JP2000050014A - Image scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanner system having an optical system not to expand one part of a device near the center of an image reading part in the case of reading a slip image. SOLUTION: This image scanner scans the surface of a paper sheet 1 by rotating a rotary mirror 8 and moves the optical axis center of a lens 2 from the center of a slip reading range. In this case, a distance between a sensor 3 and the lens 2 is fixed and by vertically moving the lens 2 and sensor 3 so as to keep constant the total value of distances from the paper sheet 1 to the mirror 8 and from the mirror 8 to the lens 2, in the case of scan, the focusing control of images is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image scanner for optically reading an image on a form such as a form, such as an OCR process for a public money voucher, a deposit / withdrawal voucher, and the input of a graphic / line image in a banking business. The present invention relates to an image scanner that performs an image reading process on various types of paper for performing image reading.

[0002]

2. Description of the Related Art Generally, a one-dimensional image is used as an image scanner for inputting an image on a sheet, for example, an image for OCR processing of various slips and forms in a banking business, and a seal / portrait / sign on a sheet. An image (line) sensor for optically reading an image is fixed, and a sheet is conveyed on the image sensor to read an image (referred to as a sensor fixing method). A system that reads an image by moving a sensor (referred to as a flatbed scanner system)
Are the two main types.

In recent years, a method of reading an image using a camera having a two-dimensional image reading sensor (referred to as a two-dimensional sensor method) has been proposed as an image scanner. This two-dimensional sensor type scanner is difficult at present to read images with high definition enough to optically recognize characters on paper due to the small number of pixels of the two-dimensional sensor. Applied. As a method of improving this method, a head unit including a lens is disposed in front of a sheet, and a one-dimensional image reading head unit or a sensor is moved in a sub-scanning direction on a surface on which an image of the sheet is formed via a lens ( A main / sub scanning method is also conceivable.

The two-dimensional image sensor of the two-dimensional sensor type and the main-sub-scanning type can scan an image even in a job in which the thickness changes depending on the type of paper, which cannot be handled by the paper transport system, or when a plurality of papers are bound. Can also be read. It is possible to prevent the sheet surface to be read from becoming invisible to a sheet installer as in the flatbed scanner system. References that describe these image scanner technologies include, for example, Japanese Patent Application Laid-Open No. 5-153344.
Publication.

[0005]

The above-described image scanners of each type have a problem that the size of the apparatus is increased due to the method of transporting or placing paper. In addition, in the two-dimensional sensor type and the main / sub scanning type image scanners, in addition to the above-mentioned problem of the enlargement, the head unit may be obstructed when the paper is set because the reading head part protrudes in front of the paper surface. There was a problem in that it included dangers in terms of safety, such as falling into contact with the operator.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art, and to provide an image scanner which is small in size and has good safety and operability. Specifically, an object of the present invention is to improve a two-dimensional sensor type and a main-sub scanning type image scanner suitable for reading a form at a bank or the like, to improve operability when setting paper, and to improve the security. It is another object of the present invention to provide an image scanner capable of improving the shape of the office, in which the reading head projects over the front (upper) of the sheet surface, which obstructs the scene of an office.

[0007]

In order to achieve the above object, the present invention provides a mirror for reflecting an image on paper and a one-dimensional sensor for optically reading an image reflected by the mirror via a lens. An optical scanner comprising the lens and the sensor is separated from the center of an image reading range, and the image scanner scans and receives an image on a sheet by rotating the mirror. The first feature is that the lens and the sensor are moved with respect to the rotation axis of the mirror so that the distance from the lens to the paper surface is kept constant while the distance between the lens and the sensor is fixed.

The present invention further comprises a mirror for reflecting an image on a sheet of paper and a one-dimensional sensor for optically reading the image reflected by the mirror via a lens. In an image scanner that separates from the center of the reading range and scans and receives an image on a sheet by rotating the mirror, the distance between the rotation axis of the mirror and the sheet is configured to be variable, and the distance between the lens and the sensor is changed. The second feature is that the rotation axis of the mirror is moved relative to the lens such that the distance from the lens to the paper surface is kept constant while the lens and the sensor are fixed.

The present invention further comprises a mirror for reflecting an image on a sheet of paper and a one-dimensional sensor for optically reading the image reflected by the mirror via a lens. In an image scanner that separates from the center of the reading range, scans an image on a sheet by rotating the mirror, and receives an image, a sensor is attached to the lens with the distance between the rotation axis of the mirror and the sheet and the lens fixed. Third, it was configured to move
The feature of.

According to a fourth aspect of the present invention, in the image scanner having the above-described features, the angle of the mirror is controlled so that the rotation of the mirror scans the sheet surface at a constant speed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Prior to this, the principle of the present invention will be described. First, in the above-described conventional two-dimensional sensor type and main / sub-scanning type image scanners, a reading head unit is put in front of a paper (document or form) in principle in order to arrange a lens in front of a reading paper. It was the shape that came out.

A specific example of this will be described with reference to the main-sub scanning method shown in FIG. In the apparatus of this system, a lens 2 is disposed in front of a reading sheet 1 placed on a base 5 and a one-dimensional image reading sensor 3 is moved in a sub-scanning direction (direction of arrow A) on a surface on which an image of the sheet 1 is formed. The image is read equivalently to the two-dimensional sensor system by moving the lens 2 so that the lens 2 forms the image of the sheet 1 on the moving surface of the one-dimensional image reading sensor 3. This two-dimensional image reading sensor can use, for example, a one-dimensional image reading sensor. For example, considering that 5000 pixels are moved in the sub-scanning direction, 5000 pixels × 7500 scans = 3750.
Comparable to a two-dimensional image reading sensor with 10,000 pixels, it is suitable for reading images of much higher definition,
However, since the position can be adjusted while directly viewing the sheet 1, the operability is excellent.

However, the image scanner has a shape in which the reading section is protruded in front of the sheet 1 (the upper part in FIG. 3), so that it is difficult to perform the alignment of the sheet 1 and, in some cases, the head is placed on the head of the sheet installer 7. There was also a risk of contact.

In order to improve this, the present inventors dispose the reading head unit at a position where the installation of the sheet is not hindered, and provide a reading head having an optical system capable of optically scanning an image on the sheet even in this arrangement. Invented an image scanner that includes: As this optical system, the inventors arranged the reading head at a position separated from the sheet, in other words, shifted the optical axis center of the lens from the center of the image reading range,
Furthermore, in order to prevent image degradation and image size change (deformation) caused by a shift in focus caused by a change in the paper surface distance to the paper surface scanned by the scanner, the distance between the rotating mirror that scans the paper surface and the paper surface The invention has invented an image scanner provided with a moving mechanism for moving a light receiving sensor section including a lens in order to keep the constant. That is, according to the present invention, the distance between the mirror and the sheet (lens) is prevented in order to prevent the defocus from occurring due to the change in the distance between the mirror and the sheet caused by the rotation of the mirror rotating to scan the entire surface of the sheet. The present invention in which the light receiving sensor or the mirror is moved so that the forward distance) maintains a constant relationship has been invented.

<Embodiment 1> Hereinafter, an image scanner according to an embodiment of the present invention will be described step by step. FIG.
FIG. 1 is a diagram illustrating a basic configuration of an image scanner according to a first embodiment of the present invention. The scanner includes a sheet table 5 on which a sheet 1 to be scanned is mounted in a depth direction of the drawing, and a sheet table 5 arranged on a side surface of the sheet. And a scanner body 100 to be
The scanner main body 100 includes a sensor 3 for reading an image on a sheet 1, a lens 2 for condensing scanning light scanned from the sheet 1 on the sensor 3, and a scan for scanning the entire surface of the sheet 1 with the lens 2. A rotating mirror 8 that rotates to give light, a driving mechanism 6B for rotating the rotating mirror 8, and a driving mechanism 6A that drives these up and down while maintaining the distance between the lens 2 and the sensor 3 are included. Prepare.

The sensor 3 is, for example, a one-dimensional 5000-pixel reading sensor, and is equivalent to a 37.5-million-pixel two-dimensional image reading sensor by scanning 7,500 in the sub-scanning direction. The drive mechanism 6B rotates a mirror 8 so that the sensor 3 moves the scanning light from the sheet so that the entire surface of the sheet is scanned in the sub-scanning direction. This is for adjusting the distance to the mirror 8 by moving it up and down integrally while keeping the distance to the lens 2 constant.

In the image sensor according to the present embodiment, the lens 2 and the one-dimensional image reading sensor 3 are driven by a driving mechanism 6A.
With respect to the change in the optical path length in front of the lens (a ₁ + a ₂ : the distance from the lens 2 to the scan position on the sheet 1 via the mirror 8), the lens 2 and the lens 2 satisfy the following equation 1 which is the basic characteristic of the lens. The one-dimensional image reading sensor 3 is moved by the driving mechanism 6A. In FIG and wherein the focal length of the f lens 2, a ₁ is the distance from the mirror -8 to Sukiyan position on the sheet 1, the distance a ₂ from the mirror -8 to lens 2, thus (a ₁ + a ₂₎ the lens forward light path length, a ₃ is backward light path length of the lens 2 (the distance from the lens 2 to the sensor 3)
It is.

[0018]

(Equation 1)

That is, in the image scanner according to the present embodiment, the focal point f and the rear optical path length are changed in accordance with the change of the distance a ₁ due to the rotation of the rotary mirror 8 for performing scanning using the line sensor on the sheet 1. for a ₃ is fixed, the drive mechanism 6A so as to satisfy the condition of equation 1 is the distance a
_Operates to change ₂ . For example, in the state of FIG. 1, as the mirror 8 rotates clockwise and the distance a ₁ becomes shorter, the driving mechanism 6A changes the distance a _{2 so} as to satisfy the above-mentioned formula 1 (increase a ₂ ). .

With this configuration, the image scanner according to the present embodiment maintains the relationship of the above equation 1 according to the rotation of the mirror 8, thereby keeping the image received by the sensor 3 in focus and keeping the image of the paper 1 as it is. Light can be received as a normal image. When the driving mechanism 6A is not used, the sensor light-receiving image is defocused because the optical path length in front of the lens changes according to the scan, and the image of the sheet 1 changes to a trapezoid. Particularly, in the image scanner according to the present embodiment, the reading portion does not protrude in the front (upper part) of the sheet 1, so that it does not cause a mechanical obstacle when setting the sheet 1 and does not obstruct the field of view of the sheet installer.

<Embodiment 2> Next, the basic configuration of an image scanner according to a second embodiment of the present invention will be described with reference to FIG. The image scanner includes a sheet table 5 on which a sheet 1 to be scanned is mounted in the depth direction of the drawing, and a scanner main body 101 disposed on a side of the sheet. A sensor 3 for reading an image, a lens 2 for condensing the scanning light scanned from the sheet 1 on the sensor 3, and a sheet 1 for the lens 2
The apparatus includes a rotating mirror 8 that rotates to give scanning light that scans the entire surface, and a driving mechanism 6 that rotates and vertically moves the rotating mirror 8.

In the scanner according to the present embodiment, the positions of the lens 2 and the sensor 3 are fixed, and the rotating mirror 8 is moved not only for scanning but also in the vertical direction, and the driving mechanism is maintained so as to maintain the relationship of the above-described equation (1). Numeral 6 is for moving the mirror 8 up and down. That is, the present scanner, according to the distance a ₁ by the rotation of the rotating mirror 8 is changed, the order of focus f and the backward light path length a ₃ fixed, the drive mechanism 6 is a distance so as to satisfy the condition of Equation 1 It operates as changing the a _2. Mirror 8 is intended to vary the distance a ₂ as drive mechanism 6A in response to the shorter distance a ₁ is rotated in a clockwise direction satisfies Equation 1 in the state of FIG. 1, for example a (a ₂ Lengthen). According to the present embodiment, since the mirror 8 is moved up and down, the optical path length in front of the lens can be corrected approximately twice as much as the amount of movement of the mirror 8, and there is an advantage that the amount of movement of the mirror 8 can be reduced and the apparatus can be downsized. .

Third Embodiment Next, the basic structure of an image sensor according to a third embodiment of the present invention will be described with reference to FIG. The image scanner comprises a sheet table 5 on which a sheet 1 to be scanned is mounted in the depth direction of the drawing, and a scanner body 103 arranged on the side of the sheet 1. Sensor 3 for reading an image of the subject, a lens 2 for condensing the scanning light scanned from the sheet 1 on the sensor 3, and a sheet 1
A rotating mirror 8 that rotates to give scanning light that scans the entire surface, and a driving mechanism 6 that rotates the rotating mirror 8
B, and a drive mechanism 6A that moves the sensor 3 up and down to adjust the distance to the lens 2.

That is, the image scanner according to the present embodiment has a configuration in which the rotating mirror 8 and the lens 2 are fixed vertically and the sensor 3 is vertically movable with respect to the lens 2, as compared with the above-described embodiment. This method corrects the length a ₃ (distance between the lens and the sensor). When the scanner according to the present embodiment employs a reduction optical system, the optical path length (a ₁ + a ₂ ) in front of the lens can be made sufficiently larger than the optical path length a _{3 in the} rear of the lens, and the optical path length a in the short distance of the lens.
_By simply controlling 3, light can be received while maintaining the focus of the image received by the sensor 3.

This embodiment corrects the optical path length at the rear of the lens instead of the optical path length at the front of the lens. Since the correction amount is small, a piezoelectric element and a voice are used instead of the correction of a large moving amount by a motor or the like. A high-speed and small-sized driving element such as a coil can be used. However, this system is different from the systems of FIGS. 1 and 2 in which the optical path length (a ₁ + a ₂ ) in front of the lens is always corrected to a constant amount, and has a characteristic that the reduction ratio of the optical system changes according to the scanning position. . That is, the optical path length (a ₁ + a ₂ ) in front of the lens changes according to the scan position.
Has the characteristic that the reduction ratio changes.

[0026]

(Equation 2)

For this reason, the image read by the sensor 3 does not have a similar shape to the paper image, and causes a change in the shape represented by the equation (2). For example, the read image is read after being transformed into a trapezoid. Therefore, the image scanner according to the present embodiment needs to perform the inverse correction of Expression 2 on the read image data.

The above is the conceptual configuration of the image scanner according to the embodiment of the present invention. Next, specific mechanisms and the like of each embodiment will be described.

<Description of Mirror Up / Down and Rotation Mechanisms Corresponding to Second Embodiment> FIG. 5 shows an example of a mechanism for moving the mirror 8 applied to the image scanner according to the second embodiment in the up / down direction while rotating. . The mechanism includes a rotating mirror 8 rotatably supported by a mirror rotating drum 7,
A linear moving section 9 that holds the mirror rotating drum 7 and can move up and down along a linear moving rail 10; a tension mechanism 11B that applies an upward tension to the linear moving section 9; A drive mechanism 60 for applying a downward tension by a speed reducer and a winding mechanism via the
A tension mechanism 11A that engages one end of the wire A and applies a rotational force to the mirror rotating drum 7 in the clockwise direction in the figure;
And a driving mechanism 61 for engaging the other end of the mirror rotating drum 7 to apply a downward tension to the mirror rotating drum 7 by a speed reducer and a winding mechanism. Note that black circles in the drawings described in this embodiment and other embodiments indicate that a wire or the like is fixed to a fixed point such as a housing of the apparatus, and white circles indicate a fastening point of a wire to a moving member. ing.

In this mechanism, the driving mechanism 60 is provided with a tension mechanism 11B.
The rotating mechanism 8 supported by the linear moving unit 9 is moved up and down by winding and loosening the wire 12B against the tension of the wire 12B, and the driving mechanism 61 winds the wire 12A against the tension of the tension mechanism 11A. By performing the loosening operation, the rotating mirror 8 supported by the linear moving unit 9 is rotated via the rotating drum 7. This mechanism includes the drive mechanism 60
And 61, the mirror 8
Can be rotated and moved up and down to control the scan position on the paper surface and correct the optical path length (a ₁ + a ₂ ) in front of the lens. In particular, in this embodiment, by controlling the rotation and up and down of the mirror by separate mechanisms, it is possible to finely control the mirror vertical position according to the mirror rotation.

FIG. 6 is a diagram showing an improved example of the mechanism shown in FIG. 5, and shows a mechanism for rotating and vertically moving the mirror 8 by one driving mechanism. This mechanism includes a rotating mirror 8 rotatably supported by a cam mechanism 13 having a predetermined outer shape, a linear moving rail 10 holding the cam mechanism 8 and holding the cam mechanism 8.
A linear moving unit 9 that can move up and down, a tension mechanism 11B for applying an upward tension to the linear moving unit 9, and a downward tension applied to the moving unit 9 via a wire 12B by a speed reducer and a winding mechanism. Drive mechanism 62 for providing
There is provided a tension mechanism 11C which engages with one end of 2A and applies a rotational force to the cam mechanism 13 in a counterclockwise direction in the figure.

In this mechanism, the driving mechanism 62 is provided with a tension mechanism 11B.
The rotating mirror 8 supported by the linear moving unit 9 is moved up and down by winding and loosening the wire 12B against the tension of the wire 12B, and tension is applied by the tension mechanism 11C according to the up and down movement of the linear moving unit 9. The wire 12A rotates the cam mechanism 13 and thereby rotates the mirror 8. By controlling the winding amount of the drive mechanism 62 also in this mechanism, the mechanism rotates and moves the mirror 8 up and down by one drive mechanism, and controls the scan position on the sheet surface and the optical path length in front of the lens (a). ₁ + a ₂ ) can be corrected. In this mechanism, the vertical movement is controlled by the drive mechanism 6, and the cam mechanism 13 achieves the amount of change in the rotation angle of the mirror 8 with respect to the vertical movement by the shape of the cam mechanism.

FIG. 7 is a view showing still another improvement of the mechanism shown in FIG. 5, and shows a mechanism for rotating and vertically moving the mirror 8 by one driving mechanism. This mechanism is
A rotating mirror 8 rotatably supported by a mirror rotating drum 7, a linear moving unit 9 that holds the mirror rotating drum 7 and can move up and down along a linear moving rail 10;
A tension mechanism 11B for applying an upward tension to the linear moving section 9
And a cam mechanism 13B for applying a downward tension by winding the wire 12B around the moving section 9, and a tension mechanism 11A for engaging the one end of the wire 12A to apply a rotational force to the mirror rotating drum 7 in a clockwise direction in the figure. A cam mechanism 13A for applying a downward tension to the mirror 8 by engaging the other end of the wire 12A and winding up the wire 12A; and a driving mechanism 63 for applying a driving force to rotate the cam mechanisms 13A and 13B. Is provided.

In this mechanism, the driving mechanism 63 is a cam mechanism 13A.
And 13B, the cam mechanism 13B rotates to move the linear moving part 9 up and down against the tension of the tension mechanism 11B, and the cam mechanism 13A rotates to move the mirror 8 to the tension of the tension mechanism 11A. It operates to rotate in opposition. Therefore, this mechanism can rotate and move the mirror 8 up and down by one driving mechanism to control the scan position on the sheet surface and correct the optical path length (a ₁ + a ₂ ) in front of the lens. In particular, this mechanism controls the amount of vertical movement of the mirror 8 by the outer shape of the cam mechanism 13B, and controls the amount of rotation of the mirror 8 by the outer shape of the cam mechanism 13A.

In the above description, the mechanism for rotating and vertically driving the mirror corresponding to the second embodiment has been described. However, by mounting a lens and a sensor or only a sensor on the linear moving portion, the first mechanism described above can be used. Also, the present invention can be applied to the third embodiment.

<Description of Mirror Rotation, Mirror or Sensor Up / Down Movement Control> Next, mirror rotation, mirror or sensor up / down movement control according to the first and second embodiments will be described. 8 will be described. In the figure, a document (paper) to be read is shown at a position P0 at the left end, a reference numeral 2 indicates a lens, and a read target image projected via the lens 2 at a position P3 at the right end. In the optical system shown in the figure, light emitted from the paper at the position P0 goes to a point H called the front principal point of the lens 2,
The light has a characteristic that the light travels from H ′ called the rear principal point of the lens 2 toward the image position P3. Here, assuming that a point corresponding to the focal length from the front principal point is F and a point corresponding to the focal distance from the rear principal point is F ′, these two principal points F and F ′ are the virtual center of the lens 2. Then, in the lens, (1) light parallel to the optical axis passes through the focal point (F ′ in FIG. 8), and (2) light traveling toward the center (front principal point) of the lens goes straight (actually, rearward principal). It proceeds from the point as parallel light).

Here, the forward principal point F in the optical axis direction from the position P0
The distance to the position P1 corresponding to
When the distance from the position P2 corresponding to the rear principal point in the optical axis direction to the point P3 on the image is the lens rear optical path length b and the focal length is f, the optical system forms an image such that the relation of order 3 is established. Image.

[0038]

(Equation 3)

This principle is also applied to the image scanner according to the above-described embodiment. In order to focus and read an image read from a sheet, it is necessary to rotate the mirror 8 and move it up and down or rotate the mirror 8. It is necessary to drive the lens 2 and the one-dimensional image reading sensor 3 in a predetermined relationship with respect to the vertical movement.

This will be described with reference to FIGS. 9 and 10. << Description of Control Corresponding to First Embodiment >> FIG. 9 shows a state in which the vertical position of the mirror corresponding to FIG. The example which moves the sensor 3 up and down is shown. In this case, the optical path length in front of the lens is (a ₁ + a ₂ ). The lens 2 and the one-dimensional image reading sensor 3 are moved up and down so that this value becomes constant, and the angle of the mirror 8 is controlled as shown in FIG. It is necessary to control the angle of the mirror 8 so that the light travels.

In this example, it is necessary to satisfy the following equation 4 for keeping the optical path length in front of the lens at a predetermined value k ₀ .

[0042]

(Equation 4)

Under these conditions, the relations of the following equations 5 and 6 are established by trigonometric functions.

[0044]

(Equation 5)

[0045]

(Equation 6)

Accordingly, in the present embodiment, the relationship represented by the following equation (7) is established.
Is controlled.

[0047]

(Equation 7)

[0048]

(Equation 8)

The vertical movement of the lens 2 and the one-dimensional image reading sensor 3 is controlled so that the distance from the center of rotation of the mirror 8 satisfies the following equation (9).

[0050]

(Equation 9)

FIG. 10 shows an example in which the height h of the lens 2 corresponding to FIG. 2 is kept constant, and the mirror 8 is rotated and moved up and down. In this case, the optical path length in front of the lens is also (a ₁ +
a ₂ ), and it is necessary to control the angle and height of the mirror 8 so that this value becomes constant.

<< Explanation of Control Corresponding to Embodiment 2 >> As in FIG. 9, in this embodiment, control is performed so as to maintain the relationship of the above equation (4).

Under these conditions, the following equations (10) and (11)
Is established by a trigonometric function.

[0054]

(Equation 10)

[0055]

[Equation 11]

Therefore, in the present embodiment, the relationship of the following expression 12 is established, whereby the relationship of the following expression 13 to expression 15 is established.

[0057]

(Equation 12)

[0058]

(Equation 13)

[0059]

[Equation 14]

[0060]

(Equation 15)

From these equations, sin θ is expressed by the following equation (16), and the rotation angle θ of the mirror is expressed by the following equation (17). The angle θ of the mirror 8 is controlled so as to satisfy the relation of the equation (17).

[0062]

(Equation 16)

[0063]

[Equation 17]

The height of the mirror 8 from the principal point in front of the lens 2 controls the amount of vertical movement so as to satisfy the following equation (18).

[0065]

(Equation 18)

As described above, the image scanner according to the present invention controls the mirror angle and the sensor position so that the relations of Expressions 8 and 9 are satisfied in the embodiment in which the mirror vertical position is fixed and the sensor vertical position is controlled corresponding to FIG. In the embodiment of the mirror vertical control and the fixed sensor vertical position corresponding to FIG. 2, by controlling the mirror angle and position so that the relations of Expressions 17 and 18 are established, the entire paper is focused and the paper 1 Can be received as a normal image as it is.

<Description of Drive Mechanism and Circuit Corresponding to First Embodiment> FIG. 11 shows a drive mechanism for controlling the angle of the mirror 8 and the amount of vertical movement of the lens 2 and the sensor 3 in the image scanner described in the first embodiment. FIG. 3 is a diagram for explaining a circuit. The mechanism circuit includes a one-dimensional image reading sensor driving circuit 16 that drives a sensor 3 that scans an image received through the lens 2, an amplifier circuit 14 that amplifies an image output signal from the sensor 3, A signal
A / D conversion circuit 15 for performing D / D conversion, a driving mechanism 60 including a driving motor 19A for moving the sensor 3, a driving motor driver 20A for controlling the driving mechanism 60, the lens 2, the sensor 3 and the like are integrated. A driving mechanism 61 including a motor 22 that rotates the rotating mirror 8 via a wire, a reference sensor 21A that detects a reference position for movement of the bearing portion 22, A fixed position sensor 21B for detecting the rotation angle of the rotating mirror 8, a driving circuit 20B for driving the motor 19B, and a reading control circuit for controlling these circuits and outputting an image output signal from the sensor 3 to the data line 18. 1
7 is provided.

The mechanical circuit thus configured controls the angle of the mirror 8 based on the reference angular position using the fixed position sensor 21B, and controls the vertical position of the mirror 8 and the sensor 3 based on the sensor 21A. Then, it operates to transmit the read image data to a host device or the like via the line 18.

<Description of Driving Mechanism and Circuit Corresponding to Second Embodiment> FIG. 14 is a diagram for explaining a driving mechanism and a circuit for controlling the angle and vertical movement of the mirror 8 in the image scanner described in the second embodiment. . This mechanism circuit
Sensor 3 for scanning an image received through lens 2
A one-dimensional image reading sensor driving circuit 16 for driving
Amplifying circuit 14 for amplifying an image output signal from sensor 3
An A / D conversion circuit 15 for A / D converting the image output signal, a driving mechanism 61 including a motor 19B for rotating the rotating mirror 8 via a wire, and a driving circuit 20B for controlling the driving mechanism 61. , A moving unit 10 for supporting the rotating mirror 8 and a rail 1 for linearly guiding the movement of the moving unit 9
0, a reference sensor 21A for detecting a reference position of the blade 22 disposed at one end of the moving unit 10, and a driving mechanism 60 including a motor 19A connected to the moving unit 10 via a wire and moving the mirror up and down. And a drive circuit 20A for controlling this, and a read control circuit 17 for outputting an image output signal from the sensor 3 to the data line 18.

The mechanical circuit configured in this manner controls the angle control of the mirror 8 based on the reference angular position using the fixed position sensor 21B, and controls the vertical position of the mirror 8 based on the sensor 21A for reading. The image data is transmitted to a host device or the like via the line 18.

As described above, the driving mechanism and the circuit according to the present embodiment perform the position control of the lens and the sensor (FIG. 11) or the position control of the mirror 8 in addition to the rotation control of the mirror 8 according to the above-described equations 8 and 9. Is controlled, or the mirror angle and position are controlled so that the relations of Expressions 17 and 18 are satisfied, so that the entire surface of the paper is focused and the image of the paper 1 is received as a normal image as it is. be able to. Although the driving mechanism and circuit corresponding to each of the above embodiments include the mechanism corresponding to FIGS. 5 to 7, the present invention is not limited to this.

<Description of Appearance of Image Scanner According to the Present Embodiment> FIG. 12 is a diagram showing an example of the appearance of the image scanner according to the present invention. The image scanner reads an image of the sheet 1 in an oblique state by employing an optical system having no reading unit above the sheet 1 placed on the pedestal 5. The rotating mirror 8 and the lens 2 for scanning the visual field 23 are housed inside the scanner main body 24. The image processing / recognition device 25 performs image processing such as correction of uneven brightness of the image (shading correction), contour enhancement, binarization, and the like, and passes the image data to the recognition processing 26.
In the recognition process 26, a form reading process such as character recognition is performed based on the obtained image data. An example of these processes will be described with reference to the flowchart of FIG. In this process, an installer who has installed a paper image such as a form at a fixed position instructs reading using a reading start button or the like (step 131). This causes the scanner unit to read the image (step 132).
A read image is displayed once to check whether the installed paper is appropriate for the task at that time, whether necessary items are filled in, and whether the installation direction is correct (step 133). As a result, the image processing and the recognition processing are performed on those which are determined to be sufficient, and the results are shown in FIG.
It operates to transfer the read result from the second data line 27 to the external device (steps 134 to 137).

The present invention can be represented by the following embodiments. <Embodiment 1> A form reading apparatus comprising: an optical system that moves an image reading unit from the center of a form reading range when reading a form image, thereby eliminating the image reading unit from the front side of the image paper. The distance between the rotating mirror that scans the paper surface and the paper surface is kept constant to prevent image degradation and changes in image dimensions caused by out-of-focus caused by changes in the paper surface distance that the image reading unit scans. A form reading device comprising a moving mechanism for moving a light receiving sensor unit including a lens in order to maintain the position.

<Second Embodiment> A form reading apparatus according to the first embodiment, wherein the mechanism for keeping the distance to the paper sheet constant is a mirror that rotates and moves linearly.

<Embodiment 3> Form reading characterized by having an optical system for moving the image reading section from the center of the form reading range when reading a form image, thereby eliminating the image reading section from the front side of the image paper. In the device, image reading is performed while changing the distance between the lens and the light receiving sensor to meet the change of the paper surface distance between the rotating mirror that scans the paper surface and the paper surface that the image reading unit scans and satisfy the imaging conditions of the optical system. <Embodiment 4> In the image reading apparatus according to Embodiments 1 to 3, the sub-scanning interval on the sheet surface read by the light receiving sensor for each main scan is constant. A form reading apparatus characterized by controlling the angle of a rotating mirror.

[0076]

As described above, according to the present invention, there is provided a mirror for reflecting an image on a sheet and a one-dimensional sensor for optically reading an image reflected by the mirror via a lens. In an image scanner in which an optical system including a sensor is separated from the center of an image reading range, a lens and / or a sensor is moved so that a distance between a rotating mirror that scans a sheet surface and a sheet surface is kept constant. Controlling the sensor and lens vertical position so that the distance between the mirror and the rotating mirror that scans the paper surface with the distance between the mirrors fixed with the distance between the lenses fixed, the distance between the sensor and the lens fixed By controlling the vertical position of the mirror so that the distance between the lens and the rotating mirror that scans the paper surface and the distance to the paper surface are kept constant, DOO can scan the image was on the whole surface. Further, the sheet installer can read the sheet while checking the sheet to be read, and the operability and safety of the scanner are ensured because the reading is performed in an oblique direction. In addition, the reading unit will be removed from the person who installs the paper form and the customer who is facing him, making it unnecessary to be aware of the existence of the reading device, and free to layout at places such as bank shops and other places where foreign visitors can see. The degree can be increased.

[Brief description of the drawings]

FIG. 1 is a view for explaining a first embodiment of an image scanner according to the present invention.

FIG. 2 is a view for explaining a second embodiment of the image scanner according to the present invention.

FIG. 3 is a diagram for explaining an image scanner according to the related art.

FIG. 4 is a diagram for explaining a third embodiment of the image scanner according to the present invention.

FIG. 5 is a view for explaining an embodiment of a mirror up / down and rotation mechanism of the image scanner according to the present invention.

FIG. 6 is a view for explaining an embodiment of a mirror up / down and rotation mechanism of the image scanner according to the present invention.

FIG. 7 is a diagram illustrating an embodiment of a mirror up / down and rotation mechanism of the image scanner according to the present invention.

FIG. 8 is a diagram for explaining an image forming state of an optical system using a lens.

FIG. 9 is an arrangement diagram of an optical system for describing correction contents of the optical system according to the embodiment.

FIG. 10 is an arrangement diagram of an optical system for describing correction contents of the optical system according to the embodiment.

FIG. 11 is a view for explaining a mechanism circuit for performing mirror angle control and movement amount control of a sensor and the like according to the embodiment;

FIG. 12 is a view for explaining the appearance of the image scanner according to the embodiment of the present invention.

FIG. 13 is a view for explaining processing of the image scanner according to the present invention.

FIG. 14 is a diagram for explaining a mechanism circuit for performing mirror angle control and movement amount control of a sensor and the like according to the embodiment;

[Explanation of symbols]

1: paper, 2: lens, 3, 3 ', one-dimensional image reading sensor, 4: image sensor moving mechanism, 5: pedestal, 6, 6A,
6B: drive mechanism, 7: mirror rotating drum, 8: rotating mirror, 9: linear moving section, 10: linear moving rail, 11,1
1A, 11B: tension mechanism, 12A, 12B: wire, 1
3, 13A, 13B: cam mechanism, 14: amplifier circuit, 15:
A / D conversion circuit, 16: one-dimensional image reading sensor driving circuit, 17: reading control circuit, 18: image data line, 19: driving motor, 20: driving motor driver, 21: fixed position sensor, 22: blade, 23 : Field of view, 24: scanner housing, 25: image processing / recognition device,
26: display device, 27: data line

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B047 AA27 AA30 BA02 BB02 BB09 BC05 BC16 CA08 CA11 CA13 CA17 CB05 DC07 5C072 AA01 DA02 DA04 DA21 DA23 HA12 HB15 JA07 NA01 NA04 RA12 XA10

Claims (4)

[Claims] A mirror for reflecting an image on a sheet of paper and a one-dimensional sensor for optically reading, via a lens, an image reflected by the mirror; In an image scanner that separates from the center and scans and receives an image on a sheet by rotation of the mirror, the distance between the rotation axis of the mirror and the sheet, and the distance between the lens and the sensor are fixed. An image scanner wherein a lens and a sensor are moved with respect to a rotation axis of a mirror so that a distance to a sheet surface is kept constant. 2. A mirror for reflecting an image on a sheet of paper and a one-dimensional sensor for optically reading an image reflected by the mirror via a lens, and an optical system including the lens and the sensor is provided in an image reading range. In an image scanner that separates from the center and scans and receives an image on a sheet by rotating the mirror, the distance between the rotation axis of the mirror and the sheet is configured to be variable, and the distance between the lens and the sensor and the lens An image scanner wherein the rotation axis of the mirror is moved relative to the lens so that the distance from the lens to the paper surface is kept constant while the sensor is fixed. 3. A mirror for reflecting an image on a sheet of paper and a one-dimensional sensor for optically reading an image reflected by the mirror via a lens, and an optical system including the lens and the sensor is provided in an image reading range. In an image scanner that separates from the center and scans and receives an image on a sheet by rotating the mirror, the sensor is moved relative to the lens with the distance between the rotation axis of the mirror and the sheet and the lens fixed. An image scanner characterized in that the image scanner is configured to perform the following. 4. The image scanner according to claim 1, wherein the rotation of the mirror performs angle control such that the surface of the sheet is scanned at a constant speed.