HK1055152B - Large sized rear projection screen - Google Patents

Description

Large size rear projection screen

Technical Field

The present invention relates to rear projection screens, and in particular to large size rear projection screens.

Background

A conventional rear projection screen includes a fresnel lens for collecting incident image light, and a lenticular lens array for receiving the image light collected by the fresnel lens and having an external light absorbing portion and an image light emitting portion formed on an emission side thereof. For a smaller-sized screen for a rear projection television set, since a forming mold is small, a lenticular lens array in the screen can be formed in an integrally molded manner, but for a large-sized rear projection screen, such as 150 inches or more, if the lenticular lens array therein is still formed in an integrally molded manner, the mold cost thereof is very high or economically infeasible, and therefore, the large-sized rear projection screen is generally formed by combining a plurality of small rear projection screens, such as a large-sized combined rear projection screen disclosed in JP hei 10-260478, which includes a plurality of unit screens in the lateral and longitudinal directions, a side portion of each unit screen is fixed to a light blocking member at the rear by a screw, which is not provided in a gap between the adjacent unit screens, but is disposed inside the side edge portion of each unit screen so that adjacent unit screens can be closely coupled with each other with almost no black stripe of light blocking occurring, but many image blocking black spots still occur at the positions of the mounting screws at the side edge portion of each unit screen, the geometric size of which is much larger than the pixel units constituting the image, thereby deteriorating the sense of unity and continuity of the image.

Disclosure of Invention

It is an object of the present invention to provide a large-sized rear projection screen which does not have any obstruction to an image transmitted from the rear, thereby providing a complete image without any defects.

The object of the invention is achieved by a large-size rear projection screen comprising:

fresnel lens for collecting incident image light:

a lenticular lens array for receiving the image light collected by the fresnel lens and having an external light absorbing portion and an image light diffusing portion formed on an emission side thereof;

the lenticular lens array is composed of a plurality of lenticular lens units which are separated from each other, i.e., are independent, and are kept parallel to each other, adjacent lenticular lens units are closely arranged between the adjacent lenticular lens units so that no light flux loss occurs between the adjacent lenticular lens units, a region from a contact portion of the two to an image light exit side interface between the adjacent lenticular lens units constitutes a reinforcing region in which a screen mechanical strength reinforcing member is provided, the reinforcing member being connected to the respective lenticular lens units on both sides, and an external light absorbing portion being formed on an image light exit side in the reinforcing region.

According to the large-sized rear projection screen of the above-mentioned construction, since the reinforcing regions are formed in the lenticular lens array as the outer side of the screen, the reinforcing members are provided in the regions, which improve the impact resistance of the entire screen to the outside, the bending resistance is increased, the rigidity is high, and the lenticular lenses are not deformed, and the reinforcing regions are provided in the regions where no light flux loss is generated, and the reinforcing regions do not shield any light transmitted from the rear surface, so that the image seen from the entire screen has a sense of unity, maintains the continuity, and there is no shadow portion or black spot caused by the fixing screws as in the above-mentioned prior art, and further there is no thick stripe-shaped shadow portion caused by the many vertical and horizontal frames in the large-sized composite screen composed of a plurality of screen units each having a frame as obtained in the present market, since all the reinforcing regions are located in the regions where no light flux loss is generated, and all the reinforced areas are formed with external light absorption parts, so that the external light absorption part of the whole screen, namely the occupied proportion of black matrix is greatly increased compared with that of the traditional rear projection screen.

In the above-described rear projection screen, each lenticular lens unit may be formed of a plurality of elementary lenticular lenses whose axial planes are kept parallel to each other and are formed integrally.

According to the large-sized rear projection screen as described above, since each lenticular lens unit has a plurality of elementary lenticular lenses integrally formed, the number of units is reduced, the assembling efficiency is improved, and the cost of the screen can be reduced without losing the optical characteristics of the screen.

In the rear projection screen described above, each lenticular lens unit may be formed of a single elementary lenticular lens.

According to the large-sized rear projection screen as described above, since each lenticular unit is formed of the single unit element lenticular lens, the reinforcing region can be formed between each unit element lenticular lens, and the reinforcing member is provided therein, so that the rigidity of the entire screen is high, and further, since the material of the light absorbing portion formed between each unit element lenticular lens is uniform, so that the light absorbing effect of the entire screen is uniform.

In the above rear projection screen, the plurality of lenticular lens units may be formed by combining two kinds of lenticular lens units, the first kind of lenticular lens unit being formed by a plurality of elementary lenticular lenses whose axial planes are kept parallel to each other and are formed integrally, and the second kind of lenticular lens unit being formed by a single elementary lenticular lens.

In the rear projection screen described above, the first type lenticular lens unit and the second type lenticular lens unit may be arranged in such a manner that: one or more second type lenticular lens units are formed between the two first type lenticular lens units.

In the rear projection screen described above, the first-type lenticular lens unit and the second-type lenticular lens unit may be arranged in such a manner that one or more first-type lenticular lens units are formed between the two second-type lenticular lens units.

In the rear projection screen, the cross section of the stiffener can be Y-shaped or T-shaped, wherein the two front wings are located on the image light emitting side, the screen has a frame, and two ends of the stiffener are connected to the frame.

In the rear projection screen, the reinforcing member may have a polygonal cross section, one corner portion of which protrudes toward the image light exit direction.

According to the large-sized rear projection screen, since the front portion of the reinforcing member protrudes toward the outside, the lenticular lens is prevented from coming into direct contact with an external object, and the lenticular lens is prevented from being worn and damaged.

In the rear projection screen described above, the reinforcement may be formed of a rigid material with a black oxide layer or a black coating layer absorbing external light on the outer side of the reinforcement, i.e., the image light exit side.

In the rear projection screen, the rigid material may be a metal, a carbon fiber, or a non-metallic material having a high rigidity, and the metal may be a light metal such as an aluminum alloy.

If the above-described reinforcing member is made of an aluminum alloy, the weight of the screen can be reduced and a sufficiently high mechanical strength can be ensured.

The reinforcing member may be connected to the respective lenticular lens units at both sides in a tongue-and-groove fitting manner.

According to the large-sized rear projection screen as described above, the contact area between the reinforcing member and the adjacent lenticular lens unit can be increased, a sufficiently high connection strength can be secured therebetween, and the surface area of the absorption portion of the external light can be increased.

The reinforcing member may be connected to the respective lenticular lens units on both sides by an adhesive.

The external light absorbing portion in the reinforcing region may be formed of a black reinforcing member itself that absorbs the external light.

According to the large-sized rear projection screen, since the reinforcing member itself is a black member capable of absorbing light, it can simultaneously play a role of increasing rigidity and absorbing external light, simplifying the manufacturing process, and unlike the conventional screen in which the external light absorbing portion is a black stripe adhered or a black coating applied, the external light absorbing portion is easily damaged by abrasion or external force to reduce the absorbing effect.

The external light absorption part in the reinforcing region may be formed of a filler that absorbs external light filled in the region.

The fresnel lens may be composed of two pieces of lenses having linear fresnel fringes arranged in a front-back overlapping manner, and the linear fresnel fringes in the two pieces of lenses may extend in directions perpendicular to each other.

According to the large-sized rear projection screen as described above, the processing of the large-sized fresnel lens can be easily performed, thereby reducing the manufacturing cost.

The side surfaces of the reinforcing regions adjacent to the lenticular lens units on both sides are also formed with external light absorbing portions.

According to the large-sized rear projection screen, since the side of the reinforcing region other than the front side, i.e., the light exit side, is provided with the external light absorbing portion, the diffused light entering the inside of the lenticular lens through the diffuse transmission portion of the lenticular lens can be absorbed to a large extent, so that the proportion of the black matrix of the entire screen is greatly increased.

The large-size rear projection screen of the invention can be applied to large-screen moving image advertisements of television studios, airports and stations, large-screen moving image advertisements of luxury streets, industrial control large-scale image display monitoring systems (power plants, steel mills, chemical plants and the like), military command monitoring systems, simulated operation systems, auditoriums, conference rooms, large screen codification in multifunctional halls, audio-visual education, entertainment venues, movie theaters and the like.

Drawings

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view of one embodiment of a large size rear projection screen of the present invention:

fig. 2 is a perspective view of the lenticular lens array in the screen shown in fig. 1:

fig. 3 is a side view of the lenticular lens array shown in fig. 2:

fig. 4 is a perspective view of the elementary lenticular lenses constituting the lenticular lens array in fig. 3:

fig. 5 is a side view of the cellular lenticular lens shown in fig. 4:

fig. 6 is a perspective view of a stiffener in the lenticular lens array shown in fig. 3:

FIG. 7 is a side view of the reinforcement member shown in FIG. 6:

FIG. 8 is a perspective view of another embodiment of a lenticular lens array that forms a large-size rear projection screen of the present invention:

fig. 9 is a perspective view of a lenticular lens unit constituting the lenticular lens array in fig. 8:

fig. 10 is a side view of the lenticular lens unit shown in fig. 9:

fig. 11 is a schematic view of the side surface of the reinforcing member in fig. 2 capable of absorbing external light.

Best mode for carrying out the invention

As shown in fig. 1, as an example of a large-sized rear projection screen of the present invention, the screen includes a fresnel lens 4 for collecting incident image light, and a fresnel lens 3 for collecting light from the fresnel lens 4, the two pieces of fresnel lenses 3 and 4 are superposed on each other with the extending directions of respective linear fresnel stripes 8, 9 thereof kept perpendicular to each other, and the screen further includes a lenticular lens array 2 for receiving the image light collected by the fresnel lens and formed with an external light absorbing portion and an image light diffusing and transmitting portion on the outgoing side thereof.

As shown in fig. 1 to 3, the above lenticular lens array 2 includes a plurality of lenticular lens units 5, each lenticular lens unit 5 is constituted by only one elemental lenticular lens, as shown in fig. 3 and 4, an image light diffusing transmission part 7 is formed on an image light outgoing side thereof, adjacent elemental lenticular lenses 5 are kept parallel to each other and in close proximity so as not to form a light flux loss therebetween for image incident light, and a reinforcing region for increasing screen mechanical strength such as bending strength, impact resistance strength, and the like is formed in a space of a side surface of the adjacent elemental lenticular lens 5 and does not form a shield against incident image light.

As shown in fig. 6 and 7, a rigid reinforcing member 6, such as a plate strip made of an aluminum alloy, is provided in each reinforcing region, each of the plate-shaped rigid reinforcing members 6 has a polygonal cross section including two inclined surfaces 6c, 6d at the front, i.e., the outer side, and two inclined side surfaces 6a, 6b at the rear thereof, and has a rear surface 6e, a plurality of recesses 10 are formed in the two inclined side surfaces 6a, 6b, and the front inclined surfaces 6c, 6d and the inclined side surfaces 6a, 6b are each formed with a black oxide layer so as to absorb external light. Due to the formation of the concave portions 10, for screens with smaller geometrical sizes of the elementary lenticular lenses, the inclined side surfaces 6a, 6b are rough, so that friction force can be increased and the bonding area can be enlarged, and for screens with larger geometrical sizes, due to the larger geometrical sizes of the elementary lenticular lenses, corresponding convex portions can be machined on the side surfaces of the adjacent elementary lenticular lenses, so that a joggle structure is formed during matching, and firm connection between the two is ensured. The recess 10 may be filled with a black adhesive. Due to the above structure, the reinforcing member 6 can absorb external light and increase the mechanical strength of the screen, while not blocking image light from the fresnel lens, thereby providing a sense of unity and continuity to the image displayed on the screen.

As another example of the large-sized rear projection screen of the present invention, as shown in fig. 8, 9, and 10, the lenticular lens array in the screen is formed of a plurality of lenticular lens units 1, adjacent lenticular lens units 1 are kept parallel to each other and in close proximity so that no light flux loss is formed therebetween, and a reinforcing region is formed therebetween, the reinforcing region being formed of the reinforcing members 6 shown in fig. 6 and 7, each reinforcing member 6 being connectable to the adjacent lenticular lens unit 1 by an adhesive. Each lenticular lens unit 1 is formed of a plurality of integrally formed elementary lenticular lenses 12, an image light diffusing transmission part 11 is formed at an outer side part of each elementary lenticular lens 12, and an external light absorbing part 13 is formed between the image light diffusing transmission parts 11 of adjacent elementary lenticular lenses 12. The lenticular array in this embodiment can replace the lenticular array in the screen shown in figures 1 and 2, together with the two overlying fresnel lenses 3, 4 behind, to form a rear projection screen.

As shown in fig. 11, a rigidity reinforcing member 6 is connected to both sides of the individual element lenticular lens 5 constituting the lenticular lens unit shown in fig. 2, a plurality of concave portions 10 are formed on both inclined side surfaces 6a, 6b of the rigidity reinforcing member 6, and black light absorbing layers are formed on both front inclined surfaces 6c, 6d and the inclined side surfaces 6a, 6 b. Thus, with respect to the outer side of the single element lenticular lens 5, a part of the external light is absorbed by the front slope 6c, and another part of the external light is absorbed by the respective inclined side surfaces 6a, 6b of the reinforcing members 6 on both sides after passing through the diffuse transmission portion in the front of the element lenticular lens 5.

Claims (16)

1. A rear projection screen, comprising:

a Fresnel lens for collecting incident image light;

a lenticular lens array for receiving the image light collected by the fresnel lens, and having an external light absorbing portion and an image light diffusing and transmitting portion formed on an emission side thereof:

the lenticular lens array is composed of a plurality of lenticular lens units which are separated from each other, i.e., are independent, and are kept parallel to each other, adjacent lenticular lens units are closely arranged between the adjacent lenticular lens units so that no light flux loss occurs between the adjacent lenticular lens units, a region from a contact portion of the two to an image light exit side interface between the adjacent lenticular lens units constitutes a reinforcing region in which a screen mechanical strength reinforcing member is provided, the reinforcing member being connected to the respective lenticular lens units on both sides, and the external light absorbing portion is formed on the image light exit side in the reinforcing region.

2. A screen according to claim 1, wherein each lenticular unit is formed of a plurality of elementary lenticular lenses whose axial planes are kept parallel to each other and are formed integrally.

3. A screen according to claim 1, wherein each lenticular unit is formed from a single elementary lenticular lens.

4. A screen according to claim 1, wherein said plurality of lenticular lens units are formed by combining two kinds of lenticular lens units, a first kind of lenticular lens unit being formed by a plurality of elementary lenticular lenses whose axial planes are kept parallel to each other and are formed integrally, and a second kind of lenticular lens unit being formed by a single elementary lenticular lens.

5. A screen according to claim 4, wherein said first lenticular element and said second lenticular element are arranged in such a way that: one or more second type lenticular lens units are formed between the two first type lenticular lens units.

6. A screen according to claim 4, wherein the first lenticular element and the second lenticular element are arranged in such a way that: one or more first type lenticular lens cells are formed between two second type lenticular lens cells.

7. A screen according to claim 1, wherein said reinforcing member has a Y-shaped or T-shaped cross section in which two front wing portions are located on the image light emitting side, and the screen has a frame to which both ends of the reinforcing member are connected.

8. A screen as defined in claim 1 wherein said stiffening member is polygonal in cross-section with one of its corners projecting in the direction of image light exit.

9. A screen according to claim 1, wherein said reinforcing member is formed of a rigid material with a black oxide layer or a black coating layer absorbing external light on the outer side of the reinforcing member, i.e., the image light outgoing side.

10. The screen of claim 9 wherein said rigid material is metal, carbon fiber or a non-metallic material having a relatively high stiffness.

11. A screen according to claim 1, wherein said reinforcing member is connected to the respective lenticular lens units on both sides by a tongue-and-groove engagement.

12. A screen according to claim 1, wherein said reinforcing member is connected to the respective lenticular elements on both sides by an adhesive.

13. A screen according to claim 1, wherein the external light absorbing portion in the reinforcing area is formed of a black reinforcing member itself which absorbs the external light.

14. A screen according to claim 1, wherein the external light absorption portion in the reinforcement area is formed of a filler which absorbs external light filled in the area.

15. A screen according to claim 1, wherein said fresnel lens is composed of two pieces of lenses having linear fresnel patterns arranged in a front-to-back overlapping manner, and the linear fresnel patterns of the two pieces of lenses are arranged in directions perpendicular to each other.

16. A screen according to claim 3, wherein the side surfaces of the reinforcing regions adjacent to the lenticular lens cells on both sides are formed with external light absorbing portions.