Solid-state imaging device
View Patent ↗A solid-state imaging device which can, in response to the problem of black-crush occurring in an image when strong light is enters the device, positively detect black-crush in a state in which a variance margin has been secured. The solid-state imaging device outputs a luminance signal in accordance with an amount of received light, and includes: a pixel circuit having a light-receiving element; a signal output circuit having a sampling transistor which outputs, from a second signal output line, a luminance signal in accordance with the amount of light received by the light-receiving element, based on an output signal from the pixel circuit; and a high-intensity judgment circuit which is coupled by the pixel circuit and a judgment input coupling capacitor, judges whether or not light entering the light-receiving element is of high intensity based on the output signal from the pixel circuit, and in the case of judging the entering light to be of high intensity, outputs a luminance signal indicating high intensity.
1. A solid-state imaging device, comprising:
an imaging unit in which plural pixel circuits are arranged one- or two-dimensionally, each pixel circuit including a photoelectric converter, and each pixel circuit outputting a reset voltage and a read voltage, the reset voltage being generated when said photoelectric converter is reset, and the read voltage being generated through photoelectric conversion performed by said photoelectric converter;
a first signal output line that is connected to a number of said pixel circuits and that carries the reset voltage and the read voltage output from said pixel circuits;
a signal output circuit that outputs, from a second signal output line, a luminance signal in accordance with an amount of light received by said photoelectric converter, based on the reset voltage and the read voltage output to said first signal output line;
a signal amplifier that is positioned between said pixel circuits and said second signal output line, and that inverts and amplifies the reset voltage and the read voltage output from said pixel circuits; and
a high-intensity judgment circuit connected to said signal amplifier,
wherein said high-intensity judgment circuit judges whether or not light entering said photoelectric converter is of high intensity based on a voltage signal in said first signal output line, which is output from said pixel circuits, and, upon judging that entering light is of high intensity, outputs luminance information indicating that the entering light is of high intensity instead of outputting the luminance signal, indicating a difference between the reset voltage and the read voltage, and
wherein said high-intensity judgment circuit includes a capacitor connected to said first signal output line and judges whether or not the light entering said photoelectric converter is of high intensity based on an AC component of the voltage signal in said first signal output line.
2. The solid-state imaging device according to claim 1 ,
wherein said high-intensity judgment circuit includes a judgment input circuit connected to said first signal output line.
3. The solid state imaging device according to claim 1 ,
wherein said high-intensity judgment circuit includes:
said capacitor connected to said first signal output line; and
a judgment amplifier connected to said first signal output line via said capacitor, and
wherein said judgment amplifier judges whether or not the light entering said photoelectric converter is of high intensity based on the AC component of the voltage signal in said first signal output line.
4. The solid state imaging device according to claim 3 ,
wherein said high-intensity judgment circuit further includes a reset transistor that resets said judgment amplifier, and
an input of said judgment amplifier and an output of said reset transistor are connected to each other.
5. The solid state imaging device according to claim 3 ,
wherein said judgment amplifier judges whether or not the light entering said photoelectric converter is of high intensity based on the AC component of the voltage signal in said first signal output line and a judgment reference voltage.
6. The solid-state imaging device according to claim 5 ,
wherein said high-intensity judgment circuit further includes an adding circuit that adds the AC component of the voltage signal in said first signal output line and the judgment reference voltage, and
said judgment amplifier judges whether or not the light entering said photoelectric converter is of high intensity based on the AC component of the voltage signal after the adding is performed by said adding circuit.
7. The solid-state imaging device according to claim 6 ,
wherein said judgment amplifier judges whether or not the light entering said photoelectric converter is of high intensity by comparing a voltage of the voltage signal after the adding is performed by said adding circuit with a predetermined threshold voltage.
8. The solid-state imaging device according to claim 3 ,
wherein one end of said capacitor is connected to said first signal output line, and the other end of said capacitor is connected to said judgment amplifier.
9. A solid-state imaging device that outputs luminance information in accordance with an amount of light entering said device, said device comprising:
an imaging unit in which plural pixel circuits are arranged one- or two-dimensionally, each pixel circuit including a photoelectric converter, each pixel circuit outputting a reset voltage and a read voltage, the reset voltage corresponding to an output voltage of said photoelectric converter, and the read voltage corresponding to an output voltage of said photoelectric converter in accordance with the amount of light received by said solid state imaging device;
a signal output circuit that outputs luminance information indicating a difference between the reset voltage and the read voltage, and includes a sampling circuit that holds the luminance information indicating the difference;
a signal amplifier that is positioned between said pixel circuits and said sampling circuit, and that inverts and amplifies the reset voltage and the read voltage output from said pixel circuits; and
a high-intensity judgment circuit connected in parallel to said signal amplifier,
wherein said high-intensity judgment circuit judges whether or not light entering said photoelectric converter is of high intensity by judging whether or not the read voltage output from said pixel circuit falls within a predetermined range and, upon judging that entering light is of high intensity, outputs luminance information indicating that the entering light is of high intensity instead of outputting luminance information indicating the difference in said signal output circuit, and
wherein said high-intensity judgment circuit includes a capacitor connected to a first signal output line that is connected to a number of plural pixel circuits and judges whether or not the light entering said photoelectric converter is of high intensity based on an AC component of a voltage signal in said first signal output line.