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

Patent metadata

Field	Value
Publication number	US-9872370-B2
Application number	US-201615355960-A
Country	US
Kind code	B2
Filing date	Nov 18, 2016
Priority date	Oct 11, 2013
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A discharge lamp driving device includes: a discharge lamp driving unit which supplies drive power to a discharge lamp; and a control unit which controls the discharge lamp driving unit according to a waveform of the drive power. The waveform has n launching periods and a low-power mode lighting period. The n launching periods include a first launching period in which the drive power increases toward refresh power that is equal to or above drive power in a low-power mode and equal to or below rated power, and (n−1) launching periods in which the drive power is maintained at the refresh power. The control unit, in an x-th launching period, supplies the discharge lamp with a drive current having a drive frequency equal to or below a drive frequency of a drive current supplied to the discharge lamp in an (x−1)th launching period.

First claim

What is claimed is:

1. A discharge lamp driving device comprising:
a discharge lamp driving unit configured to supply drive power to a discharge lamp; and
a control unit configured to control the discharge lamp driving unit;
wherein the control unit is configured to provide a launching period from a start of lighting of the discharge lamp to a predetermined time and a stationary lighting period provided after the launching period, the stationary lighting period in which a first drive power is supplied to the discharge lamp,
the launching period include a first launching period in which the drive power supplied to the discharge lamp increases toward a second drive power larger than the first drive power and a second launching period in which the second drive power is supplied to the discharge lamp,
a drive frequency of drive current supplied to the discharge lamp in the second launching period is lower than a drive frequency of the drive current supplied to the discharge lamp in the first launching period,
the control unit is configured to perform a mode in which a drive power lower than a rated power of the discharge lamp is supplied to the discharge lamp in the stationary lighting period, and
the first drive power is the drive power in the mode.

2. The discharge lamp driving device according to claim 1 , wherein the control unit configured to detect a degree of deterioration of the discharge lamp by referring to an inter-electrode voltage of the discharge lamp in the stationary lighting period.

3. The discharge lamp driving device according to claim 2 , wherein the control unit is configured to refer to the inter-electrode voltage in the first launching period and estimate the inter-electrode voltage in the stationary lighting period on the basis the referred to inter-electrode voltage.

4. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 3 ;
a light modulation element configured to modulate light emitted from the discharge lamp, according to a video signal; and
a projection system configured to project the light modulated by the light modulation element.

5. The discharge lamp driving device according to claim 2 , wherein the control unit is configured to read out the inter-electrode voltage referred to and stored at the time of previous lighting of the discharge lamp, at the time of next lighting of the discharge lamp, and estimate the inter-electrode voltage in the stationary lighting period on the basis of the read out inter-electrode voltage.

6. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 5 ;
a light modulation element configured to modulate light emitted from the discharge lamp, according to a video signal; and
a projection system configured to project the light modulated by the light modulation element.

7. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 2 ;
a light modulation element configured to modulate light emitted from the discharge lamp, according to a video signal; and
a projection system configured to project the light modulated by the light modulation element.

8. The discharge lamp driving device according to claim 1 , wherein the drive frequency in the first launching period is equal to or higher than 500 Hz.

9. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 8 ;
a light modulation element configured to modulate light emitted from the discharge lamp, according to a video signal; and
a projection system configured to project the light modulated by the light modulation element.

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

11. A discharge lamp driving device comprising:
a discharge lamp driving unit configured to supply drive power to a discharge lamp; and
a control unit configured to control the discharge lamp driving unit;
wherein the control unit is configured to provide a launching period from a start of lighting of the discharge lamp to a predetermined time and a stationary lighting period provided after the launching period, the stationary lighting period in which a first drive power is supplied to the discharge lamp,
the launching period include a first launching period in which the drive power supplied to the discharge lamp increases toward a second drive power larger than the first drive power and a second launching period in which the second drive power is supplied to the discharge lamp,
a drive frequency of drive current supplied to the discharge lamp in the second launching period is lower than a drive frequency of the drive current supplied to the discharge lamp in the first launching period, and the drive current supplied in the second launching period intermittently includes a second waveform pattern having a higher load provided to electrodes of the discharge lamp than a load in a first waveform pattern that is a basic waveform pattern of the drive current supplied to the discharge lamp in the launching period.

12. The discharge lamp driving device according to claim 11 , wherein the control unit configured to adjust at least one of an insertion time of the second waveform pattern, an insertion interval of the second waveform pattern, a number of times of insertion of the second waveform pattern, and a configuration of the second waveform pattern, according to a degree of deterioration of the discharge lamp.

13. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 12 ;
a light modulation element configured to modulate light emitted from the discharge lamp, according to a video signal; and
a projection system configured to project the light modulated by the light modulation element.

14. The discharge lamp driving device according to claim 11 , wherein the second waveform pattern includes one of a drive current pattern having a drive frequency equal to or lower than 500 Hz and a drive current pattern combining DC driving and AC driving.

15. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 14 ;
a light modulation element configured to modulate light emitted from the discharge lamp, according to a video signal; and
a projection system configured to project the light modulated by the light modulation element.

16. A projector comprising:
a discharge lamp configured to emit light;
the discharge lamp driving device according to claim 11 ;
a light modulation element configured to modulate light emitted from the discharge lamp, according to a video signal; and
a projection system configured to project the light modulated by the light modulation element.

17. A discharge lamp driving method for supplying a drive power to a discharge lamp and driving the discharge lamp, the method comprising:
supplying the discharge lamp with the drive power including a launching period from a start of lighting of the discharge lamp to a predetermined time and a stationary lighting period provided after the launching period, the stationary lighting period in which a first drive power is supplied

Assignees

• Seiko Epson Corp

Inventors

• Nakagomi Yoichi
• Suzuki Junichi

Classifications

• H05B41/382

  during the transitional start-up phase · CPC title

• H04N9/3167

  for polarizing the light beam (polarizing optical systems per se G02B27/28) · CPC title

• H04N9/3155

  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

• H05B41/16

  in which the lamp is fed by DC or by low-frequency AC, e.g. by 50 cycles/sec AC {, or with network frequencies} · CPC title

• H04N9/3197

  using light modulating optical valves · CPC title