Light source apparatus, discharge lamp driving method, and projector

• US 9,642,229 B2
• Filed: 04/21/2014
• Issued: 05/02/2017
• Est. Priority Date: 06/15/2011
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Suzuki, Junichi, Kito, Satoshi
• Primary Examiner(s): Tan, Vibol
• Application Number:
  US14/257,427
• Publication Number:
  US 20140226135A1
• Time in Patent Office: 1,107 Days
• CPC Class Codes: G03B 21/2026 Gas discharge type light sources, e.g. arcs
• CPC Class Codes: G03B 21/206 Control of light source other than position or intensity
• CPC Class Codes: H05B 41/2858 for protecting the lamp against abnormal operating conditions
• CPC Class Codes: H05B 41/36 Controlling

Abstract

In at least one embodiment, a light source apparatus includes a discharge lamp with a pair of electrodes and a driving unit that supplies a driving current to the pair of electrodes. The driving unit includes an AC supplier that supplies an alternating current to the pair of electrodes and a DC supplier that supplies a direct current to the pair of electrodes. The AC supplier is configured to alternately repeat an AC supply section in which the alternating current is supplied and an AC stop section in which the supply of the alternating current is stopped. The DC supplier is configured to supply the direct current during a period corresponding to the AC stop section. A frequency of the direct current is not lower than 10 Hz and not higher than 1 kHz.

Claims

1. A light source apparatus comprising:

a discharge lamp including a pair of electrodes; and

a driving unit that supplies a driving current to the pair of electrodes,

wherein the driving unit includes an AC supplier that supplies an alternating current to the pair of electrodes and a DC supplier that supplies a direct current to the pair of electrodes,

the AC supplier is configured so as to alternately repeat an AC supply section in which the alternating current is supplied and an AC stop section in which the supply of the alternating current is stopped,

the DC supplier is configured so as to supply the direct current during a period corresponding to the AC stop section,

the period corresponding to the AC stop section is not lower than 10 μ

sec and not higher than 100 msec, and

a frequency of the alternating current is higher than 1 kHz and not higher than 10 GHz.

2. The light source apparatus according to claim 1,

wherein the period corresponding to the AC supply section is not lower than 1 msec and not higher than 100 msec.

3. The light source apparatus according to claim 1,

wherein a direction of the direct current is changed at least once while the direct current is supplied to the light source apparatus.

4. The light source apparatus according to claim 1,

wherein the direct current is supplied during an entire period corresponding to the AC stop section.

5. The light source apparatus according to claim 1,

wherein the AC stop section includes a period in which the supply of the direct current is also stopped.

6. The light source apparatus according to claim 1,

wherein a magnitude of the direct current is maintained constant while the direct current is supplied.

7. The light source apparatus according to claim 1,

wherein an average magnitude of the alternating current in the AC supply section is the same as a magnitude of the direct current supplied in the period corresponding to the AC stop section.

8. The light source apparatus according to claim 1,

wherein a magnitude of the alternating current is maintained constant in the AC supply section.

9. The light source apparatus according to claim 1,

wherein a magnitude of the alternating current is set to gradually vary in the AC supply section.

10. The light source apparatus according to claim 1,

wherein the frequency of the alternating current is higher than 1 kHz and not higher than 100 kHz, or not lower than 3 MHz and not higher than 10 GHz.

11. A projector comprising:

a light source apparatus that emits a light;

a modulation unit that modulates the light emitted from the light source apparatus on a basis of an image data; and

a projecting unit that projects the light modulated by the modulation unit,

wherein the light source apparatus includes;

a discharge lamp including a pair of electrodes, and

a driving unit that supplies a driving current to the pair of electrodes,

the driving unit includes an AC supplier that supplies an alternating current to the pair of electrodes and a DC supplier that supplies a direct current to the pair of electrodes,

the AC supplier is configured so as to alternately repeat an AC supply section in which the alternating current is supplied and an AC stop section in which the supply of the alternating current is stopped,

the DC supplier is configured so as to supply the direct current during a period corresponding to the AC stop section,

the period corresponding to the AC stop section is not lower than 10 μ

sec and not higher than 100 msec, and

a frequency of the alternating current is higher than 1 kHz and not higher than 10 GHz.

12. A light source apparatus comprising:

a discharge lamp including a pair of electrodes; and

a driving unit that supplies a driving current to the pair of electrodes,

wherein the driving unit includes an AC supplier that supplies an alternating current to the pair of electrodes and a DC supplier that supplies a direct current to the pair of electrodes,

the AC supplier is configured so as to alternately repeat an AC supply section in which the alternating current is supplied and an AC stop section in which the supply of the alternating current is stopped,

the DC supplier is configured so as to supply the direct current during a period corresponding to the AC stop section,

a frequency of the alternating current is higher than 1 kHz and not higher than 10 GHz, and

a ratio B/A is not lower than 50% and not higher than 99%, where A represents a total of the periods corresponding to the AC supply section and the AC stop section, and B represents the period corresponding to the AC supply section.

13. The light source apparatus to claim 12,

wherein the period corresponding to the AC supply section is not lower than 1 msec and not higher than 100 msec.

14. The light source apparatus according to claim 12,

wherein the direct current is supplied during an entire period corresponding to the AC stop section.

15. The light source apparatus according to claim 12,

wherein the AC stop section includes a period in which the supply of the direct current is also stopped.

16. The light source apparatus according to claim 12,

wherein a magnitude of the direct current is maintained constant while the direct current is supplied.

17. The light source apparatus according to claim 12,

wherein a magnitude of the alternating current is maintained constant in the AC supply section.

18. The light source apparatus according to claim 12,

wherein a magnitude of the alternating current is set to gradually vary in the AC supply section.

19. The light source apparatus according to claim 12,

wherein the frequency of the alternating current is higher than 1 kHz and not higher than 100 kHz, or not lower than 3 MHz and not higher than 10 GHz.

20. A projector comprising:

a light source apparatus that emits a light;

a modulation unit that modulates the light emitted from the light source apparatus on a basis of an image data; and

a projecting unit that projects the light modulated by the modulation unit,

wherein the light source apparatus includes;

a discharge lamp including a pair of electrodes, and

a driving unit that supplies a driving current to the pair of electrodes,

the driving unit includes an AC supplier that supplies an alternating current to the pair of electrodes and a DC supplier that supplies a direct current to the pair of electrodes,

the AC supplier is configured so as to alternately repeat an AC supply section in which the alternating current is supplied and an AC stop section in which the supply of the alternating current is stopped,

the DC supplier is configured so as to supply the direct current during a period corresponding to the AC stop section,

a frequency of the alternating current is higher than 1 kHz and not higher than 10 GHz, and

a ratio B/A is not lower than 50% and not higher than 99%, where A represents a total of the periods corresponding to the AC supply section and the AC stop section, and B represents the period corresponding to the AC supply section.

21. A light source apparatus comprising:

a discharge lamp including a pair of electrodes; and

a driving unit that supplies a driving current to the pair of electrodes,

wherein the driving unit includes an AC supplier that supplies an alternating current to the pair of electrodes and a DC supplier that supplies a direct current to the pair of electrodes,

the AC supplier is configured so as to alternately repeat an AC supply section in which the alternating current is supplied and an AC stop section in which the supply of the alternating current is stopped,

the DC supplier is configured so as to supply the direct current during a period corresponding to the AC stop section,

a frequency of the alternating current is higher than 1 kHz and not higher than 10 GHz, and

a projection is formed on a tip portion of each of the pair of electrodes while the discharge lamp is turned on because of a fluctuation of a temperature of the pair of electrodes.

22. The light source apparatus to claim 21,

wherein the period corresponding to the AC supply section is not lower than 1 msec and not higher than 100 msec.

23. The light source apparatus according to claim 21,

wherein the direct current is supplied during an entire period corresponding to the AC stop section.

24. The light source apparatus according to claim 21,

wherein the AC stop section includes a period in which the supply of the direct current is also stopped.

25. The light source apparatus according to claim 21,

wherein a magnitude of the direct current is maintained constant while the direct current is supplied.

26. The light source apparatus according to claim 21,

wherein a magnitude of the alternating current is maintained constant in the AC supply section.

27. The light source apparatus according to claim 21,

wherein a magnitude of the alternating current is set to gradually vary in the AC supply section.

28. The light source apparatus according to claim 21,

wherein the frequency of the alternating current is higher than 1 kHz and not higher than 100 kHz, or not lower than 3 MHz and not higher than 10 GHz.

29. A projector comprising:

a light source apparatus that emits a light;

a modulation unit that modulates the light emitted from the light source apparatus on a basis of an image data; and

a projecting unit that projects the light modulated by the modulation unit,

wherein the light source apparatus includes;

a discharge lamp including a pair of electrodes, and

a driving unit that supplies a driving current to the pair of electrodes,

the driving unit includes an AC supplier that supplies an alternating current to the pair of electrodes and a DC supplier that supplies a direct current to the pair of electrodes,

the AC supplier is configured so as to alternately repeat an AC supply section in which the alternating current is supplied and an AC stop section in which the supply of the alternating current is stopped,

the DC supplier is configured so as to supply the direct current during a period corresponding to the AC stop section,

a frequency of the alternating current is higher than 1 kHz and not higher than 10 GHz, and

a projection is formed on a tip portion of each of the pair of electrodes while the discharge lamp is turned on because of a fluctuation of a temperature of the pair of electrodes.