Adaptive Projection Television Screen Mounting Clamps

Abstract

Strip mounts on the top and bottom screen mounting brackets for holding a projection display screen in place while accommodating screen tolerances are disclosed. The strip mounts have a C-shaped profile that holds the display screen in place. The screen mounting brackets are elongate, stiff members.

Description

FIELD OF THE INVENTION

The invention relates generally to a projection display and, in particular, details for mounting a projection display screen.

BACKGROUND OF THE INVENTION

Projection display televisions have become widely used. The cabinets for these projection display televisions are typically made from plastic. A problem that projection display televisions typically have is keeping the top edge of the screen straight and in the proper location. Plastic cabinets provide nice aesthetics but have a tendency to bow along the top edge, aggravating the ability to keep the top edge of the screen straight and in location. This is an even more severe problem on projection display televisions that incorporate upangle optics because such televisions require a more accurate screen location with respect to the optics.

Many projection televisions have a problem mounting the screen because of large dimensional tolerances and variations. A particular problem is the thickness tolerance of the screen. The screen is typically made up of multiple pieces that are laminated and/or taped together. Another problem is that the width and height of the screen may vary significantly as a function of temperature and humidity. The screen must be free to expand in width and height or it will bulge out. With the steep upangles involved in recent projection televisions, bulging of the screen can cause significant image distortions. Typically, these screens are held in a groove in metal wood or plastic. The groove has room for expansion and contraction of the screen and mating parts. The sloppy fit is acceptable for conventional projection television displays and on-axis microdisplay sets since the resulting image geometry is not distorted. However, with the steep upangles associated with recent projection display raypaths, changes in the location or position of the screen surface results in significant distortions to the image geometry.

SUMMARY

The present invention provides strip mounts to the top and bottom of the screen mounting brackets to hold a projection display screen in place while accommodating screen tolerances. The strip mounts have a C-shaped profile that holds the display screen in place. The screen mounting brackets are elongate, stiff members.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention will next be described with reference to the accompanying figures, of which:

FIG. 1A is a prospective front view of a projection display television according to an exemplary embodiment of the present invention;

FIG. 1B is a prospective rear view of the projection display television of FIG. 1A;

FIG. 2 is a partial rear perspective view of the projection display television of FIGS. 1A and 1B, showing the top extrusion according to an exemplary embodiment of the present invention;

FIG. 3A is an exploded side-view of the plastic screen frame, extrusions and strip mounts;

FIG. 3B is a sectional view of the plastic screen frame, extrusions and strip mounts of FIG. 3A; and

FIG. 3C is a sectional view of the extrusion and strip mount of FIG. 2.

DETAILED DESCRIPTION

The present invention, shown in FIGS. 1A-3C, provides an extruded metal hinge mechanism that keeps the top of the projection display television screen frame straight and allows the screen assembly to be removed from the front without the use of screws from the rear.

An exemplary projection display television is shown in FIGS. 3A-3C. The screen mounting bracket 50 has top and bottom aluminum extrusions, that are a continuous stiffener for the screen frame 12. Aluminum extrusions are inexpensive to fabricate and provide good dimensional stability and stiffness properties. Strip mounts 55A, 55B attached to the top and bottom screen mounting bracket 50 are used to hold a projection display screen 10 in place.

The screen mounting bracket 50A comprises: an anchoring portion 51 that attaches to the screen frame 12 and a “T” shape detail 56 to accept the strip mount 55. In an exemplary embodiment, the anchoring portion 51 conforms to projections and/or recesses in the screen frame 12 to form a press fit with the screen frame 12.

Strip mount 55A is attached to the “T” shape detail 56 of the screen mounting bracket 50A, while strip mount 55B is attached to the “T” details 56 of the screen mounting bracket 50B. In an exemplary embodiment, the strip mounts 55A, 55B have a C-shaped profile and may be made of a flexible plastic extrusion. When mated with the screen frame 12, there is space between the convex portion of the extrusion and the frame to accommodate the screen thickness. The profile of the strip mounts is such that C-shaped cross section allows the profile to flex and maintain a preload against the screen. The strip mounts 55A, 55B are continuous and evenly press against the screen 10.

The top and bottom screen mounting brackets 50A, 50B are metal extrusions that have a mating “T” shape detail 56 (FIG. 3C) to capture the strip mounts 55A, 55B. This mating detail 56 is such that the strip mounts 55A, 55B squeezes the metal extrusion. When there is pressure against the strip mounts 55A, 55B, the C-shape opens up allowing the height of the extrusion to collapse as needed to accommodate the screen thickness variation while maintaining a reasonable force. The plastic or elastomeric material used for strip mounts 55A and 55B is chosen to be chemically compatible with the screen 10 materials and to have surface hardness characteristics that prevent abrasion to the screen materials during shipping and vibration. Linear protrusions 58 incorporated in the strip mounts 55 act as “light strips” to reduce reflections of unwanted light onto the screen 10. A similar result could be obtained by having multiple small striations incorporated into the side wall of the strip mounts rather than the larger linear protrusions.

The screen mounting bracket 50A, 50B and the strip mounts 55A, 55B extend essentially the length of the elongate direction (i.e., entire width of the screen frame 12), stiffening the entire top edge of the screen frame 12, holding the top edge of the screen 10 straight and in the proper location.

The cabinet may be plastic, as is typical for projection display televisions. When mounted to a plastic cabinet, these brackets 50, in the form of extrusions, form a low profile, structural member along the top edge of the cabinet 20. This structural member can be tied into other structural members of the cabinet 20 to help maintain the critical location of the screen frame 12. Along with being very low cost to tool, aluminum extrusions tend to be inherently straight, stiff and stable as compared to other parts such as plastic extrusions, formed sheet metal, wood, or molded plastic.

The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. For example, while the exemplary embodiment shows aluminum extrusions for the structural members, the concept is also applicable with roll formed sheet metal or sheet metal parts made on progressive dies. It is intended, therefore, that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention be given by the appended claims together with their full range of equivalents.

Claims

1. A bracket for mounting a projection display screen to a cabinet from the front of the screen, comprising: a screen bracket attached to a screen frame having the screen mounted thereto; anda strip mount, wherein the strip mount is attached to the screen bracket and touches the screen.

2. The bracket of claim 1 wherein the screen bracket is continuous.

3. The bracket of claim 2 wherein the screen bracket has a constant cross section along the elongate dimension.

4. The bracket of claim 1 wherein the strip mount and the screen bracket are extrusions.

5. The bracket of claim 1 wherein the screen bracket is formed of aluminum.

6. The bracket of claim 1 wherein the strip mount is C-shaped.

7. A projection display, comprising: a cabinet;a screen mounted in a screen frame; andbracket for mounting the screen frame, wherein the bracket has a strip mount attached thereto and touching the screen.

8. The projection display of claim 7 wherein the bracket is continuous.

9. The projection display of claim 8 wherein the bracket has a constant cross section along the elongate dimension.

10. The projection display of claim 7 wherein the strip mount and the bracket are extrusions.

11. The projection display of claim 7 wherein the bracket is formed of aluminum.

12. The projection display of claim 7 wherein the strip mount is C-shaped.