JP2000313140A - Imaging apparatus, imaging method, and recording medium storing imaging control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrophotographic imaging apparatus in which the reliability is enhanced while simplifying the structure by realizing conventionally independent sync signals in main scanning direction and sub-scanning direction through a single signal line. SOLUTION: Upon detecting arrival of a recording sheet at a resist roller sensor 132, an engine controller 126 resets and starts a page timer 403 in order to measure a page of image area and delivers an optical beam detection signal, as a sync signal in main scanning direction and sub-scanning direction, to a video controller 127. Upon elapsing time t1 after receiving the sync signal, the video controller 127 begins to output a VDO signal as a page of image data. An engine controller 126 interrupts delivery of the sync signal when a page timer 403 reaches a predetermined time. An optical beam detection signal counter may be employed in place of the page timer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus and an image forming method for performing optical writing using a light beam, and a storage medium storing an image forming control program.

[0002]

2. Description of the Related Art A video controller of this type of image forming apparatus uses a synchronization signal indicating the start of main scanning and a synchronization signal indicating the leading edge of a recording sheet (recording medium) sent from a printer engine. An image is formed by generating a scanning synchronization signal and a sub-scanning synchronization signal and sending an image signal to a printer engine based on both synchronization signals.

[0003]

However, in the above-described conventional example, as shown in FIG. 11, at the start of each page to be printed, a synchronization signal (sub-scan synchronization signal) in the sub-scanning direction is started. Since it is used as a signal, it is necessary to secure an individual signal line only for notifying the start of each page. As a result, there is a problem to be solved such that the signal line becomes complicated, and furthermore, the reliability is reduced, for example, the failure is hardly found.

The present invention has been made in view of the above points, and has as its object to generate a synchronization signal for synchronizing in the main scanning direction and the sub-scanning direction using a light beam detection signal. An image forming apparatus and an image forming method capable of realizing a main scanning direction synchronization signal and a sub-scanning direction synchronization signal, which are conventionally separate, with a single signal line, simplifying the apparatus and improving reliability, Another object of the present invention is to provide a storage medium storing an image formation control program.

[0005]

According to a first aspect of the present invention, there is provided an image forming apparatus for forming an image by scanning a plurality of light beams on a photosensitive member. Scanning means for scanning the photoreceptor and a recording area surrounding the photoreceptor; light beam detection means for generating a light beam detection signal by detecting a light beam at a predetermined position corresponding to the outside of the recording area; Recording medium detecting means for detecting the leading and trailing ends of the recording medium, and time measuring means for measuring time for measuring an image area for one page based on the detection result obtained by the recording medium detecting means And synchronizing the light beam detection signal in the main scanning direction and the sub-scanning direction based on the detection result obtained by the recording medium detection unit and the result measured by the time measurement unit. Characterized by comprising a synchronization signal output means for outputting as because of the synchronization signal.

According to another aspect of the present invention, there is provided an image forming apparatus for forming an image by scanning a plurality of light beams on a photosensitive member. Scanning means for scanning outside the recording area; light beam detecting means for generating a light beam detection signal by detecting a light beam at a predetermined position corresponding to the outside of the recording area; Recording medium detection means for detecting an end; counting means for counting the light beam detection signal to measure an image area for one page based on a detection result obtained by the recording medium detection means; Based on the detection result obtained by the recording medium detection unit and the result measured by the counting unit, the light beam detection signal is changed in the main scanning direction and the sub-scanning direction. Characterized by comprising a synchronization signal output means for outputting a synchronizing signal for synchronization.

Here, it is possible to have an image signal output means for outputting an image signal for modulating the light beam based on the synchronization signal.

Further, the image signal output means includes a pulse interval measuring means for measuring a pulse interval of the synchronization signal, and one based on a result measured by the pulse interval measuring means.
An image area end determining unit that determines that the image area of the page has ended can be provided.

The image signal output means includes counting means for counting pulses of the synchronization signal, and image area determination means for determining an image area for one page based on the result counted by the counting means. It can be characterized by having.

The image signal output means includes an integration means for integrating the synchronization signal, and an image area determination for determining that one image area has been completed based on the result measured by the integration means. Means.

According to a seventh aspect of the present invention, there is provided an image forming method for forming an image by scanning a plurality of light beams on a photosensitive member. A scanning step of scanning outside the recording area, a light beam detection step of generating a light beam detection signal by detecting a light beam at a predetermined position corresponding to the outside of the recording area, and a leading end and a trailing end of the conveyed recording medium. A recording medium detection step of detecting an end;
A time measuring step of measuring a time for measuring an image area for one page based on the detection result obtained in the recording medium detection step, and a detection result obtained in the recording medium detection step and the time A synchronizing signal output step of outputting the light beam detection signal as a synchronizing signal for synchronizing the main scanning direction and the sub-scanning direction based on a result measured in the measuring step.

According to another aspect of the present invention, there is provided an image forming method for forming an image by scanning a plurality of light beams on a photosensitive member. A scanning step of scanning outside the recording area, a light beam detection step of generating a light beam detection signal by detecting a light beam at a predetermined position corresponding to the outside of the recording area, and a leading end and a trailing end of the conveyed recording medium. A recording medium detection step of detecting an end;
A counting step of counting the light beam detection signal in order to measure an image area for one page based on the detection result obtained in the recording medium detection step, and a detection result obtained in the recording medium detection step And a synchronizing signal output step of outputting the light beam detection signal as a synchronizing signal for synchronizing the main scanning direction and the sub-scanning direction based on the result measured by the counting step.

In order to achieve the above object, the invention according to claim 13 is a scanning means for scanning a photosensitive member and a surrounding area outside a recording area with a light beam, and detecting the light beam at a predetermined position corresponding to outside the recording area. Scanning means for generating a light beam detection signal, and a recording medium detecting means for detecting a leading end and a trailing end of a conveyed recording medium, and scanning a plurality of light beams on the photosensitive member. A control program for controlling the image forming apparatus for forming an image by a computer by the computer program, the control program instructing the computer to detect a detection result obtained by the recording medium detection unit. Start time measurement to measure image area for one page based on
Outputting the light beam detection signal as a synchronization signal for synchronizing the main scanning direction and the sub-scanning direction based on a detection result obtained by the recording medium detection unit and a result measured by the time measurement. It is characterized by.

In order to achieve the above object, the invention according to claim 14 is a scanning means for scanning a photosensitive member and a surrounding area outside a recording area with a light beam, and detecting the light beam at a predetermined position corresponding to outside the recording area. Scanning means for generating a light beam detection signal, and a recording medium detecting means for detecting a leading end and a trailing end of a conveyed recording medium, and scanning a plurality of light beams on the photosensitive member. A storage medium storing a control program for controlling an image forming apparatus for forming an image by a computer by the computer, the control program instructing the computer to detect a detection result obtained by the recording medium detection unit. Based on 1
The light beam detection signal is counted in order to measure the image area of the page, and the light beam detection signal is counted in the main scanning direction and the sub scanning direction based on the detection result obtained by the recording medium detection means and the count result. It is characterized in that it is output as a synchronization signal for synchronizing in the scanning direction.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 shows a schematic configuration of, for example, a laser beam printer as an image forming apparatus using an electrophotographic process suitable for applying the present invention.

The laser beam printer main body 101 (hereinafter, referred to as a laser beam printer main body)
The main body 101) has a cassette 102 for storing recording paper (recording medium) S. In response to the force set 102, a cassette presence / absence sensor 103 for detecting the presence or absence of the recording paper S in the cassette 102, and recording of the cassette 102 A cassette size sensor 104 (comprising a plurality of microswitches) for detecting the size of the paper S;
And the like are provided.

Downstream of the paper feed roller 105, a registration roller pair 106 for synchronously transporting the recording paper S is provided. A top sensor 132 for detecting the state of conveyance to the registration roller pair 106 is provided on the registration roller pair 106.
The image forming unit 108 that forms a toner image on the recording paper S based on the laser beam from the laser scanner unit 107 is provided downstream of the image forming unit 108.

A fixing unit 109 for thermally fixing the toner image formed on the recording paper S is provided downstream of the image forming unit 108, and a conveyance state of the sheet discharging unit is detected downstream of the fixing unit 109. A paper ejection sensor 110, a paper ejection roller 111 for ejecting the recording paper S, and a loading tray 112 for loading the recording paper S on which recording has been completed are provided.

The laser scanner unit 107 includes a laser unit 113 for emitting a laser beam modulated based on an image signal (image signal / VDO) sent from a video controller 127 to be described later.
A polygon motor and a polygon mirror 114 for scanning the laser beam from the
The imaging lens 115, the folding mirror 116, the laser light detection sensor 133 for synchronizing the scanning of the laser light, the BD mirror 134, and the like are arranged in the arrangement shown in FIG. The laser light detection sensor 133 is disposed outside the image recording area indicated by a broken line as shown in FIG. 2 and detects reflected light from a BD (laser light detection) mirror 134 to generate a signal / BD.
Signal is being output.

The image forming section 108 includes a photosensitive drum 117, a primary charging roller 119, a developing device 120, a transfer charging roller 121, a cleaner 122, and the like, which are necessary for a known electrophotographic process.

The fixing device 109 comprises a fixing film 109a, a pressure roller 109b, a ceramic heater 109c provided inside the fixing film, a thermistor 109d for detecting the surface temperature of the ceramic heater, and the like.

The main motor 123 applies a driving force to the sheet feeding roller 105 via a sheet feeding roller clutch 124 and a driving force to the registration roller pair 106 via a registration roller clutch 125, respectively. Driving force is also applied to each unit of the forming unit 108, the fixing device 109, and the paper discharge roller 111.

Reference numeral 126 denotes an engine controller, which includes a laser scanner unit 107, an image forming unit 108, and the fixing unit 10.
9 for controlling the electrophotographic process and the main body 10
1 is carried out.

The video controller 127 is connected to an external device 131 such as a personal computer by a general-purpose interface (Centronics, RS232C, etc.) 130, and develops image information sent from the general-purpose interface 130 into bit data. The bit data is used as a / VDO signal as an engine controller 126
Sent to

A signal line 128 connecting the engine controller 126 and the video controller 127 is composed of a command / status signal line, a clock signal line, a / VDO signal line, a synchronization signal line, etc. between the two controllers.

Upon receiving a print request from the video controller 127, the engine controller 126 starts driving the main motor 123 and the polygon motor 114. By driving the main motor 123, the photosensitive drum 117, the fixing film 109a of the fixing device 109,
The pressure roller I09b and the discharge roller 111 start rotating. After this, the engine controller 126
While starting the light quantity control of the laser unit 113,
High-pressure driving of the primary charging roller 119, the developing device 120, and the transfer charging roller 121 is sequentially performed.

FIG. 3 shows the output timing of image data in the laser printer of FIG. FIG. 4 shows a waveform example of the synchronization signal of FIG. The block diagram of FIG. 5 shows the flow of processing of the engine controller 126 that generates a synchronization signal from the detection signal from the laser light detection sensor 133 of FIG. 1 and the video controller 127 that operates based on this synchronization signal. The flowchart of FIG. 6 shows a schematic flow of the printing operation in the laser printer of FIG. Next, the operation of the embodiment of the present invention will be described with reference to FIGS.

First, in step S502 of FIG. 6 (where S represents a step), when a print operation start command is received from an external device 131 such as a personal computer, the CPU (central processing unit) 402 of the engine controller 126 prints. The operation starts (S503).
When the CPU 402 of the engine controller 126 detects that the rotation of the polygon motor 114 has reached a steady state from the pulse interval of the / BD signal sent from the laser light detection sensor 133, the CPU 402 turns on the paper feed roller clutch 124 and turns on the paper feed roller. By driving 105, the recording paper S in the paper feed cassette 102 is fed toward the registration roller pair 106.

Thereafter, when the CPU 402 detects that the recording paper S has reached the registration roller sensor 132, the CPU 402
In order to measure the image area of one page, in step S504, the page timer 403 is reset and started, and the / BD signal is output to the video controller 127 as a synchronization signal as shown in FIGS.
At the same time, the feed roller clutch 124 is turned off, and the driving of the feed roller 105 is stopped.

At this time, the video controller 127 has finished developing the image information from the external device 131 into a dot image, and has completed the preparation for outputting the / VDO signal. Image signal control unit 4 inside video controller 127
06 starts output of the / VDO signal as image data for one page after the time t1 from the reception of the synchronization signal from the engine controller 126.

On the other hand, when the output of the synchronizing signal is started, the engine controller 126
5 is turned on, and the registration roller pair 106 is driven. The registration roller pair 106 is driven until the trailing edge of the recording paper S passes through the registration roller 106. During this time, the engine controller 126 responds to the / VDO signal from the video controller 127 to
13 is driven. The laser light emitted from the laser unit 113 is transmitted to the polygon mirror 11 of the laser scanner 107.
4 is converted into a linear scan by rotation of the photosensitive drum 11 by the imaging lens 115 and the return mirror 116.
7 is illuminated. Hereinafter, by repeating the same operation, a latent image for one page is formed on the photosensitive drum 117.

When the page timer 403 reaches a predetermined time after the completion of the latent image formation, in step S505,
The engine controller 126 determines that the output of the image data / VDO for one page is completed, and stops outputting the synchronization signal to the video controller 127.

The end time of the page timer 403 may have some allowance so that the synchronization signal does not end during the output of the image data / VDO. In the above example, the page timer 403 is started after the registration roller sensor 132 detects the leading end of the recording paper S, whereas the registration roller sensor 132 is
The page timer 403 is started after detecting the trailing edge of
The end of one page may be determined when a predetermined time has passed after passing the trailing edge. If the output of one page of image data does not end and remains in the video controller 127 even though the synchronization signal is stopped, it is determined that there is an abnormality.

The latent image formed on the photosensitive drum 117 is
The toner image is developed by the developing device 120, and then the toner image is transferred to the recording paper S by the transfer charging roller 121. When the transfer is completed, the recording paper S is conveyed to the fixing device 109,
After the toner image is fixed on the recording paper S, the discharge rollers 111
Is discharged outside the machine. When printing the next page (S506), the process returns to S504, and the CPU 402 of the engine controller 126 outputs a synchronization signal again to perform the same control as the printing of the first page.

In the case of performing continuous printing, it is necessary for the video controller 127 to distinguish between the first page and the second page synchronization signals. Video controller 12
7, a pulse interval measuring unit 405 comprising a known timer
In, always measures the pulse interval of the synchronization signal,
1 when a time interval of a predetermined time or more occurs in the synchronization signal.
It is determined that the synchronization signal for the page has ended. in this case,
For the pulse interval during the output of the synchronization signal,
It is assumed that the pulse interval between the pages is at least twice as long.

As described above, in this embodiment, the engine controller 126 generates a synchronization signal for synchronizing the main scanning direction and the sub-scanning direction using the light beam detection signal (/ BD signal). Therefore, the synchronization signal in the main scanning direction and the synchronization signal in the sub-scanning direction, which have been conventionally separated, can be realized by one signal line, so that the device can be simplified and the reliability can be improved.

The present embodiment can be applied to both a single laser using a single laser beam and a multi-laser using a plurality of laser beams.

(Second Embodiment) In a second embodiment of the present invention, a counter is used instead of the page timer 403 to determine the image area and the non-image area for one page. .

FIG. 7 is a block diagram of the second embodiment of the present invention.
The flow of processing of an engine controller 126 that generates a synchronization signal from a BD signal and a video controller 127 that operates based on the synchronization signal will be described. Here, reference numeral 601 denotes a counter in the engine controller 126, and 602 denotes a pulse counter in the video controller 127. The flowchart of FIG. 8 shows a schematic flow of the printing operation of the laser printer of FIG. 1 in the present embodiment.

Next, the operation of the second embodiment of the present invention will be described with reference to FIGS. 1, 3, 4, 7, and 8. The description of the main operation is as described in the above-described first embodiment of the present invention, and will not be repeated.

First, in S702 of FIG. 8, when a print operation start command is received from the external device 131 such as a personal computer, the CP of the engine controller 126 is started.
U402 starts the printing operation (S703). Upon detecting that the recording sheet S has reached the registration roller sensor 132, the CPU 402 of the engine controller 126 resets a counter 601 for counting the number of pulses of the / BD signal in S704 in order to detect an image area of one page. And starts, and outputs a synchronization signal to the video controller 127 as shown in FIG.

Also in the case of multi-laser driving using a plurality of laser beams, a single synchronization signal is sent from the engine controller 126 to the video controller 127. In this case, the synchronization signal includes pulses as many as the number of laser beams to be turned on per main scanning line. FIG. 4 is a diagram showing a synchronization signal sent to the video controller 127 when two laser beams are used. In this case, two pulses are generated per line. If the number of laser beams to be turned on per main scanning line is 4, the synchronizing signal is generated every four pulses per line.

Accordingly, C of the engine controller 126
The PU 402 needs to make a predetermined count number indicating the number of / BD pulses for one page correspond to the number of laser lights to be turned on in advance. For example, if the number of laser beams used is L
Assuming that n and the number of lines are n, the number of / BD counts for one page counted by the counter 601 is Ln × n. Therefore, in S705, when the / BD count number of the counter 601 has reached Ln × n in S705, the CPU 402 regards that the output of the image signal for one page has ended, and
Stop the output of the synchronization signal. The / VDO signal has the same number of signal lines as the number of light beams, and drives the light beams independently. In the case of continuous printing, step S704
And the above operation is repeated (S706).

When performing continuous printing, the video controller 127 also needs to distinguish between the first page and the second page synchronization signals. In order to distinguish the synchronization signal of the first page from the synchronization signal of the second page, the synchronization signal for one page is counted by the pulse counter 602 on the video controller 127 side. At this time, similarly to the above case on the engine controller 126 side, when a plurality of synchronizing signal pulses are output per scanning line by a plurality of beams, it is dealt with by changing a predetermined count number.

As described above, in this embodiment, / B
By using a counter that counts the D signal, even in a multi-laser driving method using a plurality of laser beams,
As in the first embodiment, the synchronization signal can be realized by one signal line.

In some cases, even when a plurality of beams are provided, the control may be performed by using only one pulse per scan as a synchronization signal.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. 1, FIG. 4, FIG. 9, and FIG. The description of the main operation is as described in the above-described first embodiment of the present invention, and will not be repeated.

In this embodiment, the first page and the second page of the video controller 127 are mainly used during continuous printing.
A method for distinguishing the synchronization signal of the page will be described.

FIG. 4 shows a synchronization signal sent to the video controller 127 when two laser beams are used. As shown in FIG. 4, when two or more laser beams are used,
Naturally, the number of synchronization signal pulses per line in the main scanning direction is plural. The CP of the video controller 127 shown in FIG.
The U (or integration circuit) 801 samples the synchronization signal at a cycle shorter than the pulse width of the synchronization signal, and the result is obtained at a cycle of one or more lines in the main scanning direction of the synchronization signal, for example, at a cycle of two lines. Aggregation is performed, and the boundary between the first page and the second page is determined based on the aggregation result. That is, CPU
If the count result obtained by sampling at 801 is equal to or less than a predetermined value, the CPU 801 determines that the synchronization pulse has ended based on the count result and regards the end of one page.

In the present embodiment, the processing on software is mainly described, but the same processing may be realized on hardware. In this case as well, a configuration as shown in FIG. 9 is adopted, and a synchronizing signal is input to the integrating circuit 801 to output an integrated waveform as shown in the waveform diagram of FIG. The integration signal is input to the image signal processing unit 406 to control the / VDO signal at the time of continuous printing, as in FIG.

(Other Embodiments) Even if the present invention is applied to a system constituted by a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus comprising one device (For example, a copying machine, a facsimile machine, etc.).

Another object of the present invention is to supply a storage medium (recording medium) storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and a computer of the system or apparatus. Needless to say, the present invention is also achieved when the CPU (or the CPU or the MPU) reads and executes the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As storage media for recording the program code and variable data such as tables, for example, a floppy disk (FD), hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, A nonvolatile memory card (IC memory card), a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. It goes without saying that an operating system) may perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

[0057]

As described above, according to the present invention,
The light beam scans the photoconductor and the surrounding area outside the recording area, and detects the light beam at a predetermined position corresponding to the outside of the recording area to generate a light beam detection signal. In an electrophotographic image forming apparatus having means for detecting edges, a synchronization signal for synchronizing the main scanning direction and the sub-scanning direction is generated using a light beam detection signal. The main scanning direction synchronizing signal and the sub-scanning direction synchronizing signal can be realized by one signal line, so that the device can be simplified and the reliability can be improved.

Further, according to the present invention, a page timer is used to determine the image area and the non-image area for one page.
Alternatively, by using a counter, a synchronization signal can be realized with one signal line even in the case of a multi-laser laser driving method using a plurality of laser beams.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view schematically showing a sectional configuration of an image forming apparatus suitable for the present invention.

FIG. 2 is a plan view showing a detailed arrangement of a laser beam scanning system of the image forming apparatus of FIG. 1;

FIG. 3 is a timing chart showing signal output timings according to the first embodiment of the present invention.

FIG. 4 is a waveform chart showing an example of a signal waveform of a synchronization signal in the first, second, and third embodiments of the present invention.

FIG. 5 is a block diagram illustrating a configuration of a signal processing system according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating a processing flow according to the first embodiment of the present invention.

FIG. 7 is a block diagram illustrating a configuration of a signal processing system according to a second embodiment of the present invention.

FIG. 8 is a flowchart illustrating a flow of processing according to a second embodiment of the present invention.

FIG. 9 is a block diagram illustrating a configuration of a signal processing system according to a third embodiment of the present invention.

FIG. 10 is a timing chart showing signal waveforms and output timings according to a third embodiment of the present invention.

FIG. 11 is a timing chart showing signal waveforms and output timings in a conventional example.

[Explanation of symbols]

 Reference Signs List 101 Image forming apparatus 102 Cassette 106 Registration roller pair 107 Laser scanner unit 109 Fixing unit 114 Scanner motor driver 117 Photosensitive drum 126 Engine controller 127 Video controller 131 External device such as personal computer 132 Registration roller sensor 133 Laser light detection sensor 402 CPU 403 page Timer 404 AND (logical product) gate 405 Pulse interval measurement unit 406 Image signal control unit 601 Counter 602 Pulse counter 801 CPU (or integration circuit) S Recording paper (recording medium)

Claims (18)

[Claims] 1. An image forming apparatus for forming an image by scanning a plurality of light beams on a photosensitive member, wherein: the scanning unit scans the photosensitive member and a recording area around the photosensitive member with the light beam; A light beam detecting means for generating a light beam detection signal by detecting a light beam at a predetermined position outside the area; a recording medium detecting means for detecting a leading end and a trailing end of a conveyed recording medium; 1 based on the detection result obtained by the recording medium detection means.
Time measuring means for measuring time to measure an image area for a page; and the light beam detection signal based on a detection result obtained by the recording medium detecting means and a result measured by the time measuring means. And a synchronizing signal output means for outputting a synchronizing signal for synchronizing in the main scanning direction and the sub-scanning direction. 2. An image forming apparatus for forming an image by scanning a plurality of light beams on a photosensitive member, wherein the scanning unit scans the photosensitive member and a recording area around the photosensitive member with the light beam; A light beam detecting means for generating a light beam detection signal by detecting a light beam at a predetermined position outside the area; a recording medium detecting means for detecting a leading end and a trailing end of a conveyed recording medium; Counting means for counting the light beam detection signal in order to measure an image area for one page based on the detection result obtained by the recording medium detection means; and detection result obtained by the recording medium detection means. The light beam detection signal is output as a synchronization signal for synchronizing the main scanning direction and the sub-scanning direction based on the result measured by the counting means. An image forming apparatus characterized by comprising a synchronization signal output means. 3. The image forming apparatus according to claim 1, further comprising an image signal output unit that outputs an image signal for modulating the light beam based on the synchronization signal. 4. An image signal output means, comprising: a pulse interval measuring means for measuring a pulse interval of the synchronization signal; and an image area for one page based on a result measured by the pulse interval measuring means. The image forming apparatus according to claim 3, further comprising: an image area end determining unit that determines whether the image forming operation has ended. 5. The image signal output unit includes: a counting unit that counts pulses of the synchronization signal; and 1 based on a result counted by the counting unit.
The image forming apparatus according to claim 3, further comprising: an image area determination unit configured to determine an image area for a page. 6. An image signal output unit, comprising: an integration unit that integrates the synchronization signal; and an image area determination unit that determines that an image area of one page has been completed based on a result measured by the integration unit. The image forming apparatus according to claim 3, further comprising: 7. An image forming method for forming an image by scanning a plurality of light beams on a photoreceptor, wherein: a scanning step of scanning the photoreceptor and a surrounding recording area by the light beam; A light beam detection step of generating a light beam detection signal by detecting a light beam at a predetermined position outside the area; a recording medium detection step of detecting a leading end and a trailing end of a transported recording medium; A time measuring step of measuring a time for measuring an image area for one page based on a detection result obtained in the recording medium detection step; a detection result obtained in the recording medium detection step and the time measurement Based on the result measured in the step, the light beam detection signal is output as a synchronization signal for synchronizing in the main scanning direction and the sub scanning direction. Image forming method characterized by having a synchronization signal output step for. 8. An image forming method for forming an image by scanning a plurality of light beams on a photosensitive member, wherein: a scanning step of scanning the photosensitive member and a recording area around the photosensitive member with the light beam; A light beam detection step of generating a light beam detection signal by detecting a light beam at a predetermined position outside the area; a recording medium detection step of detecting a leading end and a trailing end of a transported recording medium; A counting step of counting the light beam detection signal to measure an image area for one page based on a detection result obtained by the recording medium detection step; and a detection result obtained by the recording medium detection step. The light beam detection signal is synchronized in the main scanning direction and the sub scanning direction based on the result measured in the counting step. Image forming method characterized by having a synchronization signal output step of outputting as a synchronizing signal for. 9. The image forming method according to claim 7, further comprising an image signal output step of outputting an image signal for modulating the light beam based on the synchronization signal. 10. The image signal outputting step includes: a pulse interval measuring step of measuring a pulse interval of the synchronization signal; and an image area for one page is completed based on a result measured by the pulse interval measuring step. The image forming method according to claim 9, further comprising: an image area end determining step of determining whether or not the image forming apparatus has ended. 11. The image signal outputting step includes: a counting step of counting pulses of the synchronization signal; an image area determining step of determining an image area of one page based on a result counted by the counting step. The image forming method according to claim 9, further comprising: 12. The image signal output step includes: an integration step of integrating the synchronization signal; and an image area determination for determining that an image area for one page has been completed based on a result measured by the integration step. The image forming method according to claim 9, further comprising: 13. A scanning means for scanning a photosensitive member and a recording area around the photosensitive member with a light beam, and a light beam for generating a light beam detection signal by detecting the light beam at a predetermined position corresponding to the outside of the recording area. An image forming apparatus comprising: a detection unit; and a recording medium detection unit that detects a leading end and a trailing end of a conveyed recording medium. The image forming apparatus forms an image by scanning a plurality of light beams on a photoconductor. A storage medium storing a control program for controlling by a computer, the control program is for controlling a computer to measure an image area for one page based on a detection result obtained by the recording medium detection unit. Starts the time measurement, and based on the detection result obtained by the recording medium detection means and the result measured by the time measurement, the light beam detection signal The storage medium storing an image formation control program for causing output as a synchronization signal for synchronizing the main scanning direction and the sub scanning direction. 14. A scanning means for scanning a photosensitive member and a recording area around the photosensitive member with a light beam, and a light beam for generating a light beam detection signal by detecting the light beam at a predetermined position corresponding to the outside of the recording area. An image forming apparatus comprising: a detection unit; and a recording medium detection unit that detects a leading end and a trailing end of a conveyed recording medium. The image forming apparatus forms an image by scanning a plurality of light beams on a photoconductor. A storage medium storing a control program for controlling the image area for one page based on a detection result obtained by the recording medium detection unit. Counting the light beam detection signal. Based on the detection result obtained by the recording medium detection means and the count result, the light beam The storage medium storing the image formation control program, characterized in that for outputting a detection signal as a synchronizing signal for synchronizing the main scanning direction and the sub scanning direction. 15. The image forming apparatus according to claim 13, wherein the control program causes a computer to output an image signal for modulating the light beam based on the synchronization signal. A storage medium storing a control program. 16. The control program causes a computer to measure a pulse interval of the synchronization signal, and determine that one page of image area is completed based on a result measured by the pulse interval measurement. A storage medium storing the image forming control program according to claim 15. 17. The control program according to claim 15, wherein the control program causes a computer to count the pulses of the synchronization signal, and determine an image area for one page based on the count result. A storage medium storing an image formation control program. 18. The control program according to claim 15, wherein the control program causes a computer to integrate the synchronization signal, and determine that one page of image area has ended based on the integration result. A storage medium storing the image forming control program described in the above.