Enclosure for projection television sets

#The present invention relates generally to projection television sets, and more particularly to a projection television set enclosure.

#Projection television (PTV) sets are a popular alternative to picture tube television sets, as they provide relatively large viewable screens that cannot be efficiently produced using conventional picture tubes. PTV sets typically include an enclosure housing an optical unit, a mirror, and electronic components for receiving and projecting an image onto a screen assembly mounted on the front of the enclosure. The optical unit typically includes three projection tubes having a cathode ray tube (CRT) optically coupled to a projection lens. The three projection tubes project a red, a green, and a blue image on to a screen of the PTV.

#The conventional enclosure is typically divided into two compartments, an upper and a lower compartment. The CRTs and the printed wiring boards (PWB) are typically mounted in the lower compartment, the mirror and screen are mounted in the upper compartment, and the projection lens tends to extend from the lower compartment to the upper compartment. The upper compartment is typically sealed tightly in order to protect the inside of the compartment from dust and other foreign materials. The lower compartment typically includes ventilation holes, positioned adjacent the top and bottom of the compartment, to exhaust heat radiating from the CRTs and the PWBs.

#FIG. 1 is a schematic view of a projection television set of the prior art.

#FIG. 2 is a side view of a projection television set of the prior art.

#FIG. 3 is a side view of another projection television set of the prior art.

#Although the present invention is applicable to enclosures or cabinets for a variety of display devices such as digital light projection televisions, liquid crystal displays, etc., the following discussion focuses on enclosures or cabinets for projection television (PTV) sets for exemplary purposes only.

#Referring to FIG. 1, the components of a PTV set 100 are schematically shown to include a mirror M and three projection tubes 10R, 10G, and 10B for receiving and projecting a red, a green, and a blue image onto a screen S assembly mounted on the front of an enclosure (not shown). Each projection tube 10R, 10G, and 10B includes a cathode ray tube (CRT) 12R, 12G, and 12B optically coupled to a projection lens 16R, 16G, and 16B. A spacer 14R, 14G, and 14B is coupled to and between the CRTs 12R, 12G, and 12B and lenses 16R, 16G, and 16B. The assembled projection tubes 1R, 10G, and 10B are mounted to an enclosure mounting bracket 18 to position them in their correct angular orientation within the enclosure.

#Turning to FIG. 2, the conventional enclosure 20 of a PTV 100 includes top 22, bottom 24, front 26, rear 28, and first 40 and second 42 side (see FIGS. 4 and 5) panels, and is typically divided by an internal wall 30 into two compartments, i.e., upper 34 and lower 32 compartments. The CRTs 12 and printed wiring boards (PWBs) 36 are typically mounted in the lower compartment 32, while the mirror M and screen S are mounted in the upper compartment 34. The projection lens 16 typically extends from the lower compartment 32 into the upper compartment 34 through the internal wall 30. The upper compartment 34 is typically tightly sealed from the lower compartment 32 to protect the inside of the upper compartment 34 from dust and other foreign materials. The lower compartment 32 typically includes one or more sets of ventilation holes to exhaust heat radiating from the CRTs 12 and the PWBs 36. As shown, the lower compartment 32 includes a first set of holes 23 positioned adjacent the top of the lower compartment 32 and a second set of holes 21 positioned adjacent the bottom of the lower compartment 32.