JP5853385B2 - Color variation detection device, image forming apparatus, color variation detection control program, and color variation detection control method - Google Patents

Description

The present invention relates to a color variation detection device, an image forming apparatus , a color variation detection control program, and a color variation detection control program , and more particularly to a color variation detection device that detects color variation over time during image formation, and the color variation. copying machine provided with a detection device, a printer, a facsimile, an image forming apparatus such as a digital MFP, related to the color variation detection control program and color variation detecting control method for executing by a computer the color change detected.

  In an image forming apparatus such as an ink jet printer, a color reproduced on a recording medium may change with time due to a change in ink state due to a temperature change or a humidity change. Therefore, color change is detected and color correction is performed. As this technique, for example, the invention described in Patent Document 1 (Japanese Patent Laid-Open No. 2002-120388) is known. In the present invention, an input device such as a scanner is used to print two types of test patterns consisting of a plurality of dark gray mixed color patches in which the mixing ratio of a plurality of chromatic color materials is changed. The characteristics of the input / output signals of the printing apparatus are estimated and corrected based on two mixed color patches selected from the types of test patterns.

  However, in the conventional color correction including the invention described in Patent Document 1, a test pattern is recorded on a recording medium, and the recorded test pattern is read to obtain correction data. Was acquired after all the recordings were completed. For this reason, it has been impossible to detect a color change or variation that occurs in an image being recorded while actually recording the image, or to monitor the color change or variation state.

  Therefore, a problem to be solved by the present invention is to make it possible to detect color variations that occur during image recording while the image is being recorded.

In order to solve the above-described problems, the present invention is a color variation detection device that detects color variation of the same color, and detects a predetermined range of the same color as a continuous color from an ink ejection signal generated from input image data. detection means for, imaging means for acquiring imaging data by taking an image the continuous color is recorded by the recording means for recording an image on a recording medium based on the ink ejection signal is detected by the pre-Symbol detection means Determination means for determining color variation by comparing actual values of the imaging data having the same position information as the continuous color data, and the detection means records the second information when recording the same information on a plurality of sheets. Is characterized in that a continuous color is detected using color information of a continuous color different from that of the first sheet .

In the embodiment described later, the color variation detection device is in the color variation detection system 200, the input image data is in the image data 102, the ink ejection signal is in the reference numeral 104, the detection unit is in the continuous color ejection detection module 201, and the recording unit. the recording head 21 to 24, the imaging means imaging unit 30, the judgment means color variance determining section 205, color information reproducibility RGB values, and the measured value to the measured RGB values,, respectively Re its corresponding.

  According to the present invention, it is possible to detect a color variation that occurs during image recording while the image is being recorded.

1 is a diagram illustrating a schematic configuration of a printing unit of a printer according to an embodiment of the present invention. It is a top view which shows the principal part of the carriage in FIG. FIG. 3 is a perspective view of a main part of the carriage shown in FIG. 2. 2 is a block diagram illustrating a hardware configuration of a printer including a color variation detection system. FIG. It is a block diagram which shows the processing structure of a color variation detection system. It is a flowchart which shows the main routine of the detection process performed with a color variation detection system. It is explanatory drawing which shows the imaging possible range with respect to a recording medium. It is explanatory drawing which shows the use range of imaging data. It is explanatory drawing including the flowchart which shows a continuous color discharge detection procedure. It is explanatory drawing which shows continuous color data and imaging data. It is explanatory drawing which shows the process sequence of continuous color data and imaging data. It is a flowchart which shows the process sequence of the judgment process of a color variation judgment part.

  The present invention is characterized in that continuous color ink ejection is determined during image recording, continuous portions are imaged immediately after ink ejection, and RGB data captured during printing are compared.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a schematic configuration of a printing unit of a printer 100 as an image forming apparatus according to an embodiment of the present invention. In the figure, the printing unit of the printer 100 is configured around a carriage 5 on which recording heads 21, 22, 23, 24 of an ink jet method (droplet discharge type) are mounted. The carriage 5 is held by a guide rod 1 and a sub guide 2 spanned between the left and right side plates 3 and 4 via a bearing and a sub guide receiving portion 11 (not shown), respectively, in the directions of arrows X1 and X2 (main scanning direction). Is slidable. The carriage 5 has recording heads 21 and 22 that discharge black (K) ink droplets, a recording head 23 that discharges yellow (Y) and magenta (M) ink droplets, and a recording that discharges cyan (C) ink droplets. A head 24 is mounted.

  A main scanning mechanism that moves and scans the carriage 5 is disposed on one side in the main scanning direction, a driving pulley 7 that is rotationally driven by the main scanning motor 8, and the other side in the main scanning direction. A driven pulley 15 and a timing belt 9 wound around the driving pulley 7 and the driven pulley 15 are provided. The driven pulley 15 is tensioned outward (in a direction away from the drive pulley 7) by a tension spring (not shown). A part of the timing belt 9 is fixedly held by a belt holding portion 10 provided on the back side of the carriage 5, whereby the carriage 5 moves in the main scanning direction as the timing belt 9 rotates.

  An encoder sheet 26 is disposed along the main scanning direction of the carriage 5, and the encoder sheet 27 can be read by an encoder sensor 27 provided on the carriage 5 to detect the main scanning position of the carriage 5. Among the main scanning areas of the carriage 5, in the recording area, a sheet-like recording medium (hereinafter simply referred to as a recording medium) is in a direction indicated by an arrow Y1 (sub-scanning direction) orthogonal to the main scanning direction of the carriage 5 by a feed mechanism (not shown). ) Intermittently.

  Further, an imaging unit 30 is attached to an end portion on the downstream side with respect to the moving direction of the carriage 5 in the main scanning direction (right side in FIG. 1), and moves together with the carriage 5 in the main scanning direction. The center of the imaging unit 30 is assembled on one straight line with the centers of the recording heads 21, 22, 23, 24 in the X-axis direction (arrow X1, X2 direction). As a result, the image immediately after being recorded on the recording medium by the recording heads 21, 22, 23, and 24 can be captured while moving in the main scanning direction. Reference numeral 14 denotes a maintenance mechanism for maintaining the ink ejection action of the recording heads 21 to 24.

  As described above, in the printer 100 according to the present embodiment, the recording heads 21 to 24 are driven according to the image information while moving the carriage 5 in the main scanning direction and intermittently feeding a recording medium (not shown) in the sub scanning direction. Then, the liquid droplets are ejected, and a full-color visible image based on the image data can be formed on the recording medium.

  2 is a plan view showing the main part of the carriage in FIG. 1, and FIG. 3 is a perspective view thereof. In these drawings, recording heads 21, 22, 23, and 24 are mounted on the carriage 5 shown in FIGS. 2 and 3, and nozzle rows 21a and 22a are provided according to image data in accordance with instructions from an image recording module 201 described later. , 23a, and 24a, each color ink is ejected and an image is recorded on a recording medium.

  The imaging unit 30 is attached to the carriage 5 and reciprocates in the main scanning direction together with the recording heads 21 to 24, and performs imaging together with image recording. The imaging unit 30 includes an image sensor 31 and captures an image recorded on a recording medium via a lens 32. The image pickup unit 30 may be attached to either the front, rear, left, or right of the carriage 5, but if it is intended to pick up an image immediately after image formation, the image pickup unit 30 is formed on the downstream surface in the main scanning direction as shown in FIGS. It is desirable to install. Further, instead of the two-dimensional image sensor 31, photodiodes that receive light through filters of each color can be used, and color misregistration can be detected by comparing colors. The image pickup unit 30 is sufficient if it is an apparatus that can pick up colors at a carriage moving speed during recording.

  Note that the position of the imaging unit 30 can be determined by the encoder value obtained by reading the encoder sheet 26 with the encoder sensor 27 as described above. Alternatively, the position of the ejection data in the main scanning direction can be obtained by counting the data rows to the nozzles of the recording heads 21 to 24 in the main scanning direction.

  FIG. 4 is a block diagram illustrating a hardware configuration of a printer including the color variation detection system. In FIG. 1, the printer 100 includes an operation unit 110, a monitor 120, a controller 130, an interface 140, an image processing unit 150, a control unit 160, a recording unit 170, and an imaging unit 180. The printer 100 and the host PC 101 are connected via the interface 140. It is connected.

  The operation unit 110 is used by a user to input an operation. The monitor 120 displays a display for input and a system status, and the user I / F is configured by both. Also, report when color variation occurs. The report destination may be the host PC 101. The controller 130 controls the entire printer and each unit, and includes control elements such as a CPU (Central Processing Unit), a ROM (Read-Only Memory), a RAM (Random Access Memory), and an EEPROM (Electrically Erasable Programmable Read-Only Memory). . The external host PC 101 and each unit in the printer 100 are connected by an interface 140. The CPU reads the program code stored in the ROM, develops it in the RAM, and executes control of each unit. Image data is sent from the host PC 101 to the image processing unit 305 via the interface 304.

  The image processing unit 150 includes a recorded image processing unit 151 and a memory 152, generates image processing data for performing image recording by the recorded image processing unit 151, and stores the generated image processing data in the memory 152.

  The control unit 160 includes a recording control unit 161, a continuous color ejection detection unit 162, an imaging control unit 163, a color variation detection unit 164, and a memory 165. The recording control unit 161 controls the recording unit 170, and from the main scanning encoder sensor 27. In accordance with the position information, the ink corresponding to the input image data is formed on the recording medium by ejecting ink from the recording heads 21 to 24. The feeding amount of the recording medium is controlled by position information from the sub scanning encoder sensor.

  The recording control unit 161 controls image recording based on the image data processed by the image processing unit 150. The continuous color ejection detection unit 162 reads the ink ejection information of the recording heads 21 to 24 handled by the recording control unit 161 and detects continuous recording regions of the same color. A continuous recording area of the same color is referred to as a continuous color here. The imaging control unit 163 controls the imaging unit 180 and images the recorded image formed on the recording medium with the image sensor 31. The color variation detection unit 164 detects color variation from the captured image data and the detected continuous color information. The imaging data is coordinates and RGB values. The memory 165 stores imaging data, and stores detected continuous color information and color variation information. The memory temporarily stores image data and can discard data that is not continuous color data.

  The recording unit 170 includes recording heads 21 to 24, a main scanning encoder sensor 27, and a sub scanning encoder sensor 28, and performs image recording on a recording medium. Image recording is performed by ejecting ink from the recording heads 21 to 24. The positional information of the recording heads 21 to 24 at that time is acquired by, for example, the main scanning encoder sensor 27 and the sub scanning encoder sensor 28 and is passed to the control unit 160.

  The imaging unit 180 includes the image sensor 31 and captures an image recorded on a recording medium.

  FIG. 5 is a block diagram showing a processing configuration of the color variation detection system. The color variation detection system 200 of the printer 100 includes a continuous color block detection module 201, a data storage module 203, a memory 165, and a color variation determination unit 204, and processes an input ink ejection signal 104 to determine color variation.

  The ink ejection signal 104 is a signal for driving the recording heads 21 to 24 to perform image recording, and is output from the image recording module 103. The image recording module 103 renders the image data 102 sent from the host PC 101 to create scan data, and outputs an ink ejection signal 104 for recording by the recording heads 21 to 24. Image data 102 is data to be formed on a recording medium.

  The image recording module 103 is operated by the recording control unit 161. When the image data 102 is input and image recording is started, the ink recording signal 104 is output to the recording heads 21 to 24.

  The imaging unit 30 operates in the imaging unit 315, and when image recording is started, the imaging data 105 obtained from the image sensor 31 is sent to the data storage module 203.

  The reporting unit 106 reports information about color variation to the outside. When the color variation is determined, information is stored in the memory 165 and reported using the monitor 120 at the end of recording. It may be reported at the same time when judging the color variation. Further, the reporting method is not limited to the display on the monitor 120. For example, the report may be reported to the host PC 101.

Hereinafter, the function of each module of the color variation detection system 200 will be described.
The continuous color ejection detection module 201 operates in the continuous color ejection detection unit 162, receives the ink ejection signal 104 from the image recording module 103 to the recording heads 21 to 24, and detects the continuous color ejection, the data storage module 203. The continuous color data 202 is sent to. Therefore, the image recording module 103 can record an image without being conscious of the color variation detection system.

  The data storage module 203 operates with the color variation detection unit 164. The continuous color data 202 and the imaging data 105 that are input are temporarily stored in the memory 165, respectively.

  The color variation determination unit 205 operates in the color variation detection unit 164 and selects the image data 105 stored in the memory 165 that corresponds to the recording position of the continuous color data 202. The actually measured RGB values are compared between portions where the same color ejection instruction is issued, and color variation during recording of one image is determined. Here, RGB values are used as an example, but any color values can be used, and LAB, CMYK, or the like can be used. Note that imaging data that does not correspond to the recording position of the continuous color data 202 is not used for color variation determination and may be discarded without being stored in the memory 165.

  FIG. 6 is a flowchart showing a main routine of detection processing executed in the color variation detection system.

  When image recording is started by a user's instruction from, for example, the host PC 101, image recording on the recording medium starts. In this image recording, there is a possibility that the color reproduced in the image always changes due to a change in the ink state due to a temperature change or a humidity change. Therefore, when image recording is started (step S101), the imaging unit 30 moves according to the carriage 5, and an image of the recording medium after ink ejection is taken (step S102). Even if there is a delay corresponding to the moving distance from the recording heads 21 to 24 to the imaging unit 30 and the operation speed at that time after the ink is ejected from the recording heads 21 to 24 and before that portion is imaged. There is no inconvenience.

  After the imaging is completed, it is determined whether there is a continuous color (step S103). If it is determined that the color is continuous, the continuous color data is stored (step S104). If it is not determined that the color is continuous, if the recording is not completed (step S108: No), the process returns to step S102 to continue imaging and record. If completed (step S108: Yes), the result of color variation detection is reported (step S109).

  On the other hand, when the continuous color data is stored in the memory 165 in step S103 (step S104), the imaging data corresponding to the continuous color position is selected from the imaging data temporarily stored in the memory 165 (step S105). . The selection of the imaging data is performed by comparing the RGB values of the imaging data, and when it is determined that there is a color variation in the recorded image based on the comparison result (step S106: Yes), the determination result is stored in the memory 165. Accumulate (step S107). After the accumulation, it is determined whether or not the recording is finished (step S108). If the recording is not finished, the processes after step S102 are repeated. If the recording is finished, the accumulation result is reported (step S109). Even if it is not determined in step S106 that the color has changed, the recording end determination in step S108 is executed.

  In addition to this, after recording, it is also possible to select a portion having the same color from the accumulated imaging data, discriminate the color variation for each color, and report the information. The color variation can be reported during the image recording even after the image recording is not completed. The timing of reporting is arbitrary.

  FIG. 7 is an explanatory diagram showing the imageable range for the recording medium. Since the range that can be captured is limited only when the image sensor 31 captures a range smaller than the width of the recording heads 21 to 24, it is necessary to set an imageable range. When causing the image sensor 31 to capture a range larger than the recording head width, it is not necessary to set this range. When an image is formed on a recording medium, the carriage 5 reciprocates in the main scanning direction, so that the recording heads 21 to 24 also move in the main scanning direction and eject ink. When the recording of one line is completed, the recording medium operates in the sub-scanning direction, and the operation of moving to the recording of the next line is repeated. In this way, in the case of a printing sequence called one-pass in which the recording medium operates in the sub-scanning direction after one line of recording is finished and moves to recording of the next line, the imaging unit 30 is as shown in FIG. Therefore, in one scan of the carriage 5, only a limited range of images on the recording medium can be acquired.

  Therefore, the row number D1 is set in order for the feeding of the recording medium in the sub-scanning direction. In the example of FIG. 7, numbers from A to U are assigned as the row number D1. Further, the range that can be ejected in one scan is the head print width D2, and the portion through which the imaging unit 30 passes is the imageable range D3. The imageable range D3 is a position that is limited when detecting continuous colors. This image pickup possible range D3 depends on the position where the image pickup unit 30 for picking up the image formed on the recording medium is attached to the carriage 5, but is attached to the position shown in FIGS. The recording head has a predetermined width at the center of the print width D2. This is a band-shaped range along the trajectory through which the imaging unit 30 attached to the carriage 5 passes, and this range corresponds to the imageable range D3. Since the range in which imaging can be performed is limited, it is not possible to select from locations other than the imaging range D3 when detecting continuous colors. Imaging may be unidirectional printing or reciprocating printing, and does not depend on a mark or character sequence. Even in the case of overprinting by a plurality of scans, it is possible to detect color fluctuations in order to select imaging data when it is determined as a continuous color. Therefore, it is possible to compare the image data in the middle of the overlap, and the image data at the last overlap after a plurality of scans can be used for the comparison.

  FIG. 8 is an explanatory diagram showing a use range of imaging data. In the figure, the horizontal direction is the main scanning direction, and the vertical direction is the sub-scanning direction. A continuous color area exists in the obtainable range D3. The width of the continuous color is determined in units of one pixel D4, and the minimum width determined to be a continuous color is defined as the minimum continuous color width D5. Further, the range used for obtaining the RGB values of the imaging data avoids a portion that may become noise around the matrix having the minimum continuous color width D5 (8 × 8 pixels in FIG. 8), and the imaging position. Only the captured image effective range D6 of the central portion of the matrix is used with a margin corresponding to the amount of deviation.

  Generally, when the imaging unit 30 moves during exposure, clear reading cannot be performed. However, in this system, imaging is performed while moving in the main scanning direction. Therefore, the length of one minimum continuous color width D5 in the main scanning direction is set to be longer than the distance traveled within the exposure time of the image sensor 31. As a result, there is only one color within the minimum continuous color width D5. Therefore, even if there is a movement during exposure and the captured image is blurred, there is no problem in obtaining the color. That is, the length of the minimum continuous color width D5 varies depending on the exposure time (shutter speed). By setting in this way, even if a captured image is blurred due to recording during high-speed movement, a portion that can be converted into an RGB value without any problem can be detected as a continuous color. When a high-speed shutter is used, that is, when the exposure time is short, it is possible to search for a continuous color with a smaller minimum continuous color width D5. Note that the range to be imaged during scanning is not square, but may be rectangular or elliptical.

  Each continuous color has position information (coordinates) and color information (RGB values) as data, and is stored in the memory 165 as continuous color data. Therefore, it is possible to detect color variations by comparing with RGB values of continuous color image data having the same color information, and it is possible to discriminate color variations of each color during recording.

  FIG. 9 is an explanatory diagram including a flowchart showing a continuous color ejection detection procedure.

In general, when recording with an ink-jet color printer, the recorded image data is decomposed to create color separation images of C (cyan), M (magenta), Y (yellow), and K (black), A color image is reproduced by ejecting the ink and superimposing it on the medium. More specifically, the image recording module 103 shown in FIG. 5 generates an ink ejection signal 104 from each CMYK color separation image.
The recording heads 21 to 24 have nozzles for each of the arrayed rows having an array number D7 of 1 to 300, and the ink ejection signal 104 is sent from each of the image recording modules 103 of FIG. The ink ejection signal 104 is information indicating 0 (none), 1 (small droplet), 2 (medium droplet), and 3 (large droplet). Each nozzle ejects ink based on the ink ejection signal 104.
Further, in the continuous color detection, the memory 165 of the control unit 160 stores the ink discharge signals 104 of the respective colors output from the image recording module 103. Information related to all of the nozzles 1 to 300 may be stored, but in the example, only the information of the imageable range D3 known in advance is stored in order to reduce the memory 165 (step S111). The imageable range D3 is determined by the mounting position of the imaging unit 30. Hereinafter, this stored information is referred to as nozzle ejection information of the imageable range D3.

  In the image compositing process, the nozzle discharge information of the imageable range D3 stored in step S111 is superimposed to detect a continuous identical color region formed on the recording medium (step S112). Hereinafter, this continuous identical color area is referred to as a “continuous area”.

  This continuous area may actually be synthesized with a color image on the memory 165, or may be the same color when the information on the amount of droplets of YMCK is substantially the same. For example, the same color is determined when the values of YMCK are 5% or less and the average value of the use range of the captured image effective range D6 in FIG. 8 is 3% or less. Judgment is made (step S113). The reason why the above judgment is given is that although the data is different when creating the color separation image, the recorded colors may be the same. Of course, the same color may be determined by a method different from the above method. That is, if it can be determined that the colors are the same, the method is not questioned. Furthermore, the determination criteria for the same color are not limited to the above.

  If it is determined in step S113 that the area is not a continuous area, it is temporarily stored in the memory 165 (step S114), and the process returns to step S112 to wait for superposition.

  In step S113, it is determined that areas of the same color are continuous. At that time, coordinate information is required. Therefore, position information in the main scanning direction and the sub-scanning direction is acquired. The position in the main scanning direction is obtained by counting the ink ejection signals 104 to the recording heads 21 to 24 from the beginning of one scan. For the position, the value of the encoder sensor 101 of the carriage 5 may be viewed. The sub-scanning position can be obtained from the nozzle array number.

  When sending the continuous color data 202, it is necessary to acquire the same position as the recording medium in the sub-scanning direction. The position is acquired from the sub-scanning encoder sensor 28.

  FIG. 10 is an explanatory diagram showing continuous color data and imaging data, and FIG. 11 is an explanatory diagram showing processing procedures for continuous color data and imaging data. FIG. 10 shows the distribution of data sorted by the color variation determination unit 205 by accumulating the continuous color data 202 and the imaging data 105 after imaging.

  First, there is continuous color data distributed with reproduction RGB values D11 of the same color. The sorted data D10 is data made up of continuous color data and imaging data, and the measured RGB value D12 of coordinates B: D9 of the imaging data having the same coordinates (30,485) as the coordinates A: D8 of the continuous color data. 095,0,0). Then, the measured RGB value D12 in the RGB values of each reproduced RGB value D11 is compared to determine the color variation.

  The data storage module 203 has the continuous color data 202 sent from the continuous color detection module 201 and the imaging data 105 sent from the imaging unit 30 as input values. Therefore, the image data 105 having the same coordinates B: D9 (30,485) as the coordinates A: D8 (30,485) of the continuous color data 202 is selected from the image data 105 sent (step S105). ). The continuous color data 202 and the selected imaging data 105 are sent to the color variation determination unit 205.

  When discarding unselected data, discard the unselected data in step S110. If there is a margin in the memory capacity, it may be discarded after image recording and color variation detection.

  FIG. 12 is a flowchart showing the procedure of the determination process of the color variation determination unit. In the figure, a color variation determination unit 205 receives continuous color data 202 and selected imaging data 105 from a data storage module 203. The received data is sorted for each reproduced RGB value D11 (step S201). The sorting result is a distribution image in FIG. Here, in order to determine the color variation, the imaging data 202 and the continuous color data 105 are sorted so that the color variation can be determined by a general detection method.

  Then, a value for comparison with the actual RGB value D12 is calculated by the actual RGB value comparison value calculation process (step S202). In this example, an average value of the actually measured RGB values 105 from the start of printing is taken and used as a comparison value with the next imaging data 202.

  In determining the color variation, the first acquired value is used as a reference value, and the reference value is compared with the calculated comparison value. If the difference value between the two exceeds a preset threshold value in the comparison, it is determined that there is color variation (step S106). This determination can also be made by looking at the variance of the difference values. The average value when two or more images of the same image are recorded takes an average value over a plurality of sheets from the start of recording, but in addition to this, color variations can be detected by comparing the average values of each sheet. Is possible. The threshold is measured and set in advance.

  If there is no color variation in step S106, the process returns to step S203 and the subsequent processing is repeated. If it is determined that there is color variation, the imaging data 105 determined as color variation is stored in the memory 165 for reporting (step S204).

  The color variation information is the coordinate D9 and its RGB value. In addition, the actually measured RGB value D12 sample number, average value, difference value from the average value, and the like can be stored. By accumulating color variation information in this way, it is possible to determine color variation every time a deviation occurs, or to determine color variation when a certain number of consecutive deviations occur. It becomes.

  If there are two or more records of the same image, the same continuous color data 202 is used to compare the same locations of the first and second image data, so that the continuous color is obtained from the second and subsequent sheets. It is also possible not to detect. Alternatively, recording may be interrupted immediately after the color variation is determined, and the test pattern may be printed from the next line, or may be printed on the margin of the paper for color correction. Note that color correction is executed by the control unit 160. Since the color correction itself is known, the description thereof is omitted in this embodiment.

  As described above, according to the present embodiment, a recorded image is picked up by the image pickup unit 30 immediately after ink discharge, and the continuous color coordinates and reproduction RGB values detected by the continuous color discharge detection module 201 and the image pickup unit 30 are picked up. The coordinates and measured values of the continuous colors thus held are held in the memory 165, and the color variations are judged during printing by comparing the held coordinates and the measured RGB values. Can be detected.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention, and all technical matters included in the technical idea described in the claims are included. The subject of the present invention. The above embodiment shows a preferable example, but those skilled in the art can realize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification, These are included within the scope defined by the appended claims.

21, 22, 23, 24 Recording head 30 Imaging unit 100 Printer 102 Image data 104 Ink ejection signal 165 Memory 200 Color variation detection system 201 Continuous color ejection detection module 205 Color variation determination unit

JP 2002-120388 A

Claims (11)

A color variation detection device that detects color variations of the same color,
Detecting means for detecting a predetermined range of the same color as a continuous color from an ink ejection signal generated from input image data;
An imaging unit that captures an image in which the continuous color is recorded by a recording unit that records an image on a recording medium based on the ink ejection signal, and acquires imaging data;
Determining means for comparing the measured values of the imaging data having the same position information as the continuous color data detected by the detecting means to determine color variation;
With
The color detecting device according to claim 1, wherein when the same information is recorded on a plurality of sheets, the detection means detects continuous colors using color information of continuous colors different from the first sheet. The color variation detection device according to claim 1,
Further comprising holding means for holding continuous color data detected by the detection means and imaging data imaged by the imaging means;
The determination means selects a continuous color position information and color information held in the holding means that correspond to the recording position to be determined, and compares the actual measurement values of the portions for which the same color recording instruction is given. A color variation detection apparatus for determining color variation during recording of one image. The color variation detection device according to claim 1,
The color variation detection apparatus characterized in that the determination means determines color variations of the second and subsequent sheets when the same information is recorded on a plurality of sheets. The color variation detection device according to any one of claims 1 to 3,
The color variation detection apparatus, wherein the determination unit determines a color variation between an image recording start and a recording end. The color variation detection device according to any one of claims 1 to 4,
The color variation detection apparatus according to claim 1, wherein the imaging unit moves integrally with the recording unit and performs imaging in parallel with a recording operation of the recording unit. An image forming apparatus comprising the color variation detection device according to claim 1. The image forming apparatus according to claim 6, wherein
A color correction unit;
When the determination means determines that there is color variation, the recording by the recording means is terminated, the test pattern is recorded from the next line, the test pattern is read, and the color correction means is based on the color of the read image. An image forming apparatus that performs color correction. The image forming apparatus according to claim 6, wherein
A color correction unit;
When the determination means determines that there is color variation, the recording by the recording means is terminated, a test pattern is recorded in the margin of the recording medium, the test pattern is read, and the color correction means is based on the color of the read image An image forming apparatus, wherein color correction is performed by the method. The image forming apparatus according to any one of claims 6 to 8,
A reporting means for reporting that color variation has occurred;
Immediately after the determination unit determines that there is color variation, the reporting unit reports that fact, and the recording unit interrupts image recording. A color variation detection control program for causing a computer to execute control for detecting and judging color variation of the same color,
A first procedure for detecting a predetermined range of the same color as a continuous color from an ink ejection signal generated from input image data;
A second procedure for capturing image data by capturing an image in which the continuous color is recorded by a recording unit that records an image on a recording medium based on the ink ejection signal;
A third procedure for determining color variation by comparing measured values of the imaging data having the same position information as the continuous color data detected in the first procedure;
With
In the first procedure, when the same information is recorded on a plurality of sheets, a continuous color is detected from the second sheet using color information of a continuous color different from the first sheet. program. A color variation detection control method for detecting color variation of the same color,
A first step of detecting a predetermined range of the same color as a continuous color from an ink ejection signal generated from input image data;
A second step of acquiring an image data by capturing an image in which the continuous color is recorded by a recording unit that records an image on a recording medium based on the ink ejection signal;
A third step of comparing a measured value of the imaging data having the same position information as the continuous color data detected in the first step to determine a color variation;
With
In the first step, when the same information is recorded on a plurality of sheets, a continuous color is detected from the second sheet using color information of a continuous color different from that of the first sheet. Method.