JP2000347482A - Image forming device, its control method, and computer- readable storing medium storing the control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make optimizable the setting of a non-image forming area in accordance with the length in a main scanning direction and the carrying position of a photoreceptor in the main scanning direction when a recording medium is scanned in an image forming device in which the recording medium is carried to the photoreceptor after an image is formed on the photoreceptor by optical scanning, and the image is transferred and recorded to the recording medium. SOLUTION: The length Sx of a recording paper in the main scanning direction is detected, and the timing of mask signal setting the non-image-forming area (release time Tsx of mask and setting time Tex with reference of horizontal synchronizing signal) are set based on the detection result. Besides, the carrying position Px in the main scanning direction of the recording paper S with respect to the photoreceptor is detected, a deviation value Zx=Sx-Px with respect to a regular carrying position is found, a mask adjusting time Tzx in accordance with the value Zx is found, and the timing of the mask signal is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly, to a method of forming an image on a photosensitive member by scanning light, feeding a recording medium to the photosensitive member, and transferring the image to the recording medium. TECHNICAL FIELD The present invention relates to an image forming apparatus for performing recording and control, a control method thereof, and a computer-readable storage medium storing a control program thereof.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using an electrostatographic system has been known as an image forming apparatus of the type described above.
It is configured as described in -160680. That is, the charged photoconductor is scanned with a laser beam modulated by an image signal to form an electrostatic latent image, which is developed as a toner image, and recording paper as a recording medium is fed to the photoconductor ( The image of the developed toner is transferred to a recording sheet, fixed, and recorded.

Conventionally, in this type of image forming apparatus, a non-image forming area on which an image is not formed on a photosensitive member is set in accordance with the length of the fixed or irregular recording paper in the main scanning direction in the above scanning. Timing control was performed.

[0004]

However, according to the above-mentioned conventional technique, the recording paper is moved in the right and left direction (the laser beam) on the photoreceptor due to the variation of the feeding accuracy and the precision of the conveyance path for feeding the recording paper to the photoreceptor. In the main scanning direction). When the width (length in the main scanning direction) of the image forming area for forming an image on the photosensitive member is made equal to the width of the recording paper, the image is formed in an area outside the recording paper due to the shift. As a result, there is a problem in that the recording paper may be stained or an image defect may occur, thereby deteriorating the performance of the image forming apparatus.

The present invention has been made in view of such a point, and in the above-described image forming apparatus, the image forming area on the photosensitive member and the length of the recording medium in the main scanning direction are the same. Even if the feeding position of the recording medium fed to the photoconductor shifts in the main scanning direction, an image is not formed outside the recording medium and an image can be properly formed.

[0006]

According to the present invention, an image is formed on a photoreceptor by scanning light, and a recording medium is fed to the photoreceptor. An image forming apparatus for transferring and recording the image on a medium, a control method thereof, and a computer-readable storage medium storing the control program, wherein the length of the recording medium in the main scanning direction in the scanning and the recording medium The non-image forming area where no image is formed on the photoconductor is set according to the transport position of the photoconductor in the main scanning direction.

More specifically, there is provided a length detecting means for detecting the length of the recording medium in the main scanning direction, or an input means for inputting the length by an operation of a user of the image forming apparatus. Further, there is provided a transfer position detecting means for detecting the transfer position of the recording medium in the main scanning direction, or an input means for inputting the transfer position by an operation of a user of the image forming apparatus. Then, the non-image forming area is set according to the detected or inputted length of the recording medium in the main scanning direction and the transport position.

Alternatively, before setting the non-image forming area, a test image for measuring a transport position of the recording medium in the main scanning direction is formed on the photosensitive member.
The transfer position is detected by the transfer position detecting means based on the test image recorded on the recording medium, or the user of the image forming apparatus measures the transfer position. , Can be input by the input means.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the second and third embodiments, the description of the same parts as those in the first embodiment will be omitted, and only different points will be described.

[First Embodiment] A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows the configuration of the image forming apparatus according to the first embodiment along the conveyance path of the recording paper S in the main body. This image forming apparatus is configured as a laser printer.

In FIG. 1, the main body of the laser printer has a cassette 6 for accommodating recording paper S, and a paper feed roller (pickup roller 7) for feeding out the recording paper S from the cassette 6.
(Comprising a pair of paper feed rollers 9). A pair of registration rollers 32 for synchronously transporting the recording paper S is provided downstream of the paper feed rollers 7 and 9, and an image forming unit of a known electrophotographic process is provided further downstream.

In the configuration of the image forming section, reference numeral 30 denotes a photosensitive member (drum). After the photoconductor 30 is uniformly charged by a charger (not shown), the photoconductor 30 is scanned with a laser beam (beam) modulated by an image signal emitted from a scanner unit 35 to thereby form an electrostatic latent image. An image is formed. This electrostatic latent image is developed as a toner image by a developing device (not shown), and the toner image is transferred by the transfer roller 34 to the recording paper S fed to the photoreceptor 30, and further by the fixing device 31. Be established. Thereafter, the recording paper S is discharged to a paper discharge unit.

A line sensor 33 is provided along the conveyance path of the recording paper S and near the upstream side of the photoconductor 30 in the recording paper conveyance direction. The transport position in the main scanning direction in the scanning is detected. The line sensor 33 is arranged along the main scanning direction, and its length is longer than the maximum length of the recording paper S in the main scanning direction.

Further, as described later, the length of the recording paper S in the main scanning direction and the sub-scanning direction via a regulating plate for regulating the width direction and the vertical direction of the recording paper S, that is, the main scanning direction and the sub-scanning direction. Is detected, and based on the result, it is detected whether or not the recording paper S is the standard size. The detection method is described in, for example,
No. 92821.

Further, a correction means (not shown) for correcting a deviation of the recording paper S in the transport direction is provided. The correcting means measures the transport time of one page of the recording paper by a paper feed sensor and corrects the measurement based on the measured time, as described in, for example, JP-A-5-216333.

Next, FIG. 2 shows a control system of the laser printer of the present embodiment and a configuration of a mechanism around a cassette in which the recording paper S is stored.

In FIG. 2, reference numeral 1 denotes a printer control unit as control means for controlling the entire printer and setting a non-image forming area, which will be described later, and includes a timer (not shown) and a read-only memory (hereinafter referred to as a ROM). , A central processing unit (hereinafter, referred to as CPU) 1a incorporating a random access memory (hereinafter, referred to as RAM) and various input / output control circuits (not shown). Change the corresponding control program to C
It is stored in the ROM of the PU 1a and executed by the CPU 1a.
The printer control unit 1 is a motor driver (motor drive circuit)
The drive and drive speed of the motor 3 are controlled via the control unit 2.
For example, when a pulse motor is used as the motor 3, the driving speed is changed according to the frequency of a pulse signal for driving the motor, or the rotation is switched between normal rotation and reverse rotation. The driving of the paper feed rollers 7 and 9 is performed by the motor 3.

Reference numeral 4 denotes a DC (direct current) power supply for supplying power to the printer control unit 1, and reference numeral 5 denotes a display for displaying information such as the status of the printer.

Reference numeral 10 denotes recording paper S stored in the cassette 6
Is a regulating plate for regulating the main scanning direction of the recording paper S, and maintains the alignment of the recording paper S. The regulating plate 10 is movable in both directions along the conveying direction of the recording paper S, which is indicated by a double-headed arrow in FIG. 2, and along with the movement of the regulating plate 10, a slide resistance 11 with which the regulating plate 10 is slidably contacted. Changes the resistance value.

Reference numerals 12a and 12b denote regulating plates which regulate the sub-scanning direction of the recording paper S stored in the cassette 6 and regulate the position in the main scanning direction, and maintain the alignment of the recording paper S. As shown in FIG. 3, the control plates 12a and 12b are movable by a roller or a gear 14 so as to approach or separate from each other along the main scanning direction.
Along with this movement, the resistance value of the slide resistor 13 with which the regulating plate 12b slidably contacts changes.

The length of the recording paper S in the sub-scanning direction (conveying direction) is detected via the slide resistance 11 and the slide resistance 1 is detected.
3, the length of the recording sheet S in the main scanning direction is detected.
FIG. 4 shows a circuit configuration for that purpose.

As shown in FIG. 4, the voltage divided by the series connection of the slide resistor 11 and the resistors 21 and 22 and the voltage divided by the series connection of the slide resistor 13 and the resistors 23 and 24 are supplied to the printer controller. The input is input to the CPU 1a, A / D converted, and the respective voltage values are recognized.

Here, assuming that each of the divided voltages is VL without discrimination, and is L without discriminating the length of the recording paper S in the sub-scanning direction and the main scanning direction, the voltages VL and The relationship with the length L of the recording paper S is as shown in FIG. That is, La <Lb and Va <Vb, and the length of the recording paper S and the voltage VL have a proportional relationship. From this relationship, CP
U1a obtains data of the length of the recording paper S in the sub-scanning direction and the main scanning direction from the voltage VL based on data stored in the ROM in advance.

The detecting means for detecting the length of the recording paper S in the sub-scanning direction and the detecting means for detecting the length in the main scanning direction are not limited to those described above. May be.

In this embodiment, before the recording paper S is fed and the image (toner image) is transferred onto the recording paper S at the photoconductor 30, the recording paper S is detected by the line sensor 33 described above. The transport position information Px in the main scanning direction with respect to the photoconductor 30 is detected. Here, the transport position information Px is, specifically, as shown in FIG. 6, from one end (left end in the figure) of the normal transport position of the recording paper S in the main scanning direction. This is information on the length up to the other end (the right end in the figure) of the transport position. Note that the means for detecting the transport position of the recording paper S in the main scanning direction is not limited to the line sensor, and may be, for example, an electrical detection means.

In this embodiment, the difference between the length Sx of the recording paper S in the main scanning direction detected in the configuration of FIG. 4 and the transport position information Px detected by the line sensor 33, that is, the recording paper S The mask adjustment time Tzx Tzx = Zx / V (V is the scanning speed) is obtained from the shift value Zx = Sx-Px of the actual transport position in the main scanning direction with respect to the normal transport position in the main scanning direction with respect to the photoconductor 30. Tzx has a value of +-on the left and right with respect to the reference position.

Here, the mask adjustment time Tzx is a mask signal shown in FIG. 6, that is, a non-image in which an image is not formed by performing masking for inhibiting image formation (prohibiting emission of scanning laser light) on the photosensitive member. This is the time for adjusting the timing of the signal for setting the formation region. Further, in FIG.
sx is the time from the rising of the horizontal synchronizing signal for synchronizing the main scanning to the falling (unmasking) of the reference uncorrected mask signal (hereinafter referred to as the non-image forming area canceling time). Further, the time Tex is a time from the rising of the horizontal synchronization signal to the rising of the mask signal before correction (mask setting) serving as a reference (hereinafter, referred to as a setting time of the non-image forming area).

The mask adjustment time Tzx is added to the non-image forming area release time Tsx and the set time Tex to correct the timing of the mask signal. As a result, the timing of the fall (mask release) and the rise (mask setting) of the corrected mask signal correspond to both ends of the actual transport position of the recording paper S in the main scanning direction, and the non-image on the photosensitive member The formation area is set to an area outside each of both ends of the conveying position of the recording paper S in the main scanning direction, and
The upper image forming area 41 can be set so as to match the recording paper S in accordance with the shift of the transport position of the recording paper S in the main scanning direction.

The unblanking signal in FIG.
The signal is a signal for emitting laser light in an area that protrudes from the photoconductor, that is, a so-called unblanking area, within the range of scanning of the laser light that scans the photoconductor.

The setting of the non-image forming area is performed not only in the above-described main scanning direction but also in the sub-scanning direction.

Next, the processing operation for setting the above-described non-image forming area performed by the CPU 1a of the printer control section 1 will be described with reference to FIG. The flowchart of FIG. 7 shows a processing procedure for setting a non-image forming area. A corresponding control program is stored in the ROM of the CPU 1a.
a. The ROM corresponds to an embodiment of a computer-readable storage medium storing a control program of the image forming apparatus according to the present invention.

In the initial state at the start of the processing of the flowchart of FIG. 7, the shift value Zx and the mask adjustment time Tzx of the transport position of the recording paper S in the main scanning direction are 0.
Is set to

In this state, the process is started. First, the process waits until the start of sheet feeding is determined (step S1). When the start of sheet feeding is determined, the following process is performed.

That is, the recording paper S having the configuration shown in FIG.
It is determined whether the recording sheet S to be fed is a fixed-size recording sheet (for example, A4 size or the like) based on the detection outputs of the lengths in the main scanning direction and the sub-scanning direction (step S2). For example, the release times Tsx and Tsy and the set times Tex and Tey of the non-image forming areas in the main scanning direction and the sub-scanning direction (recording paper conveyance direction) are respectively set to predetermined Tsxc and Tsyc in accordance with the recording paper size. , Texc, Teyc (step S
3).

On the other hand, if the recording paper S to be fed is a non-standard recording paper, the length Sy of the recording paper S in the sub-scanning direction and the process speed (sub-scanning speed) detected by the configuration shown in FIG.
Thus, the cancellation of the non-image forming area in the sub-scanning direction and the set times Tsy and Tey are determined to be Tsyx and Teyx by calculation.
In accordance with the length Sx of the recording paper detected in the main scanning direction in the configuration of FIG. 4, the non-image forming area in the main scanning direction and the set times Tsx and Tex are determined to Tsxx and Texx by calculation (step S4).

Next, after step S3 or S4, the process proceeds to step S5, where the transport position information Px of the recording paper S in the main scanning direction detected by the line sensor 33 and the recording position information of the recording paper S in the main scanning direction are detected. The shift value Zx of the transport position of the recording sheet S in the main scanning direction is obtained from the length Sx, and the mask adjustment time Tzx is obtained from the deviation value Zx and the main scanning speed V. This is used to release and set the non-image forming area in the main scanning direction. The times Tsx and Tex are corrected and set in addition to the times Tsx and Tex.

Thus, the timing of the mask signal is set, and the non-image forming area is set. Step S5
Is completed, the non-image forming area setting processing routine is terminated, and the process returns to the main routine. In this manner, the non-image forming area can be set according to the deviation of the length of the recording sheet S in the main scanning direction and the transport position.

In the main routine, an image is formed on the photosensitive member 30 based on the setting of the non-image forming area.
The image is transferred and recorded on the fed recording paper S. Here, by adding the same adjustment time as the mask adjustment time Tzx to the image writing timing time in the same manner, it becomes possible to print an image having the same length as the recording paper on the recording paper S in the main scanning direction.

As described above, according to this embodiment, the setting of the non-image forming area can be optimized according to the length of the recording paper in the main scanning direction and the transport position of the recording paper in the main scanning direction. Assuming that the length of the image forming area on the photoconductor and the length of the recording paper in the main scanning direction are the same, even if the transport position of the recording paper fed to the photoconductor is shifted in the main scanning direction, the It is possible to form an image on the entire area of the recording paper without forming the image, and it is possible to form an image properly without causing stains or image defects on the recording paper.

[Second Embodiment] Next, a second embodiment of the present invention will be described. The difference of the second embodiment from the first embodiment described above is that, in the configuration of FIG. 2, reference numeral 5 denotes a display unit, an input unit including various input keys including ten-keys, or an input unit such as a touch panel. It is assumed that the operation unit is provided. Then, a predetermined test image for measuring the transport position of the recording paper S in the main scanning direction is recorded on the recording paper S by the test image signal shown in FIG. The deviation value Zx of the transport position of the recording paper S in the main scanning direction is measured from the test image recorded in the operation unit 5, and the data of the deviation value Zx is converted into the number of copies of the copying machine by operating the ten keys or the like of the input unit of the operation unit 5. The setting can be input in the same manner as the setting.

The CPU 1a of the print control unit 1 determines the shift value Zx input from the input unit of the operation unit 5 and the length of the recording paper in the main scanning direction detected in the same manner as in the first embodiment. As in the first embodiment, a process of setting a non-image forming area is performed.

In the configuration of the present embodiment, the detection mechanism for detecting the transport position of the recording paper S in the main scanning direction by the line sensor 33 in the first embodiment may be omitted, or the detection mechanism may be provided. User's deviation value Zx
May be given priority over the detection data of the detection mechanism.

FIG. 9 shows an example of the above test image.
Will be described. As shown in FIG. 9, a test image signal is output from the CPU 1a of the printer control unit 1 together with a mask signal based on the horizontal synchronization signal. As an example, the test image signal is set so that a measurement line is drawn along the sub-scanning direction at the center (design value) of the recording paper S in the main scanning direction. At this time, the test image signal is transmitted to the scanner unit 35 which scans the photosensitive member 30 with a laser beam to form an image.
A drive signal for emitting and extinguishing a semiconductor laser (not shown) that is a light emitting element that emits the laser light. In order to form a measurement line in the center of the recording paper S along the sub-scanning direction, the driving signal is formed so that the driving of the semiconductor laser is performed in the order of light emission → light-off → light emission → light-off.

With respect to the recording paper S on which a test image including such measurement lines is recorded, the user shifts the measurement line from the center in the main scanning direction of the recording paper S shown in FIG. The deviation value Zx of the transport position in the direction can be easily measured with a ruler or the like.

The reason for making the test image as described above will be described below. FIG. 11 shows a driving signal of the semiconductor laser and timing of light emission. As shown here, when pulse driving is performed, the semiconductor laser emits light with a delay from the drive signal (light emission delay time Td1). Further, if the pulse driving is performed again without time after turning off the light, the delay time is reduced (light emission delay time Td2). Although it is possible to reduce the delay by flowing the bias current, it is possible to further improve the effect by combining them.

From this, the state before forming the measurement line of the test image is changed from light emission to off, and the measurement line is formed by light emission again, so that the light emission delay time Td1
Is shortened to Td2, the position of the formed measurement line in the main scanning direction is brought close to the design value, and the state before the measurement line is determined, thereby stabilizing the light emission for forming the measurement line and emitting light. Variations in the delay time Td2 can be eliminated.

As described above, by setting the test image signal, the position accuracy of the measurement line in the main scanning direction is increased,
The accuracy of setting the non-image forming area can be improved.

According to the above-described embodiment, the recording of the test image allows the photosensitive member 30 at the time of the actual image formation.
At the position of the conveyance position of the recording paper S in the main scanning direction Zx
Can be obtained, the deviation value Zx can be obtained with higher accuracy than the deviation value Zx is obtained at the line sensor 33 on the near side in the transport direction from the photoconductor 30 as in the first embodiment. The setting of the non-image forming area can be performed with higher accuracy.

Further, it is not necessary to provide a detection mechanism for detecting the transport position of the recording paper in the main scanning direction by the line sensor 33, so that the configuration of the apparatus can be made simpler and less expensive.
Alternatively, if the detection mechanism is provided and there is input data of the deviation value Zx from the user, it is possible to select such that priority is given to the detection data of the detection mechanism, and the like.
More optimal control can be performed.

As in the first embodiment, the setting of the non-image forming area can be optimized according to the length of the recording paper in the main scanning direction and the transport position, and an image can be formed properly.
The performance of the image forming apparatus can be improved.

In this embodiment, a test image is recorded on a recording sheet for setting a non-image forming area, and one recording sheet is consumed. Therefore, a non-image is formed every time an image is formed on one recording sheet. It is not realistic to set the formation area. For example, the non-image formation area may be set every time the recording paper is loaded or replenished to the cassette 6.

Further, in this embodiment, the user of the apparatus inputs the shift value Zx of the transport position of the recording paper in the main scanning direction by operating the input unit of the operation unit 5, and the length of the recording paper in the main scanning direction is obtained. Is detected in the configuration of FIG. 4, but the length of the recording paper in the main scanning direction may also be input by the user from the input unit. In any case, the CPU 1a sets the non-image forming area according to the length of the detected or input recording paper in the main scanning direction and the input transport position in the main scanning direction (specifically, the deviation value Zx). Is stored in its own ROM and executed.

Although significantly different from this embodiment, the transport position of the recording paper in the main scanning direction is detected by a line sensor or the like.
The length of the recording paper in the main scanning direction may be input by the user from the input unit. In this case, the CPU 1a performs control for setting the non-image forming area in accordance with the input length of the recording paper in the main scanning direction and the detected transport position in the main scanning direction (specifically, the deviation value Zx). Program your own RO
It is stored in M and executed.

[Third Embodiment] Next, a third embodiment of the present invention will be described with reference to FIGS.

FIG. 12 shows the configuration of the image forming apparatus of this embodiment. As shown here, in the apparatus of the present embodiment, the line sensor 33 in the configuration of the first embodiment is used.
And a line sensor 51 is provided in the paper discharge unit instead. In the present embodiment, the test image described in the second embodiment is recorded on the recording paper S, the position of the measurement line of the test image is detected by the line sensor 51, and the test image in the main scanning direction of the recording paper S is detected. The shift value Zx of the transport position is obtained, and based on the shift value Zx, the timing of the mask signal is corrected, and the non-image forming area is set.

Details of the process of setting the non-image forming area will be described with reference to the flowchart of FIG. FIG.
Shows a processing procedure for setting a non-image forming area, and a control program corresponding to the setting procedure is executed by the CPU 1a of the printer control unit 1.
Is stored in the ROM and executed by the CPU 1a.

Steps S1 to S4 in FIG. 13 are common to steps S1 to S4 in FIG. 7 of the first embodiment, and a description thereof will be omitted.

After step S3 or S4, step S3
Proceeding to 50, a test image including the above-described measurement line is formed on the photoconductor 30 based on the setting of the non-image forming area in step S3 or S4, and is transferred to the recording paper S.

Next, it is determined whether or not the recording paper on which the test image has been transferred has been ejected from the fixing device 31 (step S5).
1) When the sheet is discharged, the position of the measurement line of the test image on the recording sheet S in the main scanning direction is detected by the line sensor 51 disposed downstream of the fixing device 31 in the transport direction, and the position is already obtained. From the length of the recording paper S in the main scanning direction, the deviation value Zx of the conveyance position of the recording paper S in the main scanning direction (the deviation of the position of the measurement line with respect to the center of the recording paper S in the main scanning direction)
Is obtained (step S52).

Thereafter, a mask adjustment time Tzx is obtained from the shift value Zx and the main scanning speed V, and this is added to the release of the non-image forming area in the main scanning direction and the set times Tsx and Tex to correct the times Tsx and Tex. (Step S5)
3).

The timing of the mask signal is set in this way, and the non-image forming area is set. Step S5
When Step 3 is completed, the routine of the non-image forming area setting process ends, and the process returns to the main routine. In this manner, the non-image forming area can be set according to the deviation of the length of the recording sheet S in the main scanning direction and the transport position. The length of the recording paper S in the main scanning direction may be detected in the same manner as in the first embodiment, or may be input by a user of the apparatus by operating the input unit.

According to the present embodiment, the shift value Zx can be automatically obtained, and there is no need for the user to measure and input the shift value Zx as in the second embodiment.
Further, similarly to the second embodiment, the deviation value Zx can be obtained with higher accuracy than in the first embodiment, and the setting of the non-image forming area can be performed with higher accuracy.

As in the first embodiment, the setting of the non-image forming area is optimized according to the length of the recording paper in the main scanning direction and the transport position, so that an image can be formed properly. Of course, the performance of the device can be improved.

[0065]

As is apparent from the above description, according to the present invention, after an image is formed on a photoreceptor by scanning light, a recording medium is fed to the photoreceptor, and the recording medium is supplied to the recording medium. In an image forming apparatus that transfers and records an image, the setting of the non-image forming area is optimized according to the length of the recording medium in the main scanning direction in the scanning and the transport position of the recording medium with respect to the photoconductor in the main scanning direction. Even if the conveyance position of the recording medium fed to the photoconductor is shifted in the main scanning direction, the length of the image forming area on the photoconductor and the length of the recording medium in the main scanning direction are the same. Without forming an image outside the medium, it is possible to form an image on the entire area of the recording medium, without causing stains and image defects on the recording medium,
An excellent effect that an image can be formed properly and the performance of the image forming apparatus can be improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a configuration along a recording paper conveyance path in an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating a control system of the apparatus and a configuration of a mechanism around a cassette storing recording paper.

FIG. 3 is a plan view showing an interlocking structure of a regulating plate in a sub-scanning direction of recording paper of the apparatus.

FIG. 4 is a block circuit diagram showing a circuit configuration for detecting the length of the recording paper in the main scanning direction and the sub-scanning direction in the apparatus.

FIG. 5 is a graph showing a relationship between a recording paper length and a voltage in the circuit of FIG. 4;

FIG. 6 is a timing chart showing timing correction of a mask signal for setting a non-image forming area in the apparatus.

FIG. 7 is a flowchart illustrating a control procedure of a setting process of a non-image forming area in the apparatus.

FIG. 8 is a timing chart illustrating a test image signal in the image forming apparatus according to the second embodiment.

FIG. 9 is a timing chart illustrating an example of the test image signal and a test image formed by the test image signal.

FIG. 10 is a plan view for explaining a method of measuring a shift value Zx of the transport position of the recording paper S in the main scanning direction using the test image.

FIG. 11 is a timing chart showing a light emission delay with respect to a drive signal of a semiconductor laser.

FIG. 12 is a schematic configuration diagram illustrating a configuration along a recording paper conveyance path in an image forming apparatus according to a third embodiment.

FIG. 13 is a flowchart illustrating a control procedure of a setting process of a non-image forming area in the apparatus.

[Explanation of symbols]

 Reference Signs List 1 printer control unit 1a CPU 2 motor driver 3 motor 4 DC power supply 6 cassette 7 pickup roller 9 transport roller 10, 12a, 12b regulating plate 11, 13 slide resistance 21, 22, 23, 24 resistance 30 photoconductor 31 fixing device 33, 51 Line sensor 35 Scanner unit 41 Image forming area S Recording paper

Claims (21)

[Claims] 1. An image forming apparatus for forming an image on a photoreceptor by scanning light, feeding a recording medium to the photoreceptor, transferring the image to the recording medium, and recording the image, the recording medium comprising: Control means for setting a non-image forming area where no image is formed on the photoconductor in accordance with the length of the recording medium in the main scanning direction and the transport position of the recording medium with respect to the photoconductor in the main scanning direction. An image forming apparatus comprising: 2. A control device, comprising: a length detecting unit for detecting a length of the recording medium in the main scanning direction; and a transport position detecting unit for detecting a transport position of the recording medium in the main scanning direction. 2. The image according to claim 1, wherein the non-image forming area is set according to the length detected by the length detecting unit and the transport position detected by the transport position detecting unit. 3. Forming equipment. 3. A length detecting means for detecting a length of the recording medium in the main scanning direction, and an input means for inputting a conveying position of the recording medium in the main scanning direction by an operation of a user of an image forming apparatus. The control unit sets the non-image forming area according to the length detected by the length detection unit and the transport position input by the input unit. 2. The image forming apparatus according to 1. 4. An input unit for inputting a length of the recording medium in the main scanning direction by an operation of a user of the image forming apparatus, and a conveying position detecting unit for detecting a conveying position of the recording medium in the main scanning direction. The control unit sets the non-image forming area according to the length input by the input unit and the transport position detected by the transport position detection unit. 2. The image forming apparatus according to 1. 5. An image forming apparatus comprising: input means for inputting a length of the recording medium in the main scanning direction and a transport position of the recording medium in the main scanning direction by an operation of a user of the image forming apparatus; The image forming apparatus according to claim 1, wherein the non-image forming area is set according to the length and the transport position input by the input unit. 6. The control unit, before setting the non-image forming area, outputs a test image for measuring a transport position of the recording medium in the main scanning direction, and emits light for scanning the photosensitive member. The light emitting element is configured to emit light, emit light, emit light, form the photosensitive member by light emission, transfer the image to a recording medium, and record the image. The conveyance position detection unit performs the conveyance based on a test image recorded on the recording medium. The image forming apparatus according to claim 2, wherein the position is detected. 7. The method according to claim 1, wherein the control unit sets a test image for measuring a transport position of the recording medium in the main scanning direction before setting the non-image forming area, and emits a light for scanning the photosensitive member. The light emitting device emits light, emits light, emits light, and is formed on the photoreceptor by transferring the light to a recording medium for recording. The test image recorded on the recording medium allows the user of the image forming apparatus to transport the image. The image forming apparatus according to claim 3, wherein a position is measured, and the position can be input by the input unit. 8. A control method of an image forming apparatus for forming an image on a photoconductor by scanning light, feeding a recording medium to the photoconductor, and transferring and recording the image on the recording medium. In accordance with the length of the recording medium in the main scanning direction in the scanning and the transport position of the recording medium with respect to the photoconductor in the main scanning direction, setting a non-image forming area where no image is formed on the photoconductor. A method for controlling an image forming apparatus. 9. The method according to claim 1, wherein the length detection unit detects a length of the recording medium in the main scanning direction, and a conveyance position detection unit detects a conveyance position of the recording medium in the main scanning direction. 9. The method according to claim 8, wherein the non-image forming area is set in accordance with the length detected by the unit and the transport position detected by the transport position detecting unit. 10. A length detecting means for detecting a length of the recording medium in the main scanning direction, and an input means for inputting a conveying position of the recording medium in the main scanning direction by an operation of a user of an image forming apparatus. The image forming apparatus according to claim 8, wherein the non-image forming area is set according to the length detected by the length detecting unit and the transport position input by the input unit. How to control the device. 11. An input unit for inputting a length of the recording medium in the main scanning direction by an operation of a user of the image forming apparatus, and a conveying position detecting unit for detecting a conveying position of the recording medium in the main scanning direction. 9. The image forming apparatus according to claim 8, wherein the non-image forming area is set according to the length input by the input unit and the transport position detected by the transport position detecting unit. How to control the device. 12. An input unit for inputting a length of the recording medium in the main scanning direction and a transport position of the recording medium in the main scanning direction by an operation of a user of the image forming apparatus, wherein the input unit inputs the length. 9. The method according to claim 8, wherein the non-image forming area is set according to the length and the transport position. 13. Before setting the non-image forming area,
A test image for measuring the transport position of the recording medium in the main scanning direction is formed on the photoconductor by light emission of a light emitting element that emits light for scanning on the photoconductor, extinguishment, and light emission. The method according to claim 9, wherein the transfer position is transferred, and the transfer position detecting unit detects the transfer position based on a test image recorded on the recording medium. 14. Before setting the non-image forming area,
A test image for measuring the transport position of the recording medium in the main scanning direction is formed on the photoconductor by light emission of a light emitting element that emits light for scanning on the photoconductor, extinguishment, and light emission. 13. The image forming apparatus according to claim 10, wherein the image is transferred and recorded, and a user of the image forming apparatus measures the transport position based on a test image recorded on the recording medium, and allows the user to input the transport position using the input unit. The control method of the image forming apparatus described in the above. 15. A control program for an image forming apparatus for forming an image on a photoconductor by scanning light, feeding a recording medium to the photoconductor, and transferring and recording the image on the recording medium. A computer-readable storage medium, wherein an image is formed on the photoconductor according to a length of the recording medium in the main scanning direction in the scanning and a transport position of the recording medium with respect to the photoconductor in the main scanning direction. A storage medium storing a control program for setting a non-image forming area not to be used. 16. A method for detecting a length of a recording medium, comprising: detecting a length of the recording medium in the main scanning direction; and detecting a conveying position of the recording medium in the main scanning direction. 16. The control program according to claim 15, wherein a control program for setting the non-image forming area according to the length detected by the unit and the transport position detected by the transport position detecting unit is stored. Storage medium. 17. A length detecting means for detecting a length of the recording medium in the main scanning direction, and an input means for inputting a conveying position of the recording medium in the main scanning direction by an operation of a user of an image forming apparatus. Wherein a control program for setting the non-image forming area according to the length detected by the length detecting means and the transport position input by the input means is stored. Item 16. The storage medium according to Item 15. 18. An input unit for inputting a length of the recording medium in the main scanning direction by an operation of a user of the image forming apparatus, and a conveying position detecting unit for detecting a conveying position of the recording medium in the main scanning direction. Wherein a control program for setting the non-image forming area according to the length input by the input means and the transport position detected by the transport position detecting means is stored. Item 16. The storage medium according to Item 15. 19. An input unit for inputting a length of the recording medium in the main scanning direction and a transport position of the recording medium in the main scanning direction by an operation of a user of the image forming apparatus, The storage medium according to claim 15, wherein a control program for setting the non-image forming area according to the length and the transport position is stored. 20. Before setting the non-image forming area,
A test image for measuring the transport position of the recording medium in the main scanning direction is formed on the photoconductor, transferred to a recording medium and recorded, and the test recorded on the recording medium is performed by the transport position detection unit. 19. The storage medium according to claim 16, wherein a control program for detecting the transport position by an image is stored. 21. Before setting the non-image forming area,
A test image for measuring the transport position of the recording medium in the main scanning direction is formed on the photoconductor, transferred to a recording medium and recorded, and a test image recorded on the recording medium is used for the image forming apparatus. 20. The storage medium according to claim 17, wherein a control program for allowing a user to measure the transport position and input the measured position using the input unit is stored.