Contact-type image sensor

Abstract

The invention discloses a contact-type image sensor. The contact-type image sensor is provided with a preset scanning surface corresponding to a to-be-scanned surface of a manuscript. The contact-typeimage sensor comprises a time sequence generation circuit which is used for generating a light source control signal LRDT and a line scanning control signal TRIG1; a light source which is used for irradiating the manuscript; a lens which is used for collecting the reflected light emitted by the light source and reflected by the manuscript and emitting the reflected light to a photoelectric conversion chip; the photoelectric conversion chip which is used for converting the received optical signal into an electric signal; and a data processing unit which is used for receiving and processing theelectric signal output by the photoelectric conversion chip according to a trigger pulse TRIG sent by an encoder for transmitting an object to be detected. The photosensitive signals output by the photoelectric conversion chip are the same, so that the output stability, the dynamic range and the sensitivity of the image sensor are guaranteed.

Description

technical field [0001] The invention belongs to the technical field of image sensors, and in particular relates to a contact image sensor. Background technique [0002] In the prior art, the block diagram of the existing contact image sensor is as follows: figure 1 As shown, it is composed of a light source, a lens, a photoelectric conversion chip, a data processing unit, and a data output part. Image sensor scanning In order to match the moving speed of the external object to be detected, the trigger pulse TRIG is sent by the motor or encoder that transmits the object to be detected, and the light emitted by the light source shines on the original, and the image, text, etc. on the original generate reflected light or transmitted light The reflected light or transmitted light passes through the lens and irradiates the photoelectric conversion chip. The photoelectric conversion chip converts the received optical signal into an electrical signal, and after being processed by ...

AI Technical Summary

Problems solved by technology

[0006] From the above, the photosensitive output and dark voltage of each row are different and random, resulting in the inability to correct the image sensor, which will seriously affect the sensitivity of the photoelectric conversion chip, the dynamic range and the output variation of each row, affecting image recognition; extreme cases If the speed of transmitting the object to be detected is too slow and the line cycle is too long, the dark voltage will be too large, and the dark voltage will reach the limit value, which will make the photoelectric conversion chip in a saturated state and cannot receive light signals at all; therefore, it is urgent to develop a new contact image sensor

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