JPH11143297A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the improvement of the reliability and extendability of a device by measuring the carrying interval of recording paper., and generating recording paper processing specification data at a recording paper processing specification data controlling part, transmitting them to each image forming controlling part and respectively independently controlling them for the image forming part of each color. SOLUTION: A recording paper detected signal from a paper detection sensor 347 is monitored by a recording paper interval measuring part 205, the attainable timing of the recording paper is detected and distance information or the like indicating carrying intervals between the recording paper is simultaneously measured. Then, recording paper processing specification data 210 corresponding to the recording paper including the distance information are generated by a processing specification data generating means 211a. Then, a processing specification data transmitting means 211c transmits the recording paper processing specification data 210 to image forming control parameter controlling parts 206-209. The image forming control parameter controlling parts 206-209 transmit the recording paper processing specification data 210 to image forming controlling parts 201-204 so that independent control is respectively executed for image forming parts 317-320 of each color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus having a plurality of image forming control units.

[0002]

2. Description of the Related Art FIG. 8 shows an example of an image forming apparatus for continuously performing image forming processing.

[0003] Reference numeral 913 denotes a reader unit including a document reading device and the like. Reference numeral 1 denotes an image forming main unit that performs image forming processing based on data of a document read by the reader unit 913.

Hereinafter, a schematic configuration of the image forming main body 1 will be described.

[0005] Reference numeral 912 denotes a reader control unit for controlling the driving of the reader unit 913 and inputting read data.
Reference numeral 911 denotes an image forming control unit to which data is transferred from the reader control unit 912. 317, 318, 319,
Reference numeral 320 denotes an image forming unit that forms a color image of each color of Y, M, C, and K on the recording paper 10. 347 is
A paper detection sensor detects the recording paper 10 conveyed to the image forming units 317 to 320.

Then, the recording paper 10 is detected by the paper detection sensor 347.
Is detected, the image forming control unit 911 outputs a signal for starting document scanning to the reader control unit 912 and, at the same time, outputs a signal for starting image formation to the image forming units 317 to 320 for each color.

Here, an image formation start signal is sequentially output according to the delay time from the paper detection sensor 347 to the image formation position. Similarly, an image formation end signal is sequentially output after a predetermined time according to the length of the recording paper 10 in the transport direction.

In the case where image formation is continuously performed in the image forming units 317 to 320 of the respective colors, image forming processing is simultaneously performed in parallel on each recording paper 10 based on signals of image formation start and image formation end. Do.

[0009]

In the above-mentioned conventional apparatus, the image forming control section 911 controls the paper detecting sensor 347 and controls the image forming sections 317 to 320 for each color.
The start and end of the image formation are controlled collectively.

However, if it is necessary to change the control of the Y-color image forming unit 317 in accordance with the upgrade of a specific color image forming unit, for example, a unit, the image forming control unit 911 needs to be changed. For this reason, there is a possibility that the control method for the image forming units of other colors that does not need to be changed may be changed, and there is a problem that reliability and expandability are reduced.

Therefore, an object of the present invention is to independently control a plurality of image forming units so that a change in control of a specific image forming unit can be controlled by an image corresponding to the specific image forming unit. An object of the present invention is to provide an image forming apparatus capable of improving reliability and expandability by responding by changing a formation control unit.

[0012]

According to the present invention, there is provided an image forming apparatus for forming image data on recording paper, comprising: image data generating means for generating the image data; and image data forming means for forming the image data on the recording. A plurality of image forming units; a plurality of image forming control units for controlling the plurality of image forming units at predetermined control intervals; a distance information determining unit for determining distance information indicating a transport interval between the recording sheets; Processing specification data generating means for generating processing specification data corresponding to a plurality of recording sheets including distance information, and control interval changing means for changing a control interval of the plurality of image formation control means based on the processing specification data. And a process specification data transfer unit for transferring the process specification data to the plurality of image formation control units, thereby forming an image forming apparatus.

Here, it is possible to further comprise a document reading means for reading the document, and to generate the image data from the read data.

The plurality of image formation control means includes a plurality of control parameter management units for setting control parameters for image formation corresponding to the processing specification data, and controls image formation based on the control parameters. And a plurality of image forming control units.

[0015] The plurality of image forming control means may further include fixing control means for controlling a fixing process at predetermined control intervals.

The fixing control means includes a plurality of control parameter management sections for setting control parameters for the fixing process in accordance with the processing specification data, and a plurality of control parameters for controlling the fixing process based on the control parameters. And a fixing control unit.

The distance information determining means can determine distance information indicating a transport interval between recording papers based on a detection signal of a paper detection sensor.

The distance information determining means can determine distance information indicating a transport interval between recording sheets based on a timing signal of a drive timing of a sheet feeding roller.

The distance information determining means can determine distance information indicating a transport interval between recording sheets based on a timing signal of drive timing of the transport roller.

The distance information determining means can determine distance information indicating a transport interval between recording sheets based on a timing signal of a document scanning timing of the document reading means.

The plurality of image forming means include a photosensitive drum, and can form an image by an electrophotographic method.

The plurality of image forming means include an LED light source,
Alternatively, a laser light source that emits laser light or an inkjet head that ejects ink can be configured as a recording head.

The present invention is also an image processing system for forming an image by transferring image data output from a host device to an image forming apparatus, wherein the image forming apparatus uses the image forming apparatus described above. An image processing system can be configured by forming an image.

[0024]

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

First, a first embodiment will be described with reference to FIGS. The same parts as those in the conventional example (see FIG. 8) are denoted by the same reference numerals.

FIG. 2 is an external view showing a schematic configuration of a digital color copying machine applicable to the present invention. This digital color copying machine is divided into a color reader section 2 as a first roughly classified element and a printer section 3 as a second roughly classified element.

The color reader section 2 reads a document 5 in color from a document feeder 4 attached above it, and outputs a digital color image. The document feeder 4
Instead of attaching a mirror surface pressure plate (not shown) to the upper surface of the color reader unit 2, it may be configured.

The printer section 3 is provided in the image forming main body section 1 and records a digital signal output from the color reader section 2 on a recording paper 10.

[Structure of Color Reader Unit] The schematic structure of the color reader unit 2 will be described.

Reference numeral 301 denotes a platen glass (platen) on which the document 5 is placed. 303 and 304 are original 5
(Halogen lamp or fluorescent lamp).
305 and 306 are condensing mirrors for condensing the light from the light sources 303 and 304 on the surface of the document 5. 307 to 309 are mirrors. Reference numeral 310 denotes a lens that condenses reflected light or projected light from the document 5 on the CCD 101. 311
Is a substrate on which the CCD 101 is mounted. 312 is
An image processing unit that performs image forming processing as shown in FIG. Reference numeral 314 denotes light sources 303 and 304 and the focusing mirror 30.
5 and 306, and a carriage that houses the mirror 307. 315 is a carriage that houses the mirrors 308 and 309. Reference numeral 313 denotes an interface (I / F) unit with another IPU or the like.

FIG. 3 shows a schematic configuration of a portion for performing digital image processing in the image processing section 312.

The light from the light sources 303 and 304 irradiates the original 5 set on the original platen glass 301 and is reflected. The reflected light is guided to the CCD 101 and converted into an electric signal (analog image signal). You.

When the CCD 101 is a color sensor, R, G, and B color filters are arranged in the order of R, G, and B on a one-line CCD. The B filter may be arranged for each line of CCD, or the filter may be formed into a chip or a structure different from the CCD.

Then, the converted electric signal is input to the processing unit 102 of the image processing unit 312. In the processing unit 102, the electric signal is sampled and held (S /
H), the dark level of the analog image signal is clamped to the reference potential, amplified to a predetermined amount, A / D converted, and converted into, for example, R, G, and B 8-bit digital signals and output. .

The converted R, G, B digital signals are subjected to shading correction and black correction in the shading section 103 and then input to the processing section 104. The processing unit 104 executes each process of connection, MTF correction, and document detection. For example, CCD10
If 1 is a 3-line CCD, the splicing process differs in the reading position between the lines, so the delay amount for each line is adjusted according to the reading speed, and the signal timing is adjusted so that the reading positions of the three lines become the same. to correct. In the MTF correction processing, the reading MTF changes depending on the reading speed and the magnification.
Correct the change. The document detection process is performed on the platen glass 3
By scanning the original 5 on the original 01, the original size is recognized.

The digital signal whose read position timing has been corrected is input to a CCD 10 by an input masking unit 105.
1, the light sources 303 and 304 and the condenser mirror 3
05 and 306 are corrected. An output signal from the input masking unit 105 is supplied to an external interface (I /
F) The signal is input to the selector 106 which can be switched with the external I / F signal from the unit 114. The output signal from the input masking unit 105 is input to the color determination unit 117. When the chromatic pixels are continuously detected in the area of 8 × 8 pixels, the color determination unit 117 determines that the document 5 contains a chromatic color, and writes a value corresponding to the chromatic color into an internal register.

The output signal from the selector 106 is input to a processing unit 107 for executing each process of color space compression, background removal, and LOG conversion, and a background removal unit 115. The output signal input to the background removal unit 115 is, after the background removal,
Black character judging section 11 for judging whether the character is a black character in document 5
6 to generate a determination signal indicating whether or not the character is a black character.

On the other hand, in the processing section 107 to which the output signal from the selector 106 has been input, the color space compression determines whether or not the read image signal is within a range that can be reproduced in the printer section 3. If it is within the reproducible range, it is output as it is, otherwise it is corrected so that the image signal falls within the range that can be reproduced by the printer unit 3. Then, a background removal process is performed, and R, G, and B signals are converted into C, M, and Y signals by a LOG conversion process.

The output signal of the processing unit 107 is input to the delay unit 108, and the output timing of the output signal with the determination signal generated by the black character determination unit 116 is adjusted. These two types of signals are input to the moiré removing unit 109 to remove moiré, and are subjected to scaling processing in the scaling process 110 in the main scanning direction.

The signal processed by the scaling unit 110 is U
It is input to the processing unit 111 which executes each process of CR, masking, and reflection of black characters. The C, M, and Y signals are generated by the UCR process to generate C, M, Y, and K signals, corrected by the masking processing unit to the signals at the output of the printer unit 3, and generated by the black character determination unit 116. The judgment signals C, M,
It is fed back to the Y and K signals.

The signal output from the processing unit 111 is subjected to density adjustment by the γ correction unit 112 and then subjected to smoothing or edge processing by the filter unit 113.

The signal processed as described above is output from the color reader unit 2 to the printer unit 3 as an 8-bit multilevel signal. The 8-bit multi-level signal is converted into a binary signal by a binary conversion unit (not shown) of the printer unit 3 (the conversion method is any of dither method, error diffusion method, and an improved error diffusion method). May be).

[Configuration of Printer Unit] The schematic configuration of the printer unit 3 will be described.

In FIG. 2, reference numerals 317 to 320 denote image forming units as image forming means. 317 is an image forming unit for Y color, 318 is an image forming unit for M color, 319 is an image forming unit for C color, and 320 is an image forming unit for K color, and their configurations are the same.

In the image forming units 317 to 320, 34
2 to 345 are photosensitive drums. These photosensitive drums 34
2-345 are LED arrays 410-41 as light sources
The light from 3 forms a latent image on its surface. L
Binary signals converted by the binary conversion unit based on image data are input to the ED arrays 410 to 413, thereby controlling light emission.

321, 324, 327, and 330 charge the surfaces of the photosensitive drums 342 to 345 to a predetermined potential,
This is a primary charger for preparing a latent image. 322,32
5, 328 and 331 are developing units for developing latent images on the photosensitive drums 342 to 345 to form toner images.
These developing units 322, 325, 328 and 331 are provided with sleeves 355 to 3 for applying a developing bias to perform development.
58 are provided. 323, 326, 329, 332
Discharges from the back surface of the transfer belt 333 to transfer the toner images on the photosensitive drums 342 to 345 to the transfer belt 333.
A transfer charger for transferring the image onto the recording paper 10 or the like. In this example, the cleaner is not provided because the transfer efficiency is high. However, the cleaner may be provided.

Next, the image forming process will be described.

The color reader unit 2 outputs an image formation start signal to the printer unit 3 a predetermined time before starting scanning of the original. When the printer unit 3 receives the start signal from the color reader unit 2, the printer unit 3 starts the feeding operation of the recording paper or the like. When switching from the black monochrome mode to the color mode, etc.,
The paper feeding operation is started after a lapse of a switching time for mode switching.

The recording paper 10 and the like stored in the cassettes 340 and 341 are picked up one by one by pickup rollers 338 and 339, and transferred by a transfer belt 333 by paper feed rollers 336 and 337.
Supplied above. The fed recording paper 10 is charged by the adsorption charger 346.

The transfer belt roller 348 is connected to the transfer belt 3
33, and the recording paper 10 is charged in a pair with the attraction charger 346, whereby the transfer belt 333 is charged.
The recording paper 10 is sucked. The leading edge of the recording paper 10 on the transfer belt 333 is detected by the paper detection sensor 347. After that, the recording paper 10
The image forming unit 317 is transported by the transfer belt 333.
In steps 320 to 320, a toner image is formed on the surface of the recording paper in the order of Y, M, C, and K colors.

Then, the recording paper 10 that has passed through the image forming section 320 of K color is separated from the transfer belt 333 after being discharged by the discharging charger 349 to facilitate separation from the transfer belt 333. The peeling charger 350 prevents image disturbance due to peeling discharge when the recording paper 10 is separated from the transfer belt 333.

The recording paper 10 thus separated is
In order to compensate for toner attraction and to prevent image disturbance, the fixing device 33 is charged by the pre-fixing chargers 351 and 352 and then charged.
After the toner image is heat-fixed by the
5 is discharged.

[Configuration of System Control System] Next, the configuration of the system control system will be described with reference to FIG.

A system control section 1000 is provided in the printer section 3 of FIG. This system control unit 10
00 is connected to the image processing unit 312 in the color reader unit 2.

In the system control unit 1000, 2
Reference numerals 01, 202, 203, and 204 denote image forming control units provided for each color of Y, M, C, and K. These image forming control units 201 to 204 include image forming units 317 to 317 for each color.
320.

Reference numerals 206, 207, 208, and 209 denote image forming control parameter management units for each color. The image formation control parameter management units 206 to 209 can transfer data from the recording paper processing specification data 210 and set control parameters to the image formation control units 201 to 204 of each color.

Reference numeral 205 denotes a recording paper interval measuring unit as distance information determining means. This recording paper interval measuring unit 205
The recording paper detection signal from the paper detection sensor 347 is monitored, the arrival timing of the recording paper 10 is detected, and at the same time, the distance information indicating the transport interval between the recording papers 10 is measured.

Reference numeral 211 denotes a recording paper processing specification data management unit. The recording paper processing specification data management unit 211 includes a processing specification data generation unit 211a and a control interval changing unit 21.
1b and processing specification data transfer means 211c.

The processing specification data generating means 211a generates recording paper processing specification data 210 (see FIG. 5 described later) corresponding to the recording paper 10 including the distance information. The control interval changing unit 211b changes the control interval of the image forming control units 201 to 204 based on the recording paper processing specification data 210. The processing specification data transfer unit 211c stores the recording paper processing specification data 210 in the image forming control parameter management unit 20.
6 to 209.

As described above, the recording paper processing specification data management unit 2
Reference numeral 11 manages generation, update, transfer, and the like of the recording paper processing specification data 210 based on input information such as the arrival timing of the recording paper 10 from the recording paper interval measuring unit 205 and the distance from the preceding paper.

Next, the operation of the system control system will be described with reference to FIGS.

FIG. 4 is a flowchart for explaining mainly the control processing in the image forming control units 201 to 204.

In step S10, the image forming control unit 20
Reference numerals 1 to 204 indicate that the image forming control is waiting for a start request. When the system is started, the state transits to this state. Then, when receiving a start request from the recording paper processing specification data management unit 211, the image formation control units 201 to 204 transition to step S20.

In steps S20 to S21, the image forming control units 201 to 204 control the conveyance of the recording paper 10.

In step S20, the paper detection sensor 347
The required time for recording paper conveyance from the sensor position to the image forming positions of the predetermined image forming units 317 to 320 is set in a timer (not shown).

In step S21, when the timer reaches the time-out, the process proceeds to step S30.

In steps S30 to S34, the image forming control units 201 to 204 control the image forming process, and instruct the image processing units 317 to 320 to start the image forming process.

In step S30, the image forming control unit 20
Reference numerals 1 to 204 denote image forming control parameter management units 206 to
209 is instructed to transfer the recording paper processing specification data 210. Image formation control parameter management units 206 to 20
9 is recording paper processing specification data 21 corresponding to the recording paper 10
0 is transferred to the image forming control units 201 to 204.

In step S31, the image forming control unit 20
1 to 204 determine control parameters necessary for image processing from the recording paper processing specification data 210. As a method of determining the control parameter, a different method may be used for each color.

In step S32, the determined control parameters are set in the image processing units 317 to 320, and the start of image forming processing is instructed.

In step S33, the required time until the end processing for the recording paper 10 is determined from the paper size of the recording paper processing specification data 210, and set to a timer (not shown).

In step S34, when the timer reaches the timeout, the process proceeds to step S40.

In steps S40 to S44, the image forming control units 201 to 204 are in a waiting state for the arrival of the next recording sheet, instruct the end of the processing for the recording sheet 10 being processed, and Wait for transport.

In step S40, the image forming control unit 20
Reference numerals 1 to 204 set control parameters for end processing in the image processing units 317 to 320 and instruct the start of processing.

In step S41, the image forming control parameter management unit 206 to 209 is instructed to transfer the recording paper processing specification data 210. The image forming control parameter management units 206 to 209 store the recording paper processing specification data 210 corresponding to the next recording paper 10 in the image forming control units 201 to 20.
Transfer to 4.

In step S42, the presence or absence of the next recording paper 10 is determined from the recording paper processing specification data 210, and if not, the process proceeds to step S10.

In step S43, the required time until the next recording paper 10 arrives is determined from the distance from the preceding paper in the recording paper processing specification data 210, and set to a timer (not shown).

In step S44, when the timer reaches the timeout, the process proceeds to step S30. The image forming control process as described above is repeatedly performed.

FIG. 5 shows an example of the configuration of the recording paper processing specification data 210. The recording paper processing specification data 210 includes ID information 210a, paper size 210b, distance 210c from the previous paper, image size 210d, processing mode 210
e. The value of the paper size 210b is (0,0)
Indicates that there is no subsequent recording paper.

FIG. 6 shows the relationship between the ID information 210a in the recording paper processing specification data 210 and the recording paper 10 being conveyed. Each recording paper 10a, 10b, 10c has a corresponding I
According to the recording paper processing specification data 210 of the D information 210a, the image processing unit 317, the image processing unit 318, the image processing unit 319, and the image processing unit 320 are each performing continuous image formation processing. On the other hand, the recording paper 10d is passing through the paper detection sensor 347, and based on the detection signal from the recording paper interval measuring unit 205, the recording paper processing specification data The specification data 210 is generated.

As described above, the conveyance interval of the recording paper 10 is measured, the recording paper processing specification data management unit 211 generates the recording paper processing specification data 210, and the recording paper processing specification data 210 is stored in each image forming control unit. Since the control is transferred to the image forming units 201 to 204 and the image forming units 317 to 320 of the respective colors are controlled independently of each other, the details of the control of the image forming unit of a specific color can be handled independently for each color. . As a result, it is possible to flexibly respond to a change in the control method, and it is possible to reduce a decrease in reliability due to a specification change.

Next, a second embodiment of the present invention will be described with reference to FIG.
It will be described based on.

In the example described above, the image forming units 317 for each color
To 320 are provided with image forming control units 201 to 204, respectively. In this example, a control processing unit is separately provided for other processing steps for determining a control method using the recording paper processing specification data 210.

FIG. 7 shows an example of a configuration in which a fixing control section 230 and a fixing control parameter management section 231 are provided for the fixing section 334.

The fixing control section 230 performs fixing control on the fixing section 334. Fixing control parameter management unit 231
Can transfer the recording paper processing specification data 210 from the recording paper processing specification data management unit 211, and
The control parameters are set for 30.

As described above, the control processing section is also provided separately for the other processing steps for determining the control method using the recording paper processing specification data 210, so that the control method can be more flexibly changed. , And it is possible to reduce the decrease in reliability due to the specification change.

Although the distance information from the recording paper 10 was measured by monitoring the paper detection sensor 347, the recording paper processing specification data 210 was generated. It is also possible to use. For example, paper feeding such as driving timing of the paper feeding roller 337,
It is also possible to use the transport timing and the document scanning timing of the color reader unit 2.

The image forming control parameter management unit 20
6 to 209 and a fixing control parameter management unit 231
Is for reading and transferring the recording paper processing specification data 210.
209 and 231 may be configured so that the recording paper processing specification data 210 can be updated.

The recording paper processing specification data management unit 211
The image forming control units 201 to 204 and the fixing control unit 230 start state transition in response to a start request from the recording paper interval control unit.
30 are connected to each other, and it is also possible to make a state transition at another obtainable timing. For example, the state transition may be started using the state transition timing of another image formation control unit.

Although the description has been made using the LED light source as the light source, the same control can be performed by using a laser light source or an ink jet head for discharging ink.

Although the document feeder 4 is used as the input image data, the control can also be performed using data transferred from the host computer to the image forming main unit 1, for example. .

[0092]

As described above, according to the present invention,
The recording paper conveyance interval is measured, the recording paper processing specification data management unit generates recording paper processing specification data, and transfers the recording paper processing specification data to each image forming control unit. Since each control is performed independently, it is possible to respond to a change in the control process of a specific process for image formation by changing only the corresponding control unit, thereby improving the reliability and expansion of the apparatus. Performance can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a system control system according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a digital copying machine applicable to the present invention.

FIG. 3 is a block diagram illustrating a configuration of an image processing unit.

FIG. 4 is a flowchart illustrating control of image formation.

FIG. 5 is an explanatory diagram showing recording paper processing specification data.

FIG. 6 is a cross-sectional view illustrating control of image formation.

FIG. 7 is a block diagram showing a configuration of a system control system according to a second embodiment of the present invention.

FIG. 8 is a block diagram showing a conventional example.

[Explanation of symbols]

2, 4 Image data generation means 201 to 204 Image formation control means (image formation control unit) 206 to 209 Image formation control means (image formation control parameter management unit) 205 Distance information determination means 210 Recording paper processing specification data 211a Processing specification data Generating unit 211b Control interval changing unit 211c Processing specification data transfer unit 317 to 320 Image forming unit 230 Fixing control unit (fixing control unit) 231 Fixing control unit (fixing control parameter management unit)

Claims (14)

[Claims] 1. An image forming apparatus that forms image data on a recording sheet, comprising: an image data generating unit that generates the image data; a plurality of image forming units that form the image data on the recording; A plurality of image forming control units for controlling a plurality of image forming units at a predetermined control interval; a distance information determining unit for determining distance information indicating a transport interval between the recording sheets; and a plurality of recording sheets including the distance information Processing specification data generating means for generating processing specification data corresponding to: a control interval changing means for changing a control interval of the plurality of image forming control means based on the processing specification data; and And a processing specification data transfer unit for transferring the image data to the image formation control unit. 2. The image forming apparatus according to claim 1, further comprising a document reading unit for reading a document, wherein the image data is generated from the read data. 3. The image forming control unit includes: a plurality of control parameter management units configured to set control parameters for image formation in accordance with the processing specification data; 3. The image forming apparatus according to claim 1, comprising a plurality of image forming control units for performing control. 4. An image forming apparatus according to claim 1, wherein said plurality of image forming control means further include a fixing control means for controlling a fixing process at a predetermined control interval. . 5. A fixing control unit comprising: a plurality of control parameter management units for setting control parameters for a fixing process in accordance with the process specification data; and controlling the fixing process based on the control parameters. 5. The image forming apparatus according to claim 4, comprising a plurality of fixing control units. 6. The apparatus according to claim 1, wherein said distance information determining means determines distance information indicating a transport interval between recording papers based on a detection signal of a paper detection sensor. Image forming device. 7. The apparatus according to claim 1, wherein said distance information determining means determines distance information indicating a transport interval between recording sheets based on a timing signal of a drive timing of a sheet feed roller. An image forming apparatus according to claim 1. 8. The apparatus according to claim 1, wherein said distance information determining means determines distance information indicating a transport interval between recording sheets based on a timing signal of a drive timing of a transport roller. The image forming apparatus as described in the above. 9. The apparatus according to claim 1, wherein said distance information determining means determines distance information indicating a transport interval between recording sheets based on a timing signal of document scanning timing of said document reading means. An image forming apparatus according to any one of the above. 10. The image forming apparatus according to claim 1, wherein the plurality of image forming units include a photosensitive drum and form an image by an electrophotographic method. 11. The image forming apparatus according to claim 10, wherein the plurality of image forming units include an LED light source. 12. The image forming apparatus according to claim 1, wherein the plurality of image forming units include a laser light source that emits a laser beam.
0. An image forming apparatus according to 13. The image forming apparatus according to claim 10, wherein the plurality of image forming units include an ink jet head that discharges ink. 14. An image processing system for forming an image by transferring image data output from a host device to an image forming apparatus, wherein the image forming apparatus is used as the image forming apparatus. An image processing system, wherein an image is formed using an image forming apparatus.