EP0108308A2
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EP
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Photoelectric conversion apparatus
Assignee: Toshiba Corp
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Filing: 1983-10-20
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Granted: —
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Expires: 2003-10-20
Abstract
Abstract Analog switches (3 i to 3 n ) are connected between corresponding photodiodes (1 i to 1 n ) and a common output line (4). The analog switches are sequentially scanned in response to scanning pulses (Ø 1 to 0 n ). During the ON period of each scanning pulse, the corresponding analog switch is turned on twice. A first circuit (C v , 5, 6, Ø R ) produces a first signal, including an image signal component and a noise signal component, when the analog switch is turned on for the first time, and produces a second signal including only the noise signal component, when the analog switch is turned on for the second time. A second circuit (11, 13) produces the signal derrived from the difference between the first and second signals, i.e., the image signal.
Inventors
- 👤 Shuji Kizu
- 👤 Tsuyoshi Ishida
- 👤 Kenichi Hiramatsu
- 👤 Junji Miura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 04:38
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40056; H04N25/00; H04N25/60
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
334 words
A photoelectric conversion apparatus comprising: an array of photoelectric conversion elements (1 1 to 1 n ), each of which produces an electric image signal component in response to a projected light; a common output line (4); a plurality of analog switches (3 1 to 3 n ), each of which is connected between said common output line and the corresponding photoelectric conversion element; and a pulse generating circuit (2) which produces a plurality of scanning pulses (φ 1 to φ n ), which pulses subsequently scan said analog switches, for reading out said image signal components on said common output line (4), in succession, by turning ON each of said analog switches for a predetermined time period; characterized in that said photoelectric conversion apparatus further comprises: means (φ IN ) for turning ON an analog switch (e.g., switch 3 1 ) during at least a first time period (TA) and a second time period (TB), during a predetermined time period in which said analog switch is scanned by a scanning pulse (φ 1 ) corresponding to said analog switch (31); first means (C V , 5, 6) connected to said common output line (4) and said pulse generating circuit (2), for use in obtaining a first signal (e S1 ) produced during said first time period (TA), which first signal includes said image signal component from a photoelectric element (1 1 ) and a noise signal component (e Nl ), and for obtaining a second signal (e Nl ) produced during said second time period (TB), which second signal (e N1 ) includes only said noise signal component (e N1 ); second means (11) connected to said first means and said pulse generating circuit (2), for holding said first signal (e Sl ) for a predetermined time period; and third means (13) connected to said first means and said second means (11), for producing said image signal component by subtracting said second signal (e Nl ) from said first signal (e S1 ).
Claim 2
Dependent Claim
334 words
A photoelectric conversion apparatus comprising: an array of photoelectric conversion elements (1 1 to 1 n ), each of which produces an electric image signal component in response to a projected light; a common output line (4); a plurality of analog switches (3 1 to 3 n ), each of which is connected between said common output line and the corresponding photoelectric conversion element; and a pulse generating circuit (2) which produces a plurality of scanning pulses (φ 1 to φ n ), which pulses subsequently scan said analog switches, for reading out said image signal components on said common output line (4), in succession, by turning ON each of said analog switches for a predetermined time period; characterized in that said photoelectric conversion apparatus further comprises: means (φ IN ) for turning ON an analog switch (e.g., switch 3 1 ) during at least a first time period (TA) and a second time period (TB), during a predetermined time period in which said analog switch is scanned by a scanning pulse (φ 1 ) corresponding to said analog switch (31); first means (C V , 5, 6) connected to said common output line (4) and said pulse generating circuit (2), for use in obtaining a first signal (e S1 ) produced during said first time period (TA), which first signal includes said image signal component from a photoelectric element (1 1 ) and a noise signal component (e Nl ), and for obtaining a second signal (e Nl ) produced during said second time period (TB), which second signal (e N1 ) includes only said noise signal component (e N1 ); second means (11) connected to said first means and said pulse generating circuit (2), for holding said first signal (e Sl ) for a predetermined time period; and third means (13) connected to said first means and said second means (11), for producing said image signal component by subtracting said second signal (e Nl ) from said first signal (e S1 ).
Claim 3
Dependent Claim
59 words
A photoelectric conversion apparatus according to claim 1, characterized in that said photoelectric conversion apparatus further comprises fourth means (14) connected to said third means (13) and said pulse generating circuit (2), for sampling said image signal component (e S1 - e Nl ) and preserving the sampled value for a predetermined time period in obtaining a video signal.
Claim 4
Dependent Claim
119 words
A photoelectric conversion apparatus according to claim 1, characterized in that said first means comprises a capacitor (C v ) connected between said common output line (4) and the earth terminal; a first amplifier (6) which is connected at one input terminal (+) to said common output line (4) and at the other input terminal to the output terminal thereof; and an analog switch (5) connected between said common output line (4) and the earth terminal; a clear pulse (φ R ) from said pulse generating circuit (2) controlling said analog switch (5) in such a way that said first amplifier (6) produces said first signal (e S1 ) and said second signal (e Nl ) at separate timings.
Claim 5
Dependent Claim
105 words
A photoelectric conversion apparatus according to claim 1, characterized in that said second means (11) comprises a second amplifier (15) which is connected at one input terminal (+) to the output terminal of said first means, through an analog switch (16), and at the other input terminal (-) to the output terminal thereof; and a capacitor (12) connected between said one input terminal and the ground terminal; a first sampling pulse (φ SP1 ) from said pulse generating circuit (2) controlling said analog switch (16) in such a way that said second means holds the first signal (e Sl ) for a predetermined time period.
Claim 6
Dependent Claim
87 words
A photoelectric conversion apparatus according to claim 1, characterized in that said third means comprises a differential amplifier (13) which is connected at one input terminal (+) to the output terminal of said first means, and at the other input terminal (-) to the output terminal of said second means; said differential amplifier (13) producing an image signal which is produced by subtracting a second signal (e N1 ) supplied from said first means from a first signal (e Sl ) supplied from said second means (11).
Claim 7
Dependent Claim
120 words
A photoelectric conversion apparatus according to claim 2, characterized in that said fourth means (14) comprises a third amplifier (17) which is connected at one input terminal (+) to the output terminal of said third means, through an analog switch (18), and at the other input terminal (-) to the output terminal thereof; and a capacitor (19) connected between the one input terminal of the third amplifier (17) and the earth terminal; a second sampling pulse (O SP2 ) from said pulse generating circuit (2) controlling said fourth means in such a way that said fourth means samples said image signal component from said third means, preserving the sampled signal for a predetermined time period, in producing a video signal.
References Cited (Backward Citations)
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