JPH03120948A - Close contact type image sensor - Google Patents

Abstract

PURPOSE:To realize a close contact type image sensor in direct contact with an original by arranging an element array board with a sensor array formed thereon, a wiring board delivering an output of the sensor array and a printed circuit board with an integrated circuit extracting an output of the sensor array in time series mounted thereon. CONSTITUTION:A CdS sensor array 1 is formed on the surface of a glass board 2 and an integrated circuit having a scanning function reading an output from the CdS sensor array 1 in time series is mounted on a printed circuit board 3. A support glass 4 supports the glass board 2, a connection glass board 11 and the printed circuit board 3. A GaP light emitting diode chip is mounted on a printed circuit board as a light source 6 and the light from the source is collected to a read position of an original 7 through the support glass 4 and the glass board 2. Thus, the close contact type image sensor receiving the reflected light directly from the original is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a contact type image sensor, and particularly to a contact type image sensor that directly reads an image using a method of reading an image through a lens system as used in facsimiles, scanners, etc. Regarding sensors.

In the case of a conventional facsimile machine, an IC image sensor (IC image sensor) is used to read a document and convert it into an electrical signal, which is made by fabricating a large number of highly densely integrated photodiodes in a row using semiconductor integration technology and integrating them with a scanning circuit. MO3 type image sensor, CCD image sensor) is used. This image sensor uses a contact type image sensor to miniaturize the device, and uses a photoelectric conversion element array having the same size as the document size and a selfoc lens as a light guide system, and has an optical path length of 10 to 301EII. is used. An example of the structure of such a contact type image sensor unit will be explained using FIG. 5 and FIG. 6. In FIG. 5, the photoelectric conversion element 1 is a sensor that utilizes photoconduction of a CdS diode, and a CdS sensor array in which these CdS sensors are arranged in a row is formed on a glass substrate 2. An integrated circuit having a scanning function for reading out the output of the glass substrate 2 in time series is mounted on the printed circuit board 3.

Support glass 4 mechanically connects glass substrate 2 and printed circuit board 3. The output terminal of the glass substrate 2 and the input terminal of the printed circuit board 3 are electrically connected by wire bonding.

The lost lens array 5 transfers the image of the document 7 to the CdS sensor array 1.
An erect, same-size image is formed on top. The light source 6 that illuminates the original 7 has a GaP light emitting diode chip mounted on a printed circuit board.
A plastic lens focuses light on the document reading position. The document 7 is run by rollers 8 and is conveyed so as to always pass the reading position.

Next, according to FIG. 6, the output terminal of CdS sensor array 1 and each Cd
The connection with the S sensor will be explained.

The CdS sensors are formed in a row on the Ig at a density of eight. Thirty-two adjacent sensors are connected as one block. In an A4 size contact image sensor, the number of sensors is 1728, which is divided into 54 blocks. One electrode of the 32 sensors in one block is connected to one common electrode (hereinafter referred to as a common electrode). The common electrode has a pitch of 4cm and is located at C of the glass substrate 2.
It is arranged along the side in the direction of the dS sensor row. CdS
The other electrode of each block is the 1st, 2nd, ・
...Connected to the wiring connecting the 32nd comrades (hereinafter referred to as individual wiring). Individual wiring is Cd on glass substrate 2
N individual electrodes are formed in the direction of the S sensor column, and one individual electrode for connecting the individual wiring to an external circuit is arranged between each individual electrode and the common electrode. Since these electrical connections cannot be made on the same plane, multilayer wiring made of polyimide resin is used where necessary.

When the n-th individual electrode is expressed as na1, and the m-th common electrode is expressed as mb, electrodes for connection to an external circuit are arranged along the side of the glass substrate 2 in the CdS sensor column direction in the following order. la.

lb, 2a+2b, ”'31a, 31b, 3
2a, 32b+ 33bt34b,...53b, 5
4b0 A total of 86 electrodes are arranged along the side of the glass substrate 2 in the direction of the CdS sensor array, and are electrically connected to corresponding connection bats on the printed circuit board 3 by wire bonding. m by mechanically selecting the nth individual electrode and the mth common electrode by a scanning circuit.
A matrix method is used to read out the nth sensor output of the flock.

Problems to be Solved by the Invention However, according to the above example, even a contact type image sensor requires a rod lens array.

It is also necessary to adjust the focus of the rod lens array.
There is a problem in that image quality deteriorates when the position of the rod lens array deviates from the position at the time of adjustment.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a contact image sensor that directly inputs reflected light from a document without using a rod lens array.

Means for Solving the Problems In order to achieve the above object, the contact image sensor of the present invention includes an element array substrate on which a photoelectric conversion element array is formed facing a document, and an element array substrate on which a photoelectric conversion element array is formed adjacent to the element array substrate. The present invention is characterized by comprising a wiring board on which wiring is formed to transmit the output of the wiring, and a printed circuit board on which an integrated circuit having a scanning mechanism that sequentially reads the output of the wiring is mounted.

Further, it is preferable that the element array substrate is a glass substrate, and the document illumination light is transmitted through the glass substrate to illuminate the document. Furthermore, it is preferable that the output terminal of the element array board and the input terminal of the wiring board corresponding to this output terminal be electrically connected by printing a conductive paste. Furthermore, it is preferable that the uppermost layer of the element array board and the wiring board facing the original is a glass layer. Further, it is preferable that each output terminal of the wiring board is arranged at a shorter interval in the direction of the photoelectric conversion element array than the corresponding input terminal. Further, an element array glass substrate on which a photoelectric conversion element array is formed facing the original, and a printed circuit board mounted with an integrated circuit adjacent to the element array glass substrate and having a scanning mechanism for sequentially reading the output of the photoelectric conversion element array. It is preferable that a document illumination device is provided on the opposite side of the element array glass substrate from the original, and illumination light passes through the element array glass substrate to illuminate the original.

Reflected light from a document directly facing the photoelectric conversion element array formed on the active element array substrate is incident on the photoelectric conversion element array formed on the active element array substrate. Therefore, the distance between the element array substrate and the document can be shortened. The output from the element array board is transmitted to the integrated circuit of the printed circuit board via the wiring of the wiring board, and the original is sequentially read in the column direction of the photoelectric conversion element array.

By using a glass substrate as the element array substrate, providing illumination on the opposite side of the glass substrate from the original, and transmitting illumination light through the glass substrate, there is no need to increase the distance between the original and the element array substrate for illumination.

By printing the output terminal of the element array board and the input terminal of the wiring board with conductive paste and electrically connecting them, the height of the connection part can be lowered and the distance between the element array board and the original can be shortened. be able to.

By making the top layer of the element array board and wiring board facing the original a glass layer, the element array board, the wiring board, and their connection parts are prevented from abrasion with the original.

Protect from moisture, dust, etc.

In addition, by arranging each output terminal of the wiring board in the direction of the photoelectric conversion element array so that it is shorter than the arrangement interval of the corresponding input terminal, the arrangement interval of the input terminals of the printed circuit board connected to the wiring board can be shortened. . This allows the printed circuit board to be made smaller. Further, the element array glass substrate and the printed circuit board are directly connected, and the output of the photoelectric conversion element array is sequentially read by a scanning mechanism mounted on the printed circuit board.

Since illumination light is transmitted through the glass substrate by illumination provided on the opposite side of the glass substrate to the side facing the original, the distance between the glass substrate and the original can be narrowed.

EXAMPLE Hereinafter, an example of the present invention will be explained using FIGS. 1 to 4.

FIG. 1 is a diagram showing the structure of a first embodiment of the present invention.

CdS sensor array 1 is 17 when reading an A4 size document by forming CdS sensors in one row at a density of 8 on IW.
Consists of 28 pieces. A CdS sensor array 1 is formed on the surface of the glass substrate 2. CdS on printed circuit board 3
An integrated circuit having a scanning function for reading out the output from the sensor array 1 in time series is mounted thereon. Support glass 4
supports a glass substrate 2, a connection glass substrate 11 (described later), and a printed circuit board 3. The illumination source 6 is Ga on the printed circuit board.
Mounted with a P light emitting diode chip, supported by a plastic lens4. Light is transmitted through the glass substrate 2 and focused on the reading position of the original 7. Original 7 is on roller 8
Run with The light shielding layer 9 is provided on the CdS sensor array 1 of the glass substrate 2 and forms an illumination window 10 to focus illumination light on the reading position of the original 7. A connection wiring 12 for transmitting the output of the CdS sensor array 1 to the integrated circuit of the printed circuit board 3 is formed on the connection glass substrate 11, and this connection wiring 12 and a glass substrate connection electrode 19 on the glass substrate 2, which will be described later, are electrically connected by printed connections 13 formed by printing conductive silver paste. The connection wiring 12 and a printed circuit board connection electrode head provided on the printed circuit board 3, which will be described later, are electrically connected by a printed circuit board connection part 14 constructed by a known method such as wire bonding or soldering of a flexible copper wire film. There is.

The wear-resistant layer 15 is a thin glass layer of about 50 μm provided to allow the document 7 to run smoothly over the CdS sensor array 1, and is bonded with an adhesive 16 made of transparent ultraviolet curing resin. The sensor unit base 17 is a glass substrate 2. Printed circuit board 3. Support glass 4. Lighting source 6. The connection glass substrate 11 is contained and supported. The original 7 is guided by the input guide plate 18 and placed in the CdS sensor array 1.
is conveyed by rollers 8 to the reading position.

The distance between the surface of the wear-resistant layer 15 and the surface of the CdS sensor array 1 is set to 200 μm or less to ensure a predetermined reading accuracy. Therefore, the thickness of the adhesive 16 is 10 to 10
It is approximately 0 μm. The thickness of the printed connection part 13 is 50μ
Formed with a thickness of less than m. This is to keep the distance between the surface of CdS sensor array 1 and the surface of wear-resistant layer 15 to 200 μm or less.

On the other hand, since the printed circuit board connection section 14 is located away from the CdS sensor array 1 and is not subject to such height restrictions, a known connection method such as wire bonding is used. Furthermore, since the connecting glass plate 11 and the printed circuit board 3 have different coefficients of thermal expansion, wire bonding, flexible copper wire, or the like is preferable in order to absorb this difference.

FIG. 2 is a diagram showing the arrangement of the connection wiring 12 on the connection glass substrate 11 and its arrangement with the glass substrate 2 and the printed circuit board 3. The wiring connections are the same as the wiring diagram shown in FIG. Common electrode (lb, 2b...54b) is 4m
Individual electrodes (1a.

2a...32a) are arranged between the common electrode and the pitch of each electrode is 2wR. A connecting portion ff512 and a printed circuit board connecting electrode silver are arranged opposite to these electrodes. The glass substrate connection electrode 19 and the connection wiring 12 are printed connection parts 13 formed by printing conductive paste.
However, since the pitch of the printing connection portions 13 is 2 m, sufficient printing accuracy can be ensured.

FIG. 3 shows another embodiment of the connection wiring 12 on the connection glass substrate 11. The connecting portion between the glass substrate 2 and the connecting glass substrate 11 is the same as the embodiment shown in Fig. 2, but the connecting portion between the connecting glass substrate 11 and the printed circuit board 3 is connected by shortening the pitch between each connecting electrode. The length of the electrode row is shortened. For this reason, the connection wiring 12 has a stepped shape as shown in FIG.

Note that the glass substrate connection electrode 19 and the corresponding printed circuit board connection electrode silver may be connected by a vertical line or a diagonal line. By doing so, it is possible to reduce the size of the printed substrate 3, and the manufacturing cost can be reduced.

Next, a second embodiment will be explained with reference to FIG. Note that the same symbols as in FIG. 1 represent parts with the same function.

The difference from the first embodiment is that the connection glass substrate 11 is removed.
The width of the glass substrate 20 (the length in the direction perpendicular to the column direction of the CdS sensor array 1) is long, and the connection to the printed circuit board 3 is made by wire bonding, a printed circuit board connection part 14 such as a flexible copper wire, etc. be. In this embodiment, since the connecting glass substrate 11 is eliminated, manufacturing becomes easier, but since the width of the glass substrate 2 becomes larger, it cannot be said that the overall manufacturing cost necessarily decreases. The reason why the width of the glass substrate 2 is made longer is to use a connection method such as wire bonding that can absorb the difference in thermal expansion between the glass substrate 2 and the printed circuit board 3. By using durable printed connections 13, the width of the glass substrate 2 can be made the same length as in the first embodiment, reducing the overall manufacturing cost.

Effects of the Invention As is clear from the above description, the present invention provides an element array substrate on which a sensor array is formed, a wiring board that transmits the output of the sensor array, and an integrated circuit that extracts the output of the sensor array in time series. By arranging the printed circuit board mounted thereon adjacently, it is possible to realize a contact type image sensor that is in direct contact with the original. The element array board and printed circuit board are still placed adjacent to each other,
A similar close-contact image sensor can be realized.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of the first embodiment of the present invention, FIG.
3 is a diagram showing the wiring arrangement of the connection glass substrate, FIG. 4 is a diagram showing the configuration of the second embodiment, FIG. 5 is a diagram showing the configuration of an example of a conventional contact type image sensor, and FIG. The figure is a diagram showing connections on a glass substrate. 1... CdS sensor array 2... Glass substrate, 3
...Printed circuit board, 4...Support glass, 6...
- Illumination source, 9... Light shielding layer, 10... Illumination window, 11
... Connection glass substrate, 12 ... Connection wiring, 13 ...
・Printed connection part, 14... Printed circuit board connection part, 15.
...Abrasion resistant layer, 16...Adhesive.

Claims (6)

[Claims] (1) An element array board on which a photoelectric conversion element array is formed facing the original; a wiring board adjacent to the element array board on which a wiring is formed for transmitting the output of the photoelectric conversion element array; and the output of the wiring is sequentially transmitted. A contact image sensor comprising: a printed circuit board on which an integrated circuit having a scanning mechanism for reading is mounted; (2) The contact image sensor according to claim 1, wherein the element array substrate is a glass substrate, and the document illumination light is transmitted through the glass substrate to illuminate the document. (3) The close contact according to claim 1 or 2, characterized in that the output terminal of the element array board and the input terminal of the wiring board corresponding to this output terminal are electrically connected by printing a conductive paste. type image sensor. (4) Claim 1 characterized in that the uppermost layer of the element array board and the wiring board facing the original is a glass layer.
, 2 or 3. The close-contact image sensor according to . (5) Claim 1, 2, 3 or 4, characterized in that the arrangement interval of each output terminal of the wiring board in the direction of the photoelectric conversion element array is shorter than the arrangement interval of each corresponding input terminal.
The image sensor described. (6) A printed circuit board on which is mounted an element array glass substrate on which a photoelectric conversion element array is formed facing the original, and an integrated circuit that is adjacent to the element array glass substrate and has a scanning mechanism that sequentially reads the output of the photoelectric conversion element array. and a document illumination device, which is provided on a side of the element array glass substrate opposite to the document, and illuminates the document by transmitting illumination light through the element array glass substrate.