CN-118743237-B - Imaging device and reading control method

Abstract

An imaging device which realizes high-precision object tracking when imaging at a normal frame rate and which can continue AF processing while suppressing power consumption when imaging at a frame rate higher than the normal frame rate. The imaging device includes an imaging element in which a plurality of pixels are two-dimensionally arranged, the pixels including a first photoelectric conversion unit that receives a light flux passing through a first partial region of an imaging optical system and a second photoelectric conversion unit that receives a light flux passing through a second partial region different from the first partial region, and a read control unit that performs first read control when a first mode is selected, performs second read control when a second mode set to a high-speed frame rate is selected, the first read control causing individual charges of the first photoelectric conversion unit and the second photoelectric conversion unit to be subjected to AD conversion to generate a pixel signal, and causes individual charges of the first photoelectric conversion unit and the second photoelectric conversion unit to be subjected to AD conversion to generate a first pixel signal in the first pixels set discretely, and performs AD conversion to the charges of the first photoelectric conversion unit and the second photoelectric conversion unit to generate a second pixel signal in the second pixels other than the first pixels.

Inventors

• Yusuke Kohei

Assignees

• 北京小米移动软件有限公司

Dates

Publication Date

20260505

Application Date

20221227

Claims (2)

1. 1. An imaging device is characterized by comprising: A photographing element in which a plurality of pixels including at least a first photoelectric conversion portion that receives a light beam passing through a first partial region of an imaging optical system and a second photoelectric conversion portion that receives a light beam passing through a second partial region different from the first partial region are two-dimensionally arranged; A read control unit that performs first read control in a first mode and performs second read control in a second mode in which a frame rate is set to be higher than a frame rate set in the first mode, the first read control causing individual charges of the first photoelectric conversion unit and the second photoelectric conversion unit to be subjected to AD conversion to generate pixel signals, the second read control causing individual charges of the first photoelectric conversion unit and the second photoelectric conversion unit to be subjected to AD conversion in first pixels set discretely among the pixels to generate first pixel signals, and causing individual charges of the first photoelectric conversion unit and the second photoelectric conversion unit to be subjected to AD conversion to generate second pixel signals in second pixels other than the first pixels among the pixels, and A detection unit that performs phase difference detection focusing using pixel signals obtained by individually AD-converting charges of the first photoelectric conversion unit and the second photoelectric conversion unit, The detection unit makes a width of a window for generating a phase waveform larger when the read control unit performs the second read control than when the first read control is performed.
2. 2. A read control method, characterized by comprising: reading a pixel signal from a photographing element in which a plurality of pixels are two-dimensionally arranged, the pixels including a first photoelectric conversion portion that receives a light beam passing through a first partial region of an imaging optical system and a second photoelectric conversion portion that receives a light beam passing through a second partial region different from the first partial region, Determining one mode from a first mode and a second mode in which a frame rate is set higher than that set in the first mode; In a first mode, performing a first read control for generating a pixel signal by performing AD conversion on charges of the first photoelectric conversion unit and the second photoelectric conversion unit separately, in a second mode, performing a second read control for generating a first pixel signal by performing AD conversion on charges of the first photoelectric conversion unit and the second photoelectric conversion unit separately in a first pixel set discretely among the pixels and adding charges of the first photoelectric conversion unit and the second photoelectric conversion unit separately in a second pixel other than the first pixel, and generating a second pixel signal by performing AD conversion on the charges of the first photoelectric conversion unit and the second photoelectric conversion unit separately in the second pixel other than the first pixel, and Using pixel signals obtained by performing AD conversion on the charges of the first photoelectric conversion part and the second photoelectric conversion part separately, performing phase difference detection focusing, Wherein a width of a window for generating a phase waveform when the second reading control is performed is larger than that when the first reading control is performed.

Description

Imaging device and reading control method Technical Field The present invention relates to an imaging device and a read control method for reading pixel signals from an imaging element. Background An imaging device that performs autofocus control using a phase difference signal obtained from an image plane of an imaging element is known. An imaging element capable of outputting such a phase difference signal includes two photoelectric conversion portions in which each pixel is pupil-divided for one microlens. If the respective pixel signals output from the two photoelectric conversion sections are used as separate phase difference signals, defocus amount calculation for Autofocus (AF) can be used. If the pixel signals output from the two photoelectric conversion portions are added together as an image signal, the image signals of the effective pixels can be collected to generate a frame image as an object image (for example, refer to patent document 1). Recent imaging devices employ such imaging elements, and perform high-precision AF even in video photographing, and can maintain an in-focus state even for a moving subject. In addition, the total number of pixels of the imaging element is gradually increased, and accordingly the focusing accuracy is also improved. Prior art literature Patent literature JP-A2017-134154 (the following patent document 1). Disclosure of Invention Problems to be solved by the invention The later-described mode is popular in that it is possible to enjoy a high-frame mode (slow-motion mode) of an object image that moves more slowly and smoothly than practical by shooting at a higher frame rate than usual at shooting and replaying at a usual frame rate at replaying. In the high frame mode, since the pixel signals are read at a frame rate higher than usual, a large amount of power is consumed, and the reading process of the pixel signals may not be followed in some cases. If the reading process of the pixel signal cannot keep pace, the AF process fails and the in-focus state of the subject cannot be maintained. The present invention has been made to solve the above-described problems, and an object tracking device and the like are provided that achieve high-precision object tracking when shooting at a normal frame rate, and that can continue AF processing while suppressing power consumption when shooting at a frame rate higher than the normal frame rate. Solution for solving the problem An imaging device according to a first aspect of the present invention includes an imaging element in which a plurality of pixels are two-dimensionally arranged, the pixels including a first photoelectric conversion unit that receives a light flux passing through a first partial region of an imaging optical system and a second photoelectric conversion unit that receives a light flux passing through a second partial region different from the first partial region, and a read control unit that performs first read control when a first mode is selected, performs second read control when a second mode in which a frame rate is set higher than a frame rate set in the first mode is selected, the first read control causing individual charges of the first photoelectric conversion unit and the second photoelectric conversion unit to perform AD conversion to generate a pixel signal, the second read control causing individual charges of the first photoelectric conversion unit and the second photoelectric conversion unit to perform AD conversion to generate a first signal in a first pixel that is set discretely among the pixels, and causing individual charges of the first photoelectric conversion unit and the second photoelectric conversion unit to perform AD conversion to generate a second signal in a second pixel that is not the first pixel, and the first photoelectric conversion unit performs AD conversion to generate a first signal in the pixel. The method for controlling reading in the second aspect of the present invention includes reading a pixel signal from an imaging element in which a plurality of pixels are two-dimensionally arranged, the pixels including a first photoelectric conversion section that receives a light beam passing through a first partial region of an imaging optical system and a second photoelectric conversion section that receives a light beam passing through a second partial region different from the first partial region, determining one mode from a first mode and a second mode in which a frame rate is set higher than a frame rate set in the first mode, performing first reading control in the first mode and performing second reading control in the second mode, wherein the first reading control causes respective charges of the first photoelectric conversion section and the second photoelectric conversion section to be individually AD-converted to generate an imaging pixel signal, the second reading control causes the respective charges of the first photoelectric conversion section and th