JP2000047447A - Image forming device and regulating method of image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the shortening of the execution time (print impossible time) of density correction control processing and image registration correction processing to improve the usability. SOLUTION: In an image forming device for superposing a plurality of color component images formed by developers having different colors over an intermediate transfer body by one image forming device or a plurality of thereof according to a plurality of supplied color component signals to form a multicolor image, a density detecting sensor 5 detects the image density of a patch pattern formed on the intermediate transfer body, and a CPU 1017 controls on the basis of the change of the image density of the prescribed pattern detected by the density detecting sensor 5, the image forming timing and image forming density by the image forming parts for every color component, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a plurality of color component images formed by one or more image forming units with different color developers in accordance with a plurality of supplied color component signals on an image carrier. The present invention relates to an image forming apparatus for forming a multi-color image by superimposing a multi-color image on an image, and a method for adjusting the image forming apparatus.

[0002]

2. Description of the Related Art An apparatus of this type has conventionally been provided with a plurality of image forming units for irradiating a photoreceptor with laser light and developing an electrostatic latent image on the photoreceptor by an electrophotographic process. Is superimposedly transferred onto the intermediate transfer body, and while the recording paper is sequentially conveyed to the image forming portion of the intermediate transfer body by the transfer belt,
2. Description of the Related Art An image forming apparatus that transfers a color image onto recording paper to obtain a color image is known.

When an image forming apparatus of this type is used, an electrostatic latent image is formed on each photosensitive drum due to a mechanical mounting error of each photosensitive drum, and when an electrostatic latent image is transferred onto a recording paper on a transfer belt, an image of each color is formed. There was a problem that registration could not be performed.

For this reason, conventionally, a registration correction pattern image formed on an intermediate transfer member or a transfer belt from each photosensitive drum is read by a CCD image sensor or the like, and registration deviation on the photosensitive drum corresponding to each color is detected. Has been detected, an image signal to be recorded is electrically corrected, and further, a reflection mirror provided in the laser beam optical path is driven to correct the optical path length change or the optical path change.

Further, in the above-described conventional color image forming apparatus, if the image density fluctuates due to various conditions such as the environment in which the apparatus is used, the number of prints, etc., the original correct color tone cannot be obtained. Therefore, conventionally, in order to determine the state of an image at the time of image formation, a toner image (hereinafter, referred to as a patch) for each color density detection is experimentally formed on a photosensitive drum or an image carrier (intermediate transfer body). The density is automatically detected by a density detection sensor such as an optical sensor, and the detection result is fed back to the image forming conditions such as the exposure amount and the developing bias, and the density is controlled to form an original color image, and a stable image is formed. Was getting.

Hereinafter, an example of a density correction control process of a conventional image forming apparatus will be described.

First, a plurality of patch patterns of different densities are formed on the photosensitive drums of each color while sequentially changing the developing bias, and are transferred to an intermediate transfer member. Each patch pattern is irradiated with infrared light from the irradiation part of the density detection sensor, and the reflected scattered light is similarly measured by the light receiving part of the density detection sensor and is taken into the CPU or the like. In the CPU, the sensor output voltage is converted into a density, the density of the patch image is associated with each developing bias when the control is executed, a developing bias for obtaining a desired density is calculated backward, and the developing bias is calculated as the corresponding value. Stored in memory as the optimal development bias at the time,
It is used until the next density correction control process. Thus, the optimum developing bias voltage at that time was set.

[0008]

However, the above-described registration correction processing and density correction control processing require execution of a special sequence dedicated to each, and during that time, it is impossible to perform a printing operation. there were. As a result, the user is inconvenienced,
There is a problem that the usability is reduced.

In the above-described registration correction processing, the formed registration correction pattern image is detected by a CCD or the like, and in the density correction control processing, the formed patch image is detected by an optical sensor or the like. However, it is necessary to provide a CCD image sensor and an optical sensor, which raises the problem of increasing the price of the apparatus.

Further, in the above-described registration correction processing, a pattern image for registration correction is formed on an intermediate transfer member or the like, and in the density correction control processing, a patch pattern is formed on the intermediate transfer member or the like. In these sequences other than the above, a large amount of toner is used, and the toner is wasted. In addition, the registration correction pattern image and the patch pattern contaminate the photosensitive member and the intermediate transfer member, and the photosensitive member and the intermediate transfer member. There is also a problem that the life of the transfer body or the like is shortened.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the first to ninth inventions according to the present invention to provide an image processing apparatus which performs one or more color component signals according to a plurality of supplied color component signals. An image forming apparatus for forming a multi-color image by superimposing a plurality of color component images formed by different color developers by one or more image forming units on an image carrier; A predetermined color pattern is formed on the image carrier, an image density of the predetermined color pattern formed on the image carrier is detected, and based on a change in the detected image density of the predetermined pattern. By controlling the image formation timing and the image formation density by the one or more image forming units for each color component, a predetermined color pattern for detecting the image formation density formed on the image carrier is controlled. Based on the detection result To perform both the image registration correction process and the density correction control process, thereby shortening the execution time of the density correction control process and the image registration process (impossible printing time) to improve usability. Image forming apparatus and image forming apparatus capable of reducing the number of times of image formation on the image carrier during the adjustment process, reducing toner consumption during the adjustment process, and minimizing contamination of the image carrier. An object of the present invention is to provide a method for adjusting a forming apparatus.

[0012]

According to a first aspect of the present invention, there is provided one or more image forming units (photosensitive drums 1a to 1d, lasers shown in FIG. 1) corresponding to a plurality of supplied color component signals. Scanner units 2a to 2d, developing units 3a to 3d)
The image forming density is detected in an image forming apparatus that forms a multi-color image by superimposing a plurality of color component images formed by developers of different colors on an image carrier (the intermediate transfer member 4 shown in FIG. 1). A first control unit (FIG. 2) for controlling the one or more image forming units to form a predetermined color pattern (the patch pattern 105 shown in FIGS. 3 to 5) for forming the image on the image carrier. A density correction control processing patch pattern forming circuit), detecting means (a density detecting sensor 5 shown in FIG. 1) for detecting the image density of the predetermined color pattern formed on the image carrier, and the detecting means The image forming timing and the image forming density by the one or more image forming units are respectively set for each color component based on the change in the image density of the predetermined pattern detected by Gosuru second control means is one having a (CPU 1017 shown in FIG. 2 is controlled based on the program stored in the ROM 1030).

According to a second aspect of the present invention, the predetermined color pattern (the patch pattern 105 shown in FIGS. 3 to 5) is used.
Is a patch pattern (color component patch image 40 shown in (a) of FIG. 5) in which each color component image whose tip is emphasized (developed at the maximum density) in parallel with the moving direction of the image carrier is continuously formed.
1Y, 401M, 401C, 401Bk, color leading edges 402Y, 402M, 402C, 402Bk) are continuously formed at different densities in parallel with the image carrier moving direction (patch pattern 105 shown in FIG. 4).
A, 105B,...).

In a third aspect according to the present invention, the second control means (CPU 1017 shown in FIG. 2) controls the emphasis based on a change in image density of the predetermined pattern detected by the detection means. The leading end of each color component image (FIG. 6)
The output voltages 602Y, 602M,
602C, 602Bk), and controls the timing of supplying each color component signal to the one or more image forming units for each color component signal in accordance with the detection result.

According to a fourth aspect of the present invention, the second control means includes means for changing a change in image density of the predetermined pattern detected by the detection means (patch pattern 1 shown in FIG. 4).
The output voltages 601Y, 601M, 601C, and 60 of the color component patch images shown in FIG.
1Bk), the developing bias voltage to the one or more image forming units is controlled for each color.

According to a fifth aspect of the present invention, the detecting means is an infrared light reflection type surface reflectance measuring sensor (a density detecting sensor 5 shown in FIG. 3).

According to a sixth aspect of the present invention, the one or more image forming units use semiconductor lasers (laser scanner units 2a to 2d shown in FIG. 1).

According to a seventh aspect of the present invention, the one or more image forming units use light emitting diodes.

According to an eighth aspect of the present invention, the plurality of color components include yellow, magenta, and cyan.

According to a ninth aspect of the present invention, a plurality of color component images formed of different color developers by one or a plurality of image forming units in accordance with a plurality of color component signals supplied are provided. In a method of adjusting an image forming apparatus that forms a multicolor image by superimposing on a body, a forming step of forming a predetermined color pattern for detecting an image forming density on the image carrier (step (1) in FIG. 7) )), A detection step of detecting the image density of the predetermined color pattern formed on the image carrier (steps (2) to (11) in FIG. 7), and An adjusting step (steps (12) and (13) in FIG. 7) of adjusting the image forming timing and the image forming density by the one or more image forming units for each color based on the change in the image density. Things.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] An image forming apparatus according to a first embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing the structure of a multicolor image forming apparatus to which the image forming apparatus according to the first embodiment of the present invention can be applied.

In the drawing, reference numerals 2a to 2d denote yellow (Y), magenta (M), cyan (C), and black (B
k) Exposure and scanning of the photosensitive drums la to ld by exposure light based on each color component signal input from a controller 1001 shown in FIG. 2 described later by a laser scanner unit (a laser scanner unit using a semiconductor laser) of each color. An electrostatic latent image is formed on drums la to ld.

The photosensitive drums la to ld sequentially include yellow (Y), magenta (M), cyan (C), and black (B
k) A photosensitive medium of each color. 3a to 3d indicate yellow (Y), magenta (M), cyan (C), and black (B
k) The developing units of each color use the electrostatic latent images on the photosensitive drums la to ld to convert the electrostatic latent images into yellow (Y),
Magenta (M), cyan (C), and black (Bk) are visualized (developed) with toner of each color. Reference numeral 4 denotes an intermediate transfer member, which is an image carrier that carries toner images of respective colors that are superimposedly transferred from the photosensitive drums la to ld.

Reference numeral 5 denotes a density detection sensor, for example, an infrared light reflection type surface reflectance measurement sensor for measuring the density of the toner image formed on the intermediate transfer member 4. Reference numeral 7 denotes a transfer belt which conveys a recording medium such as recording paper and transfers the toner image on the intermediate transfer body 4 to the recording medium. A fixing device 6 fixes the toner image on the recording medium to the recording medium by heat and pressure.

The operation of each section will be described below.

A controller 1001 shown in FIG.
Scanner units 2a to 2
d scans the photosensitive drums la to ld to form electrostatic images, and visualizes the electrostatic images with the toner stored in the developing units 3a to 3d. The image formed on each photosensitive drum is superimposed and transferred onto the intermediate transfer body 4 to form a color image, and the color image is transferred to the recording paper conveyed by the transfer belt 7. Thereafter, the recording paper is conveyed to the fixing device 6, and the fixing device melts the toner by heat, and then completely fixes the toner melted by the pressure roller to the recording paper.

FIG. 2 is a block diagram illustrating the configuration of the image forming apparatus according to the first embodiment of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals.

In the image forming apparatus 1000, 1001
Is a controller, which is controlled by the CPU 1012 in the ROM 101.
3 and a control program stored in an external memory 1014 such as a hard disk, a floppy disk, or a magneto-optical disk. And outputs an image signal as output information to the printer engine 1016. The font ROM of the ROM 1013 stores font data and the like used when generating the output information. Further, a data ROM of the ROM 1013
Stores information used on the host computer 2000 for a printer that does not include the external memory 1014 such as a hard disk.

The CPU 1012 is connected to the input unit 101
8, bidirectional communication processing with the host computer 2000 is possible via the interface 2100, and information and the like in the image forming apparatus 1000 are transferred to the host computer 20.
00 is configured to be notified. 1019 is RAM
The CPU 1012 functions as a main memory, a work area, and the like for the CPU 1012, and is configured so that the memory capacity can be expanded by an optional RAM connected to an additional port (not shown). The CP in the controller 1001
U1012, the CPU 1017 in the printer engine,
It has a timer inside and can measure time.

The RAM 1019 is used for an output information development area, an environment data storage area, an NVRAM, and the like. The external memory 1014 such as a hard disk (HD) and an IC card is a memory controller (MC) 1
020 controls the access. External memory 101
Reference numeral 4 is connected as an option and stores font data, emulation programs, form data, and the like. An operation unit 1021 includes switches for operation and various settings, an LED display, an LCD display, and the like.

The number of the external memory 1014 is not limited to one, and at least one external memory is provided. In addition to the built-in fonts, an option card and a plurality of external memories storing programs for interpreting printer control languages of different languages are connected. It is configured to be able to. NV (not shown)
A RAM may be provided to store various setting information from the operation unit 1021.

In order to print the color component signal sent from the CPU 1012 of the controller 1001, the actuator 1022 is operated at a predetermined timing in the printer engine 1016, and various detection systems 1023 (density) taken in at the time of operation are operated. A CPU 1017 is provided for performing a control by feeding back a signal from the detection sensor 5 (including the detection sensor 5) to the operation. Further, an RO storing a control program as shown in a flowchart described later, which is executed by the CPU 1017, is stored in the RO.
M1030 is provided. Furthermore, the controller 1
001, magenta (M), cyan (C),
Supply timing data (registration correction data) of each color component signal of black (Bk) and each color component signal to be described later to the laser scanner units 2a to 2d, an optimum development bias at the time of development, and a detection system 1023 (density detection sensor 5 Is included in the RAM 1031 for storing data read from the RAM 1031.

Note that the CPU 1017 determines the RAM based on the color registration correction data stored in the RAM 1031.
The supply timing of each color component signal stored in 1031 to the scanner units 2a to 2d is controlled to control yellow (Y), magenta (M), cyan (C), and black (B).
The writing timing of each latent image in k) is controlled.

The CPU 1017 has a RAM 1031
The yellow (Y) and magenta by the developing units 3a to 3d are based on the optimal developing bias for the development of each color component of yellow (Y), magenta (M), cyan (C) and black (Bk) stored in The development density of each color is controlled by controlling the development bias of each color component of (M), cyan (C), and black (Bk).

Reference numeral 1040 denotes a patch pattern forming circuit for density correction control processing, and a plurality of patch patterns having different densities (shown in FIGS. 3 and 4 described later) are formed on the photosensitive drums la to ld while sequentially changing the developing bias. It is formed and transferred to the intermediate transfer member 4.

FIG. 3 is a diagram for explaining the configuration of the density detecting sensor 5 shown in FIG. 1. The same components as those in FIG. 1 are denoted by the same reference numerals.

In the figure, reference numeral 102 denotes an irradiation section of the density detection sensor 5 for irradiating infrared light. Reference numeral 101 denotes a light receiving unit of the density detection sensor 5, which measures scattered light reflected from the intermediate transfer body 4. 105A and 105B (hereinafter, collectively referred to as 105) are a plurality of patch patterns formed on the intermediate transfer body 4 and have the same pattern, but a density difference is generated by changing the developing bias.

Hereinafter, the density correction control processing operation will be described.

First, a plurality of patch patterns 105 having different densities are formed on the respective photosensitive drums la to ld while sequentially changing the developing bias by the patch pattern forming circuit 1040 for density correction control processing, and transferred to the intermediate transfer member 4. I do. The patch pattern 105 is irradiated with infrared light from the irradiation unit 101 of the density detection sensor 5 and the reflected scattered light is measured by the light receiving unit 102 of the density detection sensor 5 to determine
Import to U1017. The CPU 1017 converts the sensor output voltage into a density, associates the density of the patch pattern with each developing bias at the time of executing the control, calculates the developing bias for obtaining the desired density, and calculates it at that time. RAM 103 as the optimum developing bias for
1 and used until the next density correction control process.
As a result, the optimum developing bias voltage at that time can be set.

FIG. 4 is a developed view of the surface of the intermediate transfer member 4 shown in FIG. 1 when the plurality of patch patterns 105 having different development densities shown in FIG. Correspondingly, the same components as those in FIG. 3 are denoted by the same reference numerals.

As shown in the figure, the patch patterns 105A and 105B formed with different developing biases have yellow (Y) and yellow (Y) continuously formed in parallel with the drum traveling direction.
These are magenta (M), cyan (C), and black (Bk) patterns.

In the image forming area of the intermediate transfer member 4,
A plurality of patch patterns (patch patterns 105A, 105B,
...) are formed continuously in parallel with the drum traveling direction. Since it is not necessary to print these plurality of patch patterns on recording paper, the transfer belt 7 does not convey the recording paper, and the secondary transfer from the intermediate transfer body 4 to the transfer belt 7 is not performed.

FIGS. 5A and 5B are schematic diagrams for explaining the patch pattern shown in FIG. 4 in detail. FIG. 5A corresponds to the patch pattern used in the density correction control processing of the present invention, and FIG. This corresponds to a patch pattern used in the density correction control processing.

In the figure, 401Y, 401M, 401
C and 401Bk are yellow (Y), magenta (M), cyan (C), and black (Bk) color component patch images sequentially formed in parallel with the drum traveling direction of the intermediate transfer body 4. 402Y, 402M, 402C, 4
02Bk is the leading edge of the yellow (Y), magenta (M), cyan (C), and black (Bk) colors in order, and the respective color component patch images 401Y, 401M, 401C, and 401B.
This corresponds to the tip of k, and has been subjected to edge enhancement processing. An example of the edge enhancement processing will be described below.

Each of the color component patch images 401Y, 401M,
401C and 401Bk are, for example, "2/3" of the maximum density.
Developed at about the density and edge-enhanced parts (front edges 402Y, 402M, 402C, 402Bk for each color)
Is developed at the maximum density, for example.

Further, each color component patch image 401Y, 40
Although 1M, 401C, and 401Bk differ depending on the model (the size of the image forming unit and the like), for example, “15 mm to 30 mm”
A square or rectangle having an arbitrary length within the range of the degree, and an edge emphasized portion (the leading edge 402Y, 40Y of each color)
2M, 402C, and 402Bk) are, for example, “2
mm to 3 mm "or less.

However, each color component patch image 401Y, 40
1M, 401C, 401Bk and leading edge 40 of each color
2Y, 402M, 402C, and 402Bk are not limited to only the size and the development density.

That is, the patch pattern for performing the image control processing of the present invention shown in (a) is an edge processing with respect to the patch pattern for performing the conventional density correction control processing shown in (b). It has been subjected to.

FIG. 6 is a characteristic diagram showing a density output waveform of the density detection sensor 5 shown in FIG. 3, and corresponds to the measurement result of the patch pattern shown in FIG. Note that the horizontal axis indicates time, and the vertical axis indicates output voltage.

In the figure, 601Y, 601M, 601
C and 601Bk are color component patch images 401Y and 4
602Y, 602M, 602C, and 602 corresponding to the output voltages of the portions other than the leading ends of 01M, 401C, and 401Bk.
Bk is the leading edge 402Y, 402M, 40 of each color in order.
This corresponds to an output voltage of 2C, 402Bk.

By detecting the output voltages 602Y, 602M, 602C, and 602Bk of the leading edge of each color, the density detecting sensor 5 detects the leading end of the color component patch image, that is, the writing start position of each color image, and reliably detects each color component. Registration deviation can be detected.

The output voltages 601Y and 601 of each color component patch image for each patch pattern shown in FIG.
By detecting M, 601C, and 601Bk, the density of each patch pattern with respect to the developing bias at that time can be detected.

Hereinafter, the density correction control processing in this embodiment will be described.

First, a plurality of patch patterns of different densities visualized on the respective photosensitive drums la to ld while changing the developing bias sequentially by the patch pattern forming circuit 1040 for the density correction control processing shown in FIG. Is transferred to the intermediate transfer member 4 as shown in FIG. Since it is not necessary to print this patch pattern on the recording paper, the transfer belt 7 does not convey the recording paper, and the secondary transfer to the transfer belt 7 is not performed.

Further, as shown in FIG. 5A, the patch pattern has been subjected to an emphasis process at the tip of the color component patch image, and when this patch pattern is read by the density detection sensor 5, it becomes as shown in FIG. It shows a simple waveform. By using a patch pattern having such a design, the edge of each color can be detected simultaneously when the density of each color patch image with respect to the development bias is detected by the density correction control processing, and the edge of each color image can be easily detected. it can.

Hereinafter, the image registration correcting operation of the image forming apparatus according to the present invention will be described with reference to the flowchart of FIG.

FIG. 7 is a flowchart showing an example of the procedure of the adjustment processing (density correction control processing, image registration correction processing) of the image forming apparatus according to the present invention, in which the CPU 1017 shown in FIG. Execute according to the program. (1) to (13)
Indicates each step.

First, a patch pattern is formed on the intermediate transfer member 4 (1), a variable i for counting edges is initialized and “1” is substituted (2), and reading of the first patch pattern is started ( 3). When the density sensor 5 detects the first edge (4), the timer counter A is started and "1" is added to the variable i (5). Next, when the i-th edge (here, the second edge) is detected (6), the value of the timer counter A is substituted for a variable Ai (here, i = 2) (7). Thereafter, “1” is added to the variable i (8), and “i =
It is determined whether or not “5” (9). If it is not “i = 5”, the process returns to step (6). If it is determined that “i = 5”, the process proceeds to step (10). . That is, the same processing is repeated until the fourth edge.

When the reading of the first patch pattern is completed, the next patch pattern is read (10), and it is determined whether or not reading of all the patch patterns has been completed (11). If so, the reading process of step (10) is repeated, and if it is determined that reading of all patch patterns has been completed, the process proceeds to step (12).

The variables A2, A3, and A4 are detected by the detection processing of the first to fourth edges in steps (2) to (9).
Is substituted for the distance from the first edge to each edge. Here, the values of the variables A2, A3, and A4 are compared with the original distances (designed (ideal) distances from the first edge to each edge stored in the ROM 1030) to detect respective errors. Based on the detected error data, a registration correction (adjustment) process for updating the registration correction data of each color stored in the RAM 1031 is performed (12).

Next, the optimum developing bias for each color is calculated based on the change in the density of each patch pattern read in steps (2) to (11), and the calculated optimum developing bias is stored in the RAM 1031. The stored density correction (adjustment) process is performed (13), and the process ends.

Thereafter, at the time of image formation, the CPU 1017 controls the supply timing of each color component signal to the laser scanner units 2a to 2d based on the registration correction data of each color stored in the RAM 1031 and stores the same in the RAM 1031. The developing bias of the developing devices 3a to 3d is controlled based on the optimum developing bias.

As described above, in the present embodiment, in the density correction control processing sequence, the image registration processing is executed based on the detection result of the patch image for the image density correction control processing by the density detection sensor 5. In addition, it is possible to improve the usability by realizing a reduction in non-printing time such as an execution time of the density correction control processing and the image registration processing.

Further, as described above, the image registration processing and the density correction control processing are performed based on the detection result of the patch pattern for the image density correction control processing by the density detection sensor 5, so that the image registration processing is performed. Therefore, it is not necessary to provide an expensive CCD image sensor as in the related art, and only an inexpensive density detection sensor is required. Therefore, an inexpensive image forming apparatus with high image quality and small space can be provided.

Further, one type of patch pattern (a patch pattern for image density correction control processing) is formed on an image carrier such as an intermediate transfer member, and the formed patch pattern is read to obtain image registration. Correction processing,
Since both of the density correction control processes can be executed,
Since the consumption of toner during the adjustment process can be reduced, the number of image formations on the image carrier can be reduced, and contamination can be minimized, so that the life of the image carrier can be prevented from being shortened.

In this embodiment, the laser scanner units 2a to 2a using a semiconductor laser as an image forming unit are used.
Although the case where d is provided has been described, a configuration in which a plurality of image forming units using LEDs are provided may be provided.

Further, the image forming apparatus of the present invention is provided with a color reader unit capable of reading a color original image from an original, and the laser scanner units 2a to 2d are configured to receive image light based on the original image read by the color reader unit. A copying machine that forms images by irradiating the drums 1a to 1d may be used.

Further, the RAM 1031 is stored in NVRAM, E
A non-volatile memory such as an EPROM or a non-volatile memory card may be used.

Thus, the adjusting process is executed at a predetermined cycle, when replacing parts such as the scanner units 2a to 2d and the photosensitive drums 1a to 1d, and when necessary, so that the adjusting process is not required every time the power is turned on. After turning on the power, a high-quality multicolor image can be formed in a short first print time.

[Second Embodiment] In the first embodiment,
Laser scanner units 2a to 2d for each color
Has described the case where the images formed on the photosensitive drums 1a to 1d for each color are respectively transferred onto the intermediate transfer member 4, but one laser scanner unit is used to transfer the images.
Images of different colors may be sequentially formed on one photosensitive drum, and may be transferred to the intermediate transfer body every time one color is formed. Hereinafter, the embodiment will be described.

FIG. 8 is a cross-sectional view illustrating the structure of an image forming apparatus according to a second embodiment of the present invention, and corresponds to a multicolor image forming apparatus having a rotary developing device, and is the same as FIG. Those are denoted by the same reference numerals.

In the figure, reference numeral 109 denotes a scanner unit (laser scanner unit using a semiconductor laser).
An electrostatic latent image is formed on the photosensitive drum 110 based on an image signal sent from the printer controller 1016 shown in FIG. A black (Bk) developing device 101 includes a black (Bk) color developer therein, and has a photosensitive drum 11.
The electrostatic latent image on 0 is developed with a black developer (Bk).
Reference numeral 102 denotes a rotary developing device which includes a yellow developing section having a yellow (Y) developer therein, a magenta developing section having a magenta (M) developer therein, and a cyan (C) developer. The electrostatic latent image on the photosensitive drum 110 is developed in yellow (Y), magenta (M), and cyan (C) colors.

Reference numeral 104 denotes an intermediate transfer drum.
The developed image developed on 10 is superimposed and transferred onto a transfer material. The density detection sensor 5 measures the density of the toner image formed on the intermediate transfer drum 104.

As described above, R for supplying image signals to the laser scanner units 2a to 2d for forming images of different colors.
Laser scanner units 2a to 2d from AM1013
By incorporating a registration correction sequence for controlling the supply timing of the image data into the density correction control processing sequence, the processing time for performing image correction can be reduced. As a result, the non-printing time is shortened, which leads to improvement in usability.

In the first embodiment, the yellow
The case where the image formation timing of another color is controlled (registration correction) using (Y) as a reference color has been described. However, the reference color is not limited to yellow (Y), but is magenta (M). The present invention is applicable regardless of whether it is cyan (C) or black (Bk).

As described above, the storage medium storing the program codes of the software for realizing the functions of the above-described embodiments is supplied to the system or the apparatus, and the computer (or CPU or MP) of the system or the apparatus is supplied.
It goes without saying that the object of the present invention is also achieved when U) reads out and executes the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, C
DR, magnetic tape, nonvolatile memory card, RO
M, EEPROM and the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) And the like perform part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, The CPU provided in the function expansion board or function expansion unit performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

Further, the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, by reading a storage medium storing a program represented by software for achieving the present invention into the system or the apparatus, the system or the apparatus can enjoy the effects of the present invention. .

Further, by downloading and reading out a program represented by software for achieving the present invention from a database on a network by a communication program, the system or apparatus can be
It is possible to enjoy the effects of the present invention.

[0084]

As described above, according to the first, fifth, and eighth aspects of the present invention, one or a plurality of image forming units differ depending on a plurality of supplied color component signals. In an image forming apparatus that forms a multicolor image by superimposing a plurality of color component images formed by color developers on an image carrier, a detecting unit detects an image forming density formed on the image carrier. The second control means detects the image density of the predetermined pattern detected by the detection means, based on a change in the image density of the predetermined pattern detected by the detection means. The image registration timing and the image formation density are controlled for each color component, so that the image registration correction processing and the density correction are performed based on the detection result of a predetermined color pattern for detecting the image formation density formed on the image carrier. By executing both adjustment processes of the correction control process, it is possible to improve the usability by shortening the execution time (non-printing time) of the density correction control process and the image registration correction process, and to improve the usability. By reducing the number of times of image formation on the image carrier, consumption of toner during the adjustment process can be reduced, and contamination of the image carrier can be minimized.

According to the second aspect of the present invention, the predetermined color pattern is a patch pattern in which each color component image whose front end is emphasized parallel to the image carrier moving direction is formed in parallel with the image carrier moving direction. Since a plurality of color patterns are successively formed at different densities, it is possible to reliably detect registration deviation of each color.

According to the third aspect, the second control means sets a tip of each of the emphasized color component images based on a change in image density of the predetermined pattern detected by the detection means. Detection is performed, and the timing of supplying each color component signal to the one or more image forming units is controlled for each color component signal in accordance with the detection result, so that registration deviation of each color can be reliably corrected. .

According to the fourth aspect, the second control means sends the one or more image forming units to the one or more image forming units based on a change in image density of the predetermined pattern detected by the detection means. Since the developing bias voltage is controlled for each color, an optimum developing bias voltage for each color component can be calculated.

According to the ninth aspect, a plurality of color component images formed with different color developers by one or more image forming units in response to a plurality of supplied color component signals are formed on the image carrier. In the adjusting method of the image forming apparatus for forming a multi-color image by superimposing on the image forming apparatus, a predetermined color pattern for detecting an image forming density is formed on the image carrier, and the color pattern formed on the image carrier is formed. Detect the image density of a predetermined color pattern,
Since the image forming timing and the image forming density by the one or more image forming units are adjusted for each color based on the detected change in the image density of the predetermined pattern, the image forming unit is formed on the image carrier. Performing both the image registration correction process and the density correction control process based on the detection result of the predetermined color pattern for detecting the image formation density, and executing the density correction control process and the image registration correction process It is possible to improve the usability by shortening the time (impossible printing time), to reduce the number of image formations on the image carrier during the adjustment process, to reduce the toner consumption during the adjustment process, and to reduce the image quality. Contamination on the carrier can be minimized.

Therefore, it is possible to improve the usability by shortening the execution time (printing impossible time) of the density correction control processing and the image registration correction processing, and to form an image on the image carrier during the adjustment processing. By reducing the number of times, it is possible to reduce the consumption of toner during the adjustment process and to minimize the contamination of the image carrier.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a multicolor image forming apparatus to which an image forming apparatus according to a first exemplary embodiment of the present invention can be applied.

FIG. 2 is a block diagram illustrating a configuration of an image forming apparatus according to the first exemplary embodiment of the present invention.

FIG. 3 is a diagram illustrating a configuration of a density detection sensor illustrated in FIG.

FIG. 4 is a developed surface view of the intermediate transfer member shown in FIG. 1;

FIG. 5 is a schematic diagram illustrating the patch pattern shown in FIG. 4 in detail.

FIG. 6 is a characteristic diagram showing a density output waveform of the density detection sensor shown in FIG.

FIG. 7 is a flowchart illustrating an example of an adjustment process (density correction process, image registration correction process) of the image forming apparatus according to the present invention.

FIG. 8 is a sectional view illustrating a configuration of an image forming apparatus according to a second exemplary embodiment of the present invention.

[Explanation of symbols]

 5 Density detection sensor 1017 CPU 1030 ROM 1031 RAM 1040 Density correction control processing patch pattern forming circuit

Claims (9)

[Claims] 1. A method according to claim 1, further comprising the step of:
An image forming apparatus for forming a multicolor image by superimposing a plurality of color component images formed by different color developers by one or more image forming units on an image carrier; First control means for controlling the one or more image forming units so as to form a predetermined color pattern on the image carrier; and image density of the predetermined color pattern formed on the image carrier. Detecting the image formation timing and the image forming density by the one or more image forming units for each color component based on a change in the image density of the predetermined pattern detected by the detecting means. An image forming apparatus, comprising: a second control unit for controlling. 2. The image processing apparatus according to claim 1, wherein the predetermined color pattern includes a plurality of patch patterns in which respective color component images whose tips are emphasized parallel to the image carrier moving direction are continuously formed at different densities parallel to the image carrier moving direction. The image forming apparatus according to claim 1, wherein the color pattern is formed by forming a color pattern. 3. The method according to claim 2, wherein the second control unit detects a tip of each of the emphasized color component images based on a change in image density of the predetermined pattern detected by the detection unit. 3. The image forming apparatus according to claim 2, wherein the timing of supplying each color component signal to the one or more image forming units is controlled for each of the color component signals. 4. The image forming apparatus according to claim 2, wherein the second control unit changes a developing bias voltage to the one or more image forming units for each color based on a change in image density of the predetermined pattern detected by the detecting unit. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus controls the image forming apparatus. 5. An image forming apparatus according to claim 1, wherein said detecting means is an infrared light reflection type surface reflectance measuring sensor. 6. The image forming apparatus according to claim 1, wherein the one or more image forming units use a semiconductor laser. 7. The image forming apparatus according to claim 1, wherein the one or more image forming units use light emitting diodes. 8. The image forming apparatus according to claim 1, wherein the plurality of color components include yellow, magenta, and cyan. 9. A method according to claim 1, further comprising the step of:
Detecting a density of image formation in an image forming apparatus that forms a multicolor image by superimposing a plurality of color component images formed by different color developers by one or more image forming units on an image carrier; Forming a predetermined color pattern on the image carrier for detecting the image density of the predetermined color pattern formed on the image carrier; and detecting the image density of the predetermined color pattern formed on the image carrier. Adjusting the image forming timing and the image forming density of each of the one or more image forming units for each color based on the change in the image density of the pattern of the image forming apparatus. Adjustment method.