GB2138160A

GB2138160A - Rear projection display apparatus

Info

Publication number: GB2138160A
Application number: GB08306743A
Authority: GB
Inventors: Michael William Parsons; Roland Wagner
Original assignee: JMC COMPAK Ltd
Current assignee: JMC COMPAK Ltd
Priority date: 1983-03-11
Filing date: 1983-03-11
Publication date: 1984-10-17
Also published as: GB8306743D0

Abstract

The invention provides rear projection display apparatus comprising a cabinet (1) having a lower part (2) for housing a projector (4) and an upper part (3) having a front wall comprising a screen (5). A mirror (6) is so mounted within the cabinet (1) that it can be moved from an in-use position in which it is contained in the upper part (3) of the cabinet (1) for reflecting images from the projector (4) onto the back of the screen (5) and an out-of-use position in which it is housed within the lower part (2) of the cabinet (1). The upper part (3) of the cabinet (1) is collapsable when the mirror (6) is in its out-of-use position so that the apparatus is more readily transportable and will readily pass through a standard door opening. The projection beam may be reflected from a fixed mirror (10) to mirror (6). <IMAGE>

Description

SPECIFICATION Rear projection display apparatus This invention relates to rear projection display apparatus.

Large size rear projection display apparatus having a rectangular screen which can measure, across its diagonals, as much as 1905 mm (75 inches) or more is known for displaying images to fairly large audiences, e.g., at conferences, lectures and the like.

Because of the large size of the screen and the size of the cabinet which is necessary to house the projector and mirrors for projecting images onto the rear of the screen, such large size rear projection display apparatus invariably has to be assembled in situ and cannot be transported from one location to another without being completely disassembled and reassembled in the new location.

The present invention has as its object to provide rear projection display apparatus, and particularly large size rear projection display apparatus, which is capable of having a large screen but which is readily transportable from one location to another without the need for disassembly and reassembly.

The present invention provides rear projection display apparatus comprising a cabinet having a lower part for housing a projector and an upper part having a front wall comprising a screen and a mirror mounted in said cabinet and moveable between an in-use position in which it is located in the upper part of said cabinet for reflecting images from said projector onto the back of said screen and an out-of-use position in which it is housed in the lower part of the cabinet, the upper part of the cabinet being collapsible onto the lower part of the cabinet when said mirror is in its out-of-use position to facilitate transport of the apparatus.

The lower part of the cabinet may have a front wall, a rear wall, opposed side walls and a bottom wall and may be open at the top whilst the upper part of the cabinet may have a front wall conprising said screen, a rear wall, opposed side walls and a top wall or cover and may be open at the bottom.The front wall of the upper part of the cabinet is preferably hingedly connected to the front wall of the lower part of the cabinet whilst the side walls of the upper part of the cabinet are preferably hingedly connected to the side margins of the front wall of the upper part of the cabinet so that the side walls of the upper part of the cabinet can be hinged inwards to lie against the rear surface of the front wall of the upper part of the cabinet and the front wall and side walls of the upper part of the cabinet then hinged down to lie flat, or substantially so, over the top of the lower part of the cabinet.The top wall or cover and the rear wall of the upper part of the cabinet may be formed separately with the rear wall hingedly connected to the cover or top wall so that it can be hinged to lie flat against the underside thereof and the cover or top wall then positioned over the top of the lower part of the cabinet so as to close the lower part of the cabinet and protect screen. When the upper part of the cabinet is collapsed in this way then the maximum dimensions of the cabinet are preferably such that the cabinet will readily pass through a standard doorway.

The said mirror may be supported by links which are pivotally connected thereto and to a bracket mounted within the cabinet, e.g., on the rear wall of the lower part of the cabinet, so that the mirror is moveable between said in-use and out-of-use positions. Preferably the mirror is a lightweight mirror formed from a metallised flexible sheet material, e.g., metallised Melinex (Registered Trade Mark) or other suitable plastics sheet material, although the mirror could if desired be a conventional silvered glass or other kind of mirror.

Prefereably the cabinet is formed from lightweight materials such as a laminate comprising a cellular or honeycomb core of paper of the like sandwiched between sheets of plastics, aluminium or other suitable material. The said screen may be formed from a suitable transluscent material, , 6mm thick acetate or other plastics material or a flexible sheet material stretched over a frame.

Said projector is preferably a video projector, e.g., a single gun monochrome video projector or a three gun colour video projector such as that sold under the Trade Mark Barcovision, although other forms of projector, e.g., a cine projector could be used if desired. The said projector may include an audio output or audio means may also be incorporated with the lower part of the cabinet. Likewise, a loud speaker or loud speakers for any audio output can also be incorporated in the cabinet. Preferably the arrangement is such that the images projected by said projector are reflected by a mirror mounted in the lower part of said cabinet onto said moveable mirror when the moveable mirror is in its in-use position and then onto the rear surface of said screen for viewing from in front of said screen.If desired or necessary said mirrors may be adjustable for angle to enable the images from said projector to be properly displayed on said screen.

The invention will be more particualrly described with reference to the accompanying drawings, in which Figure 1 is a front view of a rear projection display apparatus according to the present invention, Figure 2 is a side view of the apparatus of Figure 1 and Figure 3 is a side view of the apparatus of Figures 1 and 2 when in its collapsed condition.

Referring to the drawings it will be seen that the rear projection display apparatus illustrated comprises a cabinet 1 having a lower part 2 for housing a projector 4 and an upper part 3 having a front wall comprising a screen 5. Mounted within the cabinet 1 is a mirror 6 which is pivotally connected by links 7 to a bracket 8 mounted on a rear wall 9 of the lower part of the cabinet so as to be moveable between the in-use position shown in Figure 2 in which it is adapted to reflect images from the projector 4 onto the screen 5, and the out-of-use position shown in Figure 3. In addition to the mirror 6, a further mirror 10 is mounted on a triangular frame 11 is provided in the lower part of the cabinet for directing images from the projector 4 onto the mirror 6. The mirrors 6 and 10 may, if desired, be angularly adjustable.

The lower part 2 of the cabinet 1 comprises the said rear wall 9, a front wall 12, a bottom wall 14 and an open top. The upper part of the cabinet comprises a front wall 5a comprising the screen 5 which is hingedly connected to the front wall 12 of the lower part 2, opposed side walls 16 which are hingedly connected to the side margins of the front wall 5a so that they can be hinged to lie against the rear surface of the front wall 5a, a removable lid or cover 17 and a rear wall 18 which is hingedly connected to the lid or cover 17 so that it can be hinged to lie against the underside of the lid or cover 17. The front wall 5a, with the side walls 16 hinged to lie flat against the rear surface thereof, is adapted to fold flat over the top of the lower part 2 of the cabinet when the mirror 6 is in its out-of-use position.The lid or cover 17, with the rear wall 18 folded against the underside thereof, is adapted to fit over the top of the lower part 2 of the cabinet to close the cabinet and protect the screen 5 when in its collapsed condition as shown in Figure 3.

The mirror 6 is preferably a lightweight mirror comprising metallised plastics sheet meterial, e.g., such as that sold underthe Registered Trade Mark Melinex, stretched over a frame, whilst the screen 5 is preferably formed from a transluscent plastics sheet material such as an acetate plastics sheet material having a thickness of about 6mm. The cabinet is preferably formed from a plastics surfaced laminate comprising a core of honeycomb paper or like material surfaced on either side with plastics or other suitable sheet material.

The screen 5, when measured diagonally from corner to corner, may measure at least 914mm (36 inches), and preferably measures from 1524mm (60 inches) to 1905mm (75 inches), whilst the said cabinet, when in its collapsed condition, is preferably of a size such that it can easily pass through a standard doorway, erg., is preferably not more than 1425mm deep by 1625mm wide and 735mm high.

It will readily be appreciated that the rear projection display apparatus illustrated, when erected, has all the advantages of conventional large screen rear projection display apparatus whilst at the same time being quickly and easily collapsible to a size and form convenient for transport to another location.

Claims

1. Rear projection display apparatus comprising a cabinet having a lower part for housing a projector and an upper part having a front wall comprising a screen and a mirror mounted in said cabinet and movable between an in-use position in which it is located in the upper part of said cabinet for reflecting images from said projector onto the back of said screen and an out-of-use position in which it is housed in the lower part of the cabinet, the upper part of the cabinet being collapsible onto the lower part of the cabinet when said mirror is in its out-of-use position to facilitate transport of the apparatus.

2. Apparatus according to Claim 1, wherein the lower part of the cabinet has a front wall, a rear wall, opposed side walls and a bottom wall and is open at the top and the upper part of the cabinet has a front wall comprising said screen, a rear wall, opposed side walls and a top wall or cover and is open at the bottom.

3. Apparatus according to Claim 2, wherein the front wall of the upper part of the cabinet is hingedly connected to the front wall of the lower part of the cabinet and the side walls of the upper part of the cabinet are hingedly connected to the side margins of the front wall of the upper part of the cabinet, so that the side walls of the upper part of the cabinet can be hinged inwards to lie againstthe rear surface of the front wall of the upper part of the cabinet and the front wall and side walls of the upper part of the cabinet then hinged down to lie flat, or substantially so, over the top of the lower part of the cabinet.

4. Apparatus according to Claim 2 or 3, wherein the top wall or cover and the rear wall of the upper part of the cabinet are separate from the front and side walls of the upper part of the cabinet with the rear wall hingedly connected to the cover or top wall so that it can be hinged to lie flat against the underside of the cover or top wall then positioned over the top of the lower part of the cabinet so as to close the lower part of the cabinet and protect said screen.

5. Apparatus according to any one of the preceding claims, wherein the maximum dimensions of the cabinet when the upper part thereof is collapsed are such that the cabinet will readily pass through a standard door opening.

6. Apparatus according to any one of claims 2 to 5, wherein said mirror is supported by links which are pivotally connected thereto and to a bracket mounted within the cabinet so that the mirror is movable between said in-use and out-of-use positions.

7. Apparatus according to Claim 6, wherein said bracket is mounted on the rear wall of the lower part of the cabinet.

8. Apparatus according to any one of the preceding claims, wherein the mirror is a lightweight mirror formed from a metallised flexible sheet material.

9. Apparatus according to any one of the preceding claims, wherein the cabinet is formed from lightweight materials.

10. Apparatus according to Claim 9, wherein the cabinet is formed from a laminate comprising a cellular or honeycomb core of paper sandwiched between sheets of plastics, alluminium or other suitable material.

11. Apparatus according to any one of the preceding claims wherein said screen is formed from transluscent material.

13. Apparatus according to Claim 12 wherein said screen is formed from an acetate plastics material or a flexible sheet stretched over a frame.

14. Apparatus according to any one of the preceding claims, wherein said projector is a video projector.

15. Apparatus according to Claim 14, wherein said video projector is a single gun monochrome video projector or a three gun colour video projector.

16. Apparatus according to claim 14 or 15, wherein said projector includes an audio output or wherein audio means is incorporated within the lower part of the cabinet.

17. Apparatus according to any one of claims 14 to 16, wherein at least one loud speaker for audio output is incorporated in the cabinet.

18. Apparatus according to any one of the preceding claims wherein a second mirror is mounted in the lower part of the cabinet for reflecting images projected by said projector onto said movable mirror when the movable mirror is in its in-use position and then onto the rear suraface of said screen for viewing from in front of the screen.

19. Apparatus according to Claim 18 wherein said mirrors are adjustable for angle.

20. Rear projection display apparatus substantially as herein described with reference to the accompanying drawings.