JP3951628B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus used for a copying machine, a printer, or the like.
[0002]
[Prior art]
Conventionally, in a print image inspection apparatus of an image forming apparatus such as a copying machine or a printer, a print image formed on a recording medium is read by an optical image reading apparatus using a linear image sensor or an area image sensor, and converted into electronic data. By performing the conversion, the quality of the print image is determined by comparing and collating with the electronic data of the original image.
[0003]
However, when the print image recorded on the recording medium is read, the electronic data read from the print image is not consistent if the recording medium transport means has uneven speed, or the recording medium itself is misaligned, tilted or fluttered. Since these are reflected, there is a problem that the inspection accuracy is lowered even if the electronic data of the original image is directly compared and verified.
[0004]
In order to solve this problem, for example, in JP-A-10-51628 and JP-A-10-248013, a visible position reference mark such as a registration mark or a ladder pattern is recorded in a non-image area of a recording medium. The position reference mark is read at the same time as the print image recorded in the image area, and the position deviation amount, inclination amount, distortion amount, etc. of the print image are calculated based on the position coordinates of the position reference mark, and the position deviation amount is corrected. A technique for comparing and collating the electronic data with the electronic data of the original image is disclosed.
[0005]
If this technique is used, there is an advantage that it is possible to easily correct misalignment during reading of the recording medium during inspection.
[0006]
[Problems to be solved by the invention]
However, in the techniques disclosed in Japanese Patent Laid-Open Nos. 10-51628 and 10-248013, the position reference mark is printed only in the non-image area and not printed in the image area. It is difficult to effectively correct the influence of local distortion caused by a partial magnification variation of the optical system to be read or fluttering of an image area to be inspected.
[0007]
In addition, although the position reference mark is an unnecessary mark for the user, it is recorded so as to be visible so that there is a problem that it becomes annoying.
[0008]
In view of the above circumstances, the present invention is read and converted by the geometric distortion caused by the above-described reason when reading an inspection image (print image) from an image area of a recording medium on which a print image is recorded. The amount of distortion contained in the electronic data is calculated from a coordinate scale that is difficult to visually record, the amount of distortion contained in the read inspection data is corrected, and the printed image is judged with high accuracy. An object of the present invention is to provide an image forming apparatus that can be used.
[0009]
[Means for Solving the Problems]
An image forming apparatus according to a first aspect of the present invention that achieves the above object is an image forming apparatus that records a print image on a recording medium based on image data representing an original image. An image reading means for reading the inspection data representing the print image on the recording medium and the position data representing the coordinate scale from the recording medium on which the print image is recorded; A strain calculation means for obtaining the distortion of each region on the recording medium based on the position data read by the reading means, and the distortion obtained by the distortion calculation means for the inspection data obtained by the distortion calculation means and the image data. And determining means for determining whether or not the print image matches the image data by collating in consideration of
[0010]
An image forming apparatus of a second invention that achieves the above object is an image forming apparatus that records a print image on a recording medium based on image data representing an original image, and records the print image on the recording medium. A recording unit that records a difficult-to-view coordinate scale using the same exposure optical system as that used to record the print image, and an inspection that represents the print image on the recording medium from the recording medium on which the print image and the coordinate scale are recorded Image reading means for reading data and position data representing coordinate scales separately from each other, distortion calculating means for obtaining distortion of each area on the recording medium based on the position data read by the image reading means, and the distortion By comparing the inspection data obtained by the calculation means with the image data in consideration of the distortion obtained by the distortion calculation means, the print image is obtained. There characterized by comprising a judging means for judging whether or not consistent with the image data.
[0011]
Here, the coordinate scale of the recording medium of the first and second inventions is formed by a recording material including an infrared absorbing material, and the image reading unit emits light having a wavelength including an infrared region. The recording medium is irradiated with the light from the emitted light source, and the reflected light from the coordinate scale is extracted based on the difference between the reflected light intensity from the coordinate scale and the reflected light intensity from the print image. It is preferable to convert the reflected light from the print image into inspection data as well as the position data.
[0012]
The coordinate scales of the recording media of the first and second inventions are recorded by a recording material including a fluorescent material, and the image reading unit includes light receiving elements having different sensitivities for the three primary colors. A light source that emits light having a wavelength including an ultraviolet region, and extracts the light received from the coordinate scale by irradiating the recording medium with light from the light source, and converts the light into position data; It is also a preferable aspect that the received light is converted into inspection data.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The first embodiment of the image forming apparatus of the first invention will be described below.
[0014]
FIG. 1 is a schematic configuration diagram showing a first embodiment of the image forming apparatus of the present invention.
[0015]
The image forming apparatus shown in FIG. 1 determines an image forming unit 50 that forms a print image on a sheet, a paper feed / conveying unit 51 that supplies and conveys the sheet, and determines whether the print image is good and the sheet that has been printed. A finishing processing unit 52 that classifies a good print image for each page, a print image creation unit 53 that performs image processing or pulse modulation on image data, and a print image printed on paper and a coordinate scale are read. Is converted into inspection data and position data, corrected inspection data is corrected with position data, corrected inspection data is obtained, and compared with the image data and read to determine whether the printed image matches the original image Based on the determination result of the determination unit 54 and the reading determination 54, paper on which defective printing has been performed is excluded, or reprinting is instructed to the image forming unit 50. And a printer controller 55..
The print image creating unit 53 performs image processing on the image data raster-converted from the original image created by a personal computer or the like, or the image data read from the original image by the scanner, and binarizes and pulse-modulated the signal. It is generated and transmitted to the laser exposure device 56 of the image forming unit 50.
[0016]
The image forming unit 50 includes a photosensitive drum 57 on which a toner image is formed. The charger 59 uniformly charges the photosensitive drum 57, and the laser exposure device 56 is generated by the print image creating unit 53. The photosensitive drum 57 that is uniformly charged with the laser light pulse-modulated based on the signal is irradiated to form an electrostatic latent image, and the developing device 58 converts the electrostatic latent image formed on the photosensitive drum 57 into toner. To develop a toner image on the surface of the photosensitive drum 57. The toner image formed on the surface of the photosensitive drum 57 is transferred onto the paper 61 conveyed from the paper feed conveyance unit 51 to the printing position 60, and the fixing device 62 heats the transferred toner image on the paper 61. And pressurize and fix to make a printed image. The paper on which the print image is formed is conveyed to the print image reading position 63 by the paper feed conveyance unit 51.
[0017]
The paper feeding / conveying section 51 has three paper trays 64 that supply sheets of different sizes depending on the size of the image to be printed. Further, single-sided printing has been completed when printing on both sides of the sheet. A double-sided tray 65 for temporarily storing paper is provided. The paper stored in each tray is placed on a line of a paper transport belt 67 that is circulated and driven by a paper transport roller 66, and is fixed at a print position 60, a fixing position at a fixing device 62, and a print image reading position. A sheet that has been printed on one side but is printed on the other side is printed on the duplex tray 65, and a sheet that has been printed on both sides or a sheet that is printed on only one side is further divided into pages. It is conveyed to the processing unit 52 or a purge tray 68 that accommodates defective prints.
[0018]
The reading determination unit 54 is arranged at the print image reading position 63, and the area recorded on the paper in all the areas where the print image is formed on the paper and the characters or figures of the print image that has been fixed on the paper. The coordinate scales representing the positions of these are optically read and converted into inspection data and position data, respectively. Further, the amount of misalignment of the sheet at the print image reading position 63 is calculated based on the position data, and the inspection data is corrected based on the amount of misalignment to obtain corrected inspection data in which the amount of misalignment is corrected. Then, the image data input from the print image creation unit 63 is compared and collated with the corrected inspection data, and it is determined whether or not the print image matches the original image.
[0019]
Here, the reading determination unit 54 compares and collates with the image data after obtaining the corrected inspection data obtained by correcting the inspection data, but directly compares and collates the inspection data with the image data in consideration of the positional deviation amount. You can also
[0020]
If the result of the comparison and collation by the reading determination unit 54 is that the print image is determined not to have a character or graphic image that is inconsistent with the original image or a stain, the printer controller 55 prints the print image based on the determination information. The paper is determined to be inconsistent and is accommodated in the purge tray 68, and an image formation command is issued to the print image creating unit 53 so that the print image determined to be inconsistent is reprinted to obtain a good print image.
[0021]
In this way, the inspection data is subjected to the process of correcting the distortion amount of the recording medium, and it is determined whether or not the print image matches the original image, so that highly accurate determination is possible, and the highly accurate determination result is obtained. Based on this, defective prints are eliminated, and good alternative prints are formed again and accommodated in a predetermined sorting shelf, so that manual checks can be eliminated.
[0022]
In the present embodiment, an electrophotographic recording type image forming apparatus has been described. However, the image forming apparatus is not limited to an electrophotographic recording type, and may be a thermal recording type image forming apparatus. It may be a device or a printing device. The image forming apparatus may be a printer or a copier.
[0023]
FIG. 2 is a diagram illustrating functions of the image forming apparatus according to the first embodiment.
[0024]
In FIG. 2, a print image creating unit 53 generates image data by raster conversion from an original image created by a personal computer or the like, or reading from the original image by a scanner, and an image forming unit 50 is based on the image data. Record the print image on the paper.
[0025]
Here, coordinate scales representing the coordinate position of each area are printed in advance on all the image areas of the paper on which the print image is recorded so as to be hardly visible to the naked eye using ink containing an infrared absorbing material. Yes. The coordinate scale will be described later.
[0026]
The print image creation unit 53 includes a frame memory 71 that temporarily stores the image data 70, and a preprocessing unit that performs shading correction, noise removal, pixel value binarization processing, and the like on the image data 70 temporarily stored in the frame memory 71. 73, there is an original image memory 74 for storing the binarized image data processed by the preprocessing unit 73.
[0027]
The reading determination unit 54 includes a light source that irradiates light on all image areas of the paper and a sensor that converts reflected light received from the coordinate scale into position data, and converts reflected light received from the print image into inspection data. A scanner unit 68, a frame memory 81 that temporarily stores the position data converted by the scanner unit 68 and the inspection data 80, a distortion amount of the paper is calculated based on the position data, and the inspection data is corrected based on the distortion amount. The geometric distortion correction unit 82 that obtains corrected inspection data by the above, the preprocessing unit 83 that performs shading correction, noise removal, pixel value binarization processing, etc. on the corrected inspection data, and binarization processed by the preprocessing unit 83 There is a print image memory 84 for storing the corrected inspection data. In addition, there is an inspection unit 85 that extracts the image data 53 stored in the original image memory 74 of the print image creation unit 53 and the correction inspection data stored in the print image memory 84, and the inspection unit 85 extracts the corrected inspection. Data and image data are compared and collated to determine whether the print image matches the original image.
[0028]
Here, the light source of the scanner unit 69 uses an LED that emits light in the near-infrared region having a peak wavelength of light intensity of 880 nm, but is not limited thereto.
[0029]
In addition, the reflected light from the coordinate scale and the reflected light from the printed image are simultaneously incident on the sensor.
[0030]
FIG. 3 is a diagram illustrating an example of a recording medium on which a coordinate scale is printed in advance, which is used in the first embodiment.
[0031]
The recording medium shown in FIG. 3 is, for example, white printing paper, and at least one side of the print image forming area is made of ink containing an infrared absorbing material, and a grid scale 86 having a line width of, for example, 500 microns is highly accurate. It is printed.
[0032]
Here, for the sake of convenience, the grid scale 86 is recorded so that it can be seen with the naked eye, but in practice, it is almost invisible. The coordinate scale is not limited to a grid scale, and can be arbitrarily selected from an orthogonal coordinate scale, an oblique coordinate scale, a polar coordinate scale, and the like.
[0033]
FIG. 4 shows spectral reflectance characteristics of a color material containing an infrared absorbing ink including an infrared absorbing material used for recording a grid scale in the first embodiment and a carbon black used for recording a print image. FIG.
[0034]
In FIG. 4, the vertical axis represents the light reflectance (%), and the horizontal axis represents the wavelength (nm) of the irradiated light.
[0035]
The solid line in the figure represents the spectral reflectance characteristic curve of the carbon black coloring material, the alternate long and short dash line represents the spectral reflectance characteristic curve of the infrared absorbing ink, and the dotted line represents the spectral reflectance characteristic curve of the paper background. Appears.
[0036]
As can be seen from FIG. 4, the print image using the carbon black coloring material has a substantially constant reflectance and a low reflectance from the visible region to the near infrared region, and the background of the paper is close to the visible region. The reflectance is almost constant up to the infrared region and is high.
[0037]
The grid scale using infrared absorbing ink has a substantially constant reflectivity and high reflectivity in the visible region where the wavelength is 600 nm or less, and absorbs little light, but the wavelength ranges from 600 nm to 800 nm. Since the reflectance decreases while drawing a logistic curve, the property of absorbing light appears when the wavelength is in the near infrared region of 700 nm or more. Therefore, a grid scale using infrared absorbing ink is almost colorless and transparent in the visible region, and is difficult to visually recognize.
[0038]
FIG. 5 is a diagram illustrating spectral sensitivity characteristics of a CCD linear image sensor used as a sensor of the image reading unit.
[0039]
In FIG. 5, the vertical axis represents the relative sensitivity of the sensor, and the horizontal axis represents the wavelength of light.
[0040]
As can be seen from the figure, this CCD linear image sensor has a wavelength region in which the relative sensitivity reaches a peak from 500 nm to 600 nm, and there is a base portion where the relative sensitivity gradually decreases on both sides of the peak wavelength region. Since the sensitivity of the sensor ranges from 400 nm to 1000 nm, the wavelength region of the light irradiated from the light source is limited to, for example, 800 nm to 900 nm, so that an image printed with ink containing an infrared absorbing material can be obtained. Can be caught.
[0041]
FIG. 6 shows the position data and inspection data obtained by irradiating light from the LED having a peak intensity of 880 nm onto the paper used for printing in this embodiment and receiving the reflected light by the CCD linear image sensor and converting it. It is a figure which shows a signal level.
[0042]
In FIG. 6, the vertical axis represents the signal level (−) based on the background portion of the paper, and the horizontal axis represents the position on the paper on which coordinate scales, characters, or figures are recorded.
[0043]
The solid lines in the figure represent the signal levels of the coordinate scale portion and the print image portion based on the background portion of the paper.
[0044]
The signal level changes to a rectangular shape at the position where the coordinate scale is recorded on the sheet and the position where the print image is recorded, and the rectangular base 87 has a signal level of the coordinate scale and a signal level of the print image, respectively. Appears.
[0045]
As is apparent from the figure, the signal level of the coordinate scale is about half of the signal level of the print image.
[0046]
As described with reference to FIG. 4, in the wavelength region from 800 nm to 900 nm, the reflectance of the infrared absorber recording the coordinate scale is about 35%, and the carbon black-containing color material recording the print image Therefore, since the reflected light from the coordinate scale is stronger than the reflected light from the printed image, the signal level expressed by the negative polarity is larger in the printed image than the coordinate scale.
[0047]
In this way, since the print image portion and the coordinate scale portion can be read separately, the reflected light received from the coordinate scale is converted into position data, and the reflected light received from the print image is converted into inspection data. Can do.
[0048]
Further, since the amount of distortion at each position of the sheet at the time of reading can be calculated based on the converted position data, the inspection data is corrected with the amount of distortion, and the corrected inspection data and image data are compared and collated. As a result, the quality of the printed image can be determined with high accuracy.
[0049]
Next, a second embodiment of the image forming apparatus of the first invention will be described.
[0050]
In the second embodiment, as compared with the first embodiment, the coordinate scale recorded in advance on the recording medium is printed by a recording material containing an ultraviolet absorbing fluorescent material. The light source of the image reading unit emits light including an ultraviolet component having an intensity peak on the short wavelength side of the visible light region, and the image sensor for image reading is color-separated by a color filter and has different three primary colors. The difference is that the light receiving element receives light, but the rest is the same, so only the difference will be described.
[0051]
FIG. 7 is a diagram illustrating the spectral irradiation characteristics of the light source provided in the image reading unit according to the second embodiment.
[0052]
In FIG. 7, the vertical axis represents the relative intensity of light, and the horizontal axis represents the wavelength of light.
[0053]
The solid line in the figure represents the spectral irradiation characteristics of the light source provided in the image reading unit of the image forming apparatus of the present embodiment.
[0054]
This light source is a fluorescent lamp and contains a relatively large amount of ultraviolet light components, and mainly emits blue light. Therefore, the material that forms the coordinate scale portion irradiated with this light absorbs the energy of the ultraviolet light components. When excited, it emits fluorescence.
[0055]
FIG. 8 is a diagram illustrating an example of a recording medium on which a coordinate scale is printed in advance, which is used in the second embodiment.
[0056]
The recording medium shown in FIG. 8 is, for example, a white printing paper, and at least the entire printed image forming area on one side uses a fluorescent material-containing ink that absorbs an ultraviolet component and emits visible light, and has a line width. For example, a 500-micron grid scale 86 is printed with high accuracy.
[0057]
Here, the coordinate scale is not limited to a grid scale, and can be arbitrarily selected from an orthogonal coordinate scale, an oblique coordinate scale, a polar coordinate scale, and the like.
[0058]
The grid scale 86 recorded using this fluorescent material-containing ink absorbs the ultraviolet component of the light emitted from the light source of the image reading section and emits yellow fluorescence.
[0059]
This grid scale is described here so as to be visible for convenience, but when it is not irradiated with ultraviolet rays, it is actually almost colorless and transparent.
[0060]
FIG. 9 is a diagram illustrating a sensor provided in the image reading unit of the present embodiment.
[0061]
The sensor shown in FIG. 9 is formed of three parallel pixel rows each having a light receiving portion of 7500 pixels, and the light receiving surface of each pixel row is covered with blue, green, and red on-chip color filters. This is a line CCD color linear image sensor.
[0062]
The first pixel row 90 covered with the blue on-chip color filter is sensitive to blue color, and the second pixel row 91 covered with the green on-chip color filter is sensitive to green color. And the third pixel row 92 covered with the red on-chip color filter has sensitivity to the red color.
[0063]
FIG. 10 is a diagram showing the spectral sensitivity characteristics of the RGB 3-line CCD color linear image sensor.
[0064]
In FIG. 10, the vertical axis represents the specific sensitivity of the RGB 3-line CCD color linear image sensor, and the horizontal axis represents the wavelength (nm).
[0065]
A curve represented by a solid line or a dotted line in the figure represents the spectral sensitivity characteristic of each pixel column of the RGB 3-line CCD color linear image sensor.
[0066]
The spectral characteristic 90a of the first pixel row 90 covered with the blue on-chip color filter has a peak in the vicinity of about 450 nm and a half-value wavelength width of about 80 nm.
[0067]
In addition, the spectral characteristic 91a of the second pixel column in which the green on-chip color filter is formed has a peak in the vicinity of about 530 nm and a half-value wavelength width of about 70 nm.
[0068]
Further, the spectral characteristic 92a of the third pixel row in which the red on-chip color filter is formed has a peak in the vicinity of about 620 nm, the half-value wavelength width on the short wavelength side is about 600 nm, and the long wavelength side is gradually reduced. It has characteristics.
[0069]
When irradiated with blue light having a peak wavelength of 415 nm and containing an ultraviolet component from a fluorescent lamp of an image reading device, a printed image portion which is a portion recorded with a material containing carbon black is a blue on-chip color filter. A black image is recognized by the covered first pixel row. On the other hand, the yellow light from the grid graduation that absorbs the ultraviolet component and emits fluorescence is emitted from the second pixel column or the third pixel column covered with the green or red on-chip color filter. Either or both are recognized as white images.
[0070]
At this time, the print image portion received by the first pixel row outputs a negative signal, and the grid scale portion received by the second or third pixel row outputs a positive signal. The color linear image sensor can easily separate the signal from the print image portion and the signal from the grid scale portion and convert them into inspection data and position data, respectively.
[0071]
Since the distortion amount at each position of the paper at the time of reading can be calculated from the position data thus converted, the inspection data is corrected based on the distortion amount, and the corrected inspection data and the image data are compared and collated. By doing so, it is possible to dramatically improve the pass / fail judgment accuracy of the printed image.
[0072]
Next, a first embodiment of the second invention will be described.
[0073]
FIG. 11 is a schematic configuration diagram showing the image forming apparatus according to the first embodiment of the second invention.
[0074]
This embodiment is different from the first embodiment of the first invention in that the coordinate scale is simultaneously recorded on the recording medium when the print image is formed by the image forming apparatus, but the other points are common. Therefore, the same components as those of the first embodiment of the first invention shown in FIG.
[0075]
The image forming apparatus shown in FIG. 11 has an image forming unit 50 that forms a print image on a sheet, a paper feed / conveying unit 51 that supplies and conveys the sheet, and determines whether the print image is good and the sheet that has been printed. A finishing processing unit 52 that classifies a good print image for each page, a print image creation unit 53 that performs image processing or pulse modulation on image data, and a print image printed on paper and a coordinate scale are read. Is converted into inspection data and position data, corrected inspection data is corrected with position data, corrected inspection data is obtained, and compared with the image data and read to determine whether the printed image matches the original image Based on the determination results of the determination unit 54 and the reading determination unit 54, paper on which defective printing has been performed is excluded, or reprinting is instructed to the image forming unit 50. And a printer controller 55 for that.
[0076]
Here, the reading determination unit 54 compares and collates with the image data after obtaining the corrected inspection data obtained by correcting the inspection data, but directly compares and collates the inspection data with the image data in consideration of the positional deviation amount. You can also
[0077]
The print image creating unit 53 performs image processing on the image data raster-converted from the original image created by a personal computer or the like, or the image data read from the original image by the scanner, and binarizes and pulse-modulated the signal. It is generated and transmitted to the laser exposure device 56 of the image forming unit 50. The print image creation unit 53 also includes a memory 94 that stores coordinate scale data to be recorded in the image area of the paper according to the size of the paper, and the memory is based on the print size information in the image data. The coordinate scale data stored in 94 is subjected to image processing in the same manner as the image data to generate a pulse-modulated signal, which is transmitted to the laser exposure device 56 of the image forming unit 50.
[0078]
The image forming unit 50 includes a photosensitive drum 57 on which a toner image is formed and a transfer drum 60 for transferring the toner image. A charger 59 uniformly charges the photosensitive drum 57, and a laser exposure device 56 The photosensitive drum 57 is irradiated with laser light pulse-modulated based on the signal generated by the print image creation unit 53 to form an electrostatic latent image. The developing devices 58a and 58b are formed on the photosensitive drum 57. The electrostatic latent image is developed with toner to form a toner image on the surface of the photosensitive drum 57. The toner image formed on the surface of the photosensitive drum 57 is electrostatically transferred to the transfer drum 60 and then transferred onto the paper 61 conveyed from the paper feeding / conveying section 51 to the printing position 60. The fixing device 62 The transferred toner image on the paper 61 is fixed by heating and pressing to form a printed image. The paper on which the print image is formed is transported to the print image reading position 63 by the paper feed transport unit 51.
[0079]
In the present embodiment, there are a first developing device 58a and a second developing device 58b. Since the second developing device 58b includes a developer containing an infrared absorbing material, in the first process. The print image information generated by the print image creation unit 53 is developed by the first developing device 58a provided with a normal black developer. Next, based on the signal corresponding to the coordinate scale generated by the print image creation unit 53 in the second process, the electrostatic latent image formed by irradiating the laser beam from the laser exposure device 56 is the second The toner image corresponding to the coordinate scale is formed on the surface of the photosensitive drum 57 by being developed with the developer containing the infrared absorbing material of the developing device 58b, and the toner image corresponding to the coordinate scale is also transferred to the transfer drum 60. After that, since the image is transferred and fixed on the paper, the coordinate scale is recorded on the paper together with the print image.
[0080]
In this way, the coordinate scale on the paper is written by the same exposure optical system as the print image, and is simultaneously transferred and printed on the paper, for example, the formation process of the electrostatic latent image by the laser exposure device of the image forming unit, Even if an image shift or distortion occurs in the transfer process of the toner image in the transfer device, the coordinate scale also has a shift or distortion. Therefore, when calculating the amount of distortion of the paper based on the coordinate scale, not only the amount of distortion at the time of reading but also the deviation and distortion generated in the electrostatic latent image formation process and the toner image transfer process in the transfer device are included. In this state, the distortion amount is calculated, and when the inspection data read from the print image is corrected, the deviation and distortion are also corrected at the same time, so that more accurate collation is possible.
[0081]
Although the present embodiment has been described with reference to an electrophotographic recording type image forming apparatus, the image forming apparatus is not limited to an electrophotographic recording type, and may be a thermal recording type image forming apparatus, and ink may be used. It may be an image forming apparatus to be used or a printing apparatus. The image forming apparatus may be a printer or a copier.
[0082]
FIG. 12 is a diagram illustrating an example of a recording medium on which only a coordinate scale is recorded without forming a print image in the image forming apparatus of the present embodiment.
[0083]
A grid scale 86 shown in FIG. 12 forms an electrostatic latent image by exposing the surface of the photosensitive drum with an exposure device based on grid scale data having a line width of 500 microns stored in the memory of the print image creation unit. A toner image is formed by developing with an absorbent material-containing developer, and the toner image on the square scale is transferred and fixed on a recording medium to form the entire print image forming region.
[0084]
Here, only the coordinate scale 86 is recorded without forming a print image. However, a toner image based on the image data is formed on the same photosensitive drum, and is transferred onto the recording medium onto which the grid scale 86 is transferred. By doing so, a print image can be formed on the recording medium.
[0085]
Here, the grid scale is described so as to be visible for the sake of convenience, but the grid scale 86 is usually made difficult to visually recognize because it is formed of a developer containing an infrared absorbing material. The coordinate scale is not limited to a grid scale, and can be arbitrarily selected from an orthogonal coordinate scale, an oblique coordinate scale, a polar coordinate scale, and the like.
[0086]
Next, a second embodiment of the image forming apparatus of the second invention will be described.
[0087]
The second embodiment is different from the first embodiment in that the coordinate scale recorded simultaneously with the print image on the recording medium is developed with a developer containing an ultraviolet absorber, but otherwise. Common. Further, the characteristics of the coordinate scale developed with the developer containing the ultraviolet absorber, the principle of separately reading the inspection data and the position data by the image reading unit, etc. are described in the second embodiment of the first invention. Since it is the same as that described, the drawings and description are omitted here.
[0088]
This embodiment also has the same effect as described in the first embodiment and the second embodiment of the first invention.
[0089]
【The invention's effect】
As described above, according to the image forming apparatus of the present invention, since coordinate scales that are hardly visible to the naked eye are printed in all the image forming areas of the recording medium, the quality of the printed image formed on the recording medium is good. When determining the accuracy of the print image, it is possible to accurately grasp the distortion amount of the recording medium from the coordinate scale, and to compare and collate after correcting the read data. it can.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a first embodiment of an image forming apparatus according to a first invention.
FIG. 2 is a diagram illustrating functions of the image forming apparatus according to the first embodiment.
FIG. 3 is a diagram showing an example of a recording medium on which coordinate scales are printed in advance used in the first embodiment.
FIG. 4 is a diagram showing spectral reflectance characteristics of an infrared absorbing material-containing recording material used for recording a grid memory in the first embodiment and a color material containing carbon black used for recording a print image. .
FIG. 5 is a diagram illustrating spectral sensitivity characteristics of a CCD linear image sensor used as a sensor of an image reading unit.
FIG. 6 shows the signal levels of position data and inspection data obtained by irradiating light from a LED having a peak wavelength at 880 nm onto the paper used for printing in the present embodiment, and receiving and converting the reflected light by the CCD linear image sensor. FIG.
FIG. 7 is a diagram illustrating spectral irradiation characteristics of a light source provided in an image reading unit according to the second embodiment.
FIG. 8 is a diagram showing an example of a recording medium on which coordinate scales are printed in advance used in the second embodiment.
FIG. 9 is a diagram illustrating a sensor provided in an image reading unit according to a second embodiment.
FIG. 10 is a diagram showing spectral sensitivity characteristics of a CCD color linear image sensor.
FIG. 11 is a schematic configuration diagram showing an image forming apparatus according to the first embodiment of the second invention.
FIG. 12 is a diagram illustrating an example of a recording medium on which only a coordinate scale is recorded without forming a print image in the image forming apparatus according to the first embodiment.
[Explanation of symbols]
50 Image forming unit
51 Paper feed section
52 Finishing processing part
53 Print Image Creation Department
54 Reading determination unit
55 Printer Controller
56 Laser exposure equipment
57 Photosensitive drum
58a First developing device
58b Second developing device
59 Charger
60 Transfer drum
61 paper
62 Fixing device
63 Image reading position
64 paper tray
65 Double-sided tray
66 Paper transport roller
67 Paper transport belt
68 Purge tray
69 Scanner section
70 Image data
71, 81 frame memory
73,83 Pre-processing unit
74 Original image memory
80 Position data and inspection data
84 Print image memory
85 Inspection Department
86 grid scale
87 Bottom
90 first pixel column
90a Spectral characteristics of the first pixel column
91 Second pixel column
91a Spectral characteristics of second pixel column
92 Third pixel column
92a Spectral characteristics of the third pixel column
94 memory

Claims (4)

Image formation that records a print image on a recording medium based on image data representing the original image with a recording material that has a substantially constant reflectivity from the visible region to the near-infrared region and a lower reflectivity than an infrared absorber. In the device
The recording medium, on advance the recording medium, wherein in all regions print image is formed, there is the coordinate scale is formed in the recording material containing the infrared absorbing material,
With irradiating the recording medium the light is the print image from the light source emitting light of wavelength was recorded include an infrared region, the intensity of the reflected light from the coordinate scale for light of the reflected light from the printed image Due to the difference in intensity, the reflected light from the coordinate scale is extracted and converted into position data, and the reflected light from the print image is converted into inspection data, whereby the inspection data and the position data are extracted from the recording medium. Image reading means for reading the image separately from each other;
A distortion calculating means for calculating the distortion for each region on the recording medium based on the position data read by the image reading means,
By matching taking into account the distortion determined by the distortion calculating means and the obtained the test data the image data by the image reading means, determines whether the printed image coincides with the image data An image forming apparatus comprising: a determination unit that performs the determination. In an image forming apparatus for recording a print image on a recording medium based on image data representing an original image,
Onto the recording medium, the print image, and records in the recording material of a low reflectance than substantially constant and infrared absorber reflectivity up to the near infrared region from the visible region, on the recording medium, A recording unit that records a coordinate scale on a recording material including the infrared absorbing material in all areas where the print image is formed ;
With irradiating the recording medium the light is the print image from the light source emitting light of wavelength was recorded include an infrared region, the intensity of the reflected light from the coordinate scale for light of the reflected light from the printed image Due to the difference in intensity, the reflected light from the coordinate scale is extracted and converted into position data, and the reflected light from the print image is converted into inspection data, whereby the inspection data and the position data are extracted from the recording medium. Image reading means for reading the image separately from each other;
A distortion calculating means for calculating the distortion for each region on the recording medium based on the position data read by the image reading means,
By matching taking into account the distortion determined by the distortion calculating means and the obtained the test data the image data by the image reading means, determines whether the printed image coincides with the image data An image forming apparatus comprising: a determination unit that performs the determination. In an image forming apparatus for recording a print image with a recording material containing carbon black on a recording medium based on image data representing an original image,
The recording medium, on advance the recording medium, to all areas in which the print image is formed, which coordinates the scale has been recorded by the recording material by absorbing ultraviolet containing a fluorescent material that emits fluorescence of a predetermined color Because
A sensor sensitivity to the three primary colors is provided with a different light receiving elements, respectively, said light light from a light source that emits light having a wavelength is back is irradiated on the recording medium in which the printed image is recorded containing the ultraviolet region Light received by the sensor, detected by the combination pattern of the three primary colors representing the color of the received light, and reflected by the recording material containing the combination pattern corresponding to the light of the predetermined color and the carbon black The light received from the coordinate scale is converted into position data, and the light received from the print image is converted into inspection data, thereby detecting the inspection data from the recording medium. And image reading means for reading the position data separately from each other;
A distortion calculating means for calculating the distortion for each region on the recording medium based on the position data read by the image reading means,
By matching taking into account the distortion determined by the distortion calculating means and the obtained the test data the image data by the image reading means, determines whether the printed image coincides with the image data An image forming apparatus comprising: a determination unit that performs the determination. In an image forming apparatus for recording a print image on a recording medium based on image data representing an original image,
Given onto the recording medium, the print image, and records in the recording material containing carbon black, wherein on the recording medium, to all areas in which the printed image is formed, the coordinates scale, which absorb ultraviolet rays A recording unit for recording with a recording material including a fluorescent material that emits color fluorescence ;
A sensor sensitivity to the three primary colors is provided with a different light receiving elements, respectively, said light light from a light source that emits light having a wavelength is back is irradiated on the recording medium in which the printed image is recorded containing the ultraviolet region Light received by the sensor, detected by the combination pattern of the three primary colors representing the color of the received light, and reflected by the recording material containing the combination pattern corresponding to the light of the predetermined color and the carbon black The light received from the coordinate scale is converted into position data, and the light received from the print image is converted into inspection data, thereby detecting the inspection data from the recording medium. And image reading means for reading the position data separately from each other;
A distortion calculating means for calculating the distortion for each region on the recording medium based on the position data read by the image reading means,
By matching taking into account the distortion determined by the distortion calculating means and the obtained the test data the image data by the image reading means, determines whether the printed image coincides with the image data An image forming apparatus comprising: a determination unit that performs the determination.

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