Solid-state image sensing device and image sensing device including the solid-state image sensing device

• US 20060072025A1
• Filed: 09/27/2005
• Published: 04/06/2006
• Est. Priority Date: 10/05/2004
• Status: Active Grant

• Current Assignee: Sony Semiconductor Solutions Corporation (Sony Group Corp.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Sato, Kazuchika, Kakumoto, Tomokazu, Tanaka, Yoshihiro, Kusuda, Masayuki, Yano, So
• Granted Patent: US 7,839,442 B2
• Time in Patent Office: Days
• US Class Current: 348/308
• CPC Class Codes: H04N 25/672 between adjacent sensors or output registers for reading a single image

Abstract

An object of the present invention is to provide a solid-state image sensing device configured to change a bias voltage given to the photoelectric converting section at the time of resetting so that an operative condition of the photoelectric converting section after the resetting can be maintained a constant condition regardless of an amount of the incident light.

To achieve the object, an MOS transistor T5 is provided. The drain of the MOS transistor T5 is connected with a gate and a drain of an MOS transistor T2 and the source of the MOS transistor T5 configured to be applied a DC voltage VRS. Here, a signal φ V is given, an MOS transistor T4 is turned on, and image data is output. A signal φ RS is given and the MOS transistor T5 is turned on. As a result, a gate voltage Vg of the MOS transistor T2 is maintained as a constant voltage value. Then, a reset operation for pixels is stared.

Claims

1. A solid-state image sensing device having a pixel including a photoelectric converting element for producing an electric signal according to an amount of light projected thereto, a first transistor for connecting with the photoelectric converting element and generating an electric signal according to photoelectric charge from the photoelectric converting element, and an output unit for outputting the electric signal from the first transistor,

wherein the pixel includes an reset voltage supplying unit for supplying a predetermined voltage to a connecting part between the photoelectric converting element and the first transistor in a predetermined timing at a time of resetting.

2. A solid-state image sensing device according to claim 1,

wherein the reset voltage supplying unit includes a first electrode configured to be applied a predetermined voltage and a second electrode configured to be connected with the connecting part between the photoelectric converting element and the first transistor, and

wherein the reset voltage supplying unit is a second transistor configured to be turned on and off in the predetermined timing.

3. A solid-state image sensing device according to claim 1,

wherein the predetermined timing is after an image data reading operation in which an electric data to be used as screen image data obtained by an image sensing operation performed by the photoelectric converting element and the first transistor is output from the output unit, and

wherein the predetermined voltage is a voltage value which is produced in the connection part between the photoelectric converting element and the first transistor when light having a higher brightness value than a photographable brightness range is emitted to the photoelectric converting element.

4. A solid-state image sensing device according to claim 1,

wherein the pixel includes a switch for electrically connecting and disconnecting the photoelectric converting element and the first transistor,

wherein when the pixel performs an image sensing operation, the switch is turned on to connect the photoelectric converting element and the first transistor, and

wherein when the pixel performs a reset operation, the switch is turned off to disconnect the photoelectric converting element and the first transistor to reset an operative condition of the first transistor, and the switch is turned on to connect the photoelectric converting element and the first transistor to reset remained electric charge in the photoelectric converting element.

5. A solid-state image sensing device according to claim 4,

wherein the predetermined timing is just before the remained electric charge in the photoelectric converting element is reset, and

wherein the predetermined voltage is a voltage value which is created at the connecting part between the photoelectric converting element and the first transistor according to the remained electric charge created in the photoelectric converting element when light having a higher brightness value than a photographable brightness range is emitted to the photoelectric converting element.

6. An image sensing device including a solid-state image sensing device for outputting an electric signal obtained in an image sensing operation as image data and outputting an electric signal obtained after a reset operation as correcting data, and a subtracter for outputting a value obtained by subtracting the image data and the correcting data from the solid-state image sensing device,

wherein the solid-state image sensing device is the solid-state image sensing device claimed in claim 1.

7. An image sensing device including a solid-state image sensing device for outputting an electric signal obtained in an image sensing operation as image data and outputting an electric signal obtained after resetting as correcting data, a subtracter for outputting image signal obtained by subtracting the image data and the correcting data from the solid-state image sensing device, and a signal processing unit for performing signal processing on the image signal from the subtracter, comprising:

the solid-state image sensing device which is the solid-state image sensing device claimed in claim 1,

a comparator for comparing the correcting data output from the solid-state image sensing device with a reference value, and

a determining unit for determining whether or not to select the image signal from the subtracter as image data for signal processing according to a comparison result in the comparator.

8. An image sensing device according to claim 7, wherein, in a case that the determining unit confirms that a value of the correcting data is in a brightness range which is substantially changed from a brightness value according to the comparison result in the comparator, not an image signal from the subtracter but an image signal set in a value based on a highest brightness value is selected as an image signal for the signal processing.

9. An image sensing device according to claim 7, comprising:

a memory for previously storing the correcting data,

wherein, in a case that the determining unit confirms that a value of the correcting data is in a brightness range which is substantially changed from a brightness value according to the comparison result in the comparator, not an image signal from the subtracter but an image signal obtained by subtracting the image data output from the solid-state image sensing device and the correcting data stored in the memory is selected as an image signal for the signal processing.

10. An image sensing device according to claim 9, wherein the correcting data stored in the memory is a correcting data stored in a condition that a value of the correcting data is in a brightness range which is approximately constant to brightness value, according to the comparison result in the comparator.

11. A method of resetting a solid-state image sensing device having a pixel including a photoelectric converting element for producing an electric signal according to an amount of light projected thereto, a first transistor for connecting with the photoelectric converting element and generating an electric signal according to photoelectric charge from the photoelectric converting element, and an output unit for outputting the electric signal from the first transistor, the method comprising the steps of:

performing an image data reading operation in which an electric data to be used as screen image data obtained by an image sensing operation performed by the photoelectric converting element and the first transistor is output from the output unit; and

supplying a predetermined voltage to a connecting part between the photoelectric converting element and the first transistor after the image data reading operation at a time of resetting.

12. A method according to claim 11,

wherein the predetermined voltage is a voltage value which is produced in the connection part between the photoelectric converting element and the first transistor when light having a higher brightness value than a photographable brightness range is emitted to the photoelectric converting element.

13. A method according to claim 11,

wherein the pixel includes a switch for electrically connecting and disconnecting the photoelectric converting element and the first transistor,

wherein when the pixel performs an image sensing operation, the switch is turned on to connect the photoelectric converting element and the first transistor, and

wherein when the pixel performs a reset operation, the switch is turned off to disconnect the photoelectric converting element and the first transistor to reset an operative condition of the first transistor, and the switch is turned on to connect the photoelectric converting element and the first transistor to reset remained electric charge in the photoelectric converting element.

14. A method according to claim 13,

wherein the time of resetting is just before the remained electric charge in the photoelectric converting element is reset, and

wherein the predetermined voltage is a voltage value which is created at the connecting part between the photoelectric converting element and the first transistor according to the remained electric charge created in the photoelectric converting element when light having a higher brightness value than a photographable brightness range is emitted to the photoelectric converting element.