JP4605029B2 - Image sensor - Google Patents

Description

The present invention relates to an image sensor that irradiates a read medium such as a document with light, photoelectrically converts reflected light from the read medium, and outputs the photoelectric conversion to a control unit.

2. Description of the Related Art Conventionally, a copying machine or a multifunction machine equipped with an image reading device for reading an image recorded on a document is known. This image reading apparatus is a so-called flatbed scanner, which is a platen (original table) glass on which an original can be placed, and directly below the platen glass,
And an image sensor unit arranged to be able to reciprocate in parallel with the glass surface. Here, the image sensor unit is a CCD (Charge Coupled Device).
An image sensor having a substantially rectangular parallelepiped housing such as CIS (Contact Image Sensor) is mounted on a holding member (for example, a carriage).

In the image sensor unit described in Patent Document 1, an image sensor having a substantially rectangular parallelepiped housing is mounted on a holding member, and is arranged inside the image reading apparatus so that the upper surface 13 of the image sensor 12 faces upward. . This image sensor unit reads an image of a read medium such as a document with the longitudinal direction as the main scanning direction and the direction orthogonal to the main scanning direction as the sub-scanning direction (direction of arrow 11 in FIG. 12).

At this time, when the image sensor 12 is tilted in the longitudinal direction or rotated in the direction of the arrow 11 (short direction of the casing), the image sensor 12 is moved with respect to the platen glass on which the document is placed. As a result, the image cannot be accurately read from the original. Therefore, conventionally, roller units 6 </ b> A and 6 </ b> B for supporting smooth sliding are arranged at both ends of the image sensor 12.

FIG. 13 is an exploded perspective view of a main part of a conventional image sensor 12, in which the roller units 6 </ b> A and 6 </ b> B are separated from the image sensor 12. The roller unit 6B includes frames 7A and 7B and rollers 8 arranged at both ends of the frames 7A and 7B.
, 9. The frame 7B includes two engaging pins 10. However, FIG.
In FIG. 1, only one engagement pin 10 is shown because of the angle in the figure. The image sensor 12 includes two engagement holes 11 at the end thereof. The two engagement holes 11 have the above 2
By fitting the two engaging pins 10, the roller unit 6 </ b> B is moved to the image sensor 1.
2 is attached to one end. The roller unit 6A has the same configuration as the roller unit 6B. However, in FIG. 12, the engagement pin is not illustrated because of the angle of the drawing. These two engagement pins are provided in two engagement holes 13 provided at the end of the image sensor 12.
The roller unit 6 </ b> B is attached to the other end of the image sensor 12 by being fitted into the image sensor 12.

JP 2004-266314 A

By the way, in recent years, miniaturization of copying machines and multi-function machines has been promoted. In particular, in a multifunction machine or the like equipped with a flat bed type image reading apparatus, a CIS having a volume smaller than that of a CCD is often used as an image sensor. However, since this CIS has a very shallow depth of focus compared to a CCD, accuracy is required for the distance between the CIS and the platen glass. Therefore, in order to adjust the dimensional tolerance of each component, a thin plate-like adjustment member is often inserted between the roller unit and the image sensor.

However, the two engagement pins 10 protrude from the roller units 6A and 6B of Patent Document 1 and are fitted into the two engagement holes 11, 11 or 13, 13 provided on the upper surface 3 of the image sensor 12. Since it is configured, it is difficult to dispose a thin plate-shaped adjusting member. That is, after the roller units 6A and 6B are turned upside down and the pair of insertion holes provided in the adjustment member are inserted into the two engaging pins 10, the roller units 6A and 6B are turned upside down and the upper surface of the image sensor 12 is turned upside down. The two engagement pins 10 of the roller units 6A and 6B must be fitted into the two engagement holes 11, 11 or 13, 13 provided in 3, but the roller units 6 A, 6 B are placed on the image sensor 12. In this case, the adjustment member is a roller unit 6
There is a high possibility of dropping from A and 6B. In addition, the engagement holes 11 on the upper surface 3 of the image sensor 12,
11 or 13, 13 and the adjustment member is connected to the insertion hole of the adjustment member so that the adjustment member is connected to the image sensor 1.
2, the engaging pins 10 of the roller units 6A, 6B are moved to the engaging holes 11,
The reason why it is inserted into 11 or 13 or 13 is that the work is very fine and the assemblability deteriorates.

Accordingly, an object of the present invention is to provide an image sensor capable of improving the assemblability.

In order to achieve the above object, an image sensor according to claim 1 is a document table glass on which a document can be placed stationary, an image sensor unit capable of reciprocating along a lower surface of the document table glass, and the image sensor unit. An image sensor used in an image reading apparatus provided with a sensor unit and a roller that rolls in close contact with the lower surface of the platen glass, and a housing having a longitudinal direction, and a longitudinal direction of the housing A roller unit holding portion that can hold a roller unit that rotatably supports the roller, and is disposed between the housing and the roller unit. positioning member adjustable adjustment member the distance between the platen glass is provided on the roller unit holder and
The roller unit holding portions are stepped portions provided at both ends in the longitudinal direction of the casing.
The positioning member of the adjustment member is a protrusion protruding from the mounting surface constituting the step portion.
The adjustment member is positioned by inserting the protrusion into the insertion hole provided in the adjustment member.
-Decided fit is is characterized in Rukoto.

The image sensor according to claim 2 is the image sensor according to claim 1 , wherein the protrusion is inserted into a positioning hole provided in a bottom surface of the roller unit, so that the roller unit has the housing. It is characterized by being positioned with respect to the body.

According to a third aspect of the present invention, there is provided an image sensor, a platen glass on which a document can be placed stationary, and a glass platen.
An image sensor unit capable of reciprocating along the lower surface of the original platen glass and the image sensor
A roller that is disposed in the sensor unit and rolls in close contact with the lower surface of the platen glass.
An image sensor for use in an image reading apparatus, a casing having a longitudinal direction, and this
Roller units that are provided at both ends in the longitudinal direction of the housing and support the rollers rotatably.
A roller unit holding portion capable of holding, and disposed between the casing and the roller unit.
The distance between the image sensor and the platen glass can be adjusted.
A positioning member for the member is provided in the roller unit holding portion , the roller unit holding portion is a recess provided at both ends in the longitudinal direction of the housing, and the positioning member of the adjustment member is provided with the recess. They are a vertical surface and a mounting surface, and the adjustment member is positioned by being inserted into the concave portion.

Furthermore, the image sensor according to claim 4 is the image sensor according to claim 3 , wherein the protrusion protruding from the bottom surface of the roller unit is inserted into the positioning hole provided in the mounting surface. The roller unit is positioned with respect to the casing.

According to the first and third aspects of the invention, since the roller unit is attached to the housing of the image sensor after the adjustment member is positioned in the housing of the image sensor, the assemblability can be improved. As a result, not only the cost of the image sensor can be reduced, but also the cost of the image reading apparatus on which the image sensor is mounted can be expected.

According to the second and fourth aspects of the present invention, the roller unit can be positioned by the positioning member for positioning the adjustment member. Therefore, there is no need for another space for forming the positioning member for the roller unit, and the image sensor can be made compact. Can be

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

The specific devices and the like described below are merely examples of the embodiments of the present invention, and it is obvious that the embodiments of the present invention are not limited to the specific examples described in detail below. It is.

FIG. 1 is a perspective view showing an external configuration of an image reading apparatus according to an embodiment of the present invention, FIG. 2 is a plan view showing an internal configuration of a reading table, and FIG. 3 shows a main configuration of the reading table. Longitudinal section, Fig. 4
FIG. 5 is a perspective view showing the configuration of the image sensor unit according to the first embodiment, and FIG.
FIG. 6 is an exploded view of essential parts of the roller unit, FIG. 7 is an enlarged view of essential parts of the image sensor unit, and FIG. 8 is an enlarged top view of the image sensor unit. 9 is an enlarged side view of the image sensor unit, FIG. 10 is an exploded perspective view of the image sensor in the second embodiment, and FIG. 11 is a perspective view of the frame of the roller unit in the second embodiment viewed from the bottom plate side. FIG. 12 is a perspective view of a main part of a conventional image sensor unit, and FIG. 13 is an exploded perspective view of a main part of the image sensor unit shown in FIG.

  The configuration of the first embodiment according to the present invention will be described below.

The image reading apparatus 1 is used, for example, as a scanner unit of a multi-function device (MFD) having an integrated printer function and scanner function, or used as an image reading unit of a copying machine. However, the printer function or the like is an arbitrary mechanism in the present invention, and for example, the image reading apparatus 1 may be realized as a flatbed scanner (FBS: Flatbed Scanner) having only a scanner function.

As shown in FIG. 1, an image reading apparatus 1 has an original document cover 4 provided with an automatic document feeder (ADF) 3 attached to a reading table 2 functioning as an FBS so as to be freely opened and closed. It will be. In the reading table 2, a platen glass 21 that is a platen glass is disposed on the top surface of a substantially rectangular housing 20, and the image reading unit 5 is built in the housing 20. The upper surface of the platen glass 21 is a document placement surface. Therefore, when the image reading apparatus 1 is used as an FBS, first, a document as a medium to be read is placed on the platen glass 21, and the document pressing cover 4 is closed to fix the document. Subsequently, the image sensor unit 52 moves the platen glass 21 for reading a stationary document.
The original image is read by scanning the lower side of the original.

An operation panel 22 is provided on the front side of the reading table 2. Operation panel 22
Is composed of various operation buttons, a liquid crystal display unit, and the like, and the image reading apparatus 1 operates in accordance with instructions from the operation panel 22. When the image reading apparatus 1 is realized as an MFD, the image reading apparatus 1 operates according to an instruction transmitted from a connected computer via a scanner driver or the like in addition to an instruction from the operation panel 22.

The document pressing cover 4 is provided with an ADF 3 that continuously conveys documents from the document tray to the paper discharge tray. In the conveyance process by the ADF 3, the original passes through the moving original reading platen glass 23, and the image sensor unit 52 fixedly arranged below the platen glass 23 reads the image of the original. In the present invention, the ADF 3 has an arbitrary configuration.

The casing 20 of the reading table 2 includes a container-like lower frame 20A having an open top surface and an upper cover 20B having an opening for exposing the platen glasses 21 and 23 at the center. As shown in FIG. 2, the image reading unit 5 is disposed in the lower frame 20A.
The lower frame 20A and the upper cover 20B are both made of synthetic resin, and the lower frame 20
A shows a base portion 24 constituting a bottom plate, a side wall 25 rising from the periphery of the base portion 24, a portion where the image reading unit 5 is disposed, and a portion where the substrate of the operation panel 22 is disposed. A partition plate 26 to be partitioned is formed integrally. In the lower frame 20A,
Furthermore, a support rib for supporting the platen glass 21, a boss part for screwing various members, a through hole for electric wiring, and the like are provided. Therefore, detailed description will be omitted.

As shown in FIG. 2, the image reading unit 5 includes an image sensor unit 52, a roller unit 94, a guide shaft 62, and a belt driving mechanism 30. The image sensor unit 52 is configured by combining an image sensor 50 and a carriage 51. The image sensor 50 is a contact-type image sensor that irradiates a document as a read medium with light, photoelectrically converts reflected light from the document, and outputs an electrical signal.
It is called. The image sensor 50 has a casing 49 mounted on the carriage 51, and can reciprocate below the platen glasses 21 and 23 with the longitudinal direction of the casing 49 as the main scanning direction and the short direction as the sub-scanning direction. Arranged (see FIG. 4). The carriage 51 is fitted with a guide shaft 62 installed over the width direction of the lower frame 20 </ b> A, and the belt driving mechanism 30.
And is slid and moved on the guide shaft 62 (see FIG. 4).
When the carriage 51 is mounted so that the image sensor 50 is brought into close contact with the platen glasses 21 and 23 and moves on the guide shaft 62, the image sensor 50 is reciprocated in parallel with the platen glasses 21 and 23.

As shown in FIG. 3, the image sensor 50 is mounted on the carriage 51 so as to be supported on the upper side of the carriage 51, and the lower surface of the carriage 51 is fitted over the guide shaft 62 from above. A shaft receiving portion 54 is formed. The shaft receiving portion 54 and the guide shaft 62 are fitted to each other so that the carriage 51 is supported by the guide shaft 62 and is slidable in the axial direction of the guide shaft 62.

Further, a belt gripping portion 55 (see FIG. 3) projects downward from the side of the shaft receiving portion 54. The belt gripping portion 55 is for connecting the timing belt 61 and the carriage 51 by gripping the timing belt 61 of the belt driving mechanism 30.
As a result, the driving force is transmitted from the belt driving mechanism 30 to the carriage 51, and the carriage 51 reciprocates on the guide shaft 62. Since the belt drive mechanism 30 is irrelevant to the spirit of the present invention, the description thereof is omitted here.

Further, as shown in FIG. 5, spring receiving portions 56 are formed on the bottom portion 71 of the carriage 51 on which the image sensor 50 is mounted at two locations on the left and right sides of the carriage 51 in the main scanning direction. The coil spring 57 is positioned by the spring receiving portion 56 and is provided between the image sensor 50 and the carriage 51. Due to the urging force of the coil spring 57, the image sensor 50 mounted on the carriage 51 is in close contact with the lower surfaces of the platen glasses 21 and 23.

The roller unit 94 is provided on both ends of the image sensor 50. The roller unit 94 will be described in detail later. As described above, the image sensor 50 is
It moves along the platen glasses 21 and 23 as the carriage 51 moves while being pressed against the lower surfaces of the platen glasses 21 and 23. The roller unit 94 includes an image sensor 50.
It supports the smooth movement of Further, the roller unit 94 includes the image sensor 50.
It also serves as a spacer that keeps the distance between the platen glass 21 and 23 constant.

As described above, the image sensor unit 52 includes the image sensor 50 and the carriage 51.
Are combined. As shown in FIG. 4, the image sensor 50 has a rectangular parallelepiped housing 49 whose upper surface 63 is an elongated rectangle in plan view. On the upper surface 63 of the housing 49, a light guide body 64 that guides light of an LED (Light Emitting Diode: not shown) built in the housing 49 is continuously arranged in the longitudinal direction of the housing 49. . By this light guide 64, the light of the LED is emitted toward the platen glasses 21 and 23 arranged to face the upper surface 63 of the casing 49 of the image sensor 50. A plurality of condensing lenses 65 are arranged in a row in the longitudinal direction of the housing 49 on the upper surface 63 of the housing 49 so as to be parallel to the light guide 64. Further, in the housing 49, a plurality of photoelectric conversion elements (not shown) are arranged in the same direction as the condenser lens 65 immediately below the condenser lens 65. Accordingly, the light emitted from the LED is applied to the original (read medium) placed on the platen glass 21 or the original (read medium) moving on the platen glass 23, and the reflected light is reflected on the condenser lens 65. Thus, the light is condensed on the photoelectric conversion element. The photoelectric conversion element outputs an electrical signal corresponding to the intensity of the reflected light. In this way, the image sensor 50 outputs an image of a document (read medium) as an electrical signal.

A connector portion (not shown) is provided on the bottom surface of the casing 49 of the image sensor 50 and on one end side in the longitudinal direction of the casing 49. The connector part is LE of the image sensor 50.
D is electrically connected to the photoelectric conversion element, and is used to input / output signals and the like with the control unit. An electrical cable (not shown) is connected to the connector portion, and the image sensor 50 and the control unit of the image reading apparatus 1 are electrically connected by this electrical cable. The control unit of the image reading apparatus 1 includes, for example, a CPU for performing various calculations and an RO in which various control programs are stored.
M, a RAM for temporarily storing data, an ASIC for driving a drive circuit, various interfaces, and the like. The electric cable forms an electric signal path between the image sensor 50 and the control unit. However, since the connector portion is not related to the gist of the present invention, it will not be described in detail here.

The longitudinal direction of the casing 49 of the image sensor 50 is the main scanning direction in image reading. The length in the main scanning direction, that is, the length in the longitudinal direction of the housing 49 of the image sensor 50 is
The length corresponds to the maximum size of the read medium that can be read by the image sensor 50. In the present embodiment, the image sensor 50 has a length corresponding to a read medium of A4 size.

Hereinafter, the configuration of the roller unit holding portions 90A and 90B and the roller unit 94 of the image sensor 50 will be described in detail.

As shown in FIG. 5, the roller unit holding portion 90 </ b> A is provided at both ends of the casing 49 in the longitudinal direction.
, 90B are provided. The roller unit holding portions 90 </ b> A and 90 </ b> B are configured by stepped portions formed at corners in the longitudinal direction of the casing 49. Specifically, the stepped portion is formed in the housing 49.
Are formed by a vertical surface 150 orthogonal to the upper surface 63 and a mounting surface 151 which is continuous with the vertical surface 150 and orthogonal to the vertical surface 150. Accordingly, the vertical surface 150 is a surface extending downward from the upper surface 63 of the housing 49. The placement surface 151 is a surface that extends outward in the longitudinal direction from the lower end of the vertical surface 150 and is parallel to the upper surface 63.

The roller unit 94 is placed on a step formed by the vertical surface 150 and the placement surface 151. The placement surface 151 has a pair of positioning projections 105 (positioning members) for positioning and fixing the roller unit 94 and an adjustment sheet 110 described later. The pair of positioning projections 105 are fitted into a pair of positioning holes 106A and 106B of a roller unit 94 described later, whereby the roller unit 94 is positioned and fixed to the roller unit holding portions 90A and 90B.

Further, a roller unit holding portion 90 corresponding to the short direction of the casing 49 of the image sensor 50.
The dimension W1 of A and 90B is set to a predetermined dimension. The dimension W1 is variously set according to the specifications of the image sensor 50. The dimension W in the short direction of the casing 49 of the image sensor 50 is used.
It is set to be 2 or less.

Further, the roller unit holding portion 90 corresponding to the longitudinal direction of the casing 49 of the image sensor 50.
A dimension T1 of A and 90B is set to a predetermined dimension. The dimension T1 is variously set according to the specifications of the image sensor 50, and is set to be equal to or smaller than the dimension T2 of the mounting surface 151 corresponding to the longitudinal direction of the casing 49 of the image sensor 50.

Therefore, when the roller unit 94 is positioned and fixed to the roller unit holding portions 90A and 90B, the roller unit 94 is disposed within the projected area when the upper surface 63 of the casing 49 of the image sensor 50 is viewed in plan. The image sensor unit 52 itself can be downsized, and as a result, the image reading apparatus 1 can be downsized.

As shown in FIGS. 5 and 6, the roller unit 94 includes a frame 91 and a pair of rollers 92 and 93. The frame 91 is configured as a block that supports the rollers 92 and 93. The frame 91 includes a pair of side plates 95 and 96 having a dimension W1, a pair of connection plates 97A (dimension T1) for connecting them, a pair of connection plates 97B, and a bottom plate 107, which are made of, for example, synthetic resin. It is integrally formed. With this configuration, the roller 91 is formed with two roller accommodating portions 97 and 98. The rollers 92 and 93 are accommodated in the roller accommodating portions 97 and 98, respectively. The bottom plate 107 is provided with a pair of positioning holes 106A and 106B that can be fitted to the pair of positioning protrusions 105 disposed in the roller unit holding portions 90A and 90B of the image sensor 50 described above. Further, as shown in FIG. 6, the positioning holes 106B are located on the side plates 95, 96 more than the positioning holes 106A.
It is long in the direction along This is because the pair of positioning protrusions 105 on the mounting surface 151.
And dimensional tolerances are taken into account. Further, the side plates 95 and 96 are provided with bearing portions 100 and 101.
Is provided. The bearing portions 100 and 101 are formed by notched concave portions provided in the side plates 95 and 96, and rotatably support the support shafts 102 and 103 provided in the rollers 92 and 93.

The roller 92 has a disk shape and includes the support shaft 102. This support shaft 102 is
It is provided at the center of the roller 92 and extends in a direction parallel to the longitudinal direction of the casing 49 of the image sensor 50. Both end portions of the support shaft 102 are fitted and supported by the bearing portions 100 of the side plates 95 and 96, and the roller 92 is disposed in the roller accommodating portion 90 in a rotatable state. Since the roller 93 has the same configuration as the roller 92, the description thereof is omitted.

Moreover, the roller 92 and the roller 93 are arrange | positioned on the virtual straight line 104 (refer FIG. 7). The virtual straight line 104 is a straight line that is virtually set along a direction parallel to the short side direction of the casing 49 of the image sensor 50. That is, the pair of rollers 92 and 93 are arranged on a straight line and are not displaced in a direction parallel to the longitudinal direction of the casing 49 of the image sensor 50. However, even if the pair of rollers 92 and 93 are displaced in the longitudinal direction, when the roller unit 94 is positioned and fixed to the roller unit holding portions 90A and 90B, the upper surface 63 of the housing 49 of the image sensor 50 is flat. When viewed, the roller unit 94 only needs to be arranged within the projected area.

When the roller unit 94 is positioned and fixed to the roller unit holding portions 90 </ b> A and 90 </ b> B, an adjustment sheet 110 that is an adjustment member is provided between the placement surface 151 and the bottom plate 107. The adjustment sheet 110 is for adjusting the distance between the image sensor 50 and the platen glasses 21 and 23 in order to focus the image sensor 50 on the surface 28 of the platen glass 21. The adjustment sheet 110 is made of PET (Polyethylene Terephthalate).
e) a thin film piece made of a material such as, and the adjustment sheet 110 has a pair of insertion holes 111A,
111B is provided. As shown in FIG. 5, the insertion hole 111B has an insertion hole 111A.
It is formed longer in the direction along the short side direction of the casing 49 of the image sensor 50 than. This also takes into account the dimensional tolerance with the pair of positioning protrusions 105 on the mounting surface 151.

The outline of the procedure for positioning and fixing the roller unit 94 to the housing 49 of the image sensor 50 will be described below with reference to FIGS. 5 and 6.

First, a pair of insertion holes 111A and 111B provided in the adjustment sheet 110 are inserted and positioned through a pair of positioning projections 105 provided in the roller unit holding portion 90A. At this time, in order to adjust the distance between the image sensor 50 and the platen glass 21, a plurality of adjustment sheets 110 may be stacked and may not be disposed depending on circumstances.
Similarly, the adjustment sheet 110 is appropriately positioned in the roller unit holding portion 90B.

Next, in a state where the pair of rollers 92 and 93 are supported by the frame 91, the positioning protrusion 105 is fitted into the pair of positioning holes 106A and 106B of the frame 91 as described above. Thereby, the roller unit 94 is positioned and fixed to the housing 49 as shown in FIG. In this state, as shown in FIG. 3, the rollers 92 and 93 of the roller unit 94.
Is in contact with the back surface 27 of the platen glass 21. The rollers 92 and 93 roll around the back surface 27 of the platen glass 21 by rotating around the support shafts 92 and 93.

In the image reading apparatus 1 according to the present embodiment, as shown in FIG. 3, the surface 28 of the platen glass 21 constitutes a document placement surface on which a document is placed. The document is placed face down on the surface 28 of the platen glass 21. Then, as shown, the carriage 50 of the image reading unit 5 moves in a direction perpendicular to the paper surface of FIG. 3, whereby the document is scanned and an image on the document is read.

A roller unit 94 is provided at the longitudinal end of the carriage 50 (see FIG. 7).
The rollers 92 and 93 provided in the roller unit 94 are in contact with the back surface 27 of the platen glass 21 in a state where the rollers 92 and 93 are juxtaposed in the lateral direction of the casing 49 of the image sensor 50 (
(See FIG. 3). Therefore, the carriage 50 moves with its end portions supported by the rollers 92 and 93, and thus the carriage 50 moves smoothly without being inclined with respect to the back surface 27 of the platen glass 21. The roller unit 94 is housed in roller unit holding portions 90A and 90B provided in the casing 49 of the carriage 50, and corresponds to the short direction of the casing 49 of the image sensor 50 as described above. Roller unit holder 9
The dimension W1 of 0A and 90B is set to be equal to or smaller than the dimension W2 in the short direction of the casing 49 of the image sensor 50. Further, the dimension T1 of the roller unit holding portions 90A and 90B corresponding to the longitudinal direction of the casing 49 of the image sensor 50 is equal to or smaller than the dimension T2 of the mounting surface 151 corresponding to the longitudinal direction of the casing 49 of the image sensor 50. Is set to Therefore, when the upper surface 63 of the housing 49 of the image sensor 50 is viewed in plan, the roller unit 94 is disposed within the projected area. Therefore, in the design of the carriage 50, the dimensions in the longitudinal direction and the lateral direction can be suppressed. As a result, the image sensor unit 52 itself can be downsized, and as a result, the image reading apparatus 1 can be downsized.

Further, since the roller unit 94 includes the rollers 92 and 93, the image sensor 50 is prevented from being tilted when moving, and the image sensor 50 and the platen glass 21 are prevented from moving.
The distance from the back surface 27 of the lens is kept constant. As a result, good image reading is realized.

In particular, in the present embodiment, the pair of rollers 92 and 93 are arranged on the virtual straight line 104. That is, the rollers 92 and 93 are arranged side by side in the short direction. Therefore, there is an advantage that when the carriage 50 moves, the pair of rollers 92 and 93 is reliably prevented from being inclined relative to the carriage 50. Also, a pair of rollers 92,
There is an advantage that 93 is reliably tilted relative to the back surface 27 of the platen glass 21 and that the carriage 50 is relatively tilted relative to the back surface 27 of the platen glass 21.

Further, in the present embodiment, the roller unit 94 is housed in roller unit holding portions 90A and 90B composed of the above stepped portions (see FIG. 5). The roller unit 94 is not placed on the upper surface 63 of the housing 49 as in the conventional case, but is placed on the placement surface 151 that constitutes the stepped portion so as to be dropped downward from the upper surface 63. Placed. Therefore,
The roller unit 94 is disposed in the housing 49 such that the tops of the rollers 92 and 93 protrude slightly upward from the upper surface 63 of the housing 49. Accordingly, the image sensor 50 is positioned in a state of being very close to the back surface 27 of the platen glass 21, and as a result, the image sensor 50 can accurately read an image from the original.

In this embodiment, the adjustment sheet 110 is positioned by inserting a pair of insertion holes 111A and 111B provided in the adjustment sheet 110 into a pair of positioning protrusions 105 provided in the roller unit holding portion 90A. Therefore, the assemblability is improved. That is, the assemblability is improved as compared to the case where the bottom plate 107 of the roller unit 94 is provided with a projection such as the positioning projection 105 and the mounting surface 151 is provided with positioning holes such as the positioning holes 106A and 106B. It is. In the case where the projection is provided on the bottom plate 107 of the roller unit 94 and the positioning hole 151 is provided on the mounting surface 151, the adjustment sheet 110 is provided on the projection provided on the bottom plate 107 with the roller unit 94 upside down. A pair of insertion holes 111A,
After 111B is inserted, the protrusion of the roller unit 94 must be fitted into the positioning hole provided in the mounting surface 151 with the roller unit 94 upside down. However, when the roller unit 94 is placed on the placement surface 151, there is a high possibility that the adjustment sheet 110 falls from the bottom plate 107 of the roller unit 94. Further, the positioning hole of the mounting surface 151 and the adjustment sheet 11
After the adjustment sheet 110 is placed on the placement surface 151 so that the zero insertion holes 111A and 111B communicate with each other, the protrusion of the bottom plate 107 of the roller unit 94 is inserted into the positioning hole of the placement surface 151. This is because the work becomes very detailed and the assemblability deteriorates. Next, the configuration of the image sensor unit 52 will be described in detail.

At both ends of the casing 49 of the image sensor 50, as shown in FIGS.
A and 68B are provided. The shaft portions 68A and 68B position the image sensor 50 in the sub-scanning direction with respect to the carriage 51.

Each of the shaft portions 68A and 68B is formed by forming a pair of plane portions 70 substantially parallel to a cylindrical shaft having a diameter L1 at an equal distance from the axis. This set of plane portions is a distance L2
It is provided only apart. The distance L2 is set smaller than the distance L1. Such an axis is referred to herein as an oval axis.
Of the pair of shaft portions 68A and 68B, a contact portion 67 is formed at the starting end portion of one shaft portion 68A, and a protruding portion 66 is formed at the tip portion.

As shown in FIGS. 4 and 5, the carriage 51 has a container shape with the upper surface opened, on which the image sensor 50 is mounted. As shown in FIG.
It has a bottom portion 71 and walls 72 erected upward from both ends of the bottom portion 71 on the sub-scanning direction side.
A pair of bearing portions 73A and 73B are formed at both ends of the bottom portion 71 on the main scanning direction side. The pair of bearing portions 73A and 73B are disposed at positions that can be engaged with the pair of shaft portions 68A and 68B, respectively. The pair of bearing portions 73A and 73B project upward from the bottom 71, and a U-shaped groove 75 having a groove width L1 ′ (in this case, slightly L1 ′> L1) is formed in the projecting piece 74. It becomes. A pair of retaining portions 75a are formed at the open end of the groove 75 with a distance L2 ′ (in this case, slightly L2 ′> L2) (L1 ′> L2 ′; see FIG. 9).
.

Hereinafter, a procedure for forming the image sensor unit 52 by the image sensor 50 and the carriage 51 will be described with reference to FIGS.

First, the upper surface 63 of the image sensor 50 and the bottom portion 71 of the carriage 51 are arranged so as to be substantially orthogonal so that the left and right of the image sensor 50 and the carriage 51 are aligned in the main scanning direction. The portion 70 is fitted into the groove 75 in a direction opposite to the retaining portion 75 a provided in the groove 75.

Here, the image sensor 50 is rotated around the shaft portions 68A and 68B so that the lower surface (not shown) of the image sensor 50 with respect to the upper surface 63 and the bottom portion 71 of the carriage 51 are opposed to each other. Then, the lower surface (not shown) of the image sensor 50 with respect to the upper surface 63 is positioned by the spring receiving portion 56 provided on the bottom portion 71 of the carriage 51.
7 is contacted. By this coil spring 57, the image sensor 50 and the carriage 51 are urged away from each other.

In this state, the image sensor 50 is positioned with respect to the carriage 51 in the sub-scanning direction. That is, the image sensor 50 is positioned with respect to the carriage 51 in the sub-scanning direction by appropriately designing the width L1 ′ in the short direction of the groove 75 and the diameter L1 of the shaft portions 68A and 68B.

The positioning of the image sensor 50 with respect to the carriage 51 in the main scanning direction is as follows.
The projecting piece 74 of the bearing 73 and the contact part 67 and the projecting part 66 formed on the shaft part 68A.
Is done through collaboration. That is, by appropriately designing the thickness of the projecting piece 74 and the distance from the contact portion 67 to the projecting portion 66, the image sensor 50 can move the carriage 51.
Is positioned in the main scanning direction.

Further, the groove 75 formed in the bearing portion 73 of the carriage 51 has a groove width in the sub-scanning direction,
When the image sensor unit is disposed in the image reading apparatus 1, the platen glass 21,
It is a U-shape opened toward 23. Therefore, the shaft portions 68A and 68B can move along the groove 75, that is, the image sensor 50 can come in contact with and separate from the carriage 51 in the direction of the platen glasses 21 and 23 according to the expansion and contraction of the coil spring 57. It is.

In this manner, the image sensor 50 is supported so as to be rotatable and capable of moving toward and away from the carriage 51, and is positioned in the main scanning direction and the sub-scanning direction.

Further, the diameter L1 of the cylindrical shaft, the separation distance L2 ′ between the pair of retaining portions 75a, and the shaft portion 6
By appropriately designing the separation distance L2 of the pair of flat surface portions 70 provided in 8A and 68B, the shaft portion 68 can be prevented from being accidentally detached from the groove 75.

As described above, in the present embodiment, the shaft portions 68A and 68B are provided on the housing 49 of the image sensor 50.
Projecting from both end surfaces 69 in the longitudinal direction of the first shaft portion 68A of the pair of shaft portions 68A, 68B.
In A, a positioning member including a contact portion 67 and a protruding portion 66 is formed. The bearing portions 73 are formed at both ends of the carriage 51 on the main scanning direction side, and one bearing portion 73 of the pair of bearing portions 73 includes a contact portion 67 and a protruding portion 66 provided on the shaft portion 68A. In cooperation, positioning of the casing 49 in the longitudinal direction with respect to the carriage 51 is performed. Therefore, it is possible to reduce the size of the image sensor unit 52 in the sub-scanning direction compared to a configuration in which the length of the image sensor unit in the short direction includes the length of the positioning member in the sub-scanning direction. is there.

In the present embodiment, the abutting portion 67 and the protruding portion 66 are formed integrally with the shaft portion 68 </ b> A, but at least one of the abutting portion 67 and the protruding portion 66 is attached to the housing 49 of the image sensor 50.
It may be configured as a separate member and fixed to the shaft portion 68A later.

Of the pair of shaft portions 68A and 68B, one shaft portion 68A has a contact portion 67 and a protruding portion 6.
6 is formed, the degree of freedom in design is improved as compared with the case where members for determining the main scanning direction are formed on both of the shaft portions 68A and 68B. That is,
When members for determining the main scanning direction are provided on both of the shaft portions 68A and 68B, the dimensional tolerance of the image sensor 50 itself and the dimensional tolerance of the carriage 51 must be matched with high accuracy, and the yield of parts is increased. This is because there is a risk of lowering.

Further, the groove 75 formed in the bearing portion 73 of the carriage 51 has a groove width in the sub-scanning direction, and has a U shape opened toward the platen glass 21 (see FIG. 5B). Is provided. Therefore, the shaft portion 68 of the image sensor 50 can move along the groove 75, that is, the image sensor 50 can move in accordance with the expansion and contraction of the coil spring 57 provided between the image sensor 50 and the carriage 51. It is possible to contact and separate. Therefore, even when the distance between the back surface of the platen glass 21 and the carriage 51 changes depending on various conditions, the distance between the upper surface 63 of the image sensor 50 and the back surface of the platen glass 21 can be kept constant. 50 can read an image from a document satisfactorily.

Next, a second embodiment according to the present invention will be described with reference to FIGS. In addition, since the same number is provided to the location similar to 1st Embodiment, the location is not explained in full detail.

The image sensor 350 according to the second embodiment is different from the image sensor 50 according to the first embodiment only in the structure of the roller unit holding portions 190A and 190B. The roller unit 194 of the second embodiment is different from the roller unit 94 of the first embodiment only in the structure of the bottom plate 207 and the dimensions of the frame 191.

  Hereinafter, the structures of the image sensor 350 and the roller unit 194 will be described.

The image sensor 350 has a rectangular parallelepiped housing 149 whose upper surface 163 is an elongated rectangle in plan view. The upper surface 163 of the housing 149 has an LED (Lig built in the housing 149).
A light guide body 64 that guides light of ht Emitting Diode (not shown) is continuously arranged in the longitudinal direction of the housing 149. By this light guide 64, the light of the LED is emitted toward the platen glasses 21 and 23 that are disposed to face the upper surface 163 of the housing 149 of the image sensor 350. A plurality of condensing lenses 65 are arranged in a line in the longitudinal direction of the housing 149 on the upper surface 163 of the housing 149 so as to be parallel to the light guide 64. Since the internal structure of the image sensor 350, the configuration of signal output, and the like are the same as those of the image sensor 50, they will not be described in detail here.

Hereinafter, the configuration of the roller unit holding portions 190A and 190B and the roller unit 194 of the image sensor 350 will be described in detail.

As shown in FIG. 10, roller unit holding portions 190 </ b> A and 190 </ b> B are provided at both ends in the longitudinal direction of the casing 49 of the image sensor 350. This roller unit holding part 1
90 </ b> A and 190 </ b> B are constituted by concave portions formed at corners in the longitudinal direction of the housing 149. Specifically, the concave portion has a vertical surface 250A orthogonal to the upper surface 163 of the housing 149,
250B and a mounting surface 251 that is continuous with the vertical surface 250A and orthogonal to the vertical surfaces 250A and 250B.
And is formed by. The positioning member referred to in the claims includes vertical surfaces 250 </ b> A and 250 </ b> B and a mounting surface 251. Accordingly, the vertical surfaces 250A and 250B are formed on the casing 14.
9 is a surface extending downward from the upper surface 163 of the substrate. The placement surface 251 is a surface parallel to the upper surface 163.

The roller unit 194 includes the vertical surfaces 250A and 250B and the mounting surface 251.
And placed in a recess formed by The dimensions of the roller unit 194 may be set as appropriate so as to be accommodated in the recess. The mounting surface 251 is provided with the roller unit 194.
Has a pair of positioning holes 205A and 205B for positioning and fixing. The pair of positioning holes 205A and 205B are fitted with a pair of positioning projections 206 of a roller unit 194, which will be described later, so that the roller unit 194 is in contact with the roller unit holding portion 1.
Positioned and fixed to 90A and 190B.

Therefore, when the roller unit 194 is positioned and fixed to the roller unit holding portions 190A and 190B, the roller unit 194 is disposed within the projected area when the upper surface 163 of the housing 149 of the image sensor 350 is viewed in plan view. The image sensor unit itself configured with a carriage (not shown) can be downsized, and as a result, the image reading apparatus 1 can be downsized.

As shown in FIG. 10, the roller unit 194 includes a frame 191 and a pair of rollers 192 and 193. The frame 191 is configured as a block that supports the rollers 192 and 193. As shown in FIG. 11, the frame 191 includes a bottom plate 207, and is formed of, for example, a synthetic resin. The bottom plate 207 is provided with a pair of positioning protrusions 206 that can be fitted into the pair of positioning holes 205A and 205B disposed in the roller unit holding portions 190A and 190B of the image sensor 350 described above. As shown in FIG. 10, the positioning hole 205B is formed longer in the direction along the short direction of the housing 149 than the positioning hole 205A. This is the roller unit 194
Dimensional tolerance between the pair of positioning protrusions 206 protruding from the bottom plate 207 is taken into consideration.

When the roller unit 194 is positioned and fixed to the roller unit holding portions 190A and 190B, the adjustment sheet 1 is placed between the placement surface 251 and the bottom plate 207 as in the first embodiment.
10 is provided. The configuration of the adjustment sheet 110 will not be described in detail.

Hereinafter, referring to FIG. 10 and FIG. 11, the roller unit 194 is connected to the image sensor 35.
An outline of the procedure for positioning and fixing to the zero casing 149 will be described.

First, the adjustment sheet 110 is in the direction in which the pair of insertion holes 111A and 111B provided in the adjustment sheet 110 face the pair of positioning holes 205A and 205B.
It is inserted and positioned in a recess provided in 90A. At this time, due to the length of the hole,
The insertion hole 111A and the positioning hole 205A are arranged to face each other, and the insertion hole 111B and the positioning hole 2 are disposed.
It is desirable that 05B is disposed to face the surface. In order to adjust the distance between the image sensor 350 and the platen glasses 21 and 23, a plurality of adjustment sheets 110 may be arranged in a stacked manner, or may not be arranged depending on circumstances. Also, the roller unit holding part 190B
Similarly, the adjustment sheet 110 is appropriately positioned.

Next, with the pair of rollers 192 and 193 supported by the frame 191, as described above, the pair of positioning protrusions 206 of the frame 191 are fitted into the positioning holes 205A and 205B. As a result, the roller unit 194 is positioned and fixed to the housing 149.
However, even if the pair of positioning protrusions 206 and the positioning holes 205A and 205B of the frame 191 are eliminated by appropriate design, the roller unit 194 can be positioned and fixed by the recess. Accordingly, the positioning protrusion 206 and the positioning holes 205A and 205B are optional constituent requirements.

Also in the second embodiment, the adjustment sheet 110 is provided with the roller unit holding portion 190A.
, 190B is inserted only into the recess formed in 190B, and assemblability can be improved as in the first embodiment.

In the first embodiment and the second embodiment, the roller unit can also be positioned by the positioning member that positions the adjustment sheet (adjustment member). Therefore, another positioning member for the roller unit is formed. Space is not required and the image sensor can be miniaturized.

1 is a perspective view showing an external configuration of an image reading apparatus according to an embodiment of the present invention. It is a top view which shows the internal structure of a reading mounting base. It is a longitudinal cross-sectional view which shows the main structures of a reading mounting base. It is a perspective view which shows the structure of the image sensor unit which concerns on 1st Embodiment. FIG. 5 is an exploded view of essential parts of the image sensor unit of FIG. It is a principal part disassembled enlarged view of a roller unit. It is a principal part enlarged view of an image sensor unit. It is an upper surface enlarged view of an image sensor unit. It is a side enlarged view of an image sensor unit. Exploded perspective view of an image sensor according to the second embodiment The perspective view which looked at the frame of the roller unit in 2nd Embodiment from the baseplate side It is a principal part perspective view of the conventional image sensor unit. It is a principal part disassembled perspective view of the conventional image sensor unit.

DESCRIPTION OF SYMBOLS 1 Image reading apparatus 2 Reading mounting base 3 Automatic document conveying apparatus 4 Document pressing cover 5 Image reading unit 6A Roller unit 6B Roller unit 7A Frame 7B Frame 8 Roller 9 Roller 10 Engaging pin 11 Arrow 12 Image sensor 13 Upper surface 14 Image sensor 15A Roller unit 15B Roller unit 17 Roller 18 Roller 19 Back surface 20 Document placement table housing 20A Lower frame body 20B Upper cover 21 Platen glass 22 Operation panel 23 Platen glass 24 Base portion 25 Side wall 26 Partition plate 27 Back surface 28 Front surface 30 Belt drive mechanism 49 Housing 50 Image sensor 51 Carriage 52 Image sensor unit 54 Shaft receiving portion 56 Spring receiving portion 57 Coil spring 61 Timing belt 62 Guide shaft 63 Top Surface 64 Light guide 65 Condenser lens 66 Projection part 67 Contact part 68A Shaft part 68B Shaft part 70 Flat part 71 Bottom part 72 Wall 73A Bearing part 73B Bearing part 74 Projection piece 75 Groove 90A Roller unit holding part 90B Roller unit holding part 91 Frame 92 Roller 93 Roller 94 Roller unit 95 Side plate 96 Side plate 97 Roller receiving portion 98 Roller receiving portion 99 Engaging pin 100 Bearing portion 101 Bearing portion 102 Support shaft 103 Support shaft 104 Virtual straight line 105 Positioning hole 106 Engaging hole 107 Bottom plate 110 Adjustment sheet 111A Mounting portion 111B Mounting portion 149 Housing 150 Vertical surface 151 Mounting surface 163 Top surface 191 Frame 192 Roller 193 Roller 194 Roller unit 205A Positioning hole 205B Positioning hole 206 Positioning protrusion 207 Bottom plate 250A Vertical surface 250B Vertical surface 251 Mounting surface 350 Image sensor

Claims (4)

An original platen glass on which an original can be placed stationary, an image sensor unit capable of reciprocating along the lower surface of the original table glass, and rolling while being in close contact with the lower surface of the original table glass disposed in the image sensor unit. An image sensor for use in an image reading device comprising:
A housing having a longitudinal direction;
A roller unit holding portion that is provided at both ends in the longitudinal direction of the housing and can hold a roller unit that rotatably supports the roller; and
A positioning member of an adjusting member capable of adjusting the distance between the image sensor and the original table glass by being disposed between the casing and the roller unit is provided in the roller unit holding portion ,
The roller unit holding portions are stepped portions provided at both ends in the longitudinal direction of the casing.
The positioning member of the adjustment member is a protrusion protruding from the mounting surface constituting the step portion.
The adjustment member is positioned by inserting the protrusion into the insertion hole provided in the adjustment member.
-Decided fit is an image sensor, wherein Rukoto. By inserting the protrusion into the positioning hole provided in the bottom surface of the roller unit
The roller unit is positioned with respect to the housing.
Image sensor. A platen glass on which a document can be placed stationary, and reciprocating along the bottom surface of the platen glass
An image sensor unit, and the platen glass disposed on the image sensor unit.
An image sensor for use in an image reading apparatus comprising: a roller that rolls in close contact with the lower surface.
S
  A housing having a longitudinal direction;
  Roller units that are provided at both ends of the casing in the longitudinal direction and support the rollers rotatably.
A roller unit holding part capable of holding the
  The image sensor is disposed between the housing and the roller unit.
A positioning member of an adjustment member capable of adjusting the distance from the platen glass is a roller unit holding member.
It is provided in the holding part,
The roller unit holding portion is a recess provided at both ends in the longitudinal direction of the casing.
The positioning member of the adjustment member is a vertical surface and a mounting surface that constitute the recess, and the recess
The image sensor is characterized in that the adjustment member is positioned by being inserted into a portion. Positioning hole in which the protrusion protruding from the bottom surface of the roller unit is provided on the mounting surface
The roller unit is positioned with respect to the housing by being inserted into the housing.
The image sensor according to claim 3.

Images