Photo-sensor device and image scanning system employing the same

• US 4,293,877 A
• Filed: 03/30/1979
• Issued: 10/06/1981
• Est. Priority Date: 03/31/1978
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Niwa, Yukichi, Tsunekawa, Tokuichi, Hosoe, Kazuya, Masunaga, Makoto, Asano, Noriyuki, Owada, Mitsutoshi
• Primary Examiner(s): Martin, John C.
• Application Number:
  US06/025,542
• Time in Patent Office: 921 Days
• Field of Search: 358/212, 358/213, 358/221, 358/167, 358/113, 358/280, 358/293, 358/294, 358/285, 358/3, 307/311, 307/310, 307/221 D, 250/211 J, 250/578, 250/332, 250/201, 250/208, 250/209, 354/23 R, 354/25, 357/30, 357/28, 357/24, 328/151, 330/289, 356/1, 356/4
• US Class Current: 348/316
• CPC Class Codes: G02B 7/36 using image sharpness techniques , e.g. image processing techniques for generating autofocus signals image data processing per se G06T; in cameras having a solid state image sensor H04N23/67

Abstract

A photo-sensor device comprises a light receiving part composed of a plurality of photo-sensor elements for converting photosignals into electrical signals. A portion of the light receiving part is shielded by light shielding means so that in reading out the output from the device, there can be obtained also a signal of dark current information from the shielded photo-sensor elements.

Claims

1. A radiation sensing device comprising:

(a) radiation sensing means having a plurality of radiation sensitive elements, each for providing an electrical signal corresponding to received radiation, said plurality of radiation sensitive elements in said radiation sensing means being arranged in array;

(b) optically opaque means for shielding a portion of said radiation sensing means so that an electrical signal indicative of a dark current is provided by one or more radiation sensitive elements shielded by said opaque means, said optically opaque means shielding at least one radiation sensitive element located at or near the end of said array;

(c) time-seriation output means for emitting in seriatim electrical signals provided by said radiation sensitive elements in order of arrangement of said elements in the array;

(d) means for receiving a bias voltage to be supplied to said device; and

(e) means electrically coupled with said bias voltage receiving means so as to provide an electrical signal informing of internal voltage variation in said device relative to variation of said bias voltage,

wherein said optically opaque means is disposed to shield one or more such radiation sensitive elements the electrical signals of which are to be put out by said time-seriation output means relatively early in the output sequence, and said radiation sensing means, said time-seriation output means, said bias voltage receiving means and said internal voltage variation information providing means are formed on or in the same semiconductive substrate.

2. A radiation sensing device according to claim 1, wherein said internal voltage variation information providing means includes a field effect transistor having source, gate and drain electrodes for producing the electrical signal information of internal voltage variation through the source electrode wherein the drain electrode is electrically coupled to said bias voltage receiving means, and the gate electrode is constructed such that a potential variable in accordance with the internal voltage variation in the sensing device is applied to the gate electrode.

3. An image scanning system comprising:

(A) a radiation sensing device arranged to receive an image, said device having;

(a) radiation sensitive means for providing electrical signals corresponding to received radiations;

(b) means for providing an electrical signal indicative of a dark current of the sensing device;

(c) means for receiving a bias voltage to be supplied to said device; and

(d) means electrically coupled with said bias voltage receiving means so as to provide an electrical signal informing of internal voltage variation in said device relative to variation of said bias voltage,

wherein said internal voltage variation information providing means includes a field effect transistor having source, gate and drain electrode for producing the electrical signal information of internal voltage variation through the source electrode wherein the drain electrode is electrically coupled to said bias voltage receiving means, and the gate electrode is constructed such that a potential variable in accordance with the internal voltage variation in the sensing device is applied to the gate electrode; and

(B) circuit means electrically coupled to said sensing device for compensating for the electrical signals provided by said radiation sensitive means with the electrical signal provided by said internal voltage variation information providing means and the dark current signal provided by said dark current signal providing means.

4. An image scanning system according to claim 3, wherein said circuit means includes:

a first circuit for compensating for the electrical signals provided by said radiation sensitive means with the electrical signal provided by said internal voltage variation information providing means; and

a second circuit for compensating for the electrical signals provided by said radiation sensitive means with the dark current signal provided by said dark current signal providing means.

5. An image scanning system according to claim 3, wherein said circuit means includes;

a first circuit for compensating for the electrical signals provided by said radiation sensitive means and the dark current signal provided by said dark current signal providing means with the electrical signal provided by said internal voltage variation information providing means; and

a second circuit for compensating for the electrical signals compensated by said first circuit and related to the radiation sensitive means with the dark current signal compensated by the first circuit and related to the dark current signal providing means.

6. An image scanning system comprising:

(a) a radiation sensing device arranged to receive an image, said sensing device including;

(i) An array of a plurality of radiation sensitive elements, each for providing an electrical signal indicative of received portion of said image;

(ii) Optically opaque means for shielding a portion of said array so that an electrical signal indicative of a dark current is provided by one or more radiation sensitive elements shielded by said opaque means;

(iii) time-seriation output means for emitting in seriatim electrical signals provided by said radiation sensitive elements in order of arrangement of said elements in the array; and

(iv) output terminal means for leading out the electrical signals provided by said radiation sensitive elements to the exterior of said sensing device; and

(b) means coupled to said output terminal means of said sensing device to subtract the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque means from the electrical signals provided by unshielded radiation sensitive elements,

wherein said array of radiation sensitive elements, said time-seriation output means and at least a portion of said subtract means are formed on or in the same semi-conductive substrate,

said sensing device further comprising;

means for receiving a bias voltage to be supplied to the sensing device;

detection means electrically coupled to said bias voltage receiving means for detecting internal voltage variation in the sensing device relative to variation of said bias voltage and producing a detection signal to indicate the variation of the internal voltage; and

second output terminal means for leading out the detection signal provided by said detection means to the exterior of said sensing device;

and wherein said image scanning system further comprises;

means coupled to both of said output terminal means of the sensing device to compensate for the electrical signals provided by the radiation sensitive elements with the detection signal provided by said detection means,

wherein said bias voltage receiving means, said detection means and at least a portion of said compensation means are formed on or in said semi-conductive substrate.

7. An image scanning system according to claim 6, wherein said subtracting means is coupled to said compensation means to receive the compensated electrical signals by said compensation means.

8. An image scanning system according to claim 6, wherein said subtracting means includes:

a circuit coupled to the output terminal means of said sensing device to sample and hold the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque means; and

a circuit coupled to the output terminal means and said sampling and holding circuit to subtract the electrical signal sampled and held by said sampling and holding circuit from the electrical signals provided by the unshielded radiation sensitive elements,

wherein at least a portion of said sampling and holding circuit and at least a portion of said subtract circuit are formed on or in said semi-conductive substrate.

9. An image scanning system according to claim 8, which further comprises control means coupled to said sampling and holding circuit for controlling said circuit so that only the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque may be sampled and held by said sampling and holding circuit.

10. An image scanning system according to claim 9, which further comprises driving means coupled to said sensing device for supplying timing signals to said device to drive the same and wherein said control means is coupled to said driving means and controls said sampling and holding circuit relying upon the timing signals coming from said driving means.

11. An image scanning system according to claim 6, wherein said detection means includes a field effect transistor having source, gate and drain electrodes for producing the detection signal indicative of the internal voltage variation through the source electrode wherein the drain electrode is electrically coupled to said bias voltage receiving means, and the gate electrode is constructed such that a potential variable in accordance with the internal voltage variation in the sensing device is applied to the gate electrode.

12. An image scanning system comprising:

(a) a radiation sensing device arranged to receive an image, said sensing device including;

(i) an array of a plurality of radiation sensitive elements, each for providing an electrical signal indicative of received portion of said image;

(ii) optically opaque means for shielding a portion of said array so that an electrical signal indicative of a dark current is provided by one or more radiation sensitive elements shielded by said opaque means;

(iii) time-seriation output means for emitting in seriatim electrical signals provided by said radiation sensitive elements in order of arrangement of said elements in the array; and

(iv) output terminal means for leading out the electrical signals provided by said radiation sensitive elements to the exterior of said sensing device; and

(b) means coupled to said output terminal means of said sensing device to subtract the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque means from the electrical signals provided by unshielded radiation sensitive elements, said subtracting means including;

a circuit coupled to the output terminal means of said sensing device to sample and hold the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque means; and

a circuit coupled to the output terminal means and said sampling and holding circuit to subtract the electrical signal sampled and held by said sampling and holding circuit from the electrical signals provided by the unshielded radiation sensitive elements,

wherein at least a portion of said sampling and holding circuit and at least a portion of said subtract circuit are formed on or in said-semi-conductive substrate, and

wherein said array of radiation sensitive elements, said time-seriation output means at least a portion of said subtract means are formed on or in the same semi-conductive substrate, said sampling and holding circuit including;

a capacitor adapted for holding an electrical signal corresponding to the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque means;

a charging circuit coupled to said capacitor for charging the capacitor with a constant current;

a charge control circuit for controlling the charging of said capacitor with said constant current on the basis of the electrical signal provided by said one or more radiation sensitive elements shielded by the opaque means, said charge control circuit being coupled to said output terminal means and to said charging circuit; and

an output circuit coupled to said capacitor for putting out the electrical signal held by the capacitor as the electrical signal provided by said one or more radiation sensitive elements shielded by the opaque means;

said subtract circuit being coupled to said output circuit and subtract the electrical signal provided through the output circuit from the electrical signals provided by the unshielded radiation sensitive elements.

13. An image scanning system comprising:

(a) a radiation sensing device arranged to receive an image, said sensing device including;

(i) an array of a plurality of radiation sensitive elements, each for providing an electrical signal indicative of received portion of said image;

(ii) optically opaque means for shielding a portion of said array so that an electrical signal indicative of a dark current is provided by one or more radiation sensitive elements shielded by said opaque means;

(iii) time-seriation output means for emitting in seriatim electrical signals provided by said radiation sensitive elements in order of arrangement of said elements in the array; and

(iv) output terminal means for leading out the electrical signals provided by said radiation sensitive elements to the exterior of said sensing device; and

(b) means coupled to said output terminal means of said sensing device for subtracting the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque means from the electrical signals provided by unshielded radiation sensitive elements,

wherein, said subtracting means includes;

a circuit coupled to the output terminal means of said sensing device to sample and hold the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque means; and

a circuit coupled to the output terminal means and said sampling and holding circuit to subtract the electrical signal sampled and held by said sampling and holding circuit from the electrical signals provided by the unshielded radiation sensitive elements, and

wherein said sampling and holding circuit includes;

a capacitor adapted for holding an electrical signal corresponding to the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque means;

a charging circuit coupled to said capacitor for charging the capacitor with a constant current;

a charge control circuit for controlling the charging of said capacitor with said constant current on the basis of the electrical signal provided by said one or more radiation sensitive elements shielded by the opaque means, said charge control circuit being coupled to said output terminal means and to said charging circuit; and

an output circuit coupled to said capacitor for putting out the electrical signal held by the capacitor as the electrical signal provided by said one or more radiation sensitive elements shielded by the opaque means;

said subtract circuit being coupled to said output circuit and subtract the electrical signal provided through the output circuit from the electrical signals provided by the unshielded radiation sensitive elements;

means for receiving a bias voltage to be supplied to the sensing device;

detection means electrically coupled to said bias voltage receiving means for detecting internal voltage variation in the sensing device relative to variation of said bias voltage and producing a detection signal to indicate the variation of the internal voltage; and

second output terminal means for leading out the detection signal provided by said detection means to the exterior of said sensing device;

and wherein said image scanning system further comprises;

means coupled to both of said output terminal means of the sensing device to compensate for the electrical signals provided by the radiation sensitive elements with the detection signal provided by said detection means, and

wherein said detection means includes;

a field effect transistor having source, gate and drain electrodes for producing the detection signal indicative of the internal voltage variation through the source electrode wherein the drain electrode is electrically coupled to said bias voltage receiving means, and the gate electrode is constructed such that a potential variable in accordance with the internal voltage variation in the sensing device is applied to the gate electrode.

14. An image scanning system according to claim 13 which further comprises control means coupled to said sampling and holding circuit for controlling said circuit so that only the electrical signal provided by said one or more radiation sensitive elements shielded by said opaque means may be sampled and held by said sampling and holding circuit.

15. An image scanning system according to claim 14, which further comprises driving means coupled to said sensing device for supplying timing signals to said device to drive the same and wherein said control means is coupled to said driving means and controls said sampling and holding circuit relying upon the timing signals coming from said driving means.

16. An image scanning system according to claim 13 wherein said subtracting means is coupled to said compensation means to receive the compensated electrical signals by said compensation means.

17. A radiation sensing device comprising:

(a) radiation sensitive means for providing electrical signals corresponding to received radiations;

(b) means for providing an electrical signal indicative of a dark current of the sensing device;

(c) means for receiving a bias voltage to be supplied to said device; and

(d) means electrically coupled with said bias voltage receiving means so as to provide an electrical signal informing of internal voltage variation in said device relative to variation of said bias voltage,

wherein said radiation sensitive means, said dark current signal providing means, said bias voltage receiving means and said internal voltage variation information providing means are formed on or in the same semi-conductive substrate.

18. A radiation sensing device according to claim 17, wherein said internal voltage variation information providing means includes a field effect transistor having source, gate and drain electrode for producing the electrical signal information of internal voltage variation through the source electrode wherein the drain electrode is electrically coupled to said bias voltage receiving means, and the gate electrode is constructed such that a potential variable in accordance with the internal voltage variation in the sensing device is applied to the gate electrode.

19. A radiation sensing device comprising:

(a) radiation sensitive means for providing electrical signals corresponding to received radiations;

(b) means for providing an electrical signal indicative of a dark current of the sensing device;

(c) means for receiving a bias voltage to be supplied to said device; and

(d) means electrically coupled with said bias voltage receiving means so as to provide an electrical signal informing of internal voltage variation in said device relative to variation of said bias voltage,

wherein said internal voltage variation information providing means includes a field effect transistor having source, gate and drain electrode for producing the electrical signal information of internal voltage variation through the source electrode wherein the drain electrode is electrically coupled to said bias voltage receiving means, and the gate electrode is constructed such that a potential variable in accordance with the internal voltage variation in the sensing device is applied to the gate electrode.

20. An image scanning system comprising:

(A) a radiation sensing device arranged to receive an image, said device having;

(a) radiation sensitive means for providing electrical signals corresponding to received radiations;

(b) means for providing an electrical signal indicative of a dark current of the sensing device;

(c) means for receiving a bias voltage to be supplied to said device; and

(d) means electrically coupled with said bias voltage receiving means so as to provide an electrical signal informing of internal voltage variation in said device relative to variation of said bias voltage,

wherein said radiation sensitive means, said dark current signal providing means, said bias voltage receiving means and said internal voltage variation information providing means are formed on or in the same semi-conductive substrate; and

(B) circuit means electrically coupled to said sensing device for compensating for the electrical signals provided by said radiation sensitive means with the electrical signal provided by said internal voltage variation information providing means and the dark current signal provided by said dark current signal providing means.

21. An image scanning system according to claim 20, wherein at least a portion of said circuit means is formed on or in said semi-conductive substrate.

22. An image scanning system according to claims 20 or 21, wherein said circuit means includes:

a first circuit for compensating for the electrical signals provided by said radiation sensitive means with the electrical signal provided by said internal voltage variation information providing means; and

a second circuit for compensating for the electrical signals provided by said radiation sensitive means with the dark current signal provided by said dark current signal providing means.

23. An image scanning system according to claims 20 or 21, wherein said circuit means includes;

a first circuit for compensating for the electrical signals provided by said radiation sensitive means and the dark current signal provided by said dark current signal providing means with the electrical signal provided by said internal voltage variation information providing means; and

a second circuit for compensating for the electrical signals compensated by the first circuit and related to the radiation sensitive means with the dark current signal compensated by the first circuit and related to the dark current signal providing means.

24. An image scanning system according to claim 20, wherein said internal voltage variation information providing means includes a field effect transistor having source, gate and drain electrode for producing the electrical signal information of internal voltage variation through the source electrode wherein the drain electrode is electrically coupled to said bias voltage receiving means, and the gate electrode is constructed such that a potential variable in accordance with the internal voltage variation in the sensing device is applied to the gate electrode.

25. A radiation sensing device comprising:

(a) radiation sensing means having a plurality of radiation sensitive elements, each for providing an electrical signal corresponding to received radiation, said plurality of radiation sensitive elements in said radiation sensing means being arranged in array;

(b) optically opaque means for shielding a portion of said radiation sensing means so that an electrical signal indicative of a dark current is provided by one or more radiation sensitive elements shielded by said opaque means, said optically opaque means shielding at least one radiation sensitive element located at or near the end of said array;

(c) time-seriation output means for emitting in seriatim electrical signals provided by said radiation sensitive elements in order of arrangement of said elements in the array;

(d) means for receiving a bias voltage to be supplied to said device; and

(e) means electrically coupled with said bias voltage receiving means so as to provide an electrical signal informing of internal voltage variation in said device relative to variation of said bias voltage,

wherein said optically opaque means is disposed to shield one or more such radiation sensitive elements the electrical signals of which are to be put out by said time-seriation output means relatively early in the output sequence, and

wherein said internal voltage variation information providing means includes a field effect transistor having source, gate and drain electrode for producing the electrical signal information of internal voltage variation through the source electrode wherein the drain electrode is electrically coupled to said bias voltage receiving means, and the gate electrode is constructed such that a potential variable in accordance with the internal voltage variation in the sensing device is applied to the gate electrode.