JPH1063052A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of carrying a recording sheet whose size is two times larger than a prescribed size, forming two images corresponding thereto and preventing the positional deviations of the images of the recording sheet, in an image forming device capable of carrying two size recording sheets having prescribed size, side by side, and forming the images on the respective recording sheets. SOLUTION: When two A4-size paper sheets are carried side by side at a fixed gap (corresponding to ΔT), to form the first and second images (a), setting is attained so that the time difference (Ts 2-Ts 1) between write stating times of the first and second images Ts 1 and Ts 2 is (W+ΔT) (W corresponds to the length in a lateral direction of A4-size). On the other hand, when an A3-size paper sheet is carried to form the first and second images (b), setting is attained so that the time difference (Ts 2-Ts 1) is W. Thus, in either case of (a) and (b), the first and second images are formed in the same position on the A4-size papers.

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 such as a copying machine or a laser printer capable of forming two or more images in parallel on recording sheets conveyed in parallel.

[0002]

2. Description of the Related Art In general, an image forming apparatus such as a copying machine forms an image on a photosensitive drum or the like by scanning signal light based on input image data, and forms the formed image. The image is transferred onto the recording sheet by moving the recording sheet to the transfer position while moving the recording sheet to the transfer position.

As image forming apparatuses have become widespread, there has been a demand for high-speed processing for forming images on a large number of recording sheets in a short period of time. In particular, a demand for high-speed processing has been increasing in the field of digital copying machines. In order to respond to the demand for higher processing speeds, internal mechanical parts such as the rotation of the photosensitive drum and the transfer sheet transfer operation have been sped up, but in terms of image forming accuracy and paper handling. There is a limit from.

On the other hand, Japanese Patent Application Laid-Open No. 61-192640 discloses
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. Hei. 2-24673, a parallel transport type copying machine has been developed which transports two recording sheets in parallel and forms an image on each of them.
In a parallel-conveying type copying machine, copying can be performed on two or more recording sheets in one copying operation, so that the copying processing speed can be doubled without difficulty.

Meanwhile, among parallel-conveying-type image forming apparatuses, there have been developed ones having a function of conveying a large-sized recording sheet alone and forming an image thereon. For example, a small recording sheet such as A4
Copiers have also been developed which can convey images one by one and form an image on each of them, and can convey a large recording sheet such as A3 size alone and form an image on it.

[0006]

SUMMARY OF THE INVENTION
In an image forming apparatus capable of forming an image by conveying a recording sheet of A3 size in parallel, and forming an image by conveying a recording sheet of A3 size, an A3 size transfer sheet is conveyed, and an A4 size transfer sheet is fed to the transfer sheet. It is also conceivable to provide a function of forming two images in parallel. As a result, even when the A4 size recording sheet runs out, if the A3 size recording sheet is conveyed, two A4 size equivalent images are formed thereon, and cut in half, two A4 size recording sheets are cut. Can be obtained substantially as in forming an image on a recording sheet.

However, in this case, when two images are formed on an A3 size recording sheet, the position of the image with respect to the sheet is slightly smaller than when forming images on each of two A4 size recording sheets. The problem of deviation occurs.
That is, when two A4 size recording sheets are conveyed in parallel, they are conveyed with a certain gap in order to avoid mutual interference, and two image forming positions are set accordingly. Therefore, when a recording sheet of A3 size is conveyed and two images are similarly formed on the recording sheet, the two images are too close to each other by the gap, and after the recording sheet is cut into two sheets of A4 size, A displacement will occur.

Note that such a relationship is based on the relationship between the A3 size and the A3 size.
This occurs not only between the four sizes, but also between the B4 size and the B5 size, and between the A4 size and the A5 size. SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an image forming apparatus capable of conveying two recording sheets of a predetermined size in parallel and forming an image on each of the recording sheets has a size twice as large as the predetermined size. It is an object of the present invention to provide a recording sheet capable of transporting a recording sheet having a size of?

[0009]

In order to achieve the above object, an image forming apparatus according to the present invention comprises a first transport mode in which two recording sheets of a predetermined size are conveyed in parallel while maintaining a predetermined gap, and an image forming apparatus having a predetermined size. Conveying means for conveying the recording sheet in a second conveying mode for conveying a recording sheet of twice the size, image forming means for forming two images in parallel on the recording sheet conveyed by the conveying means, conveying means When the recording sheet is transported in the second transport mode, the interval between the two images formed in parallel by the image forming means is determined by a predetermined interval from the two image intervals when the transport means transports the recording sheet in the first transport mode. And an image forming interval adjusting means for narrowing by an amount corresponding to the gap.

This makes it possible to convey a recording sheet having a size twice as large as a predetermined size in the second conveyance mode to form two images on the recording sheet, and to provide image forming interval adjusting means. Therefore, in the second transport mode, an image is formed at the same position with respect to the recording sheet as in the first transport mode. Further, in the second transport mode, a configuration is provided in which the recording sheet having a size twice as large as the predetermined size conveyed by the conveyance unit is divided into two equal portions of a predetermined size after image formation. It can also be cut into two recording sheets of a predetermined size.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described below using a digital copying machine as an example. [Description of Overall Configuration of Digital Copier] FIG.
FIG. 1 is a diagram illustrating an entire configuration of a digital copying machine (hereinafter, simply referred to as “copier”) according to the present invention.

The copying machine 1 is roughly divided into an image reader section 10 for reading an image of a document, and a printer section for reproducing an image read by the image reader section 10 on paper (or a sheet such as an OHP film). The printer unit 20 can transport an A4 size sheet in parallel, or transport an A3 size sheet or an A4 size sheet alone to form an image thereon. It has become.

In FIG. 1, the right side of the paper corresponds to the printer unit 20.
The paper transport direction (hereinafter, simply referred to as “transport direction”) and the front surface of the paper are the main scanning directions when the printer unit 20 writes an image. [Description of Image Reader Unit 10] On the upper surface of the image reader unit 10, a document cover 2 with an automatic document feeder (ADF) can be opened to a transparent document glass plate 15 with its rear end as an axis. Mounted on

The original to be read is automatically supplied on the original glass plate 15 by the ADF, or
5. Place on top. The scanner 11 includes an exposure lamp 12 that irradiates a document, a rod lens array 13 that collects light reflected from the document, and a close-contact CCD sensor 14 that converts the collected light into an electric signal. When reading a document, the scanner 11 is driven by the scanner motor M2 to move in the transport direction (the direction of the arrow in the drawing), and scans the document placed on the document glass plate 15. At this time, the document cover 2 is fixed so that the document does not move, and also prevents the light of the exposure lamp 12 from escaping to the outside.

The light emitted from the exposure lamp 12 of the scanner 11 to the original image is photoelectrically converted by the CCD sensor 14 and sent to the control unit 100 as image data. The image reader unit 10 operates in synchronization with the operation of the printer unit 20 under the control of the control unit 100. [Description of Printer Unit 20] First, a mechanism for forming an image will be described.

In the control unit 100, the image reader unit 10
A / D converted image data from the digital camera and temporarily stored as a digital signal. Then, as described below, this image data is output as a drive signal for the laser diode 21 and reproduced on the image forming area S of the photosensitive drum 27.
The photoreceptor drum 27 removes residual toner on the photoreceptor surface by a cleaner 28 before being exposed to light, and is further discharged by irradiating an eraser lamp 29, and then a charging charger 30 disposed corresponding to the image forming area S. Is charged uniformly. Then, the photoconductor on the surface of the photoconductor drum 27 receives exposure from the laser diode 21 in a state of being uniformly charged.

The laser light emitted from the laser diode 21 passes through a collimator lens 22 to become parallel rays, and then is reflected by a mirror surface of a polygon mirror 23 rotated at a constant speed by a polygon motor 24, so that the fθ lens 2
5, the light is reflected by the folding mirrors 26a and 26b, and the surface of the photosensitive drum 27 is exposed and scanned in the longitudinal direction (main scanning direction). Thereby, an electrostatic latent image is formed in the image forming area S.

The writing timing at this time is controlled by a printer control unit 130 described later. The length of the photosensitive drum 27 is set to be slightly longer than the length of the A3 size in the longitudinal direction. FIG. 2 is a perspective view showing a configuration of a main part around the photosensitive drum 27 in the copying machine 1. In this figure, folding mirrors 26a and 26b
And cleaner 28, eraser lamp 29, transport belt 33
Are omitted, and only the reflection surface of the polygon mirror 23 is shown.

As shown in the figure, when a laser beam is incident at a scanning angle slightly smaller than the scanning angle at the image forming start position of the image forming area S on the photosensitive drum 27, the SOS ("Start Of Scan") detects this. ) Is provided. This SOS sensor 4
0 is a photoelectric conversion element such as a photodiode,
The laser beam reflected by the polygon mirror 23 is reflected by the fθ lens 2
5, after passing through the SOS sensor 40, it is converted into an electric signal (hereinafter referred to as an SOS signal) and sent to the printer control unit 130 (see FIG. 4). Printer control unit 1
At 30, the write timing in the main scanning direction is determined based on the SOS signal.

The electrostatic latent image formed in the image forming area S is developed by the developing device 31 so that the photosensitive drum 27
A toner image is formed on the surface. This developing device 31
For example, in a two-component developing device, the toner and the carrier housed therein are agitated to give a charge to the toner, and the toner is supplied to the surface of the photosensitive drum 27 via the developing roller 311 to perform development. I do.

Next, a mechanism for feeding and conveying a sheet will be described. As shown in FIG. 1, paper cassettes 50a and 50b are mounted on the upper and lower tiers on the side opposite to the transport direction of the printer unit 20, and paper feed rollers 51a and 52a are provided for the paper cassette 50a. Is the paper cassette 50
Paper feed rollers 51b and 52b are attached to b.

As shown in FIG. 2, two A4 size sheets are stored in the paper cassette 50a in parallel in the vertical paper passing direction (the longitudinal direction of the paper is the same as the transport direction). Although not shown, A3 size paper is stored alone in the horizontal paper passing direction (the longitudinal direction of the paper is orthogonal to the transport direction). The paper stored in the paper cassette 50a and the paper cassette 50b is pressed by a pressure plate (not shown).
Paper feed rollers 51a, 52a and
b, 52b.

Each paper feed roller 51a, 52a, 51b, 5
2b is rotated by the driving force of the main motor M1 (see FIG. 1). The control is performed by a paper feed clutch (not shown). When the paper feed rollers 51a and 52a are driven to rotate, two A4 size sheets stored in the paper cassette 50a are fed out in parallel, and the paper feed rollers 51b , 52b, the A3-size sheets stored in the sheet cassette 50b are fed out.

The printer unit 20 is provided with a paper sensor (not shown) for detecting the presence or absence of paper stored in the mounted paper cassettes 50a and 50b, and the detected information is notified to the control unit 100. You. As will be described later, the printer control unit 130 uses this information to select from which of the paper cassettes 50a and 50b paper is to be fed and whether to perform cutting.

The paper fed from the paper cassettes 50a and 50b is temporarily stopped by the timing roller 34 and sent out in synchronization with the image formed on the photosensitive drum 27. When A4-size sheets are supplied in parallel from the sheet cassette 50a, the leading ends of the two sheets are simultaneously sent out by the timing roller. The sheet sent from the timing roller 34 is transported by the transport belt 33 to a transfer position below the photosensitive drum 27.
The timing roller 34 and the transport belt 33 are also driven to rotate by the driving force of the main motor M1.

A transfer charger 32 is provided behind the transfer belt 33 at the transfer position. This transfer charger 3
2 generates an electric charge and transfers the toner image formed on the photosensitive drum 27 onto the sheet by electrostatic force. The sheet on which the toner image has been transferred is transported to the fixing device 36 by the transport belt 35. The fixing device 36 fixes the toner between the paper fibers by pressing the paper while heating it with a fixing roller 361 having a built-in heater, and discharges the paper onto a paper discharge tray 37 by a paper discharge roller 362. I do.

FIG. 3 is a perspective view showing a sheet cutting mechanism provided in the copying machine 1. The paper cutting mechanism is for dividing an A3-size sheet into two after image formation, and includes a fixing roller 361 in the fixing device 36 and a discharge roller 3.
A circular cutter 363 provided between the circular cutter 362, an engaging roller 364 having a groove 364 a engaging with the circular cutter 363, and a solenoid 365 for vertically moving the circular cutter 363.

When the solenoid 365 is not operated, the transported A3 size paper is a circular cutter 363.
And through the engagement roller 364, but when the solenoid 365 is operating, the circular cutter 3
Since the 63 is engaged with the groove 364a, the transported A3-size paper is cut into two A4-size papers here.

[Description of Operation Panel 17 and Control Unit 100] An operation panel 17 shown in FIG. The operation panel 17 displays the set paper size mode, number of copies, copy density, magnification, and the like.
The user can perform an input operation to instruct them by touching a predetermined display surface, and when a paper jam (jam) or paper shortage occurs, the occurrence of the abnormality is displayed.

The paper size mode is used to specify a paper size when copying is completed and the paper is ejected from the copying machine 1. In this copying machine 1, the user can select the A3 size or the A4 size.
One of the paper size modes of the size can be designated. Paper size mode input from the operation panel 17,
The designated number of copies, the magnification, and the like are stored in the control unit 100,
The control unit 100 sets the transport mode and the image to be formed based on the input.

In the transport mode, the sheet cassette 50a
4 size paper is fed or transported, or the paper cassette 50b
Indicates whether to feed and convey A3 size paper, and its setting will be described later. FIG.
It is a block diagram of 00. The control unit 100 includes an image signal processing unit 120 and a printer control unit 130.

The image reader control unit 110 controls the operation of the image reader unit 10 for reading a document (switching on / off of the CCD sensor 14 and the exposure lamp 12, driving control of the scanner motor M2, control of the ADF, etc.). Do. The image signal processing unit 120 includes the CCD sensor 1
4 is converted into a digital signal and subjected to processing such as shading correction, density conversion, and edge emphasis, thereby preventing image quality degradation during reproduction.

The printer control unit 130 includes the CPU unit 13
1, a laser driver 132, a first image memory 133, a second image memory 134, and the like, and controls supply and conveyance of paper in the printer unit 20 and image formation. C
The PU unit 131 receives a detection signal and the like from the SOS sensor 40, and sends control signals to the main motor M1 and the various clutches, thereby performing sheet supply and image formation with good timing.

In addition, the printer control unit 130 starts and stops the polygon motor 24 in accordance with an instruction from the CPU unit 131, and also controls the polygon motor 24 to maintain a constant rotation speed during laser beam scanning. Further, in addition to the rotation of the photosensitive drum 27 and the conveying belts 33 and 35 at a constant speed, the supply of toner to the developing unit 31 and the supply of power to the chargers 30 and 32, exposure scanning based on image data from the image signal processing unit 120 The control of the fixing device 36 and the solenoid 365 is also performed.

The first image memory 133 stores the first image data and the second image memory 13 to be written in the first image forming area Sa.
Reference numeral 4 denotes a multi-port memory for storing second image data to be written in the second image forming area Sb, and having a capacity sufficient to store image data of a document read by the image reader unit 10. In the control unit 100, the image data read by the image reader unit 10 is transmitted from the image signal processing unit 120 to the first image memory 133.
Alternatively, it is sent to the second image memory 134. Then, in each of the image memories 133 and 134, the transmitted image data is stored at each address.

At the time of image formation, the CPU section 131 reads out image data stored in the image memories 133 and 134, and the laser driver 132
Based on the image data read from the third and second image memories 134, the output of the laser diode 21 is controlled to form an electrostatic latent image on the photosensitive drum 27. In the copying machine 1, images of A4 size are formed in parallel when one original is read and a plurality of copies are made on A4 size paper, or when a plurality of originals are continuously read by the ADF. In the case of copying on A4 size paper, in the former case, the same image data is stored in the first image memory 133 and the second image memory 134, and in the latter case, the first image memory 133 and the second image memory are stored. The memory 134 stores different image data.

When an instruction for enlargement or reduction is given, the CPU unit 131 sets the image memory 133,
When reading the image data stored in the memory 134,
By performing interpolation and thinning-out processing using an enlargement / reduction program, an image is read while being enlarged / reduced. [Overview of Control by Printer Control Unit 130] An overview of control by the printer control unit 130 will be described with reference to the flowchart (main routine) of FIG.

First, when the power is turned on, the initialization program initializes various registers in the CPU section 131 and sets the initial mode of each section of the apparatus (S1), generates a clock pulse, and starts timekeeping. (S2). This time measurement is to determine the predetermined time of one cycle of the main routine and manage the entire operation. The subroutines of steps S3 to S5 described below are sequentially called, and after waiting for the end of the required time in step S6, , Step S
Manage the time to return to 2. On the other hand, a predetermined processing time is also assigned to each subroutine, and the time is managed by counting with an internal counter.

After the start of the timing, a cutting selection routine is executed. In this cutting selection routine, as will be described in detail later, whether or not to perform sheet cutting is set, and a selection is made from which of the sheet cassettes 50a and 50b to feed the sheet (S3). Subsequently, a copy operation routine is executed (S4).

In general, formation of a reproduced image on a recording paper is performed by:
It depends on the charge amount of the toner, the surface potential of the photosensitive drum, and the electrostatic force generated by the charge of the transfer charger 32. Since this electrostatic force is affected by the environmental temperature and humidity, the AIDC sensor (automatic image density control) Sensor),
A temperature detection sensor and a humidity detection sensor are provided (each sensor is not shown), and the CPU unit 131 optimally adjusts each condition in the charging charger 30, the developing device 31, and the transfer charger 32 based on these detection signals. I do. The details of these adjustments are known matters that have been made in a conventional copying machine, and thus the details are omitted.

Following the copy operation routine, other routines are executed (S5). Here, a jam process or the like for detecting a paper jam at the time of paper feeding is executed. In the jam processing, the presence or absence of a paper jam is determined based on a detection signal of a jam detection sensor (not shown) arranged in the conveyance path. If it is determined that the paper jam has occurred, image forming is performed. The operation is temporarily stopped, and the occurrence of the jam and its location are displayed on the operation panel 17.

When all the above routines have been completed and a predetermined time has elapsed by the internal timer, the flow returns to step S2 again (S6). [Description of Cutting Selection Routine] FIG.
It is a flowchart which shows the content of a process performed by the cutting selection routine of the said step S3. It should be noted that this is a process performed when the number of instructed copies is plural,
When the number of copies is one, the circular cutter 36 is always used.
Since 3 is not used, the setting of cutting mode non-selection is made.

If the designated paper size mode is not the A4 size (No in S31), the circular cutter 363 is not used, so that the cutting mode non-selection is set (S35). If the paper size mode is designated as A3 size, the setting is made so that A3 size paper is conveyed from the paper cassette 50b and an A3 size equivalent image is formed thereon.

If the designated paper size mode is A4 size (Yes in S31), it is checked whether or not A4 size paper is present in the paper cassette 50a based on a signal from the paper sensor (S32). If it is present (Yes in S32), A4 size paper is conveyed in parallel from the paper cassette 50a, and an image corresponding to A4 size is formed on each of them. Also in this case, the circular cutter 3
Since 63 is not used, the setting of cutting mode non-selection is performed (S35).

If there is no A4 size paper in step S32 (No in S32), it is checked whether A3 size paper exists in the paper cassette 50b based on a signal from the paper sensor (S33). . If it is present (Yes in S33), A3
A sheet of a size is conveyed, and two images of A4 size are set on the sheet. In this case, the A3 size paper is divided into two equal parts using the circular cutter 363.
The cutting mode selection is set (S34).

If there is no A3 size paper in step S33 (No in S33), it is determined that the A4 size and the A3 size are out of paper, and the operation panel 17 displays the out of paper. In this case, cutting mode non-selection is set (S35). In this manner, in the copying machine 1, even when there is no A4 size paper in the paper cassette 50a,
Using A3-size paper in the paper cassette 50b, the same processing as that of forming an image by transporting A4-size paper in parallel is performed.

[Description of Sheet Supply Timing and Image Forming Timing] The printer control unit 130 sets the timing for scanning the first image data and the second image data as follows. The timing to start writing an image in the sub-scanning direction and the timing to convey the paper are set so that the image formed on the photosensitive drum 27 and the conveyed paper coincide at the transfer position.
Here, the interval between the papers that are continuously conveyed is set with a sufficient interval between them so that interference between the papers does not occur.

The writing timing for each line in the main scanning direction is set as follows. Here, a case where images for A4 size are formed in parallel will be described. FIG.
5 is a time chart showing the timing at which the printer control unit 130 instructs the laser driver 132 to write. Image size (A4 size) based on the time when the SOS signal is input from the SOS sensor 40 to the CPU unit 131
, The writing start time Ts1 and the ending time Te1 of the first image are set, and the writing start time Ts2 and the ending time Te2 of the second image are set.

According to this setting, the first and second images are written at the image forming positions Sa and Sb by scanning with laser light as follows. When a laser beam is incident on the SOS sensor 40, the SOS sensor 40 outputs an SOS signal. C
The PU unit 131 receives this and counts the clock. Then, after a lapse of time Ts1 from the reception of the SOS signal, the first SOI signal is issued, and one scan line of the first image data is read from the image memory 137 and sent to the laser driver 132. The laser driver 132 modulates the output of the laser diode 21 and writes this image data in the first image forming area Sa of the photosensitive drum 27. And
After the elapse of the time Te1 from the reception of the SOS signal, the first EO
By issuing the I signal, the writing of one scan line is completed.

After a lapse of time Ts2 from the reception of the SOS signal, a second SOI signal is issued to read one scan line of the second image data from the image memory 137 and send it to the laser driver 132. The laser driver 132 modulates the output of the laser diode 21 and writes this image data in the second image forming area Sa of the photosensitive drum 27. Then, after the elapse of the time Te2 from the reception of the SOS signal, the second
The EOI signal is issued to end the writing.

By repeating such writing of each scanning line, electrostatic latent images of the first and second images are formed on the surface of the photosensitive drum 27. [Description of Adjustment of Image Interval by Printer Control Unit 130]
FIG. 8 shows the first image to be formed and the second image to be formed according to the transport mode.
FIG. 8A is a diagram for explaining how to adjust an interval between images, and FIG. 8A illustrates a case where two A4 size sheets are conveyed in parallel to form a first image and a second image. 8 (b)
Shows a case where an A3-size sheet is conveyed to form the first image and the second image.

In the case of (a), two A
Although a predetermined gap is kept between the four sizes of paper,
This gap is defined as ΔT in terms of the time during which the laser beam scans the surface of the photosensitive drum 27. In addition, the length of the A4 size in the horizontal direction is converted to a scanning time, and is set to W. in this case,
The printer control unit 130 sets the time difference (Ts2−Ts1) between the writing start time Ts1 of the first image and the writing start time Ts2 of the second image to be (W + ΔT). With this setting, the first image and the second image can be formed at the same position on each A4 size sheet.

On the other hand, in the case of (b), the printer control unit 130 determines the time difference (Ts2−Ts) between the writing start time Ts1 of the first image and the writing start time Ts2 of the second image.
1) is set to W. With this setting, when A3 size paper is cut into two A4 size papers, the first image and the second image can be formed at the same position on each A4 size paper. .

[Other Matters] Of course, the contents of the present invention are not limited to the above-described embodiment, and the following can be considered. In the above-described embodiment, an example in which A4 size paper and A3 size paper are used has been described.
When using B4 size paper and B5 size paper, and A4 size paper and A5 size paper, the present invention can be similarly implemented. It is also possible to have a function combining these.

In the copying machine 1, A4 size paper and A
You can copy only on 3 size paper,
It is also possible to adopt a configuration that allows copying on other various sizes of paper. Further, in the above-described embodiment, an example of a copying machine has been described, but the present invention can be similarly applied to an image forming apparatus such as a laser printer.

[0056]

As described above, the image forming apparatus according to the present invention has a first transport mode in which two recording sheets of a predetermined size are transported in parallel while maintaining a predetermined gap, and a size twice as large as the predetermined size. A transport unit for transporting the recording sheet in the second transport mode for transporting the recording sheet, and an image forming unit for forming two images in parallel on the recording sheet transported by the transport unit. Size 2
It is possible to convey a double-sized recording sheet and form two images on it.

Further, when the conveying means conveys the recording sheet in the second conveying mode, the interval between two images formed by the image forming means in parallel is determined by the case where the conveying means conveys the recording sheet in the first conveying mode. Since the image forming interval adjusting means for narrowing the interval between the two images by an amount corresponding to the predetermined interval is provided, the image is located at the same position with respect to the recording sheet as in the first transport mode even in the second transport mode. Is formed.

Further, in the second transport mode, there is provided a cutting means for cutting a recording sheet having a size twice as large as a predetermined size conveyed by the conveying means into two equal parts of a predetermined size after image formation. It is also possible to cut into two recording sheets of a predetermined size by the cutting means.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire configuration of a copying machine according to the present invention.

FIG. 2 is a perspective view showing a configuration of a main part around a photosensitive drum 27 in the copying machine 1;

FIG. 3 is a perspective view showing a sheet cutting mechanism provided in the copying machine 1;

FIG. 4 is a block diagram of a control unit 100.

FIG. 5 is a flowchart illustrating an outline of control of a printer control unit 130;

FIG. 6 is a flowchart showing processing contents of a cutting selection routine of FIG. 5;

FIG. 7 is a block diagram showing the configuration of a printer driver 130 with a laser driver 132
6 is a time chart showing the timing of instructing the writing of the data.

FIG. 8 shows a first image to be formed and a second image to be formed according to a transport mode.
FIG. 4 is a diagram for explaining how to adjust an interval with an image.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier 10 Image reader part 20 Printer part 27 Photoreceptor drum 50a, 50b Paper cassette 100 Control part 130 Printer control part 131 CPU part 133,134 Image memory 361 Fixing roller 362 Discharge roller 363 Circular cutter 364 Engagement roller 365 Solenoid

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location G03G 21/20 G03G 21/00 534 (72) Inventor Kiyoto Tsujihara 2-chome Azuchicho, Chuo-ku, Osaka-shi, Osaka No. 13 Osaka International Building Minolta Co., Ltd. (72) Inventor Hiroshi Otsuka Osaka International Building Minolta Co., Ltd. 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka

Claims (2)

[Claims] 1. A recording apparatus according to claim 1, wherein said recording sheet is conveyed in a first conveying mode in which two recording sheets of a predetermined size are conveyed in parallel while maintaining a predetermined gap and a second conveying mode in which a recording sheet having a size twice as large as said predetermined size is conveyed. Conveying means for conveying; image forming means for forming two images in parallel on a recording sheet conveyed by the conveying means; and forming the image when the conveying means conveys the recording sheet in a second conveying mode. An image forming interval adjusting means for narrowing an interval between two images formed by the means in parallel by an amount corresponding to the predetermined gap from two image intervals when the conveying means conveys a recording sheet in the first conveying mode. An image forming apparatus comprising: 2. A printing apparatus, comprising: a cutting unit that divides a recording sheet having a size twice as large as the predetermined size conveyed by the conveyance unit into an equal size of a predetermined size after image formation in the second conveyance mode. The image forming apparatus according to claim 1, wherein: