IP Library Granted Patent US 10,791,601
Granted Patent B2
US 10,791,601 · App. 16/353,526 · Granted Sep 29, 2020

Light-emitting device

Inventors: Chao-Kai Chang (Hsinchu, TW); Chen-Yu Wang (Hsinchu, TW); Chang-Hseih Wu (Hsinchu, TW); Jai-Tai Kuo (Hsinchu, TW)
Assignee: EPISTAR CORPORATION
H05B45/37H05B45/10
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Quick Facts
Patent No.
US 10,791,601
App. No.
16/353,526
Granted
Sep 29, 2020
Kind
B2
Abstract

A light-emitting device has a stabilizing-current circuit, a current source having a high electron mobility transistor, and a light source electrically connected to the stabilizing-current circuit and the current source.

Claims (28)

1. A light-emitting device, comprising:

a light source having a first terminal and a second terminal;

a stabilizing-current circuit connected with the first terminal, the stabilizing-current circuit including:

a high electron mobility transistor;

a capacitor; and

a Zener diode having an anode connected with the capacitor, the Zener diode and the capacitor are connected with the high electron mobility transistor in parallel; and

a current source connected with the second terminal, and having a second transistor connected with the light source.

2. The light-emitting device of claim 1 , wherein the light source includes a filament connected with the stabilizing-current circuit and the current source in series.

3. The light-emitting device of claim 1 , further comprising a filter connected with the stabilizing-current circuit.

4. The light-emitting device of claim 1 , further comprising a bleeder circuit connected with the stabilizing-current circuit and the light source.

5. The light-emitting device of claim 4 , wherein the bleeder circuit is connected with the stabilizing-current circuit and the light source in parallel, and is connected with the current source in series.

6. The light-emitting device of claim 4 , wherein the bleeder circuit is connected with the light source through the current source.

7. The light-emitting device of claim 6 , wherein the bleeder circuit is connected with the stabilizing-current circuit, the light source and the current source in parallel.

8. A light-emitting device, comprising:

a first current source activated under a first voltage;

a stabilizing-current circuit activated under a second voltage, and electrically connected with the first current source, the stabilizing-current circuit including:

a capacitor;

a Zener diode, with an anode connected to the capacitor; and

a first resistor and a second resistor connected in series, wherein the first resistor and the second resistor are connected with the Zener diode and the capacitor in parallel;

a second current source electrically connected with the first current source; and

a light source activated under a third voltage, and electrically connected with the stabilizing-current circuit and the second current source, wherein the first voltage is lower than the third voltage and the third voltage is lower than the second voltage.

9. The light-emitting device of claim 8 , wherein the second current source includes two high electron mobility transistors connected in parallel.

10. The light-emitting device of claim 9 , wherein the first current source is connected with the stabilizing-current circuit, the light source and the second current source in parallel.

11. The light-emitting device of claim 8 , wherein the stabilizing-current circuit further includes a high electron mobility transistor connected with the Zener diode and the capacitor in parallel.

12. The light-emitting device of claim 8 , further comprising a filter connected with second current source in series.

13. The light-emitting device of claim 12 , wherein the first current source is connected with the filter and the second current source in parallel.

14. The light-emitting device of claim 8 , wherein the first current source is connected with the second current source in series.

15. The light-emitting device of claim 8 , wherein the first current source is closed when the light source is activated.

Assignments (2)
CHANGE OF NAME Recorded Feb 18, 2026
From: EPISTAR CORPORATION
To: ENNOSTAR CORPORATION
Reel/Frame 075171/0402 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 14, 2019
From: CHANG, CHAO-KAI; WANG, CHEN-YU; WU, CHANG-HSIEH; KUO, JAI-TAI
To: EPISTAR CORPORATION
Reel/Frame 048600/0991 →