Patent Publication Number: US-2011069238-A1

Title: Embedded recycle circuit for harnessing light energy

Description:
FIELD OF THE INVENTION 
     The present invention relates to liquid crystal display (LCD) devices used to display a picture on a television screen or computer monitor while harnessing unused light source energy. 
     BACKGROUND OF THE INVENTION 
     The active liquid crystal display (LCD) has been in use for over thirty-five years rather unchanged in function and structure. It is electronically-controlled optical device shaped into a flat panel and placed in front of a light source or reflector. The panel itself comprises an array of monochrome pixels, each of which consists of a layer of liquid crystals sandwiched between to transparent electrodes and two polarizing filters, whose axes of transmission are perpendicularly aligned. 
     In a black and white LCD, incident light passes through the first polarizer and contacts the liquid crystal, which refracts the light, thereby allowing it to pass through the second polarizer. The angle of refraction determines the amount of light passing through the second polarizer. Molecular structure of the liquid crystal, and the angle of refraction, is determined by the current applied by the transparent electrodes. 
     Color LCD&#39;s differ in that each pixel in divided into three subpixels that are colored by additional filters: red, blue, and green. Subpixels are controlled independently, yielding a vast number of possible colors. The liquid crystal structure itself, like the black and white LCD, is controlled by means of the transparent electrodes. The same refraction principles also apply. 
     The average amount of energy consumed by a modern LCD is less than that of a modern plasma television and slightly more than that consumed by CRT technology or DLP/rear projection televisions. Today, LCD TVs in the stand-by state (also the OFF state) consume anywhere from 0.1 W to 40 W, a variation due to updates being performed while the user is away from the TV. This can add up to a substantial amount of energy being consumed while the TV is not being used. Currently, a method of harnessing the light inside of the TV unused by the LCD panel does not exist. 
     SUMMARY OF THE INVENTION 
     Accordingly, a display device includes a chassis, a display on the chassis, and a light source to illuminate the display. The display device may be a TV or computer. In the case of the TV, a tuner to receive external signals and a processor to convert the signal into an image are mounted on the chassis. A recycle circuit is implemented to harness unused illumination outputted by the light source and store the energy in a battery. A light converter, such as a solar panel, receives excess light from the light source. The battery can power a standby module necessary for updates to the display device and for processing a wireless command signal received from a remote control when a main power supply to the light source is deenergized. A DC/DC Buck/Boost circuit may be used to transfer energy from the light converter to the battery and standby system. By generating its own power, the display device can be disconnected from the electrical grid, thereby saving a significant amount of power for the consumer and the electric company. 
     In another aspect, a display apparatus includes a chassis holding a display including display elements and a light source in the chassis and positioned to provide illumination to the elements of the display. The illumination is necessary to cause the display to present demanded images. Some of the illumination is excess illumination that does not illuminate the elements of the display but nonetheless requires power to generate. A recycle circuit advantageously is positioned in the chassis to receive and recycle the excess illumination so that not all of the excess illumination is wasted. 
     In another aspect, a display device includes an electronic display requiring illumination to present a demanded image. A converter is separate from the display and requires illumination to generate electricity. At least one lamp provides illumination to the display to facilitate presentation of the demanded image thereon and also provides illumination to the converter to facilitate electricity production thereby. 
     In another aspect, a method includes using a non-solar light source to illuminate a visual display to enable the display to produce a demanded image thereon, and simultaneously with using the non-solar light source to illuminate a visual display, using the non-solar light source to charge at least one battery. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a TV, showing interior components schematically; 
         FIG. 2  is schematic side elevational diagram illustrating the relation between an LCD module and the harnessing of unused light energy; 
         FIG. 3  is a view of a computer with the exterior over-molding removed, showing interior components schematically; 
         FIG. 4  is a block diagram of an alternate embodiment; and 
         FIG. 5  is a block diagram of yet another alternate embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to  FIG. 1 , a TV  10  includes a TV chassis  12  housing an LCD display panel  14  and processor  16 . A TV tuner  18 , mounted inside the TV  12 , receives TV signals in a format presentable in the LCD display  14  under control of the processor  16 . The processor  16  typically accesses one or more computer-readable media  20  such as but not limited to disk-based or solid state storage. A main power supply  22  and a standby power supply  24  typically are provided in the chassis  12  for purposes to be shortly disclosed. 
     For the LCD display  14  to present a demanded image, a light source  26  mounted in the chassis  12  generates light that illuminates the interior elements of the LCD display  14 . The light source  26  may include, but is not limited to, a cold cathode fluorescent lamp (CCFL) that receives power from the main power supply  22 . As set forth further below, a converter member is mounted on the chassis  12  as part of a recycle circuit  28  and receives light from the light source  26 . The converter member, such as an amorphous silicon solar panel, translates the light energy into electrical energy that can be input into a standby power supply circuit  24  also inside the chassis. The standby power supply circuit  24  may include, but is not limited to, a DC/DC buck/boost circuit receiving electricity from the converter member and communicating with a standby power supply battery. 
     The converter member of recycle circuit  28  may include at least one solar cell. By housing the solar cell, or solar panel, inside the TV  10 , the high intensity light source may be harnessed directly. The chassis  12  substantially blocks sunlight from impinging of the solar cell. 
     The standby power supply circuit  24  is necessary to keep the TV  10  active for updates and to provide standby power to process a wireless command signal received from a TV remote control when a main power supply to the light source  26  is deenergized. TV updates may include software upgrades, TV guide updates, system monitoring, etc. The standby power supply circuit  24  may include a battery charged by the converter member of the recycle circuit  28 . 
     Now referring to  FIG. 2 , a diagram of the interior of a TV  10  is shown with the chassis  12  removed. The LCD display  14  is backlit by the light source  26  as shown. As mentioned above, the light source  26  can be established in some example non-limiting embodiments by a CCFL backlight module  32 . Closely juxtaposed with the light source  26  on the side of the light source that is opposite from the display  14  is a converter member which may be established by an amorphous silicon solar panel  34 , it being understood that the solar panel  34  can be part of the previously designated recycle circuit  28  shown in  FIG. 1 . Thus, the light source  26  illuminates not only LCD display elements  36 , here shown only in part to represent the parallel orientation between the light source and LCD display panel on the TV display  14 , but also the light source  26 . 
     Each of the components of the overall LCD module may be mounted separately on the chassis  12  in orientations similar to what is shown in  FIG. 2 . The light from the light source accordingly is transformed by the LCD display elements  36 , yielding a demanded image represented by arrows  37  while the solar panel  34  absorbs light energy transmitted by the light source  26  but not otherwise used to illuminate the display elements  36 . In some implementations the electrical energy generated by the solar panel  34  is sent to a DC/DC Buck/Boost circuit  38 , which is an intermediate member of the recycle circuit shown in  FIG. 1 . The Buck/Boost circuit  38  communicates with a battery  40 . The battery provides standby power to process a wireless command signal received from a remote control when a main power supply to the light source is deenergized. These elements  38 ,  24 , and  40  are mounted in the chassis  12  of the TV  10 , but not necessarily in the relative orientation shown. 
     Moving in reference to  FIG. 3 , any display device, here a computer  42 , with an electronic display, here computer display  46 , requiring illumination to present a demanded image is exemplified. A computer chassis  44  encloses a processor  48 , medium  50 , light source  52 , and recycle circuit  54  and supports the display  46 . 
     The light source  52  consists of at least one lamp providing illumination to the display  46  to facilitate presentation of the demanded image thereon and providing illumination to a converter, which is integrated into the recycle circuit  54 , to facilitate electricity production thereby. The light source  52  may be, but is not limited to, a CCFL. The converter member of the recycle circuit  54  may be, but is not limited to, an amorphous silicon solar panel. The computer chassis  44  substantially blocks sunlight from impinging on the converter member. 
     As was the case for the display shown in  FIG. 1 , the recycle circuit  54  in  FIG. 3  includes an electrical storage device, such as a battery charged by the converter. The battery provides standby power for various non-limiting purposes, e.g., to process a wireless command signal received from a remote control when a main power supply to the lamp is deenergized. A DC/DC buck/boost circuit may be an intermediate member of the recycle circuit  54 , receiving electricity from the converter and communicating with the battery. 
       FIGS. 4 and 5  show alternate embodiments in which energy from the converter  34  is sent to a DC/DC/boost converter circuit or DC/DC buck converter circuit, respectively. Specifically, in  FIG. 4  a DC/DC boost converter circuit  60  receives energy from the converter  34  and outputs a higher voltage than the input voltage to charge a standby power supply battery  62 . The battery  62  provides power to a standby power supply circuit  64  when the TV is not energized, with the battery also receiving power from the TV when the TV is plugged in. As shown at nodes  66 , the standby power supply system  64  can receive current directly from the boost circuit  60 .  FIG. 5  shows an essentially identical circuit as shown in  FIG. 4  except that the DC/DC boost circuit  60  is replaced with a DC/DC buck converter circuit  68 , which outputs a lower voltage from a higher voltage input.