JPS59139669A - Close contact type line sensor - Google Patents

Abstract

PURPOSE:To eliminate the color aberration as well as to enable to form the titled line sensor into small size and light-weighted structure by a method wherein a fiber plate whereon a number of fibers having no photo absorbing material is flocked in a closely contacted form between the transmitting manuscript and the photo detecting part. CONSTITUTION:The light L irradiated from a light source 1 passes through a photo detecting substrate 2, penetrates into a fiber plate 4, and is made incident to the core part 5 of the film 5 and the clad part 5 at approximate angle of 30 deg.. Said light L is penetrated into the fiber 5 turning away the critical angle of the fiber plate 4 and the clad part 5, and the transmitting manuscript is illuminated by the light L. The reflected light L' which read out the transmitting manuscript reaches a photo detecting part 3 while repeating a total reflection between the core part 5 and the clad part 5, and reads the information of the transmitting manuscript 6. On the photo detecting part 3, a reflected light L' of 2-3 times increased luminance can be obtained using the light 1 having the same illuminance as the conventional one.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a contact type line sensor used in facsimiles and the like, and in particular to a light guide structure suitable for reducing weight and reducing chromatic aberration. It is related to.

[Prior art]

Conventional close-contact line sensors emit light from a light source such as an LED or a fluorescent display tube onto the height of the transmission source, and the reflected light from the original is collected using a SELFOC lens (commercial product). A configuration was used in which light was guided to a photodetector through a rod array lens such as the one shown in Japanese.

However, with such a configuration, since a rod array lens is used as a light guiding means from the transmission document to the photodetection section, chromatic aberration remains and it cannot be used as a color sensor. In addition, since the focal length of the rod array lens is usually in the range of 5 to 10 degrees, it is necessary to place the transmission document and the light detection unit at the upper and lower parts of the rod array lens, respectively, at positions 5 to 10 degrees apart. Therefore, there was a drawback that the device casing became large.

[Purpose of the invention]

Therefore, the present invention has been made in view of the above-mentioned conventional drawbacks, and its object is to provide a contact type line sensor that is free from chromatic aberration and that can be made smaller and lighter.

[Summary of the invention]

In order to achieve such an object, the present invention places a fiber plate L7 in close contact with a large number of core ingots without light absorbers between the transmission original and the photodetector, and Light from a light source is guided from the side.

[Embodiments of the invention]

Next, embodiments of the present invention will be described in detail using the drawings.

FIG. 1 is a cross-sectional configuration diagram of essential parts showing an example of a contact type line sensor according to the present invention. In the figure, 1 is a light source consisting of a fluorescent display tube, LED, or fluorescent lamp, and 2 is a photodetection board on which a photodetection section 3 made of an amorphous silicon film is mounted. The rear side and the light source 1 side are shielded from light by a light absorber (not shown). Reference numeral 4 denotes a fiber plate in which a large number of fibers 5 each having a diameter of approximately 20 μm are closely planted in a portion facing the photodetection unit 3 and are placed in close contact with the photodetection board 2;
As shown in the enlarged sectional view in the figure, there is a core part 5a with n=1.6 at the center of the trap and a clad part 5b with n=1.3 around it.
It is composed of: Reference numeral 6 denotes a transmission document that is moved in the direction of arrow A while coming into contact with this fiber plate 4 surface.

In such a configuration, the light emitted from the light source 1 passes through the photodetection board 2 and enters the fiber plate 4, and as shown in FIG. When the light enters the cladding portion 5b at an angle of approximately 30° or more, the light deviates from the critical angle between the fiber plate 4 and the cladding portion 5b and enters the fiber 5, and the transmitted original 6 is illuminated by this light. . Then, the reflected light L' that has read the transmitted original 6 reaches the photodetector 3 while repeating total reflection between the core part 5a and the cladding part 5b, and can read the information on the transmitted original 6. .

According to such a configuration, only the core portion 5a and the cladding portion 5b of the core portion, cladding portion, and absorber portion used in a normal fiber plate are placed between the photodetecting unit 3 and the transmission document 6. A fiber plate 4 made up of a large number of fibers 5 having the configuration shown in FIG. By reading out ', the light detection unit 3 can receive reflected light whose brightness is 2 to 3 times higher using the light source 11'' with the same illuminance as the conventional one, and a color transmitted image with no chromatic aberration can be obtained. is obtained.

〔Effect of the invention〕

As explained above, according to the present invention, a fiber plate without a light absorber is used between the transmission document and the photodetector, without using a rod array lens that increases the size of the device housing due to its short focal length. By closely arranging them, the sensor device can be made smaller and lighter, and a color transmitted image without chromatic aberration can be obtained, which is an extremely excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a close-contact type line sensor according to the present invention, showing a cross-section of the main part shown in FIG. 2, FIG. FIG. 3 is an enlarged cross-sectional view of a main part for explaining the operation of the line sensor. DESCRIPTION OF SYMBOLS 1...Light source, 2...Photodetection board, 3...Photodetection part, 4...Fiber grade, 5...-1 fiber, 5a...Core g (S, 5b...Clad part, 6...Sent manuscript.

Claims (1)

[Claims] In a contact type line sensor that reads information on a transmission document by irradiating a YT source light onto the transmission document and guiding the reflected light to a light detection section, a core section is provided between the transmission document and the light detection section. A close-contact type line sensor characterized in that a core ingot plate consisting of a cladding portion and a core ingot plate is disposed in close contact with each other, and a light source light is irradiated from a side surface of the cladding portion.