POWER SOURCE CIRCUIT AND PROJECTION DISPLAY DEVICE

• US 20100315845A1
• Filed: 06/08/2010
• Published: 12/16/2010
• Est. Priority Date: 06/16/2009
• Status: Abandoned Application

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Tsutsumi, Kouichi, Urayama, Takeru, Kotani, Kazunori
• Application Number:
  US12/795,866
• Publication Number:
  US 20100315845A1
• Time in Patent Office: Days
• US Class Current: 363/37
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/33561 having more than one ouput with independent control
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10

Abstract

A power source circuit includes a DC voltage generating section which rectifies and smoothes an input AC voltage to generate a DC voltage; a switching regulator which converts the DC voltage into an AC voltage; a transformer which lowers the AC voltage; a first switch connected between a secondary winding of the transformer, and a load; and a control section which controls on/off of the switch. The control section controls the first switch to turn off the first switch at a time of a waiting mode.

Claims

1. A power source circuit comprising:

a DC voltage generating section which rectifies and smoothes an input AC voltage to generate a DC voltage;

a switching regulator which converts the DC voltage into an AC voltage;

a transformer which lowers the AC voltage;

a first switch connected between a secondary winding of the transformer, and a load; and

a control section which controls on/off of the switch, wherein

the control section controls the first switch to turn off the first switch at a time of a waiting mode.

2. The power source circuit according to claim 1, wherein

an electric power supply line to the control section is branched from a portion between the secondary winding of the transformer, and the first switch.

3. The power source circuit according to claim 1, wherein

the switching regulator is selectively set to a first operation mode, and a second operation mode of low output and low electric power loss, as compared with the first operation mode, and

the control section controls the switching regulator to set the switching regulator to the second operation mode at the time of the waiting mode.

4. The power source circuit according to claim 1, wherein

the DC voltage generating section includes a power factor improving circuit, and

the control section controls the power factor improving circuit to turn off the power factor improving circuit at the time of the waiting mode.

5. The power source circuit according to claim 1, further comprising:

a second switch connected between the DC voltage generating section, and the load, wherein

the control section controls the second switch to turn off the second switch at the time of the waiting mode.

6. A projection display device comprising:

a power source circuit;

a circuit section which is supplied an electric power by the power source circuit;

an optical engine which generates modulated light based on an image signal; and

a projection optical system which enlarges and projects the modulated light onto a projection plane, wherein

the power source circuit includes;

a DC voltage generating section which rectifies and smoothes an input AC voltage to generate a DC voltage;

a switching regulator which converts the DC voltage into an AC voltage;

a transformer which lowers the AC voltage;

a first switch connected between a secondary winding of the transformer, and a load; and

a control section which controls on/off of the switch, wherein

the control section controls the first switch to turn off the first switch at a time of a waiting mode.

7. The projection display device according to claim 6, wherein

an electric power supply line to the control section is branched from a portion between the secondary winding of the transformer, and the first switch.

8. The projection display device according to claim 6, wherein

the switching regulator is selectively set to a first operation mode, and a second operation mode of low output and low electric power loss, as compared with the first operation mode, and

the control section controls the switching regulator to set the switching regulator to the second operation mode at the time of the waiting mode.

9. The projection display device according to claim 6, wherein

the DC voltage generating section includes a power factor improving circuit, and

the control section controls the power factor improving circuit to turn off the power factor improving circuit at the time of the waiting mode.

10. The projection display device according to claim 6, further comprising:

a second switch connected between the DC voltage generating section, and the load, wherein

the control section controls the second switch to turn off the second switch at the time of the waiting mode.