JP2011139359A - Display device, stopping method, program, and recording medium - Google Patents

Abstract

Provided is a display device capable of reducing power consumption while responding to a viewer's desire to view a video while staying at a remote place.
A display device according to the present invention is a display device that displays an image in a normal mode or a power saving mode, and when a dead time in which the presence of a viewer is not detected by a human sensor exceeds a first threshold, The luminance adjustment unit 103 and the volume adjustment unit 104 that switch the operation mode of the display device from the normal mode to the power saving mode, and the video display automatically stop when the dead time exceeds the second threshold value that is larger than the first threshold value. Power supply control unit 105.
[Selection] Figure 1

Description

  The present invention relates to a display device including a device for detecting the presence of a person and a method for stopping the display device.

  In recent years, reduction of power consumption is becoming an added value of home appliances, and reduction of power consumption is also demanded for televisions (television receivers). As a technique for reducing power consumption in a television, a technique is known in which video and / or audio output is automatically stopped when there is a high possibility that a viewer is not watching a video.

  For example, Patent Document 1 discloses a technique for automatically stopping video and audio output when a viewer has been away from the television for a certain period of time.

  Further, in Non-Patent Document 1, video output is automatically stopped when a certain time has elapsed since the viewer left the television, and then the viewer does not return to the television and is further constant. A technique for automatically stopping audio output when time elapses is disclosed.

  Although it is not a technology aimed at reducing power consumption, Patent Documents 2 and 3 describe whether or not the viewer is in front of the TV and whether or not the surrounding illuminance is brighter than the reference illuminance. Thus, a technique for controlling a television is disclosed.

JP-A-6-78246 (published March 18, 1994) JP 2004-120049 A (released on April 15, 2004) JP 2008-252526 A (released on October 16, 2008)

[Online], Sony (searched on November 13, 2009), Internet <http://www.sony.jp/bravia/shoene/index02.html>

  According to the technique described in Patent Document 1, when a viewer leaves the television for a certain time or longer, the television stops outputting video and audio. For this reason, the technique described in Patent Document 1 wants to enjoy a program while staying in a remote place (outside the range of the human sensor) (for example, wanting to watch a television set in the living room while cooking in the kitchen) ).

  On the other hand, according to the technique described in Non-Patent Document 1, when the viewer leaves the television for a certain time or more, the television stops only the video output (the audio output does not stop). For this reason, the viewer can listen to the audio of the program even if he / she is away (outside the detection range of the human sensor). However, if it is in a remote place (outside the detection range of the human sensor), the viewer cannot view the video of the program. For this reason, when the user listens to the voice and wants to watch the program, the user cannot feel the program and feels stressed.

  The present invention has been made to solve the above-described problems, and its main purpose is to reduce power consumption while responding to viewers' desire to view video while being at a remote location. It is to realize a display device that can be used.

  In order to solve the above problem, a display device according to the present invention is a display device that displays an image in the first mode or the second mode that consumes less power for displaying an image than the first mode. If the length of the dead time in which the presence sensor is not detected by the human sensor and the human sensor exceeds the first threshold, the operation mode of the display device is changed from the first mode to the second mode. And a mode switching means for switching to the mode, and a stop means for automatically stopping the display of the video when the dead period exceeds a second threshold value that is greater than the first threshold value. To do.

  According to the above configuration, the human sensor does not detect the presence of the viewer (that is, the viewer is not in the vicinity of the display device) and the second period after the length of the dead time exceeds the first threshold. Until the threshold value is reached, the power consumed to display the video can be reduced. Further, after the length of the dead period exceeds the second threshold, it is not necessary to consume power to display the video.

  In addition, according to the above configuration, since the length of the dead period exceeds the first threshold and then reaches the second threshold, the video continues to be displayed in the second mode. Like the described technology, the pleasure of watching the video is not lost.

  Note that when viewing a video displayed on a display device from a remote location (for example, when watching a television set in a living room while cooking in a kitchen), the viewer's demand for image quality is low. For this reason, in the insensitive period in which the presence sensor does not sense the presence of the viewer, the viewer may be dissatisfied even if the video is displayed in the second mode in which the power consumption required for displaying the video is small. Absent.

  In the display device according to the present invention, it is preferable that the luminance of the video displayed in the second mode is lower than the luminance of the video displayed in the first mode.

  According to said structure, when the said display apparatus operate | moves in the said 2nd mode, the power consumption required for the display of the said image | video can be reduced.

  In the case where the display device is a transmissive liquid crystal display device, for example, the luminance of the displayed image can be reduced by reducing the light amount of the backlight.

  In the display device according to the present invention, it is preferable that the size of the image displayed in the second mode is smaller than the size of the image displayed in the first mode.

  According to said structure, when the said display apparatus operate | moves in the said 2nd mode, the power consumption required for the display of the said image | video can be reduced more.

  When the display device is a transmissive liquid crystal display device having a backlight capable of area driving (local dimming), for example, by reducing the lighting range of the backlight, the size of the displayed image can be reduced. Can do.

  In the display device according to the present invention, it is preferable that the display device further includes a volume reduction unit that reduces the volume of the audio output accompanying the video when the length of the dead time exceeds the first threshold. .

  According to the above configuration, when the display device operates in the second mode, power consumption required for displaying the video can be reduced and power consumption required for audio output (for example, power consumption of an amplifier). Can be reduced.

  When the length of the dead period exceeds the first threshold, it is preferable to further include an audio stop unit that partially stops the output of the audio accompanying the video.

  According to said structure, when the said display apparatus operate | moves in the said 2nd mode, while being able to reduce the power consumption required for the said video display, the power consumption required for an audio | voice output can be reduced.

  In the display device according to the present invention, it is preferable that the stop means stops outputting the sound accompanying the video when the length of the dead period exceeds the second threshold.

  According to the above configuration, in a situation where it is highly likely that the viewer has not watched or heard the video displayed on the display device, the waste of electric power due to the display device continuing to output sound is prevented. can do.

  In the display device according to the present invention, it is preferable that the stopping means automatically stops the operation of the external device when the length of the dead period exceeds the second threshold value.

  According to the above configuration, it is possible to automatically stop the operation of the external device at the same time as the video display is automatically stopped. Accordingly, it is possible to prevent waste of electric power that is caused by continuing to operate the external device even though the viewer is not using the external device.

  In the display device according to the present invention, the stop means may detect a viewer by the human sensor until a predetermined time elapses after the power supply to the human sensor is started. Regardless of whether or not there is a viewer, it is preferable to operate as if there is a viewer.

  According to the above configuration, the motion of the motion sensor becomes unstable, and a viewer exists for a while from the time when power is supplied to the motion sensor, regardless of the detection result of the motion sensor. The display device can be operated. As a result, the presence of the viewer in the unstable period from when the electric power is supplied to the human sensor until a predetermined time elapses is not detected by the human sensor, so that the display device Can be prevented from being switched to the second mode, and the display being automatically stopped.

  A stop method according to the present invention is a stop method for stopping display of an image on a display device provided with a human sensor, and the length of a dead period during which the presence of a viewer is not detected by the human sensor is first. When the threshold is exceeded, a mode switching step of switching the operation mode of the display device from the first mode to the second mode, and when the dead time exceeds a second threshold greater than the first threshold, And a stop step of automatically stopping the display of the video.

  According to the above configuration, it is possible to reduce the power consumed to display the video from the time when the length of the dead period exceeds the first threshold until the second threshold is reached. Further, no power is required to display the video after the length of the dead period exceeds the second threshold.

  In addition, according to the above configuration, since the length of the dead period exceeds the first threshold and then reaches the second threshold, the video continues to be displayed in the second mode. Like the described technology, the pleasure of watching the video is not lost.

  A program for operating the display device according to the present invention, which is a program that causes a computer to function as each of the above-described means, and a computer-readable recording medium that records the program are also provided. It is included in the category of the invention.

  As described above, the display device according to the present invention switches the operation mode of the display device from the first mode when the length of the insensitive period in which the presence of the viewer is not detected by the human sensor exceeds the first threshold. When switching to the second mode, which consumes less power than the first mode, and when the dead time exceeds the second threshold value, which is greater than the first threshold value, the video display is automatically stopped. It is possible to reduce power consumption while responding to the viewers' desire to view images while outside the human sensor.

It is a block diagram which shows the principal part structure of the control part with which the display apparatus which concerns on embodiment of this invention is provided. It is a block diagram which shows the principal part structure of the display apparatus which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the control part with which the display apparatus which concerns on embodiment of this invention is provided. It is a state transition diagram of a display device concerning an embodiment of the present invention.

  A display device according to an embodiment of the present invention will be described as follows with reference to FIGS.

(Configuration of display device)
First, the configuration of the display device 10 according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating a configuration of the display device 10.

  The display device 10 (display device) is a television receiver, and as shown in FIG. 2, a memory 7, an analog tuner unit 12, a digital tuner unit 14, a digital demodulation unit 15, a separation unit 16, a video decoding unit 17, Video selector unit 18, video processing unit 19, display control unit 21, liquid crystal display device 22, IP broadcast tuner unit 23, EPG / OSD processing unit 24, audio decoding unit 25, audio selector unit 26, audio output conversion unit 27, speaker 28, external input unit 31, recording / playback unit 32, channel selection unit 33, communication control unit 34, remote control light receiving unit 35, OPC (RGB) sensor 51 (illuminance sensor), human sensor (heat sensor) 52 (human sensor) , A power supply unit 53, and a control unit 100. The display device 10 is configured to be connectable to the antenna 11, the antenna 13, and the external device 30 (external device), and can be operated by the remote controller 36.

  The analog tuner unit 12 extracts the video signal and the audio signal superimposed on the channel selected by the channel selection unit 33 from the analog broadcast signal received by the antenna 11, and supplies the extracted video signal to the video selector unit 18. At the same time, the extracted audio signal is supplied to the audio selector unit 26.

  The digital tuner unit 14 extracts a digital signal superimposed on the channel selected by the channel selection unit 33 from the digital broadcast signal received by the antenna 13 and supplies the extracted digital signal to the digital demodulation unit 15. The digital demodulation unit 15 generates stream data in a predetermined format (for example, MPEG2-TS format) from the digital signal extracted by the digital tuner unit 14 and supplies the generated stream data to the separation unit 16.

  The IP broadcast tuner unit 23 acquires the stream data of the content selected by the channel selection unit 33 from an external device (for example, a server device) connected via the network, and supplies the acquired stream data to the separation unit 16 To do. Acquisition of stream data by the IP broadcast tuner unit 23 is performed via the communication control unit 34. The network is not particularly limited. For example, a network using a telephone line, a LAN, an HDMI cable, or the like can be given.

  The external input unit 31 reads out the video signal and the audio signal recorded in the external device 30 connected to the display device 10 based on a command from the control unit 100 and supplies the video data to the video selector unit 18. The audio data is supplied to the audio selector unit 26. Examples of the external device 30 include an HDD, an external memory, a BD player, a DVD player, and a CD player.

  The display device 10 includes a recording / reproducing unit 32 such as an optical disk drive. The recording / reproducing unit 32 is connected to the external input unit 31, and the display device 10 is recorded in the recording / reproducing unit 32 as in the case of reproducing the content data recorded in the external device 30. Content data can be played back.

  The separation unit 16 separates the stream data supplied from the digital tuner unit 14 or the IP broadcast tuner unit 23 into video data, audio data, and additional data. The video data, audio data, and additional data separated by the separation unit 16 are supplied to the video decoding unit 17, the audio decoding unit 25, and the EPG / OSD processing unit 24, respectively. The additional data separated by the separation unit 16 is also stored in the memory 7.

  The video decoding unit 17 decodes the video data separated by the separation unit 16. The video signal obtained by the video decoding unit 17 is DA-converted into an analog signal as necessary and supplied to the video selector unit 18.

  The audio decoding unit 25 decodes the audio data separated by the separation unit 16. The audio signal obtained by the audio decoding unit 25 is DA-converted into an analog signal as necessary and supplied to the audio selector unit 26.

  The EPG / OSD processing unit 24 generates a video signal representing a video to be displayed on the OSD (on-screen display) based on the additional data separated by the separation unit 16. Examples of the video displayed by OSD include EPG (electronic program guide) and subtitles. The video signal generated by the EPG / OSD processing unit 24 is supplied to the synthesis unit 20.

  In addition to the video signals from the analog tuner unit 12 and the video decoding unit 17 described above, the video selector unit 18 includes an external device 30 (for example, HDD, external memory, BD player, DVD) via the external input unit 31. A video signal output from a player or the like is supplied. Based on a command from the control unit 100, the video selector unit 18 selects a video signal to be reproduced from these video signals, and supplies the selected video signal to the video processing unit 19.

  The video processing unit 19 processes the video signal selected by the video selector unit 18. Examples of the processing here include IP conversion and frame rate conversion. The video signal processed by the video processing unit 19 is supplied to the synthesis unit 20. The synthesizing unit 20 synthesizes the video signal processed by the video processing unit 19 and the video signal generated by the EPG / OSD processing unit 24 and supplies them to the display control unit 21. The display control unit 21 drives the liquid crystal display device 22 based on the synthesized video signal.

  The liquid crystal display device 22 displays an image in the image quality priority mode (first mode) or the power saving mode (second mode). Here, the image quality priority mode refers to an operation mode in which the backlight of the liquid crystal display device 22 emits light with a standard amount of light, that is, an operation mode in which an image is displayed with standard luminance, and the power saving mode refers to the backlight of the liquid crystal display device 22. An operation mode in which the light is emitted with a light amount smaller than the standard light amount, that is, an operation mode in which an image is displayed with a luminance lower than the standard luminance. When the liquid crystal display device 22 includes a backlight capable of area control (local dimming), an operation mode for emitting light from the entire backlight, that is, an operation mode for displaying an image with a standard size is set as an image quality priority mode, An operation mode in which a part of the light is emitted, that is, an operation mode in which an image is displayed in a size smaller than the standard size may be set as the power saving mode. Further, the power saving mode may be realized by combining these and causing a part of the backlight to emit light with a light amount smaller than the standard light amount.

  In addition to the audio signals from the analog tuner unit 12 and the audio decoding unit 25 described above, the audio selector unit 26 includes an external device 30 (for example, HDD, external memory, BD player, DVD) via the external input unit 31. A sound signal output from a player, a CD player, or the like is supplied. The audio selector unit 26 selects an audio signal to be reproduced from these audio signals based on an instruction from the control unit 100, and supplies the selected audio signal to the audio output conversion unit 27.

  The audio output conversion unit 27 amplifies the audio signal selected by the audio selector unit 26 and supplies the amplified audio signal to the speaker 28. Here, the speaker 28 includes a right channel speaker unit, a left channel speaker unit, and a low frequency speaker unit (all not shown). For this reason, the audio output conversion unit 27 includes three amplifiers (not shown) corresponding to the three speakers. Specifically, a left channel amplifier, a right channel amplifier, and a low frequency amplifier are provided.

  The OPC (RGB) sensor 51 is a sensor that senses ambient illuminance. The OPC sensor 51 generates an electrical signal (hereinafter referred to as “illuminance signal”) that takes a value corresponding to the sensed ambient illuminance. The illuminance signal generated by the OPC sensor 51 is amplified by an amplifier circuit (not shown), converted to a digital signal by an ADC (not shown), and supplied to the control unit 100.

  The human sensor 52 is a sensor that detects whether or not a person is present in the vicinity. The human sensor 52 detects, for example, whether or not a person is present around by detecting movement of the heat source or detecting a difference between the temperature of the heat source and the ambient temperature. An output signal of the human sensor 52 (hereinafter referred to as “human sensor signal”) is amplified by an amplifier circuit (not shown), converted into a digital signal by an ADC (not shown), and supplied to the control unit 100. Is done.

  The human sensor 52 includes an active sensor that emits infrared rays and detects reflection thereof, and a passive sensor that does not emit infrared rays and detects infrared rays emitted from an object. The pyroelectric infrared sensor is an example of a passive sensor.

  When there is a person around the display device 10 (more precisely, the detection range of the human sensor 52), the movement of the person as a heat source is detected, and when there is no person around the display device 10, the heat source Human movement is not detected. For this reason, whether or not there is a person around the display device 10 can be determined by referring to the value of the human detection signal supplied from the human detection sensor 52.

  The power supply unit 53 operates in a normal mode or a standby mode. Here, the normal mode is an operation mode in which power is supplied to all blocks that consume power among the blocks (excluding the power supply unit 53) shown in FIG. When the power supply unit 53 is operating in the normal mode, the liquid crystal display device 22 displays an image in the image quality priority mode or the power saving mode described above. The standby mode refers to an external interface (external input unit 31, communication control unit 34, remote control light receiving unit 35), sensor (OPC sensor 51, human sensor 52) in the block (excluding the power supply unit 53) shown in FIG. This is an operation mode for supplying power only to the control unit 100.

  The control unit 100 switches the operation mode based on the remote control signal transmitted by the remote controller 36 and received by the remote control light receiving unit 35. For example, when a power button (not shown) provided on the remote controller 36 is pressed in the normal mode, the power supply unit 53 is switched to the standby mode, and the power button provided on the remote controller 36 is pressed in the standby mode. Then, the power supply unit 53 is switched to the normal mode. Further, the control unit 100 switches between the operation mode of the liquid crystal display device 22 and the operation mode of the power supply unit 53 based on the human detection signal supplied from the human detection sensor 52. Details of the control of the liquid crystal display device 22 based on the human presence signal will be described later with reference to another drawing.

(Configuration of control unit)
A configuration of the control unit 100 included in the display device 10 according to the present embodiment will be described with reference to FIG.

  As illustrated in FIG. 1, the control unit 100 includes a determination unit 101, a timer counter 102, a luminance adjustment unit 103, a volume adjustment unit 104, and a power supply control unit 105.

  The determination unit 101 determines whether or not there is a person around the display device 10 by comparing the value of the human detection signal acquired from the human detection sensor 52 with a threshold value recorded in advance in the memory 7. . Then, the determination unit 101 notifies the timer counter 102 of the determination result. As a method for determining whether or not there is a person around the display device 10 based on the value of the human signal, for example, when the human signal value acquired from the human sensor 52 is larger than a threshold, There is a determination method in which it is determined that there is a person and when the value of the human detection signal is smaller than the threshold value, it is determined that there is no person around.

  The timer counter 102 resets the timer value recorded in the memory 7 when the determination result notified from the determination unit 101 is switched from “there is no person” to “there is no person”. Each time the determination unit 101 notifies the determination result that “there is no person”, the timer counter 102 reads the timer value recorded in the memory 7, increments it by one, and records it in the memory 7. .

  Further, the timer counter 102 compares the timer value recorded in the memory 7 with a predetermined first threshold value, and notifies the luminance adjustment unit 103 and the volume adjustment unit 104 of the comparison result. For the notification of the comparison result, for example, a binary signal that takes the L level when the timer value is smaller than the first threshold and takes the H level when the timer value is equal to or greater than the first threshold is used. Can be used.

  The timer counter 102 compares the timer value recorded in the memory 7 with a predetermined second threshold value, and notifies the power control unit 105 of the comparison result. For the notification of the comparison result, for example, a binary signal that takes the L level when the timer value is smaller than the second threshold and takes the H level when the timer value is equal to the second threshold is used. Can be used. Here, the second threshold value is larger than the first threshold value.

  In the present embodiment, a configuration is employed in which the time when no person is present around the display device 10 is counted by incrementing the timer value recorded in the memory 7, but is recorded in the memory 7. You may employ | adopt the structure which counts the time when there is no person around the display apparatus 10 by decrementing the value of a timer. In this case, the second threshold value recorded in the memory 7 is a value smaller than the first threshold value.

  The luminance adjustment unit 103 switches the operation mode of the liquid crystal display device 22 based on the comparison result between the timer value and the first threshold value notified from the timer counter 102. Specifically, when a comparison result indicating that the timer value is equal to or greater than the first threshold is acquired, the luminance adjustment unit 103 sets the luminance of the video displayed on the liquid crystal display device 22 to a luminance lower than the standard luminance. When the comparison result that the timer value is smaller than the first threshold is acquired, the luminance of the video displayed on the liquid crystal display device 22 is set to the standard luminance. That is, when the timer value reaches the first threshold value, the operation mode of the liquid crystal display device 22 is switched from the image quality priority mode to the power saving mode.

  The volume adjustment unit 104 switches the operation mode of the audio output conversion unit 27 based on the comparison result notified from the timer counter 102 between the timer value and the first threshold value. Specifically, when the comparison result that the value of the timer is equal to or greater than the first threshold is acquired, the volume adjustment unit 104 indicates the amplification factor of the audio signal in the audio output conversion unit 27 and the display device 10 is in the normal mode. Switching to a lower amplification factor that is lower than the amplification factor (standard amplification factor) during operation, the volume output from the speaker 28 is lowered. When the comparison result that the timer value is smaller than the first threshold is acquired, the volume adjustment unit 104 switches the amplification factor of the audio signal to the standard amplification factor, and the volume output from the speaker 28 is set to the normal volume. To do. That is, when the timer value reaches the first threshold value, the power consumption is suppressed by switching the amplification factor in the audio output conversion unit 27 from the standard amplification factor to the low amplification factor.

  Further, when the comparison result that the timer value is equal to or greater than the first threshold is acquired, any of the right channel speaker unit, the left channel speaker unit, and the low frequency speaker unit provided in the speaker 28 The output may be stopped. That is, by stopping the power supplied to any of the left channel amplifier, the right channel amplifier, and the low frequency amplifier corresponding to each speaker unit, any of the speaker units included in the speaker 28 is stopped. Stop output. Thereby, power consumption in the audio output conversion unit 27 can be suppressed.

  The power supply control unit 105 controls the power supply unit 53 based on the comparison result between the timer value and the second threshold value notified from the timer counter 102. Specifically, when the timer value reaches the second threshold value, the operation mode of the display device 10 is switched from the normal mode to the standby mode by switching the operation mode of the power supply unit 53 from the normal mode to the standby mode. .

  Since the control unit 100 has the above-described configuration, the liquid crystal display device 22 can be switched to the power saving mode when there is no person around the display device 10 for a certain period of time, compared with the case where the liquid crystal display device 22 is not switched to the power saving mode. Thus, power consumption in the liquid crystal display device 22 can be reduced. In the power saving mode, since the video is continuously displayed on the liquid crystal display device 22, it is possible to reduce the power consumption while responding to the viewer's desire to view the video while being in a remote place.

  Note that after the timer value exceeds the second threshold, it is not necessary to consume power to display the video. Further, when viewing the video displayed on the display device 10 from a remote location, the viewer's demand for image quality is low. For this reason, while the human sensor does not detect the presence of the viewer, the viewer will not be dissatisfied even if the video is displayed in the power saving mode in which the power consumption required for displaying the video is small.

  In the present embodiment, when the volume adjustment unit 104 obtains a comparison result that the timer value is equal to or greater than the first threshold, the audio signal amplification factor in the audio output conversion unit 27 is decreased, and the speaker 28 Although a configuration has been shown in which power consumption is reduced by lowering the output volume, the present invention is not limited to this. For example, by stopping the power supply to any of the left channel amplifier, the right channel amplifier, and the low frequency amplifier among the speakers 28 provided on the left and right of the display device 10, the audio output is partially A configuration that stops automatically may be adopted. Moreover, you may employ | adopt the structure which reduces power consumption by combining these structures suitably.

  The first threshold value and the second threshold value are recorded in the memory 7 and are values that can be appropriately changed by the viewer.

  In addition, after operating the liquid crystal display device 22 in the power saving mode with low power consumption, the control unit 100 automatically stops the display of the video when there is no person around the display device 10 for a certain period of time. You may have the function to stop operation | movement of the apparatus 30. FIG. For example, when the external device 30 is an HDMI device, the control unit 100 can stop the operation of the external device 30 by transmitting a CEC command to the external device 30.

(Operation of control unit)
The operation of the control unit 100 provided in the display device 10 according to the present embodiment will be described with reference to FIGS. FIG. 3 is a flowchart showing the operation of the control unit 100 in the present embodiment. FIG. 4 is a state transition diagram of the display device 10 in the present embodiment.

  As shown in FIG. 3, when the display device 10 is switched from the standby mode to the normal mode, the timer counter 102 resets the timer value recorded in the memory 7 (sets it to an initial value) (step S1). . When the display device 10 is switched from the standby mode to the normal mode, the timer value is reset, and then the determination unit 101 determines whether there is a person around the display device 10 (step S2). When there is a person around display device 10 (when it is determined YES in step S2), the timer value is reset again (step S1). The operations in step S1 and step S2 are repeated until no people are present around display device 10 (until NO is determined in step S2) (corresponding to state T1 in FIG. 4). That is, the value of the timer is kept at the initial value until there is no person around display device 10 (until NO is determined in step S2).

  When there is no person around the display device 10 (when it is determined NO in step S2), the timer counter 102 reads the timer value recorded in the memory 7 and increments it by one and records it in the memory 7. (Step S3). The timer counter 102 reads the timer value recorded in the memory 7, increments it by one, records it in the memory 7, and then compares the incremented timer value with a predetermined first threshold value ( Step S4). When the value of the timer is smaller than the first threshold value (when NO is determined in step S4), the determination unit 101 determines again whether or not there is a person around the display device 10. In the operations from step S2 to step S4, it is determined that there is a person around the display device 10 (YES is determined in step S2), or it is determined that the timer value is equal to or greater than the first threshold ( It repeats until it determines with YES in step S4. The “normal mode” described above is an operation mode in which steps S1 to S4 are repeatedly executed.

  When the timer value is equal to or greater than the first threshold value (when it is determined YES in step S4), the luminance adjustment unit 103 switches the operation mode of the liquid crystal display device 22 from the image quality priority mode to the power saving mode (step S5). ). In the transition from the state T1 to the state T2 of the display device 10 illustrated in FIG. 4, since there are viewers around the display device 10, the liquid crystal display device 22 is operated in the image quality priority mode. This shows a state in which the operation mode of the liquid crystal display device 22 has been switched to the power saving mode because a certain time has passed since there were no viewers around. When the operation mode of the liquid crystal display device 22 is switched from the image quality priority mode to the power saving mode, the volume adjustment unit 104 switches the amplification factor of the volume in the audio output conversion unit 27 from the standard amplification factor to the low amplification factor. May be.

  When the operation mode of the liquid crystal display device 22 is switched from the image quality priority mode to the power saving mode, the determination unit 101 determines whether there is a person around the display device 10 (step S6). When there is no person around the display device 10 (when NO is determined in step S6), the timer counter 102 reads the timer value recorded in the memory 7 and increments it by one and records it in the memory 7. (Step S7). The timer counter 102 reads the timer value recorded in the memory 7, increments it by one and records it in the memory 7, and then compares the incremented timer value with a predetermined second threshold value ( Step S8). When the value of the timer is smaller than the second threshold value (when NO is determined in step S4), the determination unit 101 determines again whether or not there is a person around the display device 10. The operation from step S6 to step S8 is determined that there is a person around display device 10 (YES in step S6), or the timer value is determined to be equal to the second threshold value. (Corresponding to the state T2 in FIG. 4) until it is determined (YES in step S8).

  When there is a person around display device 10 (when it is determined YES in step S6), brightness adjusting unit 103 cancels the power saving mode and switches liquid crystal display device 22 from the power saving mode to the image quality priority mode (step S9). ). In the transition from the state T2 to the state T1 of the display device 10 shown in FIG. 4, the operation mode of the liquid crystal display device 22 has been switched to the power saving mode because a certain time has passed since the viewer is no longer around the display device 10. Thereafter, the viewer returns to the surroundings of the display device 10 before the state where there is no viewer around the display device 10 further passes, so that the operation mode of the liquid crystal display device 22 is switched to the normal image quality priority mode. It is shown that.

  When the value of the timer is equal to the second threshold value (when determined as YES in step S4), power supply control unit 105 switches the power supply to switch the operation mode of display device 10 from the normal mode to the standby mode. Notify the unit 53. In the transition from the state T2 to the state T3 of the display device 10 shown in FIG. 4, the operation mode of the liquid crystal display device 22 has been switched to the power saving mode because a certain time has passed since the viewer is no longer around the display device 10. Thereafter, since the state where there is no viewer around the display device 10 continues for a certain time, the display of the video is stopped.

  The human sensor 52 is unstable in operation for a while after the power supply is started. Therefore, the determination unit 101 determines that the person does not depend on the value of the human detection signal acquired from the human detection sensor 52 until a predetermined time elapses after the power supply to the human detection sensor 52 is started. You may employ | adopt the structure determined to exist.

  In the present embodiment, when the operation mode of the display device 10 is switched from the normal mode to the standby mode while the liquid crystal display device 22 is operating in the power saving mode, the standby mode is immediately switched to the present invention. Is not limited to this. That is, by gradually lowering the luminance of the liquid crystal display device 22 and gradually lowering the volume output from the speaker 28, the operation mode of the display device 10 is changed in a state where the liquid crystal display device 22 is operating in the power saving mode. The normal mode may be gradually switched to the standby mode.

  FIG. 3 shows a configuration in which the power supply unit 53 is switched to the standby mode when the period in which there is no person around the display device 10 exceeds the second threshold value that is larger than the first threshold value. The invention is not limited to this. That is, instead of switching the power supply unit 53 to the standby mode, a configuration in which it is switched to an OFF state (a state in which no power is supplied to any of the blocks shown in FIG. 2) or a configuration in which the backlight of the liquid crystal display device 22 is turned off is adopted. May be. In other words, when there are no people in the surroundings for a certain period of time, the power consumption required for video display is reduced. If it is the structure which stops a display, there exists an effect similar to the display apparatus 10 which concerns on this embodiment. This is because the power consumed in the backlight of the liquid crystal display device 22 occupies most of the power consumed in the display device 10.

(Program and recording medium)
The control unit 100 included in the display device 10 may be configured by hardware logic. Alternatively, it may be realized by software using a CPU (Central Processing Unit) as follows.

  That is, the control unit 100 includes a CPU such as an MPU that executes instructions of a program that realizes each function, a ROM (Read Only Memory) that stores the program, and a RAM (Random Access Memory) that expands the program into an executable format. ), And a storage device (recording medium) such as a memory for storing the program and various data.

  The object of the present invention is not limited to the case where the program is stored in the program memory of the control unit 100, but a record in which the program code (executable program, intermediate code program, or source program) of the program is recorded. This can also be achieved by supplying a medium to the display device 10 and reading and executing the program code recorded on the recording medium.

  The recording medium is not limited to a specific structure or type. That is, the recording medium includes, for example, a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. System, a card system such as an IC card (including a memory card) / optical card, or a semiconductor memory system such as a mask ROM / EPROM / EEPROM / flash ROM.

  Further, even if the control unit 100 (or the display device 10) is configured to be connectable to a communication network, the object of the present invention can be achieved. In this case, the program code is supplied to the control unit 100 via the communication network. The communication network is not limited to a specific type or form as long as it can supply the program code to the control unit 100. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication network, etc. may be used.

  The transmission medium constituting the communication network may be any medium that can transmit the program code, and is not limited to a specific configuration or type. For example, even with wired lines such as IEEE1394, USB, power line carrier, cable TV line, telephone line, ADSL (Asymmetric Digital Subscriber Line) line, infrared rays such as IrDA and remote control, Bluetooth (registered trademark), 802.11 wireless, HDR, mobile phone It can also be used by radio such as a telephone network, a satellite line, and a terrestrial digital network. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in the embodiments are also included. It is included in the technical scope of the present invention.

  The display device according to the present invention can be preferably applied to a television.

7 Memory 10 Display device (display device)
DESCRIPTION OF SYMBOLS 11 Antenna 12 Analog tuner part 13 Antenna 14 Digital tuner part 15 Digital demodulation part 16 Separation part (DMUX)
DESCRIPTION OF SYMBOLS 17 Video decoding part 18 Video selector part 19 Video processing part 20 Composition part 21 Display control part 22 Liquid crystal display device 23 IP broadcast tuner part 24 EPG / OSD processing part 25 Audio decoding part 26 Audio selector part 27 Audio | voice output conversion part 28 Speaker 30 External device (external device)
31 External Input Unit 32 Recording / Playback Unit 33 Tuning Unit 34 Communication Control Unit 35 Remote Control Light Receiving Unit 36 Remote Controller 51 OPC (RGB) Sensor 52 Human Sensor (Heat) Sensor (Human Sensor)
53 Power Supply Unit 100 Control Unit 101 Determination Unit 102 Timer Counter 103 Brightness Adjustment Unit (Switching Unit)
104 Volume adjuster (switching means)
105 Power control unit (stopping means)

Claims (11)

A display device that displays an image in a first mode or a second mode that consumes less power than the first mode to display an image,
A human sensor,
Mode switching means for switching the operation mode of the display device from the first mode to the second mode when the length of the dead period during which the presence of the viewer is not sensed by the human sensor exceeds a first threshold; ,
And a stop unit that automatically stops the display of the video when the dead period exceeds a second threshold value that is greater than the first threshold value.   The display device according to claim 1, wherein the brightness of the video displayed in the second mode is lower than the brightness of the video displayed in the first mode.   The display device according to claim 1 or 2, wherein a size of an image displayed in the second mode is smaller than a size of an image displayed in the first mode.   2. The apparatus according to claim 1, further comprising a volume reducing unit that reduces a volume of an audio output accompanying the video when a length of the dead period exceeds the first threshold value. 4. The display device according to any one of up to 3.   4. The apparatus according to claim 1, further comprising audio stop means for partially stopping output of audio accompanying the video when the length of the dead period exceeds the first threshold. The display device according to claim 1.   The said stop means stops the output of the audio | voice accompanying the said video, when the length of the said dead period exceeds the said 2nd threshold value, The any one of Claim 1-5 characterized by the above-mentioned. The display device described. The stop means automatically stops the operation of the external device when the length of the dead period exceeds the second threshold.
The display device according to claim 1, wherein the display device is a display device. The stop means is a viewer regardless of whether or not a viewer is detected by the human sensor until a predetermined time elapses after the power supply to the human sensor is started. Behaves as if exists,
The display device according to claim 1, wherein the display device is a display device. A stop method for stopping the display of video on a display device equipped with a human sensor,
A mode switching step of switching the operation mode of the display device from the first mode to the second mode when the length of the dead period during which the presence of the viewer is not sensed by the human sensor exceeds a first threshold; ,
And a stopping step of automatically stopping the display of the video when the dead period exceeds a second threshold value that is greater than the first threshold value.   A program for operating a computer included in the display device according to any one of claims 1 to 8, wherein the program causes the computer to function as each unit.   The computer-readable recording medium which recorded the program of Claim 10.

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