JP2009302695A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus which is hard to receive influence of a wrinkle or a crease of a reading target surface, and can carry out more desirable image reading. <P>SOLUTION: The image reading apparatus A includes: a light guiding member 31 which emits light from a light source to a reading object P as line-shaped light which prolongs to a main scanning direction; a light-receiving means 50 arranged along the main scanning direction; and a lens material 41 which collects reflection light from the reading target P to the light-receiving means 50. It includes a reflection member 21 prepared on an opposite side of the light guiding member 31 placing the lens member 41 therebetween. The light guiding member 31 has a first light-emitting plane 31a which emits the line-shaped light to the reading target P, and a second light-emitting plane 31b which emits the line-shaped light to the reflection member 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus used for reading checks, banknotes, and the like.

  FIG. 2 is a cross-sectional view showing an example of a conventional image reading apparatus (see, for example, Patent Document 1). The image reading apparatus X shown in the figure includes a substrate 91, a case 92, a light guide member 93, a lens member 94, a sensor chip 95, and a glass cover 96. The substrate 91 is made of, for example, ceramic and has a sensor chip 95 mounted on the surface. The light guide member 93 can emit light from a light source (not shown) as linear light extending in the main scanning direction. The image reading apparatus X is configured to emit linear light toward a reading target and form an image of the reflected light on a sensor chip 95 by a lens member 94. The sensor chip 95 is configured to generate an electromotive force corresponding to the received light and to output a luminance signal for each pixel from the electromotive force. By receiving the light reflected by the reading object by the sensor chip 95, the description content of the reading object can be read as image data.

  However, when the reading target is a check or bill, the surface of the reading target is often wrinkled or creased, and when the linear light emitted from the light guide member 93 is irradiated, There was sometimes a shadow on the surface. For this reason, in the image reading apparatus X, a dark part may occur in the obtained image.

JP 2004-266313 A

  The present invention has been conceived under the circumstances described above, and provides an image reading apparatus that is less susceptible to wrinkles and folds on the surface of the reading object and can perform more preferable image reading. That is the issue.

  An image reading apparatus provided by the present invention includes a light guide member that emits light from a light source to a reading object as linear light extending in the main scanning direction, light receiving means arranged along the main scanning direction, and A lens member for converging the reflected light from the reading target on the light receiving means, and a reflection member provided on the opposite side of the light guide member across the lens member. The light guide member has a first emission surface that emits linear light toward the reading object and a second emission surface that emits linear light toward the reflection member. It is characterized by.

  According to such a configuration, the reading object differs depending on the linear light emitted from the first emission surface and the linear light emitted from the second emission surface and reflected by the reflecting member. Illuminated from two directions. For this reason, it is difficult to make a shadow on the surface to be read, and the image reading apparatus is less susceptible to wrinkles and folds on the surface to be read, and can perform more preferable image reading.

  In a preferred embodiment of the present invention, the second emission surface is formed such that an inclination angle with respect to the reading object is smaller than an inclination angle of the first emission surface with respect to the reading object. . According to such a configuration, the emission direction of the linear light emitted from the first emission surface is different from the emission direction of the linear light emitted from the second emission surface relatively easily. It becomes possible to set the direction.

  In a preferred embodiment of the present invention, the reflection member has a reflection surface that is inclined so as to be farther from the lens member in the sub-scanning direction as it approaches the reading object. According to such a configuration, it is possible to prevent the light reflected by the reflecting member from entering the lens member inappropriately.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  FIG. 1 shows an example of an image reading apparatus according to the present invention. The image reading apparatus A shown in FIG. 1 includes a substrate 10, a case 20, a linear light source 30, a lens unit 40, a sensor chip 50, and a glass cover 60. In FIG. 1, a direction perpendicular to the paper surface is a main scanning direction of the image reading apparatus A, and an x direction that is a sub-scanning direction and a y direction that is orthogonal to the x direction are illustrated. In FIG. 1, a paper-like reading object P having a predetermined thickness in the y direction and extending along the x direction is indicated by a virtual line. The image reading apparatus A irradiates the reading line of the reading target P positioned directly above the sensor chip 50 while moving the reading target P along the x direction, and reads an image for each reading line.

  The substrate 10 is made of, for example, ceramic and extends in the main scanning direction of the image reading apparatus A, and has a long plate shape having a predetermined width in the x direction and a predetermined thickness in the y direction. A wiring pattern (not shown) is formed on the surface of the substrate 10, and the sensor chip 50 is mounted at a position near one end in the x direction.

  The case 20 includes a linear light source 30, a lens unit 40, and a reflecting member 21 arranged in order in the x direction, and has a substantially rectangular parallelepiped shape extending in the main scanning direction. The case 20 has an opening 22 above in the y direction and an opening 23 below in the y direction. A glass cover 60 is fitted in the opening 22, and the substrate 10 is fitted in the opening 23. The case 20 is made of, for example, a black resin.

  The reflecting member 21 is provided on the opposite side of the linear light source 30 across the sensor chip 50 in the x direction, and is disposed below the glass cover 60 of the opening 22 in the y direction. The reflecting member 21 is formed of, for example, white resin, and has a reflecting surface 21a that is inclined so as to be directed upward in the y direction toward one side in the x direction. The reflecting member 21 reflects a part of the light coming from the linear light source 30 toward the reading line of the reading target P as scattered light.

  The linear light source 30 includes a light guide member 31, a reflector 32, and an LED module (not shown). The light guide member 31 is made of a transparent resin such as methyl methacrylate resin (PMMA), for example, and is configured to emit light from an LED module (not shown) toward the reading target as linear light along the main scanning direction. ing. The reflector 32 is formed of, for example, a white resin and is fitted in a proper position of the case 20. The reflector 32 is accommodated so as to hold the light guide member 31, and prevents light traveling in the light guide member 31 from being unduly leaked. An LED module (not shown) includes, for example, LED chips that emit red light, blue light, and green light, and is mounted on the substrate 10 so that light can be emitted toward the light guide member 31.

  The light guide member 31 has a first emission surface 31a and a second emission surface 31b at one end in the main emission direction inclined by 45 ° with respect to the x direction, and a reflecting portion 31c at the other end. I have. The light guide member 31 is configured to travel in the main scanning direction while irregularly reflecting light from an LED module (not shown), and to reflect a part thereof in the main emission direction by the reflecting portion 31c. The light reflected toward the main emission direction in the reflection part 31c is emitted to the outside from the first emission surface 31a and the second emission surface 31b. The first emission surface 31 a is formed so as to emit linear light toward the reading target P. On the other hand, the second emission surface 31b is inclined with respect to the x direction at a smaller angle than the inclination angle of the first emission surface 31a with respect to the x direction, and emits linear light toward the reflection surface 21a. It is formed as follows.

  The lens unit 40 includes a lens member 41 that converges linear light reflected by the reading target P onto the sensor chip 50 and a lens holder 42 that holds the lens member 41. The lens unit 40 is disposed at the same position as the sensor chip 50 in the x direction, and is disposed below the reflecting member 21 by a predetermined length in the y direction. The lens member 41 is composed of, for example, a plurality of cylindrical lenses arranged in the main scanning direction. The lens holder 42 is a resin housing, for example, and holds the lens member 41 sandwiched in the x direction. The upper end of the lens holder 42 in the y direction is located higher in the y direction than the upper end of the lens member 41 in the y direction.

  The sensor chip 50 is light receiving means according to the present invention disposed on the substrate 10 so as to extend in the main scanning direction. The sensor chip 50 is configured to generate an electromotive force corresponding to the received light, and to output a luminance signal for each pixel from the electromotive force to the outside through a wiring pattern on the substrate 10 and a connector (not shown). For this reason, when the light reflected by the reading object P is received by the sensor chip 50, the description content of the reading object P can be read as image data.

  The glass cover 60 protects the inside of the case 20, and the reading object P is mounted on the surface thereof so as to be movable along the x direction.

  Next, the operation of the image reading apparatus A will be described.

  According to the present embodiment, the reading line of the reading object P is illuminated by the linear light emitted from the emission surface 31a and the scattered light emitted from the emission surface 31b and reflected by the reflection surface 21a. Since the reflected light from the reflecting surface 21a illuminates the reading object P from the side where the linear light emitted from the emitting surface 31a creates a shadow, even if there are wrinkles or folds on the surface of the reading object P, It is difficult for shadows to be formed on the surface of the reading object P. For this reason, the image reading apparatus A is less susceptible to wrinkles and folds on the surface of the reading target P, and can perform more preferable image reading.

  Furthermore, according to the present embodiment, the reflecting member 21 is a white resin, and the light reflected by the reflecting surface 21a is scattered light. Therefore, the light that illuminates the reading line of the reading target P is in the main scanning direction. The amount of light is difficult to vary along. Therefore, the image reading apparatus A can illuminate the reading object P with more uniform light along the main scanning direction, and can perform a more preferable image reading.

  Furthermore, according to the present embodiment, the lens member 41 and the reflecting member 21 are separated from each other, and the reflecting member 21 is inclined in a direction in which it is difficult to reflect light downward in the y direction. The reflected light is less likely to enter the lens member 41 inappropriately. For this reason, the image reading apparatus A can perform a more preferable image reading.

  Furthermore, according to the present embodiment, by forming the first emission surface 31a and the second emission surface 31b having different inclinations at one end in the main emission direction of the light guide member 31, The linear light can be easily emitted in two different directions.

  The image reading apparatus according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the image reading apparatus according to the present invention can be varied in design in various ways. For example, the position of the reflecting member 21 in the x direction can be adjusted as appropriate.

It is sectional drawing which shows an example of the image reading apparatus concerning this invention. It is sectional drawing which shows an example of the conventional image reading apparatus.

Explanation of symbols

A Image reading device 10 Substrate 20 Case 21 Reflective member 21a Reflective surfaces 22, 23 Opening 30 Linear light source 31 Light guide members 31a, 31b Ejecting surface 31c Reflector 32 Reflector 40 Lens unit 41 Lens member 42 Lens holder 50 Sensor chip Light receiving means)
60 Glass cover

Claims (3)

A light guide member that emits light from the light source to the reading target as linear light extending in the main scanning direction;
A light receiving means arranged along the main scanning direction;
A lens member for converging reflected light from the reading object on the light receiving means;
An image reading apparatus comprising:
A reflection member provided on the opposite side of the light guide member across the lens member;
The light guide member has a first emission surface that emits linear light toward the reading target and a second emission surface that emits linear light toward the reflection member. An image reading apparatus as a feature.   2. The image reading apparatus according to claim 1, wherein the second emission surface is formed such that an inclination angle with respect to the reading object is smaller than an inclination angle of the first emission surface with respect to the reading object. .   The image reading apparatus according to claim 1, wherein the reflection member has a reflection surface that is inclined so as to be away from the lens member in a sub-scanning direction as the reading object is approached.

Images