JPH02129971A - Close-contact image sensor - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a contact type image sensor suitably used in facsimile machines, text/image reading/input devices, and the like.

<Prior Art> Character/image reading/input devices using contact image sensors have been actively developed in recent years to contribute to miniaturization and cost reduction of the devices. Most of the contact image sensors mentioned above focus optical information from a document on the light receiving surface of the sensor, usually through a rod lens array, so the document and sensor must be separated by the conjugate length of the rod lens array. 20+m as a type image sensor unit
The thickness was about 30 m, and there was a natural limit to miniaturization. Furthermore, since a lens system is used, optical adjustment is required, and there is also the problem that the light transmission rate decreases.

Therefore, in order to solve the above problems, a method has been proposed that does not use a rod lens array, but instead uses an optical 7-eyeper plate in which a plurality of optical fibers are incorporated in an array in a substrate.

In the optical fiber plate, the light-receiving surface of the sensor is placed on one end of the original fiber, and the surface of the document to be read is brought into close contact or close to the other end, so that optical information from the document is guided to the light-receiving surface of the sensor through the optical fiber. Therefore, since no lens system is used, there is no need for optical adjustment, and the light transmission rate is sufficiently high, and by shortening the length of the optical fiber, an ultra-compact contact type image sensor unit is possible.

The second figure shows a cross section of the structure of a contact image sensor using an optical fiber plate. In FIG. 2, 1 is an optical fiber plate, 2 is a light emitting diode, and 51 is a light emitting diode array in which the light emitting diodes 2 are arranged in a play shape A substrate, 61 is a heat sink, 3 is a light receiving element array substrate on which the light receiving element array 31 is formed, 52
is a drive circuit board that drives the light receiving element array 31;
It is equipped with driving LSI4. Further, 62 is a support stand that supports the light receiving element array board 3 and the drive circuit board 52. The light emitted from the light emitting diode 2 crosses the optical fiber plate 1 obliquely and illuminates the original 7. The reflected light from the original passes through an optical fiber and is guided to the light-receiving surface of the light-receiving element door, where the information on the original is read. Further, the light receiving element 31 and the driving LSI 4 are connected by a wire bonding method.

The optical fiber plate 1 is an EMA type (Extra
An optical fiber plate 1a called "Mural Absorption" and an optical fiber plate 1b called "C1ear type" in which no absorber is interposed between each fiber are bonded and integrated. This is a C1ear type optical fiber plate that can irradiate the document surface across the optical fiber, and an EMA type optical fiber plate that reduces light leakage to adjacent optical fibers and provides high resolution characteristics. This is because it is possible to take advantage of the strengths of both.

<Problems to be Solved by the Invention> However, the configuration shown in FIG. 2 described above has a large number of parts and cannot be said to have good productivity.

The present invention has been devised in view of the above points, and maintains the excellent features of a contact type image sensor using an optical fiber plate, and can reduce the number of parts by simply changing the configuration. Moreover, it is an object of the present invention to provide an ultra-small contact type image sensor that has good productivity and can be manufactured at low cost.

<Means for Solving the Problems> In order to achieve the above object, the contact type image sensor of the present invention includes a light emitting diode play formed in a part of the drive circuit board that drives the light receiving element array, and more preferably a light emitting diode play. The structure is such that a circuit board and a light-receiving element play board on which a light-receiving element array is formed are bonded together.

<Function> As described above, by forming a light emitting diode array on a part of the drive circuit board that drives the light receiving element play according to the present invention, the number of parts can be reduced, resulting in good productivity and cost reduction. By adhering the drive circuit board and the light receiving element array board, an even more compact contact type image sensor can be obtained.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a cross-sectional view of the structure of the contact type image sensor in this embodiment.

In the figure, 1 includes an optical fiber plate, 2 a light emitting diode play, 3 a light receiving element array substrate on which a light receiving element array 31 is formed, 4 a driving LSI for driving the light receiving element array, and 5 an LSI 4 for driving a light receiving element. A circuit board in which a driving circuit and its peripheral circuits including a light emitting diode array 2 are formed on one board. Reference numeral 6 is an aluminum plate that serves to support the circuit board and dissipate heat from the light emitting diodes.

The optical fiber plate 1 is an EMA with an absorber that absorbs light interposed between each fiber as in the past.
(Extra Mural Absorption)
type optical fiber plate la and C1B without absorber
This is made by stacking AR-type optical fiber plates 1b.

The light emitted from the light emitting diode array 2 is C1ea
R-type optical fiber play) The original 7 is irradiated by diagonally crossing the optical fiber 1b. The reflected light from the original passes through the fibers of the C1ear type optical fiber plate lb and the EMA type optical fiber plate la and is guided to the light receiving surface of the light receiving element array 31, where information on the original is read. The light receiving element is scanned in the main scanning direction by a drive circuit 5 including an LSI 4. Further, in the sub-scanning direction, the document 7 is scanned by moving it.

Next, a specific method for manufacturing the contact type image sensor of this example will be explained.

Kazuzu, EMA type optical fiber plate la and C1ear
The molded optical fiber plate 1b is bonded with the optical fiber surfaces together using a transparent resin. Incidentally, the EMA type optical fiber plate 1a is partially cut off so as not to come into contact with the subsequent drive circuit.

The light receiving element array substrate 3 is manufactured by forming individual electrodes made of aluminum (Al) on a glass substrate, and then applying plasma CVD.
The a-3i film is deposited to a thickness of about 1 μm using D apparatus.

Further, a common electrode made of ITO is formed thereon to obtain a light receiving element array 31.

In this embodiment, the resolution is 8 lines/fi.

The light receiving length was set to 216 sa+, and 1,728 pixels were formed.

Further, the dimensions of the light-receiving element play board 3 are length 220×9 width 6III.

The circuit board 5 is a glass epoxy board on which a copper wiring pattern is formed, and the board surface is coated with an insulating resin. The wiring pattern of the circuit board is formed on both sides of the board, and is also formed on the part to be bonded to the light receiving element array board 3.

The size of the circuit board is 220 x 9 in length and 20 m in width. After gluing the light receiving element play board q to a predetermined position on the circuit board, the driving LSI 4 is die-bonded to the circuit board 5.
The light receiving element 31, the LSI 4° LSI 4, and the circuit board 5 are connected by wire bonding. Further, the light emitting diodes 2 are arranged at predetermined positions at a pitch of 2.5 square meters and connected to the circuit board by wire bonding. Note that the light emitting diode used is a yellow-green one with a central emission wavelength of 570 nm.

Next, the light-receiving surface of the light-receiving element play and the optical fiber surface of the EMA type optical 7 eyeper plate 1a are adhered and fixed with a transparent resin.

The contact type image sensor as an embodiment of the present invention manufactured as described above uses an optical fiber plate for the optical system, so that the light amount transmission rate is high, that is, the optical information illuminance at the sensor section is high. , the signal is several times larger than using a conventional rod lens array, and in the embodiment of the present invention, the drive circuit board and light source are integrated, and the sensor section is fixed with adhesive. Unlike conventional rod lens arrays, optical adjustment for focusing is not required, and in addition to the advantages of being ultra-miniaturized, cost reduction and productivity improvement have been realized. Although the case where an a-5i film is used as a light receiving element has been described, the present invention is not limited to the type of light receiving element, and it goes without saying that it can be applied to other thin film sensors or IC sensors. <Effects of the Invention> As explained above, the present invention maintains one of the excellent features of a contact type image sensor using an optical fiber plate, and provides a part of a drive circuit board for driving a light receiving element array. By forming a light emitting diode array on the wafer, we were able to reduce the number of parts and reduce the number of optical adjustment steps, improving productivity and lowering costs.In addition, it was possible to bond the drive circuit board and photodetector array board. By doing so, it is possible to obtain a contact-type image sensor that is even more miniaturized.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a structure of a contact type image sensor according to an embodiment of the present invention, and FIG. 2 is a view showing a structure cross section of a conventional contact type image sensor using an optical fiber plate in an optical system. 1... Optical fiber play) (la: EMA type optical fiber plate, 1b... Ctear type optical fiber plate), 2... Light emitting diode array, 3...
Light-receiving element array substrate, 31... Light-receiving element array, a, -
4... Drive LSI, 5... Circuit board (a board that integrates a light emitting diode array board and a drive circuit board), 6
... Aluminum plate (support plate and heat sink), 7... Manuscript.

Claims (1)

[Claims] 1. A light-emitting diode array that illuminates at least a document to be read; a light-receiving element array that receives reflected light from the document and converts it into an electrical signal; and electrically driving the light-receiving element array. What is claimed is: 1. A close-contact image sensor comprising a drive circuit, the light-emitting diode array being formed on a part of a drive circuit board forming the drive circuit.