Patent Publication Number: US-2012038689-A1

Title: Display Device and Illumination Control Method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2008-222705, filed on Aug. 29, 2008, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     An aspect of the present invention relates to a display device having an illumination and an illumination control method. 
     2. Description of the Related Art 
     For example, television broadcast receiving devices include a model in which an illumination device indicative of a company name etc. is provided on a periphery of a display portion for displaying a video and is turned ON as described in JP-A-2006-030313. A user can enjoy an ornament of a light through the illumination device and an appeal effect can be obtained for a purchaser. 
     Moreover, an electronic device such as a television broadcast receiving device usually has a power indicator indicating that a power status is ON or OFF, and a user can visually recognize a color of the power indicator, thereby recognizing the power status of the device. 
     JP-A-2006-030313 discloses that a lens sheet and a diffusing sheet are inserted between a light incident portion of a lower transparent component and a light source, that is, discloses a physical configuration of the illumination device. 
     However, how to turn ON the illumination device, for example, how to change a lighting timing or a lighting state has not been considered sufficiently. Moreover, a power illumination and an ornamental illumination could not be clearly distinguished from each other in some cases. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       A general architecture that implements the various feature of the present invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the present invention and not to limit the scope of the present invention. 
         FIG. 1  is an exemplary view for explaining an appearance of a television broadcast receiving device according to an embodiment; 
         FIG. 2  is an exemplary diagram showing a main signal processing system of the television broadcast receiving device according to the embodiment; 
         FIG. 3  is a block diagram schematically showing an example of a configuration for controlling a lighting operation of an illumination device  119  according to the embodiment; 
         FIG. 4  is an exemplary flowchart showing a lighting operation of an illumination of the television broadcast receiving device according to the embodiment; and 
         FIG. 5  is an exemplary timing chart showing the lighting operation of the illumination of the television broadcast receiving device according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments according to the present invention will be described hereinafter with reference to the accompanying drawings. In general, according to one embodiment of the present invention, there is provided a display device including: a video display unit; a housing configured to accommodate the video display unit; an illumination device provided in the housing; a power indicator provided on the housing and having a first state and a second state, the first state indicating that a power status is OFF, the second state indicating that the power status is ON; and an illumination controller configured to control the illumination device to be turned ON at a different timing shifted from a timing when the power indicator is transitioned from the first state to the second state, when the power status is transitioned from OFF to ON. 
     One embodiment according to the invention will be described below with reference to the drawings.  FIG. 1  schematically shows an example of an appearance of a television broadcast receiving device  111  which will be described in the following embodiment. 
     More specifically, the television broadcast receiving device  111  mainly includes a flat housing (hereinafter referred to as a cabinet  112 ) and a support stand  113  for erecting and supporting the cabinet  112 . The flat housing, together with the support stand  113 , may be referred to as the cabinet. The cabinet  112  is provided with, for example, a video display unit  114  to be a flat panel display including a liquid crystal display panel or a plasma panel, a pair of speakers  115 , an operating portion  116 , and a remote control receiver  118  for receiving operating information transmitted from a remote controller  117 . The operating portion  116  may be disposed on a side of the cabinet  112  in place of a front thereof. 
     Moreover, an illumination device  119  is provided under the video display unit  114  on an almost center of the front of the cabinet  112 . The illumination device  119  is provided with a character or a symbol (a logo portion) which indicates a company name or a model name, for example, and includes an LED light as a light source, for example, as will be described below. The illumination device  119  may be configured to include various patterns other than the character or the symbol. 
     Furthermore, a power indicator  120  indicative of a power status of the television broadcast receiving device  111  is provided adjacently to the remote control receiver  118  in a lower right part of the cabinet  112  shown in  FIG. 1 . The power indicator  120  also includes an LED as a light source, for example. It is also possible to employ a configuration in which the power indicator  120  is not provided adjacently to the remote control receiver  118  and an arrangement thereof is not limited. 
       FIG. 2  shows an example of a main signal processing system of the television broadcast receiving device  111 . More specifically, a satellite digital broadcasting signal received by a BS/CS digital broadcast receiving antenna  243  is supplied to a satellite digital broadcasting tuner  245  through an input terminal  244  so that a broadcasting signal for a desirable channel is selected. 
     Then, the broadcasting signal selected by the tuner  245  is supplied to a Phase Shift Keying (PSK) demodulator  246  and then a Transport Stream (TS) is demodulated. The TS is supplied to a TS decoder  247  and is thus decoded into such as digital video, voice and data signals, and they are thereafter output to a signal processor  248 . 
     Moreover, a digital terrestrial television broadcasting signal received through a terrestrial broadcast receiving antenna  249  is supplied to a digital terrestrial broadcasting tuner  251  through an input terminal  250  so that a broadcasting signal for a desirable channel is selected. 
     Then, the broadcasting signal selected by the tuner  251  is supplied to an Orthogonal Frequency Division Multiplexing (OFDM) demodulator  252  so that the TS is demodulated. The TS is supplied to a TS decoder  253  and is thus decoded into such as digital video, voice and data signals, and they are thereafter output to the signal processor  248 . 
     An analog terrestrial television broadcasting signal received through the terrestrial broadcast receiving antenna  249  is supplied to an analog terrestrial broadcasting tuner (not shown) through the input terminal  250  so that a broadcasting signal for a desirable channel is selected. The broadcasting signal selected by the tuner is then supplied to an analog demodulator (not shown) and is thus demodulated into analog video and voice signals, and they are thereafter output to the signal processor  248 . 
     Subsequently, the signal processor  248  selectively carries out a digital signal processing over the digital video and voice signals supplied from the TS decoder  247  and the TS decoder  253  respectively in television viewing, and outputs them to a graphic processor  254  and a voice processor  255 . 
     A controller  261  inputs various data for acquiring a program, electronic program guide (EPG) information, program attribute information (a program genre) and caption information (service information, SI or PSI) from the signal processor  248  and the TS decoders  247  and  253 . The controller  261  carries out an image generation processing for displaying the EPG and the caption from the input information and outputs the image information thus generated to the graphic processor  254 . 
     The graphic processor  254  has a function for superposing an On Screen Display (OSD) signal generated by an OSD signal generator  257  on the digital video signal supplied from the signal processor  248  and outputting the superposed signal. Moreover, the graphic processor  254  can selectively output the video signal output from the signal processor  248  and the OSD signal output from the OSD signal generator  257  and can send both of the outputs in combination in order to configure a half of a screen, respectively. 
     The digital video signal output from the graphic processor  254  is supplied to a video processor  258 . The video processor  258  converts the input digital video signal into an analog video signal in a format which can be displayed through the video display unit  114  and then outputs the analog video signal to the video display unit  114  to display a video, and furthermore, leads the analog video signal to an outside through an output terminal  259 . 
     Moreover, the voice processor  255  converts the input digital voice signal into an analog voice signal in a format which can be reproduced through the speaker  115  and then outputs the analog voice signal to the speaker  115  to reproduce a voice, and furthermore, leads the analog voice signal to the outside through an output terminal  260 . In addition, the television broadcast receiving device  111  includes a clock  280  for measuring a current time. 
     In the television broadcast receiving device  111 , all of operations including the various receiving operations are chiefly controlled by the controller  261 . The controller  261  includes a Central Processing Unit (CPU) and receives operating information from the operating portion  116  or receives operating information received from the remote controller  117  through the remote control receiver  118  and controls the respective portions to reflect the operating contents. 
     In this case, the controller  261  mainly utilizes a Read Only Memory (ROM)  261   a  for storing a control program to be performed by the CPU, a Random Access Memory (RAM)  261   b  for providing a work area to the CPU, and a nonvolatile memory  261   c  for storing an on-timer time, various set information and control information. 
     Moreover, the controller  261  includes a power controller  261   d.  The power controller  261   d  controls the power status of the television broadcast receiving device  111  and controls an ON/OFF operation of the power indicator  120  in response to the operations at the user operating portion  116  and the remote controller  117 . More specifically, the ON/OFF operation of the power indicator  120  is controlled as will be described below. In other words, when a main power button provided in the operating portion  116  is pressed, a state of power turns to be “ON” (ON state) and the power indicator  120  is turned ON to take on a green color, for example. Even if the state turns to be ON, a starting time is required. For this reason, a video is not displayed instantly. More specifically, a video is displayed on the video display unit  114  or a voice is output from the speaker  115  after a passage of the starting time (for example, approximately five seconds) for activating a panel power source or various signal processing circuits. When the main power button is pressed again, the power status turns to be “OFF” state and the video display and the voice output are stopped, and furthermore, the power indicator  120  is turned OFF. 
     When a power button of the remote controller  117  is pressed in the power “ON” state, moreover, the video display and the voice output are stopped and the power indicator  120  is changed from the green color to a color such as a red color or a yellow color to bring a so-called standby state in which only a part of internal circuits are operated. Furthermore, when the power button of the remote controller  117  is pressed in the standby state, the power indicator  120  is changed from the color such as the red color or the yellow color to the green color and a video is displayed on the video display unit  114  and a voice is output. In the embodiment, a state in which the video or the voice is output is set to be a power ON state (an operating state) and a state in which neither the video nor the voice is output is set to be a power OFF state. It is assumed that the power OFF state includes the standby state (in the embodiment, a state in which the power source of the television broadcast receiving device  111  is turned OFF through the power button of the remote controller  117 ) in addition to a state in which the main power source is not turned ON. Thus, the power indicator  120  has a state indicating that the power status is OFF (in the example, OFF, red and yellow) and a state indicating that the power status is ON (in the example, green). 
     Moreover, the controller  261  includes an illumination controller  261   e.  The illumination controller  261   e  controls the ON/OFF operation of the illumination device  119 . 
       FIG. 3  is a block diagram schematically showing an example of a configuration for controlling the lighting operation of the illumination device  119  through the illumination controller  261   e.    
     The illumination controller  261   e  is configured to include a Pulse Width Modulation (PWM) controller  301 . The PWM controller  301  generates a PWM control signal and outputs the PWM control signal to an integrating circuit  302  in a subsequent stage with a timing shifted by a given time after the power status is changed from OFF to ON (after the state turns to be ON state). The given time is previously recorded in a recording medium such as the nonvolatile memory  261   c,  and an oscillating circuit (not shown) carries out counting corresponding to that time, for example. After the counting for the time through the oscillating circuit is ended, the PWM control signal is output from the PWM controller  301 . In the television broadcast receiving device  111 , the power status is turned ON and various signal processing circuits and the panel power source are activated so that the video and the voice are output. However, the starting time is required as described above before the video is displayed immediately after the power status turns to be ON. If the starting time is five seconds, for example, the PWM control signal is output after counting for five seconds through the oscillating circuit. 
     The integrating circuit  302  is disposed as a delay circuit and integrates the input PWM control signal with a time, and outputs the PWM control signal thus integrated to a switch element  303  in a subsequent stage. As the integrating circuit  302 , an RC circuit is used, for example. 
     The switch element  303  carries out a switching operation in response to the input PWM control signal, thereby controlling a power supply to an LED unit  304  and a stop of the power supply. For the switch element  303 , it is possible to use a transistor element. The switching operation is carried out in response to the PWM control signal input through the integrating circuit  302 . The illumination controller  261   e  may also include the integrating circuit  302  and the switch element  303 . 
     The LED unit  304  includes some LED elements and is turned ON by a power supplied. A logo portion  305  is configured by a transparent acrylic resin material and has a character, a symbol and a pattern indicating a company name and a model name which are printed thereon. 
     Moreover, the illumination controller  261   e  carries out a control for always turning OFF the lighting operation of the illumination device  119  in response to a user operation. More specifically, when a dark video such as a movie is to be viewed and the user does not want the illumination device  119  to be ON, it is possible to select OFF setting of the illumination device  119  by displaying a menu screen on the video display unit  114  through the remote controller  117  and operating the menu screen. In the embodiment, thus, it is possible to select, based on the user operation, an ON mode in which the illumination device  119  is turned ON in the power ON state and an OFF mode in which the illumination device  119  is not turned ON in the power ON state. In the ON mode, it is possible to further provide a mode in which the illumination device  119  is turned ON in a lower luminance than usual. 
     Although the power indicator  120  is continuously maintained to be ON with a change in a lighting color to the red color, for example, in the standby state of the television broadcast receiving device  111  in the embodiment, moreover, the illumination device  119  is turned OFF. 
     Next, the lighting operation of the illumination device  119  of the television broadcast receiving device  111  according to the embodiment will be described with reference to a flowchart of  FIG. 4  and a timing chart of  FIG. 5 . 
     First of all, a power ON operation is carried out at the user operating portion  116  or the remote controller  117  (for example, the main power button provided in the operating portion  116  is pressed or the power button of the remote controller  117  is pressed in the standby state) (Step  401 ). 
     Consequently, the controller  261  outputs a control signal (a power ON signal) for bringing the television broadcast receiving device  111  into the ON state to a liquid crystal panel and various signal processing circuits (Step  402 ). When the power ON signal is supplied, the liquid crystal panel and the signal processing circuits start operations and a processing for outputting a video and a voice is performed. Simultaneously with the output of the power ON signal, the television broadcast receiving device  111  turns to be the ON state and the color of the power indicator  120  is changed into the green color, for example (see  FIG. 5 , sections (a) and (b)). Although the power indicator  120  is turned ON, the illumination device  119  has not been turned ON at this time. 
     Next, an oscillating circuit (not shown) counts a time after the power ON signal is output (Step  403 ). When the counting corresponding to the time stored in the nonvolatile memory  261   c  is ended, then, the PWM controller  301  outputs the PWM control signal to the integrating circuit  302  in the subsequent stage (Step  404 ). In other words, a timing is shifted by a preset time after the power source turns to be the ON state and the PWM control signal is supplied to the integrating circuit  302  in the subsequent stage. Consequently, the lighting timings of the power indicator  120  and the illumination device  119  are shifted from each other. 
     Subsequently, the switch element  303  is gradually brought into the ON state with a delay of the PWM control signal through the integrating circuit  302 . Therefore, a current flowing to the LED element in the LED unit  304  is slowly increased and the LED element is correspondingly brightened slowly. Then, a certain brightness is obtained. Thereafter, the logo portion  305  is illuminated by the light of the LED element and is thus brightened slowly (Step  405 ). Consequently, it is possible to obtain an intended ornamental effect. 
     When there is employed a configuration in which the starting time required for displaying a video immediately after the television broadcast receiving device  111  turns into the ON state is five seconds, for example, and the PWM control signal is output after counting an equal time (five seconds) to the starting time, the illumination device  119  is turned ON almost simultaneously with the display of the video. Thus, the illumination device  119  is turned ON almost simultaneously with the display of the video or corresponding to the fact that the video in a dark condition is brightened slowly ( FIG. 5 , sections (c) and (d)). By turning ON the power indicator and the illumination in different timings, accordingly, it is possible to clearly distinguish the power indicator intended for indicating the power status from the illumination intended for the ornamental effect. Moreover, the user can be prevented from having an uncomfortable feeling that the illumination device  119  is ON though the video is not displayed.  FIG. 5 , section (c) shows a situation in which the display of the video makes a transition in such a manner that a dark video is gradually brightened after a passage of the starting time. Moreover,  FIG. 5 , sections (d) to (f) show a situation in which the illumination is turned ON to be gradually brightened after a passage of a time. 
     It is also possible to employ a configuration in which the timing is not taken with the time by using the oscillating circuit but the illumination controller  261   e  controls the output of the PWM control signal and the lighting operation of the illumination device  119  is controlled when a back light is turned ON and a video signal is supplied to a panel in case of a liquid crystal TV, for example. More specifically, it is also possible to employ a configuration in which the controller  261  detects that the video is displayed and the lighting operation of the illumination device  119  is controlled based on the detection. With the configuration, the illumination device  119  is started to be turned ON almost simultaneously with the display of the video. Thus, it is possible to propose various manners for the control of the lighting operation of the illumination device  119 , for example, a manner for using the oscillating circuit or a manner for using the detection of the display of the video. 
     A luminance level of the illumination device  119  may be set and changed according to a user&#39;s preference over the operating menu screen. 
     The illumination device  119  starts the lighting operation before the video is displayed and the illumination device  119  is turned ON before the video is displayed when there is employed a configuration in which the starting time is five seconds, for example, and the PWM control signal is output after counting for a shorter time (for example, four seconds) than the starting time, moreover. Thus, it is also possible to employ a configuration in which the illumination device  119  is started to be turned ON before the video is displayed (see  FIG. 5 , sections (c) and (e)). With the configuration, the illumination is turned ON before the video is displayed but starts the lighting operation with a passage of a period after it is brought into the ON state. Therefore, it is possible to reduce an uncomfortable feeling that the illumination is turned ON though the video is not displayed. 
     When there is employed a configuration in which the starting time is five seconds, for example, and the PWM control signal is output after counting for a longer time (for example, six seconds) than the starting time, furthermore, the illumination device  119  starts the lighting operation after the video is displayed. Thus, it is also possible to employ a configuration in which the illumination device  119  is started to be turned ON after the video is displayed (see  FIG. 5 , sections (c) and (f)). Accordingly, it is possible to prevent the user from having an uncomfortable feeling that the illumination is turned ON though the video is not displayed. 
     Moreover, when the illumination device  119  is set to be OFF by the user operation, the illumination device  119  is always turned OFF irrespective of the power status (see  FIG. 5 , section (g)). 
     As described above, in the embodiment, the lighting timings of the power indicator and the illumination are shifted from each other. Therefore, the illumination is clearly distinguished from the power indicator indicative of the power status so that the user can be prevented from having the uncomfortable feeling that the illumination is turned ON though the video is not displayed. Moreover, by providing the OFF setting of the illumination device  119 , the user can easily set the illumination to be OFF even if he (she) does not desire the lighting operation of the illumination when a dark scene of a movie is to be viewed at home. Since the user can be prevented from feeling that the illumination device  119  is an obstacle to the view or is dazzling, he (she) can concentrate on an appreciation of a video. 
     In the embodiment, moreover, there is employed the configuration in which the illumination is gradually brightened from a dark state. Therefore, it is possible to prevent a viewer from having an uncomfortable feeling without disturbing a feeling that the video is displayed. 
     The invention is not exactly restricted to the embodiment but the components can be changed to be concrete without departing from the scope in an implementing stage. By a proper combination of the components disclosed in the embodiment, moreover, it is possible to form various inventions. For example, in the embodiment, the illumination device  119  is gradually brightened in the lighting operation by the configurations of the PWM controller  301  and the integrating circuit  302 . However, it is also possible to employ a configuration in which a rising speed can be increased without providing the integrating circuit  302  and the illumination device  119  can be quickly brightened with a passage of a time in the power ON state. Although the brightness is constant after the lighting operation of the illumination device  119  in the embodiment, moreover, it is also possible to dynamically change the brightness of the illumination device  119  in the power ON state. Moreover, it is possible to change the lighting colors of the illumination and the power indicator depending on a light emitting element to be used. 
     Although the illumination device  119  is OFF in the standby state in the embodiment, moreover, the illumination device  119  may be turned ON in the standby state or a mode having a lower luminance than usual may be provided. Moreover, it is also possible to employ a configuration in which the illumination device  119  is caused to flash in the power ON state.