WO2013012066A1 - Lighting device, image sensor head and reading device provided with same - Google Patents

Abstract

[Problem] To provide a lighting device able to supply a uniform amount of light from a light guide member. [Solution] A lighting device (X1) is provided with: a light guide member (1) wherein multiple light guides (3a, 3b), which have light output sections (9a and 9b) that output light and reflecting sections (11a, 11b) that are disposed on the reverse side from the light output sections (9a, 9b), are connected at a connection section (8) such that the light output sections (9a, 9b) of the multiple light guides (3a, 3b) are continuous; and light-emitting members (7a, 7b) that are disposed at both ends of the light guide member (1) and provide light to the light guide member (1). Therein, a light absorption section (5) and/or a light diffusion section (10) is/are provided in the connection section (8), the reflecting sections (11a, 11b) in the vicinity of the connection section (8), and/or the light output sections (9a, 9b) in the vicinity of the connection section (8).

Description

[Replenishment based on Rule 26 20.08.2012] Illumination device, image sensor head, and reader equipped with the same

The present invention relates to an illumination device, an image sensor head, and a reading device including the same.

In recent years, there has been known an illuminating device that uniformly emits light from a light emitting member as a light source to a reading medium. This illuminating device supplies light from the light emitting member from one end of the light guide, reflects the light at the reflecting portion of the light guide, and emits the light reflected at the emitting portion. Light is emitted.

And the illuminating device provided with the light guide member formed by connecting two light guides in a connection part so that an output part may follow, and the light emission member arrange | positioned at the both ends of a light guide member is known. .

Also, a reading device such as a facsimile, an electronic blackboard, or a copying machine equipped with this illumination device is known. (For example, see Patent Document 1)

WO2006 / 104203 brochure

However, when two light guides are connected at the connection portion to form a light guide member and light is supplied to the light guide member from both ends by the light emitting member, part of the supplied light is reflected at the connection portion. There is a case. The light reflected by the connection part may be further reflected by the reflection part in the vicinity of the connection part. The light reflected by the reflection part is emitted from the emission part in the vicinity of the connection part, and the amount of light in the vicinity of the connection part may be larger than in other parts. Therefore, there is a possibility that a uniform amount of light cannot be supplied from the light guide member to the reading medium.

The illuminating device of the present invention includes a plurality of the light guides such that the emission parts in the plurality of light guides having an emission part that emits light and a reflection part disposed on the opposite side of the emission part are continuous. And a light emitting member that is disposed at both ends of the light guide member and supplies light to the light guide member. In addition, at least one of a light absorbing portion and a light diffusing portion is provided in at least one of the connecting portion, the reflecting portion in the vicinity of the connecting portion, and the emitting portion in the vicinity of the connecting portion.

Further, an image sensor head of the present invention is disposed apart from the illumination device described above, a plurality of light receiving elements, and the emission unit, and emits light emitted from the emission unit to a reading medium, A plurality of condensing units for condensing the light reflected from the reading medium.

Further, a reading apparatus 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 the transport direction.

According to the present invention, a uniform amount of light can be supplied from the light guide member to the reading medium.

It is a perspective view which shows the illuminating device which concerns on the 1st Embodiment of this invention. (A) is the II sectional view taken on the line shown in FIG. 1, (b) is a bottom view of an illuminating device. (A)-(c) is a conceptual diagram which shows the light radiate | emitted from a light guide member. FIG. 3A is a conceptual diagram in which light emitted from the light guide member shown in FIGS. 3A to 3C is synthesized, and FIG. 3B is a conceptual diagram showing light emitted from the illumination device shown in FIG. It is. The modification of the illuminating device shown in FIG. 1 is shown, (a) is a perspective view of a connection part vicinity, (b) is sectional drawing of the connection part vicinity. The other modification of the illuminating device shown in FIG. 1 is shown, (a) is sectional drawing of a connection part vicinity, (b) is a top view of the end surface of a light guide. It is a perspective view which shows the modification of the illuminating device shown in FIG. (A) is the II-II sectional view of the illuminating device shown in FIG. 7, (b) is explanatory drawing which expands and shows a light-diffusion part. It is a schematic perspective view which shows an image sensor head provided with the illuminating device shown in FIG. FIG. 10 is a schematic perspective view showing a reading device including the image sensor head shown in FIG. 9. It is a perspective view which shows the illuminating device which concerns on the 2nd Embodiment of this invention. (A) is a sectional view taken along line III-III shown in FIG. 11, and (b) is a bottom view of the illumination device. The modification of the illuminating device which concerns on the 2nd Embodiment of this invention is shown, (a) is sectional drawing corresponding to the III-III sectional view shown in FIG. 11, (b) is a bottom view of an illuminating device. is there. It is a conceptual diagram which shows the light radiate | emitted from an illuminating device, (a) shows the modification of the illuminating device shown in FIG. 11, (b) shows the other modification of the illuminating device shown in FIG. It is a perspective view which shows the illuminating device which concerns on the 3rd Embodiment of this invention. It is a schematic perspective view which shows an image sensor head provided with the illuminating device shown in FIG. It is a bottom view which shows roughly the relationship between a condensing part and the pattern of a prism. It is a schematic sectional drawing of the modification of the illuminating device shown in FIG.

<First Embodiment>
Hereinafter, a first embodiment according to the illumination device of the present invention will be described with reference to the drawings. As shown in FIG. 1, the illuminating device X1 includes a plurality of light guides 3a and 3b each having light emitting portions 9a and 9b that emit light and reflecting portions 11a and 11b that are arranged on the opposite sides of the light emitting portions 9a and 9b. The light guide member 1 is formed by connecting a plurality of light guides 3a and 3b at the connection portion 8 so that the light emitting portions 9a and 9b are continuous with each other. 1 is provided with light emitting members 7a and 7b for supplying light.

The light guide member 1 reflects the light supplied from the light emitting members 7a and 7b by the reflecting portions 11a and 11b and emits the light from the emitting portions 9a and 9b to the document table 2. In FIG. 1, the light emitted from the illumination device X <b> 1 and the region where the light reaches the document table 2 and is irradiated (irradiation area 4) are indicated by alternate long and short dash lines.

In the light guide member 1, the light emitting members 9 a and 9 b of the light guides 3 a and 3 b are continuous with the end surfaces 6 a and 6 b (see FIG. 2) of the two light guides 3 a and 3 b facing each other. Are connected by a connecting portion 8. The light guide member 1 is provided with light emitting members 7 at both ends of the light guide member 1 which are opposite surfaces of the connection portion 8 of the light guides 3a and 3b.

The light guides 3 a and 3 b have a function of emitting the light supplied from the light emitting member 7 to the irradiation area 4 of the document table 2. The light guides 3a and 3b reflect the incident light from the light emitting members 7a and 7b by the reflecting portions 11a and 11b located on the opposite side of the document table 2, and transmit the incident light to the original via the emitting portions 9a and 9b. Supply to stand 2. The light absorption part 5 for absorbing light is provided in the reflection parts 11a and 11b in the vicinity of the connection part 8 of the light guides 3a and 3b. In addition, the reflection parts 11a and 11b in the vicinity of the connection part 8 indicate the reflection parts 11a and 11b located at a predetermined distance from the connection part 8. The same applies to the emitting portions 9a and 9b in the vicinity of the connecting portion 8.

The vicinity of the connection portion 8 can be set to various values depending on the light amount of the light emitting member 7, the length of the light guide member 1, and the cross-sectional area of the connection portion 8. For example, the region in the vicinity of the connection portion 8 can be exemplified by a region whose length from the connection portion is 1 to 10% of the length of the light guide member 1. Specifically, in the case of the illuminating device X1 according to the first embodiment, an area of 2 to 5 mm from the connection portion 8 can be set in the vicinity of the connection portion 8, and the light absorption portion 5 may be provided in this range. . The distance from the connection part 8 can be suitably changed according to embodiment.

The illuminating device X1 has a configuration in which a distance D1 between one end portion of the light absorbing portion 5 and the connecting portion 8 is substantially equal to a distance D2 between the other end portion of the light absorbing portion 5 and the connecting portion 8. Yes. Here, the distance D1 between one end portion of the light absorbing portion 5 and the connecting portion 8 and the distance D2 between the other end portion of the light absorbing portion 5 and the connecting portion 8 are substantially equal to each other in manufacturing error. It is intended to include ranges and is not limited to being exactly the same.

The light emitting member 7 is a member for supplying light to the light guide member 1, and a light source such as an LED can be used. It is preferable that the light emitting members 7 disposed at both ends of the light guide member 1 have the same amount of light. Alternatively, one light emitting member 7a may be formed by the light source described above, and the other light emitting member 7b may be formed by a reflecting material such as a mirror.

The light guides 3a and 3b have an elongated cylindrical shape as shown in FIGS. The light guides 3a and 3b have emission portions 9a and 9b facing the document table 2, and reflection portions 11a and 11b arranged on the opposite side of the emission portions 9a and 9b. The site | part in which the reflection parts 11a and 11b of the light guides 3a and 3b are provided is provided on the plane formed in a cylindrical part. Therefore, the light reflected by the reflecting portions 11 a and 11 b can be emitted to the document table 2.

The light guides 3a and 3b are transmissive because it is necessary to reflect the light supplied by the light emitting members 7 disposed at both ends by the reflecting portions 11a and 11b and to emit the light from the emitting portions 9a and 9b. The transmittance T is preferably 85 to 98%. Examples of the material of the light transmissive (light transmissive) light guides 3a and 3b include organic materials such as glass, light transmissive ceramics, and acrylic resins.

The transmittance T represents the intensity of incident light and the intensity of transmitted light as a ratio, and can be obtained by an absorptiometric method or the like. For example, using a LED or the like as a light source, a predetermined light amount I ₀ is emitted from the light source to the measuring body. Then, the light quantity I emitted from the measuring body is measured by a light quantity measuring device such as an illuminometer, and the light quantity I is divided by the light quantity I ₀ to obtain the transmittance Τ.

The reflection portions 11a and 11b of the light guides 3a and 3b include a plurality of prisms 12 as shown in FIG. As shown in FIG. 2A, the plurality of prisms 12 have a triangular shape when viewed in cross section, and the prisms 12 have apexes located on the other side rather than the one side where the light emitting member 7 is provided. Is provided.

The prism 12 can be formed by processing the light guides 3 a and 3 b, and the height of the prism 12, the length of the prism 12, the interval between the prisms 12, or the inclination of the prism 12 is an aspect of the light guide member 1. Can be set as appropriate. In the illumination device X1, an example of the triangular prism 12 is shown, but the shape of the prism 12 may be cylindrical, trapezoidal, or rectangular.

In the light guides 3a and 3b, as shown in FIG. 2B, prisms 12 having the same size are formed at equal intervals. Further, the shape of the prism 12 is reversed between the light guide 3a and the light guide 3b. That is, it has a line-symmetric structure with the connecting portion 8 as a boundary. Therefore, a light guide having the same shape can be used for the light guide 3a and the light guide 3b, and the light guide member 1 can be easily manufactured. That is, the same light guides 3a and 3b can be used for the light guide 3a and the light guide 3b, and the light guide member 1 is produced by connecting the end faces 6a and 6b of the light guides 3a and 3b. can do.

As shown in FIG. 2 (a), the light guide member 1 is provided with a light absorption part 5 in the reflection parts 11a and 11b in the vicinity of the connection part 8 of the light guides 3a and 3b. The light absorption part 5 is provided on the two prisms 12 on the connection part 8 side in the reflection part 11a of the light guides 3a and 3b. Therefore, the light guide member 1 has a configuration in which the light absorption part 5 is provided on the four prisms 12 in the vicinity of the connection part 8 of the light guides 3a and 3b.

The light absorbing part 5 has a function of absorbing light, and a black film is formed by applying a black paint. Examples of the light absorbing part 5 include oil-based paints, one-part room temperature thermosetting adhesives, one-part moisture curable elastic adhesives, and the like. The thing with a low reflectance is preferable from the point of the function which absorbs light. Therefore, it is preferable to use dark colors for these colors, and it is particularly preferable to use black ones.

Further, the light absorption part 5 may be formed by applying the material forming the light absorption part 5 to the entire surface, or may be formed by applying it in a mesh shape. Thereby, the light absorption amount by a light absorption part can be adjusted. Furthermore, it may be applied in a pattern such as a slit. Even in this case, the amount of light absorbed by the light-absorbing part can be adjusted.

The reflectance indicates the ratio of the reflected light intensity to the incident light intensity when the light is reflected on the surface of the material. If the incident light flux Φ and the reflected light flux Φr are represented, the reflectance R can be expressed as Φr / Φ. it can. The reflectance can be measured by using the diffuse reflection method. In order to reduce the amount of light in the vicinity of the connecting portion 8, the reflectance of the light absorbing portion 5 is preferably 1 to 20%.

Next, the light reflected by the reflecting portions 11a and 11b will be described with reference to FIGS. 3 and 4 are shown with hatching omitted.

As shown in FIG. 3A, a part of the light supplied from the light emitting member 7a on the light guide 3a side is reflected by the prism 12 of the reflecting portion 11a, and is sent to the document table 2 through the emitting portion 9a. Light is emitted. Similarly, the light supplied from the light emitting member 7b on the light guide 3b side is reflected by the prism 12 of the reflecting portion 11b, and the light is emitted to the document table 2 through the emitting portion 9b. Hereinafter, this reflection may be referred to as normal reflection.

Also, as shown in FIG. 3B, a part of the light supplied from the light emitting member 7a on the light guide 3a side passes through the connecting portion 8 and enters the adjacent light guide 3b to be guided. The light is reflected by the reflecting portion 11b of the light body 3b, and light is emitted to the document table 2 through the emitting portion 9b. Similarly, part of the light supplied from the light emitting member 7b on the light guide 3b side passes through the connecting portion 8 and enters the adjacent light guide 3a, and is reflected by the reflecting portion 11a of the light guide 3a. Then, light is emitted to the document table 2 through the emission unit 9a. Hereinafter, this reflection may be referred to as transmission reflection.

Further, as shown in FIG. 3C, a part of the light supplied from the light emitting member 7a on the light guide 3a side is reflected by the connecting portion 8 and reflected by the reflecting portion 11a of the light guide 3a. Thus, light is emitted to the document table 2 through the emission unit 9a. Similarly, a part of the light supplied from the light emitting member 7b on the light guide 3b side is reflected by the connecting portion 8, reflected by the reflecting portion 11b of the light guide 3b, and the original through the emitting portion 9b. Light is emitted to the table 2. Hereinafter, this reflection may be referred to as connection reflection.

In the illumination device X1 formed by connecting the light guides 3a and 3b, the amount of light supplied to the document table 2 is larger in the vicinity of the connection portion 8 than in other regions due to the above-described transmission reflection and connection reflection. There is a possibility.

FIG. 4A is a conceptual diagram in which the reflection of light shown in FIGS. 3A to 3C is combined. FIG. 4B is a light guide in which a light absorbing portion 5 is provided in the vicinity of the connecting portion 8. FIG. 3 is a conceptual diagram showing light emission from a member 1. As shown in FIG. 4A, in the vicinity of the connection portion 8, the reflection portion 11 a of the light guide 3 a has the light that has passed through the light guide 3 a, the light that has passed through the light guide 3 b, and the connection portion 8. The light reflected at is reflected. Similarly, in the vicinity of the connection part 8, the reflection part 11b of the light guide 3b receives the light that has passed through the light guide 3b, the light that has passed through the light guide 3a, and the light reflected by the connection part 8. reflect.

In the illumination device X1, the light absorption unit 5 is provided in the reflection units 11a and 11b in the vicinity of the connection unit 8 of the light guide member 1. Therefore, as shown in FIG. 4B, the light supplied to the reflecting portions 11a and 11b is absorbed by the light absorbing portion 5, and the light is not reflected from the prism 12 provided with the light absorbing portion 5 to the document table. It becomes. That is, a part of the light supplied to the reflecting portions 11a and 11b is absorbed by the light absorbing portion 5 and reflected as shown by a one-dot chain line is not supplied to the document table.

Thereby, the amount of light emitted from the vicinity of the connection portion 8 can be reduced, and the amount of light supplied to the document table 2 in the vicinity of the connection portion 8 can be reduced. Therefore, a uniform amount of light can be supplied from the light guide member 1 to the document table 2.

In addition, the light guide member 1 includes the other end (end surface 6a) of the light guide 9a having the light emitting member 7 connected to one end thereof, and the other end of the light guide 9b having the light emitting member 7 connected to one end thereof. Since the (end surface 6b) is connected by the connection part 8, the large light guide member 1 can be produced by combining the light guide 1. In addition, it is preferable to mirror-finish the end surfaces 6a and 6b of the light guide members 9a and 9b connected by the connecting portion 8. By mirror-finishing the connecting portion 8, reflection at the connecting portion 8 can be reduced.

Furthermore, the distance D1 between one end of the light absorbing portion 5 and the connecting portion 8 is substantially equal to the distance D2 between the other end of the light absorbing portion 5 and the connecting portion 8. In other words, the light guide member 1 is axisymmetrically configured with the connection portion 8 as a boundary. Therefore, the amount of light emitted from the light guide 3a and the light guide 3b can be made closer to each other. Thereby, a uniform amount of light can be emitted in the arrangement direction of the prisms 12.

A modification of the illumination device X1 will be described with reference to FIGS.

In the illumination device X1 ′ shown in FIG. 5, the light absorption unit 5 is provided in the emission units 9a and 9b in the vicinity of the connection unit 8. The other points are the same as those of the illumination device X1, and the description thereof is omitted.

The light absorption part 5 is provided in the emission parts 9 a and 9 b in the vicinity of the connection part 8. As a result, the amount of light emitted from the emitting portions 9 a and 9 b near the connection portion 8 can be reduced, and a uniform amount of light can be supplied to the document table 2.

In the illuminating device X1 ″ shown in FIG. 6, the light absorption part 5 is provided in the connection part 8, and a part of the reflected light reflected by the connection part 8 is absorbed. Further, a part of the transmitted light that passes through the connection portion 8 is absorbed. Thereby, transmission reflection and connection reflection can be reduced, and the emitted light in the vicinity of the connection part 8 can be reduced. Therefore, a uniform amount of light can be supplied to the document table 2.

As shown in FIG. 6B, the light absorber 5 is provided at the lower part of the end face 6a of the light guide 3a. In addition, you may provide the light absorption part 5 also in the end surface 6b of the corresponding light guide 3b. As described above, the light absorption part can be provided by applying an oil-based paint or the like to the end face 6a, but it may be applied so that slits are provided in the horizontal direction or the vertical direction. In that case, the transmitted light can be diffracted by the slit to scatter the transmitted light. Thereby, the transmission reflection in the vicinity of the connection part 8 can be reduced. In addition, although the example provided in the lower part of the end surface 6a of the light guide 3a was shown, you may provide the light absorption part 5 in the upper part of the end surface 6a.

In the first embodiment, the light absorption unit 5 is provided separately in the connection unit 8, the emission units 9 a and 9 b in the vicinity of the connection unit 8, or the reflection units 11 a and 11 b in the vicinity of the connection unit 8, respectively. However, the present invention is not limited to this.

For example, the light absorption unit 5 may be provided in the emission units 9a and 9b in the vicinity of the connection unit 8 and the reflection units 11a and 11b in the vicinity of the connection unit 8. Moreover, you may provide the light absorption part 5 in the emission part 9a, 9b in the vicinity of the connection part 8 and the connection part 8. FIG. Moreover, you may provide the light absorption part 5 in the reflection part 11a, 11b in the vicinity of the connection part 8 and the connection part 8. FIG. Furthermore, the light absorbing portion 5 may be provided in all of the connecting portion 8, the emitting portions 9 a and 9 b in the vicinity of the connecting portion 8, and the reflecting portions 11 a and 11 b in the vicinity of the connecting portion 8.

An illumination device X1 '' '' that is a modification of the illumination device X1 will be described with reference to FIGS. In the illuminating device X <b> 1 ″ ″, the light diffusion unit 10 is provided in the reflection units 11 a and 11 b in the vicinity of the connection unit 8.

The light diffusion unit 10 has a function of diffusing the light incident on the light diffusion unit 10. As shown in FIG. 8B, the light diffusing portion 10 is exemplified by a light diffusing member in which a dot pattern is formed on the surface as a first concavo-convex portion or a light diffusing member formed by a slid material. Can do. The light diffusing portion 10 is formed by adhering the light diffusing member to the reflecting portions 11a and 11b in the vicinity of the connecting portion 8 with a bonding member such as a double-sided tape or an adhesive. The dot pattern is a member in which dots provided as convex portions are arranged in a predetermined repeating pattern.

The first concavo-convex portion shows a hemispherical dot in FIG. 8B, but the shape of the dot may be a conical shape, a cubic shape, or a cylindrical shape. Further, the repeating pattern may be a row instead of a staggered pattern. As the light diffusing unit 10, instead of adhering a light diffusing member, the light diffusing unit 10 may be provided by providing a dot pattern or a plurality of grooves on the reflecting units 11a and 11b. Moreover, you may make the reflection parts 11a and 11b contain light-diffusion particles, such as a pigment or a metal particle.

With the above configuration, the light emitted to the light diffusion unit 10 is diffused by the light diffusion unit 10 and the light is scattered. Thereby, by providing the light diffusion part 10 in the vicinity of the connection part 8, the amount of light emitted in the vicinity of the connection part 8 can be reduced.

The image sensor head Y1 provided with the illumination device X1 and the reading device Z1 provided with the image sensor head Y1 will be described with reference to FIGS.

The image sensor head Y1 includes a light guide member 1 constituting the illumination device X1, a light emitting member provided at both ends of the light guide member 1, which is omitted in FIG. 9, a plurality of light receiving elements 16, and a plurality of light receiving elements 16. The condensing unit 18 in which lenses are arranged is housed in a frame 20 and configured. The upper surface of the frame 20 is covered with a cover glass 17.

A plurality of light receiving elements 16 are arranged on one straight line that is the main scanning direction, and are connected to the input terminals of the switching elements. The light receiving element 16 has a function of flowing current when irradiated with light. For example, a photoelectric conversion element formed of a thin film photodiode can be used.

Between the light receiving element 16 and a reading medium (not shown) to be read, a condensing unit 18 in which a plurality of lenses corresponding to the light receiving element 16 are arranged is disposed. That is, a plurality of light collecting portions 18 are also arranged in a straight line that is the main scanning direction. The condensing unit 18 is a member for supplying the light receiving element 16 with reflected light generated by the light emitted from the light guide member 1 to the reading medium being reflected by the reading medium. A lens can be used as the condensing unit 18.

The cover glass 17 is fixed to the frame body 20 and has a function of holding a reading medium arranged on the upper surface of the cover glass. Moreover, it has the function to protect each member provided in the inside of the frame 20. The cover glass 17 needs to have transparency to allow the light supplied from the light guide member 1 to reach the reading medium.

The frame 20 is a housing for housing the light guide member 1, the light receiving element 16, and the light collector 18, and is made of plastic or the like. The frame body 20 has a function of holding the light receiving element 16 and the light collecting unit 18 at a predetermined interval.

The image sensor head Y1 has a function of emitting light to the reading medium by the irradiation device X1 and reading the reflected light reflected by the reading medium by the light receiving element 16 via the light collecting unit 18. That is, it has a function of converting image information of the reading medium into an electric signal. The image sensor head Y1 is incorporated in a reading device Z1 further including a drive unit 22 (see FIG. 10) that drives the frame 20 in the sub-scanning direction and a control unit (not shown) that controls driving. A reading device Z1 such as a fax machine, a scanner, or a combination of these or an electronic blackboard can be used.

The reading device Z1 including the image sensor head Y1 will be described with reference to FIG. 10 using an electronic blackboard as an example.

The reading device Z1 includes an image sensor head Y1 and a drive unit 22 that drives the image sensor head Y1 in the sub-scanning direction that is the reading direction.

The surface of the cover glass 17 of the image sensor head Y1 and the reading surface 23 of the reading device Z1 are arranged so as to face each other, and the drive unit 22 is connected to the upper part of the image sensor head Y1.

The drive unit 22 is provided such that the image sensor head Y1 moves in the sub-scanning direction on the reading surface 23 of the reading device Z1. The drive unit 22 has wheels (not shown) arranged on guide rails (not shown) of the reading device Z1, and drives a drive mechanism (not shown) such as a motor to thereby drive an image sensor on the reading surface 23. The head Y1 can be moved in the sub-scanning direction. The drive unit 22 may be provided inside the image sensor head Y1.

When reading an image or the like written on the reading surface 23, the reading device Z1 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 drive unit 22 to read the pixels adjacent to the read one line, and operates the drive unit 22 so that the reading device Z1 moves on the guide rail by one pixel. Let The reading device Z1 reads a reading medium 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 the reader Z1, this technique may be used for a multifunction device or the like. In that case, the image sensor head Y1 is fixed to the multifunction peripheral, and the drive unit 22 drives the reading medium in the transport direction, which is the main scanning direction, to read the reading medium. Further, although the image sensor head Y1 including the cover glass 17 has been illustrated, the image sensor head Y1 may not include the cover glass 17.

<Second Embodiment>
The illumination device X2 will be described with reference to FIGS. In the illumination device X2, the light diffusion portion 10 is provided in the reflection portions 11a and 11b in the vicinity of the connection portion 8, and the adhesive 13 is disposed as the connection portion 8 between the light guide 3a and the light guide 3b. The light guide 3 a and the light guide 3 b are connected by an adhesive 13. As shown in FIG. 12, the distance between the prisms 12 (hereinafter referred to as the prism pitch) becomes narrower from the end of the light guide member 1 toward the connection portion 8. Therefore, the prism pitch is shorter on the connection portion 8 side than on the light emitting member 7 side. Other configurations are the same as those of the illumination device X1.

The adhesive 13 may be an acrylic silicone resin. Further, the one-component room temperature thermosetting adhesive described above or the one-component moisture curable elastic adhesive can be used.

The transmittance T of the adhesive 13 is preferably 75 to 96% in terms of transmittance, and is equal to or lower than the transmittance T of the light guides 3a and 3b. preferable. By making the transmittance T of the adhesive 13 equal to the transmittance T of the light guides 3a and 3b, reflection is less likely to occur at the connection portion 8, and connection reflection can be reduced. The amount of light emitted from the vicinity can be reduced.

In addition, by making the transmittance of the adhesive 13 lower than the transmittance of the light guides 3a and 3b, reflection hardly occurs at the connection portion 8, and the amount of light emitted from the vicinity of the connection portion 8 can be reduced. .

The prism pitch becomes narrower as it goes from the end of the light guide member 1 toward the connecting portion 8. That is, as shown in FIG. 12, the connecting portion 8 side is shorter than the light emitting member 7 side. In the illumination device X2, the prism pitch L1 is 0.6 to 1.0 mm on the light emitting member 7 side, and the prism pitch L2 is 0.1 to 0.6 mm on the connection portion 8 side. And the illuminating device X2 is comprised so that a prism pitch may become short gradually toward the connection part 8 side from the light emission member 7 side.

In this manner, the prism pitch L2 on the connection portion 8 side is formed to be shorter than the prism pitch L1 on the light emitting member 7 side, so that the connection portion 8 is also located on the connection portion 8 side far from the light emitting member 7. The amount of light on the side can be secured.

Here, the lighting device may generate heat during operation, and when the both ends of the light guide member are fixed, the light guide body thermally expands, causing stress at the connection portion between the light guide bodies. The light guide may be warped. When the light guide body is warped in this way, the light exit surface of the light guide member is distorted, and the brightness unevenness of the illumination light of the lighting device may be generated, or the average brightness may be lowered.

In addition, for example, when a reading device for an electronic blackboard is formed using an illuminating device, the illuminating device may be operated in a state of standing in the weight direction, and in this case, stress is concentrated on the connection portion. The light guide body may be deformed.

On the other hand, since the illuminating device X2 uses the adhesive 13 as the connection portion 8, it can relieve the thermal expansion of the light guides 3a and 3b, and even when both ends are fixed, Warpage of the light guides 3a and 3b can be suppressed. Thereby, generation | occurrence | production of the distortion of the light-projection surface of the light guide member 1 can be suppressed, and the brightness nonuniformity of an illuminating device or the fall of average brightness | luminance can be reduced.

Further, the lighting device X2 is firmly fixed to the frame with the light guide body 3a positioned below by screwing or the like, and the light guide body 3a and the light guide body 3b are connected by the adhesive 13, and the light guide body 3a is positioned upward. By fixing the light guide 3b to the frame with the adhesive 13, the lighting device X2 has the lower light guide 3a firmly fixed and the upper light guide 3b fixed deformably. Become. Thereby, even when the light guides 3a and 3b are thermally expanded, the light guide member 1 can extend upward, and the warpage of the light guide member 1 can be suppressed.

It is more preferable to use an elastic adhesive having elasticity as the adhesive 13. By using an elastic adhesive having elasticity, the stress caused by the thermal expansion of the light guides 3a and 3b can be further relaxed. In addition, the stress caused by the weight of the light guides 3a and 3b can be relaxed.

Furthermore, since the light guide 3a and the light guide 3b are connected by the adhesive 13, the reliability can be improved even when a humidity change occurs as well as a temperature change.

In addition, although the example in which the prism pitch is gradually reduced from the light emitting member 7 side toward the connecting portion 8 side is shown, the prism pitch L2 on the connecting portion 8 side is larger than the prism pitch L1 on the light emitting member 7 side. You may comprise so that it may become short in steps.

A modification of the illumination device X2 according to the second embodiment will be described with reference to FIG. In the illumination device X <b> 2 ′, the length of the prism 12 becomes shorter from the end of the light guide member 1 toward the connection portion 8. That is, the length L4 of the prism 12 located on the connection portion 8 side in the arrangement direction of the prism 12 is shorter than the length L3 of the prism 12 located on the light emitting member 7 side in the arrangement direction of the prism 12. Yes. The adhesive 13 contains light diffusing particles, and the adhesive 13 functions as the light diffusing portion 10. Other configurations are the same as those of the illumination device X2, and the description thereof is omitted.

In the illumination device X2 ′, since the length of the prism 12 is shortened from the end of the light guide member 1 toward the connection portion 8, reading is performed even on the connection portion 8 side that is far from the light emitting member 7. The amount of light emitted to the medium can be secured.

The length of the prism 12 can be, for example, the prism length L3 on the light emitting member 7 side is 0.4 mm, and the prism length L4 on the connection portion 8 side is 0.2 mm. These values may be appropriately set according to the embodiment.

Also, the prism pitch and the prism length of the light emitting member 7 side and the connecting portion 8 side may be changed by combining the lighting device X2 and the lighting device X2 ′. That is, the prism pitch L2 on the connecting portion 8 side is made shorter than the prism pitch L1 on the light emitting member 7 side, and the prism length L4 on the connecting portion 8 side is compared with the prism length L3 on the light emitting member 7 side. By making the length shorter, it is possible to further secure the amount of light emitted to the reading medium on the connection portion 8 side.

The adhesive 13 contains 1.0 to 10.0% by weight of calcium carbonate as light diffusion particles inside. In addition, instead of calcium carbonate, titanium oxide or milky white pigment may be contained as light diffusing particles.

Since the adhesive 13 functions as the light diffusing unit 10, transmission reflection and connection reflection can be reduced, and the amount of light in the vicinity of the connection unit 8 can be reduced. Moreover, since the light diffusing part 10 is formed by containing the light diffusing particles in the adhesive 10, the light diffusing part 10 can be easily formed in the illumination device X2 ′.

A modification of the light diffusing unit 10 will be described with reference to FIG.

The illuminating device X2 ″ shown in FIG. 14A includes a light diffusing portion 10 instead of the adhesive 13, and the light diffusing particles are arranged on the prism 12 located closest to the connecting portion 8 among the prisms 12. Is contained and functions as the light diffusion portion 10. Other points are the same as those of the illumination device X2.

The light diffusing unit 10 disposed between the end faces 6a and 6b of the light guides 3a and 3b is made to be opaque by being rubbed on both surfaces of a transparent member such as acrylic. The end surfaces 6a and 6b of the light guides 3a and 3b are respectively mirror-finished, and the end surfaces 6a and 6b of the light guides 3a and 3b are in contact with the light diffusing unit 10, respectively. Thereby, possibility that reflection will arise in the boundary of the light-diffusion part 10 and end surface 6a, 6b of light guide 3a, 3b can be reduced. Thereby, connection reflection can be reduced.

In addition, the prism 12 located on the side closest to the connection portion 8 functions as the light diffusion portion 10. Therefore, normal reflection, transmission reflection, and connection reflection in the vicinity of the connection portion 8 can be reduced, and the amount of light emitted from the vicinity of the connection portion 8 can be reduced.

In the illuminating device X2 ″ ″ shown in FIG. 14 (b), second uneven portions are provided on the end surfaces 6a and 6b of the light guides 3a and 3b. The end surfaces 6a and 6b of the light guides 3a and 3b are surface-treated by a sandblasting method or the like to form second uneven portions. An adhesive 13 is provided between the end faces 6a and 6b of the light guides 3a and 3b, and connects the light guides 3a and 3b.

As described above, since the second concavo-convex portions are formed on the end surfaces 6a and 6b of the light guides 3a and 3b, light can be diffused on the end surfaces 6a and 6b of the light guides 3a and 3b. The end faces 6a and 6b of the light bodies 3a and 3b function as the light diffusion portion 10. Therefore, the light reflected by the end surfaces 6a and 6b of the light guides 3a and 3b can be reduced. Moreover, since the uneven | corrugated | grooved part is provided in the end surfaces 6a and 6b of the light guides 3a and 3b, the adhesive agent 13 penetrates into the 2nd uneven | corrugated | grooved part, and improves the connection strength of the light guides 3a and 3b. be able to. In addition, you may form a 2nd uneven | corrugated | grooved part with the member similar to a 1st uneven | corrugated | grooved part.

Note that the interval between the prisms 12 means the prism pitch, and means the intervals L1 and L2 between the apexes of the adjacent prisms 12 as shown in FIG. The length of the prism 12 indicates the lengths L3 and L4 of one prism 12, as shown in FIG. The height of the prism 12 indicates the height of the prism 12 protruding from the reflecting portions 11a and 11b. Furthermore, the inclination of the prism 12 means the inclination of the slope constituting the prism 12 when the triangular prism 12 is used.

In the illumination device X2, the example in which the light diffusion portion 10 is provided below the reflection portions 11a and 11b in the vicinity of the connection portion 8 and below the adhesive 13 is shown, but the present invention is not limited to this. . For example, the light diffusion unit 10 may be provided in the emission units 9 a and 9 b in the vicinity of the connection unit 8. Further, the light diffusing unit 10 may be provided in the connection unit 8 and the emission units 9 a and 9 b in the vicinity of the connection unit 8. In addition, the light diffusing unit 10 may be provided in the connection unit 8 and the reflection units 11 a and 11 b in the vicinity of the connection unit 8. Further, the light diffusing unit 10 may be provided in the emission units 9 a and 9 b in the vicinity of the connection unit 8 and the reflection units 11 a and 11 b in the vicinity of the connection unit 8. Furthermore, the light diffusing unit 10 may be provided in all of the connection unit 8, the emission units 9 a and 9 b in the vicinity of the connection unit 8, and the reflection units 11 a and 11 b in the vicinity of the connection unit 8.

<Third Embodiment>
The illumination device X3 will be described with reference to FIGS. In the illuminating device X3, the light absorbing portion 5 is provided in the reflecting portions 11a and 11b in the vicinity of the connecting portion 8, and the connecting portion 8 is coated with the adhesive 13 containing light diffusing particles. It is functioning.

The condensing part 18 has a central part and an edge located outside the central part, and has a function of condensing light. The condensing unit 18 can use a generally known lens or the like. The central portion of the light collecting portion 18 indicates an area of about 70 to 85% from the center of the light collecting portion 18, and the end portion of the light collecting portion 18 indicates other portions.

FIG. 16 is a perspective view schematically showing an image sensor head Y2 including the illumination device X3. The image sensor head Y2 reads the image data of the reading medium P by irradiating the reading medium P with light and reading the reflected light from the reading medium P. More specifically, light is emitted from the light guide member 1 toward the reading medium P. The light emitted to the reading medium P is reflected by the reading medium P. The light reflected by the reading medium P is collected by a plurality of light collecting units 18 and supplied to the light receiving elements 16 corresponding to the light collecting units 18. The plurality of light receiving elements 16 read reflected light from the reading medium P and convert image information on the reading medium P into electronic data.

Here, in the light collecting part, there may be a difference in the amount of light collected between the central part and the edge part of the light collecting part. Specifically, the light collecting unit may cause a difference in light amount due to a decrease in peripheral light amount between the central part and the edge part of the light collecting part, and compared with the central part of the light collecting part at the edge part of the light collecting part. May reduce the amount of light. Therefore, there is a possibility that the amount of light supplied to the light receiving element varies.

However, the illumination device X3 illustrated in FIG. 17 has a configuration in which the interval between the prisms 12 corresponding to the edge of the light collecting unit 18 is smaller than the interval between the prisms 12 corresponding to the central portion of the light collecting unit 18. Yes. In other words, the number of the prisms 12 existing in the region of the reflecting portions 11 a and 11 b corresponding to the edge of the light collecting portion 18 is equal to the number of the prisms 12 existing in the region of the reflecting portions 11 a and 11 b corresponding to the central portion of the light collecting portion 18. More than the number of the configuration.

Therefore, the amount of light reflected by the reflecting portions 11 a and 11 b corresponding to the edge of the light collecting portion 18 is larger than the amount of light reflected by the reflecting portions 11 a and 11 b corresponding to the central portion of the light collecting portion 18. Therefore, the amount of light supplied to the edge of the light collecting unit 18 is larger than the amount of light supplied to the central part of the light collecting unit 18, and variations in the amount of light supplied to the light receiving element 16 can be reduced. .

Further, by providing the light absorbing portion 5 in the reflecting portions 11a and 11b and providing the light diffusing portion 10 in the connecting portion 8, the transmitted light and the reflected light at the connecting portion 8 can be reduced, and the reflecting portions 11a and 11b. The light-absorbing part 5 provided in the can further reduce transmission reflection and connection reflection. For this reason, the amount of light in the vicinity of the connection portion 8 can be reduced.

It should be noted that the prism 12 corresponding to the edge of the light collecting unit 18 means the prism 12 present at a position where light is supplied to the edge of the light collecting unit 18. The regions of the reflecting portions 11 a and 11 b corresponding to the edge of the light collecting portion 18 mean regions of the reflecting portions 11 a and 11 b that exist at positions where light is supplied to the edge of the light collecting portion 18. The prism 12 corresponding to the central portion of the light collecting portion 18 means the prism 12 present at a position where light is supplied to the central portion of the light collecting portion 18. Further, the regions of the reflecting portions 11 a and 11 b corresponding to the central portion of the light collecting portion 18 mean regions of the reflecting portions 11 a and 11 b that exist at positions where light is supplied to the central portion of the light collecting portion 18.

That is, the reflected light reflected by the prism 12 located in the region of the reflecting portions 11a and 11b corresponding to the edge of the light collecting portion 18 is irradiated to the reading medium P, and the reflected light reflected by the reading medium P is Then, the light is supplied to the end of the light collecting unit 18. The same applies to the central portion of the light collecting portion 18. These correspondences can be obtained by simulation, for example. Specifically, a region in which various dimensions of the light guide member 1, position information of the light converging unit 18, and information such as the shape of the prism 12 are input to the calculation unit, and the light reflected by the prism 12 is irradiated onto the light converging unit 18. Can be requested. Therefore, the correspondence relationship between the reflected light of the prism 12 and the light collecting unit 18 can be obtained.

In the illumination device X3, the example in which the interval between the prisms 12 corresponding to the edge of the light collecting unit 18 is made smaller than the interval between the prisms 12 corresponding to the central portion of the light collecting unit 18 is shown. The length may be changed. That is, the length of the prism 12 in the region of the reflecting portions 11 a and 11 b corresponding to the edge of the light collecting portion 18 is greater than the length of the prism 12 in the region of the reflecting portions 11 a and 11 b corresponding to the central portion of the light collecting portion 18. Also, a long configuration may be used. Even in this case, the amount of light supplied to the edge of the light collecting unit 18 can be increased, and variations in the amount of light supplied to the light receiving element 16 can be reduced.

Referring to FIG. 18, an illumination device X3 ′, which is a modification of the illumination device X3, will be described. In the illumination device X3 ′, the prism 12 has a first surface 14a and a second surface 14b located on the side farther from the connecting portion 8 than the first surface 14a in a cross-sectional view. The triangular shape is comprised by 14a and the 2nd surface 14b, and the light absorption part 5 is provided in the 2nd surface 14b.

Thus, since the light absorption part 5 is provided on the second surface 14b of the prism 12, it is possible to reduce transmission reflection and connection reflection. That is, the prism 12 does not reduce the normal reflection by the first surface 14a, but can absorb the transmission reflection and the connection reflection that cause an increase in the amount of light of the connection portion 8 by the light absorption portion 5 provided on the second surface 14b. Therefore, the amount of light in the vicinity of the connection portion 8 can be reduced. In addition, although the example which provided the light absorption part 5 in the 2nd surface 14b of the prism 12 was shown, you may provide the light-diffusion part 10. FIG.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. The embodiments X1 to X3 may be arbitrarily combined.

For example, the shape of the prism 12 in the reflecting portions 11a and 11b may be different depending on the position. For example, the amount of light in the vicinity of the connection portion 8 can be increased by making the height of the prism on the connection portion 8 side higher than the height of the prism 12 on the light emitting member 7 side.

Further, although the light guide member 1 in which two light guides 3a and 3b are combined is illustrated, the light guide member 1 may be formed by combining two or more light guides 3a and 3b.

Furthermore, the light diffusing unit 10 may be provided in all parts of the emitting units 9a and 9b, the reflecting units 11a and 11b, and the connecting unit 8, and all of the emitting units 9a and 9b, the reflecting units 11a and 11b, and the connecting unit 8 are provided. You may provide the light absorption part 5 in this site | part. Further, the light diffusing unit 10 and the light absorbing unit 5 may be combined and used simultaneously. Preferably, it is preferable to provide the light diffusing unit 10 in the emitting units 9a and 9b and the connecting unit 8 and provide the light absorbing unit 5 in the reflecting units 11a and 11b. Thereby, while suppressing the fall of the whole light quantity radiate | emitted from the light guide member 1, the light quantity of the vicinity of the connection part 5 can be reduced, and a uniform light quantity can be supplied from the light guide member 1. FIG.

In addition, although the example of the reading device Z1 provided with the image sensor head Y1 using the illumination device X1 has been described, a reading device Z1 that employs the image sensor head Y2 may be configured instead of the image sensor head Y1.

X1 to X3 Illumination device Y1, Y2 Image sensor head Z1 Reading device 1 Light guide member 3a, 3b Light guide 5 Absorbing portion 6a, 6b End surface 7a, 7b Light emitting member 8 Connection portion 9a, 9b Emitting portion 10 Light diffusion portion 11a, 11b Reflector 12 Prism 13 Adhesive 14a First surface 14b Second surface 16 Light receiving element 18 Condenser 20 Frame

Claims (14)

A plurality of the light guides are connected at a connection portion so that the light emission portions in a plurality of light guides having an emission portion that emits light and a reflection portion arranged on the opposite side of the emission portion are continuous. A light guide member,
A light emitting member that is disposed at both ends of the light guide member and supplies light to the light guide member,
At least one of a light absorption part and a light diffusion part is provided in at least one of the connection part, the reflection part in the vicinity of the connection part, and the emission part in the vicinity of the connection part. apparatus. The reflecting portion includes a plurality of prisms,
The lighting device according to claim 1, wherein the light absorption unit or the light diffusion unit is provided on the prism located closest to the connection unit among the plurality of prisms. The prism has a first surface and a second surface located on a side farther from the connecting portion than the first surface in a cross-sectional view, and the first surface and the second surface are triangular. Make up the shape,
The lighting device according to claim 2, wherein the light absorption unit or the light diffusion unit is provided on the second surface. The lighting device according to claim 3, wherein the light absorption part is formed of a black film. The prism located on the side closest to the connecting portion among the plurality of prisms contains light diffusing particles,
The lighting device according to claim 2, wherein the prism containing the light diffusion particles functions as the light diffusion portion. The reflecting portion includes a plurality of prisms,
A first convex concave portion is provided in a portion of the light guide other than the plurality of prisms,
The first convex concave portion is located in at least one of the reflecting portion in the vicinity of the connecting portion and the emitting portion in the vicinity of the connecting portion, and functions as the light diffusing portion. The lighting device described. The connection portion contains light diffusing particles,
The lighting device according to claim 1, wherein the connection portion containing the light diffusion particles functions as the light diffusion portion. The lighting device according to any one of claims 1 to 7, wherein the light guide has a second convex concave portion on an end face connected by the connection portion. The reflecting portion includes a plurality of prisms,
The lighting device according to claim 1, wherein an interval between the prisms is narrowed from an end of the light guide member toward the connecting portion. The reflecting portion includes a plurality of prisms,
The lighting device according to claim 1, wherein a length of the prism is shortened from an end portion of the light guide member toward the connection portion. A lighting device according to claim 1;
A plurality of condensing units that are arranged apart from the emitting unit, emit the light emitted from the emitting unit to a reading medium, and collect the light reflected from the reading medium;
An image sensor head comprising: a plurality of light receiving elements that receive light collected by the plurality of light collecting units. The reflecting portion of the lighting device includes a plurality of prisms;
The condensing part has a central part and an edge located outside the central part,
A plurality of the prisms are disposed in the region of the reflecting portion corresponding to the edge of the light collecting portion, and a plurality of the prisms are also disposed in the region of the reflecting portion corresponding to the central portion of the light collecting portion. And
The spacing between the prisms in the region of the reflecting portion corresponding to the edge of the light collecting portion is smaller than the spacing between the prisms in the region of the reflecting portion corresponding to the central portion of the light collecting portion, The image sensor head according to claim 11. The reflecting portion of the lighting device includes a plurality of prisms;
The condensing part has a central part and an edge part located outside the central part,
A plurality of the prisms are disposed in the region of the reflecting portion corresponding to the edge of the light collecting portion, and a plurality of the prisms are also disposed in the region of the reflecting portion corresponding to the central portion of the light collecting portion. And
The length of the prism in the region of the reflecting portion corresponding to the edge portion of the light collecting portion is longer than the length of the prism in the region of the reflecting portion corresponding to the central portion of the light collecting portion. The image sensor head described in 1. An image sensor head according to claim 11,
And a drive unit that drives the image sensor head or the reading medium in a transport direction.

Images