CN1779560A - Rear projection screen and its optical device - Google Patents

Abstract

The invention relates to a rear projection screen and an optical device thereof, which comprises an optical element and a light absorption pattern layer, wherein one surface of the optical element is provided with a columnar convex part structure, and the columnar convex part structure comprises a first convex part and a second convex part with different curvature parameters; the light absorption pattern layer is provided with a plurality of light absorption units and is arranged on the other surface of the columnar convex part structure opposite to the optical element. The invention can eliminate the phenomenon of interference fringes (moire) which cause visual discomfort on the screen.

Description

Rear projection screen and its optical device

technical field

The present invention relates to an optical device, in particular to an optical device used to form a rear projection screen to eliminate the phenomenon of interference fringe (Moiré) on the screen that causes visual discomfort.

Background technique

With the popularization of HDTV and DVD-Player, and the development of optical technology of projection display is becoming more and more mature, large-size TV images are getting more and more attention from the market and favored by consumers.

According to different projection display methods, it can be divided into two types: rear-projection (Real-Projection) and front-projection (Front-Projection). It is called the front projection type, and vice versa, it is called the rear projection type when viewed from the rear of the screen. Today, due to the advantages of no radiation, high-definition large-screen display, and low price, rear-projection TVs have gradually become the mainstream of TV purchases.

Please refer to shown in Fig. 1, known rear projection screen 1 comprises a Fresnel lens (FresnelLens) 11 and a lenticular lens (Lanticular Lens) 12, and Fresnel lens 11 is a focusing lens, and it mainly projects the projection display The incident light is deflected to the direction perpendicular to the screen so that the light rays leave the Fresnel lens 11 parallel to each other, so that the light in the field of view can be used well, thereby improving the brightness and uniformity of the image, while the lenticular lens 12 Imaging used to provide images.

The lenticular lens 12 has a plurality of cylindrical convex portions 121 disposed on the light incident surface, and a plurality of black stripes (Black Stripes) 122 disposed on the light emitting surface. As shown in Figure 2, after the parallel light 20 leaving the Fresnel lens 11 is perpendicularly incident on the cylindrical convex part 121, the light 20 will be focused in the lenticular lens 12 and then emitted from the light-emitting surface, and the black stripes 122 on the light-emitting surface will be The non-focusing parts 123 corresponding to the cylindrical convex part 121 on the light-emitting surface are respectively accurately covered, and the black stripes 122 are made of light-absorbing materials to absorb stray light entering the cylindrical lens 12 and the environment from the viewer. Light, which in turn can reduce the influence of external light and improve the contrast of the picture.

The manufacture of the black stripes 122, as is well known in the industry, is to coat the photoresist with an appropriate thickness on the light-emitting surface of the lenticular lens 12, and then use the light source to irradiate the columnar convex part 121, and the light ray 20 of the light source will pass through the columnar convex part 121. Regularly focus and project on the photoresist, and perform positive development (or negative development) and other process steps to produce a plurality of black stripes 122. Since the columnar protrusions 121 are arranged regularly and have approximately the same height curvature, therefore Regularly arranged and equal-width black stripes 122 are formed. Due to the regular spacing between the black stripes 122, it is easy to cause interference of light when applied to a projection display system, and a phenomenon commonly known as interference fringe (Moiré) is produced visually. In addition to causing uncomfortable vision for the viewer, it also reduces the quality of the entire picture.

Based on the above, today's rear projection screen still has room for improvement, so how to provide a rear projection screen and its optical device that eliminates the phenomenon of interference fringe (Moiré) that causes visual discomfort on the screen is one of the current important issues. one.

Contents of the invention

In view of the above-mentioned problems, the object of the present invention is to provide a rear projection screen and an optical device thereof which can eliminate interference fringes.

To achieve the above object, the optical device according to the present invention includes an optical element and a light absorption pattern layer, wherein one surface of the optical element has a columnar convex structure, and the columnar convex structure includes a first layer with different curvature parameters. The convex portion and a second convex portion; the light absorbing pattern layer has a plurality of light absorbing units, and the light absorbing pattern layer is arranged on the other surface of the columnar convex portion structure opposite to the optical element.

To achieve the above object, the rear projection screen according to the present invention comprises a first optical element, a light absorbing pattern layer and a second optical element, wherein a surface of the first optical element has a columnar convex structure, and the columnar convex portion The structure includes a first protrusion and a second protrusion with different curvature parameters; the light absorption pattern layer has a plurality of light absorption units, and the light absorption pattern layer is arranged on the other surface of the columnar protrusion structure opposite to the optical element on; the second optical element is adjacent to the first optical element.

Based on the above, because the rear projection screen and its optical device according to the present invention utilize an optical element having a columnar convex structure with different curvature parameters, since the convex curvature parameters of the columnar convex structure are different, the incident light can be made Change the regular focus position, and at the same time cause the light absorption pattern layer of the light absorption unit with unequal width, so that the rear projection screen combined with this optical device can eliminate the visual discomfort caused by the irregular change of the light output range interference fringe phenomenon.

Description of drawings

FIG. 1 is a schematic perspective view showing a known rear projection screen;

FIG. 2 is a schematic sectional view showing a known rear projection screen;

3 is a schematic cross-sectional view showing an optical device according to a preferred embodiment of the present invention;

4 is a schematic cross-sectional view showing another optical device according to a preferred embodiment of the present invention;

FIG. 5 is a schematic diagram showing an optical device according to another preferred embodiment of the present invention;

6A-6E are a group of cross-sectional schematic diagrams showing yet another optical device according to a preferred embodiment of the present invention;

7 is a schematic cross-sectional view showing another optical device according to a preferred embodiment of the present invention; and

FIG. 8 is a schematic diagram showing a rear projection screen according to a preferred embodiment of the present invention.

Description of component symbols:

1 rear projection screen

11 Fresnel lens

12 lenticular lens

121 columnar convex part

122 black stripes

123 Non-focused part

2 Optical device

20 rays

21 Optical components

21A Light incident surface

21B light emitting surface

211 The first convex part

212 Second convex part

213 The third convex part

22 light absorbing pattern layer

221 light absorption unit

P focus point

P’ focus point

23 light diffusion layer

24 anti-reflection layer

3 rear projection screen

30 Second optical element

31 The first optical element

32 light absorbing pattern layer

41A Light incident surface

Detailed ways

The rear projection screen and its optical device according to preferred embodiments of the present invention will be described below with reference to related drawings, wherein the same components will be described with the same reference symbols.

Referring to FIG. 3 , the optical device 2 according to a preferred embodiment of the present invention includes an optical element 21 and a light absorption pattern layer 22 .

One surface of the optical element 21 has a columnar convex structure, which can focus the incident parallel light rays to form an image. As shown in FIG. 3 , the columnar convex structure includes a first convex portion 211 and a first There are two convex portions 212, and the curvature parameters of the first convex portion 211 and the second convex portion 212 are different. Wherein, the optical element 21 can be a cylindrical lens.

The light-absorbing pattern layer 22 is arranged on the other surface of the columnar protrusion structure opposite to the optical element 21, that is, on the light-emitting surface 21B opposite to the light-incident surface 21A of the optical element 21. As mentioned above, the light-absorbing pattern layer 22 There are a plurality of light-absorbing units 221. In the manufacturing process, the light-absorbing pattern layer 22 is formed on the light-emitting surface 21B opposite to the optical element 21 and coated with a photoresist for positive development or negative development. After being irradiated by light, the optical element The light emitted after being focused in 21 makes the photoresist exposed by the light developed and can be removed (positive developing photoresist) or still attached to the light-emitting surface 21B after development (negative developing photoresist), thus forming a plurality of The pattern layer formed by the light absorbing unit 221 has different light output ranges due to the different focus points P and P′ of the incident light in the optical element 21 , so the width of the formed light absorbing unit 211 is also different.

Based on the above, because the curvature parameters of the protrusions of the columnar protrusion structure are different, the optical device 2 with this structure is used to eliminate the difference in the light output range due to the change of the focal point position after the light is incident during the imaging process. The phenomenon of interference fringes caused by consistent spacing.

Moreover, as shown in FIG. 4 , the columnar protrusion structure of the optical device 2 according to a preferred embodiment of the present invention further includes a third protrusion 213 whose curvature parameter is different from that of the first protrusion 211 or the second protrusion. The curvature parameter of 212 is used to cause the change of the range of light exiting, so as to eliminate the effect of interference fringe. Of course, in this embodiment, the optical device 2 can further include a curvature parameter different from that of the first convex portion 211 or the second convex portion 211. Application of the curvature parameters of the convex portion 212 to the fourth convex portion, the fifth convex portion, . . . and so on. Wherein, the curvature parameters of the protrusions 211 , 212 , 213 of the columnar protrusion structure may change regularly, such as 2 times, 3 times, 6 times, etc., or may be a combination of irregular changes.

In this embodiment, the curvature parameters of the protrusions 211, 212, 213 can be changed according to whether the light incident surface 21A is not located on the same reference horizontal line (as shown in Figures 3 and 4), or according to the position of the light incident surface 41A. Changes in the curvature parameters on the same reference level (as shown in Figure 5) make the focal point where the incident light is focused to be different, and thus have different changes in the light output range.

Based on the above, the optical device 2 according to the preferred embodiment of the present invention further includes a light diffusion layer 23, which is arranged on the other surface of the columnar convex portion structure opposite to the optical element 21, however, its arrangement position, It can be formed on and covered on the light absorption pattern layer 22 (as shown in FIG. 6A ), or can be formed between the optical element 21 and the light absorption pattern layer 22 (as shown in FIG. 6B ). In addition, the optical device 2 can also be It further includes an anti-reflection layer 24, which can also be arranged on the light-absorbing pattern layer 22. As mentioned above, the setting position of the anti-reflection layer 24 can be formed on the light-absorbing pattern layer 22 and covered (as shown in FIG. 6C shown), or can be formed between the optical element 21 and the light-absorbing patterned layer 22 (as shown in FIG. 6D ), in addition, the light-diffusing layer 23 and the anti-reflection layer 24 can be combined and formed on the light-absorbing patterned layer 22 (As shown in FIG. 6E ) or between the optical element 21 and the light-absorbing pattern layer 22. With these structures, when the optical device 2 is applied to a rear projection screen, the purpose of increasing the viewing angle and light intensity can be achieved, and the rear surface can be improved. The quality of the projection screen.

Moreover, as shown in FIG. 7 , in this embodiment, the optical element 21 of the optical device 2 can be filled with light-diffusing particles, so that the optical device 2 can not only increase the viewing angle, but also make the brightness of the image more uniform.

Referring again to FIG. 8 , the rear projection screen 3 according to a preferred embodiment of the present invention includes a first optical element 31 , a light absorption pattern layer 32 and a second optical element 30 .

The first optical element 31 is the above-mentioned optical element 21, and its structure, composition and characteristics are as described above, so it will not be described in detail. In this embodiment, the second optical element 30 is adjacent to the first optical element 31, and is used The above-mentioned first optical element 31 is combined to form the rear projection screen 3, wherein the second optical element 30 is a Fresnel lens (Fresnel Lens), which deflects the light after gathering the light from the light source, so that the light that leaves the Fresnel lens The light becomes parallel to each other and enters the lenticular lens to form an image.

In summary, according to the rear projection screen and its optical device in the preferred embodiment of the present invention, the optical element (the first optical element) has a columnar convex structure with a combination of convex portions with different curvature parameters, so that after the incident light Focus points at different positions can be generated, and then the range of light output can be changed irregularly. This optical device is applied to the rear projection screen to achieve the purpose of eliminating the interference fringe effect that makes the visual uncomfortable, thereby improving the rear projection screen. quality.

The above descriptions are illustrative only, not restrictive. Any equivalent modification or change without departing from the spirit and scope of the present invention shall be included in the scope of the claims.

Claims (13)

1. optical devices is characterized in that, comprise:

One optical element, its one of the surface have a cylindrical projection structure, this cylindrical projection structure comprises one first different protuberance of curvature parameters and one second protuberance; And

One light absorbs patterned layer, and it has a plurality of light absorptive units, and this light absorbs on another surface that patterned layer is arranged at the cylindrical projection structure of this optical element relatively.

2. optical devices as claimed in claim 1 is characterized in that, this cylindrical projection structure more comprises:

One the 3rd protuberance, its curvature parameters are different from the curvature parameters of this first protuberance or this second protuberance.

3. optical devices as claimed in claim 1 is characterized in that, this optical element is a lens pillar.

4. optical devices as claimed in claim 1 is characterized in that, more comprise:

One light diffusion layer, it is arranged on another surface of the relative cylindrical projection structure of this optical element.

5. optical devices as claimed in claim 1 is characterized in that, are filled with light diffusion particulate in this optical element.

6. optical devices as claimed in claim 1 is characterized in that the sectional width of these light absorptive units is different each other.

7. a rear projection screen is characterized in that, comprises:

One first optical element, its one of the surface have a cylindrical projection structure, this cylindrical projection structure comprises one first different protuberance of curvature parameters and one second protuberance;

One light absorbs patterned layer, and it has a plurality of light absorptive units, and this light absorbs on another surface that patterned layer is arranged at the cylindrical projection structure of this optical element relatively; And

One second optical element, it is adjacent to this first optical element.

8. rear projection screen as claimed in claim 7 is characterized in that, this cylindrical projection structure more comprises:

One the 3rd protuberance, its curvature parameters are different from the curvature parameters of this first protuberance or this second protuberance.

9. rear projection screen as claimed in claim 7 is characterized in that, this first optical element is a lens pillar.

10. rear projection screen as claimed in claim 7 is characterized in that, this second optical element is a Fresnel lens.

11. rear projection screen as claimed in claim 7 is characterized in that, more comprises:

One light diffusion layer, it is arranged on another surface of the relative cylindrical projection structure of this optical element.

12. rear projection screen as claimed in claim 7 is characterized in that, is filled with light diffusion particulate in this first optical element.

13. rear projection screen as claimed in claim 7 is characterized in that, the sectional width of these light absorptive units is different each other.

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