JP2500148Y2 - Video projector equipment - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video projector device.

[0002]

2. Description of the Related Art As shown in FIG. 4, a screen of a conventional video projector device is composed of a Fresnel lens 21 and a lenticular lens 24. The Fresnel lens 21 has a substantially saw-toothed surface including a rising surface 22 and an inclined surface 23. The tooth portion 27 is formed in a ring shape, and the back surface side of the same surface has a flat shape. The lenticular lens 24 has projections 25 having a substantially semicircular cross section and flat portions 26 alternately arranged on the front surface, and has a flat shape on the back surface side. Then, the back side of the lenticular lens 24 and the Fresnel lens 21
The substantially sawtoothed tooth portion 27 side is overlapped. Then, in order to improve the contrast of the screen, a coloring treatment or a colored light-shielding plate is mounted on the flat surface portion 26 of the lenticular lens 24 that is superposed together.

According to the above construction, the colored portion or the colored shading plate is provided on the flat portion 26 provided for improving the contrast of the screen surface. It has the effect of penetrating inside and reducing the reflection of light rays from the viewer side to the screen surface, but with that effect the aperture ratio of the screen is reduced and the projection light emitted from the projection tube (not shown) is colored. There is a problem that the brightness of the screen surface is remarkably reduced by the treatment or by hitting the colored shading plate and reflecting the light internally.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a video projector device that reduces the decrease in the brightness of the screen surface and improves the contrast.

[0005]

In order to solve the above problems, according to the present invention, a Fresnel lens and a lenticular lens constituting a screen are superposed, and a substantially semicircular shape is formed on the non-overlapping surface of the superposed lenticular lens. Incidents from the direction of the Fresnel lens are provided by providing columnar protrusions in series, attaching a light shielding member having a substantially wedge-shaped cross section to each valley between adjacent protrusions, and providing a reflection film on the attachment surface wall of the light shielding member. The reflective film is characterized in that the light does not exceed the critical angle.

[0006]

According to the above construction, since the incident light from the Fresnel lens direction does not exceed the critical angle on the attachment surface wall of the light shielding member attached to the lenticular lens, the light is transmitted through the Fresnel lens. The projected light hits the light shielding member and is not reflected inside, and the projected light hits the reflective film is reflected to the outside of the lenticular lens to improve the brightness of the screen surface.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a schematic configuration of a rear transmissive video projector device, and a housing 1 has a first opening 2 on the upper side of the front surface. The escutcheon 3 forms a second opening 4 that faces the first opening 2, engages the first opening 2 and the second opening 4, and is mounted on the upper front side of the housing 1. The screen 5 is composed of two types of lenses, plays a role of converting the light beam enlarged and projected by the projection lens 7 of the projection tube 6 into substantially parallel light beams, and also has a thinner Fresnel lens 13 than the lenticular lens 9. The lenticular lens 9 that plays a role of increasing the brightness on the screen 5 by giving directivity is overlapped and formed, and the overlapped lenticular lens 9 side is directed to the outside of the second opening 4 and the second opening. Attach to the inside of 4. The projection tube 6 is provided with a projection lens 7 on the front surface and corresponds to each of the three colors of red, blue, and green. Set up. The mirror 8 is made of plate glass, and is arranged on the upper rear surface of the housing 1 to reflect the image from the projection tube 6 toward the screen 5.

More specifically, FIG. 2 (a) is a cross-sectional view of essential parts and FIG.
(B) As shown in the enlarged view of part A, the lenticular lens 9 to be superposed has a substantially semi-cylindrical projection 10 continuously provided on the surface thereof, and light shielding is formed by forming a substantially wedge-shaped cross section between adjacent valleys of the projection 10. The member 11 is attached. The light shielding member 11 is formed of a black or dark blue or dark green material that does not transmit light, plays a role of improving the contrast of the surface of the screen 5, does not transmit light to the attachment surface 12, and moves toward the Fresnel lens 13 direction. The first transmitted light 18 from the critical angle 3
A reflective film 17 having an angle size not exceeding 0,
The back surface has a flat shape. On the other hand, Fresnel lens 13
Has a substantially saw-toothed portion 16 having a rising surface 14 on the front surface and inclined surfaces 15 on both ends of the rising surface 14, and has a flat shape on the back surface. Then, the back surface side of the lenticular lens 9 and the substantially sawtooth portion 16 side of the Fresnel lens 13 are overlapped.

In the above structure, the projection light emitted from the projection tube 6 passes through the plurality of inclined surfaces 15 of the Fresnel lens 13 and further reaches the lenticular lens 9,
Although the projection light that passes through the lenticular lens 9 reaches the direction of the viewer who views the screen 5, the projection light that travels in the direction of the light blocking member 11 hits the light blocking member 11 and is reflected inward so that it is transmitted to the viewer. Although the projected light to be emitted was reduced, in the present invention, the reflection film 17 is formed on the attachment surface 12 of the light shielding member 11.
As a result, the projection light is transmitted through the Fresnel lens 13 as shown by an arrow in the figure, the first transmitted light 18 is reflected by the reflection film 17, and then the second transmitted light is transmitted through the protrusion 10 of the lenticular lens 13. It becomes the transmitted light 19 and further becomes the third transmitted light 20 emitted from the protruding portion 10 in the outside air direction and reaches the viewer side. Further, even if the reflective film 17 is thin and easily transmits light, since the base material forming the light shielding member 11 is a dark color, the reflection loss of the projected light can be reduced and the brightness and contrast of the surface of the screen 5 are further improved.

Now, the critical angle 30 of the present invention is as shown in FIG.
As shown in (a), the first transmitted light 18 that has passed through the Fresnel lens 13 and reached the lenticular lens 13 is reflected by the reflection film 17 provided at the A angle 31 portion within the critical angle 30, and the second transmitted light 18 19 and reaches the end of the protrusion 10,
After that, the third transmitted light 20 refracting in the air becomes the third transmitted light 20 from the end of the protrusion 10 and reaches the viewer side. , The lenticular lens 13 as shown in FIG.
The first transmitted light 18 that has reached the position is reflected by the reflective film 17 and becomes the second transmitted light 19 that is refracted inward without reaching the end direction of the protrusion 10.

The reflective film 17 may be formed by an electrochemical treatment such as plating, sputtering or vacuum vapor deposition, or if a separate member made of resin or metal is attached instead of the electrochemical treatment, the above-mentioned structure is obtained. It holds.

[0012]

As described above, according to the present invention, the Fresnel lens is provided by providing the reflecting surface of the light-shielding member attached to the lenticular lens with the reflection film having the size that the incident light from the Fresnel lens direction does not exceed the critical angle. The transmitted projection light hits the light shielding member and is not reflected inside, and the projection light hits the reflective film is reflected to the outside of the lenticular lens, reducing the decrease in the brightness of the screen surface and improving the contrast. be able to.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a schematic configuration of the present invention.

FIG. 2 is a sectional view and an enlarged view of a main part for explaining the details of the present invention.

FIG. 3 is a detailed view illustrating a critical angle of the present invention.

FIG. 4 is a cross-sectional view of an essential part for explaining the details of the conventional art.

[Explanation of reference symbols] 1 case 2 first opening 3 escutcheon 4 second opening 5 screen 6 projection tube 7 projection lens 8 mirror 9 lenticular lens 10 protrusion 11 light blocking member 12 attachment surface 13 Fresnel lens 14 rising surface 15 inclination Surface 16 Sawtooth 17 Reflective film 18 First transmitted light 19 Second transmitted light 20 Third transmitted light 30 Critical angle 31 A angle 32 B angle

Claims (4)

(57) [Scope of utility model registration request] 1. A Fresnel lens and a lenticular lens forming a screen are overlapped with each other, and a substantially semi-cylindrical projection is continuously provided on a non-overlapping surface of the lenticular lens overlapped with each other. A light shielding member having a substantially wedge-shaped cross section is attached to each valley, and a reflection film is provided on the attachment surface wall of the light shielding member so that the incident light from the Fresnel lens direction does not exceed a critical angle. A video projector device characterized by the above. 2. The video projector device according to claim 1, wherein the light-shielding member has a dark color. 3. The video projector device according to claim 1, wherein the reflection film is formed by an electrochemical treatment such as plating, sputtering or vacuum deposition. 4. The video projector device according to claim 1, wherein the reflective film is made of a separate member made of resin or metal.