regarding the toner color of the second developing device 206 is read, and in the subsequent step A184, a process of setting the read bias table data in the D/Δ converter 584 is executed.

After the subsequent delay processing (step A185), potential control before first printing as shown in FIG. 22 is executed (
Step A186).

In the following step Δ187, it is checked based on status 1 whether the mode is the second color mode. 2nd color mode 1: dena f
If no (step A187 negative), the developing bias 409 of the first developer 203 is set to 0NL (step Δ188), and the process proceeds to step Δ190.

If the second color is one (step A187 affirmative), step Δ188 is skipped and the process proceeds to step A190, and the second charging potential control is performed as shown in FIG. 22 (step A18). .

In step A191 following the delay processing in step 190, it is checked based on status 1 whether the mode is the first color mode. If it is not the first color mode (No in step A191), the phenomenon bias 409 of the second developing device 206 is set to 0NL (
Step A192), then proceed to step A194. If it is the first color mode (step A191 affirmative), step A
Skip 192 and proceed to step △194, and
The first charging potential control is performed as shown in FIG. 22 (step Δ193).

In step A194, it is determined based on status 1 whether the paper feeding force is in the upper stage or in the lower stage. If it is determined that the paper feeding power is in the upper stage, the paper feed motor is driven in normal rotation to perform upper stage paper feeding (step A194). A195), step A
199, and after the delay processing in step A208, the paper feed motor is turned off (step A209). If it is determined that the paper is in the lower stage, step A195 is skipped, and after the delay processing (step A196>), the paper feed motor is reversed and paper is fed in the lower stage (step A197).
, when proceeding to step A199, in Jξ, step A208
After the delay processing, the paper feed motor is turned off (step A).
209).

In step 199, it is checked if it is the second color mode based on the status 1, and if it is not the second color mode (No in step A199), the process proceeds to step Δ202 after the delay processing in step A200. If it is the second color mode (Yes at step A199), the process proceeds to step A202 after the delay processing at step A201.

In step A202, beam detection ready is detected using the horizontal synchronization signal H3YNC, and the process proceeds to step A204. Note that if beam detection is not ready (No in step A202), beam detection failure processing is executed.

In step Δ204, as shown in FIGS. 20 and 21, the page top counter, page end counter,
A left margin counter, a right margin counter, and a two-beam scanning length correction value are set.

In the following step A205, a vSYNC request with status 1 is set, and the process waits for a VSYNC command (
Step A206), from the host system 500 to the VSY
When the NC command is sent, the VSYNC request is reset (step A207).

In the subsequent step A210 of FIG. 18, the top/bottom counters start counting and the image input starts, and then,
Based on status 1, it is confirmed whether or not it is the two-color printing mode (step A211>. Then, if it is the first color mode and the second color mode (step A211 negative), the process advances to step A213, and the two-color printing mode is selected. If there is (step A211 portrait), proceed to step A213 and at the same time
The first charging potential control as shown in FIG. 0 is repeated five times (step A212).

In the following step 213, the second
Check whether it is in color mode. If it is not the first color mode (No in step 213), the process proceeds to step 216 after the delay processing in step A214, and if it is the second color mode (
(Yes in step 213), the process proceeds to step 216 after the delay processing in step A215.

In step 216, when the registration motor is turned on and the total counter is turned on, the total counter is turned off after delay processing (A217) and the process proceeds to step A221. is turned off (step A220
).

In step A221, it is checked again whether the mode is the second color mode. If it is not the second color mode (step A22
1 negative), when the first page end is detected (step A222 affirmative), the first color image m-inclusion ends, etc.
11 E N D 1 is output as a pulse (step A2
23), proceed to step Δ224. In step Δ224, it is checked whether the mode is the first color mode.

If status 1 is the first color mode (step A22
4 (affirmative), when the first developing device 203 has the first color toner (step A231 negative), the second developing device 206 has the second color toner.
Even if there is no color toner (step A238 affirmative), the 19th
As shown in the figure, the print request IPREQ is turned on (step A248).

At this time, when there is no first color toner in the first developing device 203 (step A231 portrait) and there is also no second color toner in the second developing device 206 (step A232 affirmative), the print ready state is displayed as shown in FIG. IPRDY is turned off (step A252).

Also, even if the first color 1 to ner is not in the first current @ container 203 (
Step A231 t# fixed), there is second color toner in the second developing device 206 (Step A232 negative), and the first
If both the color and the second color are the same color, (Step A
233 u setting), as soon as the second color printing mode designation command is issued (step A234 portrait), the current bias 409 of the first developing device 203 and its clutch are turned OFF.
(Step Δ235), the charging potential control of the first charger 201 is stopped, and the first charger 201 is turned off (Step A236>), the second color mode of status 1 is set (Step A237), and printing is started. Request IPREQ is turned on (step A248).

On the other hand, when there is toner of the first color in the first developing device 203 (No in step A231) and there is toner of the second color in the second developing device 206 (No in step A238), a command for specifying the second color printing mode is issued. If there is (step A239
(Yes), the developing bias 409 of the first developing device 203 and its clutch are turned off (step A235), and the W1 electric potential control of the first charging device 201 is stopped.
01 is turned off (step A236), and the second color mode setting of status 1 is executed (step Δ237).
), the print request IPREQ is turned on (step A248>).

On the other hand, when it is determined in step A221 that the mode is the second color mode, and it is determined that the mode is not the first color mode in step A224, when the second page end is detected (step A
225 Portrait), 2nd color image writing is completed and IPEND
2 is output as a pulse (step A226>, step A
Proceed to 227.

If status 1 is the second color mode (step A22
7 (Yes), even if there is no second color 1-toner in the second developing device 206 (Yes in Step A240), the first developing device 203 has no
There is color toner (step A241 negative), and the first
If both the color and the second color are the same (step A242
(Yes), when a command specifying the first color printing mode is issued (Yes at Step A243), the developing bias 409 of the second developing device 206 and its clutch are turned off (Step 2/14), and the second charging device 204 After the charging control is stopped and the second charger 204 is set to 0 (step A245a>), the first color mode of status 1 is set (step A245b), and then the second color mode is set (step A245b). The print request IPREQ is turned on (step A248).

Also, in step A227, status 1 is the second
If the mode is other than the color mode, it is determined in step A228 whether the first color toner is out based on the status 5, and in step A229 it is determined based on the status 5 whether or not the second color toner is out. And step A228
．． If 1 to no error is found in A229, print ready + 1) RDY is turned off as shown in Figure @67 (step △252).

Also, if there are first and second color toners (step A
228 negative, 229 negative), the process proceeds to step A248, and at the same time, the second charging potential ai control as shown in FIG. 22 is performed twice (step A230).
In the routine from 1 to Δ248, by deleting 7111fli in step A232 and step 242, even if the toners in the first developing device 203 and the second developing device 206 are of a different color, continuous development can be performed by switching the developing device. is entered in line 4'.

In FIG. 19, after 9fiJI turns on the print request IPREQ in step A248, IPRNTO
fJI cutting process that holds N for 5 seconds (steps A249, A2
50) is executed and if IPRNT is turned ON (step A249 affirmative), the print request [PREQ is turned OFF (step A251), and it is determined whether the print mode has been changed (step A266).

If you have changed the print mode, go to step 266.
bulking), return to step Δ177, and step A177~
During step A194, check the status 1 and
The developing device 203 or the second developing device 206 is made ready for development.

If the print mode has not been changed, skip step A26.
6 negative), return to step A194, and step A177
The processing from step A193 to step A193 is omitted.

However, in any printing mode, the step Δ
Since the processes 142 to Δ174 are repeated without being performed, the recording operation continues without temporarily stopping the two-color LBP 199.

In contrast, when the judgment process of keeping IPRNT ON for 5 seconds (steps A249 and A250) is executed,
If 5 seconds have elapsed (Yes in step A250), after the stop processing in steps A253 to A265, the process returns to step A142 and enters a standby state for a command from the host system 500.

In addition, if the print ready I PRDY is OFF (step A252>, the print operation is not necessary, so
After the stop processing in steps A253 to A265, the process returns to step A142, and the host 1 enters a standby state with a command from the system 500.

FIGS. 20 and 21 show step △204 in FIG. 17.
3 is a flowchart showing the processing of FIG.

In the subroutines shown in FIGS. 20 and 21,
The process of coarsely adjusting and setting the top margin from step 8101 to step B107, the process of finely adjusting and setting the top margin from step 3114 to step 13119, and the process of finely adjusting the bottom margin from step 8120 to step B123. , step 8124
〜Step 8128 to coarsely adjust the left margin, step 8129 to step B131 to coarsely adjust the right margin, and step 813
2 to step 8136 to fine-adjust and set the write margin, and step 8137 to step B141 to 2.
The processing is roughly divided into beam scanning correction set processing, and the details thereof are as shown in the figure.

That is, in the process of setting the top margin coarse adjustment from step 8101 to step 107, after reading the first color top margin table data D1 (step B101), the top margin rough adjustment switch is read (step 131).
02>, the top margin coarse adjustment table data D2 corresponding to the switch is also read (step B103).

In the subsequent step B104, the top margin coarse adjustment table data D2 is added to or subtracted from the value of the first color top margin table data D1 to obtain a calculation result D3.

In the following step B105, if status 1 is not the two-color mode (step B105 negative), the calculation result D3 is used as the first color mode.
Set the page top counter 859 (step B
106), the routine proceeds to steps 8108 to B113 for rough adjustment of the bottom margin. Also, if status 1 is two-color mode (step 8105fJ fixed)
, set the fight result D3 in the second page top counter 861 (step B107), and also in step 810.
Proceed to the routine from 8 to B113.

After reading the bottom margin table data D4 of the specified paper size in step 8108, in the following step B109, the first color top margin table data D1 is added to the bottom margin table data D4 to obtain a calculation result D5.

In the subsequent step B110, the margin rough adjustment table data D2 is added to the value of the calculation result D5 to obtain the 'tJ calculation result D6.

In the following step B111, if step 1 is not the second color mode (step B111 negative), the calculation result D6 is set to the first color mode.
Set the page end counter 860 (step B
113), the process advances to steps 8114 to B119, a routine for finely adjusting and setting the top margin. Further, if step 1 is the second color mode (step B111 affirmative),
The calculation result D6 is set in the second page end counter 862 (step B112>, and also in step 8114).
~ Proceed to routine B19.

When the second color top margin table data D7 is read in step B114, the top margin image adjustment switch is sold in the subsequent step B115, and the subsequent step 81
In step 16, the top margin fine adjustment table data D8 corresponding to the switch is read.

In the following step 8117, the margin rough adjustment table data D2 is added to the value of the second color top margin table data D7.
and the fine adjustment data D8 are added or subtracted to obtain a calculation result D9.

If the status 1 is not the two-color mode in the following step 8118 (step 8118 negative), steps 8120~
Proceed to the bottom margin fine adjustment set routine of 8123. Furthermore, if status 1 is the two-color mode (step 8118), set t7W;'AD9 to the second page top counter 861 (step 8119).
, similarly proceeds to the routine of steps 8120 to B123.

In step B120, the bottom margin table data D4
Add the second color top margin table data D7 to C
After obtaining the calculated nM beam D10, in the subsequent step B121, the margin rough adjustment table D8 is added or subtracted from the value of the calculated result D10 to obtain the calculated result 011.

If the status 1 is not the two-color mode in the subsequent step B122 (step B122 negative), steps 8124~
The process advances to the left margin coarse adjustment set routine of 8128. If the status 1 is 2-color 7-card (Yes at step B122), the calculation result 011 is set in the second page end counter (step B123), and the routine similarly proceeds to steps 8124-8128.

In step B124, left margin table data D1
2 is read, the left margin coarse adjustment switch is read in the subsequent step B125, and the left margin coarse adjustment table data 1]13 corresponding to the switch is read in the subsequent step 8126.

In the following step B127, the rough margin adjustment table D13 is added or subtracted from the value of the left margin table data D12 to obtain the calculation result D14.

In the following step 8128, the calculation result D14 is set in the left margin counter 863, and steps 8129 to
The process advances to B131, the light margin coarse adjustment set routine.

In step B129, the light margin table data D15 of the designated paper size is read, and in the subsequent step B130, the margin rough adjustment table data D13 is added or subtracted from (0) of the light margin table data D15 to obtain the calculation result D16.

In the following step B131, when the calculation result D16 is hit to the write margin counter 864, steps 8132 to
The program proceeds to a routine for finely adjusting and setting the write margin of 8136.

In step B132, the left margin Wi adjustment switch is read, and in the subsequent step B133, the left margin fine adjustment table data D17 corresponding to the switch is set to 5, and in the subsequent step B134, the value of the table data D17 is set in the n bit ludge 851.

In the subsequent step B135, the print area changeover switch is read, and in the subsequent step 13136, the I10 boat 830 is set according to the print area changeover switch, and then in step 8137.
-Proceed to the two-beam scanning length correction routine at B141.

In step B137, the 2-beam scanning length correction switch is read, and in the subsequent step 8138, the scanning length correction table data D18 corresponding to the switches 1 and 6 is set to -, and in the subsequent step 8139, this table data D188 is set to the n-bit latch 847. do.

In the subsequent Stella 7' B140, the dot clock changeover switch is read, and in accordance with this dot clock changeover switch, in the subsequent step B141, the I/O/I knee 1.83 is read.
0 is set, and the process of step Δ204 shown in FIG. 17 ends.

FIG. 22 is a 70-chip chart showing potential control during warm-up and potential control ylI before first printing.

Potential control during warming up is performed at the first charging time al
The control output value CHD+ is read from the table data (step C101), and the read value is set in the D/A converter 576 (step C102). In addition, the value Cl1D2 of the second belt core initial control output is read from the table data (step C103), and the read value is converted to D/
'Set in the A converter 582 (step C104
).

When the first charger 201 is turned on in the subsequent step ClO3, the first charging potential control is executed as shown in FIGS. 23 and 24 (step 0106). The subsequent delay processing (
Step C107) In step 0108, the second
When the charger 204 is turned on, second charging potential control is executed as shown in FIGS. 23 and 24 (step C
109).

Then, step C110) increments the potential control number n.
, until this potential control number of times 0 reaches 3, step 0105 to step C111) are repeated until 3 times? 1, the first charger 201 and the second charger 204 are turned off.
F (step C112), and this warming-up potential ALL 111 ends.

If the status 1 is not the second color mode (step D101), the potential control of the tour strip moe is set to the first color mode.
The charger 201 is turned on (step 0102), and the seventh
As shown in FIG. 1 and FIG. 72, the first charging potential control is executed (step D103), and if only the first color mode is present (step D104), the potential it before first printing and the end of the II control are executed. Become.

Moreover, if it is two-color mode (step D104 negative),
After the delay process (step D105), the second charger 204
is turned on, and the second charging potential control is executed as shown in FIGS. 71 and 72 (step D 107 ), and the potential υ+111 before the first printing ends.

Also, status 1 is the second in step D101 for the first time in la.
If it is color mode, only the second color mode is executed, so
The second charger 204 is turned on (step D106),
As shown in FIGS. 23 and 24, the second charging potential control is executed (step D107), and the potential control before first printing is completed.

FIGS. 23 and 24 are flowcharts showing details of the charging potential control Ill process.

In the subroutines shown in FIGS. 23 and 24,
First, the A/D converter 593 detects the drum temperature detector 570.
is received (step F101), and the photoreceptor 200
temperature measurement is performed (step E102). Then, either the first charging potential Luli control or the second charging potential Hil+ control is selected (step E103), and the ROM 503
Based on the data table, in the case of the first charging potential control, each process from step 0105 to step E109 is executed f1, and in the case of the second charging potential aIIB,
Each process from step 113 to step E118 is executed.

Then, in step E110 and step E119,
The first target surface potential data (VO8I) and the second target surface potential data (VO32) are each corrected to correspond to the actual temperature of the photoreceptor 200, and each of the corresponding correction data vosi- and VO82- is reduced by 1q. .

In the following steps E111 and E120, in order to store the values obtained in steps E104 to E110 and the values obtained in steps E113 to E119 in a common register, the same calculations as in steps E111 and E120 are performed. Processing is executed.

In the following steps E112 and E121, A
/D converter 593 sets the first potential regulator 202 and second potential regulator 205, respectively.

Next, the first WI charging potential control and the second charging potential shift 11υ
Regardless of O, each process from step E122 onwards is executed.

First, 1. A delay process is executed for a time corresponding to the travel distance between the second chargers 201, 204 and the first and second chargers 202 and 205, and The surface potential S is measured by the second surface sensors 202 and 205 (
Steps E122°E123).

From the following steps onward, step 111 and step E
Processing is performed based on each data shown at 120.

That is, in step E124, the read value is Vos+VoM A
Self-diagnose whether it is X or more, F or not. If this is the case (Yes in step 124), potential control error processing is executed. (
Step E125). If it is less than (step E124
(No), proceed to step E126.

In step E126, it is determined whether the read value is within the target value and the control range of the error table according to the arithmetic expression VS=VO3+VOZ.

If not (step E126 negative), step by step check how much the voltage is deviated from the target by, for example, 200V, 100V, or 50V (steps E127 and E128).
．． E129), a process of setting the control amount to the same size, twice, four times, and six times as ΔX or ΔX2) is executed (step E130.E131.E132.E).
133).

After this setting, the process proceeds to step E134, in which the charging output is set, and in the subsequent step E135, it is checked whether the charging output is larger than the maximum value, and in the subsequent step E13.
6, it is checked whether the charging output is smaller than the minimum value, and if it is too large or too small (step E135 affirmative), the potential i
d control error processing is executed (step E137).

If the charging output is within the control range (step E135 negative, step E136 negative), step E1
38, it is determined whether the actual potential control target is the first charger 201 or the second charger 204.

If this determination result is the first Wl electric appliance 201, CHo
T + = C1-11') After setting T (step E
139), the process of setting CHI)T I in the D/A converter 576 is executed, and the process advances to step E145.

Also, if this determination result is the second charger 204, the CHD
After setting T 2 = cl-1o T (step E141), set Cf-1 electric knife 1 to D/
The process of setting the A converter 582 is executed, and the process advances to step E145.

In step E145, the number of times of charging potential control is incremented, and the routine proceeds to step E146 and subsequent steps in FIG.

That is, if the potential control is performed before the first print (step E146 is determined), the potential control number m is 3 (step [151 affirmative)], and the non-convergence due to potential control ends. Return to

In addition, for potential control during warming up (step E147, step E147), the potential control number m is 10 times (step 2151F4, step 2151), Ti position control error processing is carried out (step E153), and the IIc Return to step E122 up to 9 times.

J: If status 1 is not 2-color mode (step E148 negative), the process returns to step E122, but if status 1 is 2-color mode (step E148 t)
1) determine whether the potential control pair is the first charger 201 or the second charger 204;
If it is 01, the potential control ends when the potential control is performed five times (1j-) (step 150 +ij constant), and if it is the second charger 2071, the potential control ends when the potential control 121I is performed twice (step 154 portrait). This is the end of the electric potential.

As described above, in one embodiment of the present invention, as explained in particular with reference to FIG. The video clock signals (IVCLKl, IVCLK2) are output from the host system 500 to 22 clock signals based on the video clock signals.
Video data signal (IOAT 1, IVl) to interface 1-- bus circuit 519 of LBP 199
) There is no difference in the start timing of sending video data signals from the host system 500. Therefore, it is possible to accurately determine the recording start position of the paper in two colors L8P199.

[Effect of the Invention 1 As explained above, the image forming Jli device 9 to which the present invention is applied, the mark [ii+! The system configuration is such that a video clock signal synchronized with the paper recording start position is output from the host side, and a video data signal is sent from the host side to the printing side based on this video clock signal, so it is possible to start recording the paper on the printing side. The position is accurate.

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing an embodiment of an image forming apparatus to which the present invention is applied, and FIG.
Color LBP system (block diagram showing 111 configuration, 3rd
The figure shows the contents of the ROM data table, Figure 4 shows the details of the interface signal between the interface circuit and the host system, Figure 5 shows the relationship between the interface signal and the data 1 position, and Figure 6 is 2 colors L8
Detailed explanation of commands used in P, Figure 7 is 2-color LB
Detailed explanation diagram of each status used in P, Figure 8 is a block diagram showing details of the laser modulation circuit and semiconductor laser, and Figure 9 is a circuit showing the five circuits of the beam detection circuit and beam detector 111. Figure 10 shows the relationship between the scanning range of the laser beam once, the beam detection position, and the f-data old pick position, and Figure 11 shows the positional relationship of the data 1 included position of the entire sheet. Figure 12 is a circuit diagram showing the details of the print data writing control circuit, Figure 13 is a timing chart of the Lll fil signal including 1 print data in two-color printing mode, and Figure 14 is a diagram showing data for one line. Timing charts of write control signals, Figures 15 to 19 are for two-color LBP
Flowchart showing body 'E) + t'i: 2nd
0 and 21 show subroutines for setting the page top counter, page end counter, left margin counter, right margin counter, and two-beam scanning length correction value. FIG. 23 and FIG. 24 are flowcharts showing a subroutine for controlling the charging potential before first printing, and FIG. 25 is an explanatory diagram of a conventional image forming apparatus. 199...Two-color LBP 500...Host system 519...Interface circuit

Claims (1)

[Claims] It consists of a printing side and a host side that sends various data signals to the printing side.The printing side outputs a video clock signal synchronized with the recording start position of the paper, and the host side An image forming apparatus characterized in that the image forming apparatus starts sending a video data signal to the printing side from the start.