JP5820156B2 - Illumination apparatus and image reading apparatus using the illumination apparatus - Google Patents

Description

The present invention relates to an illuminating device including a light guide as a linear light source that is most suitable for an image reading device such as a scanner device, a copying machine, or a facsimile.

In general, as an image reading apparatus of this type, as disclosed in, for example, Japanese Patent Application Laid-Open No. H10-294707, an image is read by irradiating a document conveyed on a reading platen with light received by a photoelectric conversion sensor. Readers are known.

The illumination device of the image reading device disclosed in Patent Document 1 includes an LED light emitter serving as a light source and a light guide that uniformly diffuses light from the LED light emitter in the main scanning direction to form a rod light emitter. In this case, it is required to irradiate uniform light in the main scanning direction (line sensor arrangement direction).

Therefore, as shown in FIG. 21A, the illumination device forms the light guide A in a bar shape in which the diffusive reflection surface and the light emission surface are arranged to face each other in the scanning direction, and guides the light guide A. A light source B is disposed at one end of the light guide A in a state of being housed in a housing that also serves as a body holder C, and light emitted from the light source B is guided from one end to the other end of the light guide A. Thus, the linear light emitted from the light emitting surface toward the subject is made uniform.

And the illuminating device which irradiates uniform linear light forms several protrusion part A1, A2 in the side surface of the rod-shaped light guide A at predetermined intervals along a longitudinal direction, and light guide holder C Each of the protrusions A1 of the light guide A is formed with a recessed groove C1 so that the protrusion A1 can be inserted from the light emitter side, and each protrusion A1 of the rod-shaped light guide A is formed with respect to the groove C1 of the light guide holder C from the light emitter side. The light guide A housed in the light guide holder C is prevented from popping out by being pushed in and covered with the light source holder.

In addition, when the rod-shaped light guide A is pushed into the light guide holder C from the light emitter side in this way, the rod-shaped light guide A has each of the light guides A as shown in FIG. The protrusions A1 and A2 can be formed to be connected.

Further, unlike the structure in which the rod-shaped light guide A is pushed into the light guide holder C from the light emitter side as in the illumination device disclosed in Patent Document 1 described above, the rod-shaped light guide A is arranged in the longitudinal direction. Patent Literature 2 and Patent Literature 3 are known as having an illuminating device having a structure to be inserted into the light guide holder C from above in an orthogonal direction.

First, as shown in FIG. 22, the illumination device disclosed in Patent Document 2 has a plurality of protrusions A1 and A2 formed on the side surface of the rod-shaped light guide A at predetermined intervals along the longitudinal direction. The light guide A is provided with a pressing member D formed with a locking claw D1 that faces each protrusion A1 of the light body A and locks with each protrusion A1, and the light guide A accommodated in the light guide holder C by the pressing member D. Each protrusion A1 of the light guide A is pressed into the light guide holder C from above so as not to jump out.

Further, as shown in FIG. 23, the illumination device disclosed in Patent Document 3 has a plurality of protrusions on the side surface of the rod-shaped light guide A at predetermined intervals along the longitudinal direction, like the light guide of Patent Document 2. In addition to forming portions A1 and A2, locking holes C1 and C2 are formed in positions where the protruding portions A1 and A2 of the light guide A can be locked in the light guide holder C that houses the light guide A, respectively. The light guide A accommodated in the light guide holder C is prevented from popping out by the locking mechanism of the locking holes C1 and C2 of the light guide holder C and the protrusions A1 and A2 of the light guide A. Yes.

Furthermore, as shown in FIG. 24, the illumination device disclosed in Patent Document 4 uses a plurality of light emitters, and the incident surface of the light guide is not sufficiently large with respect to the irradiation surface of the light emitter, As a countermeasure to make it difficult to capture light, there has been known one in which the incident surface of the light guide is expanded into a trumpet shape as illustrated.

The light guide used in the above-mentioned Patent Documents 1 to 4 is made of, for example, an acrylic resin and a highly transparent light-transmitting resin material, and the light guide body and the above-described protrusions are integrally formed. Is formed.

JP-A-6-217084 Japanese Patent Laid-Open No. 10-190962 JP 2002-190917 A JP-A-9-233263

By the way, as shown in Patent Documents 1 to 3 described above, when a plurality of protrusions A1 and A2 formed at predetermined intervals along the longitudinal direction are formed on the side surface of the rod-shaped light guide A, the rod-shaped light guide is formed. Reflection spots are generated when light propagating through the body A enters and exits the plurality of protrusions A1 and A2, and light that enters the plurality of protrusions A1 and A2 protrudes from the protrusions A1 and A2. Leaks out of the rod-shaped light guide A from the end surface on the far side in the longitudinal direction of the light source, causing a change in the state of the reflected light, and as a result, the spectral characteristic of the linear light changes, thereby obtaining an appropriate spectral characteristic. Therefore, there is a problem that illumination spots are generated in the illumination light of the illumination device, and when this illumination device is used as a light source of the image reading device, the illumination spots become a light amount unevenness of the read image and an appropriate image reading process cannot be performed. Yes.

Further, as means for solving the problem, for example, as shown in FIG. 21B of Patent Document 1, the problem is solved by extending the protruding portions A1 and A2 over the entire length of the light guide A in the longitudinal direction. I can do it. However, when the protrusions A1 and A2 are formed up to the vicinity of the incident end of the light guide, the spectral characteristics of the linear light change due to the influence of reflected light propagating through the protrusions A1 and A2. Appropriate spectral characteristics cannot be obtained, so that illumination spots appear in the illumination light of the illumination device, and when this illumination device is used as a light source of an image reading device, the illumination spots become the light intensity unevenness of the read image. There arises a problem that processing cannot be performed.

Furthermore, as shown in Patent Document 4 described above, the incident surface side of the light guide A facing the light emitter B is formed in a trumpet shape so as to increase the amount of light incident on the light guide. Although the amount of light to be increased can increase the amount of light applied to the entire light guide, the difference in the amount of light at both ends of the light guide becomes large and it is necessary to balance the amount of light. The problem also arises due to the increase in size.

Therefore, in view of the above-described problems, an object of the present invention is to provide an illuminating device that suppresses illumination unevenness and hardly causes unevenness in the read image in the image reading apparatus.

In order to achieve the above object, in the illumination device according to claim 1 of the present invention, a light emitter, a light guide that receives light from the light emitter and irradiates it as a linear light source, and supports the light guide. A light guide body supporting member, wherein the light guide body has a rod-like shape extending in a longitudinal direction, and at least one of both end portions faces the light emitter and receives light. And the first and second side surfaces that extend in the longitudinal direction opposite to each other and reflect the light incident from the incident surface in the longitudinal direction, and the reflected light that reflects the first and second side surfaces as the longitudinal direction. A reflection surface that reflects in the intersecting direction and an emission surface that emits the reflected light reflected by the reflection surface as illumination light are formed and protrudes from at least one of the first and second side surfaces in the longitudinal direction. A protrusion extending along the light emitter, the protrusion being opposed to the light emitter. Extending from a projecting formation position spaced a predetermined distance in the longitudinal direction from an end surface forming the incident surface, the inner surface of which forms a reflective surface together with the first and second side surfaces, and the first and second surfaces The side surface of the protrusion is formed in a wide shape sequentially from the protrusion formation position of the protrusion toward the incident surface, and the reflection surface is formed toward the other end with the incident surface side as one end, and one end of the protrusion is the protrusion. A reflection pattern is formed which is set on the other end side from the protruding formation position and whose width in the direction orthogonal to the longitudinal direction is sequentially enlarged from one end to the other end .

Further, in the illumination apparatus according to claim 2 of the present invention, in the illumination apparatus according to claim 1, the first light guide member, a second side, of the light guide has at least a first curvature It is formed by a curved surface comprising a curved portion which connects the reflecting surface of the curved surface portion and the light guide has a second curvature which connects the exit surface, the width of the reflective surface, the first in accordance with the longitudinal width position The curvature of 2 is changed in size.

Furthermore, in the image reading apparatus according to claim 3 of the present invention, an illumination device that irradiates light to the subject, an image reading sensor that receives reflected light from the subject, and an image reading control device that controls the image reading sensor. The lighting device comprises the lighting device according to claim 1 or 2 .

The present invention has the following effects.

First, in the illuminating device according to claim 1, the projecting portion that projects from at least one of the first and second side surfaces and extends along the longitudinal direction forms an incident surface on which the light emitter faces. The first and second side surfaces are extended in the longitudinal direction from the projecting formation position in front of the illumination reference region and spaced apart from the end surface, and the inner surface forms a reflective surface together with the first and second side surfaces, and the first and second side surfaces are The width of the entire light guide is increased by forming the first and second side surfaces wider by using the portions where the protrusions are not formed, by forming the protrusions sequentially from the protrusion toward the incident surface. Without increasing the size, it is possible to increase the width of the incident surface facing the light emitter, so that light from the light emitter can be taken in without loss, and illumination with high brightness is possible.

Furthermore, in the illumination device according to claim 1 , the reflection surface of the light guide is formed toward the other end with the incident surface side as one end, and one end thereof is set on the other end side from the protrusion formation position of the protrusion. In addition, by forming a reflection pattern in which the width in the direction perpendicular to the longitudinal direction is sequentially enlarged from one end to the other end, the irradiation light amount of the entire light guide is increased and compared to the increase in the light amount on the one end side. The amount of increase in the amount of light on the other end side can be increased, so that illumination light having an optimal light amount balance can be formed in the illumination region of the light guide.

Further, in the illumination apparatus according to claim 2, first the light guide illumination system as recited in claim 1 above, the second aspect, the exit surface of the light guide has at least a first curvature A curved surface portion (R50) connected to the light guide and a curved surface portion (R10) connected to the reflective surface of the light guide with a second curvature, and the width of the reflective surface is at the width position in the longitudinal direction. Accordingly, since the second curvature is formed by changing the size of the second curvature, the bottom surface of the light guide forming the reflective surface itself forms a reflection pattern shape, and the reflective paint is simply applied to the bottom of the light guide. The optimum reflection pattern can be easily formed by simply

Furthermore, in the image reading apparatus according to the third aspect , by using the illumination apparatus according to the first or second aspect , it is possible to perform an optimal image reading without a light amount unevenness.

1 is a cross-sectional view showing an overall configuration of an image reading apparatus according to the present invention. FIG. 2 is a cross-sectional view illustrating a configuration of a reading carriage that reads a document image in the image reading apparatus of FIG. 1. FIG. 2 is a perspective view showing an external structure of a carriage in the image reading apparatus of FIG. 1. The perspective view which shows the external appearance structure which looked at the carriage of FIG. 3 from the downward direction. The top view which shows the external appearance structure which looked at the carriage of FIG. 3 from upper direction. FIG. 4 is an exploded perspective view showing an illumination device mounted on the carriage of FIG. 3. The partial exploded side view of the illuminating device of FIG. The partial exploded perspective view of the illuminating device of FIG. It is a principal part enlarged view in the illuminating device of FIG. 8, (a) is a side fragmentary sectional view, (b) is the external view seen from the one end light-emitting body side of a light guide, (c) is from the other end side of a light guide. External view seen. It is the schematic explaining the shape of the light guide in the illuminating device of FIG. 6, (a) is a principal part expansion perspective view, (b) is the top view seen from the reflective surface side, (c) is the figure (b). 2A is a cross-sectional view at the position a, FIG. 3D is a cross-sectional view at the position b in FIG. 2B, and FIG. 3E is a cross-sectional view at the position c in FIG. The cross-sectional enlarged view explaining the light guide support mechanism of the illumination unit of FIG. The top view seen from the light guide body explaining the light source unit in the illuminating device of FIG. The cross-sectional enlarged view of the light source unit of FIG. The disassembled perspective view of the light source unit of FIG. It is a figure which shows the structure of the light-emitting body of a light source unit of FIG. 14, and a light-emitting-body board | substrate, (a) is a top view which shows the light source feed circuit pattern wiring of a light-emitting body board | substrate, (b) is sectional drawing of the ZZ plane, (C) is a top view which shows the terminal pattern of a light source. It is a figure for demonstrating the positional relationship of the light-emitting body and light guide in the illuminating device of FIG. 8, (a) is a side view, (b) is the light-emitting body with respect to the light guide seen from the one end light-emitting body side of a light guide. The top view which shows the position of this, (c) is a top view which shows the position of the light-emitting body seen from the other end side of the light guide. FIG. 17 is an enlarged plan view showing the position of the light emitter with respect to the light guide in FIG. It is a figure for demonstrating the positional relationship of the light-emitting body and light guide in the illuminating device regarding the other Example corresponding to FIG. 16, (a) is a side view, (b) is seen from the one end light-emitting body side of a light guide. The top view which shows the position of the light-emitting body with respect to the guided light guide, (c) is a top view which shows the position of the light-emitting body seen from the other end side of the light guide. FIG. 6 is a spectral characteristic diagram showing spectral characteristics of the illumination device in the image reading apparatus of the present invention. 1 is a functional block diagram showing a control system for reading a document image in the image reading apparatus of FIG. 1 shows Patent Document 1 related to a conventional lighting device, in which (a) is a perspective view showing an overall configuration, and (b) is an external perspective view of a light guide. It shows patent document 2 related to a conventional lighting device, (a) is a perspective view showing the overall configuration, (b) is a cross-sectional view of the main part. 1 shows Patent Document 3 related to a conventional lighting device, in which (a) is a perspective view showing an overall configuration, (b) is a cross-sectional view of a main part, and (c) is a cross-sectional view of a main part at a different position. Patent Document 4 related to a conventional lighting device is shown, and (a) shows the overall configuration.

Hereinafter, an embodiment of an image reading apparatus equipped with the illumination device according to the present invention based on FIGS. 1 to 17, spectral characteristics of the illumination device in the image reading apparatus of the present invention based on FIG. Each of the image data processing units for reading a document image of the image reading apparatus will be described.

[One Example of Image Reading Apparatus]
First, an embodiment of an image reading apparatus equipped with an illumination device according to the present invention will be described with reference to FIGS. FIG. 1 shows the overall configuration of the image reading device, FIGS. 2 to 5 show the configuration of a reading carriage mounted on the image reading device, and FIGS. 6 to 10 show the illumination device serving as the light source of the reading carriage. FIGS. 12 to 17 are for explaining the configuration of the light source unit of the illumination device.

<Overall configuration of image reading device>
FIG. 1 is a cross-sectional view showing the overall configuration of the image reading apparatus. This image reading apparatus is composed of the following image reading unit A and a document feeding unit B mounted thereon.

(Image reading unit A)
The image reading unit A includes a first platen 2 and a second platen 3 in the apparatus housing 1. The first platen 2 and the second platen 3 are made of a transparent material such as glass and are fixed to the top of the apparatus housing 1. The first platen 2 is formed with the maximum size of a usable document that can be manually placed, and the second platen 3 is formed with the maximum width of the usable document so as to read a document that moves at a predetermined speed. Yes. The first platen 2 and the second platen 3 are arranged side by side, guided below by the guide shaft 12 and the rail member GL, and supported in the apparatus housing 1 so as to be movable parallel to the platen surface. A reading carriage 6 reciprocated by Mc is incorporated.

(Original Feed Unit B)
The document feeding unit B is disposed above the first platen 2 and the second platen 3 so as to cover the first platen 2 and the second platen 3, and a lead roller (document feeding means) 21 and a carry-out roller 22 that feed the document sheet to the second platen 3. And. Further, on the upstream side of the read roller 21, a paper feed stacker 23 for stacking and storing original sheets, a paper feed roller 24 for separating and feeding the sheets stacked on the paper feed stacker 23 one by one, and separation feeding A registration roller pair 25 for correcting the skew of the leading edge of the sheet is disposed. Further, a lead sensor S 1 for detecting the leading edge of the original reaching the second platen 3 is provided in the paper supply path 26 for guiding the original sheet from the paper supply stacker 23 to the second platen 3, and the upper surface of the second platen 3. The backup roller 27 is arranged at the same peripheral speed as the lead roller 21, fits the original sheet on the second platen 3, and conveys it to the carry-out roller 22 arranged downstream of the platen. Further, on the downstream side of the carry-out roller 22, a paper discharge stacker 29 arranged in a vertically parallel manner is disposed below the paper discharge roller 28 and the paper feed stacker 23, and the first platen 2 is disposed at the bottom of the paper discharge stacker 29. There is provided a platen cover 5 for pressing and supporting a document sheet placed thereon.

<Double-sided scanning mechanism>
Further, an image reading unit for reading the reverse side of the original surface read by the image reading unit A almost simultaneously inside the original reversing path guide formed by the registration roller pair 25, the read roller 21, the backup roller 27, and the carry-out roller 22. C is disposed. Details of the image reading unit C will be described later.

In place of the backup roller 27, a backup guide may be arranged above the platen. In the image reading apparatus described as the first embodiment described above, the first platen 2 and the second platen 3 are arranged side by side, and the document feeding unit B is mounted thereon. An image reading apparatus in which the two platen 3 is removed and only the first platen 2 is provided, an opening / closing cover is attached instead of the document feeding unit B, and the opening / closing cover covers the first platen 2 may be used.

(Original Fixed Reading Mode <Flatbed Mode>)
The document feeding unit B configured as described above is set on the first platen 2 by the operator selecting the document fixed reading mode, so-called flatbed mode, on the apparatus panel of the image reading unit A or on the screen of the PC. When the original sheet is read, the original sheet is placed on the apparatus housing 1 of the image reading unit A so as to be freely opened and closed, the original feeding unit B is lifted upward, and the first platen 2 is opened. The document sheet is covered with the platen cover 5 of the document feeding unit B, and the reading carriage 6 moves along the guide shaft 12 below the document sheet to perform a reading operation.

(Original scanning mode <sheet-through mode>)
Also, the document feeder unit B has a second platen that is transported by the document feeder unit B when the operator selects a document flow scanning mode, so-called sheet-through mode, on the apparatus panel of the image reading unit A or on the screen of the PC. 3, the reading carriage 6 is moved along the guide shaft 12 to the reading position of the second platen 3 by the carriage motor Mc and stopped to read the conveyed document sheet. Do.

<Configuration of reading carriage>
Next, the reading carriage 6 will be described. 2 is a cross-sectional view showing a configuration of a reading carriage 6 that reads an original image in the image reading unit A of FIG. 1, FIG. 3 is a perspective view showing an external structure of the reading carriage 6, and FIG. 4 shows the reading carriage 6 of FIG. FIG. 5 is a plan view showing the external structure of the reading carriage 6 shown in FIG. 3 as viewed from above.

First, the reading carriage 6 will be described with reference to FIG. The reading carriage 6 includes an illumination unit 9 (illumination device) and a unit frame 11 constituting an optical unit. Then, as shown in the figure, a recess for completely storing the illumination unit 9 is formed in the top of the unit frame 11 made of heat-resistant resin and a metal plate, and the illumination unit 9 can be detachably attached to the recess. It has become. The illumination unit 9 includes a pair of first light guide 9a and second light guide 9b, and a light guide housing portion 13 (guide for housing the pair of first light guide 9a and second light guide 9b. Optical body holder) and a metal or a metal equivalent rigid body KF that eliminates warpage due to molding of parts of each of the light guides 9a and 9b and the light guide housing portion 13 and changes over time. The optical unit also includes a reflection mirror 10 composed of a first mirror 10a to a sixth mirror 10f for deflecting reflected light from the original sheet illuminated by the light of the illumination unit 9, and an original sheet reflected from the reflection mirror 10. A condensing lens 7 that condenses the reflected light and a line sensor 8 (imaging device) disposed in an image forming portion that forms an image with the condensing lens 7 form a reduction optical system. The image data output as an electrical signal from the line sensor 8 is electrically connected to an image processing unit (data processing board) to be described later by a data transfer cable (not shown) so as to be transferred to the image processing unit.

As shown in FIGS. 2 and 3, a reading opening 34 corresponding to the reading line width W of the original sheet is formed in the illumination unit 9 housed in the recess of the unit frame 11. The line sensor 8 disposed in the unit frame 11 can receive the reflected light reflected from the reading surface of the original sheet irradiated with light. The unit frame 11 is movably supported by the guide shaft 12 and the rail member GL so as to reciprocate with a predetermined stroke.

The illumination unit 9 will be described in detail as an illumination device to be described later. The illumination unit 9 is composed of a linear light source that irradiates linear light along the reading opening 34, and is attached to the recess of the unit frame 11 with screws or the like for illumination system maintenance. The reading light is irradiated from a reading opening 34 onto a document sheet on a platen described later.

The reflection mirror 10 is appropriately composed of a plurality of sheets so as to form a predetermined optical path length, and in the case of this embodiment, it is composed of six sheets. Reflected light from the image reflected on the original surface of the original sheet by the first mirror 10a is reflected toward the second mirror 10b, and the reflected light is reflected by the second mirror 10b and reflected toward the third mirror 10c. The reflected light is reflected by the third mirror 10c and again reflected toward the second mirror 10b, the reflected light is reflected toward the fourth mirror 10d, and the reflected light is reflected by the fourth mirror 10d, and the reflected light is reflected. The light is reflected toward the fifth mirror 10e. Finally, the reflected light reflected by the fifth mirror 10e is guided to the sixth mirror 10f, and the reflected light reflected by the sixth mirror 10f is converted into the condenser lens 7. To guide. The reflected light of the document image is not limited to such an optical path formation, and it is possible to form an optical path using, for example, first and second reflection mirrors.

The condensing lens 7 is composed of one or a plurality of concave and convex lenses, and condenses the reflected light reflected from the original surface of the original sheet transmitted through the reflecting mirror 10 and forms an image on the line sensor 8.

The line sensor 8 is composed of a photoelectric conversion sensor such as a CCD, and receives and photoelectrically converts the reflected light of the document image sent from the condenser lens 7. This line sensor 8 is composed of a color line sensor, and the sensor elements constituting R (Red), G (Green), B (Blue), and BW (Black and White) pixels are arranged in four lines in a line. ing. The line sensor 8 having such a configuration is attached to the sensor circuit board 45, and the sensor circuit board 45 is fixed to the unit frame 11.

<Reading carriage support mechanism>
As shown in FIGS. 3 to 5, the reading carriage 6 has one end pivotally supported by the guide shaft 12 by a bearing disposed in the apparatus housing 1, and the other end of the reading carriage 6 is slidable on the rail member GL. The device housing 1 is supported so as to be reciprocally movable. The carriage support mechanism composed of the guide shaft 12 and the rail member GL is attached to the apparatus housing 1 in parallel with each other and to both the first platen 2 and the second platen 3 in parallel. The platen 2 and the second platen 3 are opposed to the plane and are configured to reciprocate stably in parallel.

<Scanning carriage movement mechanism>
The carriage movement mechanism of the reading carriage 6 includes a carriage motor Mc composed of a drive motor such as the pulse motor and the DC motor with an encoder shown in FIG. 1, a wire that rotates by the reciprocating rotation of the carriage motor Mc, a timing belt, and the like. The pulling member 17 and a pair of pulleys 46a and 46b rotatably supported by the apparatus frame 1 are configured. A carriage motor Mc that can be rotated forward and backward is connected to the one pulley 46b, a traction member 17 is stretched between the pair of pulleys 46a and 46b, and the reading carriage 6 is connected to the traction member 17 to move the carriage. The mechanism is configured.

<Reading operation of reading carriage>
The reading carriage 6 connected to the above-described carriage moving mechanism is a reference white for adjusting a light quantity characteristic (not shown) disposed at a position corresponding to the home position HP shown in FIG. 1 when the power is turned on or reading is completed, that is, above the home position HP. 1 is stopped in the position where the light of the illumination unit 9 illuminates the shading plate having a predetermined area (and reference black if necessary), and according to the mode selected from its home position HP, In the original fixed reading mode, the reading carriage 6 moves to the position indicated by the two-dot chain line in FIG. 1 to perform the reading operation.

<Configuration of lighting device>
Next, an illumination device that is attached to the above-described reading carriage 6 and used as the illumination unit 9 will be described with reference to FIGS. 6 is an exploded perspective view showing the lighting device mounted on the carriage of FIG. 3, FIG. 7 is a partially exploded side view of the lighting device of FIG. 6, and FIG. 8 is an exploded perspective view of the light source unit portion of the lighting device of FIG. FIG. 9 is an enlarged view of a main part of the lighting device of FIG. 8, FIG. 9A is a partial side sectional view, FIG. 9B is an external view of the light guide viewed from one end light emitter, and FIG. FIG. 10 is a schematic view for explaining the shape of the light guide in the lighting device of FIG. 6, (a) is an enlarged perspective view of the main part, and (b) is a view from the reflecting surface side. (C) is a cross-sectional view at the position a in FIG. 4 (b), (d) is a cross-sectional view at the position b in FIG. 5 (b), and (e) is a cross-sectional view at the position c in FIG. It is sectional drawing.

The illumination unit 9 constituting this illumination apparatus irradiates linear light along a reading line that forms a reading width in the main scanning direction orthogonal to the reading surface R shown in FIG. The illumination unit 9 is composed of a light guide unit Ga and a light source unit La as shown in FIGS. The light guide unit Ga includes two parts, a first light guide 9a and a second light guide 9b shown in FIG. The first light guide body 9a and the second light guide body 9b are held by light guide body holding members T1 and T2 on a rigid body KF such as a metal fixed and supported on the unit frame 11 of the carriage 6 shown in FIG. It is accommodated in the 1st accommodating part 13a and the 2nd accommodating part 13b which were formed in the light guide accommodating member (light guide holder) 13 to be performed. One end of each of the first light guide 9a and the second light guide 9b is disposed to face each light emitter 40 of the light source unit La that supports the light emitter (light source) 40 as shown in FIG. The configuration of the light source unit La and the configuration of the light guide unit Ga will be described in detail.

<Configuration of light source unit>
First, the configuration of the light source unit La will be described in detail with reference to FIGS. 8 and 12 to 15. 12 is a plan view of the light source unit La in the illumination device of FIG. 8 as viewed from the light guide 30 side, FIG. 13 is an enlarged sectional view of the light source unit La of FIG. 12, and FIG. 14 is a diagram of the light source unit La of FIG. FIG. 15 is an exploded perspective view, FIG. 15 is a view showing a structure of a light emitter substrate to which the light emitter 40 of the light source unit La of FIG. 14 is electrically attached, and (a) is a plan view showing a light source feeding circuit pattern wiring of the light emitter substrate. (B) is a cross-sectional view of the ZZ plane, and (c) is a plan view showing a terminal pattern of the light emitter.

As shown in FIG. 8, the light source unit La is composed of a heat radiating member 14, a heat conductive sheet 15, a circuit board 16, and an insulating mylar 47. The light source unit La is made of metal or a rigid body KF equivalent to metal shown in FIG. It is attached using screws. Further, as shown in FIG. 14, a first light emitter (white LED) 41 and a second light emitter (white LED) 42 and a lens cap 43 are attached to the circuit board 16, respectively, and a reflector 49 is placed thereon. It has been. In addition, an insulating mylar 47 that insulates portions other than those covered by the reflector 49 is provided. In the following, description of individual parts and unit assembly will be described.

(Description of luminous body)
First, the light emitter 40 will be described with reference to FIGS. The light emitting body 40 is composed of two light emitting elements, a first light emitting body 41 and a second light emitting body 42, respectively, and the light emitting elements are composed of white LED chips. In addition, as shown in FIG. 15C, the light emitter 40 forms an anode 40a and a cathode 40b for supplying power, and also forms a thermal pad 40c for heat dissipation, and is electrically formed on the wiring pattern of the circuit board 16. Mounted.

(Description of circuit board)
The circuit board 16 on which the light emitting body 40 is mounted is fixed to the heat radiating member 14 via the heat conductive sheet 15 as shown in FIG. 15B, and the light emitting body 40 is mounted on the circuit board 16. As shown in FIG. 15 (a), the circuit board 16 has a wiring pattern 16a-1 made of a material having high conductivity such as copper, silver, gold, etc. for emitting and energizing the light emitter 40 on the surface of the circuit board. 16a-5 are formed, and the back surface of the substrate is covered with a heat conductive layer 16b-2 having a particularly high thermal conductivity such as copper, silver, and aluminum, and a part of the heat conductive layer is formed on the light emitting body 40. The protrusion 16b-1 is formed on the substrate surface so as to be in direct contact with the light emitting source. The circuit board 16 has a particularly high thermal conductivity such as copper, silver or aluminum on the back surface of the circuit board 16 in a state where a through hole for forming the protrusion 16b-1 is previously formed in an insulating board made of an epoxy material. After forming the heat conductive layer 16b-2 and the protrusion 16b-1 by injection molding of the heat conductive material, a layer made of a material having high conductivity such as copper, silver, gold or the like is formed on the substrate surface. Is formed by etching so as to leave the wiring patterns 16a-1 to 16a-5 and the protrusions 16b-1. The circuit board 16 has the light emitter 40 mounted thereon, and the thermal pad 40c of the light emitter 40 and the protruding portion 16b-1 protruding from the back surface of the substrate are in pressure contact with each other, so that the heat generated when the light emitter 40 is turned on. Is radiated to the heat conductive layer 16b-2 on the back surface of the substrate through the protrusion 16b-1 in contact with the thermal pad 40c.

The circuit board 16 may be formed in multiple layers. In this case, it is desirable that the heat conductive layer 16b-2 on the back surface of the circuit board and the projecting part 16b-1 projecting on the surface of the board be connected so as to maintain high heat conduction. Moreover, you may comprise so that the heat | fever of the light-emitting body 40 may be conducted to the thermal radiation member 14 through the anode 40a and the cathode 40b.

(About heat conduction sheet)
The thermal conductive sheet 15 is an elastic sheet material made of an insulating synthetic resin having high thermal conductivity made of, for example, a thermoplastic elastomer or a non-silicone thermoplastic resin and rich in elasticity. ) As shown by a dotted line, the heat of the luminous body 40 interposed between the circuit board 16 and the heat radiating member 14 described later and radiated to the heat conductive layer 16b-2 of the circuit board 16 is efficiently conducted to the heat radiating member 14. It is provided for.

(About heat dissipation member)
Further, the heat radiating member 14 is commercially available as a heat sink, and is composed of a metal material having a high thermal conductivity such as an aluminum alloy. In order to increase the surface area, for example, as shown in FIG. The heat of the luminous body 40 conducted through the above-described heat conductive sheet 15 is efficiently radiated.

(Insulation Mylar)
Further, as shown in FIG. 8, an insulating mylar 47 is provided on the surface of the circuit board 16 on the light guide 30 side. The insulating mylar 47 insulates the wiring pattern of the circuit board 16 so that it does not come into contact with the metal member constituting the rigid body KF, and protects the surface of the circuit board 16 so that the surface of the board is not damaged.

(About reflector)
Further, as shown in FIGS. 8 to 14, in order to make the light from the light emitter 40 enter the light guide 30 without loss, the spectral characteristics of the first light emitter 41 and the second light emitter 42 of the light emitter 40 are set to 90. A reflector 49 that regulates within ± is provided. One reflector 49 is provided for each light emitter. The reflector 49 is made of a material having a high reflectivity obtained by evaporating a metal such as aluminum on a plastic material, and has an umbrella shape extending from the light emitting body 40 toward the light guide body 30. At this time, the umbrella-shaped portion may be formed with a curved surface or an inclined plane.

(Separation between light emitters of reflectors)
Next, it supplements about isolation between the light-emitting bodies by a reflector. As shown in FIGS. 12 and 13, the first light-emitting body 41 and the second light-emitting body 42 are separated from each other by the reflector 49 in the light irradiation area, and the light guide body is separated from the one end face 30 </ b> L of the light guide body 30. By separating the lights entering the light 30, the spectral characteristics of the first and second luminous bodies 41 and 42 are individually regulated, and the first and second luminous elements are regulated to the optimum spectral characteristics. Light from the second light emitters 41 and 42 can be incident on the end face of the light guide only from the region restricted by the reflector, and illumination spots can be further suppressed.

(About holding member)
Similarly, as shown in FIG. 9, the holding member 48 shown in FIG. 8 presses and urges the heat radiating member 14 and the protruding piece 30 </ b> N provided at one end 30 </ b> L of the light guide 30 through the reflector 49. This is for regulating the gap between the body 30 and the light emitter 40 to be constant. Accordingly, the holding member 48 is formed of a spring member having rigidity such as a metal having a spring property, and pulls the light guide 30 toward the heat radiating member 14 and pulls the heat radiating member 14 toward the light guide 30. .

<Assembly of light source unit>
Next, the assembly of the light source unit La will be described with reference to FIGS. First, the light emitters 40 (41, 42) are mounted on the circuit board 16 as shown in FIGS. 12 to 14, and the lens cap 43 is attached as shown in FIG. With the circuit board 16 in close contact with the heat radiating member 14 (heat sink) through the heat resistant sheet 15 (heat resistant resin plate) as shown in FIG. 8, the heat radiating member 14 and the rigid body KF are screwed as shown in FIG. Attach it as a unit. Then, the light guide 30 and the heat radiating member 14 attached to the rigid body KF in another light guide unit assembly process shown in FIG. 6 are used to hold the reflector 49 of the light source unit La using the holding member 48 as shown in FIG. The light guide unit Ga is held in pressure contact with one end face of the light guide 30. The light source unit La that has been assembled is mounted on the carriage 6 by attaching the rigid body KF to the unit frame 11 of the carriage 6 with screws or the like.

<Configuration of light guide unit>
Next, the light guide unit will be described with reference to FIGS. 6, 9 and 10, and FIGS. 16 and 17. As shown in FIG. 6, the light guide unit Ga includes a light guide 30 (30a, 30b), a light guide housing member (light guide holder) 13, and a light guide holding member T (T1, T2). And is attached to a rigid body KF that supports the light source unit La.

As shown in FIGS. 9 and 10, the light guide 30 includes an incident surface 30 </ b> L on which light from the light emitter 40 is incident, and light incident on one end surface of the incident surface 30 </ b> L in the longitudinal direction of the other end surface 30 </ b> R. The reflecting side surfaces 30S that face each other and extend in the longitudinal direction, the reflecting surface 32 that reflects the reflected light reflected by the facing side surfaces 30S in the direction intersecting the longitudinal direction, and the reflected light that is reflected by the reflecting surface 32 are illuminated. An emission surface 33 that emits light, a protrusion 30P that protrudes from at least one of the side surfaces 30S and extends in the longitudinal direction, and a protruding piece 30N that protrudes in a fan shape from the incident surface 30L are formed, and a reading opening 34 (refer to FIG. 3) is a rod-like light-transmitting member having a rod-like shape extending in a length corresponding to a reading width (reading line width) W along the longitudinal direction of light, for example, transparent acrylic resin, epoxy resin, etc. Rich in nature It is composed of a material's. Further, as shown in FIG. 9, the reflecting surface 32 and the emitting surface 33 are formed to face each other with a length of the reading line width W approximately parallel to each other at a distance Ld. It is connected with 30S. In addition, the light emitting body 40 is disposed on the incident surface 30L, the other end surface 30R is mirror-finished, and the outer surface thereof has a reflective layer 50 having a highly reflective layer such as aluminum or silver so as to form a reflective surface. However, it is affixed by the adhesive material (double-sided tape) 60 with a light transmittance of 90% or more.

<Description of reflective surface>
10B, the reflecting surface 32 of the light guide 30 forms a pattern surface whose width gradually increases from the incident surface 30L side of the one end surface to the other end surface 30R side. The reflective surface 32 is surface-treated so as to diffusely reflect the light introduced and formed on the concavo-convex surface by, for example, coating, etching, molding, or the like with a reflective paint such as urethane white ink. The surface processing is not performed on the side close to the incident surface 30L of the light guide 30 as shown in FIGS. 9 and 10, but from the place where a certain distance has passed from the incident surface 30L to the other end surface 30R. As shown in FIG. 9, the base end portion on the incident surface 30L side is formed between the base end portion of the reading line width W and the base end portion on the incident surface 30L side of the protruding portion 30P protruding from the side surface 30S. It is provided in between. This is because the incident surface 30L of the light guide 30 described later makes it easy to sufficiently capture the light of the light source unit La, using the protrusion width of the protrusion 30P, and the incident surface 30L of the protrusion 30P protruding from the side surface 30S. When the reading line width W and the surface processed portion have substantially the same length by adjusting the light amount by gradually increasing the distance between the side surfaces 30S facing each other from the base end portion on the side, and forming the trumpet shape, the reading line width W The peak of the light quantity on the 30L side is shifted to the 30R side, and the light quantity at the end on the 30L side is insufficient, so the light quantity distribution is set long in advance so as to be an appropriate value. Note that the shape of the pattern surface is formed by changing the curvature of the curved surface R10 that forms the side surface as will be described in detail in the description of the side surface described later, and the width of the pattern surface is slightly shifted from the actual pattern surface. It is set to be large in consideration.

<Explanation of exit surface>
Further, the exit surface 33 of the light guide 30 is formed as a circumferential surface as shown in FIG. The circumferential surface is formed with a radius of 3.7 mm ± 0.1 mm, and the center P1 of the circumferential surface is provided on a normal line hx that is the center of the illumination optical path. Then, as shown in FIG. 9, the light that has reached the emission surface 33 at an angle less than the critical angle among the light reflected and diffused by the surface of the reflection surface 32 is directed from the emission surface 33 toward the irradiation surface R (reading surface). And exit. For this reason, the reflecting surface 32 is located outside the circumferential region, and the position is set to a position of 8.46 mm ± 0.1 mm from the emitting surface 33 on the normal line hx.

<Description of side>
Further, the side surface 30S of the light guide 30 has a shape on both sides, and has a curved surface in which two or more curvatures are connected and different curvatures are connected without corners. Specifically, as shown in FIGS. 10C to 10E, the curvature of the portion connected to the emission surface 33 side is constant R50 (for example, radius 50 mm) and the portion connected to the reflection surface 32 side. The curvature is changed in the longitudinal direction in accordance with the width abc of the reflecting surface 32 in the order of R10 (for example, radius 10 mm), R15 (for example, radius 15 mm), and R30 (for example, radius 30 mm). Due to this change in curvature, the reflecting surface 32 forms a pattern surface having a width that gradually increases from the incident surface 30L side of the one end surface to the other end surface 30R side, and a reflective paint such as urethane-based white ink is uniformly applied to this pattern surface. The reflective surface 32 can be easily formed by painting.

<Side trumpet shape>
As shown in FIGS. 10A and 10B, the side surface 30S uses the protruding width of the protruding portion 30P so that the incident surface 30L of the light guide 30 can sufficiently capture the light of the light source unit La. In addition, the protrusion 30P protruding from the side surface 30S is formed in a trumpet shape by gradually increasing the distance between the side surface 30S facing the base end portion on the incident surface 30L side. By using the protruding width of the protruding portion 30P to form the trumpet, it is not necessary to increase the allowable width of the light guide, and the compactness of the apparatus can be maintained. Further, by using a trumpet-shaped curved surface, it is possible to increase the amount of reflected light toward the other end surface 30R side by increasing the reflection angle of the light incident from the incident surface 30L toward the other end surface 30R. Light quantity adjustment is easy.

<Explanation of protrusion>
Moreover, the protrusion part 30P which protrudes from the side surface 30S is demonstrated based on FIG.9 and FIG.10. This protrusion 30P is a bowl-shaped protrusion that protrudes from the central portion of the side surface 30S as shown. The protruding portion 30P is not provided in the vicinity of the one end portion 30L, and has a base end portion between the base end portion of the reflection surface 32 and the incident surface 30L, and is formed between the other end portion 30R. Has been. This is to prevent the projection 30P from being extended to the incident surface 30L and light from being irregularly reflected by the projection 30P to affect the spectral characteristics, and to prevent the amount of reflected light from being attenuated by going out of the portion to the outside. is there. In addition, this protrusion part 30P is the light guide holding member T (T1, T2) in the rigid body KF in the state which accommodated the light guide 30 (30a, 30b) in the light guide storage part 13 (13a, 13b) mentioned later. In order to remove the warpage peculiar to the rod shape that occurs when the light guide 30 is processed or changes in diameter, the light guide 30 is continuously formed.

<Description of reflector>
Further, the reflecting plate 50 and the adhesive material 60 disposed on the other end surface 30R of the light guide 30 are formed as a single sheet-like material, and the adhesive material 60 is an acrylic sheet having a light transmittance of 90% or more. A reflective plate 50, which is a sheet base material having the above-described reflective surface formed on the front side, and a release sheet having a release surface (not shown) on the back side are overlapped on the front and back of the adhesive material 60. Configure the sheet material. In the present embodiment, the thickness of the reflection plate and the sheet material of the adhesive material is 25 micrometers. However, if the light transmittance can be ensured to be 90% or more, the thickness can be 25 micrometers or more. Then, the release sheet is peeled off from the adhesive material 60 from the sheet material that has been punched in conformity with the outer shape of the other end surface 30R of the light guide, and the reflection plate 50 to which the adhesive material 60 is attached is attached to the other end surface of the light guide. By attaching to 30R, the reflector attaching operation can be easily performed with good workability. Moreover, the adhesive material 60 is reliably provided between the reflector 50 and the other end surface 30R of the light guide by simply attaching the reflective plate 50 to which the adhesive material 60 is attached in advance to the other end surface 30R of the light guide. A constant gap can be provided on the one end face of the light guide body with a predetermined interval with the thickness of the material, and the reflector 50 is in a state close to the light irradiation environment of the light emitter. By creating a pseudo light source that more resembles a light emitter, the left and right uniform spectral characteristics can be obtained as linear light as well as the light emitters on both end faces of the light guide. It is done.

Further, as shown in FIG. 10, the reflection surface of the other end surface 30R can correct the above-mentioned light quantity characteristic by adjusting the angle by an angle θ in the length direction with respect to the normal direction hx of the reflection surface 32. Become. That is, as shown in FIG. 10, when the angle of this reflecting surface is tilted by plus θ clockwise, the light intensity at both ends of the main scanning direction increases, and conversely when tilted by minus θ counterclockwise, the light intensity at both ends of the main scanning direction becomes By reducing this angle and setting this angle when designing the light guide 30 in advance, it is possible to easily match the spectral characteristics of the condenser lens 7. The optimum value is about 10 °.

In addition, it is good also as a structure which inclines the other end part 30R artificially by changing the thickness of an adhesive sheet, without inclining the edge part of the light guide 30 by the side of a pseudo light-emitting body.

In addition, a light emitter that faces the light guide body at a predetermined interval is disposed on one end face 30L, and a reflection plate 50 is disposed on the other end face 30R. You may arrange | position a new light-emitting body by the structure similar to the light-emitting body of an end surface.

<Path from reflected light incidence to emission>
Therefore, the light of the light emitting body 40 introduced into the light guide 30 is diffused in a predetermined direction by the reflecting surface 32, and the light introduced into the emitting surface 33 is reflected to the inside when the angle is equal to or larger than a predetermined critical angle. The light is emitted to the outside in the following cases. The light indicated by the arrow ha in FIG. 9 is reflected in the light guide 30 and dispersed in the direction of the reading line width W, and the light indicated by the arrow hb is emitted from the emission surface 33 to the reading surface R. Although not shown, light is incident in a hemispherical direction (360-degree direction; the illustrated one is a 60-degree wide-angle direction) from a light-emitting body 40, which will be described later, and the light passes through the light guide 30 from one end 30L to the other end. Light that is repeatedly propagated to 30R and reflected on the exit surface 33 side by the reflecting surface 32 is emitted from the exit surface 33 to the outside of the light guide 30 along the way.

In addition, the light that has repeatedly reflected within the light guide 30 and reaches the other end surface 30R is reflected by the reflecting plate 50 with the adhesive material 60 attached to the surface of the other end surface 30R, and returned to the light emitting body 40 side. The light indicated by the arrow ha diffusely reflected by the surface 32 is emitted from the emission surface 33 to the reading surface R. Using this characteristic, the arrangement of the light emitter 40 with respect to the incident surface 30L is adjusted, the light emitted from the emission surface 33 on the incident surface 30L side to the reading surface R is lowered, and the light reflected on the surface of the other end surface 30R is increased. Thus, the amount of light on the incident surface 30L side can be decreased, the amount of light on the other end surface 30R side can be increased, the amount of light emitted to the reading surface R can be made uniform, and when the optical reduction system type condensing lens 7 is used It is possible to adjust the light amount close to the light amount distribution of the cosine fourth law that depends on the lens characteristics.

<Light guide housing member (light guide holder)>
Next, the light guide housing member 13 that houses the light guide 30 will be described. As shown in FIGS. 6 and 11, the light guide housing member 13 (13a, 13b) constitutes a light guide support means together with a light guide holding member T (T1, T2) described later. The light guide housing member 13 forms concave groove portions 13a and 13b extending in the longitudinal direction for housing the light guide body, and the groove portions 13a and 13b are the first and second groove portions 13a and 13b. First and second side wall portions 13c and 13d that face the side surface 30S, a bottom portion 13e that faces the reflecting surface 32 of the light guide 30, and a support surface that supports the light guide 30 in a predetermined posture in the groove. 13f is formed.

Further, one of the first and second side surfaces 30S of the light guide 30 is set as a reference mounting surface 30Sa, and the support surface 13f of the light guide housing member 13 is guided in a predetermined posture into the grooves of the groove portions 13a and 13b. In order to support the light body 30, a support curved surface that is in surface contact with the attachment reference surface 30Sa is formed.

The light guide housing member 13 is resin-molded because the inner surfaces of the groove portions 13a and 13b have a complicated shape, and warpage is likely to occur due to shrinkage or aging during molding. Therefore, as shown in FIG. 6, it is supported by a rigid body KF such as metal in order to eliminate the warpage. The supporting mechanism is formed with locking claw portions 13a1 and 13b1 that protrude from four positions on one side of the light guide housing member 13, and the locking claw portions 13a1 and 13b1 are inserted into the rigid body KF from above. The claw locking portions KF1 and KF2 are formed to expand the possible gaps and form a moving space that can move in the opposite direction to the light source unit La after insertion, and the claw locking portions KF1 and KF2 have locking claws It has the structure which latches part 13a1, 13b1.

<Light guide holding member>
On the other hand, the light guide holding member T (T1, T2) has the light guide 30 (30a, 30b) accommodated in the grooves 13a, 13b of the light guide accommodating portion 13 as shown in FIGS. It is for holding in the accommodation position, and extends along the longitudinal direction in parallel with the projection 30P of the light guide 30 accommodated in the grooves 13a and 13b of the light guide accommodation member 13, and above the projection 30P. The continuous contact surfaces T1b and T2b that contact the inclined surface, the locking portions T1a and T2a extending downward from the six positions of the contact surfaces T1b and T2b as shown in FIG. 6, and the locking portion T1a , Locking claws T1c and T2c are formed at the tip of T2a. Then, as shown in FIG. 11, the lower end portion of the rigid body KF that supports the side wall portion 13d of the light guide housing member 13 is locked by the locking claws T1c and T2c of the locking portions T1a and T2a. The surfaces T1b and T2b are in pressure contact with the inclined surface of the protruding portion 30P of the light guide 30, and the side surface 30Sa of the light guide 30 facing the support surface 13f of the light guide housing member 13 by this pressure contact faces the support surface 13f. They are placed in contact with each other.

<About rigid bodies>
The rigid body KF will be described. The rigid body KF efficiently transmits the heat of the circuit board 16 that receives the heat of the light emitting body 40 of the light source unit La to the heat radiating member 14 through the heat conductive sheet 15. Is provided with a metal that is strongly sandwiched between the heat-dissipating member 14 or a metal-like rigidity, and has a shape other than that described above, and has a first mounting reference for sandwiching it as shown in FIG. A first plane portion KF3 , a second plane portion having a second attachment reference extending from the first plane portion KF3 along the longitudinal direction of the light guide 30, and a third plane portion are formed.

<Relieving warpage of light guide and light guide housing member>
As described above, the light guide housing member 13 (13a, 13b) and the light guide holding member T (T1, T2) constituting the light guide support means are formed as separate members, as shown in FIG. The light guide body holding member T (T1, T2) is held by holding the groove side wall portion 13d of the light guide housing member 13 together with the rigid body KF by the locking claws T1c, T2c of the locking portions T1b, T2b. The groove side wall portion 13d of the body housing member 13 is held by the rigid body KF and is corrected along the reference plane of the rigid body KF, and the lateral warping of the light guide body housing member 13 is eliminated. At the same time, the contact surfaces T1b, T2b of the light guide holding member T (T1, T2) are in surface contact with the side surface 30Sa of the light guide 30 and the support surface 13f forming the support curved surface of the light guide housing member 13. The projecting portion 30P of the light guide 30 is pressed. The contact surfaces T1a and T2a are formed so as to extend in the longitudinal direction together with the protrusion 30P of the light guide 30 and receive the pressing force of the locking portions T1b and T2b regardless of the shape of the light guide 30. By the contact, the light guide 30 is corrected in parallel along the reference plane of the rigid body KF described later, and the warp in the vertical direction of the light guide housing member 13 is eliminated.

<Arrangement of light emitter and light guide>
Next, it supplements regarding arrangement | positioning of the light-emitting body facing a light guide. As shown in FIGS. 16 to 18, an end face 30 </ b> L that captures light, a diffuse reflection surface 32 that diffuses and reflects light captured from the end face L, and an irradiation surface (R: FIG. 2) that diffuses and reflects light by the diffuse reflection surface 32. The arrangement of the light guide 30 including the light emitting surface 33 that emits toward the reference) and the light emitter 40 facing the at least one end surface 30L of the light guide 30 will be described. As shown in FIG. 16B, the light exit surface 33 of the light guide 30 is formed with a circumferential surface (radius r), and the diffuse reflection surface 32 is the center P1 of the circle forming the circumferential surface (radius r). The light emitter 40 disposed on the circuit board 16 at a position where the optical axis normal line hx exiting from the light exit surface 33 is formed and mounted on the circuit board 16 is circular on the optical axis normal line hx of the diffuse reflection surface 32. The light emitter 42 is disposed at the first light emitter attachment position P2 displaced toward the light exit surface 33 with respect to the center P1 of the light source, and the second light emitter attachment position P3 displaced toward the diffuse reflection surface 32 with respect to the center P1 of the circle. A light-emitting body 41 is disposed on the surface. Further, the first light emitter mounting position P2 and the second light emitter mounting position P3 are formed on the circumferential surface (radius r) forming the light emitting surface 33 with the diffuse reflection surface 32 as a position reference as shown in FIG. The center position is set to Ld0, the first light emitter mounting position P2 where the light emitter 42 is disposed is set to Ld1, and the second light emitter mounting position P3 where the light emitter 41 is disposed is set to Ld2.

In addition, as shown in FIG. 18, by arranging the light emitter 42 between the center of the circle formed by the circumferential surface and the light exit surface, the light quantity at both ends of the light guide is compared with the light quantity at the center part. It is possible to obtain a light amount distribution that is optimal for the illumination device mounted on the optical reduction system image reading device described above. Also, as shown in FIG. 16 and FIG. 17, by configuring with two light emitters 41, 42, the light quantity is increased nearly twice, and the light quantity at both ends of the light guide is made higher than the light quantity at the central part. In addition to obtaining an optimal light amount distribution for an illumination device mounted on an optical reduction system image reading device, an image reading device equipped with a so-called sheet-through mode that reads a document while automatically feeding it with brighter illumination. It is optimal for the device and can increase the image reading speed.

Further, the position of the second light emitter 41 positioned with respect to the first light emitter 42 as the position reference is adjustable so that the position of the light emitter can be finely adjusted with respect to the deterioration of the amount of light accompanying the temporal change of the light emitter. As a result, the spectral characteristics can be brought into an initial appropriate state.

<Positioning of the light emitter facing the light guide>
Next, it supplements regarding positioning of the light-emitting body facing a light guide. As shown in FIGS. 7 and 9, the light guide 30 and the circuit board 16 are both supported by the same rigid body KF, and their positional relationship is properly maintained, and the diffuse reflection surface 32 of the light guide 30 is the first of the rigid bodies KF. The circuit board 16 is held at the third position d3 that is positioned from the second plane part KF6 having two mounting references, and the circuit board 16 sets the first mounting reference based on the plane of the second plane part KF6 from the second plane part KF6. A positioning structure in which the light emitter 40 is disposed at a second position d2 facing the reference position d4 of the one end face 30L of the light guide 30 with respect to the first position d1 positioned with respect to the first flat surface portion KF3 provided. It has become. That is, the reference position d4 of the light guide is determined by positioning the diffuse reflection surface 32 of the light guide 30 from the second plane portion KF6 having the second attachment reference of the rigid body KF to the third position d3. At the same time, the circuit board 16 on which the light-emitting body 40 is mounted is mounted on the circuit board 16 by mounting the circuit board 16 at a predetermined position of the first plane portion KF3 having the first mounting reference with respect to the plane of the second plane portion KF6. The light emitter 40 is disposed at the second position d2 facing the one end face 30L of the light guide 30, and the light emitter attachment reference position d2 and the light guide attachment reference position d4 can be easily matched. The variation in the mounting position of the light emitter facing the end face of the light guide (position relative to the normal direction of the optical axis) can be minimized, and in addition to adjusting the predetermined gap between the light guide and the light emitter, illumination spots Can be suppressed.

Further, as shown in FIG. 8, a circuit board 16 is provided on the first flat surface portion KF3 of the rigid body KF having a first attachment reference for determining the attachment position of the light source unit La and a second attachment reference for determining the attachment position of the light guide unit. Positioning portions KFa and KFb are formed, and the circuit board 16 is provided with positioning support portions (16a and 16b) supported by the positioning portions KFa and KFb. The positioning support portions (16a and 16b) of the circuit board 16 are simply provided. By simply attaching to the positioning parts KFa and KFb with the light guide attached as a reference, the light emitter attachment position (position relative to the optical axis normal direction) facing the end face of the light guide can be adjusted without variation. Device assembly can be significantly improved.

<Gap retention between light guide and light emitter by reflector>
First, it supplements about the gap maintenance of a light guide and a light-emitting body. As shown in FIG. 9A, an end surface 30L that captures light, a diffuse reflection surface 32 that diffuses and reflects light captured from the end surface 30L, and an irradiation surface (R: FIG. 2) that diffuses and reflects light by the diffuse reflection surface 32 The illuminating device 9 including the light guide 30 provided with the light emitting surface 33 that emits the light toward the reference) and the light emitting body 40 facing at least one end face 30L of the light guide 30 emit light from the light emitting body 40. Is provided with a reflector 49 having reflection surfaces 49a and 49b that reflect the light toward the one end surface 30L of the light guide 30, and the light guide 30 has a protruding piece 30N that abuts the reflector 49 on the one end surface 30L. 40 is attached to the circuit board 16 on which the light emitter is mounted, and the reflector 49 is sandwiched between the projecting piece 30N of the light guide 30 and the circuit board 16 and held at a predetermined interval between the light emitter 40 and the light guide 30. By doing a reflex The can define a gap between the light emitter and the light guide body, it is not a predetermined gap between the light emitter and the light guide fluctuates, it is possible to suppress lighting spots. By using this illumination device as a light source unit of the image reading device, no unevenness in the amount of light occurs in the read image.

Further, the light guide 30 is formed with a protruding piece 30N in contact with the reflector 49 on one end face 30L thereof, the light emitter 40 is mounted and attached to the circuit board 16, and the reflector 49 is connected to the protruding piece 30N of the light guide 30 and the circuit. By sandwiching the substrate 16 and holding the light emitter 40 and the light guide 30 at a predetermined interval, the protrusion of the light guide supports the reflector plane over a wide area, and the light emitter is mounted via the reflector. The circuit board and the light guide can be reliably positioned and held.

<About the holding spring>
In addition, a holding spring member 48 that sandwiches the reflector 49 between the protruding piece 30N of the light guide 30 and the circuit board 16 is provided. As described above, the holding spring member 48 includes the heat radiation member 14 that screws the circuit board 16 on which the light emitting body 40 is mounted to the unit frame 11 via the heat-resistant sheet 15, and the light guide supported by the unit frame 11. The light guide body holding member 13 that forms the light emitter housing section that houses the body 30 is held between the protruding pieces 30N of the light guide body 30 housed in the light guide body holding member 13. The holding spring member 48 holds the circuit board 16 and the light guide 30 in pressure contact with the reflector 49, thereby holding the gap between the light emitter 40 and the light guide 30 that is a cause of illumination unevenness constant. I can do it.

Circuit board 16 that mounts the light emitting element is arranged at a gap between the entrance surface 30L of the light emitting surface and the light guide 30. This gap is preferably in the range of 0.1 millimeters to 0.55 millimeters. FIG. 9 shows an arrangement structure in a state where the light emitters 40 (41, 42) are mounted on the circuit board 16. The light emitter 40 (41, 42) is composed of a planar light emitting element, and is composed of a white LED. Further, in order to increase the total amount of light, a similar light emitter 40 (41, 42) may be disposed in place of the reflecting plate 50 on the other end face 30R. Further, in this case, the first light emitter 41 and the second light emitter 42 receive light from the incident surface 30 </ b> L of the light guide 30 from different positions between the reflection surface 32 and the emission surface 33. At the same time, the first light emitter 41 and the second light emitter 42 are arranged at a distance from each other in the outgoing optical path direction (indicated by an arrow hx in FIG. 5) from the outgoing surface 33 toward the reading surface R.

In the embodiment in which the gap between the light emitter and the light guide is defined by the reflector, the plane of the circuit board on which the light emitter is mounted is formed on one of the left and right planes of the reflector, and the other surface is formed by one end surface of the light guide. The planes are in direct contact with each other, but the following structures may be used.

One of the structures is a structure in which a thin insulating mylar is sandwiched between the reflector and the circuit board on which the light emitter is mounted, because the reflector surface is coated with a metal film with good reflection efficiency such as aluminum and silver. Further, a structure in which a thin light-shielding mylar is sandwiched in order to suppress variation in light of the light emitters narrowed down by the reflector may be employed.

Moreover, although each surface contact | abutted with a reflector is formed in the plane, it does not need to be a plane. For example, when one of the abutting surfaces has an uneven shape, the other may have an inverted uneven shape. Further, when one of the abutting surfaces has a curved surface shape, the other may have an inverted curved surface shape.

In addition, when the light irradiation surface of the light emitter mounted on the circuit board is wide and flat, the light emitter itself may be in contact with the reflector.

Moreover, even if the reflector itself is a structure integrally formed as a part of the light emitter or the light guide, the gap between the light emitter and the light guide may be defined by the reflector of the present invention.

Further, in the above-described embodiment, the light guide is arranged at one end of the light guide and the reflection plate serving as a pseudo light source is arranged at the other end. The same applies to the other end of the light guide to increase the absolute light quantity. When the light emitter is arranged in this structure, the reflector is naturally arranged on the other surface of the light guide.

The circuit board 16 on which the light emitting element is mounted is disposed with a gap d between the light emitting surface and the incident surface 30L of the light guide 30. The gap d is preferably in the range of 0.1 millimeters to 0.55 millimeters. FIG. 9 shows an arrangement structure in a state where the light emitters 40 (41, 42) are mounted on the circuit board 16. The light emitter 40 (41, 42) is composed of a planar light emitting element, and is composed of a white LED. Furthermore, in order to increase the total amount of light, a similar light emitter 40 (41, 42) may be disposed instead of the reflective paint on the other end surface 30R. Further, in this case, the first light emitter 41 and the second light emitter 42 receive light from the incident surface 30 </ b> L of the light guide 30 from different positions between the reflection surface 32 and the emission surface 33. At the same time, the first light emitter 41 and the second light emitter 42 are arranged at a distance from each other in the outgoing optical path direction (indicated by an arrow hx in FIG. 5) from the outgoing surface 33 toward the reading surface R.

[Other Embodiments of Lighting Device]
Next, another embodiment of the above-described lighting device will be described. 18A and 18B are diagrams for explaining the positional relationship between a light emitter and a light guide in a light source unit according to another embodiment corresponding to FIG. 16, where FIG. 18A is a side view, and FIG. 18B is one end of the light guide. FIG. 4C is a plan view showing the position of the light emitter relative to the light guide viewed from the light emitter side, and FIG. 5C is a plan view showing the position of the light emitter viewed from the other end side of the light guide. The difference from the light source unit shown in FIG. 16 is that the light emitting body 40 is composed of one light emitting element or two light emitting elements. The basic functions are almost the same.

In this embodiment, as shown in FIG. 18A, in this embodiment, a light emitting and emitting body 40 composed of one light emitting element facing the incident surface 30L of the light guide 30 with a certain gap is provided. The light emitting body 40 is disposed at the light emitting source position P2 shown in FIG. 17 described above. The spectral characteristics at that time will be described later with reference to FIG. As shown in FIG. 16, only one light source unit that is received in a pair before and after the sub-scanning direction with respect to the center of the reading surface R is displayed as shown in FIG.

[Spectral characteristics of lighting equipment]
Next, the spectral characteristics of the illumination device in the image reading apparatus of the present invention will be described based on the spectral characteristics diagram of FIG. In the figure, the spectral characteristics indicated by P1 to P4 indicate the spectral characteristics obtained when the light emitting and emitting body 40 is disposed at the positions P1 to P3 shown in FIG. First, the spectral characteristic indicated by P1 indicates the spectral characteristic obtained when the light emitting element 40 composed of one light emitting element (white LED) is arranged at the position P1 shown in FIG. 17, and the spectral characteristic indicated by P2. Shows the spectral characteristics of the other embodiment shown in FIG. 18 obtained when the light emitting body 40 is arranged at the position P2 shown in FIG. 17, and the spectral characteristics shown by P3 are the light emitting body 40. Is a spectral characteristic obtained when the lens is arranged at the position P3 shown in FIG. The spectral characteristic indicated by P4 is obtained when the light emitting element 40 (41, 42) composed of two light emitting elements (white LEDs) is arranged at the positions P2 and P3 shown in FIG. The spectral characteristics of the first embodiment shown in FIGS. Looking at the spectral characteristics, since the illumination device of the image reading apparatus having the contact optical system described above requires almost uniform spectral characteristics, light emission and emission composed of one light emitting element is required. An illuminating device having ideal spectral characteristics can be obtained by arranging the body 40 at the position P1 shown in FIG. On the other hand, in the case of an illumination device of an optical reduction system image reading device that is affected by the cosine fourth law by a condensing lens, the light amount distribution needs to be higher at both end portions than at the central portion. When reading is possible even when the total light quantity is relatively low, an illuminating device having ideal spectral characteristics by disposing the light emitting and emitting body 40 composed of one light emitting element at the position P2 shown in FIG. 17 and the light emitting element 40 (41, 42) composed of two light emitting elements is positioned at the position P2 shown in FIG. The illumination device having ideal spectral characteristics can be obtained by arranging the second light emission source 42 at the position P1 and the first light emission source 41 at the position P3.

[Configuration of image reading control system]
Next, an outline of a control system for reading a document image in the image reading apparatus shown in FIG. 1 will be described with reference to FIG. FIG. 20 is a functional block diagram showing a control system for reading a document image in the image reading apparatus. In FIG. 20, a portion surrounded by a two-dot chain line corresponds to the reading carriage 6 and is surrounded by a thin line. The portion corresponds to the control board S provided in the image reading unit A. The operation of the image reading apparatus by each basic functional block is as follows. The control unit CPU of the control board S drives the motor driving means S-MC, the light source lighting means S-La, and the sensor driving means S-CCD. Then, the sensor driving means S-CCD causes the line sensor 8 to read the original sheet. In other words, with the reading carriage 6 moved or stopped as necessary by the motor driving means S-MC, the original sheet is illuminated while the light emitting body 40 is appropriately turned on by the light source lighting means S-La, and the reflected light from the original. Is imaged on the line sensor 8 and photoelectrically converted to accumulate charges. The output signal from the sensor 16 is amplified by the amplifier circuit AMP and then converted into a digital image signal by the A / D converter. The image signal digitized by the A / D converter is subjected to image processing such as shading correction, digital gain adjustment, and digital black correction using shading data stored in the RAM in the image processing means. Thereafter, the digital image signal is stored in a line buffer and transferred to an external device such as a personal computer PC via an interface. These are all performed by the control unit PC controlling each functional block based on an instruction from the driver means of the external device.

[Light source control configuration]
The control of the illumination unit 9 by the light source lighting means S-La will be described. As shown in FIG. 1, the first light guide 9a and the second light guide 9b irradiate the reading surfaces R of the first platen 2 and the second platen 3 with light, and use the diffusely reflected light reflected from the read document. doing. The first light guide 9a and the second light guide 9b of the illumination unit 9 are not necessarily composed of two light emitters 40 as shown in FIG. 16, but are composed of one light emitter 40 as shown in FIG. Alternatively, although not shown, it may be composed of three or more light emitters 40. Incidentally, by increasing the number of light sources and increasing the overall illumination light quantity, in particular, the speed of the original traveling on the second platen 3 is increased in order to increase the reading speed in the original feeding unit B described later, and the reading of each reading line is increased. Even if the time is shortened, a sufficient amount of reading can be secured as the product of the amount of illumination light and the reading time, and high-speed reading using the document feeding unit B can be performed.

Actually, the carriage 6 is stopped below the second platen 3 with respect to the reading speed at which the carriage 6 is moved along the original placed on the first platen 2 for reading, and the original conveyed on the second platen 3 is read. The reading speed for reading is increased. For this reason, it is preferable that the amount of light applied to the original is higher than the amount of light used for reading using the first platen 2.

Therefore, not only the control for simultaneously lighting the first light guide 9a and the second light guide 9b but also the first light guide 30a is located on the second platen 3 when the carriage 6 is located on the first platen 2. Sometimes, a control method of lighting the first light guide 9a and the second light guide 9b is also possible.

<Other embodiments>
The light guide described above has a light emitter that emits light on one end side and a reflector that is a pseudo light source on the other end, but a reflector that also becomes a pseudo light source on the other end. Instead of this, a light-emitting body serving as a light source that directly emits light may be arranged. In this case, the trumpet shape of the light guide is symmetrical with respect to the central portion of the light guide formed also on the other end side. By doing so, an illumination device similar to the above-described embodiment can be implemented.

[Industrial applicability]
The illumination apparatus according to the present invention can be used for apparatuses other than the above-described image reading apparatus. For example, the illumination apparatus can be used as an illumination apparatus for optical devices such as an optical microscope, a magnifying projector, and a projector, or a general household illumination apparatus. I can do it.

A Image reading unit B Document feeding unit T Light guide holding member (light guide support means)
T1b Contact surface T2b Contact surface T1c Locking claw T2c Locking claw KF Rigid body 9 Illuminating device 13 Light guide housing member (light guide support means)
13a Groove part 13c 1st side wall part 13d 2nd side wall part 13e Bottom part 13f Support surface 30 Light guide 30L Incident surface 30S 1st, 2nd side surface 32 Reflective surface 33 Output surface 30P Projection part 40 Light emitter (light source)

Claims (3)

A light emitter;
A light guide that guides light of the light emitter along an illumination line direction and illuminates the illumination line area as linear light; and
A light guide support member for supporting the light guide;
A lighting device comprising:
The light guide is
In the rod shape extending in the longitudinal direction,
An incident surface on which at least one of both ends faces the above-described light emitter and enters light;
First and second side surfaces extending in the longitudinal direction opposite to each other that reflect light incident from the incident surface in the longitudinal direction;
A reflective surface that reflects the reflected light reflected from the first and second side surfaces in a direction intersecting the longitudinal direction;
And forming an exit surface that emits the reflected light reflected by the reflective surface as illumination light, and
A projecting portion projecting from at least one of the first and second side surfaces and extending along a longitudinal direction;
The protrusion is
Extending in a longitudinal direction from a projecting formation position spaced a predetermined distance in the longitudinal direction from an end surface forming an incident surface facing the light emitter,
The inner surface forms a reflective surface with the first and second side surfaces,
Said first, second aspect, Ri formed by forming sequentially the wide shape of protruded position of the projecting portion toward the incident surface,
The reflective surface is
The incident surface side is formed as one end toward the other end,
One end thereof is set on the other end side from the protrusion forming position of the protrusion,
In addition, the illumination device is formed by forming a reflection pattern in which the width in the direction orthogonal to the longitudinal direction is sequentially enlarged from one end to the other end . The first of the light guide body, the second aspect, the curved portion which connects at least the curved portion and the reflective surface of the light guide with the second curvature first with a curvature to articulate an emission surface of the light guide It is formed by a curved surface consisting of a width of the reflective surface lighting device according to claim 1 comprising the second curvature magnitude altered form in accordance with the width position in the longitudinal direction. An illumination device for irradiating a subject with light;
An image reading sensor that receives reflected light from the subject;
An image reading control device for controlling the image reading sensor,
The lighting device, an image reading apparatus according to claim it is a lighting apparatus according to the claim 1 or 2.