Compensating for failed pixels in pixelated vehicle headlamps

Patent metadata

Field	Value
Publication number	US-11718220-B2
Application number	US-202117152519-A
Country	US
Kind code	B2
Filing date	Jan 19, 2021
Priority date	Jan 19, 2021
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A vehicle headlamp control circuit is configured to control a vehicle headlamp comprising a plurality of lighting elements. The vehicle headlamp control circuit may comprise a memory that stores information for controlling the plurality of lighting elements, and a driver circuit that drives the plurality of lighting elements based on the information, wherein the information compensates for one or more failed elements of the plurality of lighting elements.

First claim

The invention claimed is:

1. A vehicle headlamp control circuit configured to control a vehicle headlamp comprising a plurality of lighting elements, the vehicle headlamp control circuit comprising:
a memory that stores information for controlling the plurality of lighting elements; and
a driver circuit that drives the plurality of lighting elements based on the information, wherein the information compensates for one or more failed elements of the plurality of lighting elements, wherein the information comprises gamma corrections applied by the driver circuit in driving the plurality of lighting elements so as to compensate for one or more failed elements of the plurality of lighting elements.

2. The vehicle headlamp control circuit of claim 1 , wherein the information further comprises
standard driving values for active pixels surrounded by other active pixels, and compensating driving values for one or more active pixels that are neighboring one or more failed pixels, wherein the compensating driving values are larger than the standard driving values so as to compensate for the one or more failed pixels.

3. The vehicle headlamp control circuit of claim 1 , further comprising:
a graphics processor unit (GPU) that communicates bitmaps to the driver circuit, wherein the memory is coupled to the GPU and the information is used by the GPU to adjust the bitmaps to compensate for the one or more failed elements of the plurality of lighting elements.

4. The vehicle headlamp control circuit of claim 1 , wherein the memory is communicatively coupled to the driver circuit and the driver circuit receives bitmaps from a graphics processor unit (GPU), wherein the driver circuit adjusts the bitmaps based on based on the information in the memory to compensate for the one or more failed elements of the plurality of lighting elements.

5. The vehicle headlamp control circuit of claim 1 , wherein the memory is pre-configured to store locations of the failed elements.

6. The vehicle headlamp control circuit of claim 1 , wherein the memory is configured with locations of the failed elements that are updated during operation of the vehicle headlamp control circuit in response to failure data received from the driver circuit.

7. The vehicle headlamp control circuit of claim 1 wherein the gamma corrections compensate for the one or more failed pixels based on cross-talk.

8. The vehicle headlamp control circuit of claim 1 , wherein the plurality of lighting elements comprise individually controllable light emitting diodes (LEDs).

9. A method comprising:
manufacturing a driver circuit for driving a plurality of lighting elements of a vehicle headlamp based on information, wherein the information compensates for one or more failed elements of the plurality of lighting elements, wherein the information includes standard driving values for active pixels surrounded by other active pixels, and compensating driving values for one or more active pixels that are neighboring one or more failed pixels, wherein the compensating driving values are larger than the standard driving values so as to compensate for the one or more failed pixels;
calibrating the plurality of lighting elements to measure cross-talk in a manufacturing stage; and
defining the information based on the calibrating.

10. The method of claim 9 , further comprising:
storing the information in a memory.

11. The method of claim 10 , wherein the memory is communicatively coupled to a graphics processor unit (GPU) that communicates bitmaps to a driver circuit, the method further comprising manufacturing a system to be configured to:
receive a first bitmap in the GPU;
adjust the first bitmap to create a second bitmap based on the information;
communicate the second bitmap to the driver circuit; and
drive the plurality of lighting elements based on second bitmap.

12. The method of claim 10 , wherein the memory is communicatively coupled to a driver circuit, the method further comprising manufacturing a system to be configured to:
receive a first bitmap at the driver circuit from a graphics processor unit (GPU);
adjust the first bitmap to create a second bitmap based on the information; and
drive the plurality of lighting elements based on second bitmap.

13. The method of claim 10 , wherein the memory is pre-configured to store locations of the failed elements.

14. The method of claim 10 , wherein the memory is configured with locations of the failed elements in response to failure data, the method further comprising manufacturing a system to be configured to:
determine the failure data via a driver circuit; and
store the failure data in the memory.

15. The method of claim 14 , wherein the memory is communicatively coupled to the driver circuit and the driver circuit receives bitmaps from a graphics processor unit (GPU), the method further comprising manufacturing the system to be configured to:
adjust the bitmaps based on based on the failure data in the memory to compensate for the one or more failed elements of the plurality of lighting elements.

16. The method of claim 9 , further comprising manufacturing the plurality of lighting elements, wherein manufacturing the plurality of lighting elements includes:
determining a total number of failed pixels during a manufacturing stage;
using the plurality of lighting elements in the vehicle headlamp system in response to the total number being below a threshold, wherein using includes driving the plurality of lighting elements based on the information; and
discarding the plurality of lighting elements and using a different plurality of lighting elements in the vehicle headlamp system in response to the total number being above the threshold.

17. A system comprising:
a vehicle headlamp comprising a plurality of lighting elements; and
a vehicle headlamp control circuit configured to control the vehicle headlamp, the vehicle headlamp control circuit comprising:
a memory that stores information for controlling the plurality of lighting elements; and
a driver circuit that drives the plurality of lighting elements based on the information, wherein the information compensates for one or more failed elements of the plurality of lighting elements, wherein the information comprises gamma corrections applied by the driver circuit in driving the plurality of lighting elements so as to compensate for one or more failed elements of the plurality of lighting elements.

Assignees

• Infineon Technologies Ag

Inventors

• Bonart Dietrich
• Weis Michael
• Unterweger Gernot
• Piccolella Salvatore
• De Cicco Adolfo

Classifications

• B60Q1/1423 Primary

  Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic · CPC title

• B60Q1/08

  automatically · CPC title

• H05B45/12

  using optical feedback · CPC title

• H05B45/44 Primary

  with an active control inside an LED matrix · CPC title

• G09G3/32 Primary

  semiconductive, e.g. using light-emitting diodes [LED] · CPC title