JP2015032875A - Image sensor head and reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image sensor head with improved heat radiation performance.SOLUTION: The image sensor head includes: a glass plate 1 in which a reading medium 23 passes along its surface; a light-emitting element substrate 3 holding a light-emitting element 5 which radiates light to the reading medium 23 through the glass plate 1; a light-receiving element substrate 7 holding a light receiving element 9 which receives the light reflected by the reading medium 23 through the glass plate 1; and a heat sink 11 which is connected with the light-emitting element substrate 3 and is used for radiating heat generated by the light-emitting element 5. The heat sink 11 is disposed adjacent to the glass plate 1 in a sub-scanning direction.

Description

  The present invention relates to an image sensor head and a reading device.

  In recent years, there has been known an image sensor head that uniformly emits light from a light emitting element as a light source to a reading medium. The image sensor head includes a glass plate through which a reading medium passes along a surface, a light emitting element substrate that holds a light emitting element that irradiates light to the reading medium through the glass plate, and light reflected from the reading medium in glass. A light receiving element substrate that holds a light receiving element that receives light through a substrate is known (for example, see Patent Document 1).

  Moreover, what is equipped with the heat sink for radiating the heat which is connected to a light emitting element substrate and the light emitting element produces is also known (for example, refer patent document 2).

Japanese Patent Laid-Open No. 06-233071 JP-A 63-196166

  However, the above-described image sensor head may still not have sufficient heat dissipation.

  An image sensor head according to an embodiment of the present invention includes a glass plate through which a reading medium passes along a surface, a light emitting element substrate that holds a light emitting element that irradiates light to the reading medium through the glass plate, A light receiving element substrate that holds a light receiving element that receives light reflected from the reading medium via a glass substrate, and a heat radiating plate that is connected to the light emitting element substrate and radiates heat generated by the light emitting element. I have. The heat radiating plate is disposed adjacent to the glass plate in the sub-scanning direction.

  In addition, a reading apparatus according to an embodiment of the present invention includes the image sensor head described above and a drive unit that drives the image sensor head or the reading medium in a sub-scanning direction.

  According to the present invention, an image sensor head with improved heat dissipation can be provided.

1 is a schematic perspective view showing an image sensor head according to a first embodiment of the present invention. (A) is a top view of the light receiving element substrate which comprises the image sensor head shown in FIG. 1, (b) is a top view of the light emitting element substrate which comprises the image sensor head shown in FIG. It is the II sectional view taken on the line shown in FIG. FIG. 2 is a schematic perspective view illustrating a state in which a reading medium is conveyed to the image sensor head illustrated in FIG. 1. 1 is a schematic perspective view showing a reading apparatus according to a first embodiment of the present invention. (A) is a top view of the light emitting element substrate which comprises the image sensor head which concerns on 2nd Embodiment, (b) is a top view of the light emitting element substrate which comprises the image sensor head which concerns on 1st Embodiment. is there. FIG. 5 is a cross-sectional view illustrating an image sensor head according to a third embodiment of the present invention and corresponding to FIG. 2.

<First Embodiment>
Hereinafter, the image sensor head X1 will be described with reference to FIGS.

  As shown in FIG. 1, the image sensor head X <b> 1 includes a glass plate 1, a light emitting element substrate 3, a light receiving element substrate 7, a heat radiating plate 11, and a frame member 13. In the image sensor head X1, a frame member 13 is disposed so as to cover the light receiving element substrate 7, and the glass plate 1 and the light emitting element substrate 3 are disposed on the upper surface of the frame member 13. A heat radiating plate 11 is disposed on the upper surface of the light emitting element substrate 3.

  The glass plate 1 is formed long in the main scanning direction and has a rectangular shape in plan view. As shown in FIG. 1, the glass plate 1 is placed on protruding portions (not shown) protruding from the upper surface of the frame member 13 at both ends in the main scanning direction. As the glass plate 1, a plate glass can be used.

  The light emitting element substrate 3 is formed long in the main scanning direction, and has a rectangular shape in plan view. The light emitting element substrate 3 is placed in a region adjacent to the protruding portion 13a protruding from the upper surface of the frame member 13 at both ends in the main scanning direction. As shown in FIG. 2B, a plurality of light emitting elements 5 are arranged on the upper surface 3 a of the light emitting element substrate 3 at a predetermined interval, and the light emitting element substrate 3 has a function of holding the light emitting elements 5. have. As shown in FIG. 3, the light emitting element substrate 3 is placed so that the upper surface 3 a on which the light emitting element 5 is mounted faces the upper surface of the frame member 13.

  The light emitting element substrate 3 can be formed of a substrate made of alumina ceramic, glass ceramic, glass epoxy, metal, or the like. The light emitting element substrate 3 preferably uses a material having high thermal conductivity, and preferably uses a metal substrate in order to efficiently release the heat generated from the light emitting element 5.

  The light emitting element 5 has a function of irradiating the reading medium 23 (see FIG. 4) with light, and examples thereof include a light emitting diode (LED). As shown in FIG. 2B, the light emitting element 5 has a rectangular shape in plan view, and includes a pair of long sides 5a and a pair of short sides 5b. The light emitting element 5 is provided on the upper surface 3a of the light emitting element substrate 3 so that the long side 5a is along the main scanning direction. In addition, you may use the light guide formed with organic materials, such as glass, translucent ceramics, or an acrylic resin, between the light emitting elements 5. FIG.

  A heat radiating plate 11 for radiating heat generated by the light emitting element 5 is provided on the upper surface of the light emitting element substrate 3. The heat radiating plate 11 is made of a material having high thermal conductivity, and is made of a metal, an alloy, a cermet, or a resin material.

The heat sink 11 is formed long in the main scanning direction, and has a rectangular shape in plan view. In order to efficiently dissipate the heat of the light emitting element substrate 3, the radiator plate 11 preferably has a planar view area that is equal to or greater than that of the light emitting element substrate 3. And since the heat sink 11 is provided on the lower surface 3b of the light emitting element substrate 3, as shown in FIG. 3, the image sensor head X1 has the heat sink 11 and the glass plate 1 in the sub-scanning direction. They are arranged next to each other.

  The light receiving element substrate 7 is disposed so as to be covered with the frame member 13 and has a rectangular shape in plan view. As shown in FIG. 2A, a plurality of light receiving elements 9 are arranged on the upper surface 7 a of the light receiving element substrate 7 at a predetermined interval, and the light receiving element substrate 7 has a function of holding the light receiving elements 9. have. The light receiving element substrate 7 can be formed of the same material as the light emitting element substrate 3.

  The light receiving element 9 has a function of photoelectrically converting the reflected light reflected by the reading medium 23 and converting it into an electric signal. As the light receiving element 9, a solid-state image sensor can be exemplified, and a CCD image sensor head or a CMOS image sensor head can be exemplified.

  The frame member 13 has a function of holding the glass plate 1, the light emitting element substrate 3, the light receiving element substrate 7, and the heat radiating plate 11. The frame member 13 can be formed of a resin material, ceramics, metal, or the like. The inner surface of the frame member 13 is preferably roughened so that the light emitted from the light emitting elements 5 does not interfere with each other, and a black paint is applied to the inner surface of the frame member 13 so as to absorb the light. It is preferable.

  The image sensor head X1 will be described in detail with reference to FIGS.

  As shown in FIG. 3, a lens holding member 15 is provided so as to cover the light receiving element substrate 7, and a frame member 13 is provided so as to accommodate the lens holding member 15. The lens holding member 13 has an opening at the center in the sub-scanning direction, and the lens 17 is disposed in the opening. The opening of the lens holding member 13 and the lens 17 are disposed above the light receiving element 9.

  A reflector 19 is placed on the upper surface of the lens holding member 13 so as to face the light emitting element 5, and a reflecting surface 19 a of the reflector 19 faces the light emitting element 5. A diffusion plate 21 is provided at the center of the lens holding unit 15 in the sub-scanning direction, and has a function of diffusing reflected light reflected by the reflector 19. Therefore, the variation in luminous intensity in the main scanning direction can be reduced.

  The lens holding member 15 can be formed of a resin material, ceramics, metal, or the like, like the frame member 13. In view of thermal expansion due to heat of the light emitting element 5, it is preferable that the lens holding member 15 and the frame member 13 are formed of the same material.

  The lens 17 has a function of forming an image of light reflected from the reading medium 23 and supplying it to the light receiving element 9. As the lens 17, a gradient index lens array can be exemplified.

  The reflector 19 has a reflecting surface 19 a on the upper surface, and has a function of supplying the light emitted from the light emitting element 5 to the reading medium 23 through the glass plate 1. The reflector 19 is preferably mirror-finished on the reflecting surface 19a in order to improve the reflectance.

  The diffusion plate 21 has a function of diffusing the light reflected by the reflector 19. By diffusing the light reflected by the reflector 19 by the diffuser plate 21, it is possible to reduce the variation in luminous intensity that occurs in the main scanning direction. Although not shown, the diffusion plate 21 is provided so as to extend in the main scanning direction, and is provided over the entire area of the image sensor head X1.

  The image sensor head X1 reads the reading medium 23 by the following operation.

  First, the light emitting element 5 is driven to emit light from the light emitting element 5. The emitted light travels downward and is reflected by the reflecting surface 19a of the reflector 19 toward the central portion in the sub-scanning direction. The light reflected by the reflector 19 reaches the glass plate 1 while part of the light is diffused by the diffusion plate 21. The light that reaches the glass plate 1 illuminates the reading medium 23 that passes along the surface 1 a of the glass plate 1.

  The light that illuminates the reading medium 23 is reflected downward by the reading medium 23. The light reflected by the reading medium 23 travels downward while passing through the glass plate 1, is imaged by the lens 17, and is supplied to the light receiving element 9. Thereby, the image information of the reading medium 23 is converted into an electric signal via light, and the image sensor head X1 reads the reading medium 23.

  In recent years, in order to read a reading medium precisely and to read the reading medium at high speed, the illumination of the image sensor head is required to increase the amount of light, and the light emitting element emits a large amount of light. Or the output of the light-emitting element may be increased. And with the increase in the amount of illumination of the image sensor head, heat may accumulate on the light emitting element substrate.

  On the other hand, the image sensor head X1 is provided with the heat radiating plate 11 on the light emitting element substrate 3, and can radiate the heat accumulated in the light emitting element substrate 3. Further, since the heat radiating plate 11 is disposed adjacent to the glass plate 1 in the sub-scanning direction, the heat radiating plate 11 comes into contact with the outside air, and the heat accumulated in the light emitting element substrate 3 is efficiently radiated. can do.

  Particularly, since the heat radiating plate 11 is disposed adjacent to the glass plate 1 in the sub-scanning direction, when the reading medium 23 is conveyed in the conveying direction R (see FIG. 4), the reading medium 23 is conveyed. The airflow generated along with this comes into contact with the heat radiating plate 11 and can efficiently radiate heat. Further, even when the heat radiating plate 11 and the reading medium 23 are in contact with each other, the heat of the light emitting element substrate 3 can be radiated through the reading medium 23.

  In the image sensor head X1, the light emitting element substrate 3 is disposed on both sides of the glass plate 1 in the sub-scanning direction, and the heat radiating plate 11 is connected to each of the light emitting element substrate 3. Therefore, the light emission amount of the image sensor head X1 can be increased, and the heat generated in the light emitting element substrate 3 can be efficiently radiated by the heat radiating plate 11.

  Further, since light can be emitted from the both sides of the glass plate 1 by the light emitting element 5, it is possible to reduce the possibility of variations in the light emission amount in the image sensor head X1.

  In the image sensor head X1, the reflector 19 is disposed below the light emitting element substrate 3. The light emitted from the light emitting element 5 is reflected by the reflector 19, and the light reflected by the reflector 19 is The light is emitted to the reading medium 23 through the glass plate 1. Therefore, the optical path from the light emitting element 5 to the reading medium 23 can be lengthened.

  Thus, the image sensor head X1 dissipates heat efficiently by arranging the light emitting element substrate 3 provided with the heat dissipation plate 11 so as to be adjacent to the glass plate 1, and the reflector 19 as described above. By arranging, the optical path length can be secured.

Further, in the image sensor head X1, the frame member 13 holds the glass plate 1, the light emitting element substrate 3, and the heat radiating plate 11, and the height position of the surface 1a of the glass plate 1 is the surface 11a of the heat radiating plate 11.
Higher than the height position. Therefore, as shown in FIG. 4, a space 25 is generated between the reading medium 23 and the heat radiating plate 11, and the possibility of bringing an air flow into contact with the heat radiating plate 11 can be increased.

  In the image sensor head X1, the example in which the height position of the surface 1a of the glass plate 1 is higher than the height position of the surface 11a of the heat sink 11 is shown, but the present invention is not limited to this. For example, the surface 1a of the glass plate 1 and the surface 11a of the heat sink 11 may exist on the same plane.

  Even in such a case, after the reading medium 23 is transported, an air flow is generated in the transport direction R. However, the generated air flow can be brought into contact with the heat radiating plate 11, and heat can be efficiently radiated.

  In addition, as shown in FIGS. 3 and 4, the image sensor head X <b> 1 is arranged in a state where the glass plate 1 and the heat radiating plate 11 are separated with a space 27 therebetween. Therefore, even when thermal expansion occurs in the heat radiating plate 11 due to heat generation of the light emitting element substrate 3, the space 27 is present, so that the possibility that the heat radiating plate 11 contacts the glass plate 1 can be reduced. The possibility that the glass plate 1 is broken can be reduced.

  An adhesive or a double-sided tape may be disposed in the space 27 provided between the glass plate 1 and the heat radiating plate 11. Even in that case, the possibility that the glass plate 1 is damaged can be reduced by elastic deformation of the adhesive or the double-sided tape.

  An electronic blackboard will be described as an example of the reading device Y1 including the image sensor head X1 with reference to FIG.

  The reading device Y1 includes an image sensor head X1 and a drive unit 33 that drives the image sensor head X1 in the sub-scanning direction that is the reading direction.

  The surface 1a of the glass plate 1 of the image sensor head X1 and the reading surface 31 of the reading device Y1 are disposed so as to face each other, and a drive unit 33 is connected to the upper part of the image sensor head X1.

  The drive unit 33 is provided so that the image sensor head X1 moves in the sub-scanning direction on the reading surface 31 of the reading device Y1. The drive unit 33 has wheels (not shown) arranged on guide rails (not shown) of the reading device Y1, and drives a drive mechanism (not shown) such as a motor to thereby drive the image sensor on the reading surface 31. The head X1 can be moved in the sub-scanning direction. The drive unit 33 may be provided inside the image sensor head X1.

  When reading the image or the like written on the reading surface 31, the reading device Y <b> 1 first reads a one-line image or the like having a width corresponding to one pixel in a linear form. Next, the control unit operates the driving unit 33 to read the pixels adjacent to the read one line, and operates the driving unit 33 so that the reading device Y1 moves on the guide rail by one pixel. Let Then, the reading device Y1 reads the reading medium 23 such as an image at the position to be read. By repeating this operation a plurality of times, the entire image or the like is read.

In addition, although the example of the electronic blackboard was shown as reading apparatus Y1, you may use this technique for a multifunction device etc. In this case, the image sensor head X1 is fixed to the multifunction peripheral, and the driving unit 33 reads the reading medium 23 by driving the reading medium 23 in the transport direction that is the main scanning direction. Moreover, although the image sensor head X1 provided with the cover glass 1 (refer FIG. 1) was illustrated, the image sensor head X1 does not need to be provided with the cover glass 1. FIG.

<Second Embodiment>
The image sensor head X2 will be described with reference to FIG. The image sensor head X2 is different from the image sensor head X1 in the arrangement of the light emitting elements 105 arranged on the light emitting element substrate 103, and the other points are the same. In addition, the same code | symbol is attached | subjected about the same member and it is the same below.

  As shown in FIG. 6A, the image sensor head X2 has the orientation of the light emitting element 105 arranged in the central region D1 (hereinafter sometimes referred to as the central region D1) in the main scanning direction of the light emitting element substrate 103. The direction of the light emitting element 105 arranged in the end region D2 (hereinafter sometimes referred to as end region D2) in the main scanning direction of the light emitting element substrate 103 is different.

  Specifically, the light emitting element 105 located in the central region D1 in the main scanning direction of the light emitting element substrate 103 is arranged so that the long side 105a is along the main scanning direction. In addition, the light emitting element 105 located in the end region D2 in the main scanning direction of the light emitting element substrate 103 is arranged so that the short side 105b is along the main scanning direction.

  Therefore, compared with the image sensor head X1 shown in FIG. 6B, the number of the light emitting elements 105 in which the end region D2 is positioned is increased without shortening the interval between the light emitting elements 105 in the end region D2. be able to. As a result, the amount of light in the end region D2 where the amount of light tends to decrease can be increased, and variations in the amount of light in the main scanning direction can be reduced.

  Note that the end region D2 of the light emitting element substrate 103 indicates a region of 5 to 20% from the end in the main scanning direction of the light emitting element substrate 103, and the central region D1 of the light emitting element substrate 103 is the end region D2. A region of 60 to 90% in the main scanning direction of the light emitting element substrate 103 excluding the symbol is shown.

<Third Embodiment>
The image sensor head X3 will be described with reference to FIG. The image sensor head X3 is different from the image sensor head X1 in that a heat dissipation member 29 is disposed between the light emitting element substrate 3 and the heat dissipation plate 11, and other points are the same.

  In the image sensor head X <b> 3, a heat radiating member 29 is disposed between the light emitting element substrate 3 and the heat radiating plate 11. The heat radiating member 29 is provided over the entire area between the light emitting element substrate 3 and the heat radiating plate 11, and has a function of radiating the heat of the light emitting element substrate 3 to the heat radiating plate 11.

  As the heat radiating member 29, a member having high thermal conductivity can be used. For example, an organic resin such as epoxy can be used. Further, in order to improve the thermal conductivity, a filler or a filler may be contained in the organic resin. Specifically, the heat radiating member 29 containing a heat conductive filler in a polymer can be used. The thermal conductivity of these members is preferably 0.8 to 4.0 (W / m · K). In addition, in the case of the thermal radiation member 29 which contains a heat conductive filler in the high molecular polymer mentioned above, heat conductivity is 3.0 (W / m * K).

  As described above, by interposing the heat radiating member 29 between the light emitting element substrate 3 and the heat radiating plate 11, the heat of the light emitting element substrate 3 can be efficiently radiated to the heat radiating plate 11. This is because when the light emitting element substrate 3 and the heat sink 11 are connected using a double-sided tape, the thermal conductivity of the double-sided tape is about 0.1 to 0.6 (W / m · K). Compared with the case where it connects by, it can thermally radiate to the heat sink 11 efficiently.

  Further, a heat radiating member 29 may be interposed in the space 27 between the glass plate 1 and the heat radiating plate 11. Even in this case, the heat of the heat radiating plate 1 can be radiated to the glass plate 1. In addition, when the heat radiating member 29 is interposed in the space 27 between the glass plate 1 and the heat radiating plate 11, in consideration of the possibility that the heat radiating plate 11 is thermally expanded, a polymer polymer containing a heat conductive filler is used. It is preferable to use it. In this case, a heat conductive filler functions as an elastic member, and it can reduce possibility that the glass plate 1 will be damaged.

  Note that a heat dissipation member 29 may be interposed between the light emitting element substrate 3 and the frame member 13. Even in this case, the heat of the light emitting element substrate 3 can be radiated to the frame member 13.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. For example, the reading device Y1 using the image sensor head X1 has been described, but the reading device Y1 using the image sensor heads X2 and X3 may be used. Further, the embodiments X1 to X3 may be arbitrarily combined, and a combination of these is considered to be described in the present specification.

  For example, the image sensor head X2 and the image sensor head X3 may be combined. That is, in the image sensor head X2 in which the number of light emitting elements 105 in the end region D2 is larger than the number of light emitting elements 105 in the central region D1, only the end region D2 is provided between the light emitting element substrate 103 and the heat dissipation plate 11. A heat radiating member 29 may be interposed.

  In this case, a double-sided tape is interposed between the central region D1 of the light emitting element substrate 103 and the heat radiating plate 11, and a heat radiating member 29 is interposed between the end region D2 of the light emitting element substrate 103 and the heat radiating plate 11. The double-sided tape can efficiently dissipate the heat of the end region D2 of the light-emitting element substrate 103 having a high temperature while strengthening the bonding between the light-emitting element substrate 103 and the heat dissipation plate 11. Further, by reducing the bonding strength between the end region D2 of the light emitting element substrate 103 and the heat radiating plate 11, the light emitting element substrate 103 and the heat radiating plate 11 are connected even when thermal expansion occurs in the heat radiating plate 11. The possibility of peeling can be reduced.

X1 to X3 Image sensor head Y1 Reading device 1 Glass plate 1a Surface (of glass plate) 3,103 Light emitting element substrate 3a, 103a Upper surface of light emitting element substrate 3b Lower surface of light emitting element substrate 5 Light emitting element 5a, 105a Long Side 5b, 105b Short side 7 Light receiving element substrate 7a Upper surface 9 (light receiving element substrate) Upper surface 9 Light receiving element 11 Heat sink 11a Surface (of heat sink) 13 Frame member 13a Protruding portion 15 Lens holding member 17 Lens 19 Reflector 19a Reflecting surface 21 Diffusion plate 23 Reading medium 25, 27 Space 29 Heat radiating member 31 Reading surface 33 Drive unit

Claims (7)

A glass plate through which the reading medium passes along the surface;
A light emitting element substrate holding a light emitting element for irradiating the reading medium with light through the glass plate;
A light receiving element substrate holding a light receiving element that receives light reflected from the reading medium through the glass plate;
A radiator plate connected to the light emitting element substrate for radiating heat generated by the light emitting element, and
An image sensor head, wherein the heat radiating plate is disposed adjacent to the glass plate in the sub-scanning direction.   The image sensor head according to claim 1, wherein the light emitting element substrate is disposed on both sides of the glass plate in the sub-scanning direction, and the heat radiating plate is connected to each of the light emitting element substrates. A reflector is provided below the light emitting element substrate,
The image sensor according to claim 1, wherein light emitted from the light emitting element is reflected by the reflector, and the light reflected by the reflector is emitted to the reading medium via the glass plate. head. A frame member that holds the glass plate and the heat dissipation plate;
The image sensor head according to claim 1, wherein a height position of a surface of the glass plate is higher than a height position of a surface of the heat radiating plate. A plurality of the light emitting elements are arranged on the light emitting element substrate,
The light emitting element has a rectangular shape in plan view,
The light emitting element located at the center of the light emitting element substrate in the main scanning direction is arranged so that the long side is along the main scanning direction, and the light emitting element located at the end of the light emitting element substrate in the main scanning direction The image sensor head according to claim 1, wherein the short side is arranged along the main scanning direction.   The image sensor head according to claim 1, wherein a heat radiating member is disposed between the heat radiating plate and the light emitting element substrate. The image sensor head according to any one of claims 1 to 6,
And a drive unit that drives the image sensor head or the reading medium in a sub-scanning direction.

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