JP4397851B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus, and more particularly to a technique for performing high-precision reading at a low cost.

  A conventional scanner electronically performs main scanning with a light receiving unit including a line sensor, and at the same time performs sub scanning by relative movement between the light receiving unit and a document to be read. In the sub-scanning direction, a feeding operation with small speed variation is required.

  However, in the conventional scanner as described above, it is necessary to control a high-precision motor by using a complicated drive circuit in order to reduce the speed variation, and thus there is a problem that the cost becomes high. .

  In order to solve such problems, the scanner disclosed in Patent Document 1 arranges a reference image in which marks are arranged at equal intervals in the sub-scanning direction, and reads the reference image together with a document. Then, the distortion of the read image based on the speed variation is corrected by using the interval between the marks in the obtained read image.

JP 2001-203859 A

  In the scanner disclosed in Patent Document 1, a document and a reference image are arranged side by side for reading. Therefore, a frame such as a frame is provided around the original and it is physically difficult to arrange it side by side with the reference image, or when the original is thick and the original and the reference image are within the depth of field of the light receiving unit. In the absence of the document, there is a problem in that the original and the reference image cannot be simultaneously read by the light receiving unit.

  The present invention has been made to solve the above-described problems, and provides an image reading apparatus that can perform high-precision reading at a low cost regardless of the shape of a document without arranging a reference image. Objective.

Image reading apparatus according to the present invention, a linear reading means having a line sensor in which a plurality of read elements are arranged in a row along the main scanning direction for reading an original image from a document, the linear reading means integral reduction are marked light source for irradiating a light mark on the document, moving the relative position of the linear reading means and the mark light source with respect to the document along the vertical sub-scanning direction in the main scanning direction The linear reading is performed by projecting the light onto the original by partially interrupting or changing the path of the light while being operated integrally with the original, and being interposed between the moving means for making the original and the mark light source. the image obtained by the means, and the correction image adding means for adding a correction image composed of a plurality of marks arranged in a row along the sub-scanning direction, the linear reading Ri using the correcting image distortion based on the variation of the moving speed of the moving means in the original image read by the means and a correcting means for correcting.

Image reading apparatus according to the present invention, a linear reading means having a line sensor in which a plurality of read elements are arranged in a row along the main scanning direction for reading an original image from an original, said for the original linear reading means moving means for the relative position movement in the main scanning direction along the vertical sub-scanning direction, the mark light source for irradiating a light mark on the document, interposed between the light source for the original mark, the document The image is obtained by the linear reading means in a row along the sub-scanning direction by partially blocking or changing the light path and projecting the light onto the document. and correcting the image adding unit that adds a correction image composed of a plurality of marks aligned, the moving speed of the moving means in the original image read by the linear reading means Distortion based on variability and a correcting means for correcting using the correction image. Therefore, even when a frame such as a frame is provided around the document or when the document is thick, the document and the correction image can be read side by side. Therefore, high-precision reading can be performed at low cost regardless of the shape of the document.

  The scanner according to the present invention is characterized in that a correction image is added to a captured image without arranging a reference image. Embodiments and modifications thereof will be described below with reference to the drawings.

<Embodiment 1>
FIG. 1 is a perspective view schematically showing a configuration of a scanner 100 according to the first embodiment.

  A scanner 100 shown in FIG. 1 includes a document support table 10, a light receiving unit 20, a mark light source 30, a slit unit 40, an actuator 50, and a computer 60.

  The document support table 10 is for placing and supporting a document 300 made of paper or the like on which an original image is printed as a subject.

  The light receiving unit 20 receives light received by a line sensor (not shown) in which a plurality of light receiving elements (not shown) as reading elements for reading an original image from the original 300 are arranged in a line along the main scanning direction a. And a lens (not shown) that collects light on the line sensor, and extends in the main scanning direction a. That is, the light receiving unit 20 functions as a linear reading unit according to the present invention.

  The mark light source 30 is composed of a laser light source (not shown) and a lens (not shown), and irradiates parallel light, and is integrated with the light receiving unit 20.

  The slit portion 40 extends in the sub-scanning direction b perpendicular to the main scanning direction a, and is integrated with the document support base 10 so as to be interposed between the document 300 and the mark light source 30. The slit portion 40 has slit holes 41 in which a plurality are arranged in a line at equal intervals along the sub-scanning direction b. These slit holes 41 are vertically long rectangles and have the same length and width, and the length direction is along the main scanning direction a and the width direction is along the sub-scanning direction b. The slit portion 40 partially blocks the light path (optical path) by transmitting light through the slit hole 41 and blocking light at portions other than the slit hole 41.

  The actuator 50 includes a motor 51 formed of, for example, a stepping motor, and a uniaxial moving stage 52 that is driven by the motor 51 and moves the light receiving unit 20 along the sub-scanning direction b. That is, the actuator 50 functions as a moving unit according to the present invention.

  The computer 60 includes a storage unit 61 including a main memory that stores an image captured from the line sensor of the light receiving unit 20 via the wiring 71, and a processing unit 62 including a CPU that corrects the image stored in the storage unit 61. Including. The processing unit 62 controls the actuator 50 via the wiring 72.

  The parallel light emitted from the mark light source 30 is projected onto the document 300 through a plurality of slit holes 41 arranged in a line at equal intervals on the slit portion 40, but is integrated with the mark light source 30. A mark of the same type as that of the slit hole 41 is formed in a region immediately below the light receiving unit 20. In FIG. 1, this area is shown as a mark 321. That is, the mark 321 has parallel light from the mark light source 30 on the vicinity of an intersection line (shown by a dotted line in FIG. 1) between the plane passing through the center line of the light receiving unit 20 and perpendicular to the document 300 and the document 300. It is displayed in the area that is transmitted through the slit hole 41 and projected.

  The light receiving unit 20 is moved along the sub-scanning direction b by the actuator 50 and electronically receives light using a light-receiving element along the main scanning direction a, thereby reading the document 300 with the mark 321 added thereto. Image data of the additional image is generated. Since the mark light source 30 is integrated with the light receiving unit 20, the mark 321 also moves along the sub-scanning direction b as the light receiving unit 20 moves. Accordingly, an image is obtained on the original 300 in which correction images made up of a plurality of marks 321 arranged in a line along the sub-scanning direction b at equal intervals are added to the original image. That is, the slit portion 40 functions as a correction image adding unit according to the present invention.

  In the present embodiment, as shown in FIG. 1, the mark light source 30 and the slit portion 40 are arranged on the surface side of the document 300 in the same manner as the light receiving unit 20. Done. The document 300 is fixed to the document support 10 integrated with the slit portion 40 and does not move.

  Image data of the mark-added image generated in the light receiving unit 20 is sent to the computer 60 via the wiring 71 and stored in the storage unit 61. 2A shows an original image 310, and FIG. 2B shows a mark added image 330 including the original image 310 and the correction image 320. A mark added image 330 shown in FIG. 2B is obtained by adding a mark 321 along the sub-scanning direction b in the original image 310 shown in FIG. 61 is an image stored in 61.

  The image data of the mark-added image 330 stored in the storage unit 61 is corrected by the processing unit 62 using an existing correction method disclosed in Patent Document 1 or the like. That is, on the original 300, the plurality of marks 321 are projected with equal lengths and widths arranged at equal intervals, so that the actuator 50 moves the light receiving unit 20 along the sub-scanning direction b. If there is no speed variation at all, even in the image data stored in the storage unit 61, the marks 321 have the same length and width and are arranged at equal intervals. Accordingly, the processing unit 62 extracts variations (distortions) in the width and interval of the mark 321 from the image data stored in the storage unit 61, thereby moving the light receiving unit 20 along the sub-scanning direction b by the actuator 50. Speed variation can be obtained. Then, the processing unit 62 performs correction processing by applying expansion / contraction to the image data so as to eliminate this speed variation (that is, to eliminate variations in the width and interval of the extracted mark 321). In other words, the processing unit 62 functions as a correction unit according to the present invention, and corrects distortion of image data based on speed variation of the actuator 50 using the correction image 320. Therefore, high-precision reading can be performed at low cost without using a complicated drive circuit or high-precision motor.

  The correction image 320 included in the image data of the mark added image 330 is deleted after the correction process is completed.

  As described above, the scanner 100 according to the present embodiment adds the correction image 320 to the document 300 using the slit portion 40 in which the plurality of slit holes 41 are arranged, and uses the correction image 320 for the actuator. The speed variation due to 50 is corrected. Therefore, even when a frame such as a frame is provided around the original 300 or when the original 300 is thick, the original 300 and the correction image 320 can be read in a line. Therefore, high-precision reading can be performed at low cost regardless of the shape of the original 300.

<Modification 1>
In FIG. 1 of the first embodiment, the mark light source 30 and the slit portion 40 are installed on the surface side of the document 300, so that light is received by reflection on the document 300. However, when the document 300 is transparent or translucent, the mark light source 30 and the slit portion 40 may be installed on the back side of the document 300.

  FIG. 3 is a perspective view schematically showing the configuration of the scanner when the mark light source 30 and the slit portion 40 are installed on the back side of the document 300. In FIG. 3, light reception is performed by transmission through the original 300 instead of reflection at the original 300.

  In the configuration of FIG. 3, the mark light source 30 and the slit portion 40 are installed on the opposite side of the light receiving portion 20 with the document 300 interposed therebetween. Therefore, light emitted from the mark light source 30 is directly received by the light receiving unit 20 as compared with the configuration of FIG. In order to be detected, the contrast of the mark 321 can be increased to facilitate the recognition of the correction image 320, and the degree of freedom in installation can be increased.

  In addition, transmitted light is used instead of reflected light, and parallel light emitted from the mark light source 30 can be perpendicularly incident on the original 300 so that the amount of light can be concentrated in a small area. , Can increase the illuminance. Therefore, the contrast of the correction image 320 can be increased and the correction image 320 can be easily recognized.

<Modification 2>
In FIG. 1 of the first embodiment, the light receiving unit 20 is moved using an actuator 50. However, the document 50 may be moved instead of the light receiving unit 20 by using the actuator 50. Alternatively, the relative positions of the light receiving unit 20 and the document 300 may be moved by using the actuator 50 to move at different speeds.

<Modification 3>
In FIG. 1 of the first embodiment, a slit portion 40 in which a plurality of slit holes 41 are arranged in a line at equal intervals is used as a correction image adding means for adding a correction image 320 to a document 300. . However, as a correction image adding means, instead of the slit portion 40 in which a plurality of slit holes 41 are arranged in one row at equal intervals, a mirror portion in which a plurality of mirrors are arranged in one row at equal intervals is used. It may be used.

  FIG. 4 is a perspective view schematically showing a configuration of a mirror unit 80 in which a plurality of mirrors 81 made of triangular prisms are arranged in a line at equal intervals. As shown in FIG. 3, the mirror 81 made of a triangular prism reflects light on the slope. FIG. 5 is a cross-sectional view schematically showing the positional relationship among the mirror unit 80, the mark light source 30, and the document 300. 4 to 5, the parallel light emitted from the mark light source 30 is selectively reflected only by the mirror 81 and projected onto the document 300 by the mirror unit 80. By changing the optical path in this manner, the marks 321 corresponding to the mirror 81 can be displayed at equal intervals on the original 300.

<Modification 4>
In FIG. 4 of the third modification, the optical path is changed using reflection by the mirror 81, but the optical path may be changed using refraction by a prism instead of reflection by the mirror 81.

<Modification 5>
In FIG. 1 of the first embodiment, the optical path is partially blocked using a slit portion 40 in which a plurality of slit holes 41 having the same length and width are arranged at equal intervals. However, the optical path may be blocked using other means. For example, you may use the slit part provided with the slit hole from which a width | variety or a space | interval changes regularly with a position. Alternatively, a filter whose light transmission characteristics regularly change depending on the position may be used. As such a change in the light transmission characteristic, any regular change that can be detected by the light receiving unit 20 may be used. For example, the luminance or color may change sinusoidally, the luminance may monotonously increase or decrease monotonously, the luminance or color may change continuously, and the width Alternatively, the interval may change continuously.

<Modification 6>
In FIG. 1 of the first embodiment, the light receiving unit 20 is moved by a one-axis moving stage 52 driven by a motor 51 formed of a stepping motor or the like. However, the light receiving unit 20 may be moved by a linear stage instead of the uniaxial moving stage 52, or may be manually moved manually.

<Modification 7>
In FIG. 1 of the first embodiment, the actuator 50 includes a motor 51 and a uniaxial moving stage 52 driven by the motor 51. However, when the document 300 is made of a film, cloth, or the like, the actuator may be configured to include two drums that wind and rotate the document 300.

  The actuator shown in the perspective view of FIG. 6 includes drums 91a and 91b having rotation axes parallel to each other, a motor 92 for rotating the drum 91a, and a chain 93 for transmitting the rotational force of the drum 91a to the drum 91b. Composed. The chain 93 is provided with a plurality of slit holes 41 ′ for partially transmitting light. That is, the mark 321 (not shown in FIG. 6) is displayed on the original 300 by irradiating parallel light through the slit hole 41 '.

  In FIG. 6, a document 300 made of a film, cloth, or the like previously wound around a drum 91 b is wound around the drum 91 a by rotating a motor 92. Accordingly, the relative position between the light receiving unit 20 (not shown in FIG. 6) and the document 300 can be moved along the sub-scanning direction b. The slit hole 41 ′ (that is, the mark 321) on the chain 93 and the document 300 move at a constant relative speed.

  As described above, the scanner can be miniaturized by using a drum as the moving means instead of the stage and using a chain as the correction image adding means instead of the slit portion.

<Modification 8>
In FIG. 6 of the modified example 7, a document 300 made of film or cloth is wound around the drums 91a and 91b. When the document 300 is made of paper, the actuator uses two drums that rotate with the document 300 interposed therebetween. It may be configured to include.

  The actuator shown in the perspective view of FIG. 7 includes a drum 91c and an auxiliary drum 94 having rotation axes parallel to each other, and a motor 92 for rotating the drum 91c. The drum 91c is integrated with an annular slit portion 40 'provided with a plurality of slits 41' for partially transmitting light. The annular slit portion 40 'has a larger diameter than the drum 91c and the same rotation axis as the drum 91c. In other words, the mark 321 is displayed on the original 300 when parallel light is irradiated through the slit hole 41 ′ from the mark light source 30 disposed outside the slit portion 40 ′.

  In FIG. 7, a document 300 made of paper is sandwiched therebetween by being pressed against the drum 91 c by the auxiliary drum 94. Therefore, by rotating the drum 91c using the motor 92, the relative position between the light receiving unit 20 (not shown in FIG. 7) and the document 300 can be moved. Since the annular slit portion 40 ′ and the drum 91c are integrated so as to have the same rotation axis, the relative position between the slit hole 41 ′ (that is, the mark 321) and the document 300 is a constant relative speed. Moving.

<Modification 9>
In FIG. 7 of the modified example 8, the drum 91c is integrated with an annular slit portion 40 ′ provided with a plurality of slits 41 ′ for partially transmitting light. The mark 321 is displayed on the document 300 by irradiating parallel light from the mark light source 30 installed outside the slit portion 40 through the slit hole 41 ′.

  However, when the document 300 is transparent or semi-transparent, parallel light may be irradiated from a mark light source installed inside a hollow drum provided with a plurality of slit holes 41 ′.

  The actuator shown in the perspective view of FIG. 8 uses a hollow drum 91d provided with a plurality of slit holes 41 ′ instead of the drum 91c and the slit portion 40 ′ integrated with the drum 91c in FIG. It was. In FIG. 8, the mark 321 is displayed on the original 300 by irradiating parallel light from the mark light source 30 installed inside the drum 91 d through the slit hole 41 ′. Since the document 300 is transparent or translucent, the mark 321 displayed on the document 300 can be detected by the light receiving unit 20 (not shown in FIG. 8) installed outside the drum 91d.

  In this way, the scanner can be further miniaturized by installing the mark light source 30 inside the drum instead of outside the drum.

<Modification 10>
In FIG. 1 of the first embodiment, the mark 321 is displayed by using the light emitted from the mark light source 30. However, the mark 321 may be displayed using other means instead of light. As such means, any means may be used as long as the path can be changed by means such as the slit section 40 and the reading can be performed by means such as the light receiving section 20.

  As such means, light may be irradiated with other electromagnetic waves (X-rays or the like) that further expands the wavelength range, or particles such as ink, electrons, neutrons, molecules, atoms, ions, etc. You may irradiate from a particle irradiation source. That is, the particle irradiation source functions as means for displaying the mark 321 instead of the mark light source 30 as the mark particle irradiation source.

<Modification 11>
In FIG. 1 of the first embodiment, a document 300 made of paper or the like on which the original image 310 is printed is used. However, the document 300 may be another material as long as the original image 310 is displayed.

  Examples of such materials include metals, materials such as glass, resin, film, cloth, and concrete. Alternatively, the original image 310 may be drawn directly on the ground surface.

2 is a perspective view illustrating a configuration of a scanner according to Embodiment 1. FIG. FIG. 3 is a top view showing an original image and a mark added image according to the first embodiment. FIG. 10 is a perspective view illustrating a configuration of a scanner according to Modification Example 1. It is a perspective view which shows the structure of the mirror part which concerns on the modification 3. FIG. 10 is a cross-sectional view schematically showing a positional relationship among a mirror portion, a mark light source, and a document according to Modification 3. 10 is a perspective view showing a configuration of an actuator according to Modification 7. FIG. 10 is a perspective view illustrating a configuration of an actuator according to Modification Example 8. FIG. 10 is a perspective view showing a configuration of an actuator according to Modification 9. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Document support stand, 20 Light receiving part, 30 Mark light source, 40 Slit part, 41 Slit hole, 50 Actuator, 51, 92 Motor, 52 Single axis moving stage, 60 Computer, 61 Storage part, 62 Processing part, 71, 72 Wiring, 80 mirror section, 81 mirror, 91 drum, 93 chain, 94 auxiliary drum, 100 scanner, 300 original, 310 original image, 320 correction image, 321 mark, 330 mark added image.

Claims (5)

Linear reading means having a line sensor in which a plurality of reading elements for reading an original image from a document are arranged in a line along the main scanning direction;
A mark light source integrated with the linear reading means for irradiating the original with mark light;
Moving means for moving a relative position between the linear reading unit and the mark light source with respect to the document along a sub-scanning direction perpendicular to the main scanning direction;
Obtained by the linear reading means by interposing between the original and the light source for the mark and projecting the light onto the original while partially operating or blocking the light path while operating integrally with the original. Correction image adding means for adding a correction image composed of a plurality of marks arranged in a line along the sub-scanning direction to the image to be obtained ;
An image reading apparatus comprising: correction means for correcting distortion based on variation in moving speed of the moving means in the original image read by the linear reading means using the correction image. The image reading apparatus according to claim 1,
The image reading apparatus, wherein the linear reading unit, the mark light source, and the correction image adding unit are arranged on the front side of the document . The image reading apparatus according to claim 1 ,
The image reading apparatus, wherein the linear reading unit is disposed on the front side of the document, and the mark light source and the correction image adding unit are disposed on the back side of the document . An image reading apparatus according to any one of claims 1 to 3 ,
The image reading apparatus , wherein the moving means includes a stage for moving the linear reading means along the sub-scanning direction and a motor for driving the stage . An image reading apparatus according to any one of claims 1 to 3 ,
The moving means includes a drum for moving the document along the sub-scanning direction and a motor for rotating the drum. The correction image adding means is arranged in an annular shape and is integrated with the drum. A working image reading device.

Images