JP2022034763A - Document reading device - Google Patents

Abstract

To reduce the thickness of a document reading device.SOLUTION: A document reading device 60 comprises: a contact glass 81 that has a contact surface 81a brought into contact with a document 95; a light source 82 that irradiates the document 95 with light through the contact glass 81; and an image reading element 83 that receives light reaching the document 95 and reflected thereon. The contact glass 81 has a first inclined surface 81b that is inclined with respect to the contact surface 81a, and a second inclined surface 81c that is opposite to the first inclined surface 81b. The light source 82 is arranged closer to the first inclined surface 81b side. The first inclined surface 81b guides the light incident from the light source 82 to the second inclined surface 81c. The second inclined surface 81c guides the light incident from the first inclined surface 81b in a direction in which the document 95 can be irradiated with the light.SELECTED DRAWING: Figure 3

Description

The present invention relates to a document reader.

Conventionally, there has been known a document reading device that irradiates a document placed on a contact glass with light and reads the reflected light from the document with an image reading element. Patent Document 1 includes a light guide plate having a first emission surface that directly irradiates the reading region with light from a light source and a second emission surface that irradiates the reading region via a counter-reflective member, and is different from each other. A document reading device that irradiates a reading region with light from a direction is disclosed.

Japanese Unexamined Patent Publication No. 2013-90268

However, in the document reading device described in Patent Document 1, it is necessary to dispose a light guide plate and a counter-reflective member between the contact glass and the image reading element, and it is difficult to further reduce the thickness of the device.

The document reading device includes a contact glass having a contact surface in contact with the document, a light source that irradiates the document with light through the contact glass, and an image reading element that receives the reflected light of the light that reaches the document. The contact glass has a first inclined surface that is inclined with respect to the contact surface and a second inclined surface that faces the first inclined surface, and the light source is directed to the first inclined surface side. The first inclined surface is arranged to guide the light incident from the light source to the second inclined surface, and the second inclined surface irradiates the document with the light incident from the first inclined surface. Guide in the possible direction.

The perspective view which shows the appearance of the recording apparatus which includes the document reading apparatus which concerns on Embodiment 1. FIG. Schematic cross-sectional view showing an outline of the internal configuration of a recording device. Schematic cross-sectional view showing the configuration of a CIS module. The schematic cross-sectional view which shows the structure of the CIS module which the document reading apparatus which concerns on Embodiment 2 has. The schematic cross-sectional view which shows the structure of the CIS module which the document reading apparatus which concerns on Embodiment 3 has.

1. 1. Embodiment 1
The schematic configuration of the document reading apparatus 60 according to the first embodiment will be described. The document reading device 60 is, for example, a scanner provided in a recording device 11 that records on a medium 90 by an inkjet method, and reads a document 95 on which an image, characters, or the like is recorded. In the coordinates shown in the drawings, assuming that the recording device 11 is placed on a horizontal plane, three virtual axes orthogonal to each other are defined as an X-axis, a Y-axis, and a Z-axis. The Y-axis is an axis parallel to the front-rear direction of the recording device 11, and the tip end side of the arrow indicating the Y-axis is defined as "front". The X-axis is an axis parallel to the left-right direction of the recording device 11, and the tip end side of the arrow indicating the X-axis is "left". The Z-axis is an axis parallel to the vertical direction, and the tip end side of the arrow indicating the Z-axis is "up". Further, the tip end side of the arrow indicating each axis is the "+ direction", and the base end side is the "-direction".

As shown in FIGS. 1 and 2, the recording device 11 includes a housing 14 having a shape like a substantially square box long in the X direction, and legs 13 for supporting the housing 14. Further, the recording device 11 has a medium transport unit 45 that transports the medium 90 in the transport direction along the + Y direction, and a recording unit 50 that records on the medium 90. Further, the recording device 11 includes a document reading device 60 for reading characters and images recorded on the document 95. The medium transport unit 45 and the recording unit 50 are provided inside the housing 14. The document reading device 60 has a long box shape in the X direction and is provided in front of the recording unit 50 in the housing 14.

On the upper surface of the housing 14, a rectangular viewing window 29 long in the X direction is provided so that the recording unit 50 can be visually recognized. The peephole 29 has a peephole 30 that opens in the + Z direction and a peephole cover 31 that covers the peephole 30. One end of the peephole cover 31 in the −Y direction is rotatably supported, and the other end in the + Y direction opens and closes along the Z axis.

The housing 14 includes a holding unit 33 that detachably holds a liquid container that stores a liquid such as ink, an operating unit 34 for operating the recording device 11, and a long printing medium 90. A storage unit 35 that can be stored is provided. The holding portion 33 is provided in the lower front portion of the housing 14 in the + Y direction. The operation unit 34 is provided at the right end of the upper surface of the housing 14.

The accommodating portion 35 is provided in the housing 14 so as to project in the + Z direction from the end portion on the −Y direction side. The accommodating portion 35 is configured to accommodate a medium roll 91 formed by winding the medium 90 in a roll shape. The accommodating portion 35 has a support portion 37 that supports the medium roll 91 so that it can rotate about the axis of the medium roll 91. The medium 90 is unwound from the medium roll 91 and unwound into the housing 14 by rotationally driving the medium roll 91 by a drive motor.

The housing 14 has an accommodating portion cover 40 that covers the front and the upper part of the accommodating portion 35 so as to be openable and closable. By opening the accommodating portion cover 40, the medium roll 91 can be replaced.

The housing 14 has a medium discharge port 55 from which the medium 90 printed by the recording unit 50 is discharged. The medium discharge port 55 opens in the + Y direction on the front surface of the housing 14. The medium ejection port 55 is located between the document reading device 60 and the holding portion 33, and extends along the X direction.

The housing 14 includes a guide plate 56 that supports the medium 90 discharged from the medium discharge port 55 from below. The guide plate 56 protrudes in the + Y direction from below the medium discharge port 55, and is inclined so as to go down in the −Z direction toward the + Y direction.

As shown in FIG. 2, the medium transport section 45 transports the medium 90 unwound from the medium roll 91 housed in the storage section 35 in the + Y direction, which is the transport direction of the medium 90. The medium transport section 45 is provided on the upstream side of the recording section 50 in the transport direction of the medium 90. The medium transfer unit 45 includes a medium transfer roller 46 having a rotation axis longer than the width of the medium 90 along the X axis, and a medium transfer motor for driving the medium transfer roller 46.

The recording unit 50 records images, characters, and the like on the medium 90 transported by the medium transport unit 45. The recording unit 50 has a guide shaft 51 extending along the X axis, a carriage 52 supported by the guide shaft 51, and a carriage motor for reciprocating the carriage 52 along the guide shaft 51. The carriage 52 is equipped with a recording head 54 that faces the medium 90 and discharges the liquid toward the medium 90.

The medium 90 conveyed by the medium transfer unit 45 passes through the −Z side facing the recording head 54 along the transfer direction. The recording head 54 reciprocates along the X-axis and discharges the liquid in the −Z direction. In the recording unit 50, a liquid is discharged from the recording head 54, and the liquid adheres to the medium 90 to perform recording.

In the present embodiment, the serial type recording head 54 is exemplified, but the present invention is not limited to this, and a line type head that extends over the entire width of the medium 90 in the X direction may be used.

The configuration of the document reading device 60 will be described.
As shown in FIGS. 1 and 2, the document reading device 60 has a document insertion slot 61 into which the document 95 is inserted, and a document transfer unit 62 for transporting the document 95 inserted from the document insertion slot 61 along the transport direction. It has a reading unit 63 for reading the document 95 conveyed by the document conveying unit 62, and a document ejection port 64 for ejecting the document 95 read by the reading unit 63.

The document reading device 60 has a fixing portion 67 fixed to the inside of the housing 14, and a reading portion cover 68 that is openable and closable to the fixing portion 67. In the document reading device 60, the transport path of the document 95 from the document insertion port 61 to the document ejection port 64 is used as a space between the fixed portion 67 and the reading section cover 68 when the reading section cover 68 is closed. It is composed.

The reading unit cover 68 has a square plate shape that is long in the X direction, and forms the front surface of the housing 14 in the closed state. The reading unit cover 68 has a rotating shaft 683 located at one end of the reading unit cover 68 in the −Z direction and extending along the X axis. The reading unit cover 68 is rotatably supported along the Z direction about the axis of the rotating shaft 683.

The document insertion slot 61 is a slit-shaped opening provided on the upper surface of the housing 14 and long in the X direction. The document 95 is placed on the upper surface of the housing 14 behind the document insertion slot 61. The document 95 inserted from the document insertion slot 61 enters the inside of the housing 14 diagonally forward and downward, and is conveyed by the document transfer unit 62 in the −Z direction, which is the transfer direction of the document 95.

The document transport section 62 includes a first transport mechanism 73 and a second transport mechanism 77 located downstream of the first transport mechanism 73 in the transport direction of the document 95. The document transfer unit 62 has a document transfer motor that drives the first transfer mechanism 73 and the second transfer mechanism 77.

The first transport mechanism 73 includes a first drive roller 74, a first driven roller 75, and a second driven roller 76. The first drive roller 74 is provided on the fixed portion 67. The first driven roller 75 and the second driven roller 76 are provided on the reading unit cover 68. With the reading cover 68 closed, the first driven roller 75 and the second driven roller 76 face the first driven roller 74. The first driven roller 75 is provided on the upstream side of the second driven roller 76 in the transport direction of the document 95.

The first drive roller 74 has a rotation axis extending along the X direction, and is rotatably supported by the fixing portion 67. A plurality of first drive rollers 74 are provided with respect to the rotation axis, and are arranged at predetermined intervals along the X direction. The first drive roller 74 is driven by a document transfer motor. The first driven roller 75 and the second driven roller 76 have a rotation axis extending along the X direction, and are rotatably supported by the reading unit cover 68. A plurality of the first driven roller 75 and the second driven roller 76 are provided with respect to the rotation axis, and are arranged at predetermined intervals along the X direction.

The first transport mechanism 73 is configured to be able to hold the document 95 by sandwiching the document 95 between the first drive roller 74 and the first driven roller 75. The first drive roller 74 and the first driven roller 75 hold the document 95 inserted from the document insertion slot 61. For example, when the document 95 has a predetermined thickness, the separation distance between the outer peripheral surface of the first drive roller 74 and the outer peripheral surface of the first driven roller 75 may be smaller than the thickness of the document 95. Further, in a state where the document 95 does not exist, the outer peripheral surface of the first drive roller 74 and the outer peripheral surface of the first driven roller 75 may be in contact with each other. Of the first drive roller 74 and the first driven roller 75, at least the outer peripheral surface of the first drive roller 74 may be covered with a member capable of elastic deformation, such as natural rubber or synthetic rubber.

The second transport mechanism 77 has a second drive roller 78 and a third driven roller 79. The second drive roller 78 is provided on the fixed portion 67. The third driven roller 79 is provided on the reading unit cover 68. With the reading unit cover 68 closed, the third driven roller 79 faces the second drive roller 78. The second drive roller 78 has a rotation axis extending along the X direction, and is rotatably supported by the fixing portion 67. A plurality of second drive rollers 78 are provided with respect to the rotation axis, and are arranged at predetermined intervals along the X direction. The second drive roller 78 is driven by a document transfer motor.

The third driven roller 79 has a rotation axis extending along the X direction and is rotatably supported by the reading unit cover 68. A plurality of third driven rollers 79 are provided with respect to the rotation axis, and are arranged at predetermined intervals along the X direction.

The reading unit 63 is provided between the first transport mechanism 73 and the second transport mechanism 77 in the transport direction of the document 95. The reading unit 63 is provided on the reading unit cover 68. The reading unit 63 faces the document 95 to be conveyed along the conveying direction in a state where the reading unit cover 68 is closed. The details of the reading unit 63 will be described later.

The housing 14 has a document ejection port 64 into which the document 95 read by the reading unit 63 is ejected. The document ejection port 64 opens in the + Y direction on the front surface of the housing 14. The document ejection port 64 is located between the reading section cover 68 and the medium ejection port 55 in a state where the reading section cover 68 is closed, and extends along the X direction. The fixing portion 67 includes a flap 85 that supports the document 95 ejected from the document ejection port 64 from below. The flap 85 projects in the + Y direction from below the document ejection port 64, and is inclined so as to descend in the −Z direction toward the + Y direction. Further, the reading unit cover 68 includes a guide roller 86. The document 95, which is conveyed in the −Z direction by the document transfer unit 62, is ejected by the guide roller 86 and the flap 85 while changing the direction in the + Y direction.

The reading unit 63 has a plurality of contact image sensor (CIS) modules 80. The CIS module 80 of the present embodiment has a long rod shape in the X direction, and is configured to be capable of collectively reading the original document 95 within a size range along the X direction. In the document reading device 60, a plurality of CIS modules 80 are arranged along the X direction and in a state in which some of them overlap each other in the Z direction.

As shown in FIG. 3, the CIS module 80 includes a contact glass 81 in contact with the document 95, a light source 82 for irradiating the document 95 with light, and an image reading element 83 for receiving the reflected light of the light reaching the document 95. .. The CIS module 80 supports a contact glass 81 and includes a housing 89 that houses a light source 82 and an image reading element 83. The contact glass 81 supported by the housing 89 forms a part of the housing 89.

The light source 82 is composed of a plurality of LEDs arranged in a line along the X direction, which is the width direction of the document 95. The light source 82 irradiates the original document 95 with white light through the contact glass 81. The image reading element 83 is composed of a plurality of light receiving elements such as CMOS sensors arranged in a line along the X direction. The image reading element 83 has red, blue, and green color filters. The image reading element 83 receives the reflected light from the document 95 and converts information such as images and characters of the document 95 into an electric signal.

The contact glass 81 has a contact surface 81a in contact with the original document 95, a first inclined surface 81b inclined with respect to the contact surface 81a, and a second inclined surface 81c facing the first inclined surface 81b. Further, the contact glass 81 has an inner surface 81d parallel to the contact surface 81a. The contact glass 81 has a long plate shape in the X direction. The contact surface 81a and the inner surface 81d are planes formed by the X-axis and the Z-axis. The first inclined surface 81b and the second inclined surface 81c are side surfaces that intersect the contact surface 81a and the inner surface 81d and extend in the X direction. The first inclined surface 81b is provided in the + Z direction, and the second inclined surface 81c is provided in the −Z direction. A gap is provided between the first inclined surface 81b and the housing 89, and between the second inclined surface 81c and the housing 89. The contact glass 81 can be formed of a transparent resin such as acrylic as well as glass.

The angle formed by the first inclined surface 81b and the inner surface 81d is equal to or greater than the critical angle. The angle formed by the second inclined surface 81c and the contact surface 81a is equal to or larger than the critical angle. The critical angle is the smallest angle of incidence at which total internal reflection occurs at the interface when light travels from the glass layer of the contact glass 81 to the air layer. That is, light incident at an incident angle equal to or higher than the critical angle is totally reflected without being transmitted at the boundary surface. The critical angle from the glass layer to the air layer is about 41 to 43 degrees. The angle formed by the first inclined surface 81b and the inner surface 81d and the angle formed by the second inclined surface 81c and the contact surface 81a are different angles even if they are the same angle as long as they are at least the critical angle. May be.

The light source 82 faces the original document 95 via the contact glass 81 in the Y direction, and is arranged on the first inclined surface 81b side between the first inclined surface 81b and the second inclined surface 81c in the Z direction. The image reading element 83 faces the original document 95 via the contact glass 81 in the Y direction, and is arranged on the second inclined surface 81c side between the first inclined surface 81b and the second inclined surface 81c in the Z direction.

The contact glass 81 has a function of a light guide plate that guides the light emitted from the light source 82 to the image reading element 83 on the opposite side of the light source 82 in the Z direction.
Specifically, as shown in the second optical path 82b in FIG. 3, a part of the light emitted from the light source 82 travels in the −Y direction, passes through the inner surface 81d of the contact glass 81, and passes through the first inclined surface 81b. To reach. At this time, since the incident angle of the light incident on the first inclined surface 81b is equal to or higher than the critical angle, the light is totally reflected by the first inclined surface 81b and its traveling direction is changed to the −Z direction. The light reflected by the first inclined surface 81b travels through the contact glass 81 while repeating total reflection, and reaches the second inclined surface 81c. That is, the first inclined surface 81b guides the light incident from the light source 82 to the second inclined surface 81c.

The second inclined surface 81c guides the light incident from the first inclined surface 81b in a direction capable of irradiating the document 95. Since the incident angle of the light incident on the second inclined surface 81c is equal to or higher than the critical angle, the light is totally reflected by the second inclined surface 81c and its traveling direction is changed to the −Y direction. The light reflected by the second inclined surface 81c passes through the contact surface 81a of the contact glass 81 and irradiates the surface of the original document 95 facing the image reading element 83 from the −Z direction. That is, the second inclined surface 81c guides the light incident from the first inclined surface 81b to the contact surface 81a.

As shown in the first optical path 82a of FIG. 3, a part of the light emitted from the light source 82 travels diagonally downward in the −Y direction and passes through the inner surface 81d and the contact surface 81a of the contact glass 81. The light transmitted through the contact surface 81a directly irradiates the surface of the document 95 facing the image reading element 83 from the + Z direction.

In this way, the image reading element 83 reads the reflected light of the light applied to the document 95 from two different directions, the + Z direction on the upstream side and the −Z direction on the downstream side in the transport direction of the document 95. The CIS module 80 of the present embodiment can irradiate light from the upstream side and the downstream side of the fold wrinkles even if the document 95 has fold wrinkles parallel to the direction intersecting the transport direction. As a result, the influence of shadows caused by fold wrinkles is reduced, and the reading accuracy of the document 95 is improved.

As described above, according to the document reading device 60 according to the present embodiment, the following effects can be obtained.
The document reading device 60 includes a contact glass 81 having first and second inclined surfaces 81b and 81c which are inclined surfaces having a critical angle or more. The light source 82 is provided on the side of the first inclined surface 81b. The contact glass 81 guides a part of the light emitted from the light source 82 from the first inclined surface 81b side to the second inclined surface 81c side, and the surface of the document 95 facing the image reading element 83 is referred to as the light source 82. Irradiate from the other side. As a result, the document 95 is irradiated from two directions, so that the reading accuracy of the document 95 is improved. Since the contact glass 81 has a function of a light guide plate that guides light from the first inclined surface 81b side to the second inclined surface 81c side, the device is made thinner than the configuration in which the light guide plates are individually provided. be able to.

The second inclined surface 81c guides the light incident from the first inclined surface 81b to the contact surface 81a, and irradiates the surface of the document 95 facing the image reading element 83 from the side opposite to the light source 82. As a result, the document 95 can be suitably irradiated from two directions.

2. 2. Embodiment 2
The configuration of the document reading device 160 according to the second embodiment will be described. The same components as those in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 4, the document reader 160 has a CIS module 180. The CIS module 180 includes a contact glass 81 in contact with the document 95, a light source 82 for irradiating the document 95 with light, and an image reading element 83 for receiving the reflected light of the light reaching the document 95.

A reflective member 87 for reflecting light is provided on the first inclined surface 81b and the second inclined surface 81c of the contact glass 81. The reflective member 87 is formed by attaching a mirror to the first and second inclined surfaces 81b and 81c, and by depositing or applying a metal such as aluminum or silver to the first and second inclined surfaces 81b and 81c. ..

As described above, since the document reading device 160 includes the reflecting member 87 that reflects the light emitted from the light source 82 on the first and second inclined surfaces 81b and 81c of the contact glass 81, the light from the contact glass 81 can be measured. The light guide efficiency can be improved.

3. 3. Embodiment 3
The configuration of the document reading device 260 according to the third embodiment will be described. The same components as those in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 5, the document reader 260 has a CIS module 280. The CIS module 280 includes a contact glass 281 in contact with the document 95, a light source 82 that irradiates the document 95 with light, a reflecting unit 284 that reflects the light, and an image reading element 83 that receives the reflected light of the light that reaches the document 95. To prepare for. The CIS module 280 includes a housing 289 that supports the contact glass 281 and houses a light source 82, an image reading element 83, and a reflector 284. The contact glass 281 supported by the housing 289 forms part of the housing 289.

The contact glass 281 is parallel to the contact surface 81a in contact with the original document 95, the first inclined surface 81b inclined with respect to the contact surface 81a, the second inclined surface 281c facing the first inclined surface 81b, and the contact surface 81a. It has an inner surface 81d. The first inclined surface 81b and the second inclined surface 281c are side surfaces that intersect the contact surface 81a and the inner surface 81d and extend in the X direction. The second inclined surface 281c is provided in the −Z direction. A gap is provided between the first inclined surface 81b and the housing 289, and between the second inclined surface 281c and the housing 289. The angle formed by the second inclined surface 281c and the inner surface 81d is equal to or larger than the critical angle. The first and second inclined surfaces 81b and 281c may be configured to include a reflecting member 87 that reflects light.

The reflecting unit 284 is arranged between the image reading element 83 and the second inclined surface 281c in the Z direction, and reflects the light incident from the second inclined surface 281c toward the document 95. The reflecting portion 284 can be configured by a mirror or the like.

The second inclined surface 281c guides the light incident from the first inclined surface 81b to the inner surface 81d which is a surface opposite to the contact surface 81a. Specifically, as shown in the second optical path 282b in FIG. 5, the incident angle of the light incident on the second inclined surface 281c is equal to or higher than the critical angle, so that the light is totally reflected by the second inclined surface 281c. The traveling direction is changed to the + Y direction. The light reflected by the second inclined surface 281c passes through the inner surface 81d of the contact glass 281 and reaches the reflecting portion 284. The light that has reached the reflecting portion 284 is totally reflected and its direction is changed to the −Y direction, and the light is transmitted through the contact glass 281 and irradiates the surface of the document 95 facing the image reading element 83 from the −Z direction.

In this way, the second inclined surface 281c guides the light incident from the first inclined surface 81b to the inner surface 81d. The light is totally reflected by the reflecting unit 284 and irradiates the document 95 from the side opposite to the light source 82 in the Z direction. As a result, the document 95 can be suitably irradiated from two directions. Since the contact glass 281 has a function of a light guide plate that guides light from the first inclined surface 81b side to the second inclined surface 281c side, the device is made thinner than the configuration in which the light guide plates are individually provided. be able to.

11 ... Recording device, 60, 160, 260 ... Original reading device, 80, 180, 280 ... CIS module, 81, 281 ... Contact glass, 81a ... Contact surface, 81b ... First inclined surface, 81c, 281c ... Second inclined Surface, 82 ... light source, 83 ... image reading element, 87 ... reflective member, 95 ... original, 284 ... reflective unit.

Claims (4)

A contact glass with a contact surface in contact with the document,
A light source that irradiates the original with light through the contact glass,
An image reading element that receives the reflected light of the light that reaches the document is provided.
The contact glass has a first inclined surface that is inclined with respect to the contact surface, and a second inclined surface that faces the first inclined surface.
The light source is arranged on the first inclined surface side.
The first inclined surface guides the light incident from the light source to the second inclined surface.
The second inclined surface guides the light incident from the first inclined surface in a direction capable of irradiating the document.
A document reader characterized by. The second inclined surface guides the light incident from the first inclined surface to the contact surface.
The document reading apparatus according to claim 1. The second inclined surface guides the light incident from the first inclined surface to the surface opposite to the contact surface.
Provided with a reflecting portion that reflects the light incident from the second inclined surface toward the document.
The document reading device according to claim 1. The first inclined surface and the second inclined surface are provided with a reflecting member that reflects the light.
The document reading device according to any one of claims 1 to 3, wherein the document reading device is characterized.

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