JP5544999B2 - Illumination device and image reading device - Google Patents

Description

  The present invention relates to an illuminating device and an image reading device having the illuminating device, and more particularly to an illuminating device and an image reading device used for a facsimile, a copier, a scanner, and the like.

  In general, a sidelight type illumination device used in an image reading device or the like is composed of a light source such as an LED and a light guide that transmits light, and guides light emitted from the light source to be installed facing the light source. The light is introduced from the light incident surface into the light guide. The light guide has a scattering region for diffusing and reflecting incident light and an emission part provided at a position facing the scattering region, and guides the incident light in the longitudinal direction (main scanning direction) of the light guide. Light is emitted and scattered from the scattering region and emitted from the emitting portion. The linear light emitted from the light guide illuminates the image reading target area.

  In the illumination device of Patent Document 1, a plurality of light sources installed on the end face of the light guide and the end of the light guide are covered with a reflection sheet, so that the light emitted from the light source is incident on the end of the light guide. The light emitted at an angle that is not reflected is folded back by the reflection sheet. This increases the amount of light incident on the light guide.

JP 2002-42529 (pages 3 to 4)

  However, when a plurality of light sources are arranged side by side as in Patent Document 1, a part of light emitted from one light source hits a lens or package of an adjacent light source, so that light loss due to refraction, scattering, and absorption occurs. It was happening. Further, by covering all the light sources together with the reflection sheet, the light reflected by the reflection sheet hits another light source, and the loss is larger. Furthermore, since the number of times the light is reflected by the reflection sheet increases by providing a large space surrounded by the reflection sheet, the amount of light absorbed by the reflection sheet increases. As a result, there is a problem in that the amount of light incident on the light guide is reduced, and the illumination efficiency for illuminating the image reading target area is reduced.

  The present invention has been made to solve such a problem, and an illumination device that efficiently enters light emitted from a light source into a light guide and irradiates a reading region with a sufficient amount of light for image reading. The purpose is to provide.

The present invention is an illuminating device that irradiates reading light to a reading region to be read, and includes a light source having a light emitting portion that is a region from which light is emitted, and a regular reflection surface that totally reflects light on the inner wall. A reflection member that has a through-hole, and is disposed in a state in which the optical axis of light emitted from the light-emitting portion passes through the inside of the through-hole, a light incident portion, and a light emission portion; A light guide that propagates through the inside and emits light from the light emitting portion toward the reading region, the light source abuts on one opening of the through hole, and the light incident portion on the other opening When the overlapping of the light source, one opening of the through hole, the other opening of the through hole, and the light incident portion is viewed from the direction of the optical axis, the one opening of the through hole is in the light source. wherein the shape of one opening of the through hole coincides with the outer shape of the light emitting portion, and a is Lighting apparatus other opening of the through hole is characterized in that in the region of the light incident portion.

  As described above, the illumination device and the image reading device according to the present invention provide a pipe-shaped member having a mirror surface between the light source and the incident surface, thereby suppressing the loss of light incident on the light guide and improving the illumination efficiency. A good lighting device can be obtained.

1 is a schematic perspective view of an image reading apparatus according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the image reading apparatus in FIG. 1 at a position along the line AA. 1 is an assembly diagram of an image reading apparatus according to Embodiment 1 of the present invention. It is a schematic diagram explaining the light propagation of the light guide of the image reading apparatus which concerns on Embodiment 1 of this invention. It is an assembly drawing in the edge part of the light guide of the illuminating device which concerns on Embodiment 1 of this invention. It is a schematic diagram explaining the edge part of the light guide of the illuminating device which concerns on Embodiment 1 of this invention. It is a schematic diagram explaining the hole diameter of the through-hole of the reflection member of the illuminating device which concerns on Embodiment 1 of this invention. It is a schematic diagram explaining the optical path in case the hole diameter of the through-hole of the reflection member of the illuminating device which concerns on Embodiment 1 of this invention is smaller than the light emission part of a light source. It is a schematic diagram explaining the optical path when the hole diameter of the through-hole of the reflection member of the illuminating device which concerns on Embodiment 1 of this invention is larger than the thickness of a light guide. It is a schematic diagram explaining the optical path in case the hole diameter of the through-hole of the reflection member of the illuminating device which concerns on Embodiment 1 of this invention is larger than the light emission part of a light source. It is a schematic diagram explaining the optical path of the image reading apparatus which concerns on Embodiment 1 of this invention. 1 is a circuit block diagram of an image reading apparatus according to Embodiment 1 of the present invention. It is a schematic diagram explaining the optical path of the image reading apparatus using the reflective light guide which concerns on Embodiment 2 of this invention. It is a schematic diagram explaining the light propagation of the reflective light guide of the image reading apparatus according to Embodiment 2 of the present invention. It is a schematic diagram explaining the optical path of the image reading apparatus using the refractive light guide which concerns on Embodiment 2 of this invention. It is a schematic diagram explaining the light propagation of the refraction type light guide of the image reading device concerning Embodiment 2 of the present invention. It is a schematic diagram explaining the light loss of the light source of the image reading apparatus which concerns on Embodiment 3 of this invention. It is a schematic diagram explaining the optical path when a reflecting member is installed in the light source of the image reading apparatus according to Embodiment 3 of the present invention. It is a schematic diagram explaining the cylindrical reflection member of the illuminating device which concerns on Embodiment 4 of this invention. It is sectional drawing along the DD line of FIG. It is a schematic diagram explaining the clearance gap produced when a bullet-type light source is installed in the square tube reflecting member of the illuminating device which concerns on Embodiment 4 of this invention. It is sectional drawing along the EE line of FIG. It is a schematic diagram explaining the square cylinder reflection member of the illuminating device which concerns on Embodiment 5 of this invention. It is sectional drawing along the FF line of FIG. It is a perspective view of the metal reflective member of the illuminating device which concerns on Embodiment 6 of this invention. It is a schematic diagram explaining the optical path when a light source is installed in the metal reflective member of the illuminating device which concerns on Embodiment 6 of this invention. It is a perspective view of the resin reflective block of the illuminating device which concerns on Embodiment 7 of this invention. It is a perspective view of the division | segmentation reflection block of the illuminating device which concerns on Embodiment 8 of this invention. It is a schematic diagram explaining the state which piled up the two division | segmentation reflection blocks of the illuminating device which concerns on Embodiment 8 of this invention. It is a schematic diagram explaining the optical path when a filter is inserted between the light guide and the light source of the illumination device according to Embodiment 9 of the present invention. It is a schematic diagram explaining the state which integrated the holder and reflection member of the illuminating device which concerns on Embodiment 10 of this invention. It is a schematic diagram explaining the state which connected two members of FIG. 26 of the illuminating device which concerns on Embodiment 10 of this invention. It is a schematic diagram explaining the state which joined the board | plate material to the reflection member of the illuminating device which concerns on Embodiment 11 of this invention. It is a schematic diagram of the board | plate material joined to the reflection member of the illuminating device which concerns on Embodiment 11 of this invention. It is sectional drawing along the II line | wire of FIG. It is sectional drawing along the JJ line of FIG. It is a schematic diagram explaining an optical path when the internal diameter of the through-hole of the reflection member of the illuminating device which concerns on Embodiment 12 of this invention is made wider on the light guide side rather than the light source side. It is a schematic diagram explaining an optical path when the internal diameter of the through-hole of the reflection member of the illuminating device which concerns on Embodiment 12 of this invention is made wider on the light source side rather than the light guide side. It is a schematic diagram explaining metal vapor deposition in case the regular reflection surface of the reflection member of the illuminating device which concerns on Embodiment 12 of this invention does not have an inclination. It is a schematic diagram explaining metal vapor deposition in case the regular reflection surface of the reflection member of the illuminating device which concerns on Embodiment 12 of this invention has an inclination. It is a schematic diagram explaining the state which connected the regular reflection surface of the reflection member of the illuminating device which concerns on Embodiment 13 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In each figure, the same or similar components are denoted by the same reference numerals.

Embodiment 1 FIG.
Hereinafter, the configuration of the image reading apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic perspective view of an image reading apparatus (also referred to as a contact image sensor or CIS) including an illumination device according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is an exploded view of the image reading apparatus of FIG. 4 is a schematic view of an end portion of a light guide used in the illumination device shown in FIGS. 1 to 3, and is a cross-sectional view of the light guide 2 shown in FIG. 1 cut along an XZ plane.

  Here, XYZ orthogonal coordinates shown in the figure will be described with reference to FIG. The Y-axis direction is the left-right direction on the paper surface, corresponds to the feed direction of the document 1, and is also called the sub-scanning direction. The X-axis direction is orthogonal to the Y-axis direction and is the depth direction of the paper surface, and is also called the main scanning direction. Further, the Z-axis direction is orthogonal to both the X-axis direction and the Y-axis direction, and is the vertical direction of the paper surface, which is also called the reading depth direction. Thus, the main scanning direction is defined as the X-axis direction, the sub-scanning direction is defined as the Y-axis direction, and the reading depth direction is defined as the Z-axis direction.

  Referring to FIG. 1, in an image reading apparatus according to Embodiment 1 of the present invention, a reading optical system (rod lens array) 5 extending in the X-axis direction is arranged in a housing 9, and this is arranged on both sides thereof. Similarly, a light guide 2 that extends in the X-axis direction is provided so as to sandwich the gap. Both ends of the light guide 2 are light incident portions 13, and a light source 11 is provided in the vicinity thereof. The upper surface of the housing 9 is covered with the transparent body 3, and the document 1 is placed directly above the transparent body 3 or at a position separated by a predetermined distance. On the other hand, a sensor substrate 6 having a sensor IC 4, a signal processing IC (ASIC (Applied Spec IC Integrated Circuit)) 7, and a connector 8 is disposed on the lower surface of the housing 9.

The light from the light source 11 is transmitted through the light guide 2 and is emitted from the upper surface of the light guide 2. The light emitted from the light guide 2 reaches the image reading region 30 (the portion indicated by the broken line in FIGS. 1 to 3) on the document 1 and is reflected, passes through the reading optical system 5, and passes through the reading optical system 5. Reading is performed by the sensor IC 4 provided below.
The light guide 2, the reading optical system 5, and the sensor IC 4 have a length equal to or greater than the effective reading width (effective reading width in the main scanning direction) of the document 1. When the reflected light is read by the sensor IC 4, the document 1 and the housing 9 relatively move in the Y-axis direction (sub-scanning direction). As a result, the image data of the document 1 is read. The read image data is sent to the signal processing IC 7 for correction processing and the like.

  Each component of the image reading apparatus will be described in detail.

  The document 1 is, for example, a read medium (irradiated body) that is image information such as a photograph or a general document.

The light guide 2 is a rod-like body extending in the X-axis direction (main scanning direction), and is formed of, for example, a quartz rod. The cross section of the light guide 2 is formed of a rectangular light guide 20 and a condensing lens 21 having a shape obtained by dividing a cylinder into two parts with reference to FIG.
The condenser lens 21 is provided so as to cover a part of the upper surface of the light guide path 20. The curved surface portion of the condenser lens 21 is a light emitting portion 31, which is a region where the light inside the light guide 2 is emitted to the outside. The light emitting unit 31 is formed in a shape in which the image reading area 30 on the document 1 is irradiated with the emitted light.
A light scattering layer (light scattering region) 32 is formed at a position facing the light emitting portion 31 on the lower surface of the light guide path 20. The light scattering region 32 is applied to a part of the light guide 2 (region where the light scattering region is formed) by applying a light reflecting paint such as a white pigment, rough surface processing, sawtooth prism processing, or pyramid shape. It can be formed by performing an emboss shape processing. In particular, when prism shape processing or emboss shape processing is used, it is possible to integrally mold the light guide 2 at the same time. When the light guide 2 does not have a flat region like a columnar (rod type) light guide, a part of the outer periphery may be shaved and flattened to form the light scattering region 32.

  The transparent body 3 forms a transport path for the document 1. Also, it plays a role of preventing foreign matters from entering the image reading apparatus, and is made of a transparent resin such as acrylic or polycarbonate, or a transparent glass material.

  The reading optical system 5 is provided so that the reflected light reflected from the image reading area 30 of the document 1 is incident from the optical axis direction of the reading optical system 5 and converges the incident light.

  The sensor IC 4 is a sensor that receives the light converged by the reading optical system 5 and photoelectrically converts it to output an electrical signal. The sensor IC 4 is equipped with a photoelectric conversion unit composed of a semiconductor chip or the like, and other driving circuits. . Referring to FIG. 3, sensor IC 4 is mounted on sensor substrate 6 together with other electronic components.

  The signal processing IC (ASIC) 7 processes and outputs the photoelectric conversion output of the sensor IC 4, and digitizes the output from the signal processing circuit that performs signal processing in conjunction with the CPU and RAM, and the sensor IC 4. Consists of analog-digital conversion circuit. The signal processing IC 7 is also placed on the sensor substrate 6.

  An external connector 8 is also placed on the sensor substrate 6. The external connector 8 is used as an interface for input / output signals including the photoelectric conversion output of the sensor IC 4 and the signal processing output of the ASIC 7.

  The housing 9 is provided so as to accommodate and hold the light guide 2, the reading optical system 5, and the sensor substrate 6, and is formed of metal or plastic.

  The light source 11 is composed of an LED chip or the like, and usually emits visible light, infrared light, ultraviolet light, or the like. The light source 11 is disposed in the vicinity of the light incident portions 13 at both ends of the light guide 2.

The configuration of the end portion of the light guide 2 will be described in detail with reference to FIG.
The light source 11 is mounted on the light source substrate 12 together with an electrode pattern to be driven.
The light source substrate 12 is fixed to both ends of the light guide 2 by a light source holding part (holder or LED holder) 10. At this time, the light source substrate 12 is positioned so that the light source 11 is positioned in the vicinity of the light incident portion 13 of the light guide 2 and the optical axis of the light emitted from the light source 11 is perpendicularly incident on the light incident portion 13 of the light guide 2. Is fixed. The light source 11 may be provided at both ends of the light guide 2 or may be provided only at one end. A plurality of light sources 11 may be provided at one end.

  A power connector 41 is placed on the holder 10. The power connector 41 is a terminal for driving the light source 11, and the power is supplied from outside the lighting device.

  A reflection member 14 is provided between the light source 11 and the light incident portion 13 of the light guide 2. The reflection member 14 is a cylindrical body (pipe shape) having a through hole 16 and is installed at a position where the optical axis of the light source 11 passes through the through hole 16. At this time, referring to FIG. 4, the periphery of the opening on the light source 11 side of the through hole 16 is the first opening 17, and the periphery of the opening on the light incident portion 13 side of the light guide 2 is the second opening 18. . The first opening 17 is in contact with the light source 11, and the second opening 18 is in contact with the light incident part 13 of the light guide 2. The contact between the first opening and the light source 11 will be described more specifically. The light source 11 is inscribed in the opening of the through hole 16, and the light source substrate 2 is in contact with the end of the reflecting member 14.

FIG. 5 is an assembly view of the end portion of the light guide 2. FIG. 6 is a schematic view showing a state where the members shown in FIG. 5 are assembled.
The opening of the through hole 16 of the reflecting member 14 has the same circular shape as the outer shape of the light source 11, and a regular reflection surface 15 is provided on the inner wall surface of the through hole 16.

  The regular reflection surface 15 provided on the inner wall surface of the reflection member 14 ensures a mirror surface such as a metal vapor deposition or a metal polishing surface, and ensures a reflectance of 50% or more in a wavelength band necessary for image reading. As the reflectance of the regular reflection surface 15 is higher, the light amount loss due to reflection is smaller, and an increase in illumination efficiency can be expected. Therefore, when actually used, it is desirable to ensure that the reflectance of the regular reflection surface 15 is 85% or more.

The shape of the reflecting member 14 will be described in detail with reference to FIG.
The diameter of the through hole 16 of the reflecting member 14 is φ, the diameter of the light source 11 is λ, and the diameter of the light emitting portion 33 of the light source 11 is ψ. Moreover, the thickness of the depth direction in the position which fixes the holder 10 among the light-incidence parts 13 of the light guide 2 is set to (tau).
The light emitting unit 33 refers to a portion where light is emitted from the light source 11. For example, when an LED without a lens (surface mounted LED), a bare chip LED, or an organic EL is used as the light source 11, a region where light is emitted on the surface of the light source 11 is used as the light emitting unit 33. When the attached LED is used, the bullet portion and the lens are used as the light emitting portion 33.
At this time, the hole diameter φ of the through hole 16 of the reflecting member 14 is set to be not less than the diameter ψ of the light emitting portion 33 of the light source 11 and not more than the diameter λ of the light source 11 (equation (1)). In addition, the hole diameter φ of the through hole 16 of the reflecting member 14 is set to be equal to or smaller than the thickness τ in the depth direction of the light incident portion 13 of the light guide 2 (equation (2)).

ψ ≦ φ ≦ λ (1)

φ ≦ τ (2)

In the first embodiment, since the shapes of the openings at both ends of the through-hole 16 are the same, the hole diameter φ of the through-hole 16 is smaller than either the diameter λ of the light source 11 or the thickness τ of the light guide 2. It is necessary not to exceed this (formula (3), formula (4)).

ψ ≦ φ ≦ λ (λ ≦ τ) (3)

ψ ≦ φ ≦ τ (τ <λ) (4)

However, when the conditions of the expressions (3) and (4) are not satisfied, it can be dealt with by changing the shapes of the openings at both ends of the through hole 16. This will be described in Embodiment 12.

When the diameter of the through hole 16 of the reflecting member 14 does not satisfy the conditions of the above formulas (1) and (2), the following problems occur.
FIG. 8 shows a case where the diameter φ of the through hole 16 of the reflecting member 14 is smaller than the diameter ψ of the light emitting portion 33 of the light source 11. In this case, a part of light from the light source 11 indicated by a broken line is reflected by a surface other than the regular reflection surface 15 provided in the through hole 16 of the reflection member 14 and does not enter the light guide 2. Therefore, a loss occurs in the amount of light that irradiates the image reading area 30 of the document 1.
FIG. 9 shows a case where the diameter φ of the through hole 16 of the reflecting member 14 is larger than the thickness τ of the light guide 2. In this case, a part of the light from the light source 11 indicated by a broken line is reflected and scattered by the holder 10, and is reflected multiple times and enters the light guide 2. Therefore, as in the case of the configuration of FIG. 8, a light amount loss occurs. Even if only the regular reflection occurs with the inside of the holder 10 as a mirror surface, the light is lost due to multiple reflections before the light enters the light guide 2.
Further, FIG. 10 shows a case where the diameter φ of the through hole 16 of the reflecting member 14 is larger than the size λ of the light source 11. As for the LED assumed for the light source 11, the package is often made of a white resin, and when the package is exposed to light, a high reflectance can be expected although it is scattered. Therefore, the light incident from one end of the light guide 2 and transmitted through the inside of the light guide 2 is reflected by the package portion of the light source 11 provided at the other end of the light guide 2 and turned back. The light utilization efficiency is increased by making the light incident on 2. However, when the diameter φ of the through hole 16 of the reflecting member 14 is larger than the size of the light source 11 as shown in FIG. 10, the light transmitted through the light guide 2 is not in the package portion of the light source 11 but in the light source substrate 12 or the like. Reflected by a low reflectance member. Therefore, the amount of light is lost and the illumination efficiency is reduced.
As described above, when the diameter φ of the through hole 16 of the reflecting member 14 does not satisfy the conditions of the expressions (1) and (2), there is a problem that the amount of light is lost.

Next, operations of the illumination device according to the present embodiment and an image reading device using the same will be described.
The broken arrows in FIG. 4 indicate how light propagates around the end of the light guide 2. With reference to FIG. 4, the light emitted from the light source 11 is incident on the inside of the light guide 2 directly or after being regularly reflected by the regular reflection surface 15 of the reflecting member 14. The light incident on the light guide 2 travels in the main scanning direction (longitudinal direction, X-axis direction) while repeating total reflection inside the light guide 2 that plays a role of propagating light. Further, part of the light scattered and reflected by the light scattering region 32 provided in the light guide 2 is emitted to the outside from the light emitting unit 31 provided at a position facing the light scattering region 32.

An optical path of light emitted from the light guide 2 is shown in FIG. FIG. 11 is a cross-sectional view taken along line AA in FIG.
The light emitted from the light emitting portion 31 of the light guide 2 has a uniform luminance or intensity over the main scanning direction, is refracted by the transmission body 3 and irradiates the image reading area 30 of the document 1. The irradiation angle C of light to the image reading area 30 of the document 1 is an extension line (indicated by a broken line in FIG. 11) connecting the light scattering area 32 and the light emitting portion 31 of the light guide 2 and the light of the reading optical system 5. The angle is determined by the axis (indicated by a dashed line in FIG. 11).
The reflected light 42 reflected from the image reading area 30 of the document 1 is converged by the reading optical system 5 and received by the sensor IC 4.
The sensor IC 4 converts the received light into an electrical signal corresponding to the light intensity by photoelectric conversion (photoelectric conversion) and outputs the electrical signal. The electrical signal is subjected to signal processing by an ASIC 7 or the like mounted on the sensor substrate 6 and finally output from the external connector 8 to the outside of the image reading apparatus as an image signal of the document 1.

FIG. 12 is a block diagram of a drive circuit of the image reading apparatus.
An analog output (SO) photoelectrically converted by the light receiving unit of the sensor IC 4 is obtained at the timing of the start signal (SI) synchronized with the CIS clock signal (CLK) in synchronization with the system clock (SCLK) of the timing generator. .
The analog output (SO) is converted into a digital signal by an analog / digital (A / D) conversion circuit of the ASIC 7, and then shading correction including sample and hold, all bit correction, and the like are performed in the signal processing circuit. For digital signal correction processing, data is sampled from a RAM area storing digital signal data and a RAM area storing reference data, and is processed. The processed signal SIG is output from the external connector 8.

  As described above, according to the present embodiment, the reflecting member 14 having a through-hole 16 between the light source 11 and the light incident portion 13 of the light guide 2 and having a mirror surface on the inner surface is provided. The diameter of the through hole 16 is configured to be not less than the hole diameter of the light emitting portion 33 of the light source 11, not more than the hole diameter of the light source 11, and not more than the thickness of the light guide 2. As a result, most of the light that is not directly incident on the light guide 2 from the light source 11 is folded back by one regular reflection on the regular reflection surface 15 formed in the through hole 16 of the reflection member 14 and is incident on the light guide 2. Lighting efficiency is improved.

  Further, since the light source 11 is surrounded by the reflecting member 14 and the space between the light guide 2 and the light source 11 is narrowed, the light re-enters the light guide 2 with a small number of reflections, thereby reducing the light amount loss due to reflection. To do.

The light source 11, the through hole 16 of the reflecting member 14, and the light incident portion 13 of the light guide 2 are not limited to the shapes described above, but pass through when the illumination device according to the present embodiment is viewed from the direction of the optical axis. The hole 16, the light source 11, and the light incident part 13 should just satisfy | fill the following relationship, respectively.
The optical axis direction used below is the optical axis direction of the light source 11 and is an axis parallel to the X direction.
In the first opening 17, the opening of the through hole 16 coincides with the maximum dimension of the light source 11 or is within the maximum dimension of the light source 11 when viewed from the optical axis direction. Furthermore, when viewed from the optical axis direction, the region of the light emitting portion 33 that emits light coincides with the opening of the through hole 16 or is in the opening of the through hole 16.
In the second opening 18, when viewed from the optical axis direction, the opening of the through hole 16 coincides with the region of the light incident portion 13 of the light guide 2 or the light incident portion of the light guide 2. There are 13 areas.

  Moreover, although it has been described that the light source 11 is in contact with the opening of the through hole 16 as to how the light source 11 and the reflecting member 2 are in contact with each other in the first opening portion 17, the present invention is not limited to this. As long as the opening is closed. For example, the light source 11 may be brought into contact with the end of the reflecting member 14 so as to close the opening. Further, the light emitting unit 33 of the light source 11 may be configured to be inscribed in the opening of the through hole 16.

Embodiment 2. FIG.
Next, the configuration of the image reading apparatus according to the second embodiment of the present invention will be described with reference to FIGS.

14 and 16 are cross-sectional views of the end portion of the light guide used in the image reading apparatus according to Embodiment 2 of the present invention. FIG. 14 shows a cross section of a reflective light guide 102 that emits light to the outside using reflection, and FIG. 16 shows a cross section of a refractive light guide 202 that emits light to the outside using refraction. 13 and 15 are cross-sectional views of an image reading apparatus incorporating the light guide shown in FIGS.
The image reading apparatus according to the second embodiment of the present invention is the same as that of the first embodiment except that the light guide is different. Therefore, only differences from the first embodiment will be described below. In addition, the embodiment described below has the same effect as that of the first embodiment in addition to the effect due to the configuration unique to the present embodiment.

First, the configuration of the image reading apparatus using the reflective light guide 102 will be described.
FIG. 13 is a cross-sectional view of the image reading apparatus incorporating the reflective light guide 102 taken along the YZ plane. The two reflective light guides 102 are installed with the reading optical system 5 interposed therebetween. The illuminating device according to the present embodiment is configured to obtain a uniform illuminance distribution in the sub-scanning direction by superimposing the light emitted from the two reflective light guides 102 opposed to each other.

  Referring to FIG. 14, the reflective light guide 102 is a rod-like body having a trapezoidal cross section and extending in the X direction (main scanning direction). A reflecting surface 43 having an inclination is provided on the end surface facing the portion 113. Further, a light emitting part 131 is provided on the upper surface of the reflective light guide 102. The angle of the reflection surface 43 is based on the installation position of the reflective light guide 102 and the position of the image reading area 30 of the document 1 so that the light emitted from the light emitting unit 131 irradiates the image reading area 30 of the document 1. Adjusted. The reflective surface 43 is formed by vapor-depositing a metal such as aluminum on the surface of the reflective light guide 102.

  The light source 11 is disposed in the vicinity of the light incident portion 113 so that the direction of the optical axis, that is, the light emission direction coincides with the sub-scanning direction. In the first embodiment, the light incident portions 13 are provided at both ends of the light guide 2, and the light source 11 is disposed in the vicinity of the light incident portion 13 so that the direction of the optical axis coincides with the main scanning direction. Different.

  Between the light source 11 and the light incident portion 113 of the reflective light guide 102, the same reflective member 14 as in the first embodiment is installed.

Next, the operation of the illumination device using the reflective light guide 102 and the image reading device incorporating it will be described.
A broken line arrow shown in FIG. 14 indicates an optical path of light incident from the light incident portion 113 of the reflective light guide 102. The light incident from the light incident surface 113 propagates in the sub-scanning direction while repeating total reflection inside the reflective light guide 102, is kicked up by the reflective surface 43, and is emitted to the outside from the light emitting portion 131. The operation after the light is emitted from the reflective light guide 102 is the same as in the first embodiment.

Next, the configuration of the image reading apparatus using the refractive light guide 202 will be described.
FIG. 15 is a cross-sectional view of the image reading apparatus incorporating the refractive light guide 202 taken along the YZ plane. The two refractive light guides 202 are installed with the reading optical system 5 interposed therebetween. The illumination device according to the present embodiment is also configured to obtain a uniform illuminance distribution in the sub-scanning direction by superimposing light emitted from two opposing refractive light guides 202.

  Referring to FIG. 16, the refractive light guide 202 is a rod-like body having a trapezoidal cross section and extending in the X direction (main scanning direction). A refracting surface 44 having an inclination opposite to that of the reflective light guide 102 is provided on the end surface facing the portion 213. The angle of the refracting surface 44 is adjusted based on the installation position of the refractive light guide 202 and the image reading area 30 of the document 1 so that the light emitted from the light incident portion 213 irradiates the image reading area 30 of the document 1. The

  The light source 11 is disposed in the vicinity of the light incident portion 213 so that the direction of the optical axis, that is, the light emission direction coincides with the sub-scanning direction.

  The same reflecting member 14 as in the first embodiment is installed between the light source 11 and the light incident portion 213 of the refractive light guide 202.

Next, operations of the illumination device using the refractive light guide 202 and the image reading device incorporating the illumination device will be described.
A broken line arrow shown in FIG. 15 indicates an optical path of light incident from the light incident portion 213 of the refractive light guide 202. The light incident from the light incident surface 213 propagates in the sub-scanning direction while repeating total reflection inside the refractive light guide 202, refracts at the refracting surface 44, and exits to the outside. The operation after the light is emitted from the refractive light guide 202 is the same as in the first embodiment.

  As described above, even in the image reading apparatus using the reflective light guide 102 or the refractive light guide 202, the reflective member 14 is provided between the light source 11 and the light guide to emit light from the light source 11. Of the light, light emitted at an angle that does not directly reach the light incident portion of the light guide can be folded back by regular reflection on the inner wall surface of the through hole 16 of the reflection member 14 and can be incident on the light guide. Thereby, the light quantity which injects into a light guide increases, As a result, the illumination light quantity increases.

Embodiment 3 FIG.
The configuration of the image reading apparatus according to the third embodiment of the present invention will be described with reference to FIGS.

The third embodiment is an illuminating device in which a plurality of light sources 11 are arranged in the vicinity of the light incident portion of the light guide in the first and second embodiments, and an image reading apparatus incorporating the same.
The image reading apparatus according to Embodiment 3 of the present invention is the same as Embodiments 1 and 2 except that the number of light sources 11 and reflection members 14 provided at the end of the light guide is different. Therefore, only the differences will be described below based on the first embodiment. In addition, the embodiment described below has the same effects as those of the first and second embodiments, in addition to the effects caused by the configuration unique to the present embodiment.

FIG. 17 is a cross-sectional view of the light guide 2 shown in FIG. 1 cut along an XY plane, and two LEDs 46 with lenses 45 are installed as light sources near the light incident portion 13 of the light guide 2. . Moreover, the broken line in FIG. 17 shows the optical path of the light radiate | emitted from LED46.
When the LED 46 is turned on in a state where there are a plurality of LEDs 46 in the same space as shown in FIG. 17, the light emitted from the LED 46 is reflected and refracted by the lens 45 of the other LED 46 and is incident on the light guide 2. A component that does not reach the portion 13 is generated. Further, components that are refracted by the lens 45 and absorbed in the package of the LED 46 and components that are directly absorbed by the package of the LED 46 are also generated. As a result, the light incident efficiency to the light guide body is deteriorated.

  Therefore, when a plurality of light sources 11 are arranged in the vicinity of the light incident portion of the light guide, the reflecting member 14 is installed for each LED 46 with reference to FIG. As a result, the above-described component that deteriorates the incident efficiency of the light emitted from the LED 46 to the light guide 2 is folded back at the regular reflection surface 15 provided in the through hole 16 of the reflection member 14, and the light incident portion of the light guide 2. By guiding to 13, the incident efficiency to the light guide 2 can be improved and more efficient illumination can be performed.

Embodiment 4 FIG.
The configuration of the image reading apparatus according to the fourth embodiment of the present invention will be described with reference to FIGS.

The fourth embodiment is an image reading apparatus in which the shape of the through hole 16 of the reflecting member 14 in the first to third embodiments matches the outer shape (cross section) when the light emitting unit 33 of the light source 11 is viewed from the optical axis direction. It is.
The image reading apparatus according to the fourth embodiment of the present invention is the same as the first to third embodiments except that the reflecting member 14 is different. Therefore, only the differences will be described below based on the first embodiment. In addition, the embodiment described below has the same effects as those of the first to third embodiments in addition to the effect caused by the configuration unique to the present embodiment.

  In the present embodiment, a bullet-type light source 38 or an LED 46 with a lens 45 is used as the light source 11. In this case, the bullet portion 47 of the bullet-type light source 38 and the lens portion (collecting portion) 45 of the LED with lens become the light emitting portion 33.

The reflecting member 14 is provided with a through hole 16 whose hole shape matches the outer shape (cross section) of the light emitting unit 33 of the light source 11 when viewed from the optical axis direction. In general, the cross section of the bullet portion 47 of the bullet-type light source 38 and the lens portion (light collecting portion) 45 of the LED with lens is circular. Therefore, the reflecting member 14 is provided with a circular through hole 16 having the same size as the cross section of the bullet portion 47 and the lens 45 of the light source 11.
FIG. 19 is a schematic view of a reflective member (cylindrical reflective member) 36 having a circular through-hole 16, and FIG. 20 is a cross-sectional view taken along line DD of the cylindrical reflective member 36 shown in FIG. 19. .

  The bullet-type light source 38 and the LED 46 with the lens 45 are arranged so that the light emitting portion 33 is inscribed in the through hole 16 of the cylindrical reflection member 36.

  Next, problems when the shape of the light-emitting portion 33 of the light source 11 and the through hole 16 of the reflecting member do not match will be described.

  FIG. 21 is a schematic view of a state in which a reflection member (square tube reflection member) 37 having a square through hole 16 is arranged in the bullet-type light source 38 as viewed from the opening side of the square tube reflection member 37. A gap indicated by a hatched portion is generated between the light source 11 and the square cylindrical reflection member 37. The influence of the gap on the light incident efficiency on the light guide will be described with reference to FIG.

22 is a cross-sectional view taken along line EE in FIG. Part of the light emitted from the bullet-type light source 38 leaks outside the illumination device through the gap between the bullet-type light source 38 and the rectangular tube-shaped reflecting member 37 through an optical path as indicated by a solid line arrow in the figure. Therefore, there exists a problem that the light quantity which injects into the light-incidence part 13 of the light guide 2 reduces.
When light sources are provided at both ends of the light guide 2, a part of the light emitted from the bullet-type light source 38 provided at the other end of the light guide 2 and transmitted through the light guide 2 is shown in FIG. The light passes through the gap between the bullet-type light source 38 and the rectangular tube-shaped reflecting member 37 along the optical path as indicated by the broken arrow inside, and leaks to the outside of the illumination device. Therefore, there is a problem that the amount of light incident on the light guide 2 is reduced.

  Therefore, by making the hole shape of the through hole 16 of the reflection member 14 coincide with the cross-sectional shape of the light emitting portion 33 of the light source 11, there is no gap between the reflection member 14 and the light source 11, and between the light source 11 and the reflection member 14. Light will not leak. Thereby, the light irradiated from the light source 11 can be efficiently incident on the light guide 2.

Embodiment 5 FIG.
The configuration of the image reading apparatus according to the fifth embodiment of the present invention will be described with reference to FIGS.

In the fifth embodiment, similarly to the fourth embodiment, the image reading apparatus in which the hole shape of the reflecting member 14 in the first to third embodiments is made to match the outer shape (cross section) of the light source 11 when viewed from the optical axis direction. It is.
The image reading apparatus according to the fifth embodiment of the present invention is the same as the first to third embodiments except that the reflecting member 14 is different. Therefore, only the differences will be described below based on the first embodiment. In addition, the embodiment described below has the same effects as those of the first to third embodiments in addition to the effect caused by the configuration unique to the present embodiment.

  In the present embodiment, an LED (surface mounted LED) 39 without a lens, a bare chip LED, an organic EL, or the like is used as the light source 11.

The reflecting member 14 is provided with a through hole 16 having a shape that matches the outer shape of the light source 11 when viewed from the optical axis direction. The external shape of the surface-mounted LED 39 and the organic EL is often a square such as a square or a rectangle. Therefore, the reflective member 14 is provided with a rectangular through-hole 16 that is the same as the outer shape of the light source 11.
FIG. 23 is a schematic diagram of a reflecting member (square tube reflecting member) 37 in which the through hole 16 has a square shape, and FIG. 24 is taken along line FF of the rectangular tube reflecting member 37 shown in FIG. FIG.

  The surface-mount type LED, bare chip LED, organic EL, and the like are arranged so that the surface is in contact with the end face of the square tube type reflecting member 37.

  Next, the reason why the incident efficiency of light incident on the light guide is improved by matching the shape of the through hole 16 of the reflecting member and the light source 11 will be described.

  FIG. 24 is a schematic view of the state in which the rectangular tube-shaped reflecting member 37 is disposed on the surface-mounted LED 39 as viewed from the opening side of the rectangular tube-shaped reflecting member 37. There is no gap between the light source 11 and the square cylindrical reflection member 37. In this way, by matching the outer shape of the surface-mounted LED 39 and the shape of the through hole 16 of the reflecting member, light does not leak outside through the gap between the light source 11 and the reflecting member.

  When light sources are provided at both ends of the light guide 2, the light emitted from the light source 11 provided at the other end of the light guide 2 and transmitted through the light guide 2 is more reflective than the light source substrate 12 or the like. The light can be incident on the light guide 2 more efficiently by folding back on the surface of the high surface mount LED 39.

  Furthermore, this embodiment also has the merit of an assembly surface. Since the light emitting portion 48 which is a region where light is emitted from the surface of the surface-mounted LED 39, bare chip LED, and organic EL is circular, according to the fourth embodiment, the cylindrical reflecting member 36 is used as the reflecting member of the present embodiment. May be installed. However, since the surface-mounted LED 39 has few irregularities, it is difficult for the light-emitting portion 48 to be inscribed in the through hole 16 of the cylindrical reflection member 36, and the cylindrical reflection member 36 cannot be stably installed. Therefore, by using the rectangular cylindrical reflection member 37 having the through hole 16 equal to the outer shape of the light source 11, the position is determined by aligning the end faces, and the reflection member 14 can be stably installed.

Embodiment 6 FIG.
The image reading apparatus according to the sixth embodiment of the present invention has the same function as that of a plurality of the reflecting members 14 described in the first to fifth embodiments, and is a reflection block 49 formed by making a hole in a metal block. Is used.
The image reading apparatus according to the sixth embodiment of the present invention is the same as those of the first to fifth embodiments except that the reflecting member is different. Therefore, only different points will be described below based on the third embodiment. In addition, the embodiment described below has the same effects as those of the first to fifth embodiments in addition to the effects caused by the configuration unique to the present embodiment.

  FIG. 25 is a schematic diagram showing a reflection block 49 in which three reflection members 14 are integrated. The metal block is provided with a through hole 16 having the same shape as the outer shape of the light source. In consideration of the reflectance of the regular reflection surface 15 formed in the through hole 16, the material of the metal block forming the reflection block 49 is preferably a metal having a high reflectance such as aluminum.

  FIG. 26 is a cross-sectional view of the illumination device using the reflection block 49 shown in FIG. 25 taken along the XY plane. In the light incident portions 13 provided at both ends of the light guide 2, three LEDs 46 with lenses 45 are disposed as the light source 11. The lens 45 portions of the three light sources are accommodated in the through holes 16 of the reflection block 49, and the reflection block 49 is in contact with the LED 46 portion of the light source.

  As described above, according to the sixth embodiment, by using the reflection block 49 in which a plurality of reflection members are integrated, the number of components can be reduced in an illumination device that requires a plurality of light sources such as an array light source. it can.

  In addition, as indicated by a broken arrow in FIG. 26, the light incident on the light incident portion 13 at one end of the light guide 2 and transmitted through the light incident portion 13 and leaked from the other end of the light guide 2 is converted into the light incident portion 13. It is possible to reflect the light at the end face of the reflection block 49 in contact with the light and return it to the light guide. Thereby, illumination efficiency can be increased compared with the case where the reflection member 14 is used.

  Furthermore, since the metal reflection block 49 is in close contact with the LED 46, the heat generated by the LED 46 can be absorbed by the reflection block 49 and transmitted to the frame outside the lighting device, so that a heat dissipation effect can also be obtained.

Embodiment 7 FIG.
The image reading apparatus according to the seventh embodiment uses a resin reflection block 19 formed of resin instead of the metal reflection block 49 described in the sixth embodiment.
The image reading apparatus according to the seventh embodiment of the present invention is the same as that of the sixth embodiment except that the reflecting member is different. Therefore, only differences will be described below based on the sixth embodiment. Further, the embodiment described below also has the same effect as that of the sixth embodiment in addition to the effect resulting from the configuration unique to the present embodiment.

  FIG. 27 is a schematic diagram showing the shape of the resin reflection block 19. The shape of the resin reflection block 19 is the same as that of the reflection block 49 shown in the sixth embodiment. However, since the resin reflection block 19 is made of resin, a mirror surface cannot be secured on the inner wall surface simply by providing the through hole 16. When the inner wall surface is a resin, even if a resin having a high reflectance is used, the hit light is scattered without being regularly reflected. Therefore, light is scattered on the inner wall of the through-hole 16 of the resin reflection block 19 and many reflections occur, and the inner wall absorbs light every time it is reflected, resulting in light loss. When the inner wall surface of the through hole 16 is made of resin, the incident efficiency to the light guide 2 is about 1/2 to 1/3 when the mirror surface of the inner wall surface of the through hole 16 can be secured.

  Therefore, it is necessary to form the regular reflection surface 15 on the inner wall surface of the through hole 16 of the resin reflection block 19 by metal vapor deposition or metal plating so that the reflection of light on the inner wall surface of the through hole 16 becomes regular reflection. is there. If the reflectance of 50% or more can be secured on the regular reflection surface 15, light guide incident efficiency comparable to that when the metal reflection block 49 is used can be secured.

  Resin is lighter and less expensive than metal, and can be molded with a single reflective block or other parts. For this reason, the use of the resin reflection block 19 facilitates assembly and reduces the mass production cost.

Embodiment 8 FIG.
In the image reading apparatus according to the eighth embodiment, the reflection block 49 or the resin reflection block 19 described in the sixth and seventh embodiments is divided into a plurality of parts. Below, a structure is demonstrated using the reflection block 49. FIG.
The image reading apparatus according to the eighth embodiment of the present invention is the same as the sixth and seventh embodiments except that the configuration of the reflecting member is different. Therefore, only differences will be described below based on the sixth embodiment. In addition, the embodiment described below also has the same effect as the sixth and seventh embodiments in addition to the effect resulting from the configuration unique to the present embodiment.

  FIG. 28 is a schematic diagram of the divided reflection block 40 in which the reflection block 49 described in the sixth embodiment is divided into two along the line GG shown in FIG. The division | segmentation reflection block 40 is divided | segmented so that the regular reflection surface 15 provided in the through-hole 16 may be exposed to the surface. FIG. 29 is a schematic diagram showing a state in which two divided reflection blocks 40 are overlapped so that the regular reflection surface 15 faces each other. In the eighth embodiment, the same function as that of the member before division is realized by using two divided members.

When the reflection block 49 is not divided into two, there are the following problems.
When the reflection block 49 is formed by making a hole in the metal block as in the sixth embodiment, it is necessary to polish the inner wall surface of the through-hole 16 in order to ensure a mirror surface of the regular reflection surface 15. Further, in the resin reflection block 19 according to the seventh embodiment, it is necessary to perform metal deposition in order to form the regular reflection surface 15 on the inner wall surface of the through hole 16.
However, in the configuration shown in Embodiments 6 and 7, when the lens of the light source 11 is as small as about 2 to 5 mm, the hole diameters of the through holes 16 of the reflection block 49 and the resin reflection block 19 are also reduced, and a mirror surface is secured. Therefore, there is a problem that it is difficult to polish. Another problem is that the yield of the metal molecules is deteriorated because the metal molecules evaporated during the metal deposition are not uniformly distributed on the inner wall surface of the through hole 16.

Therefore, referring to FIG. 28, by dividing the reflection block 49 and the resin reflection block 19 into two, the inner wall surface of the through hole 16 is exposed, and the regular reflection surface 15 is polished or metallized. It becomes easy to do. Therefore, the yield is improved in the manufacturing process of the reflection block 49 and the resin reflection block 19.

Embodiment 9 FIG.
In the image reading apparatus according to the ninth embodiment, an area for installing a filter 51 such as an IR cut filter is provided between the reflecting member described in the first to eighth embodiments and the light guide 2.
The image reading apparatus according to the ninth embodiment of the present invention is the same as those in the first to eighth embodiments except that the shape of the reflecting member and the presence or absence of the filter 51 are different. Therefore, only differences will be described below based on the sixth embodiment. In addition, the embodiment described below has the same effects as those of the first to eighth embodiments in addition to the effects caused by the configuration unique to the present embodiment.

  When acquiring a color image, a method is generally used in which a band pass filter is installed in front of the sensor 4 and each wavelength component RGB separated by the band pass filter is detected by the sensor 4. However, when the bandpass filter installed in front of the sensor 4 transmits wavelengths other than the target wavelength such as infrared, or the light source 11 emits ultraviolet light or infrared light other than visible light, the sensor 4 May detect light other than the target wavelength. In such a case, it is necessary to install a filter 51 that cuts light other than visible light between the light source 11 and the light guide 2.

Therefore, an area for installing a filter 51 such as an IR cut filter is provided between the light guide 2 and the reflection block 49.
FIG. 30 is a plan view of the lighting device shown in FIG. 26, in which a part of the end of the reflection block 49 in contact with the light incident portion 13 of the light guide 2 is shaved, It is a schematic diagram showing a state where an area for storing the filter 51 is provided and the filter 51 is placed in the area. The filter 51 is fixed by being sandwiched between the light incident part 13 of the light guide 2 and the end face of the reflection block 49.

  As described above, in an image reading apparatus that requires the filter 51, by providing the reflecting member 14 or the reflecting block 49 with a groove on which the filter 51 can be installed, the incident efficiency to the light guide 2 is increased, and the component Various filters 51 can be installed without increasing the number of points.

Embodiment 10 FIG.
The image reading apparatus according to the tenth embodiment uses an integral member 52 in which the reflecting member according to the first to ninth embodiments is integrated with the holder 10.
The image reading apparatus according to the tenth embodiment of the present invention is the same as those of the first to ninth embodiments except that the shapes of the reflecting member and the holder are different. Therefore, only differences will be described below based on the sixth embodiment. In addition, the embodiment described below has the same effects as those of the first to ninth embodiments in addition to the effects resulting from the configuration unique to the present embodiment.

  FIG. 31 is a schematic diagram showing an example of the shape of the integral member 52 in which the reflection block 49 shown in FIG. 26 is integrated with the holder 10. 31B is a cross-sectional view taken along line GG in FIG. 31A, and FIG. 31C is a cross-sectional view taken along line HH in FIG.

  Referring to FIGS. 31A to 31C, a groove 57 having a shape in which the light guide 2 shown in FIG. 2 is accommodated is cut in the integrated member 52 from the end surface of the integrated member 52 to the middle. Further, the bottom surface of the groove 57 is provided with three holes (through holes) 54 penetrating to the opposite end surface, and the regular reflection surface 15 is formed on the inner wall surface of the through hole 54.

  The end portion of the light guide 2 is inserted into the groove 57 of the integrated member 52, and the light source substrate 12 on which the light source 11 is mounted is installed on the end surface having the opening of the through hole 54. The light guide 2 is fixed at a predetermined position by installing the integral member 52 inside the housing 9.

  As described above, by using the integrated member 52 in which the reflection block 49 and the holder 10 are integrated, the number of members of the lighting device can be reduced.

  Further, the integrated members 52 provided on the two light guides 2 arranged with the reading optical system 5 interposed therebetween are connected to one by referring to FIG. The number of members can be reduced.

Embodiment 11 FIG.
The image reading apparatus according to the eleventh embodiment uses a joining member 23 obtained by joining the reflecting member 14 described in the first to fifth embodiments to a plate material 58 having a hole.
The image reading apparatus according to the eleventh embodiment of the present invention is the same as the first to fifth embodiments except that the reflecting member is different. Therefore, only different points will be described below based on the third embodiment. In addition, the embodiment described below has the same effects as those of the first to fifth embodiments in addition to the effects caused by the configuration unique to the present embodiment.

  FIG. 33 is a schematic diagram showing the shape of the joining member 23. The joining member 23 includes the plate member 58 and the reflecting member 14 described in the third embodiment.

  The plate member 58 has a hole 22 having the same shape as the hole shape of the through hole 16 of the reflecting member 14 described in the third embodiment with reference to FIG. Further, it is desirable that the plate member 58 is made of a metal, a resin subjected to metal vapor deposition, glass, or the like in order to ensure reflectivity.

  The reflection member 14 is joined to the plate material 58 so that the through hole 16 of the reflection member 14 and the hole 22 provided in the plate material 58 overlap when viewed from the optical axis direction. 35 is a cross-sectional view taken along the line II of FIG. 36 is a cross-sectional view taken along line JJ of FIG. The light incident portion 13 of the light guide 2 abuts on the plate material 58, and the light source 11 abuts on the reflection member 14 joined to the joining member 23.

  With the configuration described above, the light that enters from the light incident portion 13 provided at one end of the light guide 2 and passes through the inside and then leaks from the other end of the light guide 2 is reflected by the plate material 58. Thus, it can be returned into the light guide 2. Thereby, the improvement of the illumination efficiency same as when the reflective block 49 is installed between the light guide 2 and the light source 11 as in the sixth embodiment can be expected.

  Further, if the reflecting member 14 has a shape as in the eleventh embodiment, the amount of material necessary for production can be significantly reduced as compared with the reflecting block 49 shown in the sixth embodiment. Therefore, the cost can be reduced and the weight can be reduced.

Embodiment 12 FIG.
In the image reading apparatus according to the twelfth embodiment, the reflection member 14 and the regular reflection surface 15 of the reflection block 49 described in the first to eleventh embodiments are inclined.
The image reading apparatus according to the twelfth embodiment of the present invention is the same as the first to eleventh embodiments except that the shape of the reflecting member is different. Therefore, only the differences will be described below based on the first embodiment. In addition, the embodiment described below also has the same effects as those of the first to eleventh embodiments in addition to the effects caused by the configuration unique to the present embodiment.

  Referring to FIG. 37, the reflecting member 59 provided between the light source 11 and the light incident portion 13 of the light guide 2 is a cylindrical body (pipe shape) having a through hole 64, and is formed in the first opening 17. The light source 11 is in contact, and the light incident part 13 of the light guide 2 is in contact with the second opening 18. A regular reflection surface 15 is formed on the inner wall surface of the through hole 64.

The shape of the through hole 64 of the reflecting member 59 will be described in detail with reference to FIG.
The diameter of the opening of the first opening 17 of the reflecting member 59 is φ1, the diameter of the opening of the second opening 18 is φ2, the diameter of the light source 11 is λ, and the diameter of the light emitting portion 33 of the light source 11 is φ. Moreover, the thickness of the depth direction in the position which fixes the holder 10 among the light-incidence parts 13 of the light guide 2 is set to (tau).
At this time, the diameter φ1 of the opening of the first opening 17 is set to be not less than the diameter ψ of the light emitting part 33 of the light source 11 and not more than the diameter λ of the light source 11 (equation (5)). Further, the diameter φ2 of the opening of the second opening 18 is set to be equal to or less than the thickness τ in the depth direction of the light incident part 13 of the light guide 2 (Equation (6)). The opening φ1 on the light guide 2 side and the opening φ2 on the light source 11 side have different sizes (formula (7)).
ψ ≦ φ1 ≦ λ (5)

φ2 ≦ τ (6)

φ1 ≠ φ2 Equation (7)

  As described above, the regular reflection surface 15 is inclined by changing the sizes of the openings at both ends of the through hole 64 provided in the reflection member 59.

Advantages obtained by inclining the regular reflection surface 15 will be described below.
First, referring to FIG. 37, the opening of second opening 18 is formed to be larger than the opening of first opening 17. As a result, part of the light transmitted through the light guide 2 is folded back along the optical path indicated by the broken-line arrow in FIG. 37 and enters the light guide 2 again. As a result, since the transmitted light from the light guide 2 can be efficiently returned to the light guide 2, the illumination efficiency can be improved.

  Referring to FIG. 38, the opening of the second opening 18 is formed to be smaller than the opening of the first opening 17, and a white LED is used as the light source 11. In general, a white LED is provided with a phosphor 61 in front of an LED chip 60 that emits blue light. The blue light that hits the phosphor 61 is converted into red and green light, and white light is emitted as the total. Therefore, the color of light emitted from the light source 11 is determined by the efficiency with which the phosphor 61 converts blue light into red and green. Therefore, the color of the light source 11 can be adjusted by returning the light emitted from the light source 11 along the optical path indicated by the solid line arrow in FIG. 38 to the phosphor 61 again and converting it from blue to red or green light again. become.

  Moreover, it becomes easy to perform metal vapor deposition of the regular reflection surface 15 by providing an inclination. When performing metal vapor deposition, it is necessary to secure a projected area 25 of a surface on which metal vapor deposition is desired with respect to the vapor deposition direction 24 in which molecules of the vapor deposited metal fly. Referring to FIG. 39, when the regular reflection surface 15 is not inclined, it is necessary to perform metal deposition in two steps from different directions. However, referring to FIG. 40, by providing the regular reflection surface 15 with an inclination, the projected area 25 of all the regular reflection surfaces 15 can be secured at the same time, so that metal deposition can be performed at a time. Thereby, the manufacturing cost and time can be reduced and the yield can be improved.

Embodiment 13 FIG.
In the image reading apparatus according to the thirteenth embodiment, the regular reflection surface provided for each light source 11 is connected to one, and a plurality of light sources 11 are installed in a space surrounded by one regular reflection surface 63. is there.
The image reading apparatus according to the thirteenth embodiment of the present invention is the same as the first to twelfth embodiments except that the shape of the reflecting member is different. Therefore, only differences will be described below based on the sixth embodiment. In addition, the embodiment described below has the same effects as those of the first to twelfth embodiments in addition to the effects resulting from the configuration unique to the present embodiment.

  FIG. 41 is a schematic diagram showing the shape of the reflecting member 62 used in the present embodiment. The reflecting member 62 is formed by removing the walls between the through holes 16 in the reflecting block 49 shown in FIG.

Since the through hole 16 of the reflection block 49 is formed in accordance with the size of the light source 11, depending on the size of the light source 11 and the light guide 2 to be used, the diameter of the through hole 16 and the distance between the adjacent through holes 16 are different. There are cases where the wall becomes several mm and machining and molding become difficult.
Therefore, referring to FIG. 41, the wall between the plurality of through holes provided in the reflecting member is eliminated, and the reflecting surface 63 is connected to one, so that the reflecting member can be easily manufactured.

  DESCRIPTION OF SYMBOLS 1 Original, 2 Light guide, 3 Transparent body, 4 Sensor (sensor IC), 5 Reading optical system (rod lens array), 6 Sensor board, 7 Signal processing IC (ASIC), 8 External connector, 9 Case, 10 Holder, 11 Light source, 12 Light source substrate, 13 Light incident part, 14 Reflecting member, 15 Regular reflection surface, 16 Through hole, 17 First opening part, 18 Second opening part, 19 Resin reflection block, 20 Light guide path, 21 Condensing lens, 22 holes, 23 bonding member, 24 deposition direction, 25 projection area, 30 image reading area, 31 light emitting part, 32 light scattering area, 33 light emitting part, 34 reflective light guide, 35 refractive light guide Body, 36 cylindrical reflection member, 37 square tube reflection member, 38 shell-type light source, 39 surface mount LED, 40 split reflection block, 41 power connector, 42 reflected light, 43 Projection surface, 44 Refraction surface, 45 Condensing part, 46 LED, 47 Cannonball part, 48 Light emitting part, 49 Reflection block, 50 Resin, 51 Filter, 52 Integrated member, 53 block, 54 Through hole, 55 arrow, 56 arrow , 57 groove, 58 plate material, 59 reflection member, 60 LED chip, 61 phosphor, 62 reflection member, 63 regular reflection surface, 64 through hole.

Claims (5)

An illumination device for irradiating reading light to a reading area to be read,
A light source having a light emitting portion that is a region from which light is emitted;
A reflection member that has a through hole formed with a regular reflection surface that totally reflects light on its inner wall, and is installed in a state in which the optical axis of the light emitted from the light emitting portion passes through the inside of the through hole;
A light guide having a light incident part and a light emitting part, and light that has passed through the through-hole and entered from the light incident part propagates through the inside and is emitted from the light emitting part toward the reading region. Prepared,
The light source is in contact with one opening of the through hole, and the light incident portion is in contact with the other opening,
When the respective overlaps of the light source, the one opening of the through hole, the other opening of the through hole, and the light incident portion are viewed from the direction of the optical axis, the one opening of the through hole is the opening of the light source. The illumination is characterized in that the shape of one opening of the through hole coincides with the outer shape of the light emitting portion , and the other opening of the through hole is in the region of the light incident portion. apparatus.   The lighting device according to claim 1, wherein the reflection member includes a groove in which a filter for cutting light other than a predetermined wavelength is installed. A plurality of light sources are arranged in the light incident part,
The lighting device according to the reflecting member to claim 1 or claim 2, characterized in that arranged in each of the light source. By opening a hole having the same shape as the light emission portion as viewed from the direction of the optical axis member of the block-shaped, according to any one of claims 1 to 3, characterized in that the formation of the reflecting member Lighting device. Image reading apparatus characterized by irradiating the reading light to the reading area of the reading target by using the illumination device according to any one of claims 1 4.

Images