Abstract:
An electronic device and method of illuminating a display are provided. The electronic device includes a display device, an illumination device, a light sensor and a processor coupled to the illumination device and the light sensor. The processor receives a light value from the light sensor, determines a target illumination value based at least partly on the light value, and causes the illumination device to illuminate the display device at substantially the target illumination value. In one embodiment, the processor causes the illumination device to illuminate the display device at substantially the target illumination value by gradually increasing a current illumination value. In another embodiment, the processor causes the illumination device to illuminate the display device at substantially the target illumination value by gradually decreasing a current illumination value.

Description:
[0001]     This application claims the benefit of U.S. Provisional Application Ser. No. 60/544,594, filed Feb. 13, 2004, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to lighting device or lighting apparatus for a video game device and specifically, to a backlight device for a video game device that automatically adjusts the light intensity level of the display screen of the video game device to enable players to view and play a game displayed by the display screen in different lighting conditions.  
       BACKGROUND OF THE INVENTION  
       [0003]     In the video game industry, there are several different types of video game devices. Certain video game devices or systems connect to a television set and operate games which are displayed on the television screen. Other video game devices are handheld devices which enable players to carry the devices with them and play games at different locations and in different settings. The handheld devices include video screens or video displays which display the games operated by these devices. Conventional video screens or video displays for the handheld devices typically include a Liquid Crystal Display (LCD) which displays the images of the games operated by the handheld devices.  
         [0004]     One problem with conventional LCD&#39;s is that the LCD&#39;s are difficult to view in different lighting conditions such as in very low light or no light conditions. In these situations, players must move to a different area which has more favorable lighting conditions to view and play the games displayed by the LCD&#39;s of the handheld devices. As a result, players are limited by the lighting conditions of the particular location or place in which they are using the video game device and in some instances, the players are limited by the time of day which they can view and play the games operated by the handheld devices.  
         [0005]     To overcome this problem, some conventional handheld devices include separate lights which are attachable to the handheld devices to illuminate the LCD displays and enable players to use the devices in low to no light conditions. Certain of these lights are separate external lights which are attached to a handheld device to project light down or at the LCD display of the device. Some of these external lights are connected to a cover or other similar panel which is attached adjacent to and over the LCD display. Other external lights are mounted to a bracket or arm which is attached to and extends above the console of the handheld device. The bracket or arm includes a light source at one end and positions the lights source above the LCD display. The light source emits light which projects down onto the LCD display similar to a book light. These lights tend to cause glares or reflections which affect the players&#39; ability to view and play the games displayed on the LCD displays.  
         [0006]     Certain other handheld devices employ an internal backlight device or system which includes one or more Light Emitting Diodes (LED&#39;s) to illuminate the LCD display. The backlight is installed between the LCD and the front protective lens of the handheld device. A switch or other control is typically connected to the backlight to control and adjust the brightness of the backlight and also to turn the backlight on and off. The internal backlight, however, requires complicated installation procedures. Additionally, the internal backlight requires that players manually adjust the control or switch each time they want to adjust the brightness level of the backlight device. If the ambient light conditions become darker while players are playing the handheld device, the players are forced to adjust the brightness or light intensity level of the backlight device while they are playing a game to adequately view the display of the handheld device. Adjusting the backlight in this manner interrupts a player&#39;s concentration level and affects the player&#39;s ability to play the game operated by the handheld device.  
         [0007]     A further problem with these backlight devices is that the backlight devices illuminate the display screen to the highest or greatest light intensity level. The light intensity level can then be adjusted or modified using a control or switch which is manually adjusted by the player. However, if the player does not adjust the light intensity level or if the light intensity level consistently remains at a high level, the batteries or the stored energy used to power the video game device are depleted at a faster rate, resulting in less playing time.  
         [0008]     Accordingly, there is a need for a lighting device for a video game device which automatically adjusts the light intensity of the video game display according to different lighting conditions and conserves the energy used to power the video game device.  
       SUMMARY OF THE INVENTION  
       [0009]     In one embodiment of the present invention, an electronic device includes a display device, an illumination device, a light sensor and a processor coupled to the illumination device and the light sensor. The processor receives a light value from the light sensor, determines a target illumination value based at least partly on the light value, and causes the illumination device to illuminate the display device at substantially the target illumination value. In one embodiment, the processor causes the illumination device to illuminate the display device at substantially the target illumination value by gradually increasing a current illumination value. In another embodiment, the processor causes the illumination device to illuminate the display device at substantially the target illumination value by gradually decreasing a current illumination value.  
         [0010]     In one embodiment, the processor determines the target illumination value if the processor determines the light value exceeds a preset value. In another embodiment, the processor determines the target illumination value if the processor determines the light value is less than a preset value. In still another embodiment, the target illumination value is selected from the group consisting of a minimum illumination value, a maximum illumination value, and an intermediate illumination value wherein the intermediate illumination value is between the maximum illumination value and the minimum illumination value.  
         [0011]     In one embodiment, the processor determines the target illumination value by applying a mapping function. In another embodiment, the electronic device also includes an illumination level adjustment input device coupled to the processor. The processor determines a second illumination value based at least partly on an adjustment value received from the illumination level adjustment input device and causes the illumination device to illuminate the display device at substantially the second illumination value. In another embodiment, a mapping function maps the light value to the second illumination value. In still another embodiment, the electronic device is selected from the group consisting of a video game device, a handheld video game device, a personal digital assistant, a lap top computer, a cellular phone, a portable DVD player, and a computer.  
         [0012]     In another embodiment, a video game device includes a housing, a display device mounted to the housing, an illumination device positioned adjacent to the display device, a light sensor mounted to the housing and in communication with the illumination device and a processor. The processor is operable to automatically activate the illumination device, cause the illumination device to gradually emit light until a designated light intensity level is achieved, cause the light sensor to detect the ambient light intensity level and modify the light intensity level of the light emitted by the illumination device to the designated light intensity level based on the detected ambient light intensity level.  
         [0013]     Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the figures. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0014]      FIG. 1  is a perspective view of a handheld video game device including a video display employing a light display in accordance with one embodiment of the present invention.  
         [0015]      FIG. 2  is a schematic block diagram illustrating the operation of the light display system of the handheld video game device of  FIG. 1 .  
         [0016]      FIG. 3  is a schematic diagram of the electronic configuration of the light display system of the handheld video game device of  FIG. 1 .  
         [0017]      FIG. 4  is a flow diagram of the process of illuminating a display device in accordance with one embodiment of the present invention.  
         [0018]      FIG. 5  is a flow diagram of the process of adjusting a mapping function when a display illumination level is manually adjusted in accordance with one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Referring now to  FIGS. 1, 2  and  3 , in one embodiment of the present invention, a display illumination system, including a lighting device or light source such as backlight device  126 , is employed in a handheld video game device  100 . While the light source is preferably a backlight device  126 , any suitable light source can be used. The handheld video game device  100  includes a housing  103 , a processor mounted in the housing and a display mounted to the housing and controlled by the processor. It should be understood that a processor can be any suitable electronic circuit. The display is preferably a video display or video screen  102 ; however it can be any other suitable display device. Preferably, the handheld video game device  100  also includes a plurality of inputs  104 ,  106 ,  108  and  110 , which are mounted to the housing and controlled by the processor, and a photoconductive sensor or light sensor  111  which is mounted on a surface of the housing or positioned in any other suitable location. The photoconductive sensor or light sensor  111  is in communication with the processor and is adapted to detect an ambient light intensity level. Sensor  111  is also in communication with an illumination device such as backlight device  126  positioned adjacent to the screen  102  that is also in communication with the processor.  
         [0020]     The illumination device, backlight device or backlight display  126  can be automatically adjusted such that the light intensity level of the video display or video screen enables players to view and play a game displayed by the handheld video game device in different ambient light conditions. Therefore, players are able to enjoy and play the games with little or no affect on their concentration or their ability to play the games.  
         [0021]     In one embodiment, the display device or display screen  102  includes a Liquid Crystal Display (LCD) that displays the characters, symbols or images of a particular game when the game is operated by the handheld device. Preferably, the LCD is mounted to the housing  103  and is visible by a player from the front or top portion of the handheld device as illustrated in  FIG. 1 ; however the LCD can be arranged in any suitable configuration. The LCD or display screen  102  may display black and white images, color images or any suitable combination of these colors or images. It should be appreciated that the display screen  102  does not necessarily need to be an LCD and may be any suitable display device or display screen.  
         [0022]     Preferably, the backlight device  126  includes a conventional backlight device such the backlight devices available at video game stores or retailers; however, the backlight device  126  can be any suitable backlight device. The backlight device  126  is preferably internally mounted to the housing  103  of the handheld device  100 ; however the backlight device  126  can be configured in any suitable manner. Specifically, the backlight device  126  is positioned adjacent to and between the display device or display screen  102  of the handheld device  100  and the processor (i.e., printed circuit board, PC board or other suitable device). The processor activates the backlight device to increase the light intensity level of the display screen  102  in low or no light conditions. It should be appreciated that the light intensity level of the light emitted from the backlight device  126  is adjustable to any suitable light intensity level or to any desired light intensity level by the processor.  
         [0023]     Preferably, the handheld device  100  includes a photoconductive sensor or light sensor  111  which is mounted to the housing  103 ; however, the photoconductive sensor or light sensor  111  is not necessarilty mounted (e.g., a remote sensor not mounted to the housing) and can be arranged in any other suitable manner. The handheld device preferably includes one photoconductive sensor  111 , but can include any suitable number of photoconductive sensors  111 . It should also be appreciated that the photo conductive sensor  111  may be mounted to any suitable location or locations on the housing  103 . The photo conductive sensor may also be an independent sensor which is attachable to a surface of the housing  103 .  
         [0024]     The photoconductive sensor  111  detects or senses the ambient light intensity level and communicates the detected light intensity level to the processor. Then, the processor compares the detected light intensity level with a designated, pre-determined or preset light intensity level that is inputted or programmed into the processor during manufacturing of the handheld game device or any other suitable time. It should be noted that the player can specify the preset light intensity level. Further, the preset light intensity level could be derived or learned from the player&#39;s behavior (e.g., the player manually adjusting the display illumination in one or more ambient light circumstances). Preferably, the designated light intensity level is determined or set based on a desired or optimum light intensity level for viewing the display device or display screen of the handheld device  100  in low to no light conditions; however, the designed, predetermined or preset light intensity level can be set to any suitable light intensity level.  
         [0025]     Preferably, the handheld device  100  includes a capacitor such as a time delay capacitor  124 , which is mounted to the processor or PC board; however, the handheld device  100  can operate in accordance with various embodiments of the present invention without a capacitor such as the time delay capacitor  124 . The time delay capacitor  124  can be any suitable capacitor. Preferably, the time delay capacitor  124  is electrically connected between the photo conductive sensor  111  and the backlight device  126  as illustrated in  FIG. 3 ; however, the time delay capacitor  124  can be connected in any other suitable configuration or absent from the handheld device  100  entirely.  
         [0026]     The time delay capacitor  124  receives the electrical signals from the photo conductive sensor (which indicates the ambient light intensity level) and adjusts the signals so that the backlight display gradually illuminates until the designated or desired light intensity level is reached. Therefore, the time delay capacitor prevents the backlight display from automatically illuminating to the highest light intensity level or brightest light setting such as what commonly occurs with the backlight device in a typical cellular phone or similar device. The gradual illumination of the display screen (i.e., LCD) enables the backlight device  126  to illuminate the display screen to several different light intensity levels.  
         [0027]     Further, the gradual change in backlight level can make the change less noticeable to the game player and/or to others. Thus, the game player is less likely to be distracted from the game by abrupt backlight level changes, and backlight level changes are less likely to draw the attention of others. As a result, the backlight device enhances the visual display of the game and increases a player&#39;s enjoyment of the video game device.  
         [0028]     Additionally, the gradual illumination of the backlight device efficiently utilizes the stored energy, such as the energy stored in one or more batteries inserted in the device, to operate the handheld device. This conserves energy and thereby enables the batteries, or other energy source that powers the handheld device, to last longer and enable players to play the games for a longer period of time while using the backlight device.  
         [0029]     Preferably, after a player activates or turns the handheld device “on,” the processor automatically causes the photoconductive sensor  111  to sense or detect the ambient light intensity level of the particular location or setting in which a player is using the handheld device, and automatically causes the backlight device or backlight display to automatically, gradually adjust the light intensity level of the display screen  102  according to the detected ambient light intensity level. However, it should be noted that operation of the photoconductive sensor  111  can be initiated and/or conducted manually or in any other suitable manner.  
         [0030]     Preferably, the backlight device of the present invention continuously and gradually adjusts the light intensity level of the display screen of the video game device to a designated optimum light intensity level based on the detected ambient light conditions of the surroundings in which the player is playing a game operated by the handheld device; however, the light intensity level can be adjusted at regular intervals or in any other suitable manner. The present invention therefore enables players to continue to play games operated by the handheld device without interruption and at substantially optimum or ideal light intensity levels for viewing and playing the games on the display screen.  
         [0031]     When the ambient light intensity level is less than the preset or designated light intensity level as shown in block  116 , the processor gradually increases the light intensity level of the light emitted by the backlight device  126 . Similarly, the processor gradually decreases the light intensity level of the light emitted by the backlight device  126  when the ambient light intensity level is greater than the designated or preset light intensity level as shown in block  112 .  
         [0032]     Further, when the ambient light intensity level is greater than the designated light intensity level, the processor causes the time delay capacitor to charge up. As a result, the backlight device gradually emits light and gradually illuminates the display screen  102 . Once the capacitor is fully charged, the backlight device illuminates at the target illumination level (e.g., maximum illumination or another predetermined level). When the ambient light intensity level is less than or below the designated light intensity level, the processor causes the time delay capacitor to discharge. Once the capacitor is fully discharged, the backlight device illuminates at the target illumination level (e.g., no illumination or another predetermined level). Operating the handheld device in this manner saves significant power and enables the batteries or other energy source used to operate the video game device to last longer.  
         [0033]     Referring now to  FIG. 3 , the preferred electrical or electronic configuration of the components of the handheld device is shown; however the components of the handheld device can have any suitable electrical or electronic configuration. The photo conductive sensor  111  is electrically connected to the time delay capacitor  124  which controls the illumination of the backlight device. The capacitor  124  is also electrically connected to the backlight device  126 . Thus, the electrical signals indicating the ambient light intensity level sensed by the photoconductive sensor  111  are relayed or communicated to the backlight device  126  via electrical wires or any suitable electrical communication lines or means. The capacitor adjusts the time delay of the electrical signals to increase or decrease the light intensity level of the backlight device based on the ambient light intensity level detected or sensed by the photoconductive sensor  111  as described above. It should be appreciated that the electrical configuration of the present invention may include any suitable number of resistors, capacitors or other electrical components. Further, it should be appreciated that the display illumination system can be electrically or electronically separate from the system that controls the game.  
         [0034]      FIGS. 4 and 5  show the operation of an alternative embodiment in which the display and backlight device  126  (or any other display illumination device or method) are maintained to the extent possible at an effective brightness level. Both an ambient light scale and a backlight scale are determined. Preferably the ambient light scale ranges from no ambient light to the maximum detectable by the photoconductive sensors  111 ; however the ambient light scale can have any suitable range. Similarly, the backlight scale preferably ranges from off to maximally on; however, the backlight scale can have any suitable range. A mapping function maps ambient light values to backlight values. Preferably, the mapping function is linear; however the mapping function can be any suitable mapping from ambient light values to backlight values. It should be noted that backlighting is discussed for illustrative purposes and that any other illumination devices and/or methods can be used in accordance with alternative embodiments of the present invention.  
         [0035]     As shown in  FIG. 4 , as the ambient light level detected by the photoconductive sensors  111  changes, the amount of light supplied by the display illumination or brightness system also changes. When a handheld video game device  100  is turned on, at step  400  the photoconductive sensors detect the ambient light level. From the ambient light level a target illumination level is determined (e.g., using the mapping function) at step  405 . Then, at step  410 , it is determined whether the current illumination level is lower than the target illumination level. If it is, the current illumination level is increased at step  415  and the process repeats at step  400 . Preferably, the current illumination level is increased directly to the target illumination level; however, the current illumination level can be increased by an increment, by a gradual increase towards maximally on using a time delay capacitor  124  as described above, or in any other suitable manner.  
         [0036]     If the current illumination level is not lower than the target illumination level, at step  420 , it is determined whether the current illumination level is higher than the target illumination level. If it is, the current illumination level is decreased at step  425  and the process repeats at step  400 . Preferably, the current illumination level is decreased directly to the target illumination level; however, the current illumination level can be decreased by an increment, by a gradual decrease towards off using a time delay capacitor  124  as described above, or in any other suitable manner. If the current illumination level is not higher than the target illumination level, the levels must be equal, so the level is not adjusted and the process repeats at step  400 .  
         [0037]     Additionally, the processor is preferably programmable to check the ambient light constantly or at specific time intervals, and repeats the process described above and shown in  FIG. 4 . Thus, if the ambient light level changes, the illumination level is adjusted only as much as needed (i.e., the amount indicated by the mapping function).  
         [0038]     As shown in  FIG. 5 , the game player or user, preferably, can manually select a brightness level for the display illumination system at step  500 . The selection is preferably made by moving a dedicated dimmer switch; however, the selection can be made using a combination of software and one or more general input devices (e.g., adjustment of various laptop monitors by invoking a display brightness adjustment mode and pressing the left/right or up/down cursor keys to raise or lower the brightness level) or any suitable selection device. It should be noted that the level selected by the game player or user can be sub-optimal for battery efficiency purposes.  
         [0039]     Further, the level selected can be inconsistent with a mapping function given the current ambient light level. To reconcile this possible inconsistency, if the player selected illumination level is different from the illumination level determined by the current ambient light level and the mapping function, the mapping function is changed so that the current ambient light level maps to the player selected illumination level at step  505 . Preferably, the function is changed by adding or subtracting a scalar value. For example, if the mapping function, map(x), maps the current ambient light level to an illumination level that is c units below the player selected illumination, the new mapping function, new_map(x), is map(x)+c. It should be noted that the new mapping function can be any suitable mapping function. Then, at step  510 , the new mapping function is used to control the display device illumination level.  
         [0040]     The handheld video game device  100  can also include an override mechanism that enables a user to specify that the display illumination level should not change even if the ambient light level changes. Further, the mapping function and/or preset light intensity level can be programmed using any suitable means. Thus, a user can specify the exact display illumination behavior desired in any number or range of ambient light intensity levels.  
         [0041]     It should be appreciated that the present invention is not limited to video game devices such as handheld video game devices and may be employed in any suitable devices such as personal digital assistants, portable computers or lap top computers, blackberry devices, cellular phones, portable DVD players or any suitable electronic, electrical, video display device or other suitable display device which utilizes a display screen to display images, symbols, characters or other data or information to a user.  
         [0042]     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.