Image sensor, camera assembly, and mobile terminal

Patent metadata

Field	Value
Publication number	US-12419123-B2
Application number	US-202217575298-A
Country	US
Kind code	B2
Filing date	Jan 13, 2022
Priority date	Sep 30, 2019
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

Provided are an image sensor ( 10 ), a camera assembly ( 40 ), and a mobile terminal ( 90 ). The image sensor ( 10 ) includes panchromatic pixels and color pixels. The color pixels have a narrower spectral response than the panchromatic pixels, and the color pixels have a larger conversion gain than the panchromatic pixels.

First claim

What is claimed is:

1. An image sensor, comprising:
panchromatic pixels; and
color pixels each having a narrower spectral response and a greater conversion gain than the panchromatic pixels, the conversion gain of each of the panchromatic pixels and the color pixels being in negative correlation with a capacitance value of an additional capacitor of the pixel;
wherein each of the panchromatic pixels comprises a first additional capacitor connected to a floating diffusion unit of the panchromatic pixel, and each of the color pixels comprises no additional capacitor;
or,
wherein each of the panchromatic pixels comprises a first additional capacitor connected to a floating diffusion unit of the panchromatic pixel, each of the color pixels comprises a second additional capacitor connected to a floating diffusion unit of the color pixel, the capacitance value of the first additional capacitor of each of the panchromatic pixels is larger than the capacitance value of the second additional capacitor of each of the color pixels.

2. The image sensor according to claim 1 , wherein each of the panchromatic pixels and the color pixels further comprises:
a photoelectric conversion element; and
an exposure control circuit connected to the photoelectric conversion element and the floating diffusion unit.

3. The image sensor according to claim 2 , wherein each of the panchromatic pixels further comprises a first switch circuit connected between the floating diffusion unit and the first additional capacitor of the panchromatic pixel, and each of the color pixels further comprises a second switch circuit connected between the floating diffusion unit and the second additional capacitor of the color pixel;
wherein when it is detected that an ambient brightness is higher than a brightness threshold, each first switch circuit is configured to be switched on to connect the first additional capacitor with the floating diffusion unit of the respective panchromatic pixel; and
wherein when it is detected that the ambient brightness is lower than the brightness threshold, each first switch circuit is configured to be switched off to disconnect the first additional capacitor from the floating diffusion unit of the respective panchromatic pixel, and each second switch circuit is configured to be switched off to disconnect the second additional capacitor from the floating diffusion unit of the respective color pixel.

4. The image sensor according to claim 1 , wherein the panchromatic pixels have a greater full-well capacity than the color pixels,
wherein each of the panchromatic pixels and the color pixels comprises a photoelectric conversion element, and the photoelectric conversion element comprises a substrate and an n-potential well layer formed within the substrate.

5. The image sensor according to claim 4 , wherein a cross-section of the n-potential well layer of each of the panchromatic pixels has a same size as a cross-section of the n-potential well layer of each of the color pixels, and the n-potential well layer of each of the panchromatic pixels has a greater depth than the n-potential well layer of each of the color pixels; or
wherein the cross-section of the n-potential well layer of each of the panchromatic pixels has a greater size than the cross-section of the n-potential well layer of each of the color pixels, and the n-potential well layer of each of the panchromatic pixels has a greater depth than or a same depth as the n-potential well layer of each of the color pixels.

6. The image sensor according to claim 5 , wherein sizes of the cross-sections of the n-potential well layer of each of the panchromatic pixels and the color pixels are equal along a light-receiving direction of the image sensor.

7. The image sensor according to claim 5 , wherein along a light-receiving direction of the image sensor, sizes of the cross-sections of the n-potential well layer of each of the panchromatic pixels gradually increase; sizes of the cross-sections of the n-potential well layer of each of the color pixels gradually decrease; and the smallest cross-section of the n-potential well layer of each of the panchromatic pixels has a greater size than or a same size as the largest cross-section of the n-potential well layer of each of the color pixels.

8. The image sensor according to claim 1 , wherein each of the panchromatic pixels and the color pixels comprises a microlens, a filter, an isolation layer, and a photoelectric conversion element that are arranged in sequence along a light-receiving direction of the image sensor.

9. The image sensor according to claim 8 , wherein each of the panchromatic pixels and the color pixels further comprises a light-guiding layer formed within the isolation layer and having a greater refractive index than the isolation layer.

10. The image sensor according to claim 8 , wherein each of the panchromatic pixels and the color pixels further comprises a condenser lens arranged in the isolation layer.

11. The image sensor according to claim 1 , further comprising a barrier layer arranged between photoelectric conversion elements of two adjacent pixels of the panchromatic pixels and the color pixels.

12. The image sensor according to claim 1 , wherein the panchromatic pixels and the color pixels are arranged in a two-dimensional pixel array comprising minimum repeating units,
wherein in each of the minimum repeating units, the panchromatic pixels are arranged in a first diagonal direction, and the color pixels are arranged in a second diagonal direction, the first diagonal direction being different from the second diagonal direction, and
wherein first exposure time of at least two adjacent panchromatic pixels in the first diagonal direction is controlled by a first exposure signal, second exposure time of at least two adjacent color pixels in the second diagonal direction is controlled by a second exposure signal, and the first exposure time is shorter than the second exposure time.

13. The image sensor according to claim 12 , further comprising:
a first exposure control line electrically connected to a control terminal of an exposure control circuit in each of the at least two adjacent panchromatic pixels in the first diagonal direction; and
a second exposure control line electrically connected to a control terminal of an exposure control circuit in each of the at least two adjacent color pixels in the second diagonal direction,
wherein the first exposure signal is transmitted via the first exposure control line, and the second exposure signal is transmitted via the second exposure control line.

14. The image sensor according to claim 13 , wherein the first exposure control line has a “W” shape and is electrically connected to the control terminal of the exposure control circuit in each of the panchromatic pixels in two adjacent rows of the two-dimensional pixel array; and
wherein the second exposure control line has a “W” shape and is electrically connected to the control terminal of an exposure control circuit in each of the color pixels in two adjacent rows.

15. The image sensor according to claim 13 , wherein the exposure control circuit is electrically connected to a photoelectric conversion element and configured to transfer an electric potential accumulated at the photoelectric conversion element after being irradiated, and
wherein the exposure control circuit is a transfer transistor, and the control terminal of the exposure control circuit is a gate of the transfer transistor.

16. The image sensor according to claim 12 , wherein each of the minimum repeating units comp

Assignees

• Guangdong Oppo Mobile Telecommunications Corp Ltd

Inventors

• Tang Cheng
• Zhang Gong
• Zhang Haiyu
• Yang Xin
• Xu Rui
• Lan He
• Sun Jianbo
• Li Xiaotao
• Wang Wentao

Classifications

• H04N25/75

  Circuitry for providing, modifying or processing image signals from the pixel array · CPC title

• H04N23/10

  for generating image signals from different wavelengths · CPC title

• H10F39/8063

  Microlenses · CPC title

• H10F39/182

  Colour image sensors · CPC title

• H04N25/771

  comprising storage means other than floating diffusion · CPC title