JP2003207976A - Color image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color image forming apparatus capable of realizing the complete correction of the deviation of color registration, the reduction of what is called downtime, that means, a state where image forming operation is impossible, the decrease of toner consumption for forming a registration control patch, or the lightening of load imposed on a cleaning member and further the decrease of waste toner recovery capacity by predicting and correcting the deviation of the color registration caused by temperature rise in the main body of the apparatus. <P>SOLUTION: The color image forming apparatus is equipped with a temperature detection means for detecting temperature in the main body of the apparatus, and a prediction and correction means for predicting and correcting the deviation of the color registration in a plurality of image forming units based on the temperature in the main body of the apparatus detected by the temperature detection means. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus such as a color printer or a color copying machine, and
In a so-called tandem type color image forming apparatus including a plurality of image forming units that form images of mutually different colors, a registration (hereinafter, referred to as an image forming position of each color image formed by the plurality of image forming units). (Registration is also simply referred to as "register").

[0002]

[Patent Document 1] JP-A-1-142674

[Patent Document 2] JP-A-1-142680

[Patent Document 3] JP-A-1-183676

[Patent Document 4] Japanese Patent No. 2625130

[Patent Document 5] Japanese Patent No. 2921856

[0003]

2. Description of the Related Art Conventionally, as a so-called tandem type color image forming apparatus having a plurality of image forming units of this type, there is, for example, one shown in FIG. This tandem type color image forming apparatus, as shown in FIG. 31, has four image forming units 100 that form toner images of different colors such as yellow, magenta, cyan, and black.
Y, 100M, 100C, 100K, and these image forming units 100Y, 100M, 100C, 100
The Ks are arranged in parallel at regular intervals along the horizontal direction. The above four image forming units 100
Y, 100M, 100C, and 100K have the same configuration except that the color of the toner image to be formed is different,
After the surface of the photoconductor drum 101 is uniformly charged by the contact type charging device 102, the surface of the photoconductor drum 101 is subjected to image exposure by the exposure device 103, and an electrostatic latent image corresponding to the image information of each color. To form. The electrostatic latent image formed on the surface of the photosensitive drum 101 is visualized as a toner image by the developing device 104 of the corresponding color, and the toner image is transferred by the charger 105 for primary transfer to the intermediate transfer belt. It is transferred onto 106 in sequence. The toner remaining on the surface of the photosensitive drum 101 is removed by the cleaning device 107 to prepare for the next image forming step.

The intermediate transfer belt 106 includes four image forming units 100Y, 100M, 100C and 100K.
A plurality of rollers 108 to 111 including driving rollers are circulated and driven at a speed equal to the rotation speed of the photosensitive drum 101. The yellow, magenta, cyan, and black toner images sequentially and multiply transferred onto the intermediate transfer belt 106 are transferred to the intermediate transfer belt 10 at a secondary transfer position below the intermediate transfer belt 106.
By the secondary transfer roll 112 that comes into contact with the surface of the sheet 6, the images are collectively transferred onto the recording paper 113 fed at a predetermined timing. After that, the recording paper 113 is conveyed to the fixing device 114, undergoes a fixing process by heat and pressure by the fixing device 114, is discharged to the outside of the device, and a full-color or monochrome image is formed.

By the way, in such a tandem type color image forming apparatus, a plurality of image forming units 100Y and 10Y are provided.
A plurality of image forming units 100Y, 100M, 100C are controlled by controlling an image forming position of each color image formed by 0M, 100C, 100K, that is, registration.
A registration control technique is adopted in which the registrations of the images of the respective colors formed at 100K are accurately matched with each other.

As for an image forming apparatus adopting this registration control technique, for example, JP-A-1-142674 and JP-A-1-142 are known.
As disclosed in Japanese Unexamined Patent Publication No. 680, Japanese Patent Application Laid-Open No. 1-183676, etc., as shown in FIG. 32, the ROS of each image forming unit 100Y, 100M, 100C, 100K.
A predetermined image position recognition pattern 120 is formed on the photoconductor drum 101 by 103, and the image position recognition pattern 120 of each color formed on each photoconductor drum 101 is transferred to the intermediate transfer belt 106. First, the images are sequentially primary-transferred to the upper side, sampled by the CCD 121 arranged on the downstream side of the final stage image forming unit 100K, and the color shift of the image position recognition pattern 120 of each predetermined color is determined according to the positional relationship of the sampling data. It is detected how much difference there is from the positional relationship on the assumption that there is no difference, and the registration deviation (hereinafter referred to as “registration deviation”) amount of each color is calculated from the detected data.
In the image forming apparatus, each image forming unit 1
ROS103 of 00Y, 100M, 100C, 100K
There is proposed a method of providing high-quality image with less misregistration by correcting the writing timing or the position of an optical system component.

The image position recognition pattern 120 of each color transferred onto the intermediate transfer belt 106 is removed by a cleaning device 115 that cleans the surface of the intermediate transfer belt 106.

As a technique relating to this registration control device, for example, JP-A-1-142674, JP-A-1-142680, and JP-A-1-183 are available.
Some are disclosed in Japanese Patent No. 676, etc.

As a technique for correcting the deterioration of the color registration deviation amount due to the temperature rise inside the machine, those disclosed in Japanese Patent Nos. 2625130 and 2921856 have been already proposed. .

The techniques disclosed in Japanese Patent No. 2625130 and Japanese Patent No. 2921856 are such that when the temperature rise in the machine changes by a predetermined temperature after the power is turned on or the registration control is carried out, or the previous registration control is carried out. The register control sequence is operated when the predetermined temperature changes by a predetermined temperature.

To explain further, the above-mentioned Japanese Patent No. 2525
The image forming apparatus according to No. 130 has a plurality of image stations each having an image carrier, a moving body that moves to transfer each image formed on the plurality of image carriers at a transfer position, and A reading unit for reading each registration mark image formed by a plurality of image stations and transferred onto the moving body, and a positional deviation between the images formed by the plurality of image stations based on the reading result of the reading unit. Correction means for correcting the temperature, temperature detection means for detecting the temperature inside the apparatus, the plurality of image stations form the registration mark image and transfer each registration mark image onto the moving body, and the reading means Each of the registration mark images transferred on the moving body is read, and the correction means performs the correction operation based on the read result. And control means for controlling on the basis of the execution of the registration correction sequence to an output of said temperature detecting means,
It is configured to include.

Further, the color image forming apparatus according to the above-mentioned Japanese Patent Publication No. 2921856 has an endless conveying means for conveying the transfer material, and the transfer material arranged at a predetermined interval along the moving direction of the endless conveying means. In a color image forming apparatus having a plurality of image recording means for sequentially recording images of different colors, a temperature detecting means for detecting the temperature inside the apparatus, and a temperature detected by the temperature detecting means is increased every predetermined temperature. A control means for forming a detection pattern corresponding to each color on the endless conveying means by the plurality of image forming means, a pattern detection means for detecting the detection pattern, and a detection result by the pattern detection means. A correction processing unit that calculates the positional deviation amount of each color and corrects the positional deviation amount of each color is configured.

On the other hand, in order to correct the deterioration of the color registration deviation amount due to the temperature rise in the machine, Japanese Patent Laid-Open No. 1-9666 has been proposed.
As disclosed in Japanese Patent Publication No. 5, a technique has already been proposed in which the writing start timing in the sub-scanning direction is controlled based on only the difference from the current temperature with the lowest temperature in the actual machine being used as a reference.

[0014]

However, the above-mentioned prior art has the following problems. That is, the above-mentioned Japanese Patent No. 2625130 and Japanese Patent No. 2921.
In the case of the technique disclosed in Japanese Patent Publication No. 856, the execution of the resist correction sequence is controlled based on the output of the temperature detecting means, or the temperature detected by the temperature detecting means for detecting the temperature inside the apparatus is Every time the temperature rises,
The plurality of image forming units are configured to form a detection pattern, and to detect and correct the detection pattern.

However, in the above image forming apparatus,
Depending on the frequency of image forming operations and the contents of the image forming operations to be performed, the temperature rise inside the machine is not uniform, and the change characteristic of the color registration deviation with respect to the temperature inside the machine is not linear. When the execution of the sequence is controlled based on the output of the temperature detection means, or the color registration misregistration correction operation is performed every time the temperature inside the machine rises by a predetermined temperature, pattern formation or unnecessary The detection operation has been executed and the image forming operation cannot be performed due to the registration control sequence operation. The frequency of so-called downtime, the toner consumption amount for forming the registration control patch, or the load on the cleaning member. There is a problem that it causes an unnecessary increase in the waste toner recovery capacity and the like.

Further, in the case of the technique disclosed in the above-mentioned Japanese Patent Laid-Open No. 1-96665, writing in the sub-scanning direction is performed based on only the difference from the current temperature with the lowest temperature in use of the actual machine in the machine as a reference. Although it is configured to control the timing, the temperature rise inside the machine is not uniform and the change characteristic of the registration deviation with respect to the temperature inside the machine is not linear, so the color caused by the temperature increase inside the machine There is a problem that the registration shift amount cannot be sufficiently corrected.

Therefore, the present invention has been made in order to solve the above-mentioned problems of the prior art, and its object is to predict and correct a color registration shift due to a temperature rise in the apparatus main body. This makes it possible to sufficiently correct the color registration misregistration, reduce the so-called downtime when the image forming operation is impossible, reduce the toner consumption for forming the registration control patch, or reduce the load on the cleaning member. An object of the present invention is to provide a color image forming apparatus capable of reducing the amount of waste toner collected.

Another object of the present invention is to correct the registration control if the downtime, the toner consumption amount for forming the registration control patch, the load on the cleaning member, etc. are the same as those of the conventional apparatus. It is to provide a color image forming apparatus capable of further improving accuracy.

[0019]

In order to solve the above-mentioned problems, the invention described in claim 1 is provided with a plurality of image forming units for forming images of mutually different colors. In a color image forming apparatus that forms a color image by transferring formed images of different colors to a recording medium directly or via an intermediate transfer body, the temperature inside the main body of the color image forming apparatus is detected. It is configured to include a temperature detection unit and a prediction correction unit that predicts and corrects the color registration deviation amount in the plurality of image forming units based on the temperature inside the apparatus main body detected by the temperature detection unit. is there.

In the predictive correction of the color registration deviation amount, it goes without saying that the color registration deviation detection pattern is not formed.

Here, as the "pattern detecting member", for example, an intermediate transfer member to which an image formed by each image forming unit is primarily transferred is used, but the present invention is not limited to this. It may be a recording medium conveying member such as a belt for conveying the recording medium, or a transfer member for finally transferring a plurality of images transferred in multiple on the intermediate transfer body onto the recording medium.

According to a second aspect of the present invention, in the color image forming apparatus according to the first aspect, the predictive correction means detects the temperature inside the apparatus main body detected by the temperature detection means. According to the value, a predictive correction operation for predicting and correcting the color registration deviation amount at a constant temperature interval is executed.

Further, the invention described in claim 3 is the color image forming apparatus according to claim 1, wherein
The predictive correction unit is configured to execute a predictive correction operation of predicting and correcting the color registration deviation amount at a temperature interval that changes in accordance with the detected value of the temperature inside the apparatus main body detected by the temperature detection unit. It was done.

According to a fourth aspect of the invention, in the color image forming apparatus according to the second or third aspect of the invention, the color image forming apparatus is responsive to detected values of respective temperatures in the apparatus main body detected by the temperature detecting means. In addition, at least one prediction correction table for predicting and correcting the color registration shift amount is provided.

Further, in the invention described in claim 5, in the color image forming apparatus according to claim 2 or 3, the temperature detection means detects the temperature of each inside of the apparatus body. In addition, at least one predictive correction calculation formula for predicting and correcting the color registration shift amount is provided.

According to a sixth aspect of the present invention, in the color image forming apparatus according to any one of the first to fifth aspects, each time when the predictive correction operation of the color registration deviation amount is executed, the next color The configuration is such that the upper limit value and the lower limit value of the temperature interval for performing the predictive correction operation of the registration deviation amount are determined.

Further, the invention described in claim 7 is the color image forming apparatus according to claim 1, wherein
The color registration deviation detection pattern formed by each of the image forming units is transferred onto the same pattern detection member, and the color registration deviation detection pattern transferred onto the pattern detection member is detected, and the color registration deviation detection pattern is detected. A registration deviation correction operation executing unit that executes a registration deviation correction operation is provided, and the predictive correction unit is at least 1 while the registration deviation correction operation is executed by the registration deviation correction operation execution unit.
It is configured to execute the prediction correction operation of the color registration deviation amount once.

Here, the "registration deviation correction operation" means an operation of forming a registration deviation detection pattern, detecting the registration deviation detection pattern, and correcting the registration deviation.

Furthermore, the invention described in claim 8 is
8. The color image forming apparatus according to claim 7, wherein the predictive correction unit uses the predictive correction operation based on the temperature inside the apparatus main body when the registration deviation correction operation execution unit executes the registration deviation correction operation. Is configured to set the temperature at which

According to a ninth aspect of the present invention, in the color image forming apparatus according to the seventh aspect, the predictive correction unit is a reference temperature when the predictive correction operation is performed by the predictive correction unit. As the above, the temperature at the time of executing the previous prediction correction operation is used.

Further, the invention described in claim 10 is the color image forming apparatus according to claim 7,
The predictive correction unit predicts the color registration deviation amount predicted and corrected by the predictive corrector, the relative temperature difference from the temperature at the previous predictive correction operation, and the temperature in the apparatus main body at the time of executing the predictive correction this time. It is configured to be calculated based on.

The invention described in claim 11 is the color image forming apparatus according to claim 7,
The predictive correction unit predicts the color registration deviation amount that the predictive correction unit predicts and corrects, the relative temperature difference from the temperature at the time of executing the previous registration deviation correction operation, and It is configured to calculate based on the temperature and.

Further, the invention described in claim 12 is
8. The color image forming apparatus according to claim 7, wherein the predictive correction unit predicts the color registration deviation amount predicted and corrected by the predictive correction unit as a relative temperature difference from the temperature at the previous predictive correction operation. , Which is configured to be calculated based on the smaller of the relative temperature differences from the temperature at the time of executing the previous registration deviation correction operation and the temperature inside the apparatus main body at the time of executing the current prediction correction Is.

Furthermore, the invention described in claim 13 is provided with a plurality of image forming units for forming images of different colors, and the images of different colors formed by the plurality of image forming units are directly Alternatively, in a color image forming apparatus that forms a color image by transferring onto a recording medium via an intermediate transfer member, a prediction correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided, The predictive correction unit is configured to execute predictive correction each time an image is formed on a recording medium.

Here, "every time an image is formed on the recording medium" includes both color and black and white formed on the recording medium, but only the formation of a color image may be counted.

Further, the invention described in claim 14 is
A plurality of image forming units that form images of different colors are provided, and images of different colors formed by the plurality of image forming units are transferred onto a recording medium directly or through an intermediate transfer member, In a color image forming apparatus for forming a color image, a predictive correction unit for predicting and correcting the color registration deviation amount in the plurality of image forming units is provided, and the predictive correction unit is provided each time an image is formed on a recording medium. The color registration deviation amount is predicted, and the prediction correction is executed when the predicted value of the color registration deviation amount exceeds a predetermined deviation amount.

The invention as set forth in claim 15 is provided with a plurality of image forming units for forming images of different colors, and the images of different colors formed by the plurality of image forming units are directly or directly In a color image forming apparatus that forms a color image by transferring onto a recording medium via an intermediate transfer member, a predictive correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided. The predictive correction means is configured to execute predictive correction each time the color image forming apparatus is activated.

Further, the invention as set forth in claim 16 is provided with a plurality of image forming units for forming images of different colors, and the images of different colors formed by the plurality of image forming units are directly or directly In a color image forming apparatus that forms a color image by transferring onto a recording medium via an intermediate transfer member, a predictive correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided. The prediction correction unit is configured to predict the color registration deviation amount each time the color image forming apparatus is activated, and execute the prediction correction when the predicted value of the color registration deviation amount exceeds a predetermined deviation amount. Is.

The invention as set forth in claim 17 is provided with a plurality of image forming units for forming images of different colors, and the images of different colors formed by the plurality of image forming units are directly or directly In a color image forming apparatus that forms a color image by transferring onto a recording medium via an intermediate transfer member, a predictive correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided. The predictive correction unit is configured to execute the predictive correction of the color registration deviation amount based on the integrated start-up time of the color image forming apparatus every time a predetermined time elapses after starting the color image forming apparatus. It is a thing.

Here, the "predetermined time" may be a fixed time or a changing time interval.

Further, the invention described in claim 18 is
A plurality of image forming units that form images of different colors are provided, and images of different colors formed by the plurality of image forming units are transferred onto a recording medium directly or through an intermediate transfer member, In a color image forming apparatus that forms a color image, a predictive correction unit that predicts and corrects the color registration deviation amount in the plurality of image forming units is provided, and the predictive correction unit starts the color image forming apparatus, Every time an image is formed on a predetermined number of recording media, the color registration deviation amount is predicted and corrected based on the accumulated number of recording media of the color image forming apparatus.

Here, the "predetermined number" may be a fixed number or a varying number. that's all,
Although the content of the claim that predicts the color registration deviation amount and corrects the deviation amount has been described, the correction amount that corrects the deviation amount is predicted and corrected without predicting the color registration deviation amount. Is also good. That is, the predicted color registration shift amount,
Since the correction amount corresponding to the predicted color registration shift amount has a fixed relationship, the correction amount for correcting the shift amount is directly predicted and calculated without predicting the color registration shift amount. You may correct it.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 2 is a schematic configuration diagram showing a tandem type digital color printer as an image forming apparatus according to Embodiment 1 of the present invention. Further, this tandem type digital color printer is equipped with an image reading device, and also functions as a full-color copying machine. The digital color printer may of course be provided with no image reading device and form an image based on image data output from a personal computer or the like (not shown). The digital color printer may also have a function as a facsimile.

In FIG. 2, reference numeral 1 denotes a main body of a tandem type digital color printer (color image forming apparatus). The digital color printer main body 1 reads an image of an original 2 on an upper side of one end thereof. Image reading device (IIT: Image Input Terminal)
l) 4 is provided and image data output from the image reading device 4 or a personal computer (not shown) or the like is sent to the inside of the digital color printer body 1 via a telephone line, a LAN, or the like. An image processing apparatus (IPS: which performs predetermined image processing on image data)
Image Processing System) 1
2 and an image output device (IOT: Image Output Terminal) that outputs an image based on image data subjected to predetermined image processing by the image processing device 12.
l) 100 are provided.

Inside the main body 1 of the digital color printer, black (K), yellow (Y), magenta (M), as image forming units constituting the image output apparatus 100,
Cyan (C) image forming units 13K and 13
Y, 13M, and 13C are arranged at regular intervals along the horizontal direction. Further, below the four image forming units 13K, 13Y, 13M, and 13C, an intermediate transfer body that transfers the toner images of the respective colors sequentially formed by these image forming units in a state of being superposed on each other. The transfer belt 25 is disposed so as to be rotatable in the arrow direction. Then, the intermediate transfer belt 25
The toner images of the respective colors, which are transferred in multiple layers on the upper side, are fed to the paper feed tray 3
After being collectively transferred onto a recording sheet 34 as a recording medium fed from the recording sheet 9 or the like, the recording sheet 3 is fixed by the fixing device 37.
It is fixed on the sheet 4 and discharged to the outside.

In the embodiment shown in FIG. 2, the image output apparatus 100 is configured so that each image forming unit 13K, 13Y,
After the toner images of black (K), yellow (Y), magenta (M), and cyan (C) formed of 13M and 13C are primary-transferred on the intermediate transfer belt 25 in a state of being superimposed on each other, The case where the color image is formed by collectively performing the secondary transfer on the recording paper 34 from the intermediate transfer belt 25 has been described.
Not limited to this, as shown in FIG. 30, as shown in FIG. 30, black (K), yellow (Y), magenta (M) formed by the image forming units 13K, 13Y, 13M, and 13C,
A toner image of each color of cyan (C) is transferred onto the recording sheet 34 conveyed by a sheet conveying belt 25 'serving as a recording medium conveying member in a state of being superimposed on each other to form a color image. Of course, it can also be applied to the above. In addition, each image forming unit 1
The order of colors of 3K, 13Y, 13M, and 13C is not limited to black (K), yellow (Y), magenta (M), and cyan (C), but yellow (Y), magenta (M). Of course, the order of cyan, cyan (C) and black (K) may be arbitrary.

FIG. 3 shows the structure of a tandem type digital color printer as an image forming apparatus according to the first embodiment of the present invention in more detail.

Although the configuration of the present invention will be described here using a tandem type digital color printer, the present invention is also effective in a color copying machine / facsimile or the like. The same applies to the following embodiments.

In FIG. 3, reference numeral 1 denotes a main body of a tandem type digital color printer, and a platen cover 3 for pressing an original 2 against a platen glass 5 is provided on an upper portion of one end side of the digital color printer main body 1. An image reading device 4 for reading an image of the document 2 placed on the platen glass 5 is provided. This image reading device 4
Illuminates the original 2 placed on the platen glass 5 with the light source 6, and reflects the reflected light image from the original 2 on the full rate mirror 7, the half rate mirrors 8 and 9, and the imaging lens 1.
Scanning exposure is performed on an image reading element 11 such as a CCD via a reduction optical system including 0, and the color material reflected light image of the original 2 is scanned by the image reading element 11 at a predetermined dot density (for example, 16 dots / mm). ) Is configured to read.

The color material reflected light image of the document 2 read by the image reading device 4 is, for example, document reflectance data of three colors of red (R), green (G), blue (B) (each 8 bits). As the image processing apparatus 12 (Image Proce
The image processing device 12 sends predetermined data such as shading correction, positional deviation correction, lightness / color space conversion, gamma correction, frame erasing, color / moving editing, etc. to the reflectance data of the original 2. Image processing is performed.

The image data which has been subjected to the predetermined image processing by the image processing device 12 as described above has four colors of yellow (Y), magenta (M), cyan (C) and black (K) (each 8 bits). The image forming units 13K and 13Y of the respective colors of black (K), yellow (Y), magenta (M), and cyan (C) are converted into the color material gradation data (raster data) of the color as described below. , 13M, 13C ROS
14K, 14Y, 14M, 14C (Raster Ou
tputScanner) to send these ROS
In 14K, 14Y, 14M, and 14C, image exposure with laser light is performed according to image data of a predetermined color.

By the way, inside the tandem type digital color printer main body 1, as described above, four image forming units 13K of black (K), yellow (Y), magenta (M) and cyan (C) are provided. , 13Y, 13
M and 13C are arranged in parallel in the horizontal direction at regular intervals.

These four image forming units 13K,
13Y, 13M, and 13C have the same structure except that the colors of images to be formed are different, and are roughly classified into a photosensitive drum 15 as an image carrier that rotates at a predetermined rotation speed in the arrow direction. A primary charging scorotron 16 as a charging means for uniformly charging the surface of the photoconductor drum 15 and an image corresponding to each color are exposed on the surface of the photoconductor drum 15 to form an electrostatic latent image. The image forming apparatus includes a ROS 14, a developing device 17 for developing the electrostatic latent image formed on the photoconductor drum 15, and a cleaning device 18.

As shown in FIG. 3, the ROS 14 modulates the semiconductor laser 19 according to the image data of each color and emits the laser beam LB from the semiconductor laser 19 according to the image data. The laser beam LB emitted from the semiconductor laser 19 is deflected and scanned by the rotary polygon mirror 22 via the reflection mirrors 20 and 21, and again passes through the reflection mirror 21 and a plurality of reflection mirrors 23 and 24 to the photosensitive drum 15. Scanned and exposed on top.

From the image processing device 12, black (K),
The image data (raster data) of each color is sequentially output to the ROSs 14K, 14Y, 14M, and 14C of the image forming units 13K, 13Y, 13M, and 13C of yellow (Y), magenta (M), and cyan (C), respectively. ROS
A laser beam LB emitted from 14K, 14Y, 14M, and 14C according to image data is scanned and exposed on the surface of each photoconductor drum 15K, 15Y, 15M, and 15C to form an electrostatic latent image. Each photoconductor drum 1
The electrostatic latent images formed on 5K, 15Y, 15M and 15C are developed by the developing devices 17K, 17Y, 17M and 17C.
Black (K), yellow (Y), magenta (M),
It is developed as a toner image of each color of cyan (C).

The image forming units 13K, 13Y,
13M, 13C photoconductor drums 15K, 15Y, 15
The toner images of black (K), yellow (Y), magenta (M), and cyan (C), which are sequentially formed on M and 15C, are respectively formed in the image forming units 13K, 13Y, 13M, and 1.
The primary transfer rolls 26K, 26Y, and 26 are provided on the intermediate transfer belt 25 as an intermediate transfer body, which is disposed below 3C.
Multiple transcription by M and 26C. The intermediate transfer belt 25 includes a drive roll 27 and an idle roll 2
8, steering roll 29, idle roll 30
, A backup roll 31 and an idle roll 32 are wound around with a constant tension, and are driven in a predetermined direction in an arrow direction by a drive roll 27 which is rotationally driven by a dedicated drive motor (not shown) having excellent constant speed. It is designed to be circulated at the speed of. As the intermediate transfer belt 25, for example, a synthetic resin film having flexibility such as polyimide is formed into a strip shape, and both ends of the synthetic resin film formed into the strip shape are connected by welding or the like to form an endless belt. A belt-shaped member is used.

The toner images of black (K), yellow (Y), magenta (M), and cyan (C) transferred in multiple layers on the intermediate transfer belt 25 are backup rolls 31.
The recording sheet 34 is secondarily transferred onto the recording sheet 34 by a pressing force and an electrostatic force by the secondary transfer roll 33 that is pressed against the recording sheet 34, and the recording sheet 34 to which the toner images of the respective colors are transferred is fixed by the two conveyor belts 35 and 36. It is conveyed to the container 37. The recording paper 34 onto which the toner images of the respective colors have been transferred is
The fixing device 37 receives the fixing process with heat and pressure, and the sheet is discharged onto a discharge tray 38 provided outside the printer body 1.

The recording paper 34 is, as shown in FIG.
A paper feed path 46 including a paper feed roller 42 and a pair of paper feed rollers 43, 44, 45 from a plurality of paper feed trays 39, 40, 41 having a predetermined size.
The sheets are once conveyed to the registration roll 47 via the. The recording paper 34 supplied from any one of the paper feed trays 39, 40, 41 is delivered onto the intermediate transfer belt 25 by a registration roll 47 which is rotationally driven at a predetermined timing.

Then, the four image forming units 13K and 13K for the black, yellow, magenta and cyan colors are formed.
In Y, 13M, and 13C, as described above, the toner images of black, yellow, magenta, and cyan are sequentially formed at predetermined timings.

The photosensitive drums 15K, 15Y,
15M and 15C are after the toner image transfer process is completed,
The cleaning devices 18K, 18Y, 18M, and 18C remove residual toner, paper dust, and the like to prepare for the next image forming process. Further, the intermediate transfer belt 25 is cleaned of residual toner by a cleaning device 48 for the belt and a cleaning blade or a brush.

By the way, in the tandem type digital color printer configured as described above, as described below, due to various factors such as vibration during transportation and installation, temperature change inside the machine, and the like, each image forming unit Positional fluctuations occur in the photoconductor drum, etc., causing image misregistration (registration misregistration).
Occurs.

First, the image forming units 13K and 13
In Y, 13M and 13C, photosensitive drums 15K and 1K
If the positions of 5Y, 15M, and 15C are misaligned, the distance (optical path length) between the ROS 14K, 14Y, 14M, and 14C and the photoconductor drums 15K, 15Y, 15M, and 15C changes as shown in FIG. The deviation of the magnification in the direction (laser beam scanning direction) and the deviation of the magnification in the left and right directions in the main scanning direction occur. The image forming units 13K, 13Y,
ROS 14K, 14Y, 14 at 13M, 13C
M, 14C and photoconductor drums 15K, 15Y, 15M, 1
If there is a positional shift along the main scanning direction in 5C, a margin shift in the main scanning direction occurs as shown in FIG.

Further, each image forming unit 13K, 13
In Y, 13M, and 13C, as shown in FIG. 6, when the rotation axes of the photoconductor drums 15K, 15Y, 15M, and 15C are inclined, skew deviation occurs. Further, when the photosensitive drums 15K, 15Y, 15M, and 15C have a positional deviation along the sub-scanning direction as shown in FIG. 7, a deviation of the margin in the sub-scanning direction occurs.

In addition to the above registration shift, in each of the image forming units 13K, 13Y, 13M and 13C,
As shown in FIG. 8, the photosensitive drums 15K, 15Y, 15
If there are speed fluctuations in M, 15C and the intermediate transfer belt 25,
Periodic fluctuations in the sub-scanning direction (AC fluctuations) occur, which causes color registration deviations (hereinafter referred to as “color registration deviations”) between different colors. Further, when the intermediate transfer belt 25 has a meander in the main scanning direction, as shown in FIG. 9, a periodic fluctuation (AC fluctuation) in the main scanning direction occurs, which causes a color registration shift between different colors. Occurs.

As described above, due to various factors, the magnification deviation in the main scanning direction, the lateral magnification deviation in the main scanning direction, the skew deviation, the sub scanning margin deviation, the main scanning margin deviation, the sub scanning periodic deviation, Scan periodic deviation occurs,
As shown in FIG. 10, when the positional deviations of these images are superimposed, a DC-like deviation (uniform deviation) or an AC-like deviation (periodic deviation) occurs, resulting in a color registration deviation.

Therefore, in this embodiment, as shown in FIG. 11, a color registration deviation detection pattern 50 is formed on the intermediate transfer belt 25 at a predetermined timing, and the color registration deviation detection pattern 50 is formed. The image forming units 13K, 13Y, and
A color shift image is formed after the registration shift correction operation for correcting the color shifts of 13M and 13C is executed. The detecting means 60 are arranged at both ends along the width direction of the intermediate transfer belt 25, for example, but if necessary, both ends and the center thereof along the width direction of the intermediate transfer belt 25. A plurality (three or more) may be provided at equal intervals along the width direction of the portion or the intermediate transfer belt 25, and are appropriately arranged according to the type of color registration deviation to be detected.

As shown in FIGS. 12 and 13, the color registration deviation detection pattern 50 includes a first chevron mark 51KK made of a first reference color and a second chevron mark made of a second measured color. The pattern in which all the measured colors are combined is used with the mountain-shaped mark 51YY and the third mountain-shaped mark 51KY consisting of the first color and the second color as one unit. The combination of the patterns 50 shown in FIG. 12 is one block in the reference color and the target color.
When this pattern is actually used, as shown in FIG. 13, it is repeatedly formed for several blocks and is sampled. Here, the first embodiment of the present invention will be described on the assumption that sampling for one round of the intermediate transfer belt 25 is performed. The signal for outputting the color registration deviation detection pattern 50 is stored in advance in, for example, the ROM of the printer output control means 85 as the registration deviation correction operation execution means of the image processing apparatus 12 described later. Further, it goes without saying that the color registration shift detection pattern 50 may have another shape.

FIG. 14 is a perspective view showing the pattern detector 60 for detecting the color registration deviation.

In FIG. 14, 61 is the pattern detector 6.
0 is a housing, and 62a and 62b are intermediate transfer belts 25.
The two light emitting elements 63a and 63a respectively illuminate the pattern 50 for detecting the color registration deviation formed on the upper side.
Reference numerals b, 64a, and 64b denote two sets of light receiving elements that respectively receive reflected light from different mountain-shaped marks 51 of the color registration shift detection pattern 50 formed on the intermediate transfer belt 25. The two sets of light receiving elements 63a, 63b and 64a, 64b are arranged as shown in FIG. The two light emitting elements 62
As the a and 62b, for example, an LED or the like that emits light of a specific wavelength or light having a predetermined wavelength distribution is used, and these light emitting elements 62a and 62b are located at one detection position on the intermediate transfer belt 25. Are arranged so as to illuminate each other from a diagonal direction on the opposite side which is inclined by a predetermined angle. The two sets of light receiving elements 63a, 63b and 64a, 64b are arranged such that their central portions face each other or contact each other, and both end portions are inclined downward by a predetermined angle with respect to the horizontal direction. Elements 63a, 63b and 6
4a, 64b, and the light receiving elements 63a, 63
As shown in FIG. 12, b, 64a, and 64b are set so that the detection timing and the detection angle of the reflected light are different from each other.

As shown in FIG. 15, when the pattern detector 60 detects the color registration deviation detection pattern 50 formed on the intermediate transfer belt 25, the linear mark of the color registration deviation detection pattern 50 is detected. As shown in FIG. 15A, one of the light receiving elements 63b outputs a smooth mountain-shaped waveform first, and after a slight delay, the other light receiving element 63a also outputs the waveform shown in FIG. ), A smooth mountain-shaped waveform is output. And
By amplifying the waveforms output from these two light receiving elements 63b and 63a and then taking the difference, or by taking the difference and then amplifying it, the waveform temporarily falls into a large mountain shape as shown in FIG. 16 (c). Then, an output waveform that rises in a large mountain shape can be obtained. Therefore, by taking the difference between the waveforms output from the two light receiving elements 63a and 63b, it is possible to use a highly accurate sensor such as a CCD,
As shown in FIG. 15D, the linear mark 51 of the color registration shift detection pattern 50 can be detected with high resolution and high accuracy.

By using the color registration shift detecting pattern 50 as described above, the image forming units 13K, 13Y, 13M, 1 for black, yellow, magenta and cyan are formed.
The misregistration of each color toner image formed in 3C is detected.

Then, in the tandem type digital color printer according to this embodiment, the image forming units are formed in accordance with the registration deviation amount of the toner image of each color detected by using the color registration deviation detection pattern 50. The operation of correcting the position of the image to be performed is performed. It should be noted that the calculation of the correction amount and the correction operation for correcting the position of the image formed by each image forming unit in accordance with the positional shift amount of the toner image of each color detected using the color registration shift detection pattern 50 are performed. For example, this is performed by the printer output adjusting means 74 described later.

First, in order to correct the coarse margin in the main scanning direction, as shown in FIG. 16A, the ROSs 14K and 14 of the image forming units 13K, 13Y, 13M and 13C are used.
Y, 14M, 14C, the photosensitive drums 15K, 15Y,
When exposing an image on 15M and 15C, the recording start position of the image in the main scanning direction is SOS (Start Of
Scan) is determined by the rising edge of the signal
By changing the count number of VCLK, which is a clock signal from the rise of the OS signal to the activation of the LS (Line Sync) signal, which is the enable signal for actual image exposure, in the main scanning direction in units of 1 VCLK (pixel) It is possible to correct the recording start position of the image in.

To correct the coarse margin in the sub-scanning direction, as shown in FIG. 16A, the ROSs 14K and 14 of the image forming units 13K, 13Y, 13M and 13C are used.
Y, 14M, 14C, the photosensitive drums 15K, 15Y,
When an image is exposed on 15M and 15C, the recording start position of the image in the sub-scanning direction is determined by the rising edge of the TR0 signal, but from the rising edge of the TR0 signal, the PS (Page) which is an enable signal for actual image exposure.
1) by changing the count number of SOS which is a clock signal until the Sync signal becomes active.
The image recording start position in the sub-scanning direction can be corrected in units of S (pixels).

Next, in order to correct the skew, FIG.
As shown in (b), ROS 14K, 14Y, 14M,
By tilting the final stage mirror 24 in 14C,
The inclination of the laser beam exposed on the photosensitive drums 15K, 15Y, 15M, and 15C is corrected.

Further, in order to correct the magnification along the main scanning direction, as shown in FIG.
The pixel width is changed by changing the frequency of the VCLK (video clock: main scanning pixel output clock) signal that determines the pixel interval when exposing an image along the main scanning direction in 4Y, 14M, and 14C. It is possible to correct the magnification along the main scanning direction.

To correct a small margin along the main scanning direction, as shown in FIG.
By changing the phase of the signal, it is possible to correct a small margin of one pixel or less along the main scanning direction.

On the other hand, in order to correct a small margin along the sub-scanning direction, the phase of the SOS signal is changed by controlling the rotation of the polygon mirror 22 as shown in FIG. 17B. It is possible to correct a small margin below the pixel in the sub-scanning direction.

Further, as shown in FIG.
S14K, 14Y, 14M, 14C and photosensitive drum 15
When the distance between K, 15Y, 15M, and 15C is different between the IN side and the OUT side of the device, as shown in FIG. 18B, the frequency of the VCLK signal is balanced according to the deviation of the magnification balance. By changing the correction value and the inclination, the magnification balance is corrected.

Further, in order to correct an arbitrary magnification (magnification / balance / partial magnification difference) deviation, as shown in FIG.
VCLK (Video clock: Main scan pixel output clock)
A signal and a plurality of pulses VCLK1 to VCLK whose phase is shifted in the same cycle are set in advance, and the plurality of pulses VCLK1 to VCLK1 to VCLK1 are set in accordance with magnification, balance (horizontal magnification difference), or partial magnification deviation. 8 is selected appropriately and VCL
By creating K, it becomes possible to correct an arbitrary magnification (magnification / balance / partial magnification difference) deviation.

Further, in order to change the pixel positions of the image data in the main scanning direction and the sub scanning direction, as shown in FIG.
When the correction amount of the pixel position calculated from the shift amount corresponds to, for example, −5 pixels in the main scanning direction and +4 pixels in the sub scanning direction,
The data of the (N, M) data address is changed to (N-5, M +
4) By changing to the data address, it is possible to correct the deviation in the main scanning direction and the sub scanning direction only by processing the image data without changing the image writing clock.

When an LED bar in which LED elements are linearly arranged is used as the image exposure device instead of the ROS, the pixel output timing in the sub-scanning direction is controlled by changing the light emission timing. Is possible.

By the way, in this embodiment, a plurality of image forming units for forming images of different colors are provided, and the images of different colors formed by the plurality of image forming units are directly or intermediately transferred. In a color image forming apparatus for forming a color image by transferring the color image onto a recording medium via a temperature detecting means for detecting a temperature in the color image forming apparatus main body, and an inside of the apparatus main body detected by the temperature detecting means. It is configured to include a prediction correction unit that predicts and corrects the color registration deviation amount in the plurality of image forming units based on the temperature of.

Further, in this embodiment, the predictive correction means predicts the color registration deviation amount at a temperature interval that changes according to the detected value of the temperature inside the apparatus main body detected by the temperature detecting means. It is configured to perform a predictive correction operation for correction.

Further, in this embodiment, at least one predictive correction table for predicting and correcting the color registration deviation amount according to the detected value of each temperature in the apparatus main body detected by the temperature detecting means is provided. Is configured.

Furthermore, in this embodiment, every time the predictive correction operation of the color registration deviation amount is executed, the upper limit value and the lower limit value of the temperature interval for executing the next predictive correction operation of the color registration deviation amount are determined. Is configured.

FIG. 2 is a block diagram showing a control circuit of a tandem type digital color printer as a color image forming apparatus according to the first embodiment of the present invention.

In FIG. 2, reference numeral 71 denotes an IOT main controller which also has a function as a registration deviation correcting operation executing means for controlling an image forming operation in the image output apparatus 100 of the digital color printer and a predictive correcting means.
Is an ESS for inputting image data from the image reading device 4 or a personal computer (not shown) input through the interface 73, 74 is a RAM provided inside the ESS 73, and 75 is a temperature inside the printer body 1. A temperature sensor as a temperature detecting means, a RAM 76 provided inside the image processing apparatus 12, and a pattern detector 60 for detecting the color registration deviation detecting pattern 50 formed on the intermediate transfer belt 25, respectively. It is shown. The temperature sensor 75 is arranged in the central portion of the printer body 1, for example.

In the tandem type digital color printer according to the first embodiment having the above-mentioned structure, the registration control operation for correcting the color registration deviation caused by the temperature rise in the apparatus main body is efficiently performed as follows. By making it possible to perform the image forming operation, the so-called downtime is reduced, the toner consumption for forming the registration check patch is reduced, or the load on the cleaning member is reduced. It is possible to reduce the collection capacity.

That is, in the tandem-type digital color printer according to the first embodiment, when the temperature (absolute temperature) in the printer body 1 changes such as rising or falling, FIG.
As shown in FIG. 2A, the color registration shift amount changes.
Here, as the color registration deviation amount, for example, the maximum registration deviation amount of the main scanning magnification deviation is used, but the color registration deviation amount is not limited thereto. It is needless to say that other deviation amounts such as deviation, skew deviation, BOW deviation, main scanning registration deviation amount: side registration deviation, lateral magnification deviation, partial magnification deviation, and the like may be used.

Temperature inside the printer body 1 (absolute temperature)
As shown in FIG. 22, the color registration temperature characteristic curve showing the variation of the color registration deviation amount with respect to the color registration temperature characteristic curve has a constant relationship with the absolute temperature in the printer body 1, and the information of the color registration temperature characteristic curve is shown. Is stored in advance in the memory in the printer body 1, the color registration deviation amount can be predicted and corrected.

Here, the information on the color registration temperature characteristic curve means, as shown in FIG. 22, a changing temperature interval Δt1 which produces a constant color registration deviation amount Δerror corresponding to the absolute temperature in the printer body 1. Δt2, Δt3, Δt
Means 4.

In this embodiment, the color registration deviation prediction pattern is corrected and the color registration deviation detection pattern formed by each image forming unit is transferred onto the same pattern detection member at a predetermined timing. Then, the color registration shift detection pattern transferred onto the pattern detection member is detected, and the color registration shift correction operation is executed.

When the state when this color registration shift correction operation is completed is A in FIG. 22, the absolute temperature T in the printer body 1 at this time is T0 based on this state A.
Memorize as. If this temperature T0 can be grasped, the absolute temperature conditions T1, T2, T at which the specified color registration deviation change amount Δerror after the temperature rise from the temperature T0 is generated.
3, T4 is calculated.

These absolute temperature conditions T1, T2, T3,
T4 is the temperature at which the color registration misregistration prediction correction is performed,
The color registration deviation of the temperature T1 is "+ Δerror" with respect to the reference, and similarly, the temperature T2 is "+ 2Δerror" with respect to the reference.
The color registration deviation of r "is" -Δerro "at the temperature T4.
It means the temperature at which the color registration shift of r ″ occurs.

The temperature T in the printer body 1 detected by the temperature sensor 75 is T1, T2, T3, T.
Each time the number reaches 4, the prediction correction based on the temperature of the color registration shift is performed. At this time, a correction operation for correcting the color registration deviation amount predicted from the temperatures T1, T2, T3, and T4 is executed. For example, the temperature T
In the case of 1, the color registration shift amount is “ΔΔerror” because the color registration shift is only Δerror from the reference.
Correction, and at temperature T2, similarly +2 with respect to the reference
Since the color registration shifts by Δerror, the color registration shift amount is corrected by “−2Δerror” to obtain the temperature T
Similarly, in the case of 4, the color registration shift amount is “+ 2Δ, because the color registration shift is −Δerror from the reference.
It is sufficient to correct only "error". The same applies to the temperature T3. Although four temperature conditions of T1, T2, T3, and T4 are set here, finer temperature steps may be used.

More specifically, in the first embodiment, as shown in FIG. 21, the IOT main controller 71 first executes the color registration deviation correction operation (step 101), and then uses the temperature sensor 75. The temperature T in the printer body 1 is detected and confirmed (step 10
2) The detected temperature T in the printer body 1 is set to the reference temperature T0 (step 103), and the condition temperatures T1, T2, T3, T4 for performing the prediction correction of the color registration deviation are calculated.

FIG. 22B shows an example of a temperature parameter table for calculating the condition temperatures T1, T2, T3, T4 for executing the predictive correction of the color registration deviation. In addition,
Here, the usable temperature of the digital color printer is
Although the temperature is set to 10 ° C. or higher and lower than 45 ° C., it may be set so that it can be used in a temperature range other than this. Further, in FIG. 22B, the absolute temperature represents the detected value itself of the temperature inside the printer body 1 detected by the temperature sensor 75, and the numerical value of the absolute temperature in this table is equal to or higher than the temperature, It shows the temperature range below the temperature. For example, in FIG. 22B, the absolute temperature of 10 (° C.) means a temperature range of 10 ° C. or higher and lower than 15 ° C. In addition, the term “absolute temperature” does not indicate a physical absolute temperature, but an absolute temperature and a cabin temperature with respect to a relative temperature (a temperature difference between a certain temperature and a certain temperature). If 10 ℃, 10 ℃, 2
This is because 0 ° C. means a temperature of 20 ° C.

In this table, as shown in FIG. 22A, the absolute temperature in the printer body 1 is, for example, the temperature TA.
When the temperature changes by a temperature Δt1 (= TB-TA) from the temperature TB, for example, the lead registration deviation is a constant amount Δerr.
The temperature change amount when only or is changed is used as a parameter. Here, the lead registration deviation amount will be described as an example of the color registration deviation amount on the vertical axis, but the present invention is not limited to this, and as described above, other sub-scanning registration deviation amounts: skew deviation, BOW deviation. Main scan registration deviation amount: A table for each element to be corrected is required among side registration deviation, magnification deviation, lateral magnification deviation, partial magnification deviation, and the like. Each of the correction target elements may be all or some of the color registration shifts. Also, a table may be provided for each correction target element, or a common table may be used for those that can be shared (the same absolute temperature change amount per unit deviation).

Further, the temperature change amount when the maximum registration shift amount changes by the constant amount Δerror is used as a parameter, for example, when the in-machine temperature changes by the temperature change amount, for example, the main scanning magnification shift Since there is a possibility that registration deviation will occur by the maximum registration deviation amount (allowable value) of
This is because if the registration shift correction operation is executed at this timing, the number of registration shift correction operations can be minimized.

When the temperature at the first registration deviation correction operation is 28.0 ° C. in absolute temperature, the condition temperature at the next registration control operation is as follows with reference to FIG. Tu and the lower limit value Tl. Tupper = 28.0 + 2.5 = 30.5 ° C. Tlower = 28.0-2.5 = 25.5 ° C.

Here, 2.5 ° C. in the formulas for calculating the upper limit value Tu and the lower limit value Tl is the upper limit (upper) parameter of the row of 25 ° C. or more and less than 30 ° C. in the table shown in FIG. 22 (b). The values are 2.5 ° C. and 2.5 ° C. of the lower parameter.

After executing the registration deviation correction operation (registration control operation) as described above, the IOT main controller 71, as shown in FIG. 21, based on the current temperature T, the condition temperature for the next registration deviation correction operation. The upper limit value Tu and the lower limit value Tl are determined (step 103), and it is determined whether it is the temperature prediction correction timing (step 104).

Here, as the temperature prediction correction timing, when the power of the apparatus is turned on, when the print job is started, at the beginning of each page in the job, at the end of each page in the job,
For example, when the print job is completed, when the sleep mode is entered, when the sleep mode is restored, or when the copy / print configuration is changed.

When the copy / print configuration is changed, it means changes such as image size change, resolution change, image resolution or process speed change corresponding to paper (thick paper, plain paper, OHP).

Then, the IOT main controller 71
Waits until the temperature prediction correction timing comes (step 104), and when the temperature prediction correction timing comes, the temperature sensor 75
The temperature T in the printer body 1 is detected and confirmed by (step 105), and it is determined whether the in-machine temperature T is equal to or higher than the upper limit value Tn or lower than the lower limit value Tn determined at the last registration control operation (step 106). ), If the in-machine temperature T is not higher than the upper limit value Tn or lower than the lower limit value Tn, the process returns to step 104, and if the in-machine temperature T is not lower than the upper limit value Tn or lower than the lower limit value Tn, the temperature Tn is concerned. A prediction correction operation is performed (step 107).

As described above, by performing the predictive correction operation of the color registration deviation based on the reference temperature T0, it is possible to correct the color registration deviation due to the change of the in-machine temperature T of the printer body 1.

However, in the above digital color printer, in addition to the fluctuation of the internal temperature T, the temporal fluctuation of the image forming apparatus (the temporal change of the drive mechanism parts), the disturbance (the shock when the apparatus is moved, the installation floor environment), the image The color registration deviation state of the reference temperature T0 changes due to factors such as a change in the state of components that affect formation (change in the image carrier due to jam clearing) and replacement of components that affect image formation.

If the color registration deviation amount of the reference temperature T0 changes due to the above various factors, the temperature T1
The prediction correction of the color registration deviation at T2, T3, and T4 also has an error.

Therefore, in the first embodiment, in order to prevent this, the registration deviation correction operation for forming the color registration deviation detection pattern is executed.
The timing for performing this registration deviation correction operation is
Immediately after assembling the device, when installing the device, when turning on the power of the device, when a certain time has elapsed while waiting for the device, when starting a print job,
Examples include the end of the print job, the midway of the print job (after the passage of a certain number of sheets, the passage of a certain time), the transition to the sleep mode, the return to the sleep mode, and the like.

Therefore, the IOT main controller 71
After performing the predictive correction operation for the temperature Tn (step 107), it is determined whether or not it is time to perform the registration deviation correction operation (step 108). And IOT
The main controller 71 returns to step 104 when it is not the timing to execute the registration deviation correction operation,
When it is time to execute the registration deviation correction operation, the process returns to step 101 and the registration deviation correction operation is executed.

In this way, the reference registration deviation correction operation is performed at the predetermined registration deviation correction operation execution timing (step 101), and between these registration deviation correction operations, the color registration which is the processing of the present invention is performed. Execute the predictive correction operation of the deviation.

It should be noted that, in addition to the fluctuation of the in-machine temperature T, when there is almost no factor that causes the fluctuation of the color registration deviation, only the predictive correction operation of the color registration deviation may be executed.

As described above, in this embodiment, the frequency of performing the color registration misalignment correction operation associated with the formation of the color registration misregistration amount detection pattern is increased by executing the color registration misregistration predictive correction operation. The image forming operation is impossible, so-called downtime is reduced, the toner consumption for forming the registration check patch is reduced, or the load on the cleaning member is reduced. It is possible to reduce the recovery capacity.

Further, in the case of the first embodiment of the present invention,
If the downtime, the amount of toner consumed for forming the registration check patch, or the load on the cleaning member is the same as that of the conventional device, the number of registration deviation correction operations is increased to further improve the accuracy of the registration deviation correction operation. It becomes possible.

Second Embodiment The second embodiment will be described by giving the same reference numerals to the same parts as those in the first embodiment. In the second embodiment, prediction correction is performed with a constant temperature interval. It is configured to change the amount of color registration deviation to be made.

That is, in the above-described first embodiment, FIG.
As shown in (a) and (b), temperature interval data (Δt1, Δt) that changes with respect to a constant allowable deviation amount (correction amount).
Although the condition temperature is set by 2, Δt3, t4), the allowable deviation amount (correction value) corresponding to the temperature is set to Δerror as shown in FIG.
1, Δerror2, Δerror3, Δerror
4, it may be configured to be changed like Δerror5. In this case, the maximum deviation amount Δerror
5 must be within the allowable range.

FIG. 23B shows an example of the correction parameter table in the case where the amount of temperature change is kept constant and the amount of correction corresponding to the absolute temperature value is changed when the predictive correction of the color registration deviation is executed. is there. In this case, the usable temperature of the digital color printer is 10 ° C or higher and 45 ° C.
Although it is set to be less than the above, it may be set so that it can be used in a temperature range other than this. Also, FIG.
In (b), the absolute temperature represents the detected value of the temperature inside the printer body 1 detected by the temperature sensor 75, and the numerical value of the absolute temperature in this table is
The temperature range is equal to or higher than that temperature and lower than the next stage temperature.

In the table shown in FIG. 23B, the correction parameter of the color registration deviation is set to the absolute temperature on the assumption that the prediction correction of the color registration deviation is executed every time the temperature in the printer body 1 changes by 5 ° C. It is set so as to be changed corresponding to the value. Here, assuming that the temperature at the time of the initial misregistration correction operation is 24.0 ° C., since it is a predictive correction in steps of 5 ° C., the temperature condition for the next predictive correction is: Tupper = 24.0 + 5.0 = 29.0 C Tlower = 24.0−5.0 = 19.0 ° C. When the in-machine temperature rises and reaches 29.0 ° C., the correction for the lead registration correction amount “3” steps derived from the table of FIG. 23B is executed.

Similarly, when the temperature drops from 29.0 ° C. by 5 ° C. to 24.0 ° C., the lead registration correction amount “−4” steps derived from the table of FIG. 23B is obtained. Perform correction.

The other structure and operation are the same as those in the first embodiment, and the description thereof will be omitted.

The basic prediction correction processing has been described above,
The timing for executing the temperature prediction correction and the timing for executing the registration deviation correction operation which is the reference thereof have been described.

The frequency of registration misregistration correction operations that require formation of the color registration misregistration detection pattern should be as low as possible, and it is desirable to increase the frequency of temperature prediction correction execution instead.

For example, the registration misregistration correction operation that requires the formation of the color registration misregistration detection pattern is executed only immediately after the color image forming apparatus is assembled, and thereafter, the color registration misregistration is corrected by the temperature prediction correction. It is also possible to do so.

In this case, the power supply to the color image forming apparatus may be turned off or the apparatus may enter the sleep mode. At this time, the absolute temperature conditions T1, T2,
It is necessary to hold the data of T3 and T4. in this case,
This data may be held by a non-volatile memory or a storage medium which can replace the non-volatile memory and can maintain the information in a power-off state. As a result, it is possible to perform the predictive correction based on the temperature condition determined during the previous registration deviation correction operation without executing the registration deviation correction operation immediately after the power of the apparatus is turned on.

Further, the registration deviation correction operation which is performed after the power supply of the apparatus for which FCOT or FPOT (the time from the copy / print instruction to the output of the first copy / print) is important and the time of returning from the sleep mode is returned. Corrects the color registration deviation to some extent by performing a prediction correction based on the absolute temperature in advance, and executes the registration deviation correction operation that forms the color registration deviation detection pattern as soon as the first print job is completed (job end). It is also effective to do.

Further, although it is related to FCOT and FPOT,
Even if it is impossible to execute the registration deviation correction operation for forming the color registration deviation detection pattern due to the limitation during warm-up of the fixing device, the prediction correction based on the absolute temperature in the printer body 1 is performed. Is effective.

Third Embodiment FIGS. 24 and 25 show a third embodiment of the present invention. The same parts as those of the first embodiment will be designated by the same reference numerals and will be described below. The form 3 is configured to include at least one predictive correction calculation formula that predicts and corrects the color registration deviation amount in accordance with the detected value of each temperature in the apparatus main body detected by the temperature detecting means.

That is, in the first embodiment,
As shown in FIG. 22A, a color registration characteristic curve showing how the color registration deviation amount changes with respect to the temperature (absolute temperature) in the printer body 1 is obtained in advance, and this color registration characteristic curve is obtained. On the basis of the above, the prediction correction table for predictively correcting the color registration deviation is provided corresponding to the detected value of each temperature in the printer body 1 detected by the temperature sensor.

However, instead of the above prediction correction table,
It is also possible to provide at least one predictive correction calculation formula for predicting and correcting the color registration deviation amount.

Therefore, in the case of the third embodiment, a plurality of straight lines f (t), g (t), h (t) (or at least 1 Approximated with two quadratic curves)
It is stored in a RAM or the like and these approximate expressions (arithmetic expressions) f
From (t), g (t), and h (t), a specific deviation amount Δer
The upper and lower limits of temperature corresponding to ror are calculated, and the predicted correction amount when the temperature is reached is calculated each time.

For example, assuming that the temperature at the time of register shift correction operation (register control operation) is T0, this absolute temperature T0
Is the range of the arithmetic expression function f (t). Note that the temperature range to which the function f (t), which is each arithmetic expression, is applied is predetermined as shown in FIG. Where the function f
(T) can be expressed as follows. Note that A and a indicate the slope and intercept of the function f (t) that represents the approximate straight line. f (t) = At + a (1)

Now, assuming that the allowable temperature range to be obtained is Δt and the constant maximum registration deviation amount is Δerror =, from equation (1), Δerror = AΔt + a (2) Δt = (1 / A) (Δerror-a) (3 ).

Therefore, the temperature upper limit value Tupper and the lower limit value Tlower which determine the start condition of the next prediction correction are: Tupper = T0 + Δt = T0 + (1 / A) (Δerror-a) (4) Tlower = T0-Δt = T0- (1 / A) (Δerror-a) (5).

As an arithmetic expression stored in the RAM, NVRAM, etc., each approximation expression is shown below: f (t) = At + a (1) g (t) = Bt + b (1) ′ h (t) = Ct + c (1 ) ", The information of f (t), g (t), h (t) may be stored as it is, or the parameters A / a and B representing the approximate expression may be stored.
/ B, C / c may be stored as information.

Also, (1 / A) (Δerror-a),
(1 / B) (Δerror-b), (1 / C) (Δer
Ror-c) may be stored as information. Further, the effective temperature range of each approximate expression f (t), g (t), h (t) is also provided as information.

On the other hand, when the temperature range extends over a plurality of functions, the temperature may be calculated by an adjacent function for the error value deviated from the function, or the condition is bad, that is, the shift change amount per temperature is small. There is no problem even if the temperature condition is calculated with a larger function (in this case, the slope is larger).

In this case, for example, as shown in FIG.
When the registration control operation (or the registration deviation prediction correction) is performed, the in-machine temperature is T0, and the temperature T0 is Tb.
When the temperature is near the lower temperature of (approximation temperature of approximate expression f (t) and g (t)), Tu and Tl are calculated once with the function of f (t), and the deviation amount Δerror2 where Tu exceeds Tb is calculated. Only, the temperature may be calculated by the function of g (t) and the upper limit value Tu ′ may be obtained.

However, a function with a large slope, in this case f
Even if the Tu calculated in (t) is used as the upper limit as it is, there is no problem because the allowable deviation amount is not exceeded. In this case, the calculation process is reduced, but the number of operations for predicting and correcting the registration error increases.

In the third embodiment, the case where the calculation process is executed every time based on the approximate expression of the color registration characteristic curve has been described. However, the in-machine temperature T0 at the time of the initial registration control operation is set to a predetermined constant value. If it can be set, the value of each temperature obtained by the approximate expression (1) based on the in-machine temperature T0 at the time of the operation of the initial registration control is calculated in advance and stored in the storage means. You may stay. However, in consideration of the case where the in-machine temperature T0 at the time of the initial registration control operation is different in a state where the printer is actually used, there is at least one temperature interval arithmetic expression that determines the temperature interval as a fixed value, and the in-machine temperature T0 is At the time of detection, a temperature interval for deciding whether to start the registration deviation correction operation may be calculated based on the calculation formula, and these temperature intervals may be stored as fixed values.

The other structure and operation are the same as those of the first embodiment, and therefore the description thereof is omitted.

Embodiment 4 FIG. 26 shows a tandem type full color printer as an image forming apparatus according to Embodiment 4 of the present invention.

In FIG. 26, reference numeral 200 denotes a main body of a tandem type full color printer. Inside the printer main body 200, yellow (Y), magenta (M), cyan (C) and black (K) are provided. Image forming units 201, 202, 203, 204 having photoconductor drums (image carrier) 211, 212, 213, 214 for
Charging roll (contact-type charging device) 2 for primary charging that contacts the photosensitive drums 211, 212, 213, and 214
21, 222, 223, and 224, and an image writing device 230 that irradiates yellow (Y), magenta (M), cyan (C), and black (K) laser beams 231, 232, 233, and 234. The photoconductor drums 211, 212, 21
Developing devices 241, 242, 24 for developing the electrostatic latent image formed on the image forming unit 3, 214 with toners of respective colors of yellow (Y), magenta (M), cyan (C), and black (K).
3, 244 and the four photoconductor drums 211, 21
Two of the photosensitive drums 211, 2, 213 and 214,
The first primary intermediate transfer drum (intermediate transfer member) 251 and the other two photoconductor drums 213 and 214 that come into contact with 212.
Second primary intermediate transfer drum (intermediate transfer member) 2 that contacts the
52 and the first and second primary intermediate transfer drums 251,
Secondary intermediate transfer drum (intermediate transfer member) 2 that contacts 252
53 and a final transfer roll (transfer member) 260 that comes into contact with the secondary intermediate transfer drum 253, a main part thereof is configured.

Photosensitive drums 211, 212, 213, 2
14 are arranged at regular intervals so as to have a common tangent plane. In addition, the first primary intermediate transfer drum 2
51 and the second primary intermediate transfer drum 252 are arranged such that their respective rotation axes are parallel to the photosensitive drums 211, 212, 213, and 214 and are in plane symmetry with a predetermined plane of symmetry as a boundary. ing. Further, the secondary intermediate transfer drum 253 includes the photosensitive drums 211, 212, 213,
214 and the rotation axis are arranged in parallel.

The photosensitive drums 211, 212 and 21
Laser light 231, 232, and 23 corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K) by the image writing device 230 is formed on the surface of the surface 3, 3, 214.
3, 234 are irradiated, and electrostatic latent images corresponding to the input image information for each color are formed. In addition, the photosensitive drum 21
The electrostatic latent images corresponding to the colors of yellow (Y), magenta (M), cyan (C), and black (K) formed on the surfaces of 1, 212, 213, and 214 are the developing devices 24 of the corresponding colors.
It is developed by 1, 242, 243, and 244, and visualized as a toner image of each color of yellow (Y), magenta (M), cyan (C), and black (K) on the photoconductor drums 211, 212, 213, and 214. It

Next, the above-mentioned photosensitive drums 211 and 21
The toner images of yellow (Y), magenta (M), cyan (C), and black (K) formed on Nos. 2, 213, and 214 are the first primary intermediate transfer drum 251 and the second primary intermediate, respectively. Secondary transfer is performed electrostatically on the transfer drum 252.
The yellow (Y) and magenta (M) color toner images formed on the photoconductor drums 211 and 212 are transferred onto the first primary intermediate transfer drum 251 onto the photoconductor drums 213 and 2, respectively.
The cyan (C) and black (K) color toner images formed on the image forming unit 14 are transferred onto the second primary intermediate transfer drum 252, respectively. Therefore, the first primary intermediate transfer drum 251
A monochromatic image transferred from either the photoconductor drum 211 or 212 and a dual color image in which two color toner images transferred from both the photoconductor drums 211 and 212 are superposed are formed on the upper side. become. Also, on the second primary intermediate transfer drum 252, the photosensitive drums 213 and 214 are also provided.
Form a similar monochromatic image and a dual color image.

The single-color or dual-color toner images thus formed on the first and second primary intermediate transfer drums 251 and 252 are electrostatically tertiary-transferred onto the secondary intermediate transfer drum 253. It Therefore, on the secondary intermediate transfer drum 253,
A final toner image from a monochromatic image to a quadruple color image of yellow (Y), magenta (M), cyan (C), and black (K) is formed.

Next, the final toner image from the monochromatic image to the quadruple color image formed on the secondary intermediate transfer drum 253 is tertiaryly transferred to the paper P passing through the paper transport path by the final transfer roll 260. Transcribed. The paper P passes through the paper transport path from the paper feed roll 290 and is fed to the nip portion between the secondary intermediate transfer drum 253 and the final transfer roll 260. After this final transfer step, the final toner image formed on the paper is fixed by the fixing device 270, and a series of image forming processes is completed.

In this embodiment, the final transfer roll 26
0, the secondary intermediate transfer drum 253, or the like, on the image density detection medium, the color registration shift detection pattern 32 is shifted at the same position in the axial direction and in the process direction.
By forming 0 and 321, the color registration deviation detection patterns 320 and 3 of each color can be formed by one optical density detection unit.
21 can be detected. As the color registration shift detection patterns 320 and 321, for example, a pattern as shown in FIG. 27 is used.

In this embodiment, the color registration shift detection pattern 320 on the final transfer roll 260,
321 is transferred, and the optical density sensor 300 detects the densities of the color registration deviation detection patterns 320 and 321 transferred onto the final transfer roll 260.

The optical density sensor 300, as shown in FIG. 28, is provided at the central portion of the final transfer roll 260 in the axial direction.
It is arranged so as to be located on the extension line in the radial direction on the outer periphery of the final transfer roll 260. The optical density sensor 300 is mounted inside the holder 301 in a fixed state. A cleaning device 800 including a blade-shaped final cleaning member 801 is provided below the final transfer roll 260. In FIG. 28, 802 is a toner collection box, 803 is a support frame for the final transfer roll 260, 804 is a static eliminator provided on the support frame 803, and 805 is a bias plate.

The optical density sensor 300 shown in FIG.
As shown in FIG. 9, it is a specular reflection type sensor for detecting specular reflection light, and is composed of an LED or the like arranged at a predetermined incident angle φ with respect to the detection position on the surface of the final transfer roll 260. The light emitting element 302 and the light emitting element 30
In order to detect the specular reflected light that is irradiated from 2 to the detection position on the surface of the final transfer roll 260 and is specularly reflected from the detection position, the reflection angle equal to the predetermined incident angle is detected with respect to the detection position on the surface of the final transfer roll 260. Light receiving element 30 formed of a phototransistor or the like arranged at an angle
3 and 3.

The optical density sensor 300 detects the color registration deviation detection patterns 320 and 321 and corrects the color registration deviation at a predetermined timing.

The other structures and operations are the same as those in the first embodiment, and the description thereof will be omitted.

Fifth Embodiment FIG. 33 shows a fifth embodiment of the present invention. The same parts as those in the first embodiment will be designated by the same reference numerals. The predictive correction means is configured to use the temperature at the time of executing the previous predictive correction operation as the reference temperature when executing the predictive correction operation by the predictive correction means. In addition, in FIG. 33, A to F in the upper diagram are temperature states A to F,
A, B1, B2 to F1 and F2 in the lower diagram are not in color registration and are in states A, B1, B2 to F1 and F2.

Further, in the fifth embodiment, the predictive correction unit predicts the color registration deviation amount predicted and corrected by the predictive correction unit and the relative temperature difference from the temperature at the previous predictive correction operation, and this time. It is configured to be calculated based on the temperature inside the apparatus main body at the time of executing the predictive correction.

Further, in the fifth embodiment, the predictive correction means sets the color registration deviation amount predicted and corrected by the predictive correction means as the relative temperature difference from the temperature at the previous execution of the registration deviation correction operation. The calculation is performed based on the temperature inside the apparatus main body at the time of executing the prediction correction this time.

Furthermore, in the fifth embodiment, the predictive correction unit calculates the color registration deviation amount predicted and corrected by the predictive correction unit as a relative temperature difference from the temperature at the previous predictive correction operation, Of the relative temperature difference from the temperature at the time of executing the previous registration deviation correction operation, the smaller relative temperature difference and the temperature inside the main body of the device at the time of executing the current prediction correction are calculated. is there.

That is, in the fifth embodiment, the IOT main controller 71 as the predictive correction means executes the predictive correction operation for predicting and correcting the color registration deviation amount. The IOT main controller 71 performs the predictive correction operation. As the reference temperature when executing the above, the temperature when the previous prediction correction operation is executed is not used, instead of using the temperature inside the apparatus main body when the registration deviation correction operation execution unit is executed. Is configured to use.

More specifically, in the fifth embodiment, downtime occurs in which the color image forming apparatus cannot execute the color image forming operation and wasteful consumption of toner is increased. The number of registration misregistration correction operations is reduced, and the color misregistration misregistration amount is suppressed as much as possible only by performing prediction correction based on temperature.

FIG. 33 shows a predictive correction operation based on temperature when the machine operation (power-on or print job etc.) and non-operation (power-off or low power mode etc.) are repeated after executing the registration deviation correction operation. It shows how the temperature inside the machine changes and the change in color registration deviation when executed.

In FIG. 33, when the registration deviation correction operation accompanying the formation and detection of the color registration deviation detection pattern is executed and the temperature (absolute temperature) in the apparatus is A, the registration deviation is detected. It is assumed that the color registration deviation is the reference deviation state (ideally, the color registration deviation is zero) in the absolute temperature state A in which the correction operation is executed.

At this time, the IOT main controller 71
In the same manner as in the above-described embodiment, T1 and T3 are set as the condition temperatures at the time of starting the next prediction correction with reference to the in-machine temperature T0 when the absolute temperature state is A. The set temperatures of T1 and T3 are specified in consideration of the allowable amount of color registration deviation.

Next, when a color image is formed in the color image forming apparatus and the temperature inside the apparatus reaches the set temperature T1 (temperature state B), as shown in FIG.
The T main controller 71 executes the first prediction correction operation (prediction correction operation 1). At this time, the color registration deviation is reduced from the color registration deviation state B1 to the color registration deviation state B2 by executing the predictive correction operation.
Further, the IOT main controller 71 sets, for example, T2 and T0 as the condition temperatures for starting the next prediction correction when the prediction correction operation 1 is executed. Where I
The OT main controller 71 determines the temperature T0 when the registration shift correction is executed last time and the internal temperature (absolute temperature) of this time.
Based on T1, T2 and T0, which are condition temperatures for starting the next prediction correction, are set.

When the temperature inside the machine of the color image forming apparatus further rises and the temperature inside the machine reaches T2 to reach the temperature state C, the IOT main controller 71 executes the second predictive correction operation (predictive correction operation 2 ), The color registration shift state is reduced from the color registration shift state C1 to the color registration shift state C2.

Next, consideration will be given to predictive correction based on the temperature when the color image forming apparatus becomes in the operating state after the non-operating state continues for a long time.

As described above, the non-operating state is a state in which there is no factor for increasing the temperature inside the machine like the power-off or stop power mode, and the temperature inside the machine is lower (close to the ambient environment temperature outside the device). State), and the operating state means a state in which the machine temperature rises, such as power-on or print job.

The lower limit value of the starting condition temperature of the next predictive correction operation set after executing the predictive correction operation 2 as described above is, for example, T1, but in the non-operating state, the control device is generally not energized. Since the predictive correction operation is not executed, the predictive correction operation is executed immediately after the operation state is entered. However, if the predictive correction can be performed even in the non-operating state, such as when the control device is in the energized state, the predictive correction may be performed in the non-operating state.

Let T3 be the in-machine temperature immediately after the operation state in which the predictive correction is executed. At this time, based on the relative temperature difference between the temperatures T2 and T3 at the previous predictive correction operation and the in-machine temperature T3. Predict the color registration shift amount,
Correct the amount.

However, as described above, in the predictive correction based on the temperature, the characteristic of the absolute temperature vs. color registration deviation as shown in FIG. 22A is stored in advance as a table or an arithmetic expression to calculate the correction amount. is doing. These predicted correction amounts are only approximate values (or approximate expressions), and are also values or arithmetic expressions that do not take into consideration variations in device-individual differences between machines. Therefore, in the predictive correction, as shown in FIG. 33, inevitably, an error occurs as compared with the registration deviation correction operation (feedback) that accompanies the actual formation and detection of the color registration deviation detection pattern.

This error is caused by repeating the predictive correction operation a plurality of times without executing the registration deviation correction operation associated with the formation and detection of the color registration deviation detection pattern, or when the error due to the relative temperature change is large. , And grows accordingly.
Specifically, the difference between the color registration deviation state A in which the registration deviation correction operation of FIG. 33 is executed and the color registration deviation state C2 in which the prediction correction operation is executed is an error due to the prediction correction operation.

Therefore, in order to reset the accumulated error in the prediction correction operation, in the vicinity of the temperature during the registration deviation correction operation, the temperature during the registration deviation correction operation is used as a reference, not the temperature during the previous prediction correction operation. As the above, it is better to perform the predictive correction based on the relative temperature difference between the temperature at the time of the registration shift correction operation and the temperature inside the apparatus main body at the time of executing the current predictive correction to calculate the color registration shift amount.

In the fifth embodiment, the color registration state D
In the predictive correction of No. 1, the amount of color registration deviation that occurs when the in-machine temperature changes from T0 to T3 is predicted, and correction is performed by updating the correction value (setting value) after the registration deviation correction operation. That is, when repeating the predictive correction operation multiple times,
The temperature at the time of executing the next predictive correction operation may be determined based on the temperature at the previous predictive correction operation, but the temperature inside the machine has changed significantly, such as when the non-operation state has continued for a long time. In this case, compare the relative temperature difference between the temperature during the previous prediction correction operation and the current prediction correction operation with the temperature during the previous registration deviation correction operation and the relative temperature difference between the current prediction correction operation. Then, select the one with the smaller temperature difference. And
If the relative temperature difference between the previous registration deviation correction operation and the current prediction correction operation is smaller, the temperature for the next prediction correction is determined based on the temperature difference.

The color registration correction value (setting value) immediately before the predictive correction operation 3 is a value that has been updated (set) in the previous predictive correction operation 2, and is the registration shift required in the predictive correction operation 3. The correction value (setting value) after the correction operation needs to be stored in a non-volatile memory such as NVM. Here, the correction value (setting value) after the registration deviation correction operation is used to grasp the color registration deviation state at the time of registration deviation correction. It is also possible to store the color registration deviation amount of, and add it to the color registration deviation amount predicted during the prediction correction operation to newly calculate a correction value (setting value). That is, when the predictive correction operation is executed, the color registration deviation amount in the previous or previous registration deviation correction operation is taken into consideration, and the color registration deviation amount to be predicted in the current predictive correction operation is added. You may comprise so that a correction value (setting value) may be newly calculated by performing calculation.

Next, the predicted temperature correction operation 4 is executed even when the in-machine temperature reaches the start condition temperature T4 of the next predicted correction operation set after the predicted correction operation 3. The in-machine temperature T4 at this time is closer to the temperature T0 at the time of the registration deviation correction operation than the temperature T3 at the time of the previous predictive correction operation 2. At this time as well, as described in the processing in the predicted temperature correction operation 3, the temperature T0 at the registration deviation correction operation, which is a close value, is used instead of the temperature T3 at the previous prediction correction operation to correct the registration deviation correction. It is better to predict and correct the color registration deviation amount due to the temperature change in the machine from T0 to T4 with reference to the time of operation. By doing so, the error due to the prediction correction can be reduced.

Since the predictive correction operation 5 shown in FIG. 33 moves away from the temperature T0 during the registration deviation correction operation, the same correction as the predictive correction operations 1 and 2 described above may be performed.

As another method, in the calculation of the correction value (setting value) during the prediction correction, the reference may always be the temperature during the registration deviation correction operation. At this time, the start condition of the predictive correction operation is specified by the temperature specified by the temperature during the registration deviation operation immediately after the registration deviation correction operation and by the prediction correction operation temperature after the prediction correction operation is executed. The temperature may be used, or the start condition temperature for predictive correction may be defined in multiple stages by always using the reference of the start condition as the temperature at the time of registration deviation correction. For example, as the start condition temperature of the predictive correction operation,
(T0-7) ° C / (T0-4) ° C / (T0 + 5) ° C /
In the case where the temperature is increased in multiple stages such as (T0 + 11) ° C., the first prediction correction operation is executed at (T0 + 5) ° C., and when the temperature further rises to (T0 + 11) ° C., the second prediction is performed. It may be configured to execute the correction operation.

The other structure and operation are the same as those in the first embodiment, and the description thereof will be omitted.

Sixth Embodiment In the sixth embodiment, the predictive correction means is configured to execute predictive correction each time an image is formed on a recording medium.

Further, in the sixth embodiment, the predictive correction means predicts the color registration deviation amount each time an image is formed on the recording medium, and the predicted value of the color registration deviation amount is a predetermined deviation amount. The prediction correction may be executed only when it exceeds.

Further, in the sixth embodiment, the predictive correction means may be configured to execute the predictive correction each time the color image forming apparatus is activated.

Furthermore, in the sixth embodiment, the predictive correction unit predicts the color registration deviation amount each time the color image forming apparatus is activated, and the predicted value of the color registration deviation amount is a predetermined deviation amount. The prediction correction may be executed only when it exceeds.

Up to this point, the IOT main controller 71 as the predictive correction means has described an example in which the start condition of the predictive correction based on the temperature is defined by the temperature and the color registration deviation amount due to the temperature change amount is predicted and corrected. However, the execution timing of the predictive correction may be defined and executed irrespective of the temperature or in combination with the predictive correction of the temperature depending on the operating state of the image forming apparatus.

That is, in the sixth embodiment, for example, in the color image forming apparatus, each time image formation (page) is performed, or when the machine is started (power on / polygon mirror operation start / return from low power mode). Time)
Each time, the predictive correction means is always configured to execute the predictive correction operation.

At this time, the correction amount is calculated by predicting the color registration deviation amount from the relative temperature and the absolute temperature of the temperature at the time of the previous registration control operation or the prediction correction by the temperature and the current temperature,
It is configured to calculate the correction value (setting value).

By this operation, the predictive correction operation of the color registration deviation is always executed, which is more effective than the operation of the color registration deviation correction (prediction correction) by setting the start condition with the allowable deviation amount described above. It is possible to reduce the registration shift of the item. In particular, it is effective when the operation speed of the IOT main controller 71 as the predictive correction means is high.

At this time, if the temperature change amount is small, the predicted shift amount and the correction amount corresponding thereto are also small. A certain specified value (allowable amount) is set, and if the deviation amount or the correction amount exceeds the specified value, the correction is executed. If the deviation amount or the correction amount is within the specified value, the correction is not performed. It may be configured to. This is particularly effective when the image output is delayed due to the prediction operation depending on whether the operation speed of the control circuit is fast or slow.

The other structure and operation are the same as those in the first embodiment, and the description thereof will be omitted.

Seventh Embodiment FIG. 34 shows a seventh embodiment of the present invention. The same parts as those in the first embodiment will be designated by the same reference numerals. , A prediction correction unit that predicts and corrects the color registration deviation amount in a plurality of image forming units, and the prediction correction unit forms a color image each time a predetermined time elapses after the color image forming apparatus is started. The color registration shift amount is predicted and corrected based on the integrated start-up time of the apparatus. Note that, in FIG. 34, the two black circles are shown separately in the upper and lower parts for convenience, but the upper black circle indicates the same temperature as the lower black circle.

Further, in the seventh embodiment, after the predictive correction means starts the color image forming apparatus, each time an image is formed on a predetermined number of recording media, the accumulated recording of the color image forming apparatus is carried out. The color registration misregistration amount may be predicted and corrected based on the number of media.

That is, in the seventh embodiment, when the color registration deviation characteristic does not depend on the reading temperature of a specific temperature sensor, the predictive correction operation is executed at a predetermined time interval or every output number of sheets. There is.

More specifically, in the case of the ROS 14 and the fixing device 37 shown in FIG. 3 and the ROS 230 and the fixing device 270 shown in FIG. 26, when the polygon motor for rotating the polygon mirror of the ROS 14 or ROS 230 is started,
Alternatively, when the fixing device 37 or the fixing device 270 is activated (when the temperature rises), as shown in FIG. 34, the change in the color registration deviation due to the temperature rise characteristic in the machine causes a change in the color registration for one temperature sensor reading temperature value. May deviate from the characteristics.
This is because the temperature of a specific portion (polygon motor or fixing device) greatly rises when the polygon motor of the ROS 14 or ROS 230 is started or when the fixing device 37 or the fixing device 270 is started.

Therefore, the above-mentioned ROS 14 and ROS 23
0 polygon motor, or fixing device 37 or fixing device 27
When the image forming member is present near 0, the image forming member is affected by the temperature rise of a specific part, and as shown in FIG. The color registration characteristic with respect to the reading temperature value of the temperature sensor may deviate from the color registration characteristic.

The temperature sensor (environmental sensor) has a relatively stable color registration deviation change amount with respect to the reading temperature value, and has a high sensitivity of color registration change ("temperature change amount /
It is common to install it at a specific place inside the machine (where the amount of change in unit color registration is large). However, it may be difficult to cover all cases of the temperature distribution inside the machine with one temperature sensor (environmental sensor). For example, the above ROS
14 or the temperature change at the time of starting the polygon mirror of the ROS 230, there is a case where the color registration deviation characteristic with respect to the reading value of one sensor is deviated. In other words, when the temperature sensor is installed at a location distant from the ROS 14 or ROS 230, the ROS 14 or ROS 23 concerned.
This is the case where it is not possible to detect the temperature change inside the machine due to the temperature rise of 0.

FIG. 34 shows changes in absolute temperature and color registration deviation at this time. After a certain time (area A in the figure) immediately after the polygon mirror is started, for example, when 100 to 500 sheets are continuously printed,
As shown in the upper graph of FIG. 4, there is a change in the temperature inside the machine read by the temperature sensor and a change in the color registration deviation in which another characteristic is added to the change characteristic in the color registration (the shaded portion in FIG. 34). Then, after the polygon mirror is activated and a certain time has elapsed, the color registration temperature characteristic curve with respect to the in-machine temperature is returned.

Therefore, in the period of the area A, not only the color registration deviation prediction correction due to temperature but also the deviation amount obtained by adding the color registration deviation predicted from the polygon motor start time may be corrected. Although the color registration is predicted in the time after the polygon motor is started, the number of output images may be used if the polygon mirror is started when the image formation is started. Further, although the color registration deviation prediction correction in a certain period after the polygon motor is started has been described here, the same cause may be considered as the fixing device 37 or the fixing device 270.
Even at the start-up (when the temperature rises), the color registration deviation prediction correction may be performed according to the time or the number of output images.

At this time, the IOT main controller 71 as the predictive correction means performs the predictive correction operation every time a predetermined time elapses from the start time of the polygon motor or an image is formed on a predetermined number of recording media. It may be executed, but here, the predetermined time or the predetermined number of sheets does not have to be a constant value, and as shown in FIG. 34, there is a region where the color registration deviation abruptly changes from the starting time of the polygon motor. In this area, the predictive correction may be executed at a constant small time or in the number of sheets, and thereafter, in the area where the color registration deviation is substantially flat, the predictive correction may be executed in a large time or the number of sheets. .

The other structure and operation are the same as those in the first embodiment, and the description thereof will be omitted.

In the above embodiment, the structure in which the color registration deviation amount is predicted and the deviation amount is corrected has been described. However, the correction amount for correcting the color registration deviation amount without predicting the color registration deviation amount is calculated. May be predicted and calculated and corrected.

[0201]

As described above, according to the present invention, it is possible to efficiently perform the registration control operation for correcting the color registration deviation caused by the temperature rise in the apparatus main body, and thereby the image forming operation is performed. Color image formation that enables reduction of so-called downtime, reduction of toner consumption for forming registration control patch, reduction of load on cleaning member, and reduction of waste toner recovery capacity. A device can be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a tandem type digital color printer as a color image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a control circuit of a tandem printer as a color image forming apparatus according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram showing a tandem type digital color printer as a color image forming apparatus according to the first embodiment of the present invention.

FIG. 4A and FIG. 4B are explanatory diagrams showing magnification shifts in the main scanning direction.

5A and 5B are explanatory diagrams showing margin shifts in the main scanning direction, respectively.

FIGS. 6A and 6B are explanatory diagrams showing skew deviations.

FIG. 7A and FIG. 7B are explanatory diagrams respectively showing margin shifts in the sub-scanning direction.

FIG. 8 is an explanatory diagram showing periodic fluctuations in the sub-scanning direction.

FIG. 9 is an explanatory diagram showing periodic fluctuations in the main scanning direction.

FIG. 10 is an explanatory diagram showing a color registration shift due to various factors.

FIG. 11 is a configuration diagram showing an arrangement of a color registration shift detection pattern and a detection unit.

FIG. 12 is an explanatory diagram showing a color registration shift detection pattern.

FIG. 13 is an explanatory diagram showing a pattern for detecting color registration deviation.

FIG. 14 is a perspective configuration diagram showing a detection unit for a color registration shift detection pattern.

FIG. 15 is an explanatory diagram showing a method for detecting a pattern for detecting color registration deviation.

16 (a) to 16 (c) are explanatory views showing a main scanning coarse margin correction, a sub-scanning coarse margin correction, and a skew correction method, respectively.

17 (a) and 17 (b) are explanatory views respectively showing a main scanning fine margin correction, a sub-scanning fine margin correction, and a skew correction method.

18 (a) to 18 (c) are explanatory views showing methods of magnification balance deviation and magnification balance correction, respectively.

FIG. 19 is a waveform diagram showing each clock signal used for magnification balance correction.

FIG. 20 is an explanatory diagram showing a method for correcting pixel positions in the main scanning direction and the sub scanning direction.

FIG. 21 is a flowchart showing the operation of the color image forming apparatus according to the first embodiment of the present invention.

22A and 22B are a graph showing a color registration characteristic curve and a table showing a temperature range based on the graph.

23 (a) and 23 (b) are a graph showing a color registration characteristic curve and a correction parameter based on the graph in Embodiment 2 of the present invention.

FIG. 24 is a graph showing a function approximating a color registration characteristic curve used for controlling the color image forming apparatus according to the third embodiment of the present invention.

FIG. 25 is a graph showing a function approximating a color registration characteristic curve used for controlling the color image forming apparatus according to the third embodiment of the present invention.

FIG. 26 is a schematic configuration diagram showing a tandem type digital color printer as a color image forming apparatus according to Embodiment 4 of the present invention.

FIG. 27 is an explanatory diagram showing a pattern for detecting color registration deviation.

FIG. 28 is a cross-sectional configuration diagram showing a sensor for detecting a color registration shift detection pattern.

FIG. 29 is an explanatory diagram showing a sensor for detecting a color registration shift detection pattern.

FIG. 30 is a schematic configuration diagram showing another configuration example of a tandem type digital color printer as a color image forming apparatus according to the first embodiment of the present invention.

FIG. 31 is a configuration diagram showing a conventional color image forming apparatus.

FIG. 32 is a perspective configuration diagram showing a pattern used for registration deviation in a conventional color image forming apparatus.

FIG. 33 is a graph showing the operation of the color image forming apparatus according to the fifth embodiment of the present invention.

FIG. 34 is a graph showing an operation of the color image forming apparatus according to the seventh embodiment of the present invention.

[Explanation of symbols]

1: Printer body, 13K, 13Y, 13M, 13C:
Image forming unit, 14: ROS, 25: intermediate transfer belt, 50: pattern for detecting color registration deviation, 60: detection means, 71: IOT main controller (prediction correction means).

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/16 G03G 15/16 21/14 21/00 372 (72) Inventor Kosuke Kubota 3-7 Fuchu, Iwatsuki City, Saitama Prefecture No. 1 F-term in Fuji Xerox Co., Ltd. (reference) 2H027 DA11 DE07 EA18 EB04 EC03 ED04 EE02 EF06 EF09 ZA07 2H200 FA01 FA16 GA04 GA06 GA12 GA16 GA23 GA34 GA47 GB12 GB25 HA12 HB03 JA02 JB06 JB50 JC04 JC20 P16 PA18 PA18 PA18 PA18 PA18 PB27 PB39 2H300 EB04 EB07 EB12 EC02 EC05 EC15 ED02 ED05 ED07 ED12 EF02 EF03 EF06 EF09 EG03 EH01 EH16 EH26 EH34 EH35 EH36 EJ09 RR03 Q25 RR40 Q38 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q25 Q40 Q40

Claims (18)

[Claims] 1. A plurality of image forming units for forming images of different colors are provided, and images of different colors formed by the plurality of image forming units are directly or through an intermediate transfer member on a recording medium. In a color image forming apparatus that forms a color image by transferring, based on the temperature inside the apparatus main body detected by the temperature detecting unit and the temperature detecting unit that detects the temperature inside the color image forming apparatus main body, A color image forming apparatus comprising: a prediction correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units. 2. The color image forming apparatus according to claim 1, wherein the predictive correction unit has a constant temperature interval according to a detected value of the temperature inside the apparatus main body detected by the temperature detection unit. A color image forming apparatus, which executes a predictive correction operation for predicting and correcting a color registration deviation amount. 3. The color image forming apparatus according to claim 1, wherein the predictive correction unit has a temperature interval that changes according to a detected value of the temperature inside the apparatus main body detected by the temperature detection unit. A color image forming apparatus, which executes a predictive correction operation for predicting and correcting a color registration deviation amount. 4. The color image forming apparatus according to claim 2 or 3, wherein the color registration deviation amount is predicted according to a detected value of each temperature in the apparatus main body detected by the temperature detecting means. A color image forming apparatus comprising at least one predictive correction table for correction. 5. The color image forming apparatus according to claim 2 or 3, wherein the color registration deviation amount is predicted according to a detected value of each temperature inside the apparatus main body detected by the temperature detecting means. A color image forming apparatus comprising at least one predictive correction calculation formula for correction. 6. The color image forming apparatus according to any one of claims 1 to 5, each time a prediction correction operation of a color registration deviation amount is executed, a next color registration deviation amount prediction correction operation is executed. A color image forming apparatus, wherein an upper limit value and a lower limit value of a temperature interval are determined. 7. The color image forming apparatus according to claim 1, wherein the color registration deviation detecting pattern formed by each of the image forming units is transferred onto the same pattern detecting member to detect the pattern. Detects the color registration deviation detection pattern transferred onto the printing member,
A registration deviation correction operation executing means for executing a color registration deviation correction operation is provided, and the predictive correction means performs at least one color registration deviation amount while the registration deviation correction operation is executed by the registration deviation correction operation executing means. A color image forming apparatus, characterized in that the predictive correction operation is performed. 8. The color image forming apparatus according to claim 7, wherein the predictive correction means is based on a temperature inside the apparatus main body when the registration deviation correction operation is executed by the registration deviation correction operation execution means. The color image forming apparatus is characterized in that the temperature at which the predictive correction operation is executed is set. 9. The color image forming apparatus according to claim 7, wherein the predictive correction unit executes a previous predictive correction operation as a reference temperature when the predictive correction operation is executed by the predictive correction unit. A color image forming apparatus characterized by using the temperature at the time. 10. The color image forming apparatus according to claim 7, wherein the predictive correction unit sets a color registration deviation amount predicted and corrected by the predictive correction unit as a temperature at a previous predictive correction operation. The color image forming apparatus is characterized in that it is calculated based on the relative temperature difference of the above and the temperature inside the apparatus main body at the time of executing the prediction correction this time. 11. The color image forming apparatus according to claim 7, wherein the predictive correction unit predicts a color registration misalignment amount predicted and corrected by the predictive correction unit when a previous misregistration correction operation is executed. A color image forming apparatus, which is calculated based on a relative temperature difference with respect to a temperature and a temperature inside the apparatus main body at the time of executing the prediction correction this time. 12. The color image forming apparatus according to claim 7, wherein the predictive correction unit predicts a color registration deviation amount predicted and corrected by the predictive correction unit as a temperature at a previous predictive correction operation. Calculated based on the smaller relative temperature difference of the relative temperature difference of the previous registration correction operation and the relative temperature difference of the previous registration deviation correction operation, and the temperature inside the apparatus main body at the time of the predicted correction execution this time. A color image forming apparatus characterized by the above. 13. A plurality of image forming units for forming images of different colors are provided, and images of different colors formed by the plurality of image forming units are directly or through an intermediate transfer member on a recording medium. In a color image forming apparatus that forms a color image by transferring, a prediction correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided, and the prediction correction unit is an image on a recording medium. A color image forming apparatus, characterized in that prediction correction is executed each time a sheet is formed. 14. A plurality of image forming units for forming images of different colors are provided, and images of different colors formed by the plurality of image forming units are directly or through an intermediate transfer member on a recording medium. In a color image forming apparatus that forms a color image by transferring, a prediction correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided, and the prediction correction unit is an image on a recording medium. A color image forming apparatus, which predicts a color registration deviation amount each time an image is formed, and executes prediction correction when a predicted value of the color registration deviation amount exceeds a predetermined deviation amount. 15. A plurality of image forming units for forming images of different colors are provided, and images of different colors formed by the plurality of image forming units are directly or through an intermediate transfer member on a recording medium. In a color image forming apparatus that forms a color image by transferring, a prediction correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided, and the prediction correction unit includes the color image forming apparatus. A color image forming apparatus, characterized in that prediction correction is executed each time the apparatus is activated. 16. A plurality of image forming units for forming images of different colors are provided, and images of different colors formed by the plurality of image forming units are directly or through an intermediate transfer member on a recording medium. In a color image forming apparatus that forms a color image by transferring, a prediction correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided, and the prediction correction unit includes the color image forming apparatus. A color image forming apparatus, which predicts a color registration deviation amount each time it is activated, and executes prediction correction when a predicted value of the color registration deviation amount exceeds a predetermined deviation amount. 17. A plurality of image forming units for forming images of different colors are provided, and the images of different colors formed by the plurality of image forming units are directly or through an intermediate transfer member on a recording medium. In a color image forming apparatus that forms a color image by transferring, a prediction correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided, and the prediction correction unit is the color image forming apparatus. A color image forming apparatus, characterized in that a predictive correction of a color registration deviation amount is executed based on an integrated starting time of the color image forming apparatus every time a predetermined time has elapsed after starting. 18. A plurality of image forming units for forming images of different colors are provided, and the images of different colors formed by the plurality of image forming units are directly or through an intermediate transfer member on a recording medium. In a color image forming apparatus that forms a color image by transferring, a prediction correction unit that predicts and corrects a color registration deviation amount in the plurality of image forming units is provided, and the prediction correction unit is the color image forming apparatus. A color image is characterized in that, every time an image is formed on a predetermined number of recording media after the start of the Forming equipment.