Discharge lamp driving device, projector, and discharge lamp driving method

Patent metadata

Field	Value
Publication number	US-9930305-B2
Application number	US-201715474085-A
Country	US
Kind code	B2
Filing date	Mar 30, 2017
Priority date	Apr 6, 2016
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A discharge lamp driving device includes a discharge lamp driving unit configured to supply a driving current to a discharge lamp, and a control unit configured to control the discharge lamp driving unit. The discharge lamp driving device is configured to provide a first hybrid period and a second hybrid period each alternately including a first AC period in which an AC current is supplied and a first DC period in which a DC current with a first polarity is supplied. The control unit, in the first hybrid period, is configured to change a ratio of length of the first DC period to length of the first AC period to be increased, and in the second hybrid period, is configured to change a ratio of the length of the first AC period to the length of the first DC period to be increased.

First claim

What is claimed is:

1. A discharge lamp driving device comprising:
a discharge lamp driving unit configured to supply a driving current to a discharge lamp provided with a first electrode and a second electrode; and
a control unit configured to control the discharge lamp driving unit,
wherein the discharge lamp driving device is configured to provide a first hybrid period and a second hybrid period each alternately including a first AC period in which an AC current is supplied to the discharge lamp and a first DC period in which a DC current with a first polarity is supplied to the discharge lamp, and
wherein the control unit
in the first hybrid period, is configured to change a ratio of length of the first DC period to length of the first AC period to be increased, and
in the second hybrid period, is configured to change a ratio of the length of the first AC period to the length of the first DC period to be increased.

2. The discharge lamp driving device according to claim 1 ,
wherein the control unit is configured to change the length of the first DC period to be increased in the first hybrid period.

3. The discharge lamp driving device according to claim 1 ,
wherein the control unit is configured to change the length of the first AC period to be increased in the second hybrid period.

4. The discharge lamp driving device according to claim 1 ,
wherein, in the first hybrid period, the length of the first DC period is equal to or larger than the length of the first AC period.

5. The discharge lamp driving device according to claim 1 ,
wherein, in the second hybrid period, the length of the first AC period is equal to or larger than the length of the first DC period.

6. The discharge lamp driving device according to claim 1 ,
wherein the second hybrid period is provided sequentially right after the first hybrid period.

7. The discharge lamp driving device according to claim 1 ,
wherein a period initially provided and a period provided last in the first hybrid period are the first DC period, and
wherein a period initially provided and a period provided last in the second hybrid period are the first AC period.

8. The discharge lamp driving device according to claim 1 ,
wherein the discharge lamp driving device is configured to provide a third hybrid period and a fourth hybrid period each alternately including a second AC period in which an AC current is supplied to the discharge lamp and a second DC period in which a DC current with a second polarity opposite to the first polarity is supplied to the discharge lamp, and
wherein the control unit
in the third hybrid period, is configured to change a ratio of length of the second DC period to length of the second AC period to be increased, and
in the fourth hybrid period, is configured to change a ratio of the length of the second AC period to the length of the second DC period to be increased.

9. The discharge lamp driving device according to claim 8 ,
wherein the discharge lamp driving device is configured to alternately provide
a first period composed of the first hybrid period and the second hybrid period, the second hybrid period provided sequentially right after the first hybrid period, and
a second period composed of the third hybrid period and the fourth hybrid period, the fourth hybrid period provided sequentially right after the third hybrid period.

10. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 1 ;
a light modulation device configured to modulate light emitted from the discharge lamp according to an image signal; and
a projection optical system configured to project light modulated by the light modulation device.

11. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 2 ;
a light modulation device configured to modulate light emitted from the discharge lamp according to an image signal; and
a projection optical system configured to project light modulated by the light modulation device.

12. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 3 ;
a light modulation device configured to modulate light emitted from the discharge lamp according to an image signal; and
a projection optical system configured to project light modulated by the light modulation device.

13. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 4 ;
a light modulation device configured to modulate light emitted from the discharge lamp according to an image signal; and
a projection optical system configured to project light modulated by the light modulation device.

14. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 5 ;
a light modulation device configured to modulate light emitted from the discharge lamp according to an image signal; and
a projection optical system configured to project light modulated by the light modulation device.

15. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 6 ;
a light modulation device configured to modulate light emitted from the discharge lamp according to an image signal; and
a projection optical system configured to project light modulated by the light modulation device.

16. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 7 ;
a light modulation device configured to modulate light emitted from the discharge lamp according to an image signal; and
a projection optical system configured to project light modulated by the light modulation device.

17. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 8 ;
a light modulation device configured to modulate light emitted from the discharge lamp according to an image signal; and
a projection optical system configured to project light modulated by the light modulation device.

18. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 9 ;
a light modulation device configured to modulate light emitted from the discharge lamp according to an image signal; and
a projection optical system configured to project light modulated by the light modulation device.

19. A discharge lamp driving method for supplying a driving current to a discharge lamp provided with a first electrode and a second electrode and driving the discharge lamp, the method comprising:
supplying the discharge lamp with the driving current having a first hybrid period and a second hybrid period each alternately including a first AC period in which an AC current is supplied to the discharge lamp and a first DC period in which a DC current with a first polarity is supplied to the discharge lamp,
wherein in the first hybrid period, a ratio of length of the first DC period to length of the first AC period is changed to be increased, and
wherein in the second hybrid period, a ratio of the length of the first AC period to the length of the first DC period is changed to be increased.

Assignees

• Seiko Epson Corp

Inventors

• Yokoo Tomohiro

Classifications

• H05B41/36

  Controlling · CPC title

• H04N9/3155 Primary

  for controlling the light source (light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406) · CPC title

• H05B41/24

  in which the lamp is fed by high frequency AC {, or with separate oscillator frequency} (H05B41/26 takes precedence) · CPC title

• G03B21/2026 Primary

  Gas discharge type light sources, e.g. arcs · CPC title

• H05B41/02

  Details · CPC title