Abstract:
An apparatus comprising a monitor and a base. The base may be configured to display a plurality of characters received from both a first source within the monitor and a second source. The base may be connected to the monitor through a physical connection and an optical connection. The optical connection may transmit the characters received from the first source within the monitor. The optical connection may use a passive light source derived from a backlight source of the monitor.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to computer input devices generally and, more particularly, to a method and/or apparatus for implementing a laptop input device that may use wasted light from a display backlight. 
       BACKGROUND OF THE INVENTION 
       [0002]    Conventional laptop computers have a display and a keyboard. The keyboard is used to capture and transmit information from a number of keystrokes typed into the computer. The typed characters are shown on the display. In normal lighting conditions, distinguishing and correctly typing the various characters is not a problem. In low light conditions, it can be difficult to see the keyboard characters, often resulting in the incorrect typing and/or entering of one or more characters. Conventional low light solutions include (1) relying on the ambient light from the display to illuminate the keyboard, (2) turning on an external light source to provide additional illumination or (3) backlighting the keyboard with a light source located in the keyboard. Ambient display light is often not sufficient for very low light situations, or situations that the display is tilted back at an angle greater than 90 degrees. For the case of an external light source, a source may not be readily available or such use would be obstructive to individuals in the vicinity. For keyboards that do provide backlighting of the key characters, a separate light source is used. A separate light source reduces battery life for situations and adds additional manufacturing cost for the piece parts. 
         [0003]    Computers with touch screens are becoming more popular. Touch screens can be an alternate way to provide a user interface for entering data, often in addition to a conventional keyboard. 
         [0004]    It would be desirable to implement a computer keyboard that may provide a light channel between a display and a keyboard. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention concerns an apparatus comprising a monitor and a base. The monitor may be configured to display a plurality of characters received from both a first source within the monitor and a second source. The base may be connected to the monitor through a physical connection and an optical connection. The optical connection may transmit the characters received from the first source within the monitor. The optical connection may use a passive light source derived from a backlight source of the monitor. 
         [0006]    The objects, features and advantages of the present invention include providing a computer keyboard and/or monitor that may (i) use light received from a monitor backlight source as a keyboard backlight, (ii) provide an optical connection between a keyboard and a monitor, (iii) transmit data over the optical connection, (iv) provide a directional light source to be unobtrusive and/or (v) use scattered (or wasted) light to avoid a dedicated light source to reduce overall power consumption. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    These and other objects, features and advantages of the present invention will be apparent from the following detailed description and the appended claims and drawings in which: 
           [0008]      FIG. 1  is a diagram of an embodiment of the present invention; 
           [0009]      FIG. 2  is an alternate embodiment of the present invention; 
           [0010]      FIG. 3  is an alternate embodiment of the present invention; 
           [0011]      FIG. 4  is an alternate embodiment of the present invention; and 
           [0012]      FIG. 5  is an alternate embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0013]    The present invention may provide a lighting system that may be used to illuminate a keyboard. One example implementation may be a battery powered notebook computer or tablet computer. The illumination may help a user to easily distinguish the keys and/or characters in low and/or very low light conditions (e.g., near complete darkness). The light source may be directionally limited to the keyboard and/or not be obstructive to neighboring individuals. The light source may be implemented without a dedicated light source and/or associated additional costs and/or additional battery drainage. 
         [0014]    The lighting system may be built into the base of the laptop display. A light source may provide sufficient illumination to make the characters on a laptop (or notebook) keyboard easily distinguishable, even in very low light environments. In one example, the light system may be directional to illuminate mainly the keyboard, but not other surrounding components that do not need to be illuminated. 
         [0015]    Referring to  FIG. 1 , a diagram of a computer  100  is shown in accordance with an embodiment of the present invention. The computer  100  generally comprises a section  102  and a section  104 . The section  102  may be implemented as a base/keyboard section. In addition to a keyboard, the section  102  may include other components typically used in the base of a notebook computer (e.g., a central processing unit (CPU), other processing circuitry, etc.). The section  104  may be implemented as a monitor (or display). A hinge  106  may connect the base  102  to the monitor  104 . A block (or circuit)  108  may be implemented as a backlight section. In one example, the backlight section  108  may be implemented as an LED backlight to the display  104 . The LED backlight  108  may also transmit light to the display  104  in a direction marked by an arrow  110 . An arrow  112  marks light that may be used to illuminate the keyboard  102 . The light in the direction of the arrow  112  may be scattered (or wasted) light that does not get used by the display  104 . A block (or circuit)  114  may represent a waveguide. The waveguide  114  may be implemented as a rectangular or cylindrical pipe or tube. The waveguide  114  may be used to focus the scattered light in the direction of the arrow  112 . 
         [0016]    The waveguide  114  may be used to direct light from the back (or bottom) of the backlight LEDS  108  out the bottom of the display  104 . By using the same LED source for both the backlight of the display  104  and to illuminate the keyboard  102 , an energy savings may be implemented. In one example, a separate set of one or more LEDs (not shown) may be implemented to provide additional illumination. 
         [0017]    In one example, the computer  100  may use one or more backlight LEDS of the monitor  104 . Such backlight LEDs are normally situated along the lower long edge of the display (to be described in more detail in connection with  FIGS. 4 and 5 ). The backlight LEDs may be used to provide backlight for the display  104 . Since the backlight LEDs emit light from both the top and bottom (e.g., in a surface emitting device) and from the front and back side (e.g., in an edge emitting device) the light from either the bottom or back of these LEDs may be used to provide illumination for the keyboard  102 . The light from the backlight LEDs may be directed via the waveguide structure  114  onto the keyboard surface. In one example, a dimmer key or knob on the keyboard  102  may be incorporated to adjust the level of light presented to the keyboard  102 . In another example, a manual attenuator may also be implemented to adjust the illumination and/or intensity of the light. In one example, the waveguide  114  may be designed so that the further the display is tilted away from the keyboard, the more direct the illumination shines onto the keyboard  102 . The waveguide  114  may be implemented to provide a particular angle of light in the direction of the arrow  112 . The particular angle may be varied to meet the design criteria of a particular implementation. 
         [0018]    Referring to  FIG. 2 , an alternate embodiment is shown. In  FIG. 2 , a reflective element  120  has been added. The reflective element  120  may be used to direct the light  112  in a direction towards the keyboard  102 . The reflective element  120  may improve the illuminated light as directed onto the keyboard  102 . To further increase the illumination of the keyboard  102 , the reflective material  120  may be provided along the top edge of the keyboard  102 , thereby reducing the absorption of the light along the top edge of the keyboard  102 . In normal light situations, the light from the bottom or back of the backlight display LEDS may be shunted by the mirror  120 , turning off the keyboard illumination, thereby increasing the display backlight illumination. 
         [0019]    Referring to  FIG. 3 , an alternate embodiment of the computer  100  is shown. The computer  100  further comprises a light pipe  130  and a lens  132 . The light pipe  130  may be implemented, in one example, as a fiber optic cable. However, the particular type of optic cable implemented may be varied to meet the design criteria of a particular implementation. In general, the light pipe  130  may receive light at one end (from the LED backlight  108 ) and present light both along the length of the light pipe  130  and the end of the light of the light pipe  130 . The lens  132  may be implemented, in one example, as a Fresnel lens. Light from the LED backlight  108  may be directed through the light pipe  130  to the lens  132 . The lens  132  may spread to light evenly over the surface of the keyboard  102 . For example, the lens  132  may distribute the light and/or disperse the light from underneath the keyboard  102 . The light pipe  130  may extend from the upper section of the monitor  104  to the lower section of the base/keyboard  102 . The lens  132  may provide a broad light panel under the keyboard  102 . The particular placement of the light pipe  130  may be varied to meet the design criteria of a particular implementation. 
         [0020]    Referring to  FIG. 4 , a computer  200  is shown in accordance with an alternate embodiment of the present invention. The computer  200  generally comprises a display  202 , a base  204 , a keyboard  206 , a block (or circuit)  208 , an optical channel  210 , a processor  211 , a number of light pickups  212   a - 212   b,  a block (or circuit)  214 , a block (or circuit)  216 , a number of blocks (or circuits)  218   a - 218   n.  The circuit  208  may be implemented as a control circuit. The control circuit  208  may be used to control the driver circuits  214  and/or  216 . The control circuit  208  may include a processor and/or a memory. The processor of the control circuit  208  may read computer instructions that, when executed, perform one or more control functions. The circuit  214  and/or the circuit  216  may be implemented as driver circuits. The circuits  218   a - 218   n  represent the LED backlight elements. The optical channel  210  may be connected between the display  202  and the base  204 . A number of light pickups  212   a - 212   b  may be implemented. The light pickups  212   a - 212   b  may be used to sense modulated light within the light pipe  210 . In one example, one or more of the backlight LEDs  218   a - 218   n  may be dedicated to providing light to the keyboard  206 . The dedicated backlight LEDs  218   a - 218   n  may be separate devices configured to provide independent illumination control, positioning and/or design freedom. 
         [0021]    Referring to  FIG. 5 , a more detailed diagram of the computer  200  is shown. The display  202  is shown comprising an overlay  230 . The overlay  230  may include a number of sensor elements  240   a - 240   n.  The sensor element  240   a  is shown comprising a number of individual sensors  250   a - 250   n.  The particular number of sensor elements  240   a - 240   n  and the particular number of the individual sensors  250   a - 250   n  may be varied to meet the design criteria of a particular implementation. 
         [0022]    The constant current source drivers  214  and/or  216  may drive the lighting elements  218   a - 218   n  based on a pulse amplitude modulation (PAM) brightness control signal received from the circuit  208 . The touch screen overlay system  230  may detect a physical touch on the display  202 . A character (or character information) may be transmitted to a pulse phase modulator (PPM) inside the circuit  208 . The circuit  208  may modify the light pulses from the LED backlights  218   a - 218   n  based on a desired modulation. The modulation may allow the light pulses to include the character information. 
         [0023]    A “character” may include a variety of “chunks” of data. For example, a character may include information that is encoded from the touch display overlay  230  and/or used to generate the PPM signal for transmission to the detectors  212   a - 212   n.  The characters may include ANSI (or ASCII) characters, positional information related to the touch screen, events such as finger down/up, lack of events for dimming or timing out of the display brightness, etc. The particular type of information transmitted as character information may be varied to meet the design criteria of a particular implementation. 
         [0024]    The character information may be generated by changing the rate of pulses to generate a serial data stream (or serial information). The rate the pulses change is fast enough to not be noticed when viewing the display  202 . The modulated light is normally transmitted by the light pipe  210 . The main body  204  may also include photodetectors  212   a - 212   n.  The photodetectors  212   a - 212   n  may decode a serial information signal containing the character information. 
         [0025]    The computer  200  may provide a communication link that may use light from the display  202  to communicate the character information to other parts of the computer  200 . For example, the touch screen overlay  230  may sense the position of a touch. The sensors  250   a - 250   n  may be positioned around the perimeter of the overlay  230 . The sensors  250   a - 250   n  may process the touch information to be interpreted and/or used by the computer  200 . For example, the computer  200  may use touch information from the sensors  250   a - 250   n  to be encoded with the pulse phase modulator of the circuit  208 . This essentially maps information to phases of a pulse stream. The character information is generally contained in the phase of the pulses and not the amplitude. 
         [0026]    The back light for the display  202  may be controlled by pulse amplitude modulation (PPM) of the power supply. For example, to make the display  202  brighter the pulse amplitude may be increased. To make the display  202  darker, the pulse amplitude may be decreased. Changing the pulse amplitude modulation may be a technique to alter the brightness of the display  202 . The constant current source drivers  214  and/or  216  may implement the PAM brightness control. The drives  214  and/or  216  control the peripheral LED backlights  218   a - 218   n.  The wasted light (or even dedicated light) sent into the light pipe  210  may provide changes in brightness of the monitor  202  as the amplitudes changes. 
         [0027]    The computer  200  may use a PAM signal to be generated and/or modified by the circuit  208 . The circuit  208  may provide the phase modulated portion of a signal containing the desired touch character information. In general, the pulse phase of the PAM is changing. The character information may be sent independently of the brightness level of the display  202 . The desired character information may be embedded into one or more phases of the light used for backlighting. In one example, the character information may be a high level or low level pulse. Similar to an FM modulated signal, the strength of the character information may become weaker as the distance from the source increases. The character information may still be received as the signal level drops. For example, the information in the PAM and/or PPM signals is orthogonal. 
         [0028]    The particular placement of the photodetectors  212   a - 212   b  may be varied. The photodetector  212   a - 212   n  may be placed somewhere in the base  204 , under the lens  132 . Since the lens  132  spreads the light, the particular placement of the photodetectors  212   a - 212   n  may be varied to meet the design criteria of a particular implementation. The photodetectors  212   a - 212   n  normally receive the phase modulated light pulses. In general, the detected light may be used as a carrier. The phase position of the pulses may convey the character information. The character information may then be processed by the processor  211  to provide a reaction to touch information (e.g., close files, zoom in, zoom out, etc). 
         [0029]    The functions performed by the circuit  208  may be implemented using one or more of a conventional general purpose processor, digital computer, microprocessor, microcontroller, RISC (reduced instruction set computer) processor, CISC (complex instruction set computer) processor, SIMD (single instruction multiple data) processor, signal processor, central processing unit (CPU), arithmetic logic unit (ALU), video digital signal processor (VDSP) and/or similar computational machines, programmed according to the teachings of the present specification, as will be apparent to those skilled in the relevant art(s). Appropriate software, firmware, coding, routines, instructions, opcodes, microcode, and/or program modules may readily be prepared by skilled programmers based on the teachings of the present disclosure, as will also be apparent to those skilled in the relevant art(s). The software is generally executed from a medium or several media by one or more of the processors of the machine implementation. 
         [0030]    The present invention may also be implemented by the preparation of ASICs (application specific integrated circuits), Platform ASICs, FPGAs (field programmable gate arrays), PLDs (programmable logic devices), CPLDs (complex programmable logic devices), sea-of-gates, RFICs (radio frequency integrated circuits), ASSPs (application specific standard products), one or more monolithic integrated circuits, one or more chips or die arranged as flip-chip modules and/or multi-chip modules or by interconnecting an appropriate network of conventional component circuits, as is described herein, modifications of which will be readily apparent to those skilled in the art(s). 
         [0031]    The present invention thus may also include a computer product which may be a storage medium or media and/or a transmission medium or media including instructions which may be used to program a machine to perform one or more processes or methods in accordance with the present invention. Execution of instructions contained in the computer product by the machine, along with operations of surrounding circuitry, may transform input data into one or more files on the storage medium and/or one or more output signals representative of a physical object or substance, such as an audio and/or visual depiction. The storage medium may include, but is not limited to, any type of disk including floppy disk, hard drive, magnetic disk, optical disk, CD-ROM, DVD and magneto-optical disks and circuits such as ROMs (read-only memories), RAMs (random access memories), EPROMs (erasable programmable ROMs), EEPROMs (electrically erasable programmable ROMs), UVPROM (ultra-violet erasable programmable ROMs), Flash memory, magnetic cards, optical cards, and/or any type of media suitable for storing electronic instructions. 
         [0032]    The elements of the invention may form part or all of one or more devices, units, components, systems, machines and/or apparatuses. The devices may include, but are not limited to, servers, workstations, storage array controllers, storage systems, personal computers, laptop computers, notebook computers, palm computers, personal digital assistants, portable electronic devices, battery powered devices, set-top boxes, encoders, decoders, transcoders, compressors, decompressors, pre-processors, post-processors, transmitters, receivers, transceivers, cipher circuits, cellular telephones, digital cameras, positioning and/or navigation systems, medical equipment, heads-up displays, wireless devices, audio recording, audio storage and/or audio playback devices, video recording, video storage and/or video playback devices, game platforms, peripherals and/or multi-chip modules. Those skilled in the relevant art(s) would understand that the elements of the invention may be implemented in other types of devices to meet the criteria of a particular application. 
         [0033]    While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the scope of the invention.