MXPA97006481A - Double video display system - Google Patents

Abstract

A video display system having a cabinet and including a projector incorporating a liquid crystal display, digital light processing or other electronic video display technology and adapted to be used in said system in a subsequent projection mode or in a front projection mode when the projector is removed from the system

Description

DOUBLE-USE VIDEO DISPLAY SYSTEM BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention is directed to a video display system having a cabinet and including a projector incorporating a liquid crystal display, digital light processing (DLP ™) or other electronic video display technology and adapted for use in said system in a "back" projection mode or in a "front" projection mode, when the projector is removed from the system. 2. DESCRIPTION OF THE PREVIOUS TECHNIQUE Currently, back-view video viewer systems are available, typically including a large cabinet containing mirrors and a video projector inside the cabinet. These cabinets are very cumbersome, heavy, have a great depth and the optics in them must be carefully aligned, particularly if they emanate three images of three CRTs in the cabinet. In addition, if the projector and the mirrors inside the cabinet move in relation to the screen, the image becomes poor, since the proper convergence is destroyed. This usually results in color distortion.

In addition, such rear-screen video display systems typically are neither portable nor "modular" in construction, and the various components of the system can not be separated or folded to become portable, to facilitate component replacement and / or packing convenience. . Projection video display systems, which do not require a screen and project an image directly onto a wall, are described in the E patents. U .A. , Projectavision, Nos. 5,012,274 and 5,300,942. However, for example, when there is inadequate wall space or if the wall is painted a dark color, or the wall has uneven surfaces, or is in a room with too much light, the images of said television video display systems of projection can not be easily and clearly seen, in addition, there is usually no place for convenient placement of the projector, and people can inadvertently walk towards the path of the beam. A back screen video display system with a portable, foldable rear screen video display cabinet is also described in the U.A.A patent. , Projectavision, No. 5,491, 585. Rear screen projection televisions, CRT, are also available, but these are very heavy and bulky and take up too much space in a typical room. In addition, movers are required for the installation of said units and the subsequent movement of such units is very difficult. In addition, certain images of the projection video display of certain rear view video display systems have a poor quality. Accordingly, an object of the present invention is a video display system with a projector, which is easily and quickly removable from a cabinet and which can be used in the "interior" or "in" of the system in a "posterior" projection and out of the system in a "frontal" projection mode. Another object of the invention is a video display system, wherein the projector can be easily inserted and properly positioned within the system in a fixed position. A further object of the invention is to provide a video display system, which can be folded (folded), is easily portable, and which can be sent within, for example, the normal tolerances of U PS® and Federal Express® . Furthermore, an object of the invention is a rear screen video display system, which has a less bulky appearance. A further object of the invention is a video display system, in which the components of the whole system have a "modular" construction in order to be portable, to easily replace the main components and for packaging convenience. A further object of the invention is a video display system having a security accessory, which terminates the flow of energy to the adjoining surface between the projector and the system under the removal of the projector. Yet another object of the invention is a video display system, which is easily assembled once it is removed from its shipping packages.

COMPENDIUM OF THE INVENTION These and other objects of the invention, which will be apparent below, are achieved by providing a video display system that includes a cabinet having a base unit, a display unit, a pedestal having a projector housing or a station. "Deposit" to receive the projector, and which has mechanical and / or electronic connections and means to easily insert and place the projector exactly in the storage station. In one embodiment, the display unit can be removed from the central pedestal, which, in turn, can be removed from the base unit. The display unit in one embodiment is deployed from a thin profile to an operational frame configuration A. In a preferred embodiment, the video display system incorporates digital light processing technology characterizing semiconductor light switches of digital micromirror device (DMD). ™) in a light beam valve to better direct the image of each pixel. The invention will be better understood from the following detailed description of the preferred embodiment, when read with reference to the accompanying drawings, in which: Figure 1 is a front perspective view of the video display system according to the present invention; Figure 2 is a perspective, front, exploded view of the video display system of Figure 1; Figure 3 is an angled, front perspective view of the display unit of the video display system; Figure 4 is a top cross-sectional view of the display unit of the video display system; Figure 5 is a side view of the display unit showing the pivot points, which facilitate folding and unfolding of the display unit to an operational position; Figure 6 is a side view of the video display system showing a deposit station on the pedestal, to keep the projector in an operational position; Figure 7 is also a side view of the video display system showing the depot station, but with the projector housing in an open position for removal and insertion of the projector; Figure 8 is a schematic side view of the base and pedestal of the system showing the relative position of the project and adapter board attached and exposed on the back of the pedestal, to use the projector in a subsequent projection mode; Figure 9 is a cross-sectional, side view of the projector showing the relative position of the adapter board when the projector is going to be used in the front projection mode; Figure 10 is a perspective view, partially cut away of the projector housing of the storage station of the video display system, showing a connector, a connector assembly and positioning slots; Figure 11 is a perspective view of another embodiment of the connector in the box; Figure 12 is a perspective view of one more embodiment of the connector in the box; Figure 13 is a rear perspective view of the projector showing the adapter board; Figure 14 is a front view of the box to hold the projector, showing the projector connector and the positioning slots; Figure 15 is a schematic view of the "self-aligning" connector assembly, in the form of a truncated, condescending pyramid; Figure 16 is a schematic view of the location scheme of the projector, showing the positioning slots and locating pins; Figure 17 is a front perspective view of the projector showing a bidirectional signal receiving capability of the I R receiver over the projector; and Figures 18A and 18B are views in front and side cross section.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Referring to the drawings, where similar numbers reflect similar elements through the various views, Figure 1 is a front perspective view of the dual-use video display system according to the present invention. The main structural components of the cabinet are generally injection molded of a glass-filled material, Noryl®, and include a display unit 100, a pedestal 400 and a base unit 500. The display unit 100 has a top mirror panel 200 (see Figure 2) and a lower mirror panel 300, a mirror 120 (see Figure 5), a screen holder 185 and a screen 180. The pedestal 400 supports the display unit 100 and has a "storage station". "700 (Figure 7), to keep a 710 projector in an operational condition within the system. A projector control access slot 705, in front of the pedesta l 400, allows a user of the system to access the projector controls without having to remove the projector 710 from the storage station.

The display unit 100 opens in a frame "A" shape, as if it had a foldable backrest (Figure 5), which is bent inwardly and extends outward, aided by two pivot points, 190, 195. The folding capability of the frame A allows the display unit 100 to have a shallow profile to reduce the volume of shipping purposes. The "A" frame also prevents the user from having access to the front of the mirror surface and to the back of the viewing screen 180, when the display unit 100 is folded. The display unit 100 may also include consumer-removable image frames, 220, which circumscribe the display 210. These frames 220 may be interchangeable to suit decorative tastes or, for example, if they wear out. The viewing screen (see Figure 4) is secured, by means of horizontal and vertical screen bevels 130, injection molded, to the screen support 185 and comprises several layers. In one embodiment, the screen 180 comprises three layers, mainly a) a Fresnel 160 sheet (approximately 99.06 cm x 127 cm, and with a thickness of approximately 0.4064 cm), which directs the wide-angle light and aligns it through of the screen, b) lenticular lenses 165, and c) black strips 175 to reject ambient light. There may optionally be a cover of a thin sheet of optical quality plastic to avoid fingerprints or smudges. In another embodiment, the screen has two layers, a Fresnel layer 160 and a diffusive layer 155, which scatters the light.

The preferred optical characteristics are as follows: The mirror 120 is sandwiched between the front edges 210 of the mirror panel 200 and the trailing edge 190 of the display unit 100 is a mirror 120 (see Figure 7). The mirror is trapezoidal and is composed of a thin, transparent plastic film, coated with a reflective surface layer and tensioned on a rigid foam support structure. The following table describes the preferred optical, mechanical and environmental requirements of the mirror: The base unit has a base plate 505 (see Figure 2), which, together with the pedestal 400, must be of sufficient weight and configuration to prevent displacement of the entire system when a 710 projector is inserted or removed from the base. box 720 of the projector, which houses it (see Figures 6 and 7). The base plate 505 contains four bolts (see Figure 1) for mounting the pedestal 400 and preferably weighs 6.81 kg and optionally has locking wheels and / or rollers 510 (see Figure 6), which allow the movement of the system with the projector inside. . The bottom of the base plate 505 also contains depressions for spring-loaded drag pads 520 (see Figure 7). The base plate covers 530 cover the base plate 505 and provide a better aesthetic appearance. Said covers 530 can also be easily changed if they wear out or simply to suit decorative tastes. Between base unit 500 and screen unit 100 is pedestal 400 (see Figures 6 and 7). The pedestal further includes a lower back support structure 430, injection molded, (see Figure 2) which weighs approximately 0.908 kg. In a preferred embodiment, the pedestal 400 has a width substantially less than the length of the screen 210. However, pedestal joints 410 (see Figure 2) can be attached to be placed in the space and give the overall system an appearance more than type of box" . 410 joints can be replaced by horns, shelves, etc. The pedestal allows a sufficient flow of air, so that the projector 710 does not overheat, that is, it should preferably dissipate around 250 watts of heat, which represents the heat of a potential combination / projector, VCR, and reproducer. of compact discs. A box molded by injection 720 (see Figure 7), which weighs approximately .454 kg, is also injection molded and weighs approximately 1,362 kg, is constructed on pedestal 400. Box 720 allows easy switching of the projector between the front and rear projection modes. The total time for the average consumer to assemble the entire system is preferably no more than 30 minutes. No special tool is required. All assembly and structural components are kept to a minimum. The complete system can preferably be contained within three containers. The lower base, the pedestal and the display unit are removable separately to facilitate shipping and assembly by the customer. The whole cabinet can be packed in a box with a length and perimeter <419.1 cm to meet the U guide lines. P. S. and Federal Express. Figure 7 is a side view of the system illustrating the box 720 in an open position. To insert (or remove) the projector 710, the user must open the case either through mechanical means, such as a handle (observe pivot point 740), or through motorized means, and slide the projector 710 towards its position, aided by certain self-alignment mechanisms, as described herein. In the rear projection operation mode, the projector 710 (see Figure 6) sits in a box 720 and projects an image towards the mirror 120, which reflects the image to the screen 210. In addition to the projector 710, it is also They can store in the box 720 front projection lenses, remote control, extra replacement bulbs, etc. An inwardly sloping tab on the upper edge of the box 720 and slightly tapered sides of the box 720 facilitate the initial total self-aligning of the projector 710 during insertion. The projector 1 10 and the box 720 are of a complementary shape, so that the projector 710 is fixed with a relatively small lateral movement (< +/- 0.635 cm). The projector 710 has a cavity 750 at its bottom end to allow insertion and partial containment of the adapter board 800, when the projector 710 is used in a front projection mode. The truncated pyramid connector 760 assembly places the connector 910 at a distance above the bottom of the box 720, so that it may coincide with the complementary connector in the projector cavity. (See Figure 19). The truncated pyramid shape of the connector assembly 760 ensures that the connector assembly 760 achieves full alignment with the projector 710, while the projector is inserted into the box for use in the rear projection mode. In a preferred embodiment, the final self-alignment of the connector is achieved by matching the two tapered pins 915 (see Figure 19) over the "sub D" connector in the condescending connector assembly with complementary holes on the matching connector in the projector cavity 750 Figures 8 and 9 illustrate the projector 710 and two adapter boards 800, 801, in the rear and front projection modes, respectively. In the rear projection mode, the adapter board resides in the pedestal unit 400 and is accessed from the rear of the pedestal. Energy and signal enter through the back of the unit. In the front projection mode, the power and signal go to the back of the projector via the adapter board 801. Figures 10-12 illustrate three embodiments of the projector connections in the box 720. In the embodiment of Figure 10, a single connector 910 is presented at the upper end of an assembly 920. Figure 1 1 illustrates two connection points . The connector point 930 has a plurality of connection points, v. gr. , for energy and signal, concentrated in a mechanical element. Figure 12 again illustrates an individual connector, which is "loose" to make a manual connection before placing the projector in the box. Once the projector 710 has been correctly inserted and the case closed, a releasably fitting accessory, best shown in Figures 14-16, ensures that the projector is placed exactly for operation. The box 720 has cuts 770, 780 (see Figure 14), which respectively receive positioning elements (balls) 800, 810 (see Figure 16), while the ball 820 is brought into direct contact with the projector 710 (see Figure 16). Upon closing the box 720, the ball 800 contacts the receptacle 800A and restricts the movement of the projector 710 along the X, Y, Z axes. The ball 810, when closing the box 720, is fixed on the slot 810A, and prevents movement of the projector 710 on the axes? xy? z, while the ball 820 bears against the flat region 820A, and prevents movement of the projector 710 and the box 720 in the direction? y. The three-ball location system provides the exact location of the 710 projector. In order to preserve this precise location, all other connections to the projector (eg, power + signal) must float mechanically. This is achieved in the preferred embodiment through the ease in connector assembly. In this embodiment, the facility is achieved by making the connector assembly 750 of an elastomeric material. The cavity 750 is contiguous with the end panel of the receptacle 800 A containing the projector and the slot 810A. (See Figure 18A). The slot and the receptacle, when resting on location balls 810 and 800, respectively, determine the vertical location of the projector 710 within the cabinet, and, therefore, determine the length of the optical path between the projector 710 and the screen 180. Due to slight manufacturing variations in the elements that make up the lens system, each projector will have a slightly different focal length. In order to eliminate the variation in the projected image size on the screen, so that, for example, all image sizes on all systems are 152.4 +/- 0.635 cm, the projector's motors must be located at different distances from the screen 180. In the preferred embodiment, differences in this distance are achieved by adjusting the location of the slot 810A and the receptacle 800A within the projector 710. The adjustment is made once during manufacture. Once the adjustment is complete, any 710 projector will provide an almost identical image size in any cabinet, allowing interchangeability for convenience in manufacturing, service and replacement. Adjustment of the location of the slot and the receptacle within the projector is achieved by placing the cavity 750 within the projector 710, using slots 795 and fasteners 796. Two pairs of interlocked serrated regions 790 and 790A (see Figure 18B) ensure that a Once the fasteners are tightened, there can be no relative movement between the cavity and the projector. The deposit station directs all the wiring / connections, so that they are not accessible to the user. No wiring within the storage station does not cause any loss of signal between the projector and subsequent connections. All manual controls such as DI ON / OFF, volume, and channel are preferably contained in the same projector 710 and are accessible to the user in the front of the cabinet. The pedestal 400 allows the repeated alignment of the projector 710 as well as ease of positioning, i.e., preferably not more than 2.27 kg of force. The alignment mechanism preferably withstands 5000 inserts / removals. Figure 13 shows the projector with the 800 adapter board incorporated in its back. The following connectors are accessible on the back of the cabinet via the adapter board: As a safety feature, the adapter board also contains a circuit system, so power is not passed to the sub D 899 connector (this is the connector that is in the condescending connector assembly, unless the projector As an additional safety feature, the adapter board comprises an open door interlock system, so that when the access door, on the projector housing (to replace a bulb, etc.) is open, the power is not passed to the sub D connector. Any wiring and / or physical enclosures are designed so that they do not act as antennas, that is, any emission will pass the emission requirements of FCC, CFR 47, part 15, subpart B , class A. Ventilation openings will be designed for the electronics, in such a way that they prevent the consumer from having an unnoticed access to UL Normal 1492. In one embodiment of the invention n, a remote control (not shown), can work directly with the same projector. This avoids the need to replicate a remote control signal receiver on the same main unit. The remote control operates together with a bidirectional I R receiver on the projector. (See Figure 17). The bidirectional nature of the I R receiver allows the remote control to be used within the projector in both front and rear projection modes. This pair of receivers are necessary due to the horizontal / orientation change from the front to the rear projector. The electronics contained within the projector are preferably composed of the Texas Instruments Light Engine (DMD), Video-Audio Processor, Power Supply, Keyboard, Adapter Board, and Controller Boards. It should be noted that, of course, liquid crystal displays (LCDs) or other electronic display projectors can alternatively be used. The light beam valve system is housed approximately in the following dimension: 30.4 cm A x 29.2 cm D x 16.5 cm A, and it will have an air inlet located at the bottom and coming out at the top. The above dimensions include sufficient space for a printed circuit board of 1 5.2 cm x 20.3 cm to be mounted. Connectors and electronics are provided, so that the entire system can be used as a computer SVGA monitor, in the projection mode either front or back. The projector includes a projector motor comprising a light and electronic beam valve system contained within an enclosure and a lens. Due to the focal length requirements for front and rear projection and substantially different, at least two lens systems can be provided. The two alternative systems are: • System 1: The lens system for the rear mode is contained in the cabinet and the lens for the front mode is contained in a front auxiliary chassis (not shown). The projector motor can be used either inside the cabinet or inside the front chassis. The front chassis contains the front lens system as well as the necessary elements for the projector to be interconnected with VCR, antenna, etc. • System 2: The user manually changes lens systems to allow operation in the desired front or rear mode. This will require the back cabinet to accept the projector with the rear lens attached. In the frontal projection mode, the user joins a front lens and an adapter board is used that contains all the appropriate elements for the interconnection with VCR, antenna, etc. The rear projection lens is used with the light beam valve system, while it is inside the cabinet and is capable of maintaining a contrast ratio of 200: 1 at a spatial frequency of 0.5 line pairs per mm, measured in the Spatial light beam modulator. The posterior projection lens successfully forms images of the modulated light through the digital mirror device at an appropriate distance with minimum performance specifications and does not contain more than .004 mm of lateral chromatic aberration in the spatial light beam modulator. The rear projection lens has a transmission greater than 80% across the entire visible spectrum, defined as 400 nm to 700 nm sling lengths. The total system has a general requirement to produce 300 lumens. Once the projector 710 is in the system, in order to use the projector 710 in the front projection mode, the following steps have to be taken: 1) open the 720 box; 2) pull projector 710; 3) exchange projection lenses; 4) insert the adapter board 801; and 5) connect the power and signal cord. Since preferred and alternative embodiments of the invention have been shown in detail, modifications and adaptations may be adapted thereto, without departing from the spirit and scope of the invention as outlined in the following claims.

Claims (9)

1 .- A video display system, comprising: a cabinet that includes a screen; a projector that is removably secured in the cabinet and adapted for the front and rear projection of an image; means for releasably locating said projector in the cabinet, in a fixed relation to said screen; means to consolidate the separable signal and power connections to the projector; and mirror means located in the cabinet to reflect an image of the projector onto the screen, when the projector is used in the rear projection mode. 2 - The video display system according to claim 1, wherein the cabinet comprises: means for holding the screen; and means for supporting said projector in the cabinet. 3. The video display system according to claim 2, wherein said support means and said support means are separable. 4. The video display system according to claim 1, wherein said releasable location means comprises at least three location elements. 5. The video display system according to claim 1, wherein said releasable location means comprises a ball in a receptacle. 6. The video display system according to claim 2, wherein said releasable location means comprises a ball in a slot. 7. The video display system according to claim 3, wherein said releasable location means comprises a ball against a plane. 8 - The video display system according to claim 1, further comprises self-aligning means for establishing said separable connections. 9. The video display system according to claim 1, wherein said releasable location means comprises a box. 10. The video display system according to claim 8, wherein said self-aligning means comprises a condescending connector assembly. 1 .- The video display system according to claim 10, wherein said condescending assembly is on a base surface of the box. 1

2. The video display system according to claim 10, wherein said condescending assembly is on the projector. 1

3. The video display system according to claim 2, further comprising means for actuating the projector controls, while said projector is placed on the support means. 1

4. The video display system according to claim 13, wherein said means for actuating the controls comprises an opening in the pedestal. 1

5. The video display system according to claim 1, further comprising a remote control that communicates with the projector. 1

6. The video display system according to claim 2, wherein said support means comprise means for folding the screen. 1

7. The video display system according to claim 2, wherein said means for supporting the projector is a substantially vertical support member having a width substantially smaller than the length of the screen. 1

8. The video display system according to claim 15, wherein said consolidation means comprises an adapter board. 1

9. The video display system according to claim 18, further comprising means for suspending power to the connection means, if said projector is not connected. 20. The video display system according to claim 18, wherein said adapter board comprises indicating means for the front / rear mode, so that the projector circuit system allows the appropriate I R receiving means a remote control. 21. The video display system according to claim 20, wherein the receiver for said remote control comprises a pair of receivers (substantially orthogonal), one adapted for the front projection mode and the other adapter for the subsequent projection mode. 22. The video display system according to claim 18, wherein said means for suspending the power comprises an open door indicator on said projector. 23. The video display system according to claim 4, further comprising means for adjusting the position of the optical system with respect to said location elements. 24. - The video display system according to claim 23, wherein said adjustment means comprise geometric interconnection accessories.