Light receiving device, method of controlling light receiving device, and electronic apparatus
A light receiving device of the present disclosure includes an imaging section in which a pixel including a light receiving element is disposed, a read processing section that reads a pixel signal from the imaging section, a signal processing section that executes predetermined signal processing on the pixel signal read by the read processing section, and a system controller, and has a short distance mode that is freely settable. The system controller has a function of calculating, when the short distance mode is set, a distance to a distance measurement target with use of the pixel signal in a partial region within a pixel region of the imaging section, and a function of determining whether or not the distance calculated satisfies a detection condition that is set in advance.
1 . A light receiving device, comprising:
an imaging section that comprises a pixel, wherein the pixel includes a light receiving element;
a read processing section that is configured to read a pixel signal from the imaging section;
a signal processing section that is configured to execute a predetermined signal processing on the pixel signal read by the read processing section; and
a system controller, wherein the light receiving device has a short distance mode that is freely settable, and
wherein the system controller is configured to:
calculate, based on the short distance mode being set, a distance to a distance measurement target with use of the pixel signal in a partial region within a pixel region of the imaging section,
determine whether the calculated distance satisfies a detection condition that is set in advance; and
stop an output of the pixel signal to outside the light receiving device through the signal processing section based on the calculation of the distance and the determination of whether the detection condition is satisfied, wherein the output of the pixel signal to outside the light receiving device is stopped based on a stoppage of supply of a clock to the signal processing section.
2 . The light receiving device according to claim 1 , wherein the system controller is further configured to stop the output of the pixel signal to outside the light receiving device based on a stoppage of supply of power to the signal processing section.
3 . The light receiving device according to claim 2 , wherein the system controller is further configured to stop supply of power to a circuit system including the read processing section during a vertical blanking period.
4 . The light receiving device according to claim 1 , further comprising a pixel integrator that is configured to integrate pixel values in the partial region within the pixel region of the imaging section, wherein the system controller is configured to calculate the distance to the distance measurement target with use of a result of the integration by the pixel integrator.
5 . The light receiving device according to claim 4 , wherein the pixel integrator is configured to integrate the pixel values in the partial region within the pixel region of the imaging section for a number of frames necessary for the calculation of the distance to the distance measurement target.
6 . The light receiving device according to claim 1 , wherein the detection condition is a distance value.
7 . The light receiving device according to claim 6 , wherein, based on an upper limit and a lower limit for the distance value as the detection condition, the system controller is further configured to determine that the detection condition is satisfied where a calculated distance value falls within a range between the upper limit and the lower limit, inclusive of the upper limit and the lower limit.
8 . The light receiving device according to claim 6 , wherein, based on an upper limit and a lower limit for the distance value as the detection condition, the system controller is further configured to determine that the detection condition is satisfied where a calculated distance value falls outside a range between the upper limit and the lower limit, inclusive of the upper limit and the lower limit.
9 . The light receiving device according to claim 1 , wherein the signal processing section includes a noise reduction circuit that is configured to perform a process of noise reduction on the pixel signal read by the read processing section.
10 . The light receiving device according to claim 9 , wherein:
as operation modes of the light receiving device, an infrared light mode for acquisition of an image based on infrared light and a distance mode for acquisition of a distance map image are settable, and the signal processing section includes:
a first register that is configured to set a relatively weak noise reduction function on the noise reduction circuit in a case where the light receiving device is in the infrared light mode, and
a second register that is configured to set a relatively intense noise reduction function on the noise reduction circuit in a case where the light receiving device is in the distance mode.
11 . The light receiving device according to claim 10 , wherein the system controller is further configured to:
select the first register or the second register based on an operation mode of the operation modes of the light receiving device; and
switch intensity settings of the relatively weak noise reduction function or the relatively intense noise reduction function on the noise reduction circuit.
12 . A method of controlling a light receiving device, the light receiving device including:
an imaging section that comprises a pixel, wherein the pixel includes a light receiving element;
a read processing section that is configured to read a pixel signal from the imaging section; and
a signal processing section that is configured to execute a predetermined signal processing on the pixel signal read by the read processing section,
wherein the light receiving device has a short distance mode that is freely settable, and wherein the method comprises:
calculating, based on the short distance mode being set, a distance to a distance measurement target with use of the pixel signal in a partial region within a pixel region of the imaging section, and
determining whether the calculated distance satisfies a detection condition that is set in advance; and
stopping an output of the pixel signal to outside the light receiving device through the signal processing section based on the calculation of the distance and the determination of whether the detection condition is satisfied, wherein the output of the pixel signal to outside the light receiving device is stopped based on a stoppage of supply of a clock to the signal processing section.
13 . An electronic apparatus, comprising:
a light source unit; and
a light receiving device, wherein the light receiving device includes:
an imaging section that comprises a pixel, wherein the pixel includes a light receiving element;
a read processing section that is configured to read a pixel signal from the imaging section;
a signal processing section that is configured to execute a predetermined signal processing on the pixel signal read by the read processing section; and
a system controller, wherein the light receiving device having a short distance mode that is freely settable, and
wherein the system controller is configured to-has a function of;
calculate, based on the short distance mode being set, a distance to a distance measurement target with use of the pixel signal in a partial region within a pixel region of the imaging section,
determine whether the calculated distance satisfies a detection condition that is set in advance; and
stop an output of the pixel signal to outside the light receiving device through the signal processing section based on the calculation of the distance and the determination of whether the detection condition is satisfied, wherein the output of the pixel signal to outside the light receiving device is stopped based on a stoppage of supply of a clock to the signal processing section.