LED matrix current control system

• US 6,160,354 A
• Filed: 07/22/1999
• Issued: 12/12/2000
• Est. Priority Date: 07/22/1999
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Ruvinskiy, Boris, Watts, William H.
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Dinh, Trinh Vo
• Application Number:
  US09/358,676
• Time in Patent Office: 509 Days
• Field of Search: 315/169.1, 315/169.2, 315/169.3, 340/811, 340/800, 340/362, 345/82, 345/45, 345/46, 345/47, 345/48, 345/49
• US Class Current: 315/169.3
• CPC Class Codes: G09G 2310/0267 Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
• CPC Class Codes: G09G 2310/0272 Details of drivers for data electrodes, the drivers communicating data to the pixels by means of a current
• CPC Class Codes: G09G 3/14 Semiconductor devices, e.g. diodes
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]

Abstract

A system for controlling the current supplied to an LED array includes an LED register which sends out individual signals to enable respective LED'"'"'s. A plurality of drivers are provided, whose outputs are tied together and supply the power to the LED array. A plurality of logic blocks controls the enablement of the plurality of drivers. Each logic block is in communication with the LED register to determine a number of LED'"'"'s enabled. Each logic block enables a respective driver depending on a number of the LED'"'"'s enabled.

Claims

1. An LED array current control system comprising:

an LED register array individually controllable of an enablement of a plurality of LED'"'"'s;

a plurality of drivers, each of said drivers having an output connected together and then connected to the plurality of LED'"'"'s for powering the plurality of LED'"'"'s;

a plurality of logic blocks, each of said plurality of logic blocks controlling enablement of one of said plurality of drivers, said each logic block being in communication with said LED register array to determine a total number of the LED'"'"'s enabled at one time, said each logic block enabling a respective said driver depending on a number of the LED'"'"'s to be enabled.

2. The system in accordance with claim 1, wherein:

said each logic block enables said respective driver depending on a different number of the LED'"'"'s to be enabled.

3. The system in accordance with claim 1, wherein:

said each logic block enables said respective driver when greater than a predetermined number of the LED'"'"'s are to be enabled.

4. The system in accordance with claim 3, wherein:

said predetermined number is different for each of said logic blocks.

5. The system in accordance with claim 1, wherein:

a number of said plurality of drivers is less than a number of the plurality of LED'"'"'s controlled by said LED register array at any one time.

6. The system in accordance with claim 1, wherein:

said output of said drivers provide a range of current during said enablement, said range having a maximum greater than a current required by one of the LED'"'"'s for enablement.

7. The system in accordance with claim 6, wherein:

said maximum is less than twice said current required by one of the LED'"'"'s for enablement.

8. The system in accordance with claim 4, wherein:

a number of said plurality of drivers is less than a number of the plurality of LED'"'"'s;

said output of said drivers provide a range of current during said enablement, said range having a maximum greater than a current required by one of the LED'"'"'s for enablement, said maximum is less than twice said current required by one of the LED'"'"'s for enablement.

9. An LED array current control system comprising:

an LED register array individually controllable of an enablement of a plurality of LED'"'"'s;

a plurality of drivers, each of said drivers having an output connected together and then connected to the plurality of LED'"'"'s for powering the plurality of LED'"'"'s;

a plurality of logic blocks, each of said plurality of logic blocks controlling enablement of one of said plurality of drivers, said each logic block being in communication with said LED register array to determine a number of the LED'"'"'s enabled, said each logic block enabling a respective said driver depending on a number of the LED'"'"'s to be enabled, said each logic block enables said respective driver depending on a different number of the LED'"'"'s to be enabled.