JP3551173B2 - Image sensor unit - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a complete contact type image sensor unit that converts an optical image into an electric signal.
[0002]
[Prior art]
As shown in FIG. 4, a conventional full-contact type image sensor unit using an optical fiber array is mounted so that a light receiving element array 42 formed on a semiconductor image sensor element 41 comes into contact with the optical fiber array 43. The document 44 placed in close contact with the side is certified from above by the LED array 45, and the optical information is guided to the light receiving element array 42 using the optical fiber array 43 and converted into an image signal.
[0003]
[Problems to be solved by the invention]
However, in the above-described image sensor unit, since the LED array 45 is used as the light source, the illuminance of the document surface greatly varies, the variation in the sensitivity of the sensor increases, and the performance of image reading deteriorates. Further, it is necessary to keep a certain distance from the document 44 to the LED array 45, and the size of the unit itself is also large.
[0004]
[Means for Solving the Problems]
In order to solve the above problem, an image sensor unit according to the present invention includes a surface light source, a transparent plate for illuminating a document through light from the surface light source, and the illuminated document. An optical fiber array for guiding light from the optical fiber array, and a light receiving element array to which light from the optical fiber array is guided, the surface light emitter has an area smaller than the upper surface of the transparent plate, and , Provided within the range of the upper surface of the transparent plate so as not to exceed the side surface of the transparent plate.
[0005]
The image sensor unit of the present invention further includes a surface light source, a transparent plate for illuminating a document through light from the surface light source, and a light guide for guiding light from the illuminated document. An optical fiber array; and a light receiving element array to which light from the optical fiber array is guided, wherein the surface light emitter has a thickness smaller than a distance between an upper surface of the transparent plate and a lower surface of the light receiving element array. The lower surface portion is provided so as to contact the upper surface of the transparent plate, and the upper surface portion is provided lower than the lower surface of the light receiving element array.
[0006]
The image sensor unit of the present invention further includes a surface light source, a transparent plate for illuminating a document through light from the surface light source, and a light guide for guiding light from the illuminated document. An optical fiber array, comprising a light receiving element array to which light from the optical fiber array is guided, wherein the surface light source light source, the lower surface portion is provided in contact with the upper surface of the transparent plate, I do.
[0007]
Further, the image sensor unit of the present invention includes an optical fiber array formed by aligning a plurality of optical fibers, and a light receiving element array provided on one end side of the optical fiber array, and is in close contact with a side surface of the optical fiber array. A transparent plate, and a surface light source is attached to one end surface of the transparent plate on the light receiving element array side.
[0008]
According to the present invention, the surface of the original is uniformly illuminated by the EL, which is a light emitter close to the original, and the optical information from the original is crossed with the optical information by the optical fiber array and unnecessary optical information is provided. By guiding the light to the light receiving element array without (flare light), high quality and high resolution image reading can be realized, and the size and weight of the image sensor unit itself can be reduced.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
An image sensor unit according to a first aspect of the present invention includes a surface light source, a transparent plate for illuminating a document through light from the surface light source, and light from the illuminated document. An optical fiber array for guiding the light, and a light receiving element array to which light from the optical fiber array is guided, the surface light emitter has an area smaller than the upper surface of the transparent plate, and the transparent It is provided within the range of the upper surface of the transparent plate so as not to exceed the side surface of the plate.
[0010]
The image sensor unit according to the second aspect of the present invention is characterized in that the surface light source is provided within a range of the upper surface of the transparent plate with a space between both side surfaces of the transparent plate. .
[0011]
In the image sensor unit according to the third aspect of the present invention, the surface light source has a thickness smaller than a distance between an upper surface of the transparent plate and a lower surface of the light receiving element array, and a lower surface portion of the light emitting device array has The light receiving element array is provided so as to be in contact with the upper surface and to have an upper surface portion lower than the lower surface of the light receiving element array.
[0012]
Further, an image sensor unit according to a fourth aspect of the present invention includes a surface illuminant light source, a transparent plate for illuminating an original through light from the surface illuminant light source, and an illuminated original. An optical fiber array for guiding light from the optical fiber array, and a light receiving element array to which light from the optical fiber array is guided, wherein the surface light emitter emits a light between an upper surface of the transparent plate and a lower surface of the light receiving element array. The light-receiving element array is characterized in that it has a thickness smaller than that of the light-receiving element array, and a lower surface portion thereof is in contact with the upper surface of the transparent plate, and an upper surface portion thereof is lower than the lower surface of the light receiving element array.
[0013]
An image sensor unit according to a fifth aspect of the present invention includes a surface illuminant light source, a transparent plate for illuminating an original through light from the surface illuminant light source, and an illuminated original. An optical fiber array for guiding the light of the light, and a light receiving element array to which the light from the optical fiber array is guided, and the surface light emitter is provided such that a lower surface portion thereof is in contact with the upper surface of the transparent plate. Is characterized in that:
[0014]
In the image sensor unit according to the sixth aspect of the present invention, the surface light source has a smaller area than the upper surface of the transparent plate, and the upper surface of the transparent plate does not exceed the side surface of the transparent plate. It is characterized by being provided in the range of.
[0015]
In the image sensor unit according to the seventh aspect of the present invention, the surface light source is formed directly on the upper surface of the transparent plate.
[0016]
An image sensor unit according to an eighth aspect of the present invention includes an optical fiber array formed by aligning a plurality of optical fibers, and a light receiving element array provided at one end of the optical fiber array. A transparent plate is disposed in close contact with the side surface of the array, and a surface light source is attached to one end surface of the transparent plate on the light receiving element array side.
[0017]
The image sensor unit according to the ninth aspect of the present invention is characterized in that the surface illuminant light source is EL (electroluminescence).
[0018]
An image sensor unit according to another aspect of the present invention includes an optical fiber array formed by aligning a plurality of optical fibers, and a plurality of light receiving element arrays provided at one end of the optical fiber array. The optical fiber is composed of a central core, a clad provided on the outer surface of the core, and a light absorber layer provided on the outer surface of the clad. In the complete contact type image sensor, a transparent plate is disposed in close contact with the side surface of the optical fiber array, and the optical fiber array and the transparent plate are sandwiched between two opaque substrates from both sides. A light-emitting body (light source) is provided on the side (light-receiving element array side), and a light-blocking layer is provided on the other end (document contact surface side).
[0019]
An image sensor unit according to another aspect of the present invention is characterized in that a thick film EL (electroluminescence) is attached to one end of a transparent plate as a luminous body.
[0020]
Further, an image sensor unit according to another aspect of the present invention is characterized in that the thin film EL is directly formed on one end side of the transparent plate as a light emitting body.
[0021]
An image sensor unit according to another aspect of the present invention is characterized in that a thick film EL as a light emitter is formed directly on one end side of a transparent plate by thick film printing.
[0022]
As a specific means, an EL capable of surface emission is used as a light source, and this is formed directly on a transparent glass plate which is a slit for receiving illumination light.
[0023]
Hereinafter, an image sensor according to an embodiment of the present invention will be described with reference to the drawings.
[0024]
FIGS. 1A and 1B are a sectional view and a plan view, respectively, of an optical fiber array plate of a complete contact image sensor according to an embodiment of the present invention. 1 is an optical fiber array for guiding optical information from an original, 2 is a light absorber layer provided at a specific pitch in the first optical fiber array, 3 is closely attached to the side of the first optical fiber array A transparent glass plate 8 is provided with two opaque glass substrates sandwiching the optical fiber array 1 and the transparent glass plate 3.
[0025]
FIG. 2 is a configuration diagram of an optical fiber constituting the optical fiber array. Reference numeral 11 denotes a core, 12 denotes a clad formed on the outer surface of the core 11, and 13 denotes a light absorber layer further formed on the outer surface of the clad 12.
[0026]
FIG. 3 is a front sectional view of a complete contact type image sensor unit according to the embodiment of the present invention. 21 is an image sensor chip, 22 is a light receiving element array formed on the surface of the image sensor chip 21, 23 is an electrode provided on the surface of the image sensor chip 21, and 24 is formed on the surface of an opaque glass substrate 28. Circuit conductor layer, 26 is an optical fiber array arranged so as to correspond to the light receiving element array 22, 27 is a transparent glass plate arranged so as to be in close contact with the side surface of the first optical fiber array 26, and 28 is an optical fiber Two opaque glass substrates sandwiching the array 26 and the transparent glass plate 27, 25 is an opaque glass substrate 28 and a transparent light-curing insulating resin for mounting the image sensor chip 21 on the optical fiber array 26, and 29 is a transparent glass An EL light source for illuminating a document formed on the light receiving element array side of the plate 27, 30 is a document to be read, and 31 is a transparent A light shielding layer provided on the original contact surface of the scan plate 27.
[0027]
Next, details of the complete contact type image sensor unit configured as described above will be described in detail.
[0028]
First, using a semiconductor process, a single crystal silicon substrate (wafer) on which a light receiving element array 22 such as a phototransistor or a photodiode and an access circuit (not shown) such as a CCD, a MOS, or a bipolar IC are provided. Each electrode 23 has a structure in which an Au wire bump is formed on an Al electrode by a wire bonder. Thereafter, the wafer is cut by a high-precision dicing technique to produce a semiconductor image sensor chip 21.
[0029]
Next, a light-absorbing layer 13 having a thickness of 2 to 3 μm is formed on the outer surface of the cladding 12 of the optical fiber having a diameter of about 25 μm, and a number of these optical fibers are arranged in parallel in a strip to form an optical fiber array 1 (26). A transparent glass plate 3 (27) is assembled so as to be in close contact with the side surface, sandwiched between two opaque glass substrates 28 made of two glasses, and heat is applied to both sides of the glass so as to apply heat of about the glass melting point while applying pressure. Make a plate. Next, the circuit conductor layer 24 is formed on one end surface of the opaque glass substrate 28 by using a noble metal such as Au or Ag-Pt by a screen printing method or a flexible printed circuit board. Further, a black resin is applied to the other end of the transparent glass plate 3 (27) (document close contact surface side) by a screen printing method to form a light shielding layer 31. Next, the image sensor chip 21 manufactured earlier is face-down bonded via an acrylate-based transparent light-curable insulating resin 25 so that the light receiving element array 22 is in close contact with the optical fiber array 1 (26). Are mounted so as to be connected to predetermined positions of the circuit conductor layer 24.
[0030]
Using this complete contact type image sensor, a thick film EL light source 29 is mounted on the light receiving element array side of the transparent glass plate 27 using a thick film printing method, and light from the EL light source 29 is transmitted to the transparent glass plate 3 ( 27), and the original 30 is illuminated through the optical fiber array 1 (26). At this time, the light transmittance of the light absorber layer 13 of the optical fiber constituting the optical fiber array 1 (26) is set to about 20% so that light passes through to some extent.
[0031]
At this time, the presence of the opaque glass substrate 28, the light absorber layer 31, and the like can eliminate light (flare light) from the EL light source 29 that directly enters the light receiving element array 22 without reaching the original 30. Was.
[0032]
Optical information from the original 30 is guided to the light receiving element array 22 by the optical fiber array 1 (26) in a one-to-one correspondence without crossing of light (crosstalk).
[0033]
As a result, when an 8 dots / mm light receiving element array is used, the MTF value is 65% at 4 lp / mm, and the sensitivity variation of the sensor is 25%, which is 25% of the conventional (LED array is used as a light source). Thus, a complete contact type image sensor unit capable of high performance reading was realized. Further, the distance between the light source and the document surface can be reduced from the conventional 10 mm to 1.5 mm, and the size and weight of the entire sensor unit can be reduced to about half.
[0034]
【The invention's effect】
As described above, according to the present invention, it is possible to reduce the sensitivity variation of the sensor, and to realize an ultra-compact and lightweight image sensor unit capable of reading an image with high quality and high resolution.
[Brief description of the drawings]
FIG. 1A is a side sectional view of an optical fiber array plate according to an embodiment of the present invention. FIG. 1B is a plan view of the same. FIG. 2 is a configuration diagram of an optical fiber according to an embodiment of the present invention. FIG. 4 is a front sectional view of a complete contact type image sensor unit in an example. FIG. 4 is a sectional view of a conventional image sensor unit.
REFERENCE SIGNS LIST 1 optical fiber array 2 light absorber layer 3 transparent glass plate 8 opaque glass substrate 11 core 12 clad 13 light absorber layer 21 image sensor chip 22 light receiving element array 23 electrode 24 circuit conductor layer 25 transparent photocurable insulating resin 26 optical fiber Array 27 Transparent glass plate 28 Opaque glass substrate 29 EL light source 30 Document 31 Light shielding layer

Claims (9)

A surface light source, a transparent plate for illuminating a document through light from the surface light source, an optical fiber array for guiding light from the illuminated document, and the optical fiber array Light receiving element array to which light from
The surface light emitter has an area smaller than the upper surface of the transparent plate, and is provided within a range of the upper surface of the transparent plate so as not to exceed the side surface of the transparent plate.
An image sensor unit, characterized in that: 2. The image sensor unit according to claim 1, wherein the surface light source is provided within a range of an upper surface of the transparent plate at an interval from both side surfaces of the transparent plate. 3. The surface light source has a thickness smaller than the distance between the upper surface of the transparent plate and the lower surface of the light receiving element array,
The image sensor unit according to claim 1, wherein the lower surface portion is provided so as to contact the upper surface of the transparent plate, and the upper surface portion is provided lower than the lower surface of the light receiving element array. . A surface light source, a transparent plate for illuminating a document through light from the surface light source, an optical fiber array for guiding light from the illuminated document, and the optical fiber array Light receiving element array to which light from
The surface light emitter has a thickness smaller than the distance between the upper surface of the transparent plate and the lower surface of the light receiving element array,
The lower surface portion is provided so as to contact the upper surface of the transparent plate, and the upper surface portion is lower than the lower surface of the light receiving element array,
An image sensor unit, characterized in that: A surface light source, a transparent plate for illuminating a document through light from the surface light source, an optical fiber array for guiding light from the illuminated document, and the optical fiber array Light receiving element array to which light from
The surface light source, the lower surface portion is provided in contact with the upper surface of the transparent plate,
An image sensor unit, characterized in that: The surface illuminant light source has an area smaller than the upper surface of the transparent plate, and is provided within a range of the upper surface of the transparent plate so as not to exceed a side surface of the transparent plate. 5. The image sensor unit according to 5. The image sensor unit according to claim 1, wherein the surface light source is formed directly on an upper surface of the transparent plate. An optical fiber array formed by aligning a plurality of optical fibers, and a light receiving element array provided on one end side of the optical fiber array,
An image sensor unit, wherein a transparent plate is disposed in close contact with the side surface of the optical fiber array, and a surface light source is attached to one end surface of the transparent plate on the light receiving element array side. 9. The image sensor unit according to claim 1, wherein the surface light source is an EL (electroluminescence).

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