JPH08286573A - Multiple image forming device - Google Patents

Abstract

PURPOSE: To provide a multiple image forming device constituted so that inconvenience in use caused by the abnormality of only one color is reduced when only one color becomes abnormal and the measures for the abnormality are easily taken. CONSTITUTION: Plural image forming means 21-24 corresponding to the respective prescribed colors are successively arranged along the carrying path of an object to be transferred. By the image forming means 21-24, the images of the respective colors are imparted to the surface of the object to be transferred. By a decision means 31, it is decided whether an action is normal or abnormal for every image forming means. By a correction means 32, the control parameters of the respective image forming means other than the image forming means decided to be abnormal by the decision means 31 are corrected so that the images of the respective colors formed by the respective image forming means are matched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple image forming apparatus such as a tandem type color printer.

[0002]

2. Description of the Related Art A multiple image forming apparatus is known which has a plurality of image forming means for forming an image of a predetermined color, respectively, and makes full use of these to form a multiple image of a plurality of colors on a printing paper or the like. Has been. FIG. 6 exemplifies components of a tandem color printer, which is an embodiment of such a multiple image forming apparatus, relating to image formation. In this figure, reference numeral 100 denotes a transfer belt for conveying printing paper, which is wound around a pair of rollers 100a and 100b. During printing, the rollers 100a and 100b are driven to rotate, and the transfer belt 100 orbits in the direction indicated by the arrow while adsorbing the printing paper. 1
Image forming units 01 to 104 are sequentially arranged along the transfer belt 100, and each of them is composed of a transfer drum or the like. When the printing paper is transported in the direction of the arrow by the transfer belt 100, K (black), Y (yellow), M (magenta), and C are printed by the image forming units 101 to 104.
Images of each color of (cyan) are sequentially applied. As a result,
A multiple image of K, Y, M, and C colors is formed on the printing paper.

In order to form a high quality multiple image in such a multiple image forming apparatus, it goes without saying that each of the image forming means 101 to 104 can form an image of a desired quality. Therefore, it is necessary to keep the state of each image forming unit in the optimum state so that the output images of the respective image forming units are not misaligned, that is, the color shift does not occur. Here, even if each image forming unit is maintained in an optimum state at the time of manufacturing, it is affected by various factors such as a temporal variation factor and a thermal variation factor after that, and therefore, in order to maintain the optimal state. It is necessary to appropriately correct the parameters for controlling each image forming unit according to the situation. Further, when it becomes impossible to provide an image of a predetermined quality due to such correction, it is necessary to notify the user that repair should be performed.

Therefore, in the conventional multiple image forming apparatus, the above-mentioned request is met by performing the following processing when a specific event such as power-on occurs or when the usage time reaches a certain time. Was there.

A. Checking Operation of Each Image Forming Unit While rotating the transfer belt 100, a plurality of image patterns (hereinafter, referred to as samples) having a predetermined shape are formed in each image forming unit 1.
01 to 104 are sequentially formed on the transfer belt 100. Then, C behind each of the image forming means 101 to 104.
The image of each sample formed on the surface of the transfer belt 100 is sequentially captured by the CD sensor 110. The image of each sample thus obtained was evaluated according to a predetermined evaluation item, and as shown in FIG. 7, the sample of which an error occurred for each evaluation item (image width, contrast, ... In FIG. 7) Then, the total number a of these error sample numbers is calculated. Then, when the total a exceeds the predetermined spec A, it is notified that repair is required.

B. Correction of Control Parameter of Each Image Forming Unit If the total a does not exceed the predetermined spec A in the operation check of the above a, the correction operation for obtaining the optimum multiple image is performed. This correction operation is not only the optimization of each image forming unit, but also a correction operation for preventing color misregistration in a multiple image, that is, an operation called registration misregistration correction by a person skilled in the art of the present invention. Including. The specific contents of this registration shift correction are disclosed in detail, for example, in Japanese Patent Laid-Open No. 6-253151.

[0007]

By the way, in the conventional multiple image forming apparatus, since the number of errored samples exceeds the predetermined reference amount as described above, it is regarded as the entire image forming system. There was a problem. (1) Even if only one certain color is abnormal, the entire image forming system is considered to be abnormal, and after that, the misregistration correction is not performed. Therefore, when an abnormality occurs with respect to one color, the image forming means that was normal at that time also gradually deviates from the optimum state. (2) Due to the above-mentioned situation (1), the entire multiplex image forming apparatus cannot be used even if only one color is abnormal. (3) Even if an abnormality occurs, it is not immediately known which image forming means is abnormal, and therefore it takes a lot of repair time for a serviceman. Also, even if the user asks for an explanation of the situation, there is little information that can be grasped at the centralized management center, and the service person has to bring many parts when going to maintenance, which causes downtime and increase in service cost. Was there.

The present invention has been made in view of the above-described circumstances, and when the abnormality of only one color occurs, the inconvenience in use caused by the abnormality is reduced and the countermeasure when the abnormality occurs is dealt with. An object is to provide an easy multiple image forming apparatus.

[0009]

Means for Solving the Problems and Their Actions With respect to the respective functions of the elements constituting the multiple image forming apparatus, the image signal processing means 1, multiple image forming means 2 and control means 3 shown in FIG. It can be divided. here,
The image signal processing means 1 is means for generating image signals corresponding to a plurality of colors. In addition, the multiple image forming unit 2 is configured such that a plurality of image forming units 21 to 24 are sequentially arranged along a conveyance path of a transfer target (not shown), and these image forming units 21 to 24 are the above-mentioned. An image of each color is sequentially applied to the transfer target based on each image signal. The control means 3 plays a role of controlling each of these means. Each of the inventions according to claims 1 to 11 has a main feature in the content of the control performed by the control means 3 for the image signal processing means 1 or the multiple image forming means 2, and each achieves the intended control. Has its own configuration requirements for Since FIG. 1 exemplifies a multiple image forming apparatus provided with all the main constituent features of the inventions according to claims 1 to 11, when focusing on each invention, it is not a constituent feature for each. Will also be shown in FIG. However, in order to facilitate understanding of the position of each invention, it is considered convenient to refer to the elements around the constituent features of each invention. Therefore, referring to FIG. Will be explained.

The invention according to claims 1 to 6 is characterized mainly in the content of control mainly for the multiple image forming means 2.

First, according to the first aspect of the invention, a plurality of image forming means 21 to 24 respectively corresponding to a predetermined color are sequentially arranged along the transfer route of the transferred material. To 24, in the multiplex image forming apparatus for sequentially applying the image of each color to the transferred material, the determining means 31 for determining whether the operation is normal or abnormal for each image forming means.
And a correction unit 32 that corrects the control parameters so that the images of the respective colors formed by the image forming units other than the image forming unit determined to be abnormal by the determining unit are matched. There is.

According to this invention, the determination means 31 determines whether the operation is normal or abnormal for each image forming means, and a detailed determination result regarding the content of the operation abnormality is obtained, so that it is possible to deal with a failure. Will be easier. Further, when it is determined that the image forming unit corresponding to a certain color, for example, the image forming unit 21 is abnormal, the control parameters of the respective image forming units are set so that the output images of the other image forming units 22 to 24 are matched. Since the correction is performed, it is possible to keep the other image forming means in which the abnormality has not occurred in the optimum state even after the abnormality has occurred.

The invention according to claim 2 has a storage means 33 for storing the control parameter of each image forming means each time the determination means 31 makes a determination. Further, the correction unit 32, when the determination unit 31 determines that the specific image forming unit is abnormal, based on the stored contents of the storage unit 33, the control parameter when the image forming unit is finally determined to be normal. Is applied to the image forming means, and for the image forming means other than the image forming means, the control parameters are corrected so that the images of the respective colors output by the respective image forming means are matched.

According to this invention, the image forming means in which an abnormality has occurred is maintained in the state in which the control parameters were normal. Therefore, it is possible to reduce the image quality defect accompanying the transition from the normal state to the abnormal state.

In the invention according to claim 3, the correction means 3
2 is based on a control parameter of a specific image forming unit, for example, the image forming unit 21 among the image forming units 21 to 24, and each image forming unit outputs each image so that the images of the respective colors are aligned. Correct the control parameter. Then, the determining unit 31 determines the specific image forming unit 21.
When it is determined that is abnormal, the control parameters are corrected with reference to the control parameters of the other image forming means.

Many multiple image forming apparatuses correct the control parameter of each image forming means on the basis of one specific color, but the present invention is directed to such an apparatus. In this type of multiple image forming apparatus, if the image forming means corresponding to the reference color is abnormal, the control parameter cannot be corrected. However, in the present invention, in such a case, since the correction is performed with reference to the control parameter of another normal image forming means, such a problem does not occur.

The invention according to claim 4 specifies the function of the judging means 31 in the invention according to claims 1 to 3 described above. That is, the determining means 31 in the invention according to claim 4 causes each of the image forming means 21 to 24 to output an image of a plurality of patterns, and counts the number of patterns in which the output image is abnormal among the respective patterns for each color. However, when the count value for any of the colors exceeds a predetermined reference value, the image forming unit corresponding to that color is determined to be abnormal.

FIG. 2 illustrates the operation contents of the judging means 31. Image forming means 21 to 24 in FIG.
Is to form an image corresponding to each color of K, Y, M, and C, the determining unit 31 causes the image forming units 21 to 24 to form images of a plurality of patterns. Then, it is determined whether or not the output image corresponding to each pattern is normal according to each determination item illustrated in FIG.
The number of patterns in which an abnormality is recognized is obtained for each color of K, Y, M, and C, and the total value b, c, d, and e is obtained. Then, when each total value exceeds the predetermined reference value B, the image forming unit is determined to be abnormal. The predetermined reference value B
May use different values for each color.

The invention according to claim 5 is a notification means (not shown) for notifying the contents of the judgment made by the judgment means 31 to the multiplex image forming apparatus according to any one of claims 1 to 4. Abbreviation) is added. Also, the present invention
Even when the image forming unit is determined to be abnormal, it operates.

According to the present invention, the user can confirm the contents of the judgment, so that it is easy to deal with a failure.
Further, even when there is an abnormality in a certain image forming means, no problem occurs unless the image forming means is used. The present invention allows the use of the device under such circumstances.

The invention according to claim 6 is characterized in that the notifying means notifies the cause of the error instead of or together with the content of the determination.

According to the present invention, not only a notification that the operation is abnormal but also information about the cause of the operation abnormality is obtained, so that it is easy to deal with the failure.

Each of the inventions according to claims 7 to 11 has a main feature in the contents of control for the image signal processing means 1.

First, in the invention according to claim 7, the image signal processing means 1 for generating image signals corresponding to a plurality of colors for forming a multicolor image, and the image signal processing means 1 are sequentially arranged along the conveyance path of the transferred material. A plurality of image forming units 21 to 21 that are arranged and sequentially apply images of respective colors to the transferred object based on the respective image signals.
In the multiplex image forming apparatus including the determining means 24 for determining whether the operation is normal or abnormal for each of the image forming means.
1, the mode setting unit 35 for setting the recording mode of color recording, and when any abnormality of the image forming units is judged by the judging unit, the recording mode is not used by the image forming unit. The image signal processing means 1 is characterized in that the image signal processing means 1 processes the image signal based on the recording mode.

According to this invention, when an abnormality is recognized in the image forming means of a certain color, the recording mode is changed to a mode in which such a color is not used, and the image signal processing means 1 follows the changed recording mode. Form an image signal.

The invention according to claim 8 limits the operation of the mode changing means 35 in the multiplex image forming apparatus according to claim 7, and when a monochromatic recording mode is instructed, the color used in the mode is set. It is characterized in that the recording mode is not changed unless the image forming means corresponding to is abnormal.

If the set recording mode does not use a color for which an abnormality is recognized, no problem will occur, and therefore a multiple image is formed in that recording mode.

According to a ninth aspect of the present invention, in the multiple image forming apparatus according to the seventh aspect, a plurality of image forming units 21 to 2 are provided.
Reference numeral 4 denotes an output of each color image of KYMC, and the mode changing unit 35 sets the recording mode to YMC3 when the image forming unit corresponding to K color is abnormal and the full color recording mode is instructed. It is characterized by changing to the color recording mode depending on the color.

Even if the image forming means 21 corresponding to the K color cannot be used, the K color can be synthesized by mixing the other three YMC colors, so that the image forming means 21 has a failure and the full color recording mode is instructed. In this case, the other image forming means 22 to 23 are used to cope with the color recording mode of three colors of YMC.

According to a tenth aspect of the present invention, in the multiplex image forming apparatus according to the seventh aspect, there is provided first display means (not shown) for displaying a warning when the recording mode is changed by the mode changing means 35. It is characterized by having.

According to this invention, since the change of the recording mode is displayed, it is possible to prevent the user from using the recording mode which is not intended by the user.

According to an eleventh aspect of the present invention, in the multiple image forming apparatus according to the seventh aspect, a unit (not shown) for reading a document and detecting color information of the document, and each of the image forming units 2 are provided.
It is characterized by comprising a second display means for displaying a warning when an image corresponding to the color information cannot be formed due to an abnormality in any one of 1 to 24.

The present invention is applied to a copying machine having a function of automatically setting a recording mode according to the color of a document. According to the present invention, even when an image forming unit corresponding to a certain color cannot be used due to a failure, it is possible to form a multiple image on a document that does not include such a color without causing any problem. .

[0034]

Embodiments of the present invention will be described below with reference to the drawings. A. Configuration of Embodiments The present invention has a plurality of image forming means for applying an image of a predetermined color to a printing paper or the like, and sequentially forms a plurality of images of a predetermined color on the printing paper or the like by these means. It is applied to multiple image forming apparatus. FIG. 3 shows an example of the configuration of a multiple image forming apparatus to which the present invention is applied. In this figure, the parts shown in FIG. 6 above are given the same reference numerals and their explanations are omitted.

In FIG. 3, reference numeral 5 is an image signal processing unit, which serves as the image signal processing means 1 in FIG. 41 to 44 are ROS (Raster Output Scanner) corresponding to each color of K, Y, M and C, 4
Reference numerals 5 to 48 are ROS interfaces. Each ROS
41 to 44 are K generated by the image signal processing unit 5,
Image signals corresponding to the respective colors of Y, M, and C are received via the ROS interfaces 45 to 48, and toner images corresponding to the respective colors are formed on the basis of the respective image signals to form image forming means 101 to 10.
4 is formed on the surface of each developing drum. These toner images are sequentially transferred onto the surface of the printing paper conveyed by the transfer belt 100. 6 is a control panel,
It serves as the above-mentioned notification means and display means. Reference numeral 7 is a control unit and 8 is a correction unit, which serve as the control means 3 in FIG.

B. Operation of the Embodiment When the machine is powered on and printing (or copying) is started, the process proceeds according to the flow shown in FIG. First, the recording mode set by the control panel 6 at that time is taken into the control unit 7 and held in the internal memory (step S101).
Next, it is determined whether or not it is the first print operation after the power is turned on (step S102).

If it is the first printing operation after the power is turned on, the process proceeds from step S102 to step S103, and the registration shift correction cycle is executed prior to the image forming process. Here, the registration shift correction cycle will be described.

First, an image signal forming a specific pattern image for image position detection is output from a memory (not shown) of the image signal processing section 5. Further, the driving of the transfer belt 100 is started. The image signal output from the image signal processing unit 5 is input to the ROSs 41 to 44 corresponding to each color. RO
Based on this image signal, S41 to S44 are based on the image forming means 1
A toner image of a specific pattern is formed on each of the developing drums 01 to 104. Then, this toner image is sequentially transferred onto the transfer belt 100 that moves around. This allows
A specific pattern image of each color is formed over the entire circumference of the transfer belt 100. This specific pattern image is composed of a pattern image for detecting a shift in the moving direction of the transfer belt and a pattern image for detecting a shift in a direction orthogonal to the pattern image.

The transferred specific pattern image is detected by the CCD sensor 110, and the correction unit 8 shifts the specific pattern image of another color with the K specific pattern image as a reference, that is, with the K color as a reference. The misregistration amounts of the three colors are calculated. This registration shift amount is determined by the rotating transfer belt 1
It is shown by a curve having a periodicity of 00 for every one cycle. Further, in the image forming process, the transfer belt 100 is based on a belt reference signal (a signal generated every time a predetermined portion of the transfer belt passes a predetermined reference position) for the printing paper.
It is set so that it can be carried at a fixed position on the peripheral surface of, and when the registration deviation amount of each color is obtained, the average value of the registration deviation amount of each color at each position on one printing sheet is calculated. To be done.

Further, the correction unit 8 is based on this average value.
Corrects the timing of laser exposure performed to obtain an electrostatic latent image corresponding to the formation of a toner image. That is, the operation of shifting the position where the toner image is transferred onto the transfer belt 100 in the appropriate direction by the average value is performed. As a result,
In the image forming process, the toner image of K color is transferred from the image forming unit 101 to the printing paper conveyed by the transfer belt 100, and further conveyed, and the toner image of Y color is transferred from the image forming unit 102, and the image forming unit 103 to M. Color toner image,
When the C color toner image is transferred from the image forming unit 104, the transfer positions of the toner images of the respective colors are corrected so that they are transferred to the same position. Then, the correction value used for the correction (the correction value of the control parameter of each image forming unit obtained based on the above-mentioned registration shift amount) is stored in the memory (corresponding to the storage unit 33 in FIG. 1) in the correction unit 8. It

At the time of the above-mentioned registration shift correction, the failure of the image forming means is also judged for each color. Here, the image output means 10
Whether or not 1 to 104 are abnormal is determined by, for example, the method shown in FIG. That is, the error numbers b, c, d, and e of the output image of the K, Y, M, and C color patterns are obtained, and the determination is made based on whether or not these errors exceed the spec B. Furthermore, even within the same color, it is subdivided into the number of pattern errors that detect the deviation in the moving direction of the transfer belt and the number of pattern errors in the direction orthogonal to it. I do not care. Then, even when the over color is recognized, only the image forming unit corresponding to the color is determined to be abnormal, and the other color misregistration corrections are performed as usual. It should be noted that the same determination is performed when the process control cycle is executed before the image forming process.

As described above, the image forming means 101 to 1
When the registration deviation correction and the failure determination of No. 04 are performed and there is no abnormality in the image forming units 101 to 104, the image forming process is performed as it is in the set recording mode (step S).
105).

On the other hand, if any of the image forming means is abnormal, the process proceeds from step S104 to step S106, and failure information indicating which image forming means cannot be used is notified to the control section 7 of the entire machine. The failure information is held by the control unit 7 (step S10).
6). For the image forming unit determined to be abnormal, the correction value when it is determined to be normal immediately before the occurrence of the abnormality is set to reduce the image quality defect when the abnormality occurs.

Next, whether or not the image forming means of the color required for the image forming processing in the recording mode designated by the control panel 6 (full color, single color mode, etc.) is in a normal state, that is, the recording mode need not be changed. It is determined whether or not (step S107). Here, for example, when the recording mode set by the user is the monochromatic mode of K and the image forming apparatus other than K is determined to have a failure in the correction cycle, the image forming apparatus other than K is not used. Since there is no problem, there is no problem in use. In such cases,
The result of the determination in step S107 is "YES", and the image forming process is executed in the instructed recording mode (step S105).

On the other hand, the determination result of step S107 is "N
In the case of "O", a change is made to the recording mode in which the image forming means in which the abnormality is recognized is not used. In this case, the image signal processing means 5 generates an image signal of each color according to the changed storage mode (step S108).

The following embodiment can be considered as a mode of changing the recording mode. That is, if the recording mode set by the control panel 6 is, for example, full color and it is determined that the image forming means of only K is defective in the registration shift correction cycle, the recording mode is changed to the YMC three-color mode.

Further, when an abnormality occurs in any of the image forming means and the image forming process cannot be performed in the recording mode instructed by the user, "the color cannot be used at present." The recording mode is changed to XXX because it cannot be used. "Is displayed on the control panel. Further, if there is a problem in the operation in the recording mode changed at this time, the operation may be interrupted.

Further, for example, in the case of a copying machine, there is a mode in which a document reading device reads a copy document and automatically determines a color recording mode for the information, but at least one image forming unit has an abnormality. Then, if the image formation processing cannot be performed in the recording mode determined from the read information, "The color cannot be used at the moment." Or "The recording mode cannot be used at this time, so change the recording mode to XXX." Is displayed on the display section of the control panel 6. Further, if there is a problem in the operation in the recording mode changed at this time, the operation may be interrupted.

Even if an abnormality occurs in the image forming means, the operation of the apparatus is not stopped, and the color in which the abnormality has occurred, the error factor, etc. are shown in FIG. The information shown in (including contents) is displayed by an appropriate display means or recorded by a recording means so that the service person or the central control center can grasp the information. By doing so, it is possible to narrow down the failure point in advance and reduce the downtime of the machine. Furthermore, the control panel 6 tells the customer that he can obtain the best print if he does not use the abnormal color.
By displaying a message on the display section of, it is possible to use a document that uses only a specific color without any problem, and downtime is reduced.

In the registration deviation correction cycle described above, if an abnormality is found in the color that serves as the reference for the registration deviation correction, the registration deviation amount cannot be detected based on the color. However, even in this case, it is possible to detect the registration shift amount for colors other than the failed color. In view of this, in the present embodiment, when the flow shown in FIG. 4 is executed, the correction unit 8 subsequently executes the flow shown in FIG.

First, it is judged whether or not the image forming means corresponding to the reference color is judged to be normal (step S20).
1). If this determination result is “YES”, step S2
In step S202, it is determined whether the image forming unit corresponding to a color other than the reference color is normal (step S202). If the determination result is "YES", the control parameters of all the other image forming units are corrected based on the registration shift amounts corresponding to each of them (step S203), and "N".
In the case of "O", the same correction is performed for the normal image forming means (step S204).

On the other hand, when it is determined that the image forming means corresponding to the reference color is abnormal, the process proceeds from step S201 to step S205. In this case, the correction unit 8 changes the reference to another color (step S205). And
Using the changed reference color as a reference, the registration deviation amount for each color in which no abnormality is recognized is obtained (step S206),
Based on the calculated registration shift amount, various control parameters of each image forming unit are corrected (step S207). Note that the registration misregistration correction cycle described above may be executed again after the reference color is changed.

As described above, even when an abnormality occurs in the image forming means corresponding to the reference color, the reference is sequentially changed to another image forming means, and the output image of each normal image forming means is output. The control parameters are corrected so as to be matched without color shift.

[0054]

As described above, according to the present invention, the following effects can be obtained. (1) When an abnormality occurs in a certain image forming unit, the image forming units other than the image forming unit are maintained in the optimum state, so that the minimum image quality impact can be suppressed. (2) Since the presence or absence of abnormality in the image forming means is determined for each color, the customer can easily know the mode in which the image quality defect does not occur, and the down state of the machine can be minimized. (3) The service cost can be reduced by increasing the amount of information for the service.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a configuration of the present invention.

FIG. 2 is a diagram illustrating a method of determining an abnormality in the present invention.

FIG. 3 is a block diagram showing the configuration of a multiplex image forming apparatus according to an embodiment of the present invention.

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

FIG. 5 is a flowchart showing the operation of the embodiment.

FIG. 6 is a diagram illustrating a configuration example of a general multiplex image forming apparatus.

FIG. 7 is a diagram illustrating a method of determining an abnormality in a conventional multiple image forming apparatus.

[Explanation of symbols]

 1 Image Signal Processing Means 2 Multiple Image Forming Means 21-24 Image Forming Means 3 Control Means 31 Judging Means 32 Correcting Means 33 Storage Means 34 Mode Setting Means 35 Mode Changing Means

Claims (11)

[Claims] 1. A plurality of image forming units corresponding to respective predetermined colors are sequentially arranged along a conveyance path of a transfer target, and these image forming units sequentially apply images of respective colors to the transfer target. In the multiple image forming apparatus, each of the image forming units forms a determination unit that determines whether the operation is normal or abnormal, and an image forming unit other than the image forming unit that is determined to be abnormal by the determination unit. A multiplex image forming apparatus comprising: a correction unit that corrects a control parameter so that images of respective colors are matched. 2. A plurality of image forming means each corresponding to a predetermined color are sequentially arranged along a conveyance path of the transferred material, and these image forming means sequentially apply images of each color to the transferred material. In the multiple image forming apparatus, a determination unit that determines whether the operation is normal or abnormal for each of the image forming units, and a storage that stores a control parameter of each of the image forming units each time the determination unit makes a determination And a control parameter when the specific image forming unit is determined to be abnormal by the determining unit and the image forming unit is finally determined to be normal based on the stored content of the storage unit. The image forming means other than the image forming means is provided with a correcting means for correcting the control parameter so that the images of the respective colors output by the respective image forming means are matched. Multiple image forming apparatus as a characteristic. 3. A plurality of image forming means corresponding to respective predetermined colors are sequentially arranged along a conveyance path of the transferred material, and the image of each color is sequentially applied to the transferred material by these image forming means. In the multiple image forming apparatus, each image forming unit has a determination unit for determining whether the operation is normal or abnormal for each image forming unit, and a control parameter of a specific image forming unit among the image forming units as a reference. Is a means for correcting the control parameters of the respective image forming means so that the images of the respective colors outputted by the image forming means are matched, and when the specific image forming means is determined to be abnormal by the determining means, another image forming means And a correction unit that corrects the control parameter based on the control parameter. 4. The determination means causes each of the image forming means to output an image of a plurality of patterns, counts the number of patterns in which an abnormal image is found in the output image of each pattern, and counts each color. The multiple image according to any one of claims 1 to 3, characterized in that when the count value for the color exceeds a predetermined reference value, the image forming means corresponding to the color is determined to be abnormal. Forming equipment. 5. The apparatus according to claim 1, further comprising a notifying unit for notifying the content of the determination made by the determining unit, which operates even when the image forming unit is determined to be abnormal. The multiple image forming apparatus according to claim 1. 6. The multiple image forming apparatus according to claim 5, wherein the notifying unit notifies the cause of the error instead of or together with the content of the determination. 7. An image signal processing means for generating image signals corresponding to a plurality of colors for forming a multicolor image, and an image signal processing means which are sequentially arranged along a transfer path of the transferred material, and are based on the respective image signals. In a multiple image forming apparatus having a plurality of image forming means for sequentially applying images of respective colors to the transferred material, a determining means for determining whether the operation is normal or abnormal for each of the image forming means, and a color recording A mode setting unit that sets a recording mode, and a mode change that changes the recording mode to a recording mode that does not use the image forming unit when an abnormality of any one of the image forming units is determined by the determining unit. Means, wherein the image signal processing means processes an image signal based on the recording mode. 8. The mode changing means, when the monochrome recording mode is designated, does not change the recording mode unless the image forming means corresponding to the color used in the mode is abnormal. Item 7. The multiple image forming apparatus according to Item 7. 9. The plurality of image forming units are each YMC.
An image of each color of K is output, and the mode changing unit performs color recording with three colors of YMC as a recording mode when the image forming unit corresponding to K is abnormal and the full color recording mode is instructed. The multiple image forming apparatus according to claim 7, wherein the mode is changed to a mode. 10. The multiple image forming apparatus according to claim 7, further comprising first display means for displaying a warning when the recording mode is changed by the mode changing means. 11. A warning is displayed when an image corresponding to the color information cannot be formed due to an abnormality in one of the image forming means and the means for reading the original to detect the color information. 8. The multiplex image forming apparatus according to claim 7, further comprising: a second display unit that operates.