JPH11202589A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately, stably and exactly perform the registration of a transfer body with simple constitution by adjusting timing to superimpose each color image on a transfer means based on timing to detect a pattern image. SOLUTION: Detection sensors 232a and 232b detect two pattern images (Bk and Bk) formed at the same timing in a main scanning direction by an image forming part being reference, first. Next, the pattern image where the timing that the sensor 232a detects the pattern image (Bk) formed by the image forming part being the reference coincides with the timing that the sensor 232b detects the pattern image (Y1, Y2 and Y3) formed by an image forming part for performing adjustment is decided. In the image forming part for performing the adjustment, an image write-in start timing for a Y image recording part is set by deciding in what timing the pattern image is formed by using information from the counter of a decision control circuit 440, etc.

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 having a recording section for color-separating and reading image information of, for example, a color original, and recording and reproducing a read image based on the read color-separated image information of the original. More specifically, the present invention relates to an image forming apparatus such as a digital copying machine, and more specifically, reproduces an image of each color based on image information of each color that has been color-separated, and reads the reproduced images of each color by accurately overlapping each other. The present invention relates to an image forming apparatus that faithfully reproduces an image.

[0002]

2. Description of the Related Art In a conventional image forming apparatus for forming a color image, for example, a color digital copying machine, a predetermined image processing is performed on a color separation image of a document input from a scanner or the like, and then a printer is used. A color image is output from a unit (printing unit), and the color original image after color separation is recorded and reproduced for each color, and is reproduced as a color image by superimposing on a predetermined recording medium.

However, when the color separation images of the respective colors are superimposed, if the color separation images of the respective colors are not accurately superimposed, a color shift of the image occurs, and the color original image originally has The feature (image quality) will not be faithfully reproduced.

Therefore, a registration control unit is mounted so that images of respective colors are accurately overlapped on an intermediate transfer member or the like, and registration correction is periodically performed when the apparatus is in a predetermined state, so that an image close to the original image is obtained. Techniques for outputting expressions have been developed, and are disclosed in JP-A-63-43172,
JP-A-63-271275, JP-A-6-2389
No. 54, JP-A-4-147280 is known.

First, in JP-A-63-43172, a measurement pattern image 28B for each color is placed on a transfer / conveyance belt 21.
K, 28Y, 28M, 28C are formed, and the measurement pattern images 28BK, 28Y, 28M,
A configuration in which the passage of 28C is detected by the reflection sensor 27, and the deviation from the set value of the measurement pattern images 28BK, 28Y, 28M, 28C for each color is calculated to control the writing timing in the image forming unit for each color. Has been proposed.

Further, as a method of calculating the deviation from the set value,
Measurement pattern images 28BK, 28Y, 28M for each color
28C, after the reflective sensor 27 detects the measurement pattern image 28BK formed by the black image recording unit,
A technique is disclosed in which the timing until each of the other measurement pattern images 28Y, 28M, and 28C is detected is counted, thereby detecting a position shift of image writing in the image forming unit of each color.

In Japanese Patent Application Laid-Open No. 63-271275, measurement pattern images 34 and 35 are formed on the transfer / conveying belt 6a by an image forming station for each color, and the measurement pattern images (image register mark portions) are formed. The sensors (CCD) 14 and 15 detect the passage of 34 and 35, and calculate the image forming position shift in the image forming station of each color in the measurement pattern images 34 and 35 to calculate the image forming position for each color in the image forming unit. A configuration for adjusting the writing timing or the image writing position has been proposed.

As a method of calculating the image forming position shift at each image forming station, the shift of the detection timing of the measurement pattern images 34 and 35 for each color by the sensors 14 and 15 is counted, respectively. It is shown that a positional deviation of image writing is detected.

In Japanese Patent Application Laid-Open No. Hei 6-238954, a color image forming apparatus is provided with a plurality of colors in which another color is sequentially shifted by one dot or several dots in the vertical and horizontal (main and sub scanning) directions with respect to an arbitrary color. Is stored, and this pattern image is output from the forming apparatus.
If a group number of a timing at which a pattern image (line image) of another color matches a pattern image (line image) of an arbitrary color in the output pattern image is input, the input group is input. A technique has been proposed in which the image writing timing in each color image forming unit is adjusted based on the number.

Further, Japanese Patent Application Laid-Open No. 4-147280 discloses a detecting means for detecting a specific pattern output from an exposure apparatus, a means for calculating a positional shift of the specific pattern between the respective exposure apparatuses, It has control means to control the position of each exposure device based on the shift, and the exposure start point shifts when performing multiple latent image formations repeatedly without positioning multiple exposure devices with strict mechanical accuracy And a technique that can prevent color shift.

[0011]

As described above, first, in JP-A-63-43172, the measurement pattern images 28BK, 28Y,
28M and 28C are formed, and the passage of the measurement pattern images 28BK, 28Y, 28M and 28C for each color is detected by the reflection sensor 27, and the measurement pattern images 28BK, 28Y, 28M and 28C for each color are detected. A configuration has been proposed in which a deviation from a set value (a count value from the detection of a black image pattern image to the detection of an image pattern of another color) is calculated to control the writing start timing in the image forming unit for each color. Since the displacement of the image writing in the image forming unit can be detected, it is effective in that the adjustment can be automatically performed without performing the adjustment by the component accuracy or the assembly.

In Japanese Patent Application Laid-Open No. 63-271275, the measurement pattern images 34 and 35 are formed on the transfer / conveying belt 6a by an image forming station for each color, and the measurement pattern images (image register mark portions) are formed. The sensors (CCD) 14 and 15 detect the passage of 34 and 35, and calculate the image forming position shift in the image forming station of each color in the measurement pattern images 34 and 35 to calculate the image forming position for each color in the image forming unit. A configuration that adjusts the writing start timing or the image writing position has been proposed, and is effective in that positional deviation between images can be corrected extremely easily.

Further, Japanese Patent Application Laid-Open No. 4-147280 discloses a detecting means for detecting a specific pattern output from an exposure apparatus, a means for calculating a positional shift of each specific pattern between the respective exposure apparatuses, It has control means to control the position of each exposure device based on the shift, and the exposure start point shifts when performing multiple latent image formations repeatedly without positioning multiple exposure devices with strict mechanical accuracy This is effective in preventing color misregistration.

However, in the technical contents described in these publications, there is a case where accurate image position shift is not performed and a faithful color image expression cannot be obtained. Since there is drive unevenness for each of the formation part and the image transfer part), the drive unevenness may affect each of the steps of forming a plurality of measurement pattern images or detecting the formed plurality of pattern images. As a result, the detection timing value (for example, a count value) of each pattern image detected by the detection sensor is affected, and it may not be possible to appropriately correct the image position shift.

In Japanese Patent Application Laid-Open No. Hei 6-238954, a color image forming apparatus is provided with a plurality of colors in which another color is sequentially shifted by one dot or several dots in the vertical and horizontal (main and sub scanning) directions with respect to an arbitrary color. Is stored, and this pattern image is output from the forming apparatus.
If a group number of a timing at which a pattern image (line image) of another color matches a pattern image (line image) of an arbitrary color in the output pattern image is input, the input group is input. This is effective in that the image writing timing in the image forming unit for each color can be adjusted based on the numbers, and can be easily adjusted at the time of manufacturing or when replacing parts such as drums.

However, according to the publication, the output (printed) test pattern is confirmed by human eyes,
The configuration is such that the result is input by a person who has confirmed the result, so that only an experienced operator can adjust the image quality, and there has been a problem that an input error causes useless printing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide an image forming apparatus capable of accurately, stably and surely performing registration of a transfer member with a simple configuration. It is to provide a device.

Another object of the present invention is to provide an image forming apparatus which automatically performs registration adjustment and does not impose a burden on a user.

Furthermore, an image forming apparatus is provided which can not only automate but also improve the accuracy of automatic adjustment of registration, and can perform accurate registration adjustment with a simple configuration without providing a special correction process. The purpose is to do.

[0020]

According to an aspect of the present invention, there is provided an image forming apparatus, comprising: image information input means for inputting color image information for each color component; and an image for each input color image information. A plurality of image forming means, a transfer means for transferring each image formed by the plurality of image forming means, and a pattern image for aligning each image on the transfer means. Pattern image forming means, pattern image detecting means for detecting the pattern image, and transfer means for transferring each color image formed by the plurality of image forming means based on the timing of detecting the pattern image by the pattern image detecting means. In the image forming apparatus provided with an adjusting unit for adjusting a timing of superimposing the image, the pattern image detecting unit is provided at substantially both ends of the transfer unit with a reference image forming unit. A pattern image repeatedly formed at a predetermined timing and a pattern image formed at a different timing by an image forming unit to be adjusted are formed, and the pattern images are detected at substantially both ends of the transfer unit. Then, the adjusting means comprises first and second detecting means for outputting a detection signal, and the adjusting means attempts to adjust the pattern image repeatedly formed at a predetermined timing by the reference image forming unit. The pattern images formed at different timings by the image forming unit are adjusted so as to be substantially opposed to each other on a line in the main scanning direction of the transfer unit.

According to a second aspect of the present invention, there is provided an image forming apparatus, comprising: image information input means for inputting color image information for each color component;
A plurality of image forming means for forming an image for each input color image information; a transfer means for transferring each image formed by the plurality of image forming means; and a transfer means for transferring each image on the transfer means. Pattern image forming means for forming a pattern image for positioning, pattern image detecting means for detecting the pattern image, and the plurality of pattern images based on detection timing of the pattern image by the pattern image detecting means. In an image forming apparatus provided with adjusting means for adjusting the timing at which each color image formed by the image forming means is superimposed on the transfer means, the pattern image detecting means includes a reference and a reference at substantially both ends of the transfer means. The pattern image repeatedly formed at a predetermined timing by the image forming unit, and the pattern image formed at a different timing by the image forming unit to be adjusted. Together to form pattern images and the respective first for outputting a detection signal when it detects the pattern image substantially at both end portions of the transfer means
And second detection means, wherein the first and second detection means
The distance between each image forming means in the image forming means for each color component and the first output means for outputting the first pattern image for correcting the shift of the detection timing of the detecting means with respect to the main scanning line. And a second output unit for outputting a second pattern image for adjustment.

According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the first pattern image is a visible image having a light reflection characteristic different from the light reflection characteristic of the surface of the transfer means in each image forming section. It is characterized by being formed with an agent.

According to a fourth aspect of the present invention, in the image forming apparatus according to the second aspect, the second pattern image is a visual image having a light reflection characteristic different from the light reflection characteristic of the surface of the transfer means in each image forming section. It is characterized by being formed with an agent.

According to a fifth aspect of the present invention, in the image forming apparatus according to the second aspect, the main scanning in each of the detection units is performed based on a detection signal obtained when the first and second detection units detect the first pattern image. Means for determining the deviation amount of the detection timing with respect to the line as correction data,
When the detection means detects the second pattern image and adjusts the image writing start timing in each image forming unit, the image writing start timing is determined based on the correction data.

According to a sixth aspect of the present invention, in the image forming apparatus according to the second aspect, the pattern image forming means includes first and second pattern image forming means.
After outputting the first pattern image for correcting the detection timing shift of the image detecting means with respect to the main scanning line, the second pattern adjusting means for adjusting the distance between the image forming means in the image forming means for each color component. In addition to outputting a pattern image, when an image writing timing is detected for each image forming unit, the timing is corrected based on a shift amount of a mounting position of the detection unit.

According to a seventh aspect of the present invention, in the image forming apparatus according to the second aspect, after the pattern image forming unit outputs the second pattern image, the first and second image detecting units detect the main scanning line. Outputting a first pattern image for correcting the timing shift, and correcting the timing in consideration of the mounting position shift of the detecting unit after detecting the image writing timing in each image forming unit. I do.

According to an eighth aspect of the present invention, in the image forming apparatus according to the second aspect, the first pattern image is formed by an image forming means serving as a reference, and substantially at both ends on the transfer means in the main scanning direction. In the same positional relationship, the second pattern image is the one formed by the reference image forming unit.
A set of pattern images formed by one pattern image and a plurality of pattern images each having a different forming timing formed by the image forming unit to be adjusted. It is characterized by having the same positional relationship.

According to a ninth aspect of the present invention, in the image forming apparatus according to the second aspect, the first pattern image is formed by an image forming means serving as a reference, and is substantially the same at both ends on the transfer means in the main scanning direction. In the second pattern image, one of the pattern images formed at a predetermined timing by the reference image forming unit and the other formed by the image forming unit to be adjusted have different formation timings. A pattern image comprising a plurality of sets, each of which is one of a plurality of pattern images, wherein substantially the same positional relationship with respect to the main scanning direction is provided at substantially both end portions on the transfer means.

According to a tenth aspect of the present invention, in the image forming apparatus according to the eighth or ninth aspect, the image writing timing adjusting means is based on correction data obtained by detecting the first pattern image by the pattern image detecting means. The present invention is characterized in that the formation timing of the pattern image detected at the same timing in the main scanning direction by the two detection sensors is confirmed, and the image writing start timing in each image forming unit is adjusted.

In the image forming apparatus according to the present invention, the order of the plurality of pattern images formed at different timings based on the pattern image detection signal from the second detecting means is determined. It is characterized by comprising a pattern image detection management means for managing whether or not detection has been performed.

According to a twelfth aspect of the present invention, in the ninth aspect, a plurality of sets of pattern images formed at different timings based on the pattern image detection signal by the first or second detection means are provided. A pattern image detection management means for managing what number is detected.

According to a thirteenth aspect of the present invention, there is provided an image forming apparatus, comprising: image information input means for inputting color image information for each color component; and a plurality of image forming means for forming an image for each input color image information. Means, transfer means for transferring each image formed by the plurality of image forming means, and pattern image forming means for forming a pattern image for alignment of each image on the transfer means, Based on pattern image detection means for detecting the pattern image, based on the timing of detection of the pattern image by the pattern image detection means,
A control unit for controlling a timing of superimposing each color image formed by the plurality of image forming units on the transfer unit, wherein the pattern image forming unit comprises: And a plurality of detection pattern images formed by superimposing one of the second color pattern images, each of which has a different forming timing, and the positional relationship between the first color pattern image and the second color pattern image is a predetermined positional relationship. Is characterized in that a set of pattern images is detected, and image writing timing in the image forming unit is controlled in accordance with the detected set of pattern image information.

According to a fourteenth aspect of the present invention, in the thirteenth aspect, a plurality of sets of detection pattern images are formed on the transfer means along the moving direction of the transfer means, and are formed on the transfer means. The pattern image detecting means is arranged at a predetermined position to detect the detected pattern image.

According to a fifteenth aspect of the present invention, in the fourteenth aspect, based on the pattern image detection signal from the pattern image detection means, the number of pattern images among the plurality of pattern images formed on the transfer means is determined. It is characterized by comprising a pattern image detection management means for managing whether or not detection has been performed.

According to a sixteenth aspect of the present invention, in the image forming apparatus according to the thirteenth aspect, a pattern image of a second color, which is formed by the pattern image forming means and has a different formation timing from a pattern image of a first color serving as a reference. One of the features is that the width of the transfer means in the transport direction is the same.

According to a seventeenth aspect of the present invention, in the image forming apparatus according to the sixteenth aspect, the pattern image detecting means detects a width of a plurality of sets of the detected pattern images, and the width of the detected pattern images detected by the detecting means is equal to or smaller than the detected width. The image writing timing of the image forming unit is controlled on the basis of the smallest one.

In the image forming apparatus according to the present invention, the pattern image forming means may include:
Among image forming means for forming an image for each color component, for each image forming means other than the reference image forming means, a plurality of images having different timings with respect to the pattern image formed by the reference image forming unit. Are sequentially formed.

According to a nineteenth aspect of the present invention, in the image forming apparatus according to the eighteenth aspect, the pattern image forming means forms a plurality of pattern images having the same timing when forming the pattern images at different timings. The detection result is determined based on the detection result of the pattern image.

According to a twentieth aspect of the present invention, in the image forming apparatus according to the eighth, ninth or thirteenth aspect, the pattern image forming means comprises:
Among image forming means for forming an image for each color component, each of the image forming means other than the reference image forming means is paired with a pattern image formed by the reference image forming means at different timings. A plurality of pattern images are formed, and the pattern images at different timings are repeatedly formed until the pattern image detecting means detects a pattern image having a predetermined positional relationship with a reference pattern image. .

According to a twenty-first aspect of the present invention, in the twentieth aspect, when the pattern image detecting means detects a pattern image having a predetermined positional relationship by the pattern image detecting means, the pattern image forming means is activated by another image forming means. The process is characterized by shifting to pattern image formation.

According to a twenty-second aspect of the present invention, in the image forming apparatus according to the twenty-first aspect, even if the pattern image detecting means detects a pattern image having a predetermined positional relationship by the pattern image detecting means, the pattern image forming means has at least one pattern image having a different timing. It is characterized in that a pattern image is formed and a positional relationship with a reference pattern image is detected.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.

Although only the case where the present invention is applied to a color digital copying machine has been described as an embodiment of the present invention, the present invention is not applied only to the present invention, and a plurality of color image information is transferred. It is needless to say that the present invention can be applied to all image forming apparatuses that transfer images to the image forming apparatus.

FIG. 1 is a schematic front sectional view showing the structure of a digital color copying machine 1 which is an image forming apparatus according to an embodiment of the present invention. A document table 11 is provided on the upper surface of the copying machine body 1.
1 and an operation panel (not shown) are provided, and are supported on the upper surface of the document table 111 so as to be openable and closable with respect to the document table 111. An automatic document feeder 112 is mounted. Further, an image reading unit 110 and an image forming unit 210 are configured inside the copying machine main body 1.

First, on the upper surface of the copying machine body 1,
The automatic document feeder 112 mounted on the document feeder 11 is a two-sided automatic document feeder 112 corresponding to a two-sided original. First, the original A is moved so that one side of the original A faces a predetermined position of the original platen 111. The document A is conveyed, and after the image reading on one side is completed, the document A is turned over so that the other side faces at a predetermined position on the document table 111 and conveyed toward the document table 111.

After the reading of the image on both sides of one document is completed, the document is discharged, and the double-sided conveyance operation for the next document is executed. The operation of conveying the document A and the operation of turning over the original are controlled in relation to the operation of the entire copying machine.

Further, in order to read the image of the original A conveyed onto the original platen 111 by the automatic two-sided automatic original feeder 112, the original is moved back and forth in parallel along the lower surface of the original platen 111 below the original platen 111. The original scanning body is arranged.

The original scanning body comprises an exposure lamp 117 for exposing the original image surface and a first mirror 119 for deflecting a reflected light image from the original in a predetermined direction. A first scanning unit 113 which reciprocates in parallel at a predetermined scanning speed, and a second scanning unit 113 which deflects a reflected light image from a document deflected by a first mirror 119 of the first scanning unit 113 further in a predetermined direction. A second scanning unit 114 composed of a second mirror 120 and a third mirror 121, which reciprocates in parallel with the first scanning unit 113 at a constant speed relationship, and a document deflected by the third mirror 121 of the second scanning unit. An optical lens 115 for reducing the reflected light image from the image to form an optical image at a predetermined position, and an optical image reduced by the optical lens to form an optical image. And a photoelectric conversion element 116. which photoelectrically converts and outputs the reflected light image from the document as an electric signal.

The original image information converted into an electric signal by the photoelectric conversion element 116 is further transferred to an image processing unit described later and subjected to predetermined processing as image data.

Next, the image forming section 210 located below the copying machine 1 will be described.
A paper feed mechanism 211 is provided on the lower side of 10.
The sheets stored in the sheet tray 230 are separated one by one and supplied toward the recording unit.

The paper separated and supplied one by one is transferred to a pair of registration rollers 2 disposed in front of the image forming section 210.
The sheet is controlled and conveyed by the printer 12 and is re-conveyed and conveyed at a timing with another image forming section.

Below the image forming section 210, a transfer / conveying belt mechanism 213 extending substantially in parallel is arranged. The transfer / conveying belt mechanism 213 extends between a plurality of rollers such as a driving roller 214 and a driven roller 215. The paper is configured to be electrostatically attracted and conveyed.

Further, a fixing device 217 for fixing the toner image transferred and formed on the sheet onto the sheet is disposed downstream of the transfer / conveying belt mechanism 213. The fixing device 217 passes between the fixing roller nips of the fixing device 217. The discharged sheet is discharged by a discharge roller 219 through a transfer direction switching gate 218 onto a discharge tray 220 attached to an outer wall of the apparatus.

The switching gate 218 selectively switches between discharging the fixed sheet to the outside of the apparatus and re-supplying the sheet to the image forming section again. The sheet whose conveyance direction has been switched toward the copy unit is turned over and then supplied again to the image forming unit via the switchback conveyance path 221.

The driving roller 214 and the driven roller 21
5 and the like, the transfer conveyance belt 216 stretched substantially in parallel.
The first, second, third, and fourth image forming stations Pa, Pb, Pc, and Pd are arranged side by side in the order from the upstream side of the transport path close to the transfer transport belt 216.

The transfer conveying belt 216 is frictionally driven by the drive roller 214 in the direction indicated by the arrow Z in FIG. 1, and carries the transfer material P fed through the paper feeding mechanism 211 as described above. The sheet is sequentially conveyed to image forming stations Pa, Pb, Pc, and Pd.

Each of the image stations Pa, Pb, Pc, and Pd has substantially the same configuration, and the photosensitive drums 222a and 222 are driven to rotate in the direction of arrow F shown in FIG.
b, 222c, and 222d, and a charger 22 for uniformly charging the photosensitive drum is provided around each photosensitive drum.
3a, 223b, 223c and 223d, and a developing device 22 for developing an electrostatic latent image formed on the photosensitive drum
4a, 224b, 224c, and 224d, and a transfer discharger 225 for transferring the developed toner image to the transfer material P
a, 225b, 225c, and 225d, and cleaning means 2 for removing toner remaining on the photosensitive drum
26a, 226b, 226c, and 226d are sequentially arranged along the rotation direction of the photosensitive drum.

Each photosensitive drum 222a, 222
Above b, 222c, and 222d, a semiconductor laser device that emits dot light modulated according to image data, a deflecting device for deflecting light from the semiconductor laser device in the main scanning direction, and a deflecting device A laser beam scanner unit 227a including an f-θ lens for forming an image of the deflected laser beam on the surface of the photoconductor,
227b, 227c, and 227d are provided, respectively.

The laser beam scanner 227a receives a pixel signal corresponding to the yellow component image of the color original image, the laser beam scanner 227b receives a pixel signal corresponding to the magenta component image of the color original image, and the laser beam scanner 227c receives the color signal. A pixel signal corresponding to the cyan component image of the document image is input to the laser beam scanner 227d, and a pixel signal corresponding to the black component image of the color document image is input to the laser beam scanner 227d.

As a result, an electrostatic latent image corresponding to the color-converted original image information is formed on the photosensitive member 222 of each recording unit, and the developing device 227a of each recording unit contains yellow toner and the developing device 227b. Contains the magenta toner, the developing device 227c contains the cyan toner, and the developing device 227d contains the black toner. Reproduced as a toner image.

A paper-suction (brush) charger 228 is provided between the first image forming station Pa and the paper feeding mechanism 211. And the sheet feeding mechanism 211
The first image forming station Pa in a state in which the transfer material P supplied from
To the fourth image forming station Pd without shifting.

On the other hand, a static eliminator (not shown) is provided almost directly above the drive roller 214 between the fourth image station Pd and the fixing device 217. An alternating current for separating the electrostatically attracted transfer material P is applied.

In the color copying machine having the above-mentioned structure, a cut sheet is used as the transfer material P. The transfer material P is sent out from the paper feed cassette and set in the guide of the paper feed mechanism of the paper feed mechanism 211. When supplied, the transfer material P
Is detected by a sensor (not shown), and the sheet is temporarily stopped by the pair of registration rollers 212 according to a detection signal output from the sensor. Then, the transport belt 21 rotating in the arrow Z direction in FIG. 1 at a timing with each of the image stations Pa, Pb, Pc, and Pd.
It is sent to 6 side. At this time, the charging device 22 for suction described above is used.
8, the conveyor belt 216 is charged at a predetermined level, so that the image stations Pa, Pb, Pc, and P
While passing through d, the paper is stably conveyed and supplied.

In each of the image stations Pa, Pb, Pc, and Pd, a toner image of each color is formed by the above-described configuration, and is superposed on the support surface of the transfer material P electrostatically attracted and transported by the transport belt 216. , Fourth
When the image transfer by the image station Pd is completed, the sheet is separated from the conveying belt 216 by the discharging device from the leading end of the sheet and guided to the fixing device 217. Then, the transfer material P on which the toner image is finally fixed is discharged onto the discharge tray 220 from the transfer material discharge port.

(Description of Network System Configuration Including Color Digital Copying Machine) FIG. 2 is a diagram showing a network system configuration centering on the color digital copying machine 1 instead of the color digital copying machine 1 as a stand-alone.

The image information input method includes not only inputting document information from the image reading section 110 of the color digital copying machine 1 but also connecting a personal computer 2, a digital camera 3, a digital video camera 4, a communication portable terminal connected to a network. 5 supports image information input from external devices.

Further, image information can be input from a remote place through the Internet, an intranet, or a rapidly growing communication infrastructure.

Therefore, the digital copying machine which outputs such image information plays an important role as a multi-function printer or a network printer, and in addition to the functions of the digital copying machine, it has an added value from the viewpoint of further use. Is a system configuration that can be provided.

(Circuit Description of Image Processing Unit) Next, the configuration and function of the image processing unit for color image information mounted on the color digital copying machine will be described with reference to FIG. FIG. 3 is a block diagram of the image processing unit included in the color digital copying machine 1.

The image processing section included in the digital copying machine 1 includes an image data input section 40, an image processing section 41, an image data output section 42, a hard disk device or a RAM.
(Random access memory), etc., an image memory 43, a central processing unit (CPU) 44, and an image editing unit 4.
5 and external interface units 46 and 47.

The image data input section 40 is a three-line color CCD 40a capable of reading a black-and-white original or a color original image and outputting line data separated into RGB color components. A shading correction circuit 40b for correcting the line image level, a line matching unit 40c such as a line buffer for correcting a shift of image line data read by the three-line color CCD 40a, and lines of each color output from the three-line color CCD 40a. A sensor color correction unit 40d for correcting the color data of the data, an MTF correction unit 40e for correcting the change in the signal of each pixel so as to have a sharpness, and a gamma correction unit 40f for correcting the brightness of the image to correct the visibility. Etc.

The image processing section 41 includes an image data input section 40
Data generation unit 41a that generates monochrome data from RGB signals that are color image signals input from
(Black and white original) and an input processing unit 41b that converts the RGB signals into YMC signals corresponding to the respective recording units of the recording apparatus and also performs clock conversion, and prints whether the input image data is a character portion or a halftone photograph. An area separation unit 41c that separates each image into YM output from the input processing unit 41a
A black generation unit 41d that performs under color removal processing based on the C signal to generate black, a color correction circuit 41e that adjusts each color of a color image signal based on each color conversion table, and an image that is input based on a set magnification It comprises a zoom processing circuit 41f for converting information into a magnification, a spatial filter 41g, a halftone processing section 41h for expressing gradation such as multi-level error diffusion and multi-level dither, and the like.

Each color image data subjected to the halftone processing is temporarily stored in the image memory 43. The image memory 43 stores 8 bits and 4 colors (32 bits) serially output from the image processing unit 41.
4) hard disk (rotary storage medium) that sequentially receives image data of each bit, temporarily stores the data in a buffer, converts the 32-bit data into 8-bit 4-color image data, and stores and manages the image data for each color. 43a, 4
3b, 43c and 43d.

Since the position of each image station is different, each color image data is temporarily stored in the delay buffer memory 43e (semiconductor memory) of the image memory 43, and the image data is sent to each laser scanner unit by shifting the time. Adjust the timing to prevent color shift.

The image memory 43 further includes an image synthesizing memory 43f for synthesizing a plurality of images.

The image data output section 42 is a halftone processing section 41
h) a laser control unit 42a that performs pulse width modulation based on each color image data from h, a laser scanner unit for each color that performs laser recording based on a pulse width modulation signal corresponding to an image signal of each color output from the laser control unit 42a 42b, 42c, 42d, 42
e.

The central processing unit (CPU) 44 controls an image data input section 40, an image processing section 41, an image memory 43, an image data output section 42, an image editing section 45 to be described later, and external interface sections 46 and 47. Is controlled based on the sequence.

The image editing unit 45 performs a predetermined image editing on the image data once stored in the image memory 43 via the image data input unit 40, the image processing unit 41, or an interface described later. The editing work of the image data is performed by using the image combining memory 43f.

The interface 46 is a communication interface for receiving image data from an external image input processing device (digital camera 3, digital video camera 4, communication portable terminal 5, etc.) provided separately from the digital copying machine 1. Means.

The image data input from the interface 46 is also once input to the image processing section 41 and subjected to color space correction and the like, to a data level that can be handled by the image recording section 210 of the digital copying machine 1. The converted data is stored and managed in the hard disks 43b, 43c, 43d, and 43e.

Further, an interface 47 is a printer interface for inputting image data created by the personal computer 2, and a monochrome or color FAX for receiving image data received by FAX.
Interface. The image data input from the interface 47 is already a CMYK signal, is subjected to a halftone process 41h, and is stored and managed in the hard disks 43b, 43c, 43d and 43e of the image memory 43.

(Explanation of Control Structure of Entire Digital Copier)
FIG. 4 is a diagram showing a state in which the operation of each unit of the entire apparatus of the digital copying machine 1 is managed by a central control unit (CPU) 44.

The image data input unit 40, the image processing unit 41,
The details of the image memory 43, the image data output unit 42, and the central processing unit (CPU) 44 are as described with reference to FIG.

The central processing unit 44 includes, in addition, RADF,
Each of the drive mechanism units constituting the digital copying machine 1 such as a scanner unit and a laser printer unit is managed by sequence control, and a control signal is output to each unit.

Further, an operation board unit 48 comprising an operation panel is connected to the central processing unit 44 so as to be able to communicate with each other, and a control indicating the contents of the copy mode set and inputted by the operator in response to the operation of the operation panel 75. The signal is transferred to the central processing unit 44 to control the entire digital color copying machine 1 to operate according to the set mode.

Also, control signals indicating various operating states of the digital color copying machine 1 are transferred from the central processing unit 44 to the operation board unit 48, and the operation board unit 48
On the side, the operation state is displayed on the display unit or the like so as to indicate to the operator what state the apparatus is currently in by the control signal.

(Explanation of Operation Panel) FIG. 5 shows an operation panel 75 in a color digital copying machine.

At the center of the operation panel 75, a touch panel liquid crystal display device 6 is arranged, and various mode setting keys are arranged therearound.

On the screen of the touch panel liquid crystal display device 6, there is a screen switching instruction area for constantly switching to a screen for selecting an image editing function, and when this area is directly pressed with a finger, various image editing functions are selected. A list of various editing functions is displayed on the liquid crystal screen so that the operator can set an editing function by touching a region where a desired function is displayed with a finger from the displayed various editing functions.

The various setting keys arranged on the operation panel will be briefly described. Reference numeral 7 denotes a dial for adjusting the brightness of the screen of the liquid crystal display device 6, and reference numeral 8 denotes a mode for automatically selecting a magnification. A magnification automatic setting key 9 is a zoom key for setting the copy magnification in increments of 1%.
Reference numerals 11 and 11 denote fixed magnification keys for reading and selecting a fixed magnification, and reference numeral 12 denotes an equal-magnification key for returning the copying magnification to a standard magnification (actual magnification).

Reference numeral 13 denotes a density switching key for switching the copy density adjustment from automatic to manual or to the photo mode, 14 denotes a density adjustment key for finely setting the density level in the manual mode or the photo mode, and 15 denotes a copy. A tray selection key for selecting a desired paper size from paper sizes set in a paper feeding unit of the apparatus.

Reference numeral 16 denotes a copy number setting key for setting the number of copies, 17 a clear key operated when clearing the number of copies or stopping continuous copying in the middle, 18 a start key for instructing the start of copying, Reference numeral 19 denotes an all release key for releasing all of the currently set modes and returning to the normal state, reference numeral 20 denotes an interrupt key operated when a copy of another document is desired during continuous copying, and reference numeral 21 denotes a copy machine. An operation guide key for displaying a message about the operation method of the copier by operating it when you do not understand the operation,
Reference numeral 22 denotes a message forward key for displaying a continuation of the message displayed by operating the operation guide key 21. Reference numeral 23 denotes a double-sided mode setting key for setting a double-sided copying mode, and reference numeral 24 denotes a post-processing mode setting key for setting an operation mode of a post-processing device for sorting copies ejected from a copying machine.

Reference numerals 25 to 27 denote setting keys for a printer mode and a facsimile mode. 25 is a memory transmission mode key for temporarily storing a transmission original in a memory and then transmitting the same. 26 is a mode for copying and faxing a digital copying machine. A copy / fax / printer mode switching key 27 for switching between the telephone numbers is a one-touch dial key for storing a destination telephone number in advance and transmitting a telephone call to the destination by one-touch operation during transmission.

The operation panel presented this time and the various keys arranged on the operation panel are just one embodiment, and the keys provided on the operation panel differ depending on various functions mounted on the color digital copying machine. Needless to say.

(Description of Registration Correction Control Unit) FIG. 6
FIG. 2 is a cross-sectional view of a transfer and conveyance unit including a transfer and conveyance belt 216, which is a belt-shaped image forming medium having the configuration of the present invention, and a pattern image detection unit.

On the side opposite to the image recording portion side of the transfer / conveying belt 216 supported by the driving roller 214 and the driven roller 215, the back contact members 231 (231a, 231)
b), a pattern image detection sensor 232, and a pattern image detection unit 240 including a support frame 233 that supports the components while maintaining the positional relationship between these components in a fixed state.

Then, the pattern image detecting unit 2
The spring 233 (233a, 233a, 233a) is provided with a predetermined level of tension downward.
b) is provided.

Further, the support frame 232 has
34 (234a, 234b) are provided, and the driving roller 214, which is a component of the transfer / conveyance unit 213,
Frame 213a supporting driven roller 215 and the like
Guide pins 213b, 2 provided to protrude from
13c, and the pattern image detection unit 24
0 has a structure that can be displaced downward.

A spring 23 for applying a predetermined appropriate tension to the pattern image detecting unit 240 is provided.
3 (233a, 233b) are provided on both sides of the unit 240 under the same conditions, and the slots 234a, 234b
The transfer conveyance belt 216 is pressed down by the two back-surface pressing members 231a and 231b while maintaining the parallel state along.

As a result, a predetermined appropriate tension is always applied to the transfer / conveying belt 216 with which the back contact member 231 is in contact, so that the transfer / conveyance of the linear portion facing the image forming portion side on which images of each color are formed. The belt 216 enables stable running without bending, and the belt 216
A flat (flat) stable region for detecting the pattern image formed thereon is reliably formed.

Then, the pattern image detecting sensor 232, which is arranged in a predetermined positional relationship opposite to this flat (flat) stable area, is transferred to the transfer / conveying belt 216.
The pattern image formed above is detected.

Next, the position at which the pattern image formed on the transfer / conveying belt 216 is detected by the pattern image detection sensor 232 will be described.

First, the drive roller 214 for running the transfer / transport belt 216 also causes an eccentric motion due to rotation, and appears as a predetermined periodic drive unevenness of the transfer / transport belt 216.

Therefore, in order to always detect a pattern image at a fixed point (range) in the predetermined periodic drive unevenness, a point at which the pattern image is formed on the transfer / transport belt 216 is determined as follows. The distance L to the point where the pattern image formed on the belt 216 is detected is
As shown in FIG. 6, the setting is made to be an integral multiple of the circumference l of the driving roller 214.

(Description of Formation and Detection of Registration Correction Pattern Image) A method of forming a registration correction pattern image of an image forming unit for each color formed on the transfer / conveying belt 216 having the above configuration ( A method of forming a pattern image, a method of detecting a formed pattern image, and a method of correcting a resist based on a detection result will be described.

(First Embodiment) As shown in FIG. 7, the pattern image for adjusting the image writing timing formed on the transfer and conveyance belt 216 is the same in the main scanning direction by the reference image forming unit. The two pattern images formed at the timing, and the first color pattern image (B) on both ends (216a, 216b) of the transfer conveyance belt 216.
k) and a second color pattern image group (Y1, Y2, Y3).

The first color pattern image (Bk) formed here is a pattern image formed at a predetermined timing by the reference image forming unit among the image forming units of each color, and the second color pattern image (Bk). Pattern image group (Y1, Y2, Y3)
Are pattern images formed at intervals by an image forming unit which attempts to adjust a writing position with respect to a reference image forming unit among image forming units of respective colors.

The pattern image (Bk) of the first color is
The second color pattern image group (Y1, Y2, Y3) is formed at a predetermined reference timing.
Are formed at different timings, each of which is shifted by a predetermined level from the predetermined timing serving as the reference.

Then, two pattern images formed at the same timing in the main scanning direction by the reference image forming unit and the transfer / transport belt 2 at each timing.
Pattern image groups (Bk and Y1, Y2, Y3) formed on both ends 216a, 216b of the sixteen are detected by two detection sensors 232a, 232b for each pattern image.

Note that the detection sensors 232a, 232b
The change of the detection signal obtained from the detection signal is detected by the determination control circuit 440 to which the output from each detection sensor is input, and the timing of starting to write the image information of each color in the image forming unit of each color from the detection signal obtained here Is determined.

In the determination control circuit 440, a description will be given of a processing method for determining the start timing of writing the image information of each color in the image forming unit of each color. First, the image forming unit serving as a reference forms the image information at the same timing in the main scanning direction. The detection sensors 232a and 232b detect the two pattern images (Bk and Bk).

Then, the two detection sensors 232a,
The amount of deviation of the detection signal output from 232b is determined and stored and managed as correction data due to the deviation of the mounting position of the detection sensors 232a and 232b on the main scanning line.

Next, the timing at which the detection sensor 232a detects the pattern image (Bk) formed by the reference image forming unit (black Bk image recording unit),
32b is a pattern image (Y1, Y2, Y) formed by an image forming unit (yellow Y image recording unit) for adjustment.
A pattern image whose timing coincides with the detection timing of 3) is determined.

At this time, the detection sensors 232a, 232b
Needless to say, there is a shift in the detection timing due to the shift of the mounting position, and the image writing timing is adjusted in consideration of the correction data determined earlier.

In the judgment control circuit 440, there is provided a counter k for managing the number of pattern images formed in the image forming unit to be adjusted.

In the pattern image formed by the image forming unit to be adjusted, the timing of the pattern image formed by the image forming unit (yellow Y image recording unit) to be adjusted is determined by the counter. By making a determination using information such as k, the timing is set as the image writing start timing of the yellow Y image recording unit.

When the image writing start timing of the yellow Y image recording section is determined by this method, the image writing start timing of the magenta M image recording section and the cyan C image recording section is successively adjusted by the same method, and all adjustments are made. Is completed.

(Second Embodiment) As shown in FIG. 8, the pattern image for adjusting the image writing timing formed on the transfer / conveying belt 216 is the same in the main scanning direction by the reference image forming unit. Two pattern images formed at the timing and a first color pattern image group and a second color pattern image group are formed on the ends (216a, 216b) of the transfer / conveyance belt 216.

The first color pattern image group (Bk, Bk, Bk) formed here is a pattern image formed at intervals by the reference image forming unit among the image forming units of each color. The pattern images (Y1, Y2, Y3) of the second color, which are images, are respectively formed by the image forming units that are to adjust the writing position with respect to the reference image forming unit among the image forming units of each color. Are pattern images formed at intervals.

The first color pattern image group (Bk, Bk
k, Bk) are formed at predetermined timings, each of which is a reference at a predetermined interval, and the pattern image group (Y1, Y2, Y3) of the second color is a reference image having the predetermined reference. Are formed at different timings which are shifted from each other by a predetermined level.

At each timing, a group of pattern images (Bk, Bk, Bk, and Y) formed on both ends 216a and 216b of the transfer / conveyance belt 216 is obtained.
1, Y2, Y3) are detected by two detection sensors 232a, 232b for each pattern image group.

The detection sensors 232a, 232b
The change of the detection signal obtained from the detection signal is detected by the determination control circuit 440 to which the output from each detection sensor is input, and the timing of starting to write the image information of each color in the image forming unit of each color from the detection signal obtained here Is determined.

A description will be given of a processing method for determining the start timing of writing image information of each color in the image forming section of each color in the determination control circuit 440.
The detection sensors 232a and 232b detect two pattern images (Bk, Bk) formed at the same timing in the main scanning direction by the reference image forming unit.

Then, the two detection sensors 232a,
The amount of deviation of the detection signal output from 232b is determined and stored and managed as correction data due to the deviation of the mounting position of the detection sensors 232a and 232b on the main scanning line.

Next, the timing at which the detection sensor 232a detects the pattern image formed by the reference image forming unit (black Bk image recording unit) and the image forming unit (yellow Y image recording The combination of the pattern images whose timing coincides with the timing at which the pattern image formed by the section (1) is detected is determined.

At this time, the detection sensors 232a, 232b
Needless to say, there is a shift in the detection timing due to the shift of the mounting position, and the image writing timing is adjusted in consideration of the correction data determined earlier.

Note that a counter k is provided in the determination control circuit 440 to manage which group of the pattern image is being detected.

In the image forming unit (yellow Y image recording unit) that performs adjustment in the pattern images of this combination, the pattern image formed at any timing is determined by using information such as the counter k and the like. By making the determination, the timing is set as the image writing start timing of the yellow Y image recording unit.

When the image writing start timing of the yellow Y image recording section is determined by this method, the image writing start timing of the magenta M image recording section and the cyan C image recording section is successively adjusted by the same method, and all adjustments are made. Is completed.

As described above, in order to adjust the image writing timing in each image forming section, a plurality of pattern image groups formed on the transfer / conveyance belt 216 are divided into two groups by the two pattern image detection sensors 232a and 232b. A first pattern image (Bk, Bk) for correcting a shift in detection timing caused by a mounting position shift on a scanning line, and a reference image for determining an image writing timing in each image forming unit. A second pattern image (Bk, Y, M, C) formed by the forming unit and the image forming unit to be adjusted,
In consideration of the detection timing shift correction data obtained by detecting the first pattern image, a set of pattern images having a predetermined relationship in the second pattern image group is checked in the second pattern image group. That is, the write timing is determined.

In this configuration, a device for improving the accuracy of detecting a pattern image by the pattern image detection sensors 232a and 232b will be described.

The transfer / transport belt 216 is a flat belt made of a conductive material in consideration of the transfer of potential (electrons) due to transfer voltage or transfer current from the back of the transfer / transport belt 216. In general, a black belt body is used because it contains a conductive material such as carbon.

The surface of the flat belt body is also subjected to a surface treatment (a state close to a mirror surface) so that stable transfer efficiency can be obtained over the entire surface.

Therefore, if the color components of the color material forming the pattern image formed on the transfer / transport belt 216 are the same as the color components of the transfer / transport belt 216, or if the reflectance from the surface is similar, Whether the light is reflected light from the surface of the transfer conveyance belt 216, or a pattern image
C) It is difficult to see the difference between the reflected light from the surface and the pattern image detection sensors 232a and 232
The deviation of the detection timing on the main scanning line 2b cannot be accurately corrected.

Therefore, in FIGS. 7 and 8, the first pattern image is illustrated and described so as to be adjusted using an image forming unit for forming a black (Bk) image. However, as another embodiment, The reflectance from the surface of the transfer conveyance belt 216 is different,
A pattern image may be formed by using an image forming section of a color component whose difference is clearly visible as a reference image forming section.

Also, as in the case of the first pattern image,
When each of the second pattern images is formed, the reflectance from the surface of the transfer / conveying belt 216 is different, and the pattern image is formed using the image forming unit of the color component as a reference, which clearly shows the difference. May be configured.

The first and second embodiments are characterized in that two detection sensors for detecting a plurality of pattern images formed at both ends on the transfer / conveying belt have a predetermined positional relationship on the main scanning line. In order to be able to detect the set of pattern images at the same timing, the correction process for correcting the positional relationship between the two detection sensors is automatically performed in the apparatus before the adjustment process based on the pattern image detection. The point is that the image writing timing in each image forming unit can be adjusted.

(Third Embodiment) As shown in FIG. 9, a pattern image group of the first color and a pattern image group of the second color are formed on one end 216a of the transfer / transport belt 216 so as to overlap each other. Is done.

The first color pattern image group (Bk, Bk, Bk) formed here is a pattern image formed at intervals by the reference image forming unit among the image forming units of each color. The pattern images (Y1, Y2, Y3) of the second color, which are images, are respectively formed by the image forming units that are to adjust the writing position with respect to the reference image forming unit among the image forming units of each color. Are pattern images formed at intervals.

The first color pattern image group (Bk, Bk
k, Bk) are formed at predetermined timings, each of which is a reference at a predetermined interval, and the pattern image group (Y1, Y2, Y3) of the second color is a reference image having the predetermined reference. Are formed at different timings which are shifted from each other by a predetermined level.

Then, at each timing, the pattern image group (Bk, Bk, Bk, and Y1, Y) formed on one end 216a of the transfer / conveying belt 216.
2, Y3) is detected by the detection sensor 232.

The change of the detection signal obtained from the detection sensor 232 is detected by the judgment control circuit 440 to which the output from each detection sensor is input, and the image forming section of each color is obtained from the detection signal obtained here. , The start timing of writing the image information of each color is determined.

A description will be given of a processing method in the determination control circuit 440 for determining the start timing of writing the image information of each color in the image forming section of each color.
When the detection sensor 232 detects the pattern image (Bk, B
k, Bk) and the second color pattern image (Y1, Y2, Y
3) detects the transit time of each pattern image formed in an overlapping state, and determines the combination of the pattern images with the shortest detected transit time (that is, the transit time is short, The pattern images formed respectively by the reference image forming unit and the image forming unit to be adjusted are most matched.

The determination control circuit 440 is provided with a counter k for managing which group of the pattern image is being detected.

In the pattern image of this combination, in the image forming unit (yellow Y image recording unit) for performing the adjustment, it is determined whether the pattern image formed at any timing has the shortest detection passage time by the counter k.
The timing is set as the image writing start timing of the yellow Y image recording unit by making a determination using information such as the above.

When the image writing start timing of the yellow Y image recording section is determined by this method, the image writing start timing of the magenta M image recording section and the cyan C image recording section is successively adjusted by the same method, and all adjustments are made. Is completed.

A method of forming a pattern image for adjusting the start timing of writing image information in the image forming section of each color by forming the pattern image and detecting the pattern image, and a procedure of controlling the timing by detecting the pattern image are described below. Several methods are described.

The feature of this embodiment is that, among a plurality of pattern images formed at one end on the transfer / conveying belt, an image in which the pattern images overlap in an ideal state is detected. Thus, the image writing timing in each image forming unit is adjusted.

(Fourth Embodiment) As shown in FIGS. 7, 8, and 9, the pattern image formed by the reference image forming unit is different from the pattern image formed by the image forming unit to be adjusted at different timings. Are formed in plural sets.

For example, suppose that a predetermined shift amount is α for three colors of Y, M, and C, and five reference patterns of each color are formed, and the center position of the reference pattern of each color (Y, M, C) is left as it is. If represented by M and C, the formation position of each reference pattern is Y + 2α, Y + α, Y + 0, Y
-Α, Y-2α, M + 2α, M + α, M + 0, M-α,
M-2α, C + 2α, C + α, C + 0, C-α, C-2
α (hereinafter referred to as Y + 2 Y + 1 Y0 Y−1
Y-2 M + 2 M + 1 M0 M-1 M-2 C +
2 C + 1 C0 C-1 C-2).

In the embodiment, control is performed such that an adjustment pattern is formed in a color separation image forming section to be adjusted while changing the writing timing in a range of five steps.

The five-step range for changing the writing timing is a range in which the apparatus can change the writing timing of the image. If the adjustment is made within this range, the color-separated image formed in the reference image forming section is formed. The range is set within an adjustable range that can be superimposed with the above. For example, various ranges such as three steps and seven steps can be appropriately set in consideration of the required specifications of the apparatus, manufacturing costs, and the like. .

(Fifth Embodiment) With respect to the pattern image formed by the reference image forming unit, two pattern images at different timings are respectively formed on the transfer conveyance belt 216 by the image forming unit to be adjusted. A plurality of sets are formed (Y + 2 Y + 2 Y + 1 Y + 1 Y0 Y
0 Y-1 Y-1 Y-2 Y-2 M + 2 M + 2
M + 1 M + 1 M0 M0 M-1 M-1 M-2
M-2 C + 2 C + 2 C + 1 C + 1 C0 C
0 C-1 C-1 C-2 C-2).

This state is shown in FIGS. 10 and 11 (in FIGS. 10 and 11, 2 × 3 reference patterns are created for each color). As described above, the transfer and conveyance belt 2
When forming a pattern image at a plurality of different image writing timings formed on the plurality of pattern images 16, a plurality of pattern images at the same writing timing are formed, and the formed pattern image at the same writing timing is detected. If the detection result is determined based on the average (statistics) of the detection results obtained by the image detection, the detection accuracy is improved.

(Sixth Embodiment) As shown in FIG.
A plurality of adjustments formed by combining a pattern image sequentially formed at a different timing in the image forming unit to be adjusted and a pattern image sequentially formed at a predetermined timing in the reference image forming unit The adjustment is repeated until a pattern image in which each pattern image has a predetermined positional relationship among the pattern images for use is detected.

For example, by checking the overlapping state of the respective pattern images, when a pattern image (Y, M, C) having a predetermined width is detected by passing through the pattern image detecting sensor 232, The image writing timing in the image forming unit to be adjusted is determined, and the subsequent pattern image formation is stopped.

When the adjustment of the writing timing of the first color with respect to the reference color is completed, the process proceeds to the adjustment of the writing timing of the second color (Y + 2 Y + 1 Y0 Y−
1Y-2 Y-3 Y-4 Y-5 OK M + 2 M
+1 M0 M-1 OKC + 2 C + 1 OK, where OK indicates that the timing adjustment has been completed for each color).

(Seventh Embodiment) In the above embodiment, the pattern images (Y, M, C) having a predetermined positional relationship
Is detected, the next level of timing pattern adjustment is performed, and the overlapping state of the formed pattern images is checked. If no further adjustment is necessary, the process proceeds to the next color timing adjustment step. In this case, more accurate adjustment can be performed.

That is, as shown in FIG. 13, even if a pattern image (Y, M, C) having a predetermined width is detected, a further pattern image (Y + 1, M +
(1, C + 1), if the detection width is wider than the pattern image (Y, M, C) having a predetermined width, the timing formed earlier is finally determined (Y
+2 Y + 1 Y0 Y-1 Y-2 OK Y-3
OK M + 2 M + 1 M0 M-1 OK M-2
OK C + 2 C + 1 OK C0 OK).

[0160]

According to the first aspect of the present invention, the pattern image formed by the reference image forming unit and the image forming unit to be adjusted are formed on the main scanning line of the transfer / conveying belt. The formed pattern images are formed as a set, and the pattern image formed by the reference image forming unit and the pattern image formed by the image forming unit to be adjusted in this set are positioned at predetermined positions. Since the image writing timing in the image forming unit to be detected and adjusted in relation to the image forming unit is determined, the transfer conveyance belt stretched between the driving roller and the driven roller may be removed from various factors included in the driving mechanism. The pattern formed by the reference image forming unit without being affected by the generated periodic drive conveyance unevenness, etc. Image, pattern image formed by the image forming unit to be adjusted becomes possible to detect the same conditions, the information obtained from the sensor is most appropriate.

Therefore, the images for each color separation image formed in each image forming section are accurately overlapped on the transfer / conveying belt, and it is possible to faithfully reproduce the image expression of the color image.

According to the invention described in claim 2,
A first method for correcting a displacement between two pattern detection sensors
The pattern and the second pattern for adjusting the image writing timing in the image forming unit are detected by the two sensors, and the image forming timing in each image forming unit is adjusted. As a result, the image writing start timing in each image forming unit is determined, and the color separation image of each color formed in each image forming unit can be reliably overlapped on the transfer unit, and the image expression of the color image is faithfully reproduced. can do.

According to the third aspect of the present invention,
The first pattern image for correcting the detection timing deviation of the two pattern image detection sensors with respect to the main scanning line is a developer having a difference of at least a predetermined value from the light reflection characteristic of the transfer unit surface in each image forming unit. Since the image is formed by an image forming unit capable of forming a pattern image in advance, even if the pattern image formed on the transfer belt is detected using a relatively inexpensive sensor such as a reflection type sensor, the transfer belt The difference in the detection timing of the two sensors can be reliably corrected by the difference in the reflectance from the surface and the pattern image surface.

Therefore, it is possible to accurately set the image writing timing in each image forming section, and it is possible to reliably overlap the color separation images of each color formed in each image forming section on the transfer means. Thus, the image expression of the color image can be faithfully reproduced.

According to the invention described in claim 4,
Among the second pattern images formed for adjusting the image writing timing in each image forming unit, the reference pattern image formed by the reference image forming unit is
In each image forming unit, the pattern image formed on the transfer belt is formed by the image forming unit capable of forming a pattern image with a developer having a difference of at least a predetermined value from the light reflection characteristic of the transfer unit surface. Even if a relatively cheap sensor such as a reflection sensor is used to detect the pattern image, the reference pattern image is surely detected by the detection sensor based on the difference in reflectance from the transfer belt surface and the pattern image surface. The image writing timing can be adjusted based on the detection signal from the detection sensor.

Therefore, it is possible to accurately set the image writing timing in each image forming section, and it is possible to reliably overlap the color separation images of each color formed in each image forming section on the transfer means. The image expression of the color image can be faithfully reproduced.

According to the invention described in claim 5,
Since the shift amounts of the two sensors confirmed by the first pattern image detection are managed as correction data, and the sensor output results at the time of the second pattern detection are corrected, the image writing start timing in each image forming unit is detected. At this stage, the image writing start timing in each image forming unit can be reliably corrected.

According to the invention described in claim 6,
After detecting the first pattern image in order to correct the sensor position shift, a second pattern image for adjusting the write timing in each image forming unit is detected, and then the detected data is corrected by the correction data to determine the write timing. Therefore, when the image writing timing is detected for each image forming unit, the timing is corrected based on the mounting position deviation of the sensor, so that the image writing start timing in each image forming unit is surely adjusted. Can be.

According to the invention described in claim 7,
After detecting the second pattern image for adjusting the writing timing in each image forming unit, detecting the first pattern image to correct the sensor position shift, and then correcting the detected data, When the image writing timing is detected, the image writing timing in each image forming unit is corrected at once based on the displacement of the mounting position of the sensor, so that the process is simple and the image writing in each image forming unit is surely performed. The start timing can be adjusted.

According to the invention described in claim 8,
A first pattern image formed by a reference image forming unit having the same positional relationship on the main scanning line,
One pattern image formed by the reference image forming unit having substantially the same positional relationship with respect to the main scanning direction, and a plurality of pattern images formed by the image forming unit to be adjusted, each having a different forming timing. Is formed, so that it is not affected by driving unevenness of the transfer unit and the like, and the position of each of the two sensors for detecting the pattern image is taken into account in consideration of the displacement of the mounting position. The image writing start timing can be adjusted.

Further, the color separation images formed by the respective image forming sections can be reliably superimposed on the transfer means, and the image expression of the color image can be faithfully reproduced.

According to the ninth aspect of the present invention,
A first pattern image formed by a reference image forming unit having the same positional relationship on the main scanning line,
One of the pattern images formed at a predetermined timing by the reference image forming means having substantially the same positional relationship with respect to the main scanning direction, and each of the pattern images formed by the image forming means to be adjusted has a forming timing. A plurality of second pattern images are formed by combining one of a plurality of different pattern images, so that two sensors that detect the pattern images can be used without being affected by driving unevenness such as a transfer unit. The image writing start timing in each image forming unit can be adjusted in consideration of the mounting position shift.

Further, the color separation images formed by the respective image forming sections can be surely superimposed on the transfer means, and the image expression of the color image can be faithfully reproduced.

According to the tenth aspect, based on the correction data obtained by detecting the first pattern image, detection is performed by the two detection sensors at the same timing in the main scanning direction. The image forming start timing in each image forming unit is adjusted by checking the pattern image forming timing, so that each sensor attached to two different positions,
Even if the pattern image for adjusting the writing timing is detected, the timing can be corrected in consideration of the shift of the detection timing due to the shift of the mounting position of the two sensors. Color separation images can be reliably superimposed on the transfer means, and the image expression of the color image can be faithfully reproduced.

According to the eleventh aspect of the present invention, the number of pattern images formed at different timings is controlled from the detection signal of the second pattern image detection sensor. And a pattern image formed by a reference image forming unit with a simple configuration such as only a counter, and an image forming unit to be adjusted, a timing at which the output of this sensor matches is detected, and its equivalent is detected. Since it is possible to easily determine at which timing the pattern image serving as the detection timing is formed, the circuit configuration can be simplified, and the cost can be reduced.

According to the twelfth aspect of the present invention, the number of pattern images formed as a plurality of sets is detected from the detection signal of the first or second pattern image detection sensor. Detects a pattern image formed by a reference image forming unit and an image forming unit to be adjusted with a simple configuration including only two sensors and a counter, and detects a timing when outputs of the sensors match. The circuit configuration is simple because it is possible to easily determine at which timing a pattern image having the same detection timing is formed.

According to the thirteenth aspect of the present invention, a plurality of reference color pattern images and one of the adjustment color pattern images each having different timing are formed so as to partially overlap each other. Since the writing timing is controlled by detecting the pattern image closest to the predetermined positional relationship among the pattern images, on the transfer conveyance belt,
The reference image forming unit and the image forming unit to be adjusted form a pattern image so as to overlap each other at a position under the same image forming condition, so that the reference image is not affected by driving unevenness or the like. It is possible to accurately adjust the image writing start timing of the image forming unit to be adjusted with the image forming unit.

Therefore, the images of the respective colors formed by the image forming units of the respective colors are placed on the transfer belt and superposed with high positional accuracy, and the color images can be faithfully reproduced.

According to the fourteenth aspect of the present invention, the pattern images are sequentially formed at the predetermined positions of the transfer belt, and each of the pattern images is sequentially detected by one sensor. The circuit configuration is simple because it is only necessary to detect the pattern image formed by the reference image forming unit and the image forming unit to be adjusted in the configuration and determine the timing at which the output of this sensor matches. And cost can be reduced.

According to the fifteenth aspect, since the number of pattern images formed at different timings is detected from the detection signal of the pattern image detection sensor, it is managed. The pattern image formed by the reference image forming unit and the image forming unit to be adjusted is detected with a simple configuration such as a simple configuration, and the timing at which the output of this sensor matches is detected, and the equivalent detection timing is detected. Since it is possible to easily determine at what timing the pattern image to be formed is formed, the circuit configuration is simplified and the cost can be reduced.

According to the sixteenth aspect of the present invention, one of the reference color component pattern image and the second color component pattern image, each having a different forming timing, is provided in the sub-scanning direction. Since the formation width is the same, there is no problem that one pattern image is completely covered by the other pattern image (it does not include a state where the two pattern images are perfectly matched) and one pattern image is not accurately detected. By simply managing the output at all times, accurate registration adjustment can be easily performed.

According to the seventeenth aspect, the width of the pattern image is detected and the writing timing is controlled from the timing at which the minimum width pattern image is formed. The registration adjustment can be performed by detecting a pattern image at an appropriate timing.

According to the eighteenth aspect, a plurality of sets of pattern images are formed at different timings for each color (for example, YMC), and an appropriate timing pattern is detected for each color to set the write timing. Since control is performed, registration adjustment can be automatically completed for a plurality of image forming units in a short time.

According to the nineteenth aspect of the invention, when pattern images having different timings are formed, a plurality of pattern images having the same timing are formed, and a plurality of pattern images having the same timing are formed. Is detected and the detection result is determined based on the calculation of the average (statistics) of the detection result, etc., so that the accuracy of the registration adjustment can be improved.

According to the twentieth aspect, the adjustment is repeated until a pattern image having a predetermined positional relationship between the respective pattern images is detected from the plurality of sets of the formed pattern images. It is possible to reliably perform registration adjustment for each image forming unit of each color.

According to the twenty-first aspect, when the writing timing adjustment of the first color with respect to the reference color is completed, the process shifts to the writing timing adjustment of the second color. In addition to the registration adjustment, each image forming unit can be automatically adjusted.

According to the twenty-second aspect of the present invention, even if a pattern image having a predetermined positional relationship is detected, the next level of timing pattern adjustment is performed. In this case, the most suitable level of the resist adjustment can be compensated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the overall structure of a color digital copying machine provided with the present invention.

FIG. 2 is a configuration diagram of a network system having a color digital copying machine as a core.

FIG. 3 is a block diagram illustrating a circuit configuration of an image processing unit of the color digital copying machine.

FIG. 4 is an overall control block diagram of the color digital copying machine.

FIG. 5 is a plan view showing an example of an operation panel portion in the color digital copying machine.

FIG. 6 is a transfer conveyance belt that is a belt-shaped image forming medium,
FIG. 4 is an apparatus cross-sectional view of a transfer and transport unit including a pattern image detection unit and the like.

FIG. 7 is a diagram illustrating a method of forming a pattern image and a method of detecting the pattern image according to an embodiment.

FIG. 8 is a diagram illustrating a method of forming a pattern image and a method of detecting a pattern image according to an embodiment.

FIG. 9 is a diagram illustrating a method of forming a pattern image and a method of detecting a pattern image according to an embodiment.

FIG. 10 is a diagram illustrating a pattern image forming method according to an embodiment.

FIG. 11 is a diagram illustrating a pattern image forming method according to an embodiment.

FIG. 12 is a diagram illustrating a pattern image forming method according to an embodiment.

FIG. 13 is a diagram illustrating a pattern image forming method according to an embodiment.

[Description of Signs] 216 Transfer Conveying Belt 216a Both Ends 216b Both Ends 232a Detection Sensor 232b Detection Sensor 240 Pattern Image Detection Unit 440 Judgment Control Circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Shoichiro Yoshiura 22-22, Nagaike-cho, Abeno-ku, Osaka, Osaka Inside Sharp Corporation (72) Hideo Matsuda 22-22, Nagaike-cho, Abeno-ku, Osaka, Osaka Sharp Inside the corporation

Claims (22)

[Claims] 1. An image information input unit for inputting color image information for each color component, a plurality of image forming units for forming an image for each input color image information, and the plurality of image forming units Transfer means for transferring each of the images formed in the above, a pattern image forming means for forming a pattern image for alignment of each image on the transfer means, and a pattern for detecting the pattern image Image detection means;
An image forming apparatus comprising: an adjusting unit configured to adjust a timing of superimposing each color image formed by the plurality of image forming units on a transfer unit based on a detection timing of the pattern image by the pattern image detecting unit. The pattern image detecting means is provided at substantially both ends of the transfer means,
A pattern image repeatedly formed at a predetermined timing by the reference image forming unit and a pattern image formed at a different timing by the image forming unit to be adjusted are formed, and substantially both ends of the transfer unit are formed. And a first and a second detecting means for outputting a detection signal when the pattern image is detected by the image forming unit, wherein the adjusting means comprises a pattern which is repeatedly formed at a predetermined timing by a reference image forming unit. Images and
An image forming apparatus, wherein the pattern images formed at different timings by the image forming unit to be adjusted are adjusted to be substantially opposed positions on a line in the main scanning direction of the transfer unit. 2. An image information input unit for inputting color image information for each color component, a plurality of image forming units for forming an image for each input color image information, and the plurality of image forming units Transfer means for transferring each of the images formed in the above, a pattern image forming means for forming a pattern image for alignment of each image on the transfer means, and a pattern for detecting the pattern image Image detection means;
An image forming apparatus comprising: an adjusting unit configured to adjust a timing of superimposing each color image formed by the plurality of image forming units on a transfer unit based on a detection timing of the pattern image by the pattern image detecting unit. The pattern image detecting means is provided at substantially both ends of the transfer means,
A pattern image repeatedly formed at a predetermined timing by the reference image forming unit and a pattern image formed at a different timing by the image forming unit to be adjusted are formed, and substantially both ends of the transfer unit are formed. And a first and a second detecting means for outputting a detection signal when the pattern image is detected by the section, and for correcting a shift in detection timing of the first and the second detecting means with respect to the main scanning line. A first output unit for outputting the first pattern image, and a second output unit for outputting a second pattern image for adjusting the distance between the image forming units in the image forming unit for each color component. And an output unit. 3. The image forming apparatus according to claim 2, wherein the first pattern image is formed of a developer having a light reflection characteristic different from the light reflection characteristic of the surface of the transfer means in each image forming section. Image forming apparatus. 4. The image forming apparatus according to claim 2, wherein the second pattern image is formed of a developer having a light reflection characteristic different from the light reflection characteristic of the surface of the transfer means in each image forming section. Image forming apparatus. 5. A means for obtaining, as correction data, a shift amount of a detection timing with respect to a main scanning line in each detection means from a detection signal obtained when a first pattern image is detected by the first and second detection means. 3. The image forming apparatus according to claim 2, wherein when the second pattern image is detected by the detection unit and the image writing start timing in each image forming unit is adjusted, the image writing start timing is determined based on the correction data. Image forming apparatus. 6. A pattern image forming means for outputting a first pattern image for correcting a detection timing shift of the first and second image detecting means with respect to a main scanning line, and thereafter outputting the image forming means for each color component. And outputting a second pattern image for adjusting the distance between the image forming units in the step (a), and when an image writing timing is detected for each image forming unit, the timing based on the amount of displacement of the mounting position of the detecting unit. The image forming apparatus according to claim 2, wherein the correction is performed. 7. A pattern image forming unit, after outputting a second pattern image, outputs a first pattern image for correcting a detection timing shift of the first and second image detecting units with respect to a main scanning line. After the image writing timing in each image forming unit is detected,
3. The image forming apparatus according to claim 2, wherein the timing is corrected in consideration of a mounting position shift of the detection unit. 8. A first pattern image is formed by a reference image forming means, and has substantially the same positional relationship with respect to the main scanning direction at substantially both ends on the transfer means. And a plurality of pattern images each formed by the image forming unit to be adjusted, each of which has a different forming timing. 3. The image forming apparatus according to claim 2, wherein the both ends have substantially the same positional relationship with respect to the main scanning direction. 9. The first pattern image is formed by a reference image forming means, and has substantially the same positional relationship in the main scanning direction at substantially both ends on the transfer means. One of the pattern images formed at a predetermined timing by the image forming means, and one of a plurality of pattern images formed by the image forming means to be adjusted, each having a different forming timing. 3. The image forming apparatus according to claim 2, wherein the image forming apparatus is a set of pattern images, and has substantially the same positional relationship with respect to the main scanning direction at substantially both ends on the transfer unit. 10. The image writing timing adjusting means,
Based on the correction data obtained by detecting the first pattern image, the pattern image detecting means confirms the formation timing of the pattern images detected at the same timing in the main scanning direction by the two detection sensors, and forms each image. The image forming apparatus according to claim 8, wherein an image writing start timing in the unit is adjusted. 11. A pattern image detection management means for managing the number of pattern images detected at different timings based on a pattern image detection signal from a second detection means. The image forming apparatus according to claim 8, wherein: 12. A pattern image for managing the number of a plurality of sets of pattern images formed at different timings based on a pattern image detection signal from the first or second detection means. The image forming apparatus according to claim 9, further comprising a detection management unit. 13. An image information input unit for inputting color image information for each color component, a plurality of image forming units for forming an image for each input color image information, and the plurality of image forming units Transfer means for transferring each of the images formed in the above, a pattern image forming means for forming a pattern image for alignment of each image on the transfer means, and a pattern for detecting the pattern image Image detection means;
An image forming apparatus comprising: a control unit configured to control a timing of superimposing each color image formed by the plurality of image forming units on a transfer unit based on a detection timing of the pattern image by the pattern image detecting unit. The pattern image forming means forms a plurality of detection pattern images in which a first color pattern image serving as a reference and one of the second color pattern images having different formation timings are overlapped, and the first color pattern image is formed. And detecting a set of pattern images in which the positional relationship between the second color pattern image and the second color pattern image is in a predetermined positional relationship, and controlling the image writing timing in the image forming unit in accordance with the detected set of pattern image information. Characteristic image forming apparatus. 14. A plurality of sets of detection pattern images are formed on the transfer means along the moving direction of the transfer means, and the detection pattern images are formed at predetermined positions to detect the detection pattern images formed on the transfer means. 14. The image forming apparatus according to claim 13, wherein the image detecting means is disposed to face the image forming apparatus. 15. A pattern image detection management means for managing which of a plurality of pattern images formed on a transfer means is detected based on a pattern image detection signal from the pattern image detection means. The image forming apparatus according to claim 14, wherein: 16. A pattern image of a first color serving as a reference formed by a pattern image forming means and one of pattern images of a second color having different formation timings have the same width in the transport direction of the transfer means. The image forming apparatus according to claim 13, wherein the image forming apparatus has a width. 17. A pattern image detecting means for detecting a width of a plurality of sets of detected pattern images, and an image writing timing of an image forming unit based on a width of the detected pattern image detected by the detecting means being the smallest. 17. The image forming apparatus according to claim 16, wherein: 18. A pattern image forming unit which is formed by a reference image forming unit for each image forming unit other than a reference image forming unit among image forming units for forming an image for each color component. 14. The image forming apparatus according to claim 8, wherein a plurality of pattern images at different timings are sequentially formed on the pattern image. 19. When forming pattern images at different timings, the pattern image forming means forms a plurality of pattern images having the same timing and determines a detection result based on the detection results of the plurality of pattern images. The image forming apparatus according to claim 18, wherein: 20. A pattern image forming unit which is formed by a reference image forming unit among image forming units other than a reference image forming unit among image forming units for forming an image for each color component. A plurality of pattern images each having a different timing are formed as a pair with the pattern image, and the pattern images having the different timings are detected by the pattern image detecting means so as to have a predetermined positional relationship with a reference pattern image. 14. The image forming apparatus according to claim 8, 9 or 13, wherein the image forming apparatus is formed repeatedly. 21. The pattern image forming means, when a pattern image having a predetermined positional relationship is detected by the pattern image detecting means, shifts to pattern image formation by another image forming means. The image forming apparatus as described in the above. 22. A pattern image forming means for forming at least one pattern image having a different timing and detecting a position of the pattern image as a reference even when a pattern image having a predetermined positional relationship is detected by the pattern image detecting means. The image forming apparatus according to claim 21, wherein the relationship is detected.