JPH0338963A - Image sensor - Google Patents

Abstract

PURPOSE:To avoid cross of optical information between optical fibers and to read a picture with high resolution by providing a light absorbing body to an outer surface of a clad being a component of an optical fiber. CONSTITUTION:A light absorbing body 23 with a prescribed thickness is formed to an outer surface of a clad 22 of an optical fiber and lots of optical fibers are inserted between two glass bases 17, the heat of nearly a melting point of the glass is applied to the fibers while pressing the fibers from both sides to make an optical fiber array 16. Since the light absorbing body 23 is provided to the outer surface of the optical fibers constituting the optical fiber array 16 in this way, when light information from an original 10 is led to a photodetector 13 by using the optical fiber array 16, the cross of the optical information between the optical fibers is prevented by the light absorption by the light absorbing body 23 on the outer surface of each optical fiber and then the resolution of picture reading is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image sensor that detects an image of a document or the like and obtains an image signal.

2. Description of the Related Art In an image sensor using a conventional optical fiber array, as shown in FIG. The optical information of a document 4 placed close to the other end of the optical core array 3 is guided to the light receiving element 2 using the optical fiber array 3 and converted into an image signal.

Problems to be Solved by the Invention However, in such an image sensor, optical information from the document 4 intersects (crosstalk) between the optical fibers composing the optical core array 3, and the resolution of the image reading system decreases. was low. Therefore, an object of the present invention is to improve the resolution of image reading.

Means for Solving the Problems In order to achieve this object, the image sensor of the present invention is one in which a light absorber is provided on the outer surface of each optical fiber constituting an optical fiber array.

Effects According to the present invention, when optical information from a document is guided to a light receiving element using an optical fiber array, crosstalk of optical information between optical fibers is prevented by the light absorber on the outer surface of each optical fiber. is prevented by light absorption by, thus making it possible to guide in a one-to-one correspondence, ii! ii) The resolution of image reading is improved.

Example An embodiment of the present invention will be described below with reference to the drawings.

1 and 3 are a front sectional view and a side sectional view of an image sensor according to an embodiment of the present invention.

11 is a coating resin, 12 is an image sensor chip, 13 is a plurality of light receiving elements provided on the image sensor chip 12, 14 is an electrode of the image sensor chip 12,
16, a circuit conductor layer formed on the glass substrate 17;
6 is an optical fiber array sandwiched between glass substrates 17;
18 is a blackish film formed on the upper and lower surfaces of the glass substrate 37; 19 is a light source that illuminates the original 10; Also second
The figure is a plan view of the optical fiber array 16, and each optical fiber is composed of a core at the center, a cladding 22 on the outer surface of the core, and a light absorber provided on the outer surface of the cladding 22.

Next, detailed parts of the image sensor configured as above will be explained in more detail.

As shown in FIG. 2, a light absorber 2 with a thickness of 2 to 311 m is attached to the outer surface of the cladding 22 of an optical fiber with a diameter of approximately 25 μm.
As shown in FIG. 3, the optical fiber array 16 is sandwiched between two glass substrates 37, and heated to about the melting point of the glass while applying pressure from both sides. Create. Next, a black film 18 is formed on both sides of the glass substrate 7 by screen printing in areas other than the areas through which illumination light passes. Furthermore, this optical fiber array 16
Then, a circuit conductor layer 16 is formed on one end surface of the glass substrate 17 using a noble metal such as Au or Ag-Pt by a screen printing method or a thin film forming method and a 7-Otorino method. Furthermore, an image sensor chip 12 is formed in which a large number of light receiving elements 13 having a size of 60 to 100 μm square are formed in parallel at regular intervals (e2.6 pm or 125 μI!I).
The image sensor chip 12 is bonded face-down so that it is in close contact with one end of the optical fiber array 16.
The circuit conductor layer 16 is mounted so that the electrode 14 is connected to a predetermined position of the circuit conductor layer 16. Furthermore, in order to protect this image sensor chip 12, a coating resin 11 such as silicone resin is added.
Coat with. An image sensor is manufactured in the manner described above.

Using this image sensor, the original 10 is brought into close contact with the other end of the optical fiber array 1e, and the light source (LED array) 1
9 to the black film 18 on the upper surface side of the glass substrate 17.
The glass substrate 17
The original 10 is illuminated through the optical fiber by passing through the light absorber 23 of the optical fiber. At this time, light absorber 2
Regarding 3, increase the light absorption rate to 8 so that some light can pass through.
It is set to around 0%.

Optical information from the original 10 is guided to the light-receiving element 13 in a one-to-one correspondence, without crosstalk, by a large number of optical fibers provided with light absorbers 23. Further, unnecessary light from the outside is blocked by the black film 18 by 100 times.

In this way, high resolution (MTF value of 4ep/M and about 8
0) made it possible to read images.

Effects of the Invention As described above, according to the present invention, since a light absorber is provided on the outer surface of the cladding constituting the optical fiber, there is no crossing of optical information between the optical fibers, and as a result, it is possible to obtain images with high resolution. We were able to create a reading image sensor.

[Brief explanation of drawings]

Fig. 1 is a front cross-sectional view of an image sensor according to an embodiment of the present invention, Fig. 2 is a top view of the same fiber array, Fig. 3 is a side sectional view of the same image sensor, and Fig. 4 is an image of a conventional example. FIG. 3 is a front cross-sectional view of the sensor. 10... Original, 11... Coating resin, 12... Image sensor chip, 13...
. . . Light receiving element, 14 . . . Electrode of image sensor chip, 15. Pa. Circuit conductor layer, 16... Optical fiber array, 17.
...Glass substrate, 18...Black film, 19.
...°light source.

Claims (3)

[Claims] (1) An optical fiber array formed by arranging a plurality of optical fibers, and a plurality of photodetecting elements provided at one end of the optical fiber array, the optical fiber having a central core and a core of the optical fiber array. An image sensor consisting of a cladding provided on the outer surface of the cladding and a light absorber provided on the outer surface of the cladding. (2) A claim in which a light source is provided at one end of the optical fiber array, and the light from the light source passes through a light absorber, enters the optical fiber array, and is guided to the other end of the optical fiber array. The image sensor according to 1. (3) The image sensor according to claim 1 or 2, wherein a wall surface is provided on the other end side of the optical fiber array in a direction substantially perpendicular to this end portion, and a blackish film is provided on this wall surface.