JP3255762B2 - Complete contact image sensor unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a complete contact type image sensor unit for converting an optical image into an electric signal.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional full-contact type image sensor unit using an optical fiber array has a light receiving element array 4 formed on a semiconductor image sensor element 41.
2 is mounted so as to be in contact therewith, and a document 44 placed in close contact with the other end of the optical fiber
The optical information is proved by the 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]

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 varies greatly.
The sensitivity variation of the sensor is increased, and the performance of image reading is reduced. Also, from the original 44, the LED array 45
Up to a certain distance, the size of the unit itself was also large.

[0004]

In order to solve the above problems, an image sensor unit according to the present invention comprises an optical fiber array formed by arranging a plurality of optical fibers and an optical fiber array provided at one end of the optical fiber array. A plurality of light receiving element arrays, wherein the optical fiber comprises a central core, a clad provided on an outer surface of the core, and a light absorber layer provided on an outer surface of the clad. In a complete contact image sensor in which the other end of the fiber array has a document contact surface, it is disposed on the side surface of the optical fiber array,
A transparent plate having a light-shielding layer on the original contact surface side, an opaque substrate provided on a side of the transparent plate on a side different from the optical fiber array, and an opaque inside, and the original of the transparent plate
It is provided on the side different from the contact surface, and
And a surface light emitter . Further, the image sensor unit of the present invention includes an optical fiber array formed by arranging a plurality of optical fibers, and a plurality of light receiving element arrays provided on one end side of the optical fiber array, wherein the optical fibers are located at the center. And a light-absorbing layer provided on the outer surface of the clad. In the image sensor, a transparent plate is arranged in close contact with the side surface of the optical fiber array,
A complete contact type image sensor unit, wherein a surface light emitter (light source) is attached to one end surface of the transparent plate on the light receiving element array side.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention by the configuration described above, by guiding the light receiving element array without crossing the optical information (crosstalk) and unwanted optical information (flare light) by the optical fiber array light information from the originals, High quality and high resolution image reading can be realized . Also, close to the original
If the surface of the original can be uniformly illuminated by the surface light emitter,
In both cases, the size and weight of the image sensor unit itself can be reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image sensor according to an embodiment of the present invention will be described below with reference to the drawings.

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 a document, 2 is a light absorber layer provided at a specific pitch in the first optical fiber array, and 3 is in close contact with the side surface of the first optical fiber array The transparent glass plate 8 is provided with two opaque glass substrates sandwiching the optical fiber array 1 and the transparent glass plate 3.

FIG. 2 is a configuration diagram of an optical fiber constituting an optical fiber array. 11 is a core, 12 is a clad formed on the outer surface of the core 11, and 13 is a clad 12
Is a light absorber layer formed on the outer surface of the substrate.

FIG. 3 is a front sectional view of a complete contact type image sensor unit according to an embodiment of the present invention. 21 is an image sensor chip, 22 is an image sensor chip 21
A light receiving element array formed on the surface of the image sensor chip 21, an electrode provided on the surface of the image sensor chip 21, a circuit conductor layer 24 formed on the surface of the opaque glass substrate 28,
26 is an optical fiber array arranged so as to correspond to the light receiving element array 22, and 27 is a first optical fiber array 26.
28, a transparent glass plate arranged to be in close contact with the side surface of
Is an opaque glass substrate sandwiching the optical fiber array 26 and the transparent glass plate 27; 25 is a transparent light-curing insulating resin for mounting the image sensor chip 21 on the opaque glass substrate 28 and the optical fiber array 26; Is an EL light source for illuminating a document formed on the light receiving element array side of the transparent glass plate 27; 30 is a document to be read;
Reference numeral denotes a light-shielding layer provided on the side of the transparent glass plate 27 on which the original adheres.

Next, the details of the complete contact type image sensor unit configured as described above will be described in detail.

First, a light receiving element array 22 such as a phototransistor or a photodiode is mounted on a single crystal silicon substrate (wafer) by using a semiconductor process.
S, a device provided with an access circuit (not shown) such as a bipolar IC is manufactured. 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.

Next, a light absorbing layer 1 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.
The optical fiber array 1 (26) is formed by arranging a large number of optical fibers in parallel in a strip shape, and a transparent glass plate 3 (27) is attached so as to be in close contact with the side surface, and is made of two sheets of glass. An optical fiber array plate is produced by sandwiching the opaque glass substrate 28 and applying heat at about the glass melting point while applying pressure from both sides. 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 (the original contact side) of the transparent glass plate 3 (27) by a screen printing method,
Form one. Next, the image sensor chip 21 manufactured previously is connected to the light receiving element array 22 by the optical fiber array 1.
The electrode 23 is mounted so as to be connected to a predetermined position of the circuit conductor layer 24 by face-down bonding via an acrylate-based transparent photocurable insulating resin 25 so as to be in close contact with (26).

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 by using a thick-film printing method, and light from the EL light source 29 is made incident through the transparent glass plate 3 (27). The original 30 is illuminated through the 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 can pass to some extent.

At this time, the presence of the opaque glass substrate 28, the light absorber layer 31, and the like eliminates the light (flare light) from the LED array 19 directly entering the light receiving element array 22 without reaching the original 30. I was able to.

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).

As a result, when the light receiving element array of 8 dots / mm is used, the MTF value becomes 65 at 4 lp / mm.
%, And the sensitivity variation of the sensor is 25%, which is 25% in the past (using an LED array as a light source), but it is reduced to 15%, and a complete contact type image sensor unit capable of high-performance reading has been 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.

[0017]

As described above, according to the present invention, it is possible to reduce the variation in the sensitivity of the sensor, and to realize an ultra-compact and lightweight fully-contact image sensor unit capable of reading an image with high quality and high resolution. Can be.

[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.

FIG. 2 is a configuration diagram of an optical fiber according to an embodiment of the present invention.

FIG. 3 is a front sectional view of a complete contact type image sensor unit according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional image sensor unit.

[Explanation of symbols]

 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 light-curing insulating resin 26 optical fiber Array 27 Transparent glass plate 28 Opaque glass substrate 29 EL light source 30 Document 31 Light shielding layer

Continuation of front page (72) Inventor Shinji Fujiwara 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-3-38963 (JP, A)

Claims (9)

(57) [Claims] An optical fiber array formed by arranging a plurality of optical fibers; and a plurality of light receiving element arrays provided at one end of the optical fiber array, wherein the optical fibers have a central core, A perfect contact image sensor comprising a clad provided on the outer surface of the core and a light absorber layer provided on the outer surface of the clad, and the other end of the optical fiber array having a document contact surface. A transparent plate disposed on a side surface of the optical fiber array and having a light-blocking layer on the original contact surface side; an opaque substrate provided on a side surface of the transparent plate different from the optical fiber array and having an opaque interior; The transparent plate is provided on a surface side different from the original contact surface,
And a surface illuminator for irradiating the original . 2. A complete contact image sensor unit according to claim 1, wherein a thick film EL (electroluminescence) is attached as a surface light emitter on a surface of the transparent plate different from the original contact surface. 3. A complete contact image sensor unit according to claim 1, wherein the thin film EL is formed as a surface illuminant directly on a surface of the transparent plate different from the original contact surface. 4. A complete contact image sensor unit according to claim 1, wherein the thick film EL is formed as a surface illuminant on a surface of the transparent plate which is different from the original contact surface of the transparent plate by thick film printing. 5. An optical fiber array formed by arranging a plurality of optical fibers, and a plurality of light receiving element arrays provided at one end of the optical fiber array, wherein the optical fibers have a central core, In a perfect contact image sensor comprising a clad provided on the outer surface of the core and a light absorber layer provided on the outer surface of the clad, and the other end of the optical fiber array having a document contact surface. A transparent plate is disposed in close contact with a side surface of the optical fiber array, and a surface light emitter (light source) is attached to one end surface of the transparent plate on a light receiving element array side; unit. 6. A complete contact type image sensor unit according to claim 5, wherein a thick film EL (electroluminescence) is attached to one end of the transparent plate as a luminous body. 7. The complete contact type image sensor unit according to claim 5, wherein the thin film EL is directly formed on one end side of the transparent plate as a light emitting body. 8. The light emitting device according to claim 5, wherein a thick film EL is directly formed on one end side of the transparent plate by thick film printing.
The completely-contact image sensor unit as described. 9. The optical fiber array and a transparent plate sandwiched between two opaque substrates from both sides, and a light-shielding layer is provided on the other end surface side (document contact surface side) of the transparent plate. The completely-contact image sensor unit as described.