Anti-flicker mechanism for a digital camera

Patent metadata

Field	Value
Publication number	US-12335633-B2
Application number	US-202318180391-A
Country	US
Kind code	B2
Filing date	Mar 8, 2023
Priority date	Mar 8, 2023
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

An information handling system includes a camera, a neutral density (ND) filter, and a processor. The camera captures video images for display on a display device of the information handling system. The processor communicates with the camera. The processor determines a brightness level of an ambient light and a first shutter speed of the camera. The processor sets a stop level for the ND filter based on the brightness level of the ambient light and the first shutter speed. In response to the stop level of the ND filter being set, the processor sets the camera to a second shutter speed.

First claim

What is claimed is:

1. An information handling system comprising:
a camera to capture video images for display on a display device of the information handling system;
a neutral density (ND) filter; and
a processor to communicate with the camera, the processor to:
determine a brightness level of an ambient light;
determine a first shutter speed of the camera;
set a stop level for the ND filter based on the brightness level of the ambient light and the first shutter speed; and
in response to the stop level of the ND filter being set, set the camera to a second shutter speed, wherein a first amount of the ambient light let into the camera by the first shutter speed is equal to a second amount of the ambient light let into the camera by a combination of the second shutter speed and the stop level of the ND filter.

2. The information handling system of claim 1 , wherein the stop level for the ND filter allows a fraction of the ambient light into the camera.

3. The information handling system of claim 1 , wherein the second shutter speed is slower than the first shutter speed.

4. The information handling system of claim 1 , wherein the processor further to:
determine whether an ISO gain of the camera is above a threshold value; and
based on the ISO gain being above the threshold value, disable the ND filter.

5. The information handling system of claim 1 , wherein processor is further to:
determine whether the brightness level is above a predetermined level; and
based on the brightness level being above predetermined level, enable the ND filter.

6. The information handling system of claim 1 , wherein the second shutter speed is set to a value that is greater than a threshold shutter speed.

7. The information handling system of claim 1 , wherein prior to the setting of the stop level for the ND filter, the method further comprises: selecting the stop level from an ISO/ND table in a memory of the information handling system.

8. The information handling system of claim 1 , wherein processor is further to: reduce a rate that a shutter speed of the camera is increased as the brightness level increases.

9. A method comprising:
determining, by a processor of an information handling system, a brightness level of an ambient light;
determining a first shutter speed of a camera of the information handling system;
setting a stop level for a neutral density (ND) filter based on the brightness level of the ambient light and the first shutter speed; and
in response to the stop level of the ND filter being set, setting the camera to a second shutter speed, wherein the second shutter speed is set to a value that is greater than a threshold shutter speed.

10. The method of claim 9 , wherein the stop level for the ND filter allows a fraction of the ambient light into the camera.

11. The method of claim 9 , wherein a first amount of the ambient light let into the camera by the first shutter speed is equal to a second amount of the ambient light let into the camera by a combination of the second shutter speed and the stop level of the ND filter.

12. The method of claim 9 , wherein the second shutter speed is slower than the first shutter speed.

13. The method of claim 9 , further comprising:
determining whether an ISO gain of the camera is above a threshold value; and
based on the ISO gain being above the threshold value, disabling the ND filter.

14. The method of claim 9 , further comprising:
determining whether the brightness level is above a predetermined level; and
based on the brightness level being above predetermined level, enabling the ND filter.

15. The method of claim 9 , wherein prior to the setting of the stop level for the ND filter, the method further comprises: selecting the stop level from an ISO/ND table in a memory of the information handling system.

16. The method of claim 9 , further comprising: reducing a rate that a shutter speed of the camera is increased as the brightness level increases.

17. An information handling system comprising:
a camera to capture video images for display on a display device of the information handling system;
an infrared-cut filter in physical communication with the camera, the infrared-cut filter to filter out infrared light from the captured video images;
a glass in physical communication with the infrared-cut filter;
a neutral density (ND) filter in physical communication with the glass; and
a processor to:
determine a brightness level of an ambient light;
determine a first shutter speed of the camera;
set a stop level for the ND filter based on the brightness level of the ambient light and the first shutter speed; and
set the camera to a second shutter speed, wherein the stop level for the ND filter allows a fraction of the ambient light into the camera, wherein the second shutter speed is slower than the first shutter speed.

18. The information handling system of claim 17 , wherein a first amount of the ambient light let into the camera by the first shutter speed is equal to a second amount of the ambient light let into the camera by a combination of the second shutter speed and the stop level of the ND filter.

19. The information handling system of claim 17 , wherein the processor further to:
determine whether an ISO gain of the camera is above a threshold value; and
based on the ISO gain being above the threshold value, disable the ND filter.

20. The information handling system of claim 17 , wherein processor is further to:
determine whether the brightness level is above a predetermined level; and
based on the brightness level being above predetermined level, enable the ND filter.

Assignees

• Dell Products Lp

Inventors

• Liao Chien-Chih
• Chua Shiong Kheng
• Yu Paul

Classifications

• H04N23/73 Primary

  by influencing the exposure time · CPC title

• G02B5/205

  Neutral density filters · CPC title

• H04N23/75

  by influencing optical camera components · CPC title

• H04N23/745 Primary

  Detection of flicker frequency or suppression of flicker wherein the flicker is caused by illumination, e.g. due to fluorescent tube illumination or pulsed LED illumination · CPC title