OPTICAL ASSEMBLY FOR TELEVISION FRONT SCREEN

Abstract: An optical assembly device (10) for use in front of a television screen having a diagonal dimension of S, which optical assembly comprises four panels (12 to 15) connected together to form a hollow body (11) having a substantially rectangular open front side (16) of width W and height H and a substantially rectangular open rear side (17) of width W' and height H', the separation between the front and rear open sides (16 and 17) being D and the inner sides of the panels being reflective. The optical assembly (10) further comprises front and rear lenses (18 and 19) provided extending across the open front and rear sides (16 and 17), respectively, of the body (11), the front side of the rear lens (19) being reflective, wherein the dimensions are related according to the following formulae: 1) W = [1 + (W'/H' - beta )] . W'; 2) H = [1 + (W'/H' - beta )] . H'; 3) D = K . S; where: (i) beta = ( <SIGN> 5 - 1)/2; (ii) 0.1 < K < 0.2.

Description: OPTICAL ASSEMBLY FOR TELEVISION FRONT SCREEN ■ f The present invention relates to a television image i processing device for use in front of a television screen to enhance the enjoyment of television watching. δ According to the invention, there is provided a television image processing device for use in front of a television screen having a diagonal dimension of S, which imaging processing device comprises four panels connected together to form a hollow body having a substantially rectangular 10 open front side of width W and height H and a substantially rectangular open rear side of width W and height H' , the separation between the front and rear open sides being D and the inner sides of the panels being reflective, which image processing device further comprises front and rear 15 lenses provided extending across the open front and rear sides, respectively, of the body, the front side of the rear lens being reflective, wherein the dimensions are related according to the following formulae: (1) = [1 + (W'/H' - β)] • W 20 (2) H = [1 + ( */H' - β)] • H' (3) D = K • S Where : (i) β = (v^ - l)/2 (ii) 0.1 < K < 0.2 It is preferred that the front lens is a Fresnel lens. Preferably, the front lens is curved. In a preferred embodiment, the rear lens is planar. In a specific construction, the dimensions of the rear side of the body are substantially equal to that of a said television screen. The invention also provides a television set which incorporates such a television image processing device. The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a front perspective view of an embodiment of a television image processing device in accordance with the invention; Figure 2 is a sectional side view of the image processing device of Figure 1; and Figure 3 is a sectional plan view of the image processing device of Figure 2, Referring to the drawings, there is shown a television image processing device 10 embodying the invention. The image processing device 10 comprises a hollow body 11 which if is formed by four panels connected together, namely top panel 12, bottom panel 13 and two side panels 14 and 15, 5 each having the shape of a symmetrical trapezium. The body 11 has a rectangular open front side 16 and a relatively smaller rectangular open rear side 17. Extending across the open front end 16 of the body 11, there is provided a front lens 18 which is curved, being 10 convex on the front side and concave on the rear side. The front lens 18 is preferably a Fresnel lens. A Fresnel lens is a generally known form of lens which has a surface comprising a plurality of smaller lenses or is constructed with stepped setbacks, usually but not necessarily 15 circular. The open rear side 17 of the body 11 is occupied by a rear lens 19, extending there-across . The rear lens 19 is planar and has a reflective front side, but may be a curved lens. The image processing device 10 is to be used in front of 20 the screen of a television set (not shown). The television screen is generally rectangular and has a diagonal (corner- to-corner) dimension of S. The front side 16 of the body 11 of the image processing device 10 has a width of W and a height of H, whereas the rear side 17 has a width of W' 25 and a height H' . The separation between the front and rear sides 16 and 17 of the body 11 has a measurement of D, that being the depth of the body 11. The various dimensions or measurements are related according to the following formulae: (1) W = tl + (W , /H' - β)] - W (2) H = [1 + (W'/H' - β)] • H' (3) D = K • S In the formulae, β denotes the golden coefficient having a value of ( f * - l)/2 or about 0.618, and K denotes a constant having a value in the range between 0.1 and 0.2. In this particular embodiment, the width W and height H' of the rear side 17 of the body 11 of the image processing device 10 are chosen to be the same as the corresponding measurements of the television screen. As a result, the remaining dimensions of the body 11, namely the values of W, H and D, can be determined according to the above three formulae. It is, however, to be understood that the size of the body rear side 17 is not necessarily the same as that of the television screen, although the corresponding measurements are preferably in direct proportion. Taking as an example, the television screen has a width of 512mm (being the value of W ) and a height of 385mm (being the value of H' ) , and hence a diagonal measurement S of about 641mm. The value of the constant K is chosen to be 0.152. According to the formulae, the width W and height H of the front side 16 of the body 11 of the image processing device 10 are calculated to be about 876mm and 659mm, respectively, and the depth D of the body 11 is. about 97mm. Depending on the size of the television screen and the television watching distance, it is preferred that the focal length of the front lens 18 falls within the range of 200mm to 400mm and is more preferably 250mm. Likewise, the depth D of the image processing device body 11 is preferably in the range of 50mm to 150mm. In use, the image processing device 10 is positioned in front of the television screen, with the rear side 17 of the body 11 placed against or close to and aligned with the television screen. The use of the image processing device 10 will impart a certain degree of 3-dimensional quality to the television image passing through the device 10, as hereinbelow explained. The television image travels through the image processing device 10 in the following three different paths: 1. The first path being from the television screen directly through the rear lens 19 and the front lens 18 to the viewer; 2. The second path being from the television screen through the rear lens 19 to the panels 12 to 15 and then reflected by the panels 12 to 15 to and through the front lens 18 to the viewer; and 3. The third path being from the television screen through the rear lens 19 to the panels 12 to 15, then reflected by the panels 12 to 15 back onto the front side of the rear lens 19 and finally reflected by the rear lens front side to and through the front lens 18 to the viewer. By reason of the difference in travelling paths, the television image is subject to different actions of reflection, refraction and/or diffraction inside and through the body 11 of the described image processing device 10. The final television image is thereby made up of three components having different relative phase shifts and different angles of propagation. These television image components interact by way of optical interference and fall into slightly different vision areas, thereby producing a realistic 3-dimensional effect. It is to be appreciated that the television image processing device of the invention will also absorb or filter away some of the undesirable or harmful radiations, such as X-rays, from the television image. In the described embodiment, the image processing device 10 will also provide an enlarged television image. It is envisaged that the television image processing device of the invention may be provided as a separate (add-on) device or as an integral part of a television set. The invention has been given by way of example only, and various modifications of and/or alterations to the described embodiment may be made by persons skilled in the art without departing from the scope of the invention as specified in the appended claims.

Claims: CLAIMS 1. A television image processing device for use in front of a television screen having a diagonal dimension of S,. which imaging processing device comprises four panels connected together to form a hollow body having a substantially rectangular open front side of width W and height H and a substantially rectangular open rear side of width W and height H' , the separation between the front and rear open sides being D and the inner sides of the panels being reflective, which image processing device further comprises front and rear lenses provided extending across the open front and rear sides, respectively, of the body, the front side of the rear lens being reflective, wherein the dimensions are related according to the following formulae: (1) W = [1 + ( '/H* - β)] • W (2) H = [1 + ( '/H' - β)] • H' (3) D = K • S Where : (i) β = ({T - l)/2 (ii) 0.1 < K < 0.2 2. A television image processing device as claimed in claim 1, wherein the front lens is a Fresnel lens. 3. A television image processing device as claimed in claim 1 or claim 2, wherein the front lens is curved. 4. A television image processing device as claimed in any one of claim 1 to claim 3, wherein the rear lens is planar. 5. A television image processing device as claimed in any one of the preceding claims, wherein the dimensions of the rear side of the body are substantially equal to that of a said television screen. 6. A television image processing device for use in front of a television screen, substantially as hereinbefore described with reference to the accompanying drawings. 7. A television set incorporating a television image processing device as claimed in any one of the preceding claims.

Inventors: HE KAI SHENG, HE, KAI, SHENG
Applicants: LO CHUNG KIN, LO, CHUNG, KIN
Application year: 1992
Main classification: H04N5
IPC codes: H01J29, H04N5