Liquid crystal display device and liquid crystal display system

• US 8,054,412 B2
• Filed: 02/21/2007
• Issued: 11/08/2011
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kadowaki, Shinichi, Itoh, Tatsuo, Mizushima, Tetsuro, Yamamoto, Kazuhisa
• Primary Examiner(s): Wong; Tina
• Application Number:
  US12/280,873
• Publication Number:
  US 20090066879A1
• Time in Patent Office: 1,721 Days
• Field of Search: None
• US Class Current: 349/86
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 1/133622 Colour sequential illumination
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence

Abstract

A light source portion having laser light sources emitting red light, green light, and blue light and conventionally disposed integrally with the liquid crystal display panel is spatially separated from the liquid crystal display panel. Accordingly, the power supply, the optical system, and the heat source are incorporated into the light source portion and are thereby completely separated from the liquid crystal display panel. A laser beam emitted from the light source portion is guided to the liquid crystal display panel via a fiber. In this manner, it is possible to achieve a liquid crystal display device capable of significantly reducing the liquid crystal display panel in thickness and weight.

Claims

1. A liquid crystal display device comprising:

a light source portion comprising a red LD light source that emits red laser light, a blue LD light source that emits blue laser light, a green SHG-LD light source that emits infrared laser light, and a laser light source drive circuit portion that drives the red LD light source, the blue LD light source and the green SHG-LD light source;

a liquid crystal display panel portion including a liquid crystal display panel that displays an image thereon by applying a voltage to liquid crystals, and

a fiber that guides the red laser light, the blue laser light, and the infrared laser light, emitted from the red LD light source, the blue LD light source and the green SHG-LD light source of the light source portion, to the liquid crystal display panel portion, wherein;

the fiber is formed in such a manner that the light source portion and the liquid crystal display panel portion are disposed to be spatially separated,

the liquid crystal display panel portion includes an SHG element that converts a portion of the infrared laser light guided by the fiber to green laser light, includes a dichroic mirror that separates a remaining portion of the infrared laser light not converted to the green laser light by the SHG element, and includes a photoelectric conversion element that converts into power the remaining portion of the infrared laser light separated by the dichroic mirror,

the liquid crystal display panel portion is driven by the power, and

the laser light source drive circuit portion determines a light intensity of the infrared laser light emitted from the green SHG-LD light source, based on a required drive power of the liquid crystal display panel portion and based on a required output intensity of the green laser light.

2. The liquid crystal display device according to claim 1, wherein:

the fiber is formed to inhibit conduction of heat generated by a laser light.

3. The liquid crystal display device according to claim 1, wherein:

the green SHG-LD light source is driven by a pulse train using a Q switch.

4. The liquid crystal display device according to claim 1, wherein:

the fiber is a multi-mode fiber.

5. The liquid crystal display device according to claim 1, wherein:

the fiber is a double-clad fiber.

6. The liquid crystal display device according to claim 1, wherein:

the liquid crystal display panel portion has a light guide plate that allows a laser light coming incident on the liquid crystal display panel portion by propagating through the fiber to come incident thereon from one end face portion.

7. The liquid crystal display device according to claim 1, wherein:

the liquid crystal display panel portion is of a wall-hung type.

8. The liquid crystal display device according to claim 1, wherein:

the light source portion is of a floor-stand type.

9. The liquid crystal display device according to claim 8, wherein:

at least one of the red LD light source, the blue LD light source and the green SHG-LD light source is disposed on a bottom surface of the light source portion and heat generated when emitting laser light is released from the bottom surface of the light source portion.

10. A liquid crystal display device comprising:

a light source portion comprising a red LD light source that emits red laser light, a blue LD light source that emits blue laser light, a green SHG-LD light source including an infrared laser light source emitting infrared laser light, a SHG element that converts a portion of the infrared laser light to green laser light, and a drive signal generation portion that converts an inputted video signal to a liquid crystal drive signal and emits a driving infrared laser light onto which a modulation signal of the liquid crystal drive signal is superimposed;

a liquid crystal display panel portion including a liquid crystal display panel that displays an image thereon by applying a voltage to liquid crystals; and

a fiber that guides, from the light source portion to the liquid crystal display panel portion, the red laser light, the green laser light, the blue laser light, a remaining portion of the infrared laser light not converted to the green laser light by the SHG element, and the driving infrared laser light emitted from the drive signal generation portion, wherein;

the fiber is formed in such a manner that the light source portion and the liquid crystal display panel portion are disposed to be spatially separated,

the liquid crystal display panel portion

separates the remaining portion of the infrared laser light not converted to the green laser light, the driving infrared laser light emitted from the drive signal generation portion and red-green-blue laser light including the red laser light, the green laser light and the blue laser light, as guided by the fiber,

uses the red-green-blue laser light as backlight illumination for the liquid crystal display panel,

converts the driving infrared laser light emitted from the drive signal generation portion to the liquid crystal drive signal to drive liquid crystals of the liquid crystal display panel, and

includes a photoelectric conversion element that converts into power the remaining portion of the infrared laser light not converted to the green laser light, and

the liquid crystal display panel is driven by the power.

11. A liquid crystal display system, including:

a plurality of liquid crystal display units, each of the plurality of liquid crystal display units including a respective liquid crystal display panel and a respective light guide member that guides light to the respective liquid crystal display panel; and

a laser light source unit that supplies a laser beam to each of the plurality of liquid crystal display units to illuminate the respective liquid crystal display panel of each of the plurality of liquid crystal display units,

wherein the laser light source unit includes;

a laser light source portion comprising a red LD light source that emits red laser light, a blue LD light source that emits blue laser light, a green SHG-LD light source that emits infrared laser light, and a laser light source drive circuit portion that drives the red LD light source, the blue LD light source and the green SHG-LD light source;

a control portion that controls the laser light source portion;

an optical fiber portion that guides the red laser light, the blue laser light, and the infrared laser light, emitted from the laser light source portion, to each of the plurality of liquid crystal display units; and

a plurality of optical connectors disposed in a one-to-one correspondence with the plurality of liquid crystal display units and capable of connecting the optical fiber portion and a respective fiber to each of the plurality of liquid crystal display units,

wherein the optical fiber portion is formed in such a manner that the laser light source portion and the plurality of liquid crystal display units are disposed to be spatially separated,

wherein each of the plurality of liquid crystal display units includes an SHG element that converts a portion of the infrared laser light guided by the optical fiber portion to green laser light, includes a dichroic mirror that separates a remaining portion of the infrared laser light not converted to the green laser light by the SHG element, and includes a photoelectric conversion element that converts into power the remaining portion of the infrared laser light separated by the dichroic mirror,

wherein the respective liquid crystal display panel of each of the plurality of liquid crystal display units is driven by the power, and

wherein the laser light source drive circuit portion determines a light intensity of the infrared laser light emitted from the green SHG-LD light source, based on a required drive power of the respective liquid crystal display panel of each of the plurality of liquid crystal display units and based on a required output intensity of the green laser light.

12. The liquid crystal display system according to claim 11, wherein:

the optical fiber portion is formed to inhibit conduction of heat generated by the laser beam.

13. The liquid crystal display system according to claim 11, wherein:

the control portion has a light output control circuit that controls a light intensity of the laser beam supplied from the laser light source unit; and

the light output control circuit sets the light intensity of the laser beam supplied from the laser light source unit according to each of the plurality of liquid crystal display units to which the laser light source unit needs to supply the laser beam.

14. The liquid crystal display system according to claim 13, wherein:

each respective liquid crystal display unit of the plurality of liquid crystal display units transmits a start-up signal to an optical connector of the plurality of optical connectors at a time of start-up of the respective liquid crystal display unit; and

each respective optical connector of the plurality of optical connectors transmits the start-up signal and a connector identification signal to identify the respective optical connector to the control portion upon receipt of the start-up signal from a liquid crystal display unit of the plurality of liquid crystal display units.

15. The liquid crystal display system according to claim 14, wherein:

upon receipt of the start-up signal and the connector identification signal from the respective optical connector, the control portion identifies a liquid crystal display unit, of the plurality of liquid crystal display units, that is started according to the start-up signal and the connector identification signal, and transmits the laser beam supplied from the laser light source unit to the identified liquid crystal display unit.

16. The liquid crystal display system according to claim 15, wherein:

the start-up signal contains a display start signal requesting the identified liquid crystal display unit to start a display and a panel identification signal specifying characteristics of the respective liquid crystal display panel of the identified liquid crystal display unit.

17. The liquid crystal display system according to claim 16, wherein:

the control portion sets the light intensity of the laser beam supplied from the laser light source according to the panel identification signal by driving the light output control circuit.

18. The liquid crystal display system according to claim 11, wherein:

the laser light source unit further has an optical coupling mechanism portion that combines a plurality of laser beams supplied from the laser light source portion into one laser beam.

19. The liquid crystal display system according to claim 18, wherein:

the optical fiber portion is formed of a bundle of a plurality of optical fibers;

all one end portions of the optical fibers are disposed on a side of the laser light source portion and other end portions of the optical fibers are disposed for the optical connectors in a one-to-one correspondence; and

the laser beam outputted from the optical coupling mechanism portion is guided to the plurality of liquid crystal display units via the optical fibers.

20. The liquid crystal display system according to claim 19, wherein:

the laser light source unit further includes a light propagation portion disposed between the optical coupling mechanism portion and the optical fiber portion and capable of propagating the laser beam outputted from the optical coupling mechanism portion to an arbitrary optical fiber among the optical fibers; and

the light propagation portion includes at least one of an optical element that splits the laser beam outputted from the optical coupling mechanism portion and an optical element that switches optical paths.

21. The liquid crystal display system according to claim 11, wherein:

the optical fiber portion is formed of a bundle of a plurality of optical fibers;

all one end portions of the optical fibers are disposed on a side of the laser light source portion and other end portions of the optical fibers are disposed for the optical connectors in a one-to-one correspondence;

the laser light source unit is a multi-luminous light source that emits a laser beam having a plurality of peak wavelengths; and

the laser light source unit further has a variable demultiplexer provided between the laser light source portion and the optical fiber portion to demultiplex the laser beam emitted from the multi-luminous light source to respective peak wavelengths that are propagated to the optical fibers pre-assigned to the respective peak wavelengths.

22. The liquid crystal display system according to claim 11, wherein:

the laser light source unit is a multi-luminous light source that emits a laser beam having a plurality of peak wavelengths; and

the laser light source unit further has a variable demultiplexer provided to each of the plurality of optical connectors to demultiplex the laser beam emitted from the multi-luminous light source into respective peak wavelengths for the laser beam emitted from the multi-luminous at a pre-assigned peak wavelength alone to be propagated to the fiber.

23. The liquid crystal display system according to claim 11, wherein:

each respective liquid crystal display unit of the plurality of liquid crystal display units further includes a respective light guide plate for illumination that illuminates a space in which the respective liquid crystal display unit is installed; and

the respective light guide plate for illumination is connected to the optical connector corresponding to the respective liquid crystal display unit installed in the space illuminated by the respective light guide plate for illumination via an optical fiber for illumination.

24. A liquid crystal display system comprising:

a plurality of liquid crystal display units, each of the plurality of liquid crystal display units including a respective liquid crystal display panel and a respective light guide member that guides light to the respective liquid crystal display panel; and

a laser light source unit that supplies a laser beam to each of the plurality of liquid crystal display units to illuminate the respective liquid crystal display panel of each of the plurality of liquid crystal display units,

wherein the laser light source unit includes;

a laser light source portion comprising a red LD light source that emits red laser light, a blue LD light source that emits blue laser light, a green SHG-LD light source including an infrared laser light source emitting infrared laser light, a SHG element that converts a portion of the infrared laser light to green laser light, a laser light source drive circuit portion that drives the red LD light source, the blue LD light source and the green SHG-LD light source, and a drive signal generation portion that converts an inputted video signal to a liquid crystal drive signal and emits a driving infrared laser light onto which a modulation signal of the liquid crystal drive signal is superimposed;

a control portion that controls the laser light source portion;

an optical fiber portion that guides, from the laser light source portion to each of the plurality of liquid crystal display units, the red laser light, the green laser light, the blue laser light, a remaining portion of the infrared laser light not converted to the green laser light by the SHG element, and the driving infrared laser light emitted from the drive signal generation portion; and

a plurality of optical connectors disposed in a one-to-one correspondence with the plurality of liquid crystal display units and capable of connecting the optical fiber portion and a respective fiber to each of the plurality of liquid crystal display units,

wherein the optical fiber portion is formed in such a manner that the laser light source portion and the plurality of liquid crystal display units are disposed to be spatially separated,

wherein each of the plurality liquid crystal display units;

separates the remaining portion of the infrared laser light not converted to the green laser light, the driving infrared laser light emitted from the drive signal generation portion, and red-green-blue laser light including the red laser light, the green laser light and the blue laser light, as guided by the optical fiber portion;

uses the red-green-blue laser light as backlight illumination for the respective liquid crystal display panel;

converts the driving infrared laser light emitted from the drive signal generation portion to the liquid crystal drive signal to drive liquid crystals of the respective liquid crystal display panel; and

includes a photoelectric conversion element that converts into power the remaining portion of the infrared laser light not converted to the green laser light, and

wherein the respective liquid crystal display panel of each of the plurality of liquid crystal units is driven by the power.