JP2604124Y2 - Screen projection TV - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen projection television, and more particularly to a screen projection television having a longer light source replacement period.

[0002]

2. Description of the Related Art FIG. 6 shows an example of the structure of a conventional screen projection television. Light emitted from a light source 11 shown in the figure is reflected by a mirror 6, and ultraviolet and infrared rays are cut off by a filter 7, and is incident on a dichroic mirror 5.

The dichroic mirror 5 reflects red light and green light in incident light and transmits blue light. The blue light transmitted through the dichroic mirror 5 is reflected by the mirror 3 and condensed by the field lens 13, and then enters the B-LCD 8, which is a blue image plane.

Then, the blue light is transmitted in the form of a blue image and further transmitted through the dichroic mirror 2 to reach the dichroic mirror 1.

On the other hand, the red light and the green light reflected by the dichroic mirror 5 reach the dichroic mirror 4, where the red light is reflected and the green light is transmitted. The reflected red light is condensed by the field lens 13 and then enters the R-LCD 10 which is a red image surface. Then, the red light is transmitted in the form of a red image, and is further reflected by the dichroic mirror 2 and reaches the dichroic mirror 1.

The green light transmitted through the dichroic mirror 4 is condensed by a field lens 13 and then enters a G-LCD 9 which is a green image plane. Then, the green light transmits in a green image shape, is reflected by the mirror 3 and reaches the dichroic mirror 1.

[0007] In this manner, the collected blue, red and green image-like lights are combined by the dichroic mirror 1 and magnified and projected by the projection lens 12 to the screen 1.
5 is imaged.

The light source used here is required to have good luminous efficiency and high color temperature, and halogen lamps, xenon lamps, metal halide lamps and the like are generally used.

[0009]

The light source used in the above-mentioned screen projection type television is required to have a high luminous efficiency and a high color temperature, and has a lifetime of several thousand hours, which is extremely shorter than that of a CRT. In addition, xenon lamps and metal halide lamps are high-pressure discharge lamps, and are provided with a lighting device that generates several thousand volts, and there is a danger in replacing the light source.

Therefore, there is a problem in that the replacement of the light source is performed by a specialized engineer and the cost is high, and if the frequency of replacement is high, the running cost of the apparatus is high.

The present invention has been made in view of the above points, and an object of the present invention is to provide a screen projection television in which the frequency of light source replacement is reduced and the running cost is reduced.

[0012]

SUMMARY OF THE INVENTION A screen projection television according to the present invention includes a light source, an image surface that transmits light emitted from the light source and emits an image, and a light source that emits light from the image surface. In a screen projection type television configured by a projection lens for enlarging and projecting an image on a screen, one light source is arranged so that radiated light reaches the image plane, and a mirror is positioned on an optical path between the light source and the image plane. And a position evacuated from the position, so that when the mirror is at a position on the optical path between the light source and the image surface, the emitted light is reflected by the mirror and emitted to the image surface. Placing the other light source on the same plane as the one light source,
The light source is selected and used by the movement of the mirror.

[0013]

According to the screen projection television of the invention,
Since a plurality of light sources are incorporated and these light sources can be used while being switched, the period of light source replacement becomes longer.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A screen projection television as an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the first of the present invention.
1 shows a structure of a screen projection type television which is a reference example.
Reference numeral 16 shown in the figure is a turntable, which is rotatably held about an axis O.

A gear is provided around the turntable 16 and meshes with a gear provided on the shaft of the drive motor 17.

The turntable 16 further includes light sources 11 and 14.
And 18 are fixed so as to face outward, and the light detection holes 20 are provided by the number of light sources. Reference numeral 19 denotes a light detection switch which sandwiches the light detection hole 20 from above and below, and detects that each light source is at a position corresponding to the mirror 6.

A light source is selected by a control device (not shown), a light detection switch 19 and a drive motor 17,
A light source located at a position facing the mirror 6 is turned on by a lighting circuit (not shown).

Light emitted from one of the light sources selected in this way is reflected by the mirror 6 and enters the filter 7. The path of the light thereafter is the same as the conventional one shown in FIG.

The light sources 11, 14 and 18 can be selected one by one until the life of each light source has expired.
There is a method in which the power source is switched every time the main power switch is turned on, and each power source is used equally.

In the former case, each light source can be used until the end of its life, but there is an inconvenience that when the life of the last power supply has expired, the device cannot be used until the power supply is replaced.

FIGS. 2 and 3 show the structure of a screen projection type television according to a second embodiment of the present invention. Reference numeral 16 shown in the figure is a turntable, which is rotatably supported on the frame around the axis O. A gear is provided around the turntable 16 and meshes with a gear provided on the shaft of the drive motor 17.

The mirror 6 is fixed to the turntable 16 and rotates together with the turntable 16. Switches 21 and 22 are fixed to the frame, and detect two rotational positions of the turntable 16 shown in FIGS. 2 and 3. The light sources 11 and 14 are fixed to the frame toward the mirror 6,
At the two rotation positions of the turntable 16, the mirror 6
And 14.

A control device (not shown) and switches 21 and
A light source is selected by the drive motor 22 and the drive motor 17,
A light source facing the mirror 6 is turned on by a lighting circuit (not shown).

Light emitted from one of the light sources selected in this way is reflected by the mirror 6 and enters the filter 7. The path of the light thereafter is the same as the conventional one shown in FIG. The method of selecting the light sources 11 and 14 is the same as in the first embodiment.

FIGS. 4 and 5 show the structure of a screen projection television according to an embodiment of the present invention. Reference numeral 16 shown in the figure is a turntable, which is rotatably supported by the frame.
A gear is provided around the turntable 16 and meshes with a gear provided on the shaft of the drive motor 17.

The mirror 6 is fixed to the turntable 16 and moves together with the turntable 16. A light detection hole 20 is provided in the turntable 16. Reference numerals 19 and 23 denote light detection switches which detect the two rotational positions of the turntable 16 shown in FIGS. 4 and 5 by sandwiching the light detection hole 20 from above and below.

The light source 14 is fixed to the frame toward the filter 7, and the emitted light reaches the filter 7 when the turntable 16 is in the rotation position shown in FIG.

The light source 11 is fixed to the frame toward the mirror 6, and when the turntable 16 is in the rotational position shown in FIG.
Leads to.

A light source is selected by a control device (not shown), the light detection switches 19 and 23, and the drive motor 17, and a light source that causes the radiated light to reach the filter 7 is turned on by a lighting circuit (not shown). You.

Light emitted from any one of the light sources thus selected enters the filter 7, and the light path thereafter is the same as that of the conventional light source shown in FIG. Light source 1
The method of selecting 1 and 14 is the same as in the first embodiment.

[0031]

According to the screen projection type television of the present invention, a plurality of light sources can be switched and used, so that long-time use is possible without replacing the light sources. Also, since the frequency of light source replacement is reduced, the running cost is reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a screen projection television as a first reference example of the present invention.

FIG. 2 is a diagram showing a structure of a screen projection television as a second reference example of the present invention.

FIG. 3 is a view showing another operation state of the reference example.

FIG. 4 is a diagram showing a structure of a screen projection type television which is an embodiment of the present invention.

FIG. 5 is a view showing another operation state of the embodiment.

FIG. 6 is a diagram showing a structure of a conventional screen projection television.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 dichroic mirror 2 dichroic mirror 3 mirror 4 dichroic mirror 5 dichroic mirror 6 mirror 7 filter 8 B-LCD 9 G-LCD 10 R-LCD 11 light source 12 projection lens 13 field lens 14 light source 15 screen 16 turntable 17 drive motor 18 19 light detection switch 20 light detection hole 21 switch 22 switch 23 light detection switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04N 5/74 G09F 9/00 G09G 3 / 18,3 / 36 G03B 21 / 14,21 / 132

Claims (1)

(57) [Scope of request for utility model registration] 1. A light source, an image surface which transmits light emitted from the light source and emits the image in an image form, and a projection lens which enlarges and projects the light emitted from the image surface to form an image on a screen. In a screen projection type television, one light source is arranged so that radiated light reaches the image plane, and a mirror is movably arranged at a position on the optical path between the light source and the image plane and a position retracted from the position. Then, when the mirror is at a position on the optical path between the light source and the image plane, the other light source is coplanar with the one light source so that emitted light is reflected by the mirror and emitted to the image plane. Place,
A screen projection television configured to select and use the light source by movement of the mirror.