Low power image sensor adjusting reference voltage automatically and optical pointing device comprising the same

Abstract

A low power image sensor sensing light from an object and outputting an image signal includes: an image sensing unit which senses light from an object, converts the light into an electric signal, and outputs the electric signal; a comparing unit which receives an electric signal from the image sensor, compares a voltage level of the electric signal with a reference voltage, and outputs an image signal as an 1bit signal per pixel; and an effective image adjuster which compares bit value distribution of an image signal output from the comparator with a preset effective range, and adjusts the effective image to output an effective image. Further, an optical pointing device includes: an image sensor which senses light from an object and outputs an image signal; and a motion computing unit which receives the image signal and compares before and after images to calculate a motion vector, wherein the motion computing unit includes: a temporary storage unit to temporarily store image data output from the image sensor; a comparator to compare the image data output from the image sensor with the image data stored in the temporary storage unit; a direction selector; and a controller.

Description

technical field [0001] The present invention relates to a low-power image sensor that adjusts a reference voltage and an optical click device with the sensor, in particular to a low-power image sensor that automatically adjusts a reference voltage to output a reliable 1-bit image signal that is suitable for motion calculation and can be used in the image sensor output An optical click device that calculates before and after the image to effectively predict movement or tap. Background technique [0002] The present invention relates to optical pointing devices and low power image sensors used therein. Usually, an optical mouse or a finger mouse senses the mouse pad or fingerprint and calculates the direction and speed of the movement to perform the clicking function. [0003] Existing optical or finger mice include image signal processing chips such as figure 1 shown. [0004] figure 1 Image sensors that are shown to sense image information such as mouse pads or fingerpri...

AI Technical Summary

Problems solved by technology

However, a preprocessor with complex DSP functions requires a large chip area and consumes a lot of power

In particular, the small and smart mobile devices currently in use need to be reduced in size, consume less power and process images faster, but existing image sensors cannot meet these requirements

[0009] In addition, in

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