JP2002199159A - Image sensor unit and image reader provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image sensor unit and a picture reader provided with it, which obtain a satisfactory image and are made compact effectively. SOLUTION: The image sensor unit is provided with a light source 6 which has a read face of a document PP irradiated with light, a photodetector 3 which receives the reflected light from the document PP, an image-forming device 7 which forms an image of reflected light on the photodetector 3, and a frame 1 to which these members are attached directly or indirectly. Light is made incident on and reflected from the document PP through a transparent member 5 which can be brought into contact with the read face of the document PP. A positioning means 9, which positions and supports the image-forming device 7 and the photodetector 3, is provided separately from the frame 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor for reading reflected light from a document surface by a sensor and an image reading apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, a sensor array for performing photoelectric conversion, an imaging element for forming an image of light from a document on the sensor array, a transparent member for defining a reading surface of the document, and a light source for illuminating the document. There is known a contact type image sensor having a support for supporting the image sensor.

FIG. 15 is a schematic perspective view showing the appearance of a conventional contact image sensor. In the drawing, reference numeral 1 denotes a frame as a support, and 5 denotes a cover glass as a transparent member which can contact a document and defines a reading surface thereof. A large number of optical sensors (pixels) are arranged in the longitudinal direction (main scanning direction) DM of the support 1, and the short direction DS is the sub-scanning direction.

FIG. 16 shows a cross section taken along line FF 'of FIG. An imaging element 7 is provided in the first space 1A of the frame 1.
Is arranged. The imaging element 7 includes a lens 71, and side plates 72 and 73 for enabling the lenses 71 to be formed in one or more rows of lens arrays. The light source 6 is arranged in the second space 1B. The light source 6 guides light from one or more LED light sources 63 in the main scanning direction DM, and illuminates the document PP.
To prevent light from leaking from the light guide plate 61 and
And a housing 62 which is a frame member having a function of efficiently illuminating the document PP by determining the position of the document PP. The first space 1A and the second space 1B communicate with each other.

[0005] The sensor array 3 is provided on an electric circuit board 4 and is arranged between the frame 1 and the frame 2 as a second support toward the third space 1C.

[0006] The method of assembling such an image sensor is performed as follows. That is, the light source 6 is fixed to the mounting surface 1D of the frame 1 with an adhesive or a screw, and the imaging element 7 is inserted into the first space 1A and fixed to the mounting surface 1E of the frame 1 with an adhesive or a screw. Then, the electric circuit board 4 provided with the sensor array 3 is fixed to the frame 1 by the frame 2. Alternatively, the electric circuit board 4 on which the sensor array 3 is provided is attached to the frame 1 with an adhesive or a screw.
It is to fix to.

[0007]

The greatest advantage of this type of close contact type image sensor is that it can be formed into a compact product. However, in the conventional example described above, in order to further develop and realize compactness in the future,
There are the following problems.

That is, as the size of the imaging element 7 becomes smaller, the lens diameter of the imaging element 7 becomes smaller,
Since the effective aperture area from the optical axis, which is the lens center axis, becomes narrow, the accuracy of alignment with the light receiving section of the sensor array 3 becomes important. In the conventional example, the frame 1 has a support function for positioning by incorporating all the functional components of the imaging element 7, the electric circuit board 4, the light source 6, and the transparent member 5. Since the dimensional accuracy of the frame components and the alignment accuracy of the assembly were limited, the optical axis of the imaging element 7 and the position of the light receiving portion of the sensor array 3 were shifted, and the light information from the document PP to the light receiving sensor was reduced. There is a problem that the image is deteriorated.

Further, as the size of the imaging element 7 is reduced in size, the focal length of the imaging element 7 is reduced, and the distance from the surface of the lens array 71 on the side facing the original to the original reading position is extremely large. Be shorter. As a result, the transparent member 5 and the lens array 71 come into contact with each other, damaging the transparent member 5 or the lens array 71, and causing a problem of deteriorating an image.

The present invention has been made in view of the above circumstances, and has as its object to provide an image sensor unit capable of obtaining a good image and effectively realizing a compact size, and an image reading apparatus having the same.

[0011]

An image sensor unit according to the present invention comprises: a light source for irradiating light to a reading surface of a document;
A light receiving element for receiving the reflected light from the document, an imaging element for forming an image of the reflected light on the light receiving element, and a frame for directly or indirectly attaching these members to the reading surface of the document An image sensor unit for allowing light to enter and reflect the document through a contactable transparent member, wherein a positioning member for positioning and supporting the imaging element and the light receiving element relatively is provided separately from the frame. The positioning support member protrudes from the image forming element toward the document, and comes into contact with the transparent member.

Further, in the image sensor unit according to the present invention, the positioning means is integrally formed with the imaging element.

Further, in the image sensor unit according to the present invention, the transparent member is attached to a predetermined portion of the frame.

Further, in the image sensor unit according to the present invention, the transparent member is disposed separately from the frame.

Further, the image reading apparatus according to the present invention has a moving mechanism for performing a predetermined relative movement between any one of the image sensor units and the document to be read. The original image is scanned by the relative movement of the original.

According to the present invention, positioning means for positioning and supporting the image forming element and the sensor array is provided separately from the frame (support), that is, the alignment accuracy between the optical axis of the image forming element and the light receiving section of the sensor array. Provide a dedicated alignment support with emphasis on. As a result, it is possible to effectively prevent the optical axis of the imaging element from being displaced from the light receiving portion of the sensor array, thereby reducing the light information from the document to the light receiving sensor and deteriorating the image.

Further, there is provided means for projecting beyond the surface of the lens array to the side of the positioning means facing the document and abutting on the transparent member. Thus, even if the focal length of the image forming element is shortened and the distance from the surface of the lens array facing the original to the original reading position is extremely short, the positioning means is provided before the lens array with respect to the transparent member. The contact means contacts. This effectively prevents the transparent member or the lens array from being damaged and deteriorating the image.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an image sensor according to the present invention and an information processing apparatus having the same will be described below in detail with reference to the drawings. Note that the same members as those in the conventional example are denoted by the same reference numerals and will be described.

FIGS. 1 to 4 show the features of the present invention best. FIG. 1 is a schematic perspective view of the transparent member from the document reading surface. FIG. 2 is a cross-sectional view taken along line GG ′ of FIG. FIG. 3 and FIG. 4 are views showing a state of a module positioned and supported by a dedicated positioning means for positioning an imaging element and a sensor array provided on an electric circuit board. FIG. 3 is a schematic perspective view of the imaging element from the document reading surface. FIG. 4 shows HH 'of FIG.
It is sectional drawing by a line.

In FIG. 4, the imaging element 7 is sandwiched between positioning supports 9 and the sensor array 3 is mounted on the electric circuit board 4 using the mounting reference holes 41 of the electric circuit board 4 as mounting positioning references. . The electric circuit board 4 is positioned and supported on the positioning support 9 with reference to the mounting reference hole 41. The mounting reference holes 41 are provided at two or more locations in the DM direction, and highly accurate positioning is performed.

In FIG. 2, a module in which an image forming element 7 and a sensor array 3 provided on an electric circuit board 4 are positioned and supported by positioning means 9 (FIGS. 3 and 4).
Are sandwiched between supports (or frames) 1.
Further, there is provided a contact means 91 for contacting the transparent member 5 positioned and supported by the support 1.

The contact means 91 is provided on the side of the positioning support 9 facing the document PP, and is formed in a shape projecting from the surface of the lens array 71. At this time, the thickness of the contacting means 91 provided on the positioning support 9 and protruding from the imaging element 7 is determined by the fact that the surface of the transparent member 5 capable of contacting the read original PP is the focal length at which the imaging element 7 can form an image. It is set so that the position is determined at the position TC and the position within the depth of field L.

With such a configuration, the imaging element 7
And the mounting position of the sensor array 3 are determined by the component accuracy of the positioning support 9 and the component accuracy of the electric circuit board 4. For this reason, the displacement between the optical axis of the imaging element 7 and the light receiving portion of the sensor array 3 due to work variation or the like is improved. Then, appropriate and effective optical information is sent from the document PP to the light receiving sensor, and a good image without image deterioration or the like can be obtained.

Further, since the focal length TC of the image forming element 7 is shortened, the distance from the surface of the lens array 71 on the side facing the document PP to the document reading position becomes extremely short. Also in this case, the abutting means 91 provided on the positioning support 9 abuts against the transparent member 5 before the ins array 71. This prevents the transparent member 5 or the lens array 71 on the effective optical path for image reading from being damaged, and in this respect, it is possible to obtain a good image without image deterioration or the like.

Next, a second embodiment of the present invention will be described. 5 to 8 are drawings showing the features of the present invention best. FIG. 5 is a schematic perspective view of the transparent member 5 from the document reading surface. FIG. 6 is a sectional view taken along line II ′ of FIG. FIGS. 7 and 8 are views showing the state of the module positioned and supported by the dedicated positioning means for positioning the imaging element and the sensor array provided on the electric circuit board. FIG. 7 is a schematic perspective view of the imaging element from the document reading surface. FIG. 8 is a sectional view taken along the line JJ ′ of FIG.

In FIG. 8, the imaging element 7 is integrally formed of a lens array 71 and side plates 72 and 73 having the function of the positioning support 9. Sensor array 3
Are mounted on the electric circuit board 4 using the mounting reference hole 41 of the electric circuit board 4 as a positioning reference. Electric circuit board 4
Are positioned and supported by the imaging element 7 having the function of the positioning support 9 based on the mounting reference hole 41.

Further, in FIG. 6, there is provided a contact means 7a for contacting the transparent member 5 positioned and supported by the support 1. The contacting means 7 a has the function of a positioning support 9, is provided on the side of the image forming element 7 facing the document PP, and is formed so as to protrude from the surface of the lens array 71. At this time, the thickness of the abutting means 7a provided on the imaging element 7 protruding from the imaging element 7 is determined by the reading original P of the transparent member 5.
The surface that can contact P is set so as to be determined at a focal distance position TC where the imaging element 7 can be imaged and a position within the depth of field L.

With this configuration, the imaging element 7
And the mounting position of the sensor array 3 are determined by the component accuracy of the imaging element 7 having the function of the positioning support 9 and the component accuracy of the electric circuit board 4. For this reason, deviation between the optical axis of the imaging element 7 and the light receiving section of the sensor array 3 due to work variation is improved. Then, appropriate and effective optical information is sent from the document PP to the light receiving sensor, and a good image without image deterioration or the like can be obtained.

Further, since the focal length TC of the imaging element 7 is shortened, the distance from the surface of the lens array 71 facing the original PP to the original reading position becomes extremely short. Also in this case, the abutting means 7a provided on the side plates 72 and 73 provided with the function of the positioning support 9 comes into contact with the transparent member 5 before the ins array 71. This prevents the transparent member 5 or the lens array 71 on the effective optical path for image reading from being damaged, and in this respect, it is possible to obtain a good image without image deterioration or the like.

Next, a third embodiment of the present invention will be described. 9 to 12 are drawings showing the features of the present invention best. FIG. 9 is a schematic perspective view of the transparent member 5 from the document reading surface. FIG. 10 is a sectional view taken along the line KK ′ in FIG. FIG. 11 and FIG. 12 are views showing the state of the module positioned and supported by the dedicated positioning means for positioning the imaging element and the sensor array provided on the electric circuit board. FIG. 11 is a schematic perspective view of the imaging element from the document reading surface. FIG. 12 is a cross-sectional view of FIG.
It is sectional drawing by a line.

In FIG. 12, the imaging element 7 is sandwiched between the positioning supports 9, and the sensor array 3 is mounted on the electric circuit board 4 using the mounting reference holes 41 of the electric circuit board 4 as mounting positioning references. . The electric circuit board 4 is positioned and supported on the positioning support 9 with reference to the mounting reference hole 41. The mounting reference holes 41 are provided at two or more locations in the DM direction, and highly accurate positioning is performed.

In FIG. 10, the module (FIGS. 11 and 12) in which the imaging element 7 and the sensor array 3 provided on the electric circuit board 4 are positioned and supported by the positioning support 9 is sandwiched by the support 1. Have been. Further, in this example, there is provided a contact means 91 for contacting the transparent member 5 attached to the flatbed scanner.

The contact means 91 is provided on the side of the positioning support 9 facing the document PP, and is formed in a shape projecting from the surface of the lens array 71. At this time, the thickness of the contacting means 91 provided on the positioning support 9 and protruding from the imaging element 7 is determined by the fact that the surface of the transparent member 5 capable of contacting the read original PP is the focal length at which the imaging element 7 can form an image. It is set so that the position is determined at the position TC and the position within the depth of field L. Further, the abutting means 91 is provided for the original P along the DM direction.
It is located outside the valid reading area of P.

With such a configuration, the imaging element 7
And the mounting position of the sensor array 3 are determined by the component accuracy of the imaging element 7 having the function of the positioning support 9 and the component accuracy of the electric circuit board 4. For this reason, deviation between the optical axis of the imaging element 7 and the light receiving section of the sensor array 3 due to work variation is improved. Then, appropriate and effective optical information is sent from the document PP to the light receiving sensor, and a good image without image deterioration or the like can be obtained.

Further, since the focal length TC of the image forming element 7 is shortened, the distance from the surface of the lens array 71 on the side facing the document PP to the document reading position becomes extremely short. Also in this case, the abutting means 91 provided on the positioning support 9 abuts against the transparent member 5 before the ins array 71. This prevents the transparent member 5 or the lens array 71 on the effective optical path for image reading from being damaged, and in this respect, it is possible to obtain a good image without image deterioration or the like.

FIG. 13 shows an example of a facsimile having a communication function as an image information processing apparatus constituted by using the contact type image sensor unit 100 according to the present embodiment. Here, reference numeral 102 denotes a feeding roller as a feeding unit for feeding the document PP toward the reading position, and reference numeral 104 denotes a separating piece for reliably separating and feeding the document PP one by one. Reference numeral 106 denotes a platen roller that is provided at a reading position with respect to the sensor unit, regulates the reading surface of the document PP, and serves as a transport unit that transports the document PP.

P is a recording medium in the form of a roll paper in the embodiment shown in the figure, and reproduces image information read by the image sensor unit 100 or image information transmitted from the outside in the case of a facsimile apparatus or the like. Is done. Numeral 110 denotes a recording head as recording means for forming an image on the recording medium P. Numeral 112 denotes a conveying means which conveys the recording medium P to a recording position of the recording head 110 and regulates a recording surface thereof. As a platen roller.

Reference numeral 120 denotes an operation panel on which switches and messages for inputting operations as input / output means, a display unit for notifying the status of the apparatus, and the like are arranged. Reference numeral 130 denotes a system control board as control means, which is provided with a control unit for controlling each unit, a drive circuit for photoelectric conversion elements, a processing unit for image information, a transmission / reception unit, and the like. 140 is a power supply of the apparatus.

FIG. 14 shows an example of a scanner as an image information processing apparatus constituted by using the flat bed type image sensor unit 200 according to the present embodiment. here,
5 is a transparent member capable of contacting the original PP and defining a reading surface;
Reference numeral 201 denotes a scanning belt as a feeding unit for mounting the image sensor unit 200 and scanning in the scanning direction DS, 202 denotes a feeding roller for driving the scanning belt, and 230 denotes a system control board as a control unit. And a control unit for controlling each unit, a drive circuit for the photoelectric conversion element, a processing unit for image information, a transmission unit, and the like. 240 is a power supply of the apparatus.

With the configuration described above, the mounting position of the imaging element and the mounting position of the sensor array are determined by the component accuracy of the positioning support and the component accuracy of the electric circuit board. For this reason, deviation between the optical axis of the imaging element and the light receiving portion of the sensor array due to work variation is improved, and it is possible to prevent a decrease in optical information from the document to the light receiving sensor and obtain a good image.

Even if the focal length of the image forming element becomes shorter and the distance from the surface of the lens array facing the document to the document reading position becomes extremely short, the positioning support is positioned before the lens array with respect to the transparent member. The abutting means abuts on the transparent member provided in the above. Therefore, it is possible to prevent the transparent member or the lens array on the effective optical path for image reading from being damaged, and to obtain a good image.

As a result, a more compact product configuration, which is the greatest advantage of the contact type image sensor and the flat bed type image sensor, can be realized.

[0043]

As described above, according to the present invention, it is possible to prevent the optical information from decreasing from the original to the light receiving element due to the displacement of the relative position between the image forming element and the light receiving element. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a contact type image sensor of the present invention.

FIG. 2 is a sectional view taken along line GG ′ of FIG.

FIG. 3 is a schematic perspective view of the present invention.

FIG. 4 is a sectional view taken along line HH ′ in FIG. 3;

FIG. 5 is a schematic perspective view of a contact image sensor according to a second embodiment of the present invention.

FIG. 6 is a sectional view taken along line II ′ of FIG. 5;

FIG. 7 is a schematic perspective view according to a second embodiment of the present invention.

FIG. 8 is a sectional view taken along the line JJ ′ of FIG. 7;

FIG. 9 is a schematic perspective view of a flatbed image sensor according to a third embodiment of the present invention.

FIG. 10 is a sectional view taken along the line KK ′ in FIG. 9;

FIG. 11 is a schematic perspective view according to a third embodiment of the present invention.

FIG. 12 is a sectional view taken along line LL ′ of FIG. 11;

FIG. 13 is a schematic cross-sectional view of an image information processing device of a contact type image sensor according to an embodiment of the present invention.

FIG. 14 is a schematic sectional view of an image information processing device of a flat bed type image sensor according to an embodiment of the present invention.

FIG. 15 is a schematic perspective view of a conventional contact image sensor.

FIG. 16 is a sectional view taken along line FF ′ of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st frame 2 2nd frame 3 Sensor array 4 Electric circuit board 5 Transparent member 6 Light source 61 Light guide plate 62 Housing 63 LED light source 7 Imaging element 71 Lens array 72, 73 Side plate 9 Positioning support body 91 Contact means 100 Sensor unit 102 feed roller 104 separation piece 106 platen roller 110 recording head 112 platen roller 120 operation panel 130 system control board 140 power supply 200 sensor unit 201 scanning belt 202 feed roller 230 system control board 240 power supply 1A first space 1B second space 1C Three spaces 1D Light source mounting surface 1E Imaging element mounting surface TC Focal length L Depth of field PP Document P Recording medium DM Longitudinal direction of support DS Short direction of support

Continued on the front page F term (reference) 5B047 AA01 BA01 BA02 BB02 BC02 BC05 BC16 5C051 AA01 BA04 DA03 DB01 DB22 DE21 5C072 AA01 BA01 CA05 DA21 DA25 EA07 SA03

Claims (5)

[Claims] 1. A light source for irradiating light to a reading surface of a document, a light receiving element for receiving reflected light from the document, an image forming element for forming an image of reflected light on the light receiving element, and these members are directly connected to each other. Or a frame for indirectly attaching, the image sensor unit to enter and reflect light to the original through a transparent member capable of contacting the reading surface of the original, wherein the imaging element and the light receiving element A positioning member for relatively positioning and supporting the frame is provided separately from the frame, and the positioning support member protrudes toward the document from the image forming element and comes into contact with the transparent member. Image sensor unit. 2. The image sensor unit according to claim 1, wherein said positioning means is formed integrally with said imaging element. 3. The image sensor unit according to claim 1, wherein the transparent member is attached to a predetermined portion of the frame. 4. The apparatus according to claim 1, wherein the transparent member is arranged separately from the frame.
An image sensor unit according to item 1. 5. A moving mechanism for performing a predetermined relative movement between the image sensor unit according to claim 1 and a document to be read, wherein the image sensor unit and the document are moved. An image reading apparatus for scanning an image of the original by relative movement of the image reading apparatus.