JP2014046647A - Image processor and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor capable of printing a bar code that is stably read without requiring complicated arithmetic processing and a large memory area.SOLUTION: An image processor provided with image formation means for performing image formation by performing image-like exposure of a photoreceptor by a light beam includes recognition means for recognizing the existence/absence of a bar code pattern in image data image-formed by the image formation means, exposure control means for controlling exposure power, and specification means for specifying the almost center of the minimum unit element constituting the bar code pattern when the maximum value of a diameter ω specified by the space size to be 1/estrength of peak strength of a light beam is equal to or greater than a pixel interval λ specified by a reciprocal of recording density, and the bar code pattern is recognized in the image data by the recognition means; and the exposure control means makes the exposure power small when exposing the almost center of the specified minimum unit element.

Description

  The present invention relates to an image processing apparatus and program for performing barcode printing.

  Conventionally, a one-dimensional barcode is well known as an identifier that represents a numerical value or a character depending on the thickness of a striped line. This one-dimensional barcode is used in various places such as merchandise management and logistics management. In recent years, two-dimensional codes that can express more information than one-dimensional barcodes are also used. Many of these bar codes are printed on a product package, but others are printed by a printer using a printer like a customer bar code in a postal service.

  In recent years, in order to represent more information with barcodes and to reduce the barcode printing area from the viewpoint of package design, the density of lines has been increased, such as drawing the line width of the barcodes as thin as possible. It has been. For example, in a barcode standard used in a convenience store fee proxy storage system such as UCC / EAN128 barcode, the line width of the barcode needs to be very narrow.

  By the way, in order to stably read a bar code with a very narrow line width, a high print quality that reproduces a bar code thin line by a printer engine or the like is desired. However, in an image forming apparatus that forms an electrostatic latent image on a photoconductor by optical writing, if the spot diameter of the light beam applied to the photoconductor is large, the reproduction of fine lines tends to be poor and collapse. On the other hand, if the exposure light amount to the photosensitive member is lowered, a problem of fading occurs. Therefore, stable reading performance by the scanner is not guaranteed.

  Patent Document 1 discloses an invention relating to an image forming apparatus that analyzes a drawing direction of a barcode pattern and controls an exposure apparatus based on the analysis result in order to print a barcode pattern with improved printing quality. Yes. Further, Patent Document 2 discloses an image forming apparatus that changes the width of each black line of a bar code based on the sum of the number of dots of white line width data on both sides of the black line in order to stabilize bar code reading performance. The invention is disclosed.

  However, the invention described in Patent Document 1 requires a separate process for analyzing the drawing direction of the barcode pattern. In the invention described in Patent Document 2, a process for changing the width of the black line based on the sum of the number of dots of the white line width data is separately required. Therefore, in the inventions described in Patent Document 1 and Patent Document 2, there is a problem that the arithmetic processing in printing the barcode pattern is complicated, and a large memory area is required to execute the complicated arithmetic processing.

  SUMMARY An advantage of some aspects of the invention is that it provides an image processing apparatus and a program that can print a barcode that can be stably read without requiring complicated arithmetic processing and a large memory area.

In order to solve the above problems, an image processing apparatus of the present invention is an image processing apparatus that includes an image forming unit that forms an image by exposing a photoconductor to an image with a light beam. Recognition means for recognizing the presence or absence of a barcode pattern in the formed image data, exposure control means for controlling the exposure power and / or pulse width of the light beam, and 1 / e ² intensity of the peak intensity of the light beam The minimum unit element constituting the barcode pattern when the maximum value of the diameter ω defined by the space size is not less than the pixel interval λ defined by the reciprocal of the recording density and the barcode pattern is recognized in the image data by the recognition means The exposure control means reduces the exposure power of the light beam when exposing the approximate center of the specified minimum unit element. And wherein the Kusuru.

Furthermore, in order to solve the above-described problems, the program of the present invention includes an image forming process for forming an image by exposing a photoconductor with a light beam and a presence or absence of a barcode pattern in image data to be formed. The maximum value of the diameter ω defined by the recognition process for recognition, the exposure control process for controlling the exposure power and / or the pulse width of the light beam, and the spatial size that is 1 / e ² of the peak intensity of the light beam is When the barcode pattern is recognized in the image data in the recognition process at a pixel interval λ or more defined by the reciprocal of the recording density, the computer performs a specific process for specifying the approximate center of the minimum unit elements constituting the barcode pattern. The exposure control process is a program to be executed, and the exposure power of the light beam is adjusted when exposing substantially the center of the specified minimum unit element. Characterized in that it comprises a process for fence.

  According to the present invention, it is possible to print a barcode that can be read stably without requiring complicated arithmetic processing and a large memory area.

1 is a schematic diagram illustrating a multifunction machine according to an embodiment of the present invention. It is a schematic diagram showing the functional block of the printer part of embodiment of this invention. It is a schematic diagram showing the functional block of GAVD of embodiment of this invention. It is a schematic diagram showing the process block in the image processing apparatus of embodiment of this invention. It is a schematic diagram showing an EAN-128 barcode. It is a schematic diagram showing the latent image electric field strength in the latent image before correction. FIG. 6 is a schematic diagram illustrating a pile height when toner is developed on a latent image having a latent image electric field intensity before correction. It is a schematic diagram showing the image data before and after correction | amendment by the image processing apparatus of embodiment of this invention. It is a schematic diagram showing the latent image after correction | amendment by the image processing apparatus of embodiment of this invention. It is a schematic diagram showing another image data before and after correction | amendment by the image processing apparatus of embodiment of this invention. It is a schematic diagram showing another image data before and after correction | amendment by the image processing apparatus of embodiment of this invention. It is a schematic diagram showing another image data before and after correction | amendment by the image processing apparatus of embodiment of this invention. It is a schematic diagram showing another image data before and after correction | amendment by the image processing apparatus of embodiment of this invention.

  Hereinafter, an image processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. However, the embodiment of the present invention is not limited to the following embodiment. In this embodiment, as an example of an image processing apparatus, an example in which a multifunction machine 1 having a complex function for handling images such as a copy, a facsimile, a scanner, and a print will be described.

  FIG. 1 shows a schematic configuration of a multifunction machine 1 according to the present embodiment. The multifunction device 1 shown in the figure includes an optical device 10 including optical elements such as a semiconductor laser element and a polygon mirror, a photosensitive drum 21, a charging device (not shown), an image forming unit 20 including a developing unit 22, and the like. And a transfer / fixing unit 30 including a fixing unit 33, a conveyance belt 31, an intermediate transfer belt 32, and the like.

  The optical device 10 includes a laser output unit (not shown). A light beam emitted from the laser output unit is collected by a cylindrical lens (not shown) and deflected to a reflection mirror 12 by a polygon mirror 11.

  In the present embodiment, the number of light beams L corresponding to each color of cyan (C), magenta (M), yellow (Y), and black (K) is generated. The photosensitive drums 21K to 21M to be exposed are imagewise exposed to form an electrostatic latent image.

The diameter ω of the exposure spot of the light beam L irradiated on the photosensitive drum 21 is, for example, in the main scanning direction and the sub-scanning direction depending on the spatial size in a range that is approximately 1 / e ² intensity of the central peak intensity of the light beam. Is defined. The effective resolution in each scanning direction of the multifunction device 1 depends on the diameter of the exposure spot. Hereinafter, the main scanning direction is defined as the light beam scanning direction, and the sub-scanning direction is defined as a direction orthogonal to the main scanning direction.

  The formed electrostatic latent image is conveyed to the developing unit 22 as the photosensitive drum 21 of each color rotates. The electrostatic latent image is developed with a developer, and a developer image is formed and carried on the photosensitive drum 21. The developer image is conveyed to the transfer / fixing unit 30 as the photosensitive drum 21 rotates. The transfer / fixing unit 30 includes sheet feeding cassettes 51, 52, 53, sheet feeding units 61, 62, 63, a vertical conveyance unit 31, a conveyance belt 31, and a fixing unit 33.

  Further, transfer members such as high-quality paper and plastic sheets stacked on the paper feed cassettes 51, 52, 53 are fed by the paper feed units 61, 62, 63, respectively, and the photosensitive drum 21 is fed by the vertical transport unit 31. It is conveyed to a position where it abuts on the surface.

  The developer images on the photosensitive drums 21 for the respective colors are transferred to a transfer member electrostatically attracted to the conveyance belt 31 under a transfer bias potential. After the transfer, the transfer member on which the image is formed is supplied to the fixing unit 33. The fixing unit 33 includes a fixing member such as a fixing roller including silicone rubber, fluorine rubber, and the like. The fixing unit 33 pressurizes and heats the transfer member and the multicolor developer image, and the formed image is placed on the transfer member. Let it settle. The heat treatment at the time of fixing includes a possibility of causing a minute shrinkage on the transfer member.

  The fixed printed matter is discharged onto a discharge tray 80 by a discharge unit 40. When performing double-sided printing, the printed material is conveyed to the double-sided printing paper supply unit 70 without being guided onto the paper discharge tray 80 by setting the separation claw 41 on the upper side. Thereafter, the printed material conveyed to the duplex printing paper supply unit 70 is re-fed to transfer the image to the back surface. The double-sided printed material on which images are formed and fixed on both sides is discharged onto the discharge tray 80 by setting the separation claw 41 on the lower side.

  Next, schematic functional blocks of the printer unit 100 as an image forming unit in the multifunction machine 1 according to the present embodiment will be described with reference to FIG. The printer unit 100 includes a GAVD (Gate Array Video Driver) 110 that comprehensively controls the entire printer unit 100 according to the image data P, and a current for driving the semiconductor laser device by a signal output from the GAVD 110. An LD (Laser Diode) driver 120 to be supplied to a laser diode and a LD unit 130 which mounts a semiconductor laser element and forms an electrostatic latent image on the photosensitive drum 21 are configured.

  Furthermore, a more detailed functional block of the GAVD 110 will be described with reference to FIG. The GAVD 110 includes a memory block 111 that stores input image data. The GAVD 110 performs speed conversion and format conversion on the input image data, and passes the converted image data to the image processing unit 112. The image processing unit 112 reads the image data P from the memory block 111 and executes resolution conversion processing, screen processing, and the like of the image data P.

  Further, functional blocks of the image processing unit 112 will be described with reference to FIG. The image processing unit 112 includes a barcode pattern extraction unit 1121 that extracts a barcode pattern, a correction position specifying unit 1122, and a parameter storage unit 1123. The image processing unit 112 performs correction processing on the barcode pattern for the original image data acquired from the memory block 111, and outputs the processed image data to the output data control unit 113.

  When the image processing unit 112 determines that the barcode pattern is included in the image data, the correction position specifying unit 1122 specifies the approximate center of the smallest cell constituting the barcode pattern, and the position of the position is determined. The image data is changed so that the exposure energy is changed.

  The parameter storage unit 1123 stores a look-up table 11231 (LUT: Look Up Table) that associates an optimal correction amount according to, for example, the minimum barcode cell, resolution, and development conditions. The correction position specifying unit 1122 changes the image data so that the optimum exposure energy is obtained based on the characteristic value obtained from the lookup table 11231.

  In the image data P, a position where the photosensitive drum 21 is exposed is defined by a main scanning line address value defined in the main scanning direction and a sub scanning line address value defined in the sub scanning direction. .

  The output data control unit 113 generates a drive control signal corresponding to the image data P generated by the image processing unit 112 and transmits it to the LD driver 120. The LD driver 120 that has received the drive control signal drives the LD unit 130 according to an operation clock in which a phase is set for each scan line by a drive control signal corresponding to the image data P and a PLL (Phase Locked Loop) 140. By controlling the light emission time of the semiconductor laser element, the electrostatic latent image on the photosensitive drum 21 is controlled for each main scanning line.

  Next, a processing block as a superordinate concept of each functional block described above in the image processing apparatus of the present embodiment will be described with reference to FIG. The processing block of this embodiment includes an image forming unit 201 that executes image forming processing based on predetermined image data, a barcode recognition unit 202 that recognizes whether or not a barcode pattern is included in the image data, a barcode It comprises a specifying unit 203 that specifies the substantially central part of the minimum unit element of the code pattern, and an exposure control unit 204 that controls the exposure power and pulse width in the exposure apparatus.

  The image forming unit 201 is a processing block that causes an image forming mechanism such as an exposure device, a developing device, and a photosensitive member to form an image based on image data read by a scanner. For example, the printer unit 100 described above corresponds to this.

  The barcode recognition unit 202 corresponds to, for example, the barcode pattern extraction unit 1121 described above, and the specifying unit 203 corresponds to the correction position specifying unit 1122 described above. The exposure control unit 204 corresponds to the output data control unit 113 described above, for example.

  Next, the details of this embodiment will be described by taking an example of printing an EAN-128 barcode at 600 dpi. The EAN-128 barcode consists of three bars and three spaces for one character. When printing at a resolution of 600 dpi, the width of one bar is generally composed of four types of combinations of 4 dots × n (n = 1 to 4). The width of the space is the same as the bar. The case where n = 1 is referred to as a minimum module. At 600 dpi, the width of the bar when n = 1 is about 0.169 mm.

  As shown in FIG. 5, for example, the bar pattern indicating “A” in CodeA is “BSBSBS = 1111323”. Bars (B) and spaces (S) appear alternately.

  FIG. 6 is a schematic diagram showing the state of the latent image electric field intensity when writing is performed on the photosensitive member without performing correction processing on the bar of the minimum module. In the figure, the thick line represents the latent image electric field strength 302 of the bar, and the thin line represents the latent image electric field strength 301 of one line.

  When the toner is developed on the latent image having the electric field strength as shown in FIG. 6, it is easily affected by the large number of modules in the adjacent space, and the edge effect that the line width of the bar becomes thick is shown in FIG. 7. As shown, the pile height of toner T increases. Then, the toner T having a high pile height is crushed by heat fixing, so that the bar becomes thick, and the space between the bars may be crushed and cannot be resolved. Therefore, in the present embodiment, the writing of the pixels at the center of the bar is changed in order to eliminate the collapse of the space.

  FIG. 8 shows a correction example in which the writing of the pixel at the center of the bar is changed. FIG. 8 shows “BSBS = 1113” as a part of the bar pattern. Pixels are indicated by “□”, and an image of the image data is shown as a two-dimensional array of pixels. “□” with a numerical value represents a bar, and “□” without a numerical value represents a space. The numerical value described in “□” represents the exposure intensity at the time of exposure. If the exposure intensity is high, a deep latent image is formed.

  FIG. 8A illustrates the image data before correction, and FIG. 8B illustrates the image data corrected to prevent the space from being crushed. The resolution of these images is 600 dpi (dot per inch). Note that the resolution is defined by the number of pixels per unit length and may or may not be the same in the main scanning direction and the sub-scanning direction. For convenience of explanation, the same embodiment will be described as an example.

  In the corrected image data shown in FIG. 8B, the exposure intensity at the approximate center position of the image area corresponding to the bar is smaller than usual. That is, when the exposure intensity at the approximate center position of the image area corresponding to the bar before correction is “100”, it is “50” after correction.

  The approximate center of the image area indicates a pixel position near the center of the image area. When the image area has an even pixel length with respect to the short side of the bar, the position where the image area is just bisected, When the pixel length is an odd number, the quotient obtained by dividing the pixel length M by 2 is defined as Q, and the image region is defined by a position that is divided into Q pixels and (M−Q) pixels. Here, the exposure intensity of the center two pixels of the bar is corrected, but the exposure intensity of one pixel may be corrected. Note that the number of pixels to be corrected around the approximate center of the bar varies depending on development conditions and the like.

  FIG. 9 shows a latent image diagram after correction with respect to the latent image diagram before correction shown in FIG. As shown in the figure, after correction, the latent image is shallower, and the toner adhesion amount is reduced and the pile height is lowered even under the same development conditions. As a result, a bar code that can be read stably without forming toner in the space between the bars after fixing is formed.

  In the present embodiment, the exposure intensity correction by the exposure control unit 204 may be performed by controlling the exposure power, or may be performed by controlling the pulse width. That is, in the above example, the exposure intensity at the approximate center position of the image area corresponding to the bar is corrected by reducing the exposure power and the pulse width.

  FIG. 10 shows a correction example when the bar width n = 2 or more. In this figure, the case where n = 3 is illustrated. As shown in the figure, here, the corrected minimum modules are connected continuously. The exposure intensity at the approximate center position of the image area corresponding to the bar is smaller than usual. Again, when the exposure intensity at the approximate center position of the image area corresponding to the bar before correction is “100”, it is “50” after correction.

  Next, the case of a two-dimensional barcode will be described. A so-called QR code (registered trademark, developed by Denso Wave) is a typical two-dimensional barcode. The QR code (registered trademark) is represented by a set of one square area constituting the QR code (registered trademark) called a cell. The larger this cell, the easier it is to read by a scanner that reads the QR code (registered trademark). On the other hand, the QR code (registered trademark) requires a large print area because the code size is large. Usually, it is recommended to print at 4 dots or more per cell, and when printing at 4 dots at a resolution of 600 dpi, the cell size is about 0.169 mm.

  FIG. 11 shows an example of correction in the QR code (registered trademark). FIG. 11A shows image data before correction, and FIG. 11B shows image data corrected to prevent crushing. As shown in the figure, it can be seen that the exposure intensity of the pixel at the approximate center of the cell is smaller than usual after correction. Specifically, the exposure intensity of the pixel at the approximate center of the cell is “100” before the correction, but the exposure intensity of the pixel at the approximate center of the cell is “60” after the correction. In other words, as in the case of the one-dimensional barcode described above, the latent image is not deepened after correction even in the two-dimensional barcode, the pile height of the toner under the same development conditions is reduced, and the crushing at the time of fixing is eliminated. Is done.

[Example 1]
In this embodiment, a reading experiment for evaluating the reading stability of the barcode before and after the correction of the exposure intensity was performed. In Example 1, a model equivalent to imgio Neo C285 (registered trademark) developed by the applicant as a printer employing an electrophotographic system was used for image formation. Furthermore, in the main scanning direction 1 / e ² diameter of about 60 [mu] m as a printer, it was used with a light beam diameter in the sub-scanning direction 1 / e ² diameter of about 60 [mu] m.

  For image formation, image data having an EAN-128 barcode with a resolution of 600 dpi and a bar width of about 0.169 mm and a bar pattern of “111323” was used. In this case, the pixel interval λ is 2.54 cm / 600 dpi = about 42 μm as the reciprocal of the recording density. FIG. 12 schematically shows the bar image data before and after correction. FIG. 12A shows image data before correction, and FIG. 12B shows image data after correction. As shown in FIG. 12B, it can be seen that the exposure intensity for two pixels at the center of the bar decreases from “100” to “70” after correction.

That is, in the present embodiment, in the case of Example 1 described above, the maximum value (60 μm) of the diameter ω defined by the spatial size that is 1 / e ² of the peak intensity of the light beam is the reciprocal of the recording density. When the pixel interval λ (42 μm) or more defined by the above, that is, when the irradiated light beam diameter is larger than the pixel interval, the approximate center of the bar as the minimum unit constituting the bar pattern is specified. When exposing the approximate center, the output data control unit 113 reduces the exposure power or pulse width of the light beam.

[Example 2]
Further, in Example 2, as in Example 1, a model equivalent to imgio Neo C285 (registered trademark) was used for image formation. Further, in the same manner as in Example 1, the main scanning direction 1 / e ² diameter of about 60 [mu] m as a printer, was used with a light beam diameter in the sub-scanning direction 1 / e ² diameter of about 60 [mu] m.

  On the other hand, in the second embodiment, image data with a version 1 QR code (registered trademark), a resolution of 600 dpi, a cell of 4 dots, and a cell size of about 0.169 mm was used for image formation. That is, in Example 2, the light beam diameter (60 μm) is larger than the pixel interval (42 μm). FIG. 12 schematically shows the cell image data before and after correction. FIG. 12A shows image data before correction, and FIG. 12B shows image data after correction. As shown in FIG. 12B, it can be seen that the exposure intensity for the four pixels at the center of the cell decreases from “100” to “60” after correction.

Example 3
Further, in Example 3, as in Example 1, a model equivalent to imgio Neo C285 (registered trademark) was used for image formation. On the other hand, unlike Example 1, a printer having a light beam diameter of 1 / e ² diameter of 30 μm in the main scanning direction and 1 / e ² diameter of 30 μm in the sub scanning direction was used. Unlike Example 1, image data of EAN-128 bar pattern “111323” having a resolution of 1200 dpi and a bar width of about 0.169 mm was used. In this case, the pixel interval λ is 2.54 cm / 1200 dpi = about 21.17 μm as the reciprocal of the recording density. That is, in Example 3, the light beam diameter (30 μm) is larger than the pixel interval (21.17 μm).

[Comparative Example 1]
Subsequently, in Comparative Example 1, as in Example 1, a model equivalent to imgio Neo C285 (registered trademark) was used for image formation. On the other hand, unlike Example 1, a printer having a light beam diameter of 1 / e ² diameter of 30 μm in the main scanning direction and 1 / e ² diameter of 30 μm in the sub scanning direction was used. For image formation, the image data of the bar pattern “111323” was used with an EAN-128 barcode having a resolution of 600 dpi and a bar width of about 0.169 mm as in the first embodiment. That is, in this comparative example 1, the pixel interval (42 μm) is larger than the light beam diameter (30 μm).

[Comparative Example 2]
Further, in Comparative Example 2, the model used for image formation and the used image data are the same as in Example 2. However, unlike Example 2, the main scanning direction 1 / e ² diameter is 30 μm and the sub-scanning direction is 1 as a printer. / E ² Diameter having a light beam diameter of 30 μm was used. That is, in this comparative example 2, the pixel interval (42 μm) is larger than the light beam diameter (30 μm).

  Table 1 shows the evaluation results of the reading stability of each barcode printed in Examples 1 to 3 and Comparative Examples 1 and 2 divided before and after correction. In the evaluation, a barcode reader with a resolution of 0.1 mm was used for reading each barcode. Also, for evaluation, three types of bar codes with different contents are output. If all three types have no reading error, “○” (correction effect) is indicated. If one type of reading error occurs, “×” ( No correction effect). Note that the reading error includes both of the above-described crushing and blurring.

  As shown in Table 1, in Example 1, a reading error occurred before the correction of the exposure intensity, but no error occurred after the correction. Also in Example 2, a reading error occurred before the correction of the exposure intensity, but no error occurred after the correction. Furthermore, in Example 3, a reading error occurred before the correction of the exposure intensity, but no error occurred after the correction. That is, in all of the first to third embodiments, the light beam diameter is larger than the pixel interval. Therefore, when the approximate center of the bar or cell is exposed, the output data control unit 113 corrects the light beam exposure power and pulse width to be small. A correction effect can be obtained and collapse can be prevented.

  On the other hand, in both Comparative Example 1 and Comparative Example 2, there was no reading error before the correction of the exposure intensity, but a reading error occurred after the correction. That is, in Comparative Examples 1 and 2, there is no need to correct the pixel spacing because it is originally larger than the light beam diameter. In this case, if the output power control unit 113 corrects the exposure power and pulse width of the light beam to be small, Occurs, that is, the correction effect cannot be obtained.

  Each of the above-described embodiments is a preferred embodiment of the present invention, and various modifications can be made without departing from the scope of the present invention. Up to this point, an image processing apparatus (multifunction peripheral) having a plurality of functions has been described as an example of an image processing apparatus. However, in another embodiment of the present invention, the image processing apparatus can be configured as another image forming apparatus such as a copying machine or a laser printer. In still another embodiment, the image processing apparatus can be configured as a semiconductor device such as an LSI chip including the image processing unit.

  The above functions can be realized by a computer-executable program written in a programming language such as an assembler or C language. ROM, EEPROM, EPROM, flash memory, flexible disk, CD-ROM, CD-RW, DVD, SD It can be stored in a device-readable recording medium such as a card or MO and distributed.

DESCRIPTION OF SYMBOLS 1 Multifunctional device 10 Optical apparatus 11 Polygon mirror 12 Reflecting mirror 20 Image forming unit 21 Photosensitive drum 22 Developing unit 30 Transfer / fixing unit 31 Conveying belt 32 Intermediate transfer belt 33 Fixing unit 40 Paper discharging unit 41 Separating claw 51-53 Paper feeding Cassettes 61 to 63 Paper feed unit 70 Paper feed unit for double-sided printing 80 Paper discharge tray 100 Printer unit 110 GAVD
111 Memory Block 112 Image Processing Unit 113 Output Data Control Unit 120 LD Driver 130 LD Unit 140 PLL
DESCRIPTION OF SYMBOLS 201 Image formation part 202 Barcode recognition part 203 Specification part 204 Exposure control part 1121 Barcode pattern extraction part 1122 Correction position specification part 1123 Parameter memory | storage part 11231 Lookup table

Japanese Patent No. 4553000 JP 2010-089482 A

Claims (8)

An image forming apparatus including an image forming unit that forms an image by exposing the photosensitive member to an image with a light beam,
Recognizing means for recognizing the presence or absence of a barcode pattern in image data formed by the image forming means;
Exposure control means for controlling exposure power and / or pulse width of the light beam;
The maximum value of the diameter ω defined by the spatial size that is 1 / e ² intensity of the peak intensity of the light beam is equal to or larger than the pixel interval λ defined by the reciprocal of recording density, and the image data is added to the image data by the recognition unit. When the barcode pattern is recognized, a specifying means for specifying the approximate center of the minimum unit elements constituting the barcode pattern,
The image processing apparatus, wherein the exposure control means reduces the exposure power of the light beam when exposing the approximate center of the specified minimum unit element.   The image processing apparatus according to claim 1, wherein the exposure control unit reduces a pulse width of the light beam when exposing a substantially center of the specified minimum unit element.   3. The identification unit according to claim 1, wherein when the one-dimensional barcode is recognized in the image data by the recognition unit, the identification unit identifies a substantially center of a minimum module constituting the one-dimensional barcode. Image processing apparatus.   3. The specification unit according to claim 1, wherein when the two-dimensional barcode is recognized in the image data by the recognition unit, the identification unit specifies a substantially center of a minimum module constituting the two-dimensional barcode. Image processing apparatus. An image forming process for forming an image by exposing the photoconductor to an image with a light beam;
Recognition processing for recognizing the presence or absence of a barcode pattern in image data to be imaged;
Exposure control processing for controlling exposure power and / or pulse width of the light beam;
The maximum value of the diameter ω defined by the spatial size that is 1 / e ² intensity of the peak intensity of the light beam is not less than the pixel interval λ defined by the reciprocal of the recording density, and the image data is included in the image data in the recognition process. When a barcode pattern is recognized, a program for causing a computer to execute a specific process for specifying the approximate center of the minimum unit elements constituting the barcode pattern,
The exposure control process includes a process of reducing the exposure power of the light beam when exposing the approximate center of the specified minimum unit element.   6. The program according to claim 5, wherein the exposure control process includes a process of reducing a pulse width of the light beam when exposing the approximate center of the specified minimum unit element.   6. The specifying process includes a process of specifying an approximate center of a minimum module constituting the one-dimensional barcode when the one-dimensional barcode is recognized in the image data in the recognition process. Or the program of 6.   6. The specifying process includes a process of specifying a substantially center of a minimum module constituting the two-dimensional barcode when a two-dimensional barcode is recognized in the image data in the recognition process. Or the program of 6.

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