Method and structure for accelerating image-sensing speed of a CCD image-sensing device
AssigneeAvision Inc.
InventorsMichael Chen, Ivan Wu
Life of this patent
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Abstract
The present invention discloses a method and structure for accelerating image-sensing speed in a CCD image-sensing device. According to the present invention, specific shift-control electrodes (G2j−1 and G2j) are biased to serve as a block unit. After the CCD image-sensing device serially shifts out the charge packets actually corresponding to the image of a sensed object, the CCD image-sensing device can repeat the operation for image sensing without first shifting out the remaining or undesired charge packets, thereby accelerating image-sensing speed.
Claims10
A CCD image-sensing device comprising:
- a plurality of image-sensing elements (P1˜Pn) for sensing light energy falling thereupon to generate a plurality of charge packets proportional to the light intensity;
- a CCD shift register having a plurality of register elements (SH1˜SH2n) for registering the charge packets, wherein the register elements (SH1˜SH2j−2;
- j<n) register only those charge packets that correspond to the image of a sensed object;
- and
- a plurality of shift-control electrodes (G1˜G2n), wherein the odd numbered shift-control electrodes (G1, G3, G5,˜G2j−5, G2j−3) are coupled to a first clock signal, and the even numbered shift-control electrodes (G2, G4, G6,˜G2j−4, G2j−2) are coupled to a second clock signal, thereby allowing the charge packets registered in register elements SH1˜SH2j−2 to be serially shifted out from the CCD shift register in response to the first and second clock signals;
- wherein shift-control electrodes G2j−1 and G2j are coupled to a first potential and a second potential, respectively, thereby creating a block unit composed of register elements SH2j−1 and SH2j which prevent or block the charge packets registered in register elements SH2j+1˜SH2n from being shifted into register elements SH1˜SH2j−2.
A method of accelerating image-sensing speed, appropriate for a CCD image-sensing device at least having a plurality of image-sensing elements (P1˜Pn) and a CCD shift register made up of a plurality of register elements (SH1˜SH2n) and a plurality of shift-control electrodes (G1˜G2n) corresponding to register elements (SH1˜SH2n), the method comprising the steps of:
- coupling shift-control electrodes G2j−1 and G2j to a first potential and a second potential respectively thereby creating a block unit composed of register elements SH2j−1 and SH2j;
- coupling the odd numbered shift-control electrodes (G1, G3, G5,˜G2j−5, G2j−3) to a first clock signal;
- coupling the even numbered shift-control electrodes (G2, G4, G6,˜G2j−4, G2j−2) to a second clock signal;
- having image-sensing elements (P1˜Pn) sense light reflected from an object falling thereupon and generating a plurality of charge packets proportional to light intensity;
- registering the charge packets in register elements SH1˜SH2n wherein register elements SH1˜SH2j−2 (j<n) register only the charge packets corresponding to the sensed object;
- serially shifting out the charge packets registered in register elements SH1˜SH2j−2 from the CCD shift register in response to the first and second clock signals wherein the charge packets registered in register elements SH2j+1˜SH2n are prevented from being shifted into register elements SH1˜SH2j−2 by the block unit thereby allowing the CCD image-sensing device to sense subsequent images without shifting out the charge packets registered in register elements SH2j+1˜SH2n;
- starting the next scanning operation whereby the image-sensing elements (P1˜Pn) sense again and generate a plurality of charge packets;
- and
- repeating the operations of registering and shifting out charge packets.
Dependencies are inferred from the claim text.