JPH0724847Y2 - Reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a reading device such as a contact image sensor.

[Prior art and its problems]

Recently, the development of contact image sensors has become active,
According to the reading system of the sensor, the size of the document is substantially
A long reading device corresponding to 1: 1 is brought into close contact with a document, a light source arranged in the device projects the document, receives the reflected light, and photoelectrically converts this to obtain a read signal.

The reading device has its longitudinal direction (main scanning direction).
And at the same time, the document is moved so as to be orthogonal to the main scanning direction (the moving direction is called the sub-scanning direction), whereby the two-dimensional image of the document can be read.

FIG. 3 is a sectional view of the reading device in the sub-scanning direction,
In the figure, 1 is a glass substrate, 2 is a photoelectric conversion element array, 3 is an element selection IC chip for sequentially reading signals from the element array, and 4 is a light source in which a plurality of light emitting diodes are arranged. is there. The glass substrate 1 and the light source 4 are arranged on a metal substrate support member 5.

A printed circuit board 6 is arranged on the other surface of the substrate support member 5, and an amplifier circuit,
A signal processing circuit composed of a signal correction circuit, a reference circuit, and the like is mounted in a chip. The signal processing circuit and the IC chip 3 are connected by the flexible cable 7.

In a reader with such a structure, an element selection IC
Since the chip 3 is mounted on the glass substrate 1, and the flexible cable connection terminal must be formed on the glass substrate for mounting the chip 3, the glass substrate mounts the photoelectric conversion element array. However, when a large number of sensors are manufactured at one time, the number of glass substrates is limited by the size of the glass substrate, resulting in a decrease in manufacturing efficiency and an increase in manufacturing cost.

Further, since the reading device uses a flexible cable, it has a complicated structure such as forming a connecting terminal, and the connecting portion requires gold plating, resulting in a high manufacturing cost.

[Purpose of device]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems, to improve the manufacturing efficiency, and to provide a reading device in which the manufacturing cost is reduced.

[Means for solving problems]

According to the present invention, a substrate, a photoelectric conversion element mounting substrate disposed on the substrate, and a signal processing circuit mounting substrate disposed on the substrate and arranged in parallel with the substrate are provided. Element selection IC near the edge on the processing circuit mounting board
Is provided, and the electrode of this IC and the electrode formed on the photoelectric conversion element mounting substrate are wire-bonded to each other.

〔Example〕

 Hereinafter, the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a sectional view of the reading device of the present invention in the sub-scanning direction.

In the figure, 8 is a glass substrate, 9 is a photoelectric conversion element array formed on the substrate 8, 10 is a printed circuit board, and the element selection IC chip 11 and signal processing are provided on the substrate 10. A platform type chip (not shown) composed of a circuit is mounted. The element selection IC chip 11 is composed of an analog switch, a shift register, and the like, by which a read signal can be selected for each element. Further, the signal processing circuit is composed of an amplifier circuit, a signal correction circuit, a reference circuit, etc., and the read signal obtained from the IC chip 11 is amplified to (i) ... 1.0 to 2.0 V by the signal processing circuit (ii). ..The output information of each element is corrected and image information with uniform sensitivity is output. (Iii) ... Signal processing such as outputting the reference level necessary for A / D conversion of the image information is performed. Be seen.

The glass substrate 8 and the printed circuit board 10 are placed on a metal substrate supporting member 12, and the substrate supporting member 12 further includes a LE substrate.
A light source 13 composed of D or the like is additionally provided, and the light source 13 passes through the glass substrate 8 and projects the document 14.

Reference numeral 15 is a connector for leading a read signal output from the signal processing circuit to the outside.

In the reader having such a configuration, the IC chip is not mounted on the glass substrate, and it is only necessary to form the wire bonding pad for connecting the IC chip instead of the terminal for connecting the flexible cable. The glass substrate can be made extremely small.

Further, the glass substrate 8 and the printed circuit board 10 can be made to be extremely close to each other, and therefore wire bonding can be employed instead of the flexible cable when connecting the both.

Further, according to the reader of the present invention, the thickness of the printed circuit board 10 can be made smaller than that of the glass substrate 8 as shown in FIG. 2, which has the following advantages. In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals.

That is, the height difference between the wire bonding pad of the IC chip 11 and the wire bonding pad of the glass substrate 8 becomes extremely small, so that the wire bonding is accurately and easily performed. Further, although the resin layer 16 is coated on the IC chip 11, it is possible to set the height of the IC chip 11 to be approximately the same as the height of the glass substrate 8. The height of the resin layer 16 applied on the glass substrate can be reduced so that the roller 17 does not come into contact with the resin layer 16, and as a result, even if the glass substrate 8 is further reduced, the original is not fed. Will not be hindered by.

[Effect of device]

As described above, according to the reader of the present invention, the substrate for mounting the photoelectric conversion element can be made small, and further, the flexible cable is not required, whereby the manufacturing efficiency can be increased and the manufacturing cost can be reduced.

Further, according to the reader of the present invention, the wiring connecting the photoelectric conversion element and the signal processing circuit is shortened, which reduces the influence exerted on the wiring by the noise source, and as a result, the S / N ratio A large, high performance reader can be provided.

The present invention is not limited to the above embodiments, and various changes and improvements can be made without departing from the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a sectional view of a reader according to the present invention, FIG. 2 is a sectional view of a main part of the reader, and FIG. 3 is a sectional view of a conventional reader. 1,8 …… Glass substrate 2,9 …… Photoelectric conversion element array 3,11 …… Element selection IC chip 5,12 …… Board support member 6,10 …… Printed circuit board

Claims (1)

[Scope of utility model registration request] 1. A glass substrate for mounting a photoelectric conversion element and a signal processing circuit mounting substrate having a thickness smaller than that of the glass substrate are arranged on a substrate provided with a light source, and a document is fed onto the glass substrate. Is arranged on the signal processing circuit mounting board, and the light source irradiates the document sent by the roller through the glass substrate and the reflected light is received by the photoelectric conversion element. An element selection IC is arranged near the end, and the electrode of the IC and the electrode formed on the glass substrate for mounting the photoelectric conversion element are wire-bonded and the IC, both electrodes, and the bonding wire are covered with a resin layer. A reading device characterized by the above.