JP2008129247A - Light emitting device, image reader, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low cost light-emitting device, an image reader and an image forming apparatus, which uniform an irradiation distribution on an irradiation area with a simple configuration, and satisfactorily read an irradiated body. <P>SOLUTION: The light emitting device 50 includes: a light emitting diode 43 that emits light to a fixed irradiation area E of a contact glass 15, thereby illuminating a document P present on the contact glass 15 through the contact glass 15; and a circuit board 51 holding the light emitting diode 43 in a holding position. In the light emitting device 50, the circuit board 51 is disposed between the light emitting diode 43 and contact glass 15. In addition, the light emitting diode 43 is disposed in the holding position separated from the irradiation area E side end 51a of the circuit board 51 in the direction opposite to the irradiation area E. Thus, a light shield section 51b is formed on the circuit board 51 so as to extend toward the irradiation area E from the holding position of the light emitting diode 43. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light irradiation apparatus, an image reading apparatus, and an image forming apparatus, and, for example, an image reading apparatus such as a scanner apparatus including a light emitting element that irradiates light to an irradiated object in order to read the irradiated object such as a document, and the like. The present invention relates to an image forming apparatus such as a facsimile machine, a copying machine, and a multi-function machine equipped with the image reading device.

  In general, in an image reading apparatus such as a scanner provided in a facsimile machine, a copier, a multifunction machine, etc., a CCD image is obtained by irradiating light from a light source onto a document and folding reflected light from the document with a plurality of mirrors. The light is incident on an image sensor such as a sensor.

  FIG. 13 is a configuration diagram of a conventional image reading apparatus. In FIG. 13, the light emitted from the cylindrical xenon lamp 111 to the document placed on the contact glass 117 is reflected by the first mirror 112a and then folded in the order of the second mirror 112b and the third mirror 112c. It is like that.

  The reflected light reflected by the third mirror 112 c is imaged on the image sensor 114 such as a CCD image sensor by the imaging lens 113 and is photoelectrically converted by the image sensor 114.

  The xenon lamp 111 and the first mirror 112a are mounted on the first carriage 115, and the second mirror 112b and the third mirror 112c are mounted on the second carriage 116. When reading, the first carriage 115 and the second carriage 116 travel in the sub-scanning direction, and main scanning of the document is performed by the xenon lamp 111, whereby the entire document surface is read.

  Conventionally, as shown in FIG. 14, the reflector 118 is disposed opposite to the xenon lamp 111 in the sub-scanning direction of the document so that the irradiation light from the xenon lamp 111 is reflected by the reflector 118 to the document. I have something to do. In this way, it is possible to optimize the illuminance distribution of the irradiation area on the contact glass 117 from the xenon lamp 111, and to eliminate the shadow caused by the step of the document when the cut and pasted document is read.

  In such an image reading apparatus, there is a demand for the rise speed of the light source, energy saving, long life, etc. Recently, a light source using a light emitting element such as a light emitting diode instead of the xenon lamp 111 is used. There is a tendency to adopt.

  15 and 16 are diagrams showing an image reading apparatus employing a light emitting diode. 15 and 16, a bracket 121 having a V-shaped cross section is attached to the first carriage 115, and a light emitting diode 122 and a circuit board 123 that drives the light emitting diode 122 are attached to the bracket 121.

Incidentally, in the image reading apparatus employing the reduction optical system shown in FIG. 14, since the distance from the document surface to the image sensor 114 is long, the attenuation of the irradiation light from the light source increases during that time. It is necessary to increase the illuminance at 122.
For this reason, a plurality of light emitting diodes 122 are installed in the main operation direction of the original so as to increase the illuminance on the original.

  In addition, when the light emitting diodes 122 are arranged in an array, the light emitting diodes 122 are disposed so as to be opposed to the document surface by the bracket 121 in order to obtain a good illuminance distribution in the sub-scanning direction on the document surface. It is preferable that the illuminance distribution in the sub-scanning direction on the original surface at this time is such that light is applied only to the irradiation area E of the original surface indicated by diagonal lines, that is, the actual reading area of the original, as shown in FIG. Is desirable.

  However, even in the case where the light emitting diode 122 is inclined and the irradiation light from the light emitting diode 122 is reflected on the document surface by the reflector 118, the illuminance distribution in the sub-scanning direction on the document surface is shown in FIG. Thus, light will be irradiated also to areas other than the irradiation area E.

  In this case, for example, when an image having a small black solid portion sandwiched between white is read, the light reflected by the white original in the irradiation region E enters the image sensor 114 and is output from the black solid portion. Since the value increases, the black solid cannot be reproduced faithfully.

In order to solve such a problem, a long light guide member is provided on the irradiation surface of the light emitting diode, and the light emitted from the light emitting diode is guided by this light guide member into the irradiation region, thereby reducing the illuminance distribution. There is an illuminating device that is made uniform in an irradiation region (see, for example, Patent Document 1).
JP 2004-361425 A

  However, in such a conventional lighting device, since the long light guide member is attached to the irradiation surface of the light emitting diode, the number of parts increases and the manufacturing cost of the lighting device increases. There was a problem.

  The present invention has been made in order to solve the conventional problems, and it is possible to make the irradiation distribution on the irradiation region uniform with a simple configuration and to perform low-cost light irradiation that can read the irradiated object satisfactorily. An object is to provide an apparatus, an image reading apparatus, and an image forming apparatus.

  The light irradiation apparatus according to the present invention includes a light emitting element that irradiates a certain irradiation region of a transparent member with light and irradiates an irradiated object existing on the transparent member through the transparent member, and the light emitting element at a holding position. In a light irradiation apparatus having a holding member to hold, the holding member is installed between the light emitting element and the transparent member, and the light emitting element is placed in the opposite direction to the irradiation area from the irradiation area side end of the holding member. By being installed at the holding positions that are separated from each other, the holding member is formed of a light shielding portion that extends from the holding position of the light emitting element toward the irradiation region.

  With this configuration, the holding member is installed between the light emitting element and the transparent member, and the light emitting element is installed at a holding position that is separated from the irradiation region side end of the holding member in the direction opposite to the irradiation region, thereby emitting light to the holding member. Since the light shielding part extending from the holding position of the element toward the irradiation area is formed, the direct light irradiated outside the irradiation area is shielded by the light shielding part, and the irradiation light from the light emitting element is guided to the irradiation area. be able to. For this reason, it is possible to read the irradiated object satisfactorily by making the irradiation distribution on the irradiation region uniform.

  In addition, for example, the light shielding part can be formed with a simple structure by installing the light emitting element on the lower surface of the holding member and installing the light emitting element at a position separated from the irradiation region side end. An increase in the manufacturing cost of the apparatus can be prevented.

  In addition, the holding member of the light irradiation device of the present invention is composed of a circuit board that drives the light emitting element.

  With this configuration, the light shielding element can be formed with a simple structure by installing the light emitting element on the lower surface of the circuit board and disposing the light emitting element at a position away from the irradiation region side end. An increase in the manufacturing cost of the apparatus can be prevented.

  In addition, the light irradiation apparatus of the present invention includes a circuit board that holds the light emitting element and drives the light emitting element, and the holding member holds the circuit board in the holding position and can be attached to the image reading apparatus. It is comprised from what consists of a mounting member.

  With this configuration, the light emitting element and the circuit board are located at positions separated from the irradiation region side end of the mounting member with the light emitting element on the lower surface with respect to the mounting member for holding the light emitting element and the circuit board in the image reading apparatus. Since the light shielding portion can be formed with a simple structure, it is possible to prevent an increase in the manufacturing cost of the light irradiation device.

  In addition, the light emitting element of the light irradiation device of the present invention is configured to be installed at a first holding position in the vicinity of the irradiation region side end of the circuit board.

  With this configuration, by installing the light emitting element at the first holding position in the vicinity of the irradiation region side end portion of the circuit board, the length of the light shielding portion can be shortened, and the light shielding amount can be reduced. . For this reason, it is possible to adjust the width of the irradiation region in the sub-scanning direction widely while shielding the direct light irradiated outside the irradiation region by the light shielding unit.

  Further, the light emitting element of the light irradiation apparatus of the present invention is configured to be installed at a second holding position that is separated from the first holding position near the irradiation region side end of the circuit board in a direction opposite to the irradiation region. ing.

  With this configuration, the length of the light shielding portion is increased by installing the light emitting element at the second holding position that is separated from the first holding position near the irradiation region side end of the circuit board in the direction opposite to the irradiation region. And the amount of light shielding can be increased. For this reason, the width of the irradiation region in the sub-scanning direction can be narrowly adjusted while shielding the direct light irradiated outside the irradiation region by the light shielding unit.

  The light emitting element of the light irradiation apparatus of the present invention includes a first holding position in the vicinity of the irradiation region side end of the circuit board, and a second holding separated from the irradiation region side end in the opposite direction to the irradiation region. It is comprised from what is installed in the 3rd holding position between positions.

  With this configuration, the light-emitting element is held in a third position between the first holding position in the vicinity of the irradiation region side end of the circuit board and the second holding position separated from the irradiation region side end in the opposite direction to the irradiation region. By installing in the position, the length of the light shielding part can be set to the length between the light emitting element installed in the first holding position or the second holding position. For this reason, the direct light irradiated to other than the irradiation region is shielded by the light shielding unit, and the width of the irradiation region in the sub-scanning direction is set between the irradiation regions when the light emitting element is in the first holding position or the second holding position. The width can be adjusted.

  Moreover, the irradiation area side edge part of the circuit board of the light irradiation apparatus of this invention is comprised from what is installed in the 1st holding position of the irradiation area side edge part vicinity of the said mounting member.

  With this configuration, the length of the light shielding portion can be shortened by installing the irradiation region side end of the circuit board at the first holding position in the vicinity of the irradiation region side end of the mounting member, and the amount of light shielding Can be reduced. For this reason, it is possible to adjust the width of the irradiation region in the sub-scanning direction widely while shielding the direct light irradiated outside the irradiation region by the light shielding unit.

  In addition, the irradiation region side end of the circuit board of the light irradiation apparatus of the present invention is installed at a second holding position that is separated from the first holding position near the irradiation region side end of the mounting member in a direction opposite to the irradiation region. It is composed of what will be done.

  With this configuration, the end of the circuit board on the irradiation region side is installed at a second holding position that is spaced apart from the first holding position in the vicinity of the irradiation region side end of the mounting member in the direction opposite to the irradiation region, thereby shielding light. The length of the portion can be increased, and the amount of light shielding can be increased. For this reason, the width of the irradiation region in the sub-scanning direction can be narrowly adjusted while shielding the direct light irradiated outside the irradiation region by the light shielding unit.

  Further, the irradiation region side end of the circuit board of the light irradiation apparatus of the present invention includes a first holding position near the irradiation region side end of the mounting member and an irradiation region from the vicinity of the irradiation region side end of the mounting member. It is comprised from what is installed in the 3rd holding position between the 2nd holding positions spaced apart in the opposite direction.

  With this configuration, the irradiation region side end of the circuit board has a first holding position in the vicinity of the irradiation region side end of the mounting member, and a second holding position that is separated from the irradiation region side end in the opposite direction to the irradiation region. When the light-emitting element is installed at the first holding position or the second holding position, the length of the light shielding portion can be set to the length between them. For this reason, the direct light irradiated to other than the irradiation region is shielded by the light shielding unit, and the width of the irradiation region in the sub-scanning direction is set between the irradiation regions when the light emitting element is in the first holding position or the second holding position. The width can be adjusted.

In addition, the holding surface of the holding member that holds the light emitting element of the light irradiation device of the present invention is configured to extend in a direction substantially perpendicular to the irradiation surface of the light emitting element.
With this configuration, for example, the light shielding portion can be positioned above the irradiation surface of the light emitting element, so that a part of the light emitted from the light emitting element is reliably shielded by the light shielding portion to the irradiation region. Light can be guided, and the irradiation distribution on the irradiation region can be made uniform.

  Further, the light emitting element of the light irradiation apparatus of the present invention is located outward from one end portion in the sub-scanning direction with respect to the irradiation region, and the irradiation region side end portion of the holding member is a direction substantially orthogonal to the holding surface. Are arranged on a line connecting the end portion in the extending direction of the irradiation surface of the light emitting element and the one end portion in the sub-scanning direction of the irradiation region.

  With this configuration, the irradiation region side end portion of the holding member is connected to the extending direction end portion of the light emitting element extending in the direction orthogonal to the holding surface and the one end portion of the irradiation region in the sub-scanning direction. Since it was made to be located on the line, for example, the light shielding part can be located above the irradiation surface of the light emitting element. For this reason, a part of the light emitted from the light emitting element can be reliably shielded by the light shielding part, and the light can be guided to the irradiation region, and the irradiation distribution on the irradiation region can be made uniform.

Moreover, the light irradiation apparatus of this invention is comprised from what made the said light-shielding part surface at the side of the holding surface of the said light emitting element black.
With this configuration, since the surface of the light shielding portion on the holding surface side of the light emitting element is made black, it is possible to easily absorb the irradiation light by the light shielding portion and to reduce the irradiation light passing through the light shielding portion. For this reason, it is possible to prevent unintended light from being irradiated outside the irradiation region, and to uniformly read the irradiated object by making the irradiation distribution on the irradiation region uniform.

In the light irradiation apparatus of the present invention, the holding member is composed of a light shielding member.
With this configuration, since the holding member is formed of a light shielding member, unnecessary light can be reliably blocked by the light shielding portion, and unintended light can be prevented from being irradiated outside the irradiation region. . For this reason, the irradiation distribution on the irradiation region can be made uniform and the irradiated object can be read well.

Moreover, the light emitting element of the light irradiation apparatus of the present invention is constituted by a plurality of light emitting elements provided along the main scanning direction of the irradiated object.
With this configuration, the amount of irradiation light can be increased, and when used in an image reading apparatus employing a reduction optical system, the irradiation area is irradiated even when the distance from the document surface to the image sensor is long. The light can reach the image sensor, and the reading accuracy of the irradiated object can be prevented from being lowered.

The image reading apparatus according to the present invention includes the above-described light irradiation device.
With this configuration, the holding member is installed between the light emitting element and the transparent member, and the light emitting element is installed at a holding position that is separated from the irradiation region side end of the holding member in the direction opposite to the irradiation region, thereby emitting light to the holding member. Since the light shielding part extending from the holding position of the element toward the irradiation area is formed, the direct light irradiated outside the irradiation area is shielded by the light shielding part, and the irradiation light from the light emitting element is guided to the irradiation area. be able to. For this reason, it is possible to read the irradiated object satisfactorily by making the irradiation distribution on the irradiation region uniform.

  In addition, for example, the light shielding part can be formed with a simple structure by installing the light emitting element on the lower surface of the holding member and installing the light emitting element at a position separated from the irradiation region side end. An increase in the manufacturing cost of the apparatus can be prevented, and as a result, an increase in the manufacturing cost of the image reading apparatus can be prevented.

An image forming apparatus according to the present invention includes an image forming unit that forms an image on a recording medium and includes the above-described image reading apparatus.
With this configuration, the holding member is installed between the light emitting element and the transparent member, and the light emitting element is installed at a holding position that is separated from the irradiation region side end of the holding member in the direction opposite to the irradiation region, thereby emitting light to the holding member. Since the light shielding part extending from the holding position of the element toward the irradiation area is formed, the direct light irradiated outside the irradiation area is shielded by the light shielding part, and the irradiation light from the light emitting element is guided to the irradiation area. be able to. For this reason, it is possible to read the irradiated object satisfactorily by making the irradiation distribution on the irradiation region uniform.

  In addition, for example, the light shielding part can be formed with a simple structure by installing the light emitting element on the lower surface of the holding member and installing the light emitting element at a position separated from the irradiation region side end. An increase in the manufacturing cost of the apparatus can be prevented, and as a result, an increase in the manufacturing cost of the image forming apparatus can be prevented.

  The present invention provides a low-cost light irradiation apparatus, an image reading apparatus, and an image forming apparatus that can make the irradiation distribution on the irradiation region uniform with a simple configuration and can read the irradiated object satisfactorily. Can do.

Hereinafter, embodiments of a light irradiation device, an image reading device, and an image forming device according to the present invention will be described with reference to the drawings.
1 to 8 are diagrams showing a first embodiment of a light irradiation apparatus, an image reading apparatus, and an image forming apparatus according to the present invention, and a copying machine provided with a scanner device using the image forming apparatus as an image reading apparatus. The example applied to is shown.
The image forming apparatus is not limited to a copying machine, but can be applied to an image forming apparatus such as a facsimile machine or a multifunction machine having a copying function and a facsimile function.

  First, the configuration will be described. In FIG. 1, the copying machine 10 includes an automatic document feeder 11, a paper feeding unit 12, an image reading unit (image reading device) 13, and an image forming unit (image forming unit) 14.

  The automatic document feeder 11 conveys a document placed on a document tray 16 onto a contact glass 15 by a separation feeding unit 17 including various rollers such as a feeding roller and a separation roller, and conveys a document that has been read. After being carried out from the contact glass 15 as a transparent member by the belt 18, the paper is discharged onto a paper discharge tray 20 by a paper discharge means 19 including various paper discharge rollers.

  When reading both sides of the document, the document is returned onto the contact glass 15 by the branching mechanism provided on the paper discharge means 19 and the conveyor belt 18 to read the unread surface.

  The paper feed unit 12 is made up of paper feed cassettes 21a and 21b that store recording papers as recording media of different sizes, and paper feed that includes various rollers that transport the recording papers stored in the paper feed cassettes 21a and 21b to the transfer position. And means 22.

  As will be described in detail later, the image reading unit 13 drives the first carriage 35 and the second carriage 36 in the left-right direction (sub-scanning direction) in FIG. The surface is read, and the reading light is reflected by a mirror, and then taken into an image reading sensor such as a CCD by the lens unit 37.

  The image forming unit 14 includes an exposure device 23 that forms a write signal based on a read signal taken into the lens unit, a plurality of photosensitive drums 24 on which a write signal generated by the exposure device 23 is formed, A developing device 25 that fills each photosensitive drum 24 with toners of different colors, such as cyan, magenta, yellow, and black, and visualizes the write signal on each photosensitive drum 24; The formed visible image is superimposed and transferred to form a color image, and the color image is transferred to the recording paper fed from the paper feeding unit 12 and fixed to the recording paper. And a fixing device 27 for fixing the color image on the recording paper.

  2 and 3 are diagrams showing the configuration of the image reading unit 13. FIG. 2 is a side view showing the positional relationship between the components of the image reading unit 13. FIG. 3 is a schematic diagram for explaining the relationship between the driving wire 33 for driving the second carriage 36 and each pulley. FIG. 3A is a side view, and FIG. 3B is a diagram showing the connection state of the drive wires 33 as viewed from above.

  2 and 3, the image reading device 13 includes a main body frame 31, a drive shaft 32, a drive wire 33, a wire drive pulley 34, a first carriage 35, a second carriage 36, a lens unit 37, a tension spring 39, and a carriage pulley 40. , Idler pulleys 41 and 42 and an image sensor 57 are provided.

  A first rail and a second rail (not shown) are provided inside the main body frame 31, and a first carriage 35 as a traveling body is slidably attached to the first rail, and the second rail is attached to the first rail. The second carriage 36 is slidably attached.

  The drive shaft 32 is connected to a motor (not shown), and wire drive pulleys 34 are attached to both ends of the drive shaft. A drive wire 33 is wound around the wire drive pulley 34, and the drive wire 33 extends in the left-right direction in FIG. 3, which is a predetermined direction.

  Two drive wires 33 are used for driving the first carriage 35 and for driving the second carriage 36. FIG. 3 shows the drive wire 33 for driving the second carriage 36.

The drive wire 33 and the idler pulleys 41 and 42 are provided one by one on the front and rear sides of the main body frame 31, but both have the same configuration and function, so the drive wire 33 and the idler pulleys 41 and 42 on one side will be described. do. That is, in the present embodiment, two wires 33 and four idler pulleys 41 and 42 are provided at the four corners of the main body frame 31.
The second carriage 36 is provided with a carriage pulley 40, and the drive wire 33 passes through the carriage pulley 40 and idler pulleys 41 and 42.

  As shown in FIGS. 4 and 5, the first carriage 35 includes a flat base plate 35a and a pair of side plates 35b suspended from the base plate 35a. A first mirror 44a is attached between the side plates 35b. It has been. In FIG. 4, a pair of side plates 35b are provided apart from each other in the paper surface direction, but only one side plate 35b is shown in FIG.

  A flat circuit board 51 as a holding member is attached to the base plate 35a via a bracket 52 as a mounting member, and a light emitting diode 43 as a light emitting element is attached to the circuit board 51 in the main scanning direction of the document. A plurality are attached along. In the present embodiment, the light emitting diode 43, the circuit board 51, the bracket 52, the reflector 53, and the first carriage 35 constitute the light irradiation device 50.

  The light emitting diode 43 is driven by the circuit board 51 so as to emit light from the irradiation surface 43 a toward the contact glass 15. The circuit board 51 is fixed to a bracket 52 by screws or adhesion, and the bracket 52 is formed in a substantially V-shaped cross section and is made of metal such as sheet metal or aluminum.

  The first carriage 35 is provided with a reflector 53 so as to face the light irradiation device 50 in the sub-scanning direction, and the upper part of the reflector 53 receives the light emitted from the light emitting diode 43 on the contact glass 15. A bent portion 53a is formed that is bent to the left in the sub traveling direction, that is, to the traveling direction return side of the first carriage 35. The base plate 35b, the side plate 35b, and the reflector 53 are integrally formed of a mold resin.

  The reflector 53 is configured such that the light emitted from the light emitting diode 43 is reflected on the original surface by the bent portion 53a, and when the cut and pasted original is read, the shadow caused by the step of the original can be eliminated.

  In this way, the irradiation light from the light emitting diode 43 is irradiated to the irradiation region E of the contact glass 15 by the irradiation light from the light emitting diode 43 and the reflection light from the reflector 53. In the present embodiment, a certain range in which light is irradiated onto the contact glass 15 by the light emitting diode 43 is the irradiation region E. The irradiation area E is an area extending in the sub-scanning direction of the document.

  Therefore, an image of the original P as an irradiated body existing on the contact glass 15 in the irradiation area E is read.

The holding surface of the circuit board 51 with respect to the light emitting diode 43 extends in a direction substantially perpendicular to the irradiation surface 43 a of the light emitting diode 43.
The holding surface of the circuit board 51 is a surface on the side where the light emitting diodes 43 are attached, and is the entire back surface of the circuit board 51 in FIG. The holding position of the circuit board 51 is a position where the light emitting diode 43 is fixed to the circuit board 51 on the holding surface of the circuit board 51.

The circuit board 51 is disposed between the light emitting diode 43 and the contact glass 15, and the light emitting diode 43 is disposed below the circuit board 51.
The light emitting diode 43 is installed at a holding position that is separated from the end portion 51 a on the irradiation region E side of the circuit board 51 in the opposite direction to the irradiation region E, and the circuit board 51 has a holding surface that holds the light emitting diode 43. A light shielding part 51b (indicated by oblique lines) extending from the upper holding position toward the irradiation region E is formed.

  Further, the light emitting diode 43 is located at one end in the sub-scanning direction with respect to the irradiation region E, that is, outward from the right end of the irradiation region E in FIG. 4, and the end 51a of the circuit board 51 is the circuit board. The extending direction end of the irradiation surface 43a of the light emitting diode 43 extending in a direction substantially orthogonal to the holding surface 51, that is, the lower end portion of the irradiation surface 43a and the one end portion in the sub-scanning direction of the irradiation region E in FIG. It is located on the connected line b.

  Therefore, the light is leaked by the light shielding portion 51b to the right in the sub travel direction with respect to the irradiation area E, that is, in the direction in which the first carriage 35 travels to the sub scan side of the document P, as indicated by a in FIG. Can be prevented, and light can be irradiated within the irradiation region E.

  The circuit board 51 is made of a light shielding member that has a high light density and hardly transmits light, such as a polyester film containing carbon or a PET material, and the light shielding portion 51b reliably shields the light. Can be done.

  On the other hand, an opening 35c is formed in the base plate 35b. Light emitted from the light emitting diode 43 to the original P and reflected from the original P is incident on the first mirror 44a through the opening 35c.

  Further, the first carriage 35 is disposed between the wire drive pulley 34 and the second carriage 36, and when the first carriage 35 is pulled by the drive wire 33 and travels at a predetermined speed V, the light irradiation device 50 causes the contact glass 15. The document placed on is sub-scanned.

  When the document is irradiated from the light emitting diode 43, the reflected light of the document is folded back toward the second carriage 36 by the first mirror 44a, and the reflected light is mounted on the second carriage 36. After further folding back by the second mirror 44b and the third mirror 44c, the light enters the lens unit 37.

  The reflected light is condensed and imaged on an imaging element 57 such as a CCD placed on the focal plane by an imaging lens included in the lens unit 37. As a result, the image sensor 57 performs main scanning on the line on the document along the light emitting diode 43.

  In addition, the second carriage 36 cancels the overlap of the optical path due to the return of the light by the second mirror 44b and the third mirror 44c, so that the first carriage 35 has a speed that is half the speed of the first carriage 35, that is, a speed of V / 2. It travels in the same direction as the carriage 35, and the second carriage 36 travels at a travel distance (L / 2) that is half the travel distance L of the first carriage 35.

  Due to this travel speed relationship, even if the first carriage 35 and the second carriage 36 travel, the optical path length of light from the document surface to the lens unit 37 does not change.

  On the other hand, the drive wire 33 includes two systems that are wound around the wire drive pulley 34 and extend in the left direction and the right direction. A portion 33a of the drive wire extending in the left direction is folded back by an idler pulley 41 whose shaft is fixed to the main body frame 31, reaches a portion 33b, reaches the outer carriage pulley 40b, and is folded again here to become a portion 33c. The part is fixed to the idler pulley 41.

  Further, the portion 33d of the drive wire 33 extending rightward is folded back by an idler pulley 42 fixed to the main body frame 31 to become a portion 33e to reach the inner carriage pulley 40a, where it is folded back again to become a portion 33f. It is fixed to the idler pulley 42 via a tension spring 39 as a spring member.

  Further, a home position sensor (not shown) is provided on the left side in FIG. 2, and a first motor 35 travels to the left side in FIG. 2 and passes through the home position sensor to drive a drive shaft 32. When driven only by pulses, the motor is stopped.

  At this time, the wire drive pulley 34 is stopped via the drive shaft 32. This position becomes the home position position of the first carriage 35. When the reading of the document is finished, the first carriage 35 always travels to the home position position and travel is started again from this position.

  In addition, the first carriage 35 and the second carriage 36 of the present embodiment travel in the scanning direction on the right side in FIG. When returning to the position, the vehicle travels in the return direction on the left side in FIG.

  When the vehicle travels in the return direction, it is not affected by the reading speed of the document, and therefore travels at a high speed in order to increase the productivity of the document.

  In the copying machine 10 having such a configuration, the first carriage 35 and the second carriage 36 are moved in the main scanning direction to irradiate the original P with light from the light emitting diode 43. At this time, part of the light emitted from the light emitting diode 43 is reflected by the reflector 53 to the original P. As a result, the document P is irradiated with light within the range indicated by the irradiation region E.

  The reflected light from the document P is turned back in the order of the first mirror 44 a, the second mirror 44 b and the third mirror 44 c, then enters the lens unit 37, and is imaged placed on the focal plane by the imaging lens of the lens unit 37. A focused image is formed on element 57. Thereby, the image sensor 57 scans the line on the document along the light emitting diode 43 in the main scanning direction and the sub scanning direction.

  Further, as the first carriage 35 travels, light is emitted from the light emitting diode 43 to the irradiation region E. The position of the irradiation region E with respect to the light irradiation device 50 and the traveling position of the first carriage 35 are shown in FIG. Thus, the positional relationship is always constant.

  In the present embodiment, the circuit board 51 is installed between the light emitting diode 43 and the contact glass 15, and the light emitting diode 43 is installed at a position away from the end 51 a on the irradiation region E side of the circuit board 51. Since the light shielding part 51b extending from the holding surface of the light emitting diode 43 toward the irradiation area E is formed on the circuit board 51, the direct light irradiated outside the irradiation area E can be shielded by the light shielding part 51b. .

  Therefore, the irradiation light from the light emitting diode 43 can be guided to the irradiation area E, and the original P can be read satisfactorily with the irradiation distribution on the irradiation area E uniform.

  Further, the light shielding part 51b can be formed with a simple structure by installing the light emitting diode 43 on the lower surface of the circuit board 51 and installing the light emitting diode 43 at a position separated from the end part 51a on the irradiation region E side. Therefore, it is possible to prevent the manufacturing cost of the light irradiation device 50 from increasing. As a result, it is possible to prevent the manufacturing cost of the copying machine 10 from increasing.

  In the present embodiment, the holding surface of the circuit board 51 with respect to the light emitting diode 43 extends in a direction substantially perpendicular to the irradiation surface 43 a of the light emitting diode 43. The light shielding part 51b can be positioned upward.

  For this reason, a part of the light emitted from the light emitting diode 43 can be surely shielded by the light shielding part 51b to guide the light to the irradiation region E, and the irradiation distribution on the irradiation region E can be made uniform. .

  In the present embodiment, the light emitting diode 43 is positioned outward from one end portion in the sub-scanning direction with respect to the irradiation region E, and the end portion 51a of the circuit board 51 is substantially orthogonal to the holding surface of the circuit board 51. Is positioned on the line b connecting the extending direction end of the irradiation surface 43 a of the light emitting diode 43 and the one end portion of the irradiation region E in the sub-scanning direction, and therefore, with respect to the irradiation surface 43 a of the light emitting diode 43. Thus, the light shielding part 51b can be positioned upward. For this reason, a part of the light emitted from the light emitting diode 43 can be surely shielded by the light shielding part 51b to guide the light to the irradiation region E, and the irradiation distribution on the irradiation region E can be made uniform. .

  Further, in the present embodiment, since the circuit board 51 is composed of a light shielding member, unnecessary light can be reliably blocked by the light shielding portion 51b, and unintended light other than the irradiation region E is irradiated. Can be prevented. For this reason, the original P can be read satisfactorily by making the irradiation distribution on the irradiation region E uniform.

  In this embodiment, since a plurality of light emitting diodes 43 are provided along the main scanning direction of the document, the amount of irradiation light can be increased, and when used in the copying machine 10 employing a reduction optical system. Even when the distance from the document surface to the image sensor 57 is long, the light irradiated to the irradiation area E can reach the image sensor 57, and the reading accuracy of the document P can be prevented from being lowered. it can.

  In the present embodiment, the circuit board 51 is composed of a light shielding member, but the surface of the light shielding part 51b may be black as shown in FIG. If it does in this way, it will be easy to absorb irradiation light by the light shielding part 51b, and irradiation light which passes the light shielding part 51b can be decreased. For this reason, it is possible to prevent unintentional light other than the irradiation area E from being irradiated, and to uniformly read the original P by making the irradiation distribution on the irradiation area E uniform.

  Further, the same effect can be obtained even when the surface of the light shielding portion 51b on the holding surface side of the light emitting diode 43 is made black instead of making the entire surface of the light shielding portion 51b black.

  Further, in the present embodiment, when the distance between the end 51a of the circuit board 51 and the contact glass 15 is made constant, the position of the light emitting diode 43 with respect to the circuit board 51 is adjusted so that the irradiation region in the sub-scanning direction is adjusted. The width, that is, the width in the sub-scanning direction of the reading area of the document P can be adjusted.

Hereinafter, a specific description will be given based on FIGS. 4, 7, and 8.
First, in order to increase the width of the irradiation region by increasing the width in the sub-scanning direction, the light emitting diode 43 is installed at the first holding position in the vicinity of the end portion 51a on the irradiation region E1 side of the circuit board 51 as shown in FIG. To do.

  In this way, since the length of the light shielding part 51b can be shortened, the amount of light shielding can be reduced. For this reason, as shown by a, the width of the irradiation region E1 in the sub-scanning direction can be widely adjusted while shielding the direct light irradiated to other than the irradiation region E1 by the light shielding part 51b.

  In order to narrow the irradiation region by narrowing the width in the sub-scanning direction, as shown in FIG. 8, the light emitting diode 43 is moved from the first holding position in the vicinity of the end portion 51a on the irradiation region E2 side of the circuit board 51. It is installed at a second holding position that is spaced away from the irradiation area.

  In this way, since the length of the light shielding part 51b can be increased, the amount of light shielding can be increased. For this reason, as shown by a, the width of the irradiation region E2 in the sub-scanning direction can be narrowly adjusted while shielding the direct light irradiated to other than the irradiation region E2 by the light shielding part 51b.

  In order to make the width in the sub-scanning direction the width between the irradiation areas E1 and E2, as shown in FIG. 4, the light emitting diode 43 is connected to the first vicinity of the end 51a of the circuit board 51 on the irradiation area E side. It is installed at a third holding position between the holding position and a second holding position that is separated from the vicinity of the end 51a on the irradiation area E side in the direction opposite to the irradiation area E.

In this way, the length of the light shielding part 51b can be made to be the length between the light shielding parts 51b shown in FIGS. The width of the irradiation area E in the sub-scanning direction can be adjusted to the width between the irradiation area E1 and the irradiation area E2 while being shielded by the light shielding portion 51b.
Thus, by adjusting the installation position of the light emitting diode 43 from the end portion 51a of the circuit board 51, the irradiation region can be adjusted to an arbitrary width.

  9 to 12 are diagrams showing a second embodiment of the light irradiation apparatus, the image reading apparatus, and the image forming apparatus according to the present invention. The same reference numerals are given to the same components as those in the first embodiment. Therefore, the description is omitted.

  In FIG. 9, a circuit board 51 is attached to a base plate 35a via a holding member and a bracket 61 as a mounting member. A light emitting diode 43 as a light emitting element is attached to the circuit board 51 in the main scanning direction of the document. Several are attached along. In the present embodiment, the light emitting diode 43, the circuit board 51, the bracket 61, the reflector 53, and the first traveling body 35 constitute the light irradiation device 60.

  The holding surface of the bracket 61 with respect to the circuit board 51 extends in a direction substantially perpendicular to the irradiation surface 43 a of the light emitting diode 43. In addition, the holding surface of the bracket 61 is a surface on the side where the circuit board 51 is attached, and is the entire back surface of the inclined portion 61a of the bracket 61 in FIG. The holding position of the bracket 61 is a position where the circuit board 51 and the light emitting diode 43 are fixed to the bracket 61 on the holding surface of the bracket 61.

Further, the bracket 61 is disposed so as to be positioned between the circuit board 51 and the contact glass 15, and the light emitting diode 43 is disposed below the inclined portion 61 a of the bracket 61.
The light emitting diode 43 is attached to the end 51 a side of the circuit board 51, and the light emitting diode 43 and the circuit board 51 are separated from the end 61 b on the irradiation area E side of the bracket 61 in the opposite direction to the irradiation area E. It is installed at a holding position on the holding surface 61.

  Therefore, the bracket 61 is formed with a light shielding portion 61c (indicated by hatching) extending from the holding position of the light emitting diode 43 and the circuit board 51 toward the irradiation region E.

  Further, the end 61b of the bracket 61 is located at one end in the sub-scanning direction with respect to the irradiation area E, that is, outward from the right end of the irradiation area E in FIG. 9, and the end 61b of the bracket 61 is An extending direction end portion of the irradiation surface 43a of the light emitting diode 43 extending in a direction substantially orthogonal to the holding surface of the bracket 61, that is, a lower end portion of the irradiation surface 43a and an end portion in the sub-scanning direction of the irradiation region E in FIG. Is located on the line b connecting.

  Accordingly, light leaks by the light shielding portion 61c of the bracket 61 to the right in the sub travel direction with respect to the irradiation region E, that is, in the direction in which the first carriage 35 travels to the sub scanning side, as indicated by a in FIG. Can be prevented.

  The bracket 61 is made of a light shielding member that has a high light density and hardly transmits light, such as a polyester film containing carbon or PET material, and can reliably shield light by the light shielding portion 61c. It is like that.

  As described above, in the present embodiment, the light emitting diode 43 and the circuit board 51 are installed at positions separated from the end portion 61b of the bracket 61 on the irradiation region E side in the direction opposite to the irradiation region E. Since the light shielding part 61c extending from the holding surface of the circuit board 51 toward the irradiation area E is formed, the direct light irradiated outside the irradiation area E can be shielded by the light shielding part 61c.

  Therefore, the irradiation light from the light emitting diode 43 can be guided to the irradiation area E, and the original P can be read satisfactorily with the irradiation distribution on the irradiation area E uniform.

  Further, the light-emitting diode 43 and the circuit board 51 are installed on the lower surface of the bracket 61, and the light-emitting diode 43 and the circuit board 51 are installed at a position separated from the end portion 61b on the irradiation region E side. Since the part 61c can be formed, it can prevent that the manufacturing cost of the light irradiation apparatus 60 increases. As a result, it is possible to prevent the manufacturing cost of the copying machine 10 from increasing.

  In the present embodiment, the holding surface of the bracket 61 with respect to the circuit board 51 extends in a direction substantially perpendicular to the irradiation surface 43a of the light emitting diode 43, so that the light is irradiated to the irradiation surface 43a of the light emitting diode 43. The shielding part 61c can be positioned upward.

  For this reason, a part of the light emitted from the light emitting diode 43 can be reliably shielded by the light shielding part 61c, and the light can be guided to the irradiation region E, and the irradiation distribution on the irradiation region E can be made uniform. .

  Further, in the present embodiment, the end portion 61 b of the bracket 61 is positioned outward from one end portion in the sub-scanning direction with respect to the irradiation region E, and the end portion 61 b of the bracket 61 is substantially orthogonal to the holding surface of the bracket 61. Since the light emitting diode 43 extending in the direction is positioned on the line b connecting the extending direction end of the irradiation surface 43 a of the light emitting diode 43 and the one end of the irradiation region E in the sub-scanning direction, On the other hand, the light shielding part 61c can be positioned upward. For this reason, a part of the light emitted from the light emitting diode 43 can be reliably shielded by the light shielding part 61c, and the light can be guided to the irradiation region E, and the irradiation distribution on the irradiation region E can be made uniform. .

  Moreover, in this Embodiment, since the bracket 61 was comprised from the light shielding member, unnecessary irradiation light can be reliably interrupted | blocked by the light shielding part 61c, and unintended light other than the irradiation area | region E is irradiated. Can be prevented. For this reason, the original P can be read satisfactorily by making the irradiation distribution on the irradiation region E uniform.

  In the present embodiment, the bracket 61 is made of a light shielding member, but the surface of the light shielding portion 61c on the holding surface side of the circuit board 51 may be black as shown in FIG. If it does in this way, it will be easy to absorb irradiation light by the light shielding part 61c, and irradiation light which passes the light shielding part 61c can be decreased. For this reason, it is possible to prevent unintentional light other than the irradiation area E from being irradiated, and to uniformly read the original P by making the irradiation distribution on the irradiation area E uniform.

  In the present embodiment, the width of the irradiation region in the sub-scanning direction is adjusted by adjusting the position of the light emitting diode 43 with respect to the circuit board 51 when the distance between the end 61b of the bracket 61 and the contact glass 15 is constant. That is, the width in the sub-scanning direction of the reading area of the document P can be adjusted.

Hereinafter, specific description will be given based on FIGS. 9, 11, and 12.
First, in order to increase the width of the irradiation region by increasing the width in the sub-scanning direction, the end portion 51a on the irradiation region E1 side of the circuit board 51 is replaced with the end portion of the bracket 61 on the irradiation region E1 side as shown in FIG. It is installed at the first holding position in the vicinity of 61b.

  In this way, since the length of the light shielding part 61c can be shortened, the amount of light shielding can be reduced. For this reason, as shown by a, the width of the irradiation region E1 in the sub-scanning direction can be broadly adjusted while the direct light irradiated to other than the irradiation region E1 is shielded by the light shielding part 11b.

  Further, in order to narrow the irradiation region by narrowing the width in the sub-scanning direction, as shown in FIG. 12, the end portion 51a on the irradiation region E2 side of the circuit board 51 is replaced with the end portion on the irradiation region E2 side of the bracket 61. It is installed at a second holding position that is separated from the first holding position near 61b in the direction opposite to the irradiation area.

  In this way, since the length of the light shielding part 61c can be increased, the amount of light shielding can be increased. For this reason, as shown by a, the width of the irradiation region E2 in the sub-scanning direction can be narrowly adjusted while shielding the direct light irradiated to other than the irradiation region E2 by the light shielding part 61c.

  Further, in order to make the width in the sub-scanning direction the width between the irradiation areas E1 and E2, as shown in FIG. 9, the end portion 51a on the irradiation area E2 side of the circuit board 51 is connected to the irradiation area E2 side of the bracket 61. Is installed at a third holding position between the first holding position in the vicinity of the end portion 61b and the second holding position spaced from the vicinity of the end portion 61b on the irradiation region E2 side in the direction opposite to the irradiation region E2.

  In this way, the length of the light shielding part 61c can be made to be the length between the light shielding parts 61a shown in FIGS. 11 and 12, so that the direct light irradiated outside the irradiation region E is light-shielded. The width of the irradiation region E in the sub-scanning direction can be adjusted to the width between the irradiation region E1 and the irradiation region E2 while being shielded by the part 61a.

Thus, by adjusting the installation position of the circuit board 51 and the light emitting diode 43 from the end portion 61 b of the bracket 61, the irradiation region can be adjusted to an arbitrary width.
In each of the above embodiments, a light emitting diode is used as a light emitting element, but an EL (Electronic Luminescent) may be used.

  As described above, the light irradiation apparatus, the image reading apparatus, and the image forming apparatus according to the present invention can make the irradiation distribution on the irradiation region uniform with a simple configuration and can read the irradiated object satisfactorily. An image reading apparatus such as a scanner apparatus having a light emitting element for irradiating the irradiated body with light in order to read the irradiated body such as a manuscript, and the image reading apparatus. It is useful as an image forming apparatus such as a facsimile machine, a copying machine, and a multi-function machine.

1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment of the image forming apparatus according to the present invention. FIG. 3 is a side view showing a positional relationship of each component of the image reading unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 2A is a schematic front view of an image reading unit of the first embodiment of the image forming apparatus according to the present invention, and FIG. 2B is a schematic perspective view of the image reading unit. It is a front view of the light irradiation apparatus of 1st Embodiment of the image forming apparatus which concerns on this invention. (A) is a block diagram of the bracket to which the light emitting diode and the circuit board of the first embodiment of the image forming apparatus according to the present invention are attached, and (b) is a perspective view thereof. It is a front view of the light irradiation apparatus of the other structure of 1st Embodiment of the image forming apparatus which concerns on this invention. It is a front view of the light irradiation apparatus of the other structure of 1st Embodiment of the image forming apparatus which concerns on this invention. It is a front view of the light irradiation apparatus of the other structure of 1st Embodiment of the image forming apparatus which concerns on this invention. It is a front view of the light irradiation apparatus of 2nd Embodiment of the image forming apparatus which concerns on this invention. It is a front view of the light irradiation apparatus of the other structure of 2nd Embodiment of the image forming apparatus which concerns on this invention. It is a front view of the light irradiation apparatus of the other structure of 2nd Embodiment of the image forming apparatus which concerns on this invention. It is a front view of the light irradiation apparatus of the other structure of 2nd Embodiment of the image forming apparatus which concerns on this invention. It is a schematic block diagram of the conventional image reading apparatus. It is a front view of the conventional light irradiation apparatus provided with the xenon lamp. It is a front view of the conventional light irradiation apparatus provided with the light emitting diode. It is a perspective view of the conventional light irradiation apparatus provided with the light emitting diode. It is a figure which shows ideal illumination intensity distribution when light is irradiated to the irradiation area | region from the light emitting diode of the conventional light irradiation apparatus. It is a figure which shows actual illuminance distribution when light is irradiated to the irradiation area | region from the light emitting diode of the conventional light irradiation apparatus.

Explanation of symbols

10 Copying machine (image forming device)
13 Image reading unit (image reading device)
14 Image forming unit (image forming means)
15 Contact glass (transparent material)
43 Light Emitting Diode (Light Emitting Element)
50, 60 Light irradiation device 51 Circuit board (holding member, light shielding member)
51a edge (irradiation area side edge)
51b Light shielding part 61 Bracket (holding member, mounting member, light shielding member)
61b end (irradiation area side end)
61c Light shielding part E, E1, E2 Irradiation area P Original (irradiated body)

Claims (16)

Light having a light emitting element that irradiates light to an irradiation region in a certain range of the transparent member and irradiates an irradiated object existing on the transparent member through the transparent member, and a holding member that holds the light emitting element at a holding position. In the irradiation device,
The holding member is disposed between the light emitting element and the transparent member, and the light emitting element is disposed at a holding position separated from the irradiation region side end of the holding member in a direction opposite to the irradiation region. A light irradiation apparatus, wherein a light shielding portion extending from the holding position of the light emitting element toward the irradiation region is formed on the member. The light irradiation apparatus according to claim 1, wherein the holding member is made of a circuit board that drives the light emitting element. A circuit board for holding the light emitting element and driving the light emitting element;
The light irradiation apparatus according to claim 1, wherein the holding member includes a mounting member that can be mounted on an image reading apparatus while holding the circuit board at the holding position. The light emitting device according to claim 2, wherein the light emitting element is installed at a first holding position in the vicinity of an irradiation region side end of the circuit board. 3. The light irradiation according to claim 2, wherein the light emitting element is installed at a second holding position that is spaced apart from the first holding position near the irradiation region side end of the circuit board in a direction opposite to the irradiation region. apparatus. The light emitting element has a third holding position between a first holding position in the vicinity of the irradiation region side end portion of the circuit board and a second holding position separated from the irradiation region side end portion in the opposite direction to the irradiation region. The light irradiation apparatus according to claim 2, wherein the light irradiation apparatus is installed in the apparatus. The light irradiation apparatus according to claim 3, wherein the irradiation region side end portion of the circuit board is installed at a first holding position in the vicinity of the irradiation region side end portion of the mounting member. The irradiation region side end of the circuit board is installed at a second holding position that is spaced apart from the first holding position in the vicinity of the irradiation region side end of the mounting member in a direction opposite to the irradiation region. 3. The light irradiation apparatus according to 3. The irradiation region side end of the circuit board is separated from the first holding position in the vicinity of the irradiation region side end of the mounting member and from the vicinity of the irradiation region side end of the mounting member in a direction opposite to the irradiation region. The light irradiation apparatus according to claim 3, wherein the light irradiation apparatus is installed at a third holding position between the positions. The light irradiation according to any one of claims 1 to 9, wherein a holding surface of the holding member that holds the light emitting element extends in a direction substantially perpendicular to an irradiation surface of the light emitting element. apparatus. The light emitting element is located outward from one end in the sub-scanning direction with respect to the irradiation region,
The irradiation region side end portion of the holding member connects the extending direction end portion of the light emitting element extending in a direction substantially orthogonal to the holding surface and the one end portion of the irradiation region in the sub-scanning direction. It is located on a line | wire, The light irradiation apparatus of any one of Claims 1-10 characterized by the above-mentioned. The light irradiation apparatus according to claim 1, wherein at least the light shielding portion surface on the holding surface side of the light emitting element is blackened. The light irradiation apparatus according to claim 2, wherein the holding member is formed of a light shielding member. The light emitting device according to any one of claims 1 to 13, wherein a plurality of the light emitting elements are provided along a main scanning direction of the irradiated object. An image reading apparatus comprising the light irradiation device according to claim 1. An image forming apparatus comprising: an image forming unit that forms an image on a recording medium; and the image reading apparatus according to claim 15.

Images