Active pixel array of CMOS image sensor

• US 7,817,198 B2
• Filed: 06/12/2006
• Issued: 10/19/2010
• Est. Priority Date: 08/02/2005
• Status: Expired due to Fees

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Ko, Joo Yul, Choi, Won Tae, Park, Deuk Hee, Kang, Shin Jae
• Primary Examiner(s): Chan; Jason
• Assistant Examiner(s): PRABHAKHER, PRITHAM DAVID
• Application Number:
  US11/423,666
• Publication Number:
  US 20070030370A1
• Time in Patent Office: 1,590 Days
• Field of Search: 348302-310, 348266-283, 257213-413
• US Class Current: 348/308
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/133 including elements passing panchromatic light, e.g. filters passing white light
• CPC Class Codes: H04N 25/70 SSIS architectures; Circuits associated therewith

Abstract

The present invention relates to an active pixel array of a CMOS image sensor. The active pixel array includes a pixel sensor array in which a pixel sensor which detects first and second light signals, of which the wavelengths are different from each other, among all wavelengths of light signals so as to generate current and voltage signals and a pixel sensor which detects a third light signal with a predetermined wavelength so as to generate a current or voltage signal are alternately arranged; and a color filter array that is formed on the pixel sensor array and in which a filter which transmits all wavelengths of light signals and a filter which transmits the third signal with a predetermined wavelength are alternately arranged.

Claims

1. An active pixel array of a CMOS image sensor comprising:

a pixel sensor array that includes a first pixel sensor configured to detect first and second light signals, of which the wavelengths are different from each other, among all wavelengths of light signals so as to generate current and voltage signals; and

a second pixel sensor configured to detect a third light signal with a predetermined wavelength so as to generate a current or voltage signal are alternately arranged; and

a color filter array that is formed on the pixel sensor array and in which a filter which transmits all wavelengths of light signals and a filter which transmits the third signal with a predetermined wavelength are alternately arranged;

wherein the color filter array is formed by repeatedly arranging a basic unit composed of first and third filters which transmit all the wavelengths of light signals and second and fourth filters which transmit the third light signal;

wherein;

the first pixel sensor comprises a first photoelectric conversion section, which detects the first and second light signals so as to generate a current signal, and first and second active pixel circuits which convert the generated current signal into a voltage signal to output;

the second pixel sensor comprises a second photoelectric conversion section, which detects the third signal so as to generate a current signal, and a third active pixel circuit configured to convert the generated current signal into a voltage signal to output;

a third pixel sensor that includes a third photoelectric conversion section configured to detect the first and second light signals so as to generate a current signal, and fourth and fifth active pixel circuits configured to convert the generated current signal into a voltage signal to output; and

a fourth pixel sensor that includes a fourth photoelectric conversion section configured to detect the third light signal so as to generate a current signal, and a sixth active pixel circuit configured to convert the generated current signal into a voltage signal to output, and

wherein the pixel sensor array is formed by repeatedly arranging a basic unit composed of the first to fourth pixel sensors.

2. The active pixel array of a CMOS image sensor according to claim 1,

wherein the first and second photoelectric conversion sections are respectively composed of first to third photodiodes and fourth to sixth photodiodes, which are double PN junction photodiodes, and the third and fourth photoelectric conversion sections are respectively composed of seventh to ninth photodiodes and tenth to twelfth photodiodes, which are double PN junction photodiodes.

3. The active pixel array of a CMOS image sensor according to claim 2,

wherein the first and seventh photodiodes detect the first light signal, the second, third, eighth, and ninth photodiodes detect the second light signal, and the fourth to sixth photodiodes and the tenth to twelfth photodiodes detect the third light signal.

4. The active pixel array of a CMOS image sensor according to claim 3,

wherein the anode terminal of the first photodiode is connected to a ground terminal, the cathode terminal thereof is connected to a first node, the anode terminals of the second and third photodiodes are connected to a ground terminal, and the cathode terminals thereof are connected to a second node.

5. The active pixel array of a CMOS image sensor according to claim 4,

wherein the anode terminal of the fourth photodiode is connected to a ground terminal, the cathode thereof is connected to a fifth node, the anode terminals of the fifth and sixth photodiodes are connected to a ground terminal, and the cathode terminals thereof are connected to a sixth node.

6. The active pixel array of a CMOS image sensor according to claim 5,

wherein the anode terminal of the seventh photodiode is connected to a ground terminal, the cathode thereof is connected to a ninth node, the anode terminals of the eighth and ninth photodiodes are connected to a ground terminal, and the cathode terminals thereof are connected to a tenth node.

7. The active pixel array of a CMOS image sensor according to claim 6,

wherein the anode terminal of the tenth photodiode is connected to a ground terminal, the cathode terminal thereof is connected to a thirteenth node, the anode terminals of the eleventh and twelfth photodiodes are connected to a ground terminal, and the cathode terminals thereof are connected to a fourteenth node.

8. The active pixel array of a CMOS image sensor according to claim 7,

wherein the first active pixel circuit includes:

a first switch that is connected to a third node, a power supply terminal, and the first node and changes the potential of the node connected to the first node by the signal charges stored in the first node so as to change the bias of the third node;

a second switch that is connected to the first switch and receives a first row signal so as to output the voltage signal converted by the first photodiode to a first column line; and

a third switch that is connected to the first node and a power supply terminal and receives a reset signal so as to reset the signal charges stored in the first node.

9. The active pixel array of a CMOS image sensor according to claim 8,

wherein the second active pixel circuit includes:

a fourth switch that is connected to a fourth node, a power supply terminal, and the second node and changes the potential of the node connected to the second node by the signal charges stored in the second node so as to change the bias of the fourth node;

a fifth switch that is connected to the fourth switch and receives a second row signal so as to output the voltage signal converted by the second and third photodiodes to the first column line; and

a sixth switch that is connected to the second node and a power supply terminal and receives a reset signal so as to reset the signal charges stored in the second node.

10. The active pixel array of a CMOS image sensor according to claim 9,

wherein the third active pixel circuit includes:

a seventh switch that is connected to an eighth node, a power supply terminal, and a seventh node and changes the potential of the node connected to the seventh node by the signal charges stored in the seventh node so as to change the bias of the eighth node;

an eighth switch that is connected to the seventh switch and receives the first row signal so as to output the voltage signal converted by the fourth to sixth photodiodes to a fourth column line; and

a ninth switch that is connected to the seventh node and a power supply terminal and receives a reset signal so as to reset the signal charges stored in the seventh node.

11. The active pixel array of a CMOS image sensor according to claim 10,

wherein the fourth active pixel circuit includes:

a tenth switch that is connected to an eleventh node, a power supply terminal, and the ninth node and changes the potential of the node connected to the ninth node by the signal charges stored in the ninth node so as to change the bias of the eleventh node;

an eleventh switch that is connected to the tenth switch and receives a third row signal so as to output the voltage signal converted by the seventh photodiode to a third column line; and

a twelfth switch that is connected to the ninth node and a power supply terminal and receives a reset signal so as to reset the signal charges stored in the ninth node.

12. The active pixel array of a CMOS image sensor according to claim 11,

wherein the fifth active pixel circuit includes:

a thirteenth switch that is connected to a twelfth node, a power supply terminal, and the tenth node and changes the potential of the node connected to the tenth node by the signal charges stored in the tenth node so as to change the bias of the twelfth node;

a fourteenth switch that is connected to the thirteenth switch and receives a fourth row signal so as to output the voltage signal converted by the eighth and ninth photodiodes to the third column line; and

a fifteenth switch that is connected to the tenth node and a power supply terminal and receives a reset signal so as to reset the signal charges stored in the tenth node.

13. The active pixel array of a CMOS image sensor according to claim 12,

wherein the sixth active pixel circuit includes:

a sixteenth switch that is connected to a sixteenth node, a power supply terminal, and a fifteenth node and changes the potential of the node connected to the fifteenth node by the signal charges stored in the fifteenth node so as to change the bias of the sixteenth node;

a seventeenth switch that is connected to the sixteenth switch and receives the third row signal so as to output the voltage signal converted by the tenth to twelfth photodiodes to the second column line; and

an eighteenth switch that is connected to the fifteenth node and a power supply terminal and receives a reset signal so as to reset the signal charges stored in the fifteenth node.

14. The active pixel array of a CMOS image sensor according to claim 13,

wherein the first to fourth row signals are sequentially applied.

15. The active pixel array of a CMOS image sensor according to claim 14 further including nineteenth to 24th switches that are respectively connected to the first, second, seventh, ninth, tenth, and fifteenth nodes of the first to sixth active pixel circuits and receive transfer signals so as to transfer the signal charges generated by the first to twelfth photodiodes.

16. The active pixel array of a CMOS image sensor according to claim 15, wherein the first to 24th switches are transistors.