JPH07322022A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent an image deviation at the time of synthesizing images by controlling transportation motor speed at the time of forming a second image based on the size of a copy material before and after fixing by means of forming a first image. CONSTITUTION:A size detection sensor 23 constituted of a light-emitting part 21 and a light-receiving part 22 is provided for measuring the size of the copy material P, which is generated by the copy of the picture at a first image forming part A. Then, the size of the auxiliary scanning direction of the copy material P which a feeding roller 12 transports is detected. A controller 18 operates and corrects expansion quantity or contraction quantity on the copy material P based on the size and therefore the transportation speed of the copy material P in a second image-forming part B is corrected. At that time, the transportation motors of the copy materials P in the image forming parts A and B can be set to be equal or the parts can be driven by different motors. Expansion/contraction quantity on a main scanning direction perpendicular to the auxiliary scanning direction is detected, and feeding motor can similarly be corrected/controlled by an operated result. Thus, expansion/contraction quantity in a fixing device 9 can be 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,
In particular, the present invention relates to an image forming apparatus that outputs image information in which a color image and a monochrome image are mixed to a transfer material (recording paper) that is a recording medium.

[0002]

2. Description of the Related Art Conventionally, as means for outputting image information in which a color image and a black and white image are mixed, an electrophotographic image forming apparatus and an image using an ink jet method or a thermal transfer method other than the electrophotographic method are used. There is a forming device.

In the former image forming apparatus, a high-quality output image can be obtained at high speed, but the cost of the apparatus main body is high,
Further, it is difficult to make maintenance free, and it is difficult to use it as a desktop printer. On the other hand, in the case of the latter image forming apparatus, the cost of the apparatus main body is low, and the maintenance is easy, so that it is widely used as a desktop printer. However, when a character image or the like is output, the image quality is not fresh, and particularly when a character is output in black in a color image, character bleeding occurs and the image quality is significantly deteriorated. Further, in the case of the inkjet method, the blackness of characters is also lacking. Further, when used as a desktop printer, it often outputs only a black and white image, and it is necessary to use a special paper specified by the manufacturer, such as coated paper, as the recording paper to be output in a relatively high quality.
Further, the low output speed is unbearable.

Therefore, in order to solve the respective drawbacks when only one type of image forming apparatus is used, it is shown in, for example, JP-A-4-294379, JP-A-5-6127, and JP-A-5-134824. An apparatus combining an electrophotographic method for outputting a black and white image and an inkjet method for outputting a color image has been proposed. in this way,
It was thought that the idea of combining electrophotography and ink jet could solve the aforementioned drawbacks and provide an ideal desktop color printer.

[0005]

However, it has been found that the above-mentioned conventional technique has a serious problem that the writing positions of the black and white image and the color image are deviated on the output image and the image quality is remarkably deteriorated. The occurrence of the shift of the writing position is due to the reason described below.

In the above conventional technique, a black and white image is formed on a transfer material by an electrophotographic method. In electrophotography, as is well known, a black and white image is formed using a toner containing a resin as a main component. In order to permanently fix this toner image on the transfer material, it is necessary to pass the transfer material through a known heating and pressure fixing means. In the heating and pressurizing and fixing means, the toner image on the transfer material is fused and fixed by heat and pressure. Of course, at this time, the transfer material is also heated and pressed.
Moisture in the transfer material evaporates and the transfer material shrinks. The contraction of the transfer material is larger in the transport direction than in the width direction of the transfer material. As a result, when a color image is subsequently formed by the inkjet method, the writing position is lowered (downstream) by the contraction of the transfer material. ), A black-and-white image and a color image are vertically misaligned (conveying direction) on the output image, and the image quality is extremely deteriorated.

This makes it impossible to put into practical use an ideal color print that can be realized by the idea of combining electrophotography and ink jet as described above.

Therefore, an object of the present invention is to provide an image forming apparatus which does not cause image misalignment in an image forming apparatus which outputs a composite image by combining an electrophotographic image forming section and a non-electrophotographic image forming section. To do.

[0009]

In order to achieve the above-mentioned object, the present invention provides a first image forming section for forming a first image and a second image arranged downstream of the first image forming section. An image forming apparatus which has a second image forming unit to be formed, and which forms and outputs one combined image by the first and second images formed by the first and second image forming units. To detect the size of the recording medium before image formation in the first
The dimension detecting means, the second dimension detecting means for detecting the dimension of the recording medium after the image formation in the first image forming section, and the dimension of the recording medium from the dimension of the recording medium detected by the first and second dimension detecting means. Change amount calculating means for calculating and calculating the change amount, and for correcting the dimensional size of the second image in the second image forming section in accordance with the change amount of the dimension calculated by the dimensional change amount calculating means. An image size correction coefficient calculation unit that calculates and calculates a correction coefficient, and controls to correct the size of the second image in the second image forming unit based on the correction coefficient calculated by the image correction coefficient calculation unit. The image forming apparatus is characterized by having image size correction control means for forming a second image.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

(Embodiment 1) First, the configuration common to Embodiments 1 to 3 of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of the image forming apparatus. In FIG. 1, reference numeral A indicates a first image forming portion composed of an electrophotographic apparatus of an electrophotographic system for outputting a black and white image, B indicates a second image forming portion other than the electrophotographic image, and this second image forming portion. Is an inkjet recording device that outputs a full-color image, for example.

First, the structure and operation of the first image forming section will be briefly described with reference to FIG. Reference numeral 1 denotes a photoconductor drum that rotates clockwise in the drawing. Around the photoconductor drum, a primary charger 2 for negatively charging the photoconductor drum 1 and the surface of the photoconductor drum 1 are imaged. A laser exposure device 3 for exposing a latent image to form a latent image, a developing device 4 for reversal development of a latent image formed on the photosensitive drum 1 by using toner as a developer, and a toner on the photosensitive drum 1. A transfer charger 5 for transferring to a transfer material, a charge eliminating needle 6 for erasing the latent image, and a cleaning device 7 for cleaning the photosensitive drum are arranged. Here, as the developing device 4, for example, a developing device by a generally used jumping developing method as shown in JP-A-58-32375 is used.

The image forming apparatus 19 may receive a print instruction signal (hereinafter referred to as a print signal) and a monochrome image and a full-color image signal (mixed image information or monochrome / color separated image information) from an external device: The image forming roller 18 sends a print signal and image data of a monochrome image to the first image forming section A. This allows the paper feed cassette 1
The transfer material P in 1 is extruded by the paper feed roller and is conveyed to the transfer charger 5 via the registration roller 10. Simultaneously with the above operation, the photosensitive drum 1 is charged by the primary charger 2. Then, the photoconductor drum 1 is further irradiated with laser light by the laser exposure device 3, and an electrostatic latent image is formed on the surface thereof. This electrostatic latent image is developed by the toner in the developing device 4. The toner image on the photosensitive drum 1 developed with toner is corona-transferred onto the transfer material P by the transfer charger 5. After that, the transfer material P is conveyed to the fixing device 9 through the conveyance guide 8 and is heated and pressure-fixed there.

Next, the structure and operation of the second image forming section will be briefly described. The transfer material P on which the black-and-white image has been transferred by being processed in the first image forming section of the electrophotographic system enters the second image forming section B. In the second image forming unit, when the transfer material P enters, the feed roller 12 continuously transfers the transfer material P until the front end of the transfer material P passes through the conveyance guide 13 and reaches the paper feed roller 14. . Then, the paper feed roller 14 is
According to the instruction of the color image output timing from the controller 18 of the image forming apparatus 19, the transfer material P is subjected to predetermined transfer control, and is sequentially transferred to the inkjet recording unit 15 line by line. In the inkjet recording unit 15,
Form a color image on the transfer material in addition to a black and white image,
After that, the transfer material P having the final output image formed in this manner is discharged to the paper discharge tray 17 by the paper discharge roller 16.

The transfer motor for transferring the transfer material P of the image forming apparatus 19 may be the same as the first image forming section A and the second image forming section B, or may be driven by a different motor. However, a transfer motor for the transfer material P in the second image forming unit and a motor for controlling the movement of the carriage supporting the inkjet head in the inkjet recording unit 15 (hereinafter referred to as a head feed motor) are not particularly illustrated. , Each is composed of independent motors. Further, although a sensor for carrying control of the transfer material P is provided, the sensor for carrying control is not particularly shown. The respective configurations of the first image forming section A and the second image forming section B up to the above are almost the same as those of the conventional example, but in the present invention, particularly, the size of the transfer material (specifically, (Dimension of Transfer Material after Dimension Change Due to Black and White Image Transfer in First Image Forming Section A)
The sensor 23 (21, 22) for actually measuring is provided. Hereinafter, this sensor will be described.

The sensor 23 (hereinafter referred to as a dimension detection sensor) is a photo-detection type sensor composed of a light emitting portion 21 and a light receiving portion 22, and is in the feeding direction of the transfer material P conveyed from the feeding roller 12 (hereinafter referred to as the feeding direction). , The sub-scanning direction). Then, the controller 18 calculates based on the dimension of the transfer material P detected by the dimension detection sensor 23 to correct the expansion / contraction amount (expansion amount or contraction amount) of the transfer material P of the second image forming unit. The transfer speed of the transfer material P is corrected. In addition, here
For convenience of description, only the expansion / contraction amount of the transfer material P in the sub-scanning direction will be described. However, the expansion / contraction amount in the main scanning direction (the direction perpendicular to the sub scanning direction, that is, the image printing direction on the line) can be detected, and the speed of the head feed motor can be similarly corrected and controlled based on the calculation result. It should be noted that the description thereof is omitted.

Next, the circuit configuration of the image forming apparatus will be described with reference to FIG. FIG. 2 is a schematic block diagram showing the circuit configuration of the controller of the image forming apparatus. In this block diagram, parts not particularly related to the embodiment of the present invention are omitted.

In FIG. 2, reference numeral 40 indicates a main CPU that controls the overall operation of the image forming apparatus 19. In addition,
The controller 18 described in the embodiment is an example for description, and the present invention is not particularly limited to the illustrated circuit configuration. The main CPU 40 uses the IOP (Inpu
t-output Processor) device 42 and I / O (Input / outpu)
t) The print signal and the image signal are transmitted / received to / from the external device through the device 41, and the operation and the image information are transmitted. Then, the image information is expanded as image data of the image by the image processing unit 43 which is connected by the bus (BUS),
It is stored in the cache memory 44, and printing is executed by the image forming unit. On the other hand, in the image forming unit, the main CPU 40 causes the sub CPU 47, the expansion ROM 45, and the RAM 46.
The sub CPU 47 directly controls the operations of the first image forming section A and the second image forming section B.

The image forming apparatus 19 stores in advance information, which has been image-developed by the main CPU 40, in the cache memory 4.
No. 4, and the print is recorded at the timing when the sub CPU 47 issues. That is, when the sub CPU 47 receives a print signal from the main CPU 40, the transfer material P
The main CPU 40 is requested to transfer a black and white image at a desired timing, and a latent image is formed on the photosensitive drum 1 by the laser exposure device. After that, the electrophotographic image forming process is performed as described above. The formation of an electrophotographic image in the first image forming unit A is performed by the sub CPU 47 controlling each control drive circuit of the first image forming unit A to execute image formation. Then, for the transfer material P transferred to the second image forming section, the sub CPU 47 similarly controls each control drive circuit of the second image forming section B to perform image formation as described above.

The image correcting means of the first embodiment described below is included in the program executed by the sub CPU 47, and the normal control operation is performed in the image processing executed by the main CPU 40.

Next, referring to FIG. 3, the control means for the image shift correction of the first embodiment will be described. FIG. 3 shows the first embodiment.
FIG. 9 is a flowchart showing the operation of the above, and shows only the operation of the portion that corrects the deviation between the first image formation and the second image formation of the transfer material P that expands and contracts by the fixing device 9.
Other control parts are omitted.

First, the sub CPU 47 reads and stores the size of the transfer material P before passing through the fixing device 9 (step S50). The dimension detection of the transfer material P before passing through the fixing device 9 is not particularly limited. For example, the transfer material size code designated by the paper feed cassette 11 is read and the transfer material size table is prepared in advance. You may pick up the corresponding transfer material size. Although not shown in particular, the size of the transfer material P may be read by integrating the passage time of the conveyance jam detection sensor provided in the first image forming unit.

Next, in step S51, a black and white image forming process is executed by the already known electrophotographic apparatus described above. When the transfer material is conveyed to the feed roller 12, the process proceeds to step S52, and the dimension of the transfer material P measured by the dimension detection sensor 23 is measured and stored (read and stored).

Next, in step S53, step S5
The dimensional data of the transfer material P stored at 0 and the dimensional data of the transfer material P stored at step S52 are compared and calculated to calculate the expansion / contraction rate of the transfer material P. Further, based on the calculated expansion / contraction rate, A correction constant for correcting the expansion / contraction amount of the image formed in the first image forming unit by correcting and controlling the conveyance speed of the transfer material P in the second image forming unit is calculated. A specific example will be described below. It is assumed that the transfer material transport motor used in the second image forming unit is, for example, a pulse motor, and its exciting pulse is 600 PPS. The size of the transfer material is "300 mm" before passing through the fixing device.
If, after passing through the fixing device, it shrinks to '297 mm', {(300 mm-297 mm) / 300 mm} = 1%
.. (Expansion / contraction rate of transfer material P) {600 pps- (600 pps × 1%)} = 594 p
ps ··· (corrected rotation of the carry motor) is calculated.

Next, in step S54, for example, if the expansion / contraction rate of the transfer material P is 0%, the number of corrections of the conveyance motor remains 600 PPS and the pulse width is set in advance for output control of the excitation pulse. The motor value is 1/600 = 1.
Set to 67 mS. In addition, as described above, the transfer material P
When the expansion / contraction rate of 1 is 1%, the pulse width setting timer value that controls the excitation pulse output in advance is 1/594 = 1.68m.
Set to S. Finally, in step S55, as described above, the color image forming process by the inkjet device is performed normally.

As described above, in the second image forming section, the transport speed of the transfer material P is controlled to be faster or slower by an amount corresponding to the amount of expansion and contraction of the fixing device 9. The amount of expansion and contraction of the image is corrected.

That is, for example, even if the transfer material is contracted by 1% by the fixing device, the conveyance speed of the transfer material in the second image forming section is controlled by 1% faster corresponding to the contraction amount. Since the image in 1) is also shrunk by 1%, the image shift between the first image forming unit and the second image forming unit is automatically corrected. Even if the transfer material is stretched by the fixing device,
Similarly, if the dimensional ratio before and after the fixing device is calculated and the excitation pulse width of the transport motor is delayed in accordance with the expansion / contraction rate of the transfer material P, the image shift between the first image forming unit and the second image forming unit will occur. It will be corrected automatically.

As described above, in the first embodiment, the expansion / contraction amount of the transfer material is detected, and the change ratio is corrected by the speed of the carry motor, so that the first image forming portion and the second image forming portion are corrected. Is to automatically correct the deviation of the image. Also,
For convenience of explanation, only the correction of the image shift in the sub-scanning direction has been described.
It goes without saying that correction control can be performed in the same manner. That is, for example, the CCD sensor detects the amount of expansion and contraction in the main scanning direction before and after the fixing device, the motor correction ratio is calculated by the same calculation, and instead of the change ratio, the speed of the conveyance motor is corrected and controlled. The speed of the head feed motor in the inkjet recording unit 15 may be corrected and controlled by the change ratio of the transfer material. Furthermore, the correction control may be performed simultaneously in the main scanning direction and the sub scanning direction, or may be performed in only one of them. The means for measuring and detecting the expansion / contraction amount of the transfer material is not particularly limited.

(Second Embodiment) Next, a second embodiment will be described. In the above-described first embodiment, the change amount of the image size caused by the expansion and contraction of the transfer material P itself caused by the image recorded in the first image forming section A passing through the fixing device is set to the second value.
In the image forming unit B, the image size is matched by correcting the speed of the carry motor at a ratio corresponding to the expansion / contraction amount of the transfer material P itself. On the other hand, the second embodiment described below is similar to the first embodiment in that the expansion / contraction amount of the transfer material P itself is detected. However, in the second embodiment, after that, by referring to the image resolution in the second image forming unit, how many lines the expansion / contraction amount of the transfer material P corresponds to the movement in the sub-scanning direction in the second image forming unit B. Is calculated, and the calculated number of lines is selected as a line having no image information, and the conveyance distance of the transfer material P in a portion having no image information is rotated by a specified number of lines with respect to a predetermined distance. The image sizes recorded in the second image forming unit B are matched by thinning out or interpolating the time. In the second embodiment, as in the first embodiment, the correction only in the sub-scanning direction will be described for the sake of convenience of explanation. However, in the main-scanning direction, the corresponding number of lines is similarly thinned out from the whole image or interpolated. The image size can be matched by the correction.

In order to easily understand the contents of the second embodiment, the ink jet device forming the second image forming section B will be briefly described in advance. An inkjet device generally belongs to a serial printer, and unlike a page printer such as a laser beam printer,
The transferred image data is sequentially recorded. That is, the inkjet recording unit called a head scans the main scanning direction once to form a one-line image. In recent years, an array head is one that scans (scans) in the main scanning direction to form an image of several lines at the same time, and one that scans several lines in the main scanning direction to form an image of one line in combination. However, in order to facilitate the description, the second embodiment will be described based on an example in which one scan is performed in the main scanning direction to form an image of one line.

Further, when there is no image data on one line, the serial printer only carries the print paper without scanning the head by a line skip command issued to the printer device. In other words, the head is scanned with respect to the line of the part where the image is recorded, but the part where the image is not recorded is continuously scanned with the head until the line of the part where the image is recorded next. The print paper is conveyed to.

In the second embodiment, the sub CPU 47 stepwise operates the carrying motor for carrying the transfer material P line by line according to the image data from the main CPU 40. For ease of explanation, it is assumed here that the number of step pulses of the motor that conveys one line of the image corresponds to 1: 1. That is, it is assumed that one pulse is excited by the carry motor and the image forming line advances one line.

Therefore, the sub CPU 47 sequentially operates the ink jet recording section 15 while receiving one line image data, and outputs one exciting pulse to the carry motor when the next line image data is received. Also, in case of line skip due to no image data,
The excitation pulse is output to the carry motor by the number designated by the main CPU 40.

The operation performed by the sub CPU 47 in the second embodiment will be outlined in advance. As in the first embodiment, the expansion / contraction amount of the transfer material P detected by the dimension detection sensor 23 is calculated. After that, in the second embodiment, the number of lines corresponding to the amount of expansion and contraction is calculated, and correction is performed to the number instructed by the main CPU 40 at the time of line skip due to no image data.
The image size to be recorded is matched by performing thinning correction or interpolation correction on the corresponding line number from the entire image.

Next, the specific control means will be described with reference to the flow chart of FIG. FIG. 4 is a flowchart showing the operation of the second embodiment, and the same operation as that of the first embodiment is indicated by the same reference numeral, and the description thereof is omitted.

Similar to the first embodiment, when the expansion / contraction amount of the transfer material P can be detected in step S52, the process proceeds to step S56, and in step S56, the expansion / contraction amount of the transfer material P is determined by how many lines of image formation. The number of lines is calculated by calculating whether they correspond. It is now assumed that the shrinkage dimension of the transfer material P calculated in the same manner as in Example 1 is "0.5 mm", and the ink jet recording unit 15 in the second image forming unit B is "360 dp".
It is assumed that the resolution i'is used.

In this case, (360 dpi / 25.4 mm
/Inch)×0.5 mm = 7 lines (thinning line number setting value) is executed to calculate the number of lines corresponding to the shrinkage. Since the transfer material P is contracted, it is only necessary to thin out the image by 7 lines from the entire image formation.
At this time, by thinning out the lines that are white images, image loss can be prevented. On the other hand, when the transfer material P is stretched by “0.5 mm”, the image may be stretched by interpolating the image by 7 lines from the entire image formation.

Next, in step S57, when the calculated thinning line number is thinned out from which part of the entire image or the calculated interpolation line number is interpolated to which part of the entire image in step S57. Determine the allocation of. Here, whether or not the expansion and contraction of the transfer material P is uniform,
Alternatively, for example, conditions such as logarithmic expansion and contraction are tabulated, and although not particularly shown,
The distribution from thinning / interpolation lines is determined by an instruction from an external device or a key input of the image forming apparatus 19. The lines to be thinned / interpolated are strictly white image lines.

Next, in step S58, the recording process in the second image forming section B described in the first embodiment is executed in step S58. However, it differs from Example 1 in the following points. That is, a predetermined number of lines are thinned out / interpolated at the time of line skipping due to the absence of image data occurring in the lines in the portion distributed in step S57. For example, as a specific example, when the image is formed from the 0th line to the 100th line and then the image is formed again from the 160th line, 10
Assuming that 3 lines are thinned out between the 1st line and the 160th line, the main CPU 4
Drive the transport motor with the line transport indicated by 0, and
From the first line to the 160th line, the number of line conveyances designated by the main CPU 40, that is, the conveyance position of 60 lines is corrected, and the conveyance motor is actually driven by 57 lines conveyance. This means that the white images for three lines have been thinned out. That is, as compared with the case of the first embodiment in which the transfer speed of the transfer material P is changed, in the second embodiment, the transfer speed of the transfer material P is not changed, but the feed amount of the transfer material P (the transfer distance of the transfer motor is 1 line. The amount of line feed per unit) is thinned / interpolated and corrected.

Therefore, as is clear from the example shown in FIG. 5 for explaining the thinning correction example, for example, by thinning out the white image of 60 lines by 3 lines and replacing it by 57 lines,
The entire image is shrunk and recorded by the first image forming unit, then shrunk by the fixing device and corrected by the amount of the first image forming unit and the second image forming unit.
The image dimensions can be matched between the image forming units.

The thinning / interpolation of the white lines in the sub-scanning direction as described above is carried out by the transport motor of the second image forming unit B after the thinning / interpolation distribution is determined by the sub CPU 47. Regarding the main scanning direction, the sub CPU 47 instructs the main CPU 40 to transfer the determined thinning / interpolation distribution, and executes thinning and interpolation of white lines in the main scanning direction during image development of the second image forming unit. , Just print it.

(Third Embodiment) Next, a third embodiment will be described. In the first embodiment, the transfer material P generated due to the image recorded in the first image forming section A passing through the fixing device 9 is generated.
In the second image forming section B, the change amount of the image size caused by the expansion / contraction of the transfer material P itself is corrected by the ratio corresponding to the expansion / contraction amount of the transfer material P to match the image size. . On the other hand, in the second embodiment, the expansion / contraction amount of the transfer material P itself is detected, the image resolution of the second image forming unit B is referred to, and the expansion / contraction amount corresponds to how many lines for the second image forming unit B. This is calculated, and the corresponding line number is thinned out or interpolated from the entire image to match the image size recorded in the second image forming unit B.

On the other hand, in the third embodiment, the expansion / contraction amount of the transfer material P itself is detected, the expansion / contraction ratio is calculated, and the calculation result is instructed to the main CPU 40 for image development, whereby image processing is performed. By the image editing function of the section 43,
The size of the image printed by the second image forming unit B is reduced / enlarged to match the size of the image recorded by the second image forming unit B. The image forming unit 43 referred to in the third exemplary embodiment.
The reduction / enlargement function of the image information itself, which is one of the image editing functions possessed by, is not particularly limited in the present invention and is the same as the image editing function possessed by a general recording apparatus, and therefore the description will be omitted. Omit it.

Next, referring to FIG. 6, the control means for the image shift correction of the third embodiment will be described. FIG. 6 shows the third embodiment.
It is a flowchart figure which shows operation | movement. First, Sub C
The PU 47 reads and stores the size of the transfer material P before passing through the fixing device 9 (step S50). The size detection of the transfer material P before passing through the fixing device 9 is not particularly limited as in the first embodiment. Then, in step S51, a monochrome image forming process by a known electrophotographic apparatus is executed. When the transfer material is conveyed to the feed roller 12, the process proceeds to step S52, and in this step S52,
The dimension of the transfer material P is actually measured and recorded by the dimension detection sensor 23. Next, in step S53, step S50
The dimension data of the transfer material P stored in step S52 and the dimension data of the transfer material P stored in step S52 are compared and calculated to obtain the transfer material P.
The expansion / contraction rate of is calculated.

Then, in step S59, what percentage of the image size to be recorded in the second image forming unit B is to be reduced or enlarged is calculated, and the setting value request is set in the main CPU 40. The main CPU 40 that receives the request causes the image processing unit 43 to edit the image development data, although not particularly limited thereto.

A specific example of calculation in step S59 will be described below. Assuming that the size of the transfer material P before passing through the fixing device 9 is “279 mm”, the read size by the size detection sensor 23 in step S52 is “270.6 m”.
If m ', then {(279 mm-270.6 mm) / 279 mm} = 3
% ... (Expansion / contraction rate of the transfer material P) 100% -3% = 97% ... (Image reduction request setting value) is calculated.

Then, a 97% image data transfer request is executed to the main CPU 40. As a result, in step S60, the color image forming process by the inkjet device is normally performed by the already known image editing function such as reduction / enlargement of the image.

As described above, the image of the transfer material P is recorded by reducing / enlarging the image size in the second image forming unit corresponding to the amount of expansion and contraction by the fixing device 9 in the first image forming unit. , The expansion / contraction amount of the first image is corrected.

The characteristic of the third embodiment is that the second image is transferred depending on the expansion and contraction of the transfer material P by the fixing device 9 of the first image forming section A.
The calculation of the set value for correcting the image size recorded in the image forming unit B and the instruction of the correction value are included. That is, the image processing for actually executing the image correction as in the third embodiment is not particularly limited. Therefore, with the correction coefficient designated as an example of the image editing function, the image is reduced / reduced.
Although the enlargement is executed, in addition, the expanded image is expanded by recording the expanded image in the image processing unit 43 by thinning / interpolating the arrangement of the image itself according to the designated correction coefficient. The shrinkage may be corrected.

[0050]

As described above, according to the present invention, in the image forming apparatus for outputting the composite image by combining the electrophotographic image forming section and the image forming section other than the electrophotographic type arranged downstream thereof, Based on the ratio of the size of the transfer material (recording paper) before fixing in the electrophotographic image forming section to the size of the transfer material after fixing, the transfer material is used when the image is formed in the image forming section other than the electrophotographic method. Speed of the transport motor for feeding paper (or the speed of the transport motor for the image recording member)
Is controlled, or line feeding of the transfer material is thinned, interpolation is performed, or image information is reduced / enlarged, so that an image forming apparatus that does not cause image shift can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an image forming apparatus.

FIG. 2 is a schematic block diagram showing a circuit configuration of a controller of the image forming apparatus.

FIG. 3 is a flowchart showing the control operation of the first embodiment.

FIG. 4 is a flowchart showing a control operation of the second embodiment.

FIG. 5 is a diagram for explaining an example of thinning correction.

FIG. 6 is a flowchart showing a control operation of the third embodiment.

[Explanation of symbols]

 A first image forming section (electrophotographic image forming section) B second image forming section (image forming section other than electrophotographic type) 1 photoconductor drum 2 primary charger 3 laser exposure device 4 developing device 5 transfer charger 6 Static Elimination Needle 7 Cleaning Device 8 Conveying Guide 9 Fixing Device 10 Registration Roller 11 Paper Feed Cassette 12 Feeding Roller 13 Conveying Guide 14 Paper Feeding Roller 15 Inkjet Recording Section 16 Paper Ejection Roller 17 Paper Ejection Tray 18 Controller 19 Image Forming Device 20 Paper Feeding Roller 21 Light emitting unit 22 Light receiving unit 23 Dimension detection sensor 40 Main CPU 41 I / O 42 IOP 43 Image processing unit 44 Cache memory 45 Expansion ROM 46 Expansion RAM 47 Sub CPU

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location G03G 15/22 105 B 15/36 (72) Inventor Naohiro Nakane 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Canon Inc. (72) Kenji Muto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Noboru Yukimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yasushi Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yukihiro Ozeki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Katsuhiro Sakazawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yasunori Kono 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc.

Claims (10)

[Claims] 1. A first image forming unit for forming a first image, and a second image forming unit arranged downstream of the first image forming unit for forming a second image, and having first and second images. In an image forming apparatus that forms and outputs one combined image by the first and second images formed by the forming unit, a first size detection that detects the size of the recording medium before the image formation by the first image forming unit Means, a second dimension detecting means for detecting the dimension of the recording medium after the image formation in the first image forming section, and a change of the dimension of the recording medium from the dimension of the recording medium detected by the first and second dimension detecting means. And a correction coefficient for correcting the dimensional size of the second image in the second image forming unit in accordance with the dimensional change calculated by the dimensional change calculating means. Image dimension correction coefficient calculator A second step in the second image forming section based on the correction coefficient calculated by the image correction coefficient calculation means.
An image forming apparatus, comprising image size correction control means for controlling the size of an image to form a second image. 2. The image forming apparatus according to claim 1,
The dimensional change amount calculating means calculates the expansion / contraction rate of the dimension of the recording medium from the dimension of the recording medium detected by the first dimension detecting means and the dimension of the recording medium detected by the second dimension detecting means, and the image The dimension correction coefficient calculation means calculates at least one correction coefficient of the conveyance speed of the recording medium and the conveyance speed of the image recording member in the second image forming unit based on the expansion / contraction rate calculated by the dimension change calculation means. And the image size correction control means controls at least one of the transport speed of the recording medium and the transport speed of the image recording member based on the correction coefficient calculated by the image size correction coefficient calculation means. An image forming apparatus characterized by. 3. The image forming apparatus according to claim 1,
The dimensional change calculation unit calculates a difference or increment in the size of the recording medium from the size of the recording medium detected by the first size detecting unit and the size of the recording medium detected by the second size detecting unit, and the image The dimension correction coefficient calculation means, based on the difference or increment calculated by the dimension change amount calculation means,
The number of lines in the conveying direction of the recording medium in the second image forming unit is calculated, or the number of interpolation lines is calculated, and the image size correction control unit calculates the number of lines or interpolation lines calculated by the image size correction coefficient calculation unit. An image forming apparatus that controls the conveyance of the recording medium based on the above. 4. The image forming apparatus according to claim 3,
An image forming apparatus, wherein a white image is applied to the thinning or interpolation line. 5. The image forming apparatus according to claim 3,
An image forming apparatus further comprising means for determining a portion on an image where the thinning-out or interpolation line is performed. 6. The image forming apparatus according to claim 1,
The dimensional change amount calculating means calculates the expansion / contraction rate of the dimension of the recording medium from the dimension of the recording medium detected by the first dimension detecting means and the dimension of the recording medium detected by the second dimension detecting means, and the image The dimension correction coefficient calculation means calculates the reduction or enlargement rate of the image information in the second image forming section based on the expansion / contraction rate calculated by the dimension change amount calculation means.
An image forming apparatus, wherein the image size correction control means records on a recording medium with an image size reduced or expanded based on the reduction or expansion rate of the image information calculated by the image size correction coefficient calculation means. 7. The image forming apparatus according to claim 6,
An image forming apparatus, wherein the image information is reduced or enlarged by an image editing function. 8. The image forming apparatus according to claim 1,
An image forming apparatus comprising at least one of a dimensional change calculation unit, an image size correction coefficient calculation unit, and an image size correction control unit described in claim 2, claim 3, and claim 6, respectively. 9. The image forming apparatus according to claim 1, wherein the first image forming unit is an electrophotographic image forming unit, and the second image forming unit is an electrophotographic image forming unit. An image forming apparatus other than the above. 10. The image forming apparatus according to claim 9, wherein the electrophotographic image forming unit forms a black-and-white image, and the non-electrophotographic image forming unit forms a color image. apparatus.