JP2011247935A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of efficiently controlling power supply to a display portion.SOLUTION: The display device comprises the display portion displaying an image, a person detecting portion detecting a person, an imaging portion imaging the person when the person detecting portion detects the person, a sight line determining portion determining a direction of a sight line of the person on the basis of the image of the person imaged by the imaging portion, and a power supply controlling portion controlling power supply to the display portion on the basis of the determination result by the sight line determining portion.

Description

  The present invention relates to a display device.

  2. Description of the Related Art Conventionally, there is a digital photo frame that detects that a viewer's face is facing a display unit based on an image captured by a camera (for example, see Patent Document 1). The digital photo frame controls power supply to the display unit based on the detection result.

JP 2009-141678 A

  However, in the above-described digital photo frame, when it is detected that the face of the viewer is facing the display unit, an image is displayed on the display unit even when the line of sight is not facing the display unit. The power supply to the display unit could not be performed efficiently.

  The objective of this invention is providing the display apparatus which can control the electric power supply with respect to a display part efficiently.

  The display device of the present invention includes a display unit that displays an image, a human detection unit that detects a person, an imaging unit that captures the person when the person is detected by the human detection unit, and an image that is captured by the imaging unit. A line-of-sight determination unit that determines the direction of the line of sight of the person based on the image of the person, and a power supply control unit that controls power supply to the display unit based on a determination result by the line-of-sight determination unit It is characterized by providing.

  The power supply control method for a display device according to the present invention includes a human detection step of detecting a human by a human detection unit, and an imaging step of imaging the human by an imaging unit when the human is detected by the human detection step. And a line-of-sight determination step for determining the direction of the line of sight of the person based on the image of the person imaged in the imaging step, and power supply to a display unit that displays the image based on the determination result of the line-of-sight determination step. And a control step for controlling.

  ADVANTAGE OF THE INVENTION According to this invention, the electric power supply with respect to a display part can be controlled efficiently.

It is a perspective view which shows the front surface of the digital photo frame which concerns on embodiment. 1 is a block diagram showing a system configuration of a digital photo frame according to an embodiment. FIG. It is a time chart explaining the display process of the digital photo frame which concerns on embodiment. It is a time chart explaining the display process of the digital photo frame which concerns on embodiment.

  Hereinafter, a digital photo frame (hereinafter referred to as a DPF) which is a display device according to an embodiment of the present invention will be described with reference to the drawings. In general, there are DPFs that are installed on a desk or the like, and those that are installed on a wall. However, in the embodiment of the present invention, the DPF is installed on a desk or the like ( A description will be given using an example of an electronic photo frame.

  FIG. 1 is a perspective view showing an appearance of a DPF according to an embodiment of the present invention. The DPF 2 includes a device main body 4 made of glass, plastic, or the like. On the front of the device main body 4, an LCD (Liquid Crystal Display) panel 6 on which information such as an image for viewing and time is displayed, and sound around the DPF 2 are displayed. Output from a microphone 8 that acquires the image, a pyroelectric sensor 9 that detects a person within a predetermined range in front of the DPF 2, a camera 10 that images the person, a speaker 12 that outputs music and audio, and a remote controller for operating the DPF 2 (not shown) An infrared detector 14 is provided for detecting the infrared rays. Here, the microphone 8 is both sides of the upper end of the front surface of the apparatus main body 4, the pyroelectric sensor 9 is the center of the upper end of the front face of the apparatus main body 4, the camera 10 is the right side of the upper center of the front end of the apparatus main body 4, and the speaker. 12 is disposed at both sides of the lower end of the front surface, and the infrared detecting unit 14 is disposed at the center of the lower end of the front surface.

  The pyroelectric sensor 9 includes an infrared sensor that detects infrared rays generated by a person and a Fresnel lens, and is a sensor that detects whether or not a person is present around the DPF 2. In response, the amplified detection signal is output to the CPU 30 (see FIG. 2). For example, the infrared ray emitted from the person located on the display surface side within a distance of about 1 m from the DPF 2 can be detected. Further, on the upper surface of the apparatus main body 4, a power switch 15 for switching the power on / off state of the DPF 2 and an operation key 16 used for setting the function of the DPF 2 and setting the display of the LCD panel 6 are provided. Further, on one side of the apparatus body 4, a memory card slot 18 into which a memory card storing data such as images and music is inserted, a USB port 20 to which a USB cable terminal and the like are connected, and Ethernet (registered trademark) ) A network terminal 22 to which a standard network cable is connected is provided.

  FIG. 2 is a block diagram illustrating a system configuration of the DPF 2 according to the embodiment. The CPU 30 for comprehensively controlling each part of the DPF 2 includes the above-described microphone 8, pyroelectric sensor 9, camera 10, infrared detector 14, power switch 15, operation key 16, memory card slot 18, USB port 20, and network terminal. 22 is connected. In addition, an internal memory 32 for storing data such as images and music, and a buffer memory 33 for temporarily storing image data generated from the imaging signal output from the camera 10 and audio data acquired by the microphone 8 are connected. Has been.

  Further, the CPU 30 includes a display control unit 34 that performs display control of images and information displayed on the LCD panel 6, a playback control unit 36 that performs playback control of music and audio output from the speaker 12, and a battery (power source). A power supply control unit 42 that controls power supply from 40 is connected. The LCD panel 6 includes a liquid crystal panel 6a and a drive circuit that drives the liquid crystal panel 6a, and displays an image corresponding to the image signal supplied from the display control unit 34. It should be noted that the CPU 30 can make a determination of a person's line of sight, which will be described later, at a predetermined frequency or a predetermined period (a constant time interval) based on a measurement value of a timer (not shown) according to a program stored in the internal memory 32 or the like. it can.

  In the liquid crystal panel 6a constituting the LCD panel 6, color filters colored in R (red), G (green), and B (blue) are arranged corresponding to the pixels of the screen. A voltage corresponding to the luminance values of the R, G, and B hue components of each pixel included in the video signal is applied to the liquid crystal corresponding to R, G, and B of each pixel of the liquid crystal panel 6a. Thereby, the alignment of the liquid crystal molecules is controlled, and the transmittance of the irradiation light to the liquid crystal is adjusted. A backlight unit 6b configured to include an LED (Light Emitting Diode) as a light source is a backlight that irradiates the liquid crystal panel 6a of the LCD panel 6 from its back surface. Here, the backlight unit 6b emits light with luminance corresponding to the magnitude of the current supplied from the backlight driving unit 6c. The backlight drive unit 6 c adjusts execution and stop of power supply from the battery 40 to the backlight LED in accordance with an instruction from the CPU 30. Further, the backlight driving unit 6 c adjusts the magnitude of the current supplied from the battery 40 to the backlight LED in accordance with an instruction from the CPU 30.

  Next, display processing of the DPF 2 according to the embodiment of the present invention will be described with reference to the time chart shown in FIG. In the embodiment of the present invention, a slide show display using still image data read from the internal memory 32 is performed on the LCD panel 6 of the DPF 2 when the line of sight of the person faces the direction of the LCD panel 6. Assumed to be performed. When the operator operates the power switch 15 to turn on the power of the DPF 2, the CPU 30 causes the pyroelectric sensor 9 to start detecting people within a predetermined range in front of the DPF 2 (pyroelectric sensor ON). The CPU 30 determines whether or not a person is detected based on the output from the pyroelectric sensor 9, and the CPU 30 causes the camera 10 to start imaging a person within a predetermined range in front of the DPF 2 when a person is detected. (Camera ON). Here, for example, the camera 10 captures images and outputs image data at 2 frames per second. Further, the CPU 30 determines the direction of the line of sight of the person included in the image data based on the image data output from the camera 10 at 2 frames per second. Specifically, the CPU 30 determines whether the human face is facing the LCD panel 6 based on the contour shape of the human face in the image data output from the camera 10 and temporarily stored in the buffer memory 33. When the direction of the person's face is detected to face the LCD panel 6, the direction of the person's line of sight is determined based on the area of the person's eyes and the position of the pupil in the image data. 6 is determined. Here, the CPU 30 determines that the direction of the person's line of sight is the LCD panel 6 when the image data in which the direction of the person's line of sight faces the LCD panel 6 continues for a predetermined number of frames (for example, 7 frames). It is determined that it is suitable. The determination by the CPU 30 is continuously performed at a predetermined frequency (for example, twice per second) until it is determined that the direction of the person's line of sight is facing the LCD panel 6.

  When the CPU 30 determines that the direction of the line of sight of the person is facing the LCD panel 6, the CPU 30 informs the power supply control unit 42 via the backlight driving unit 6 c of the LCD panel 6 so that the LCD panel 6 has a predetermined luminance. The power supply to the backlight unit 6b is controlled, and the display control unit 34 is instructed to display an image on the LCD panel 6. In other words, a slide show is displayed at a predetermined brightness on the LCD panel 6 using the image data stored in the internal memory 32 (image display ON). When the LCD panel 6 starts displaying an image, the CPU 30 switches the imaging by the camera 10 to imaging at a fixed time interval, and switches the determination of the direction of the person's line of sight to periodic (fixed time interval) determination. Note that the imaging performed in this case may be imaging performed at a frequency lower than 2 frames per second. For example, the CPU 30 captures images twice every 5 seconds by the camera 10 for a predetermined time, and captures 10 frames within the predetermined time. Then, when the image data of 10 frames continuously includes image data having a predetermined number of frames (for example, 5 frames) or more and a person's line of sight facing the LCD panel 6 in the 10 frames of image data. Then, it is determined that the direction of the line of sight of the person is facing the LCD panel 6. Here, if the CPU 30 determines that the direction of the line of sight of the person is facing the LCD panel 6, the CPU 30 controls to continue displaying images on the LCD panel 6. On the other hand, when determining that the direction of the line of sight of the person is not facing the LCD panel 6, the CPU 30 controls the power supply control unit 42 to stop the power supply related to the display on the LCD panel 6 and turns off the LCD panel 6. Let

  In addition, when the LCD panel 6 is turned off, the CPU 30 switches the imaging by the camera 10 to continuous imaging, and continuously determines the direction of the human line of sight at a predetermined frequency as described above. Note that the determination of the direction of the line of sight by the CPU 30 is continuously performed during the imaging period of the camera 10.

  When no person is detected by the pyroelectric sensor 9, the power supply control unit 42 stops the power supply to the camera 10, and the CPU 30 stops determining the direction of the person's line of sight. Even in this case, power supply to the pyroelectric sensor 9 by the power supply control unit 42 is continued, and the pyroelectric sensor 9 detects a person. When the operator operates the power switch 15 to turn off the DPF 2, the detection by the pyroelectric sensor 9 is stopped.

  According to the display device according to the embodiment of the present invention, the power supply to the display unit can be controlled based on the direction of the line of sight of a person within a predetermined range in front of the display apparatus. When is facing the display unit, an image can be displayed on the display unit. Therefore, it is possible to efficiently control power supply to the display unit. In addition, when there is no person within the predetermined range in front of the display device, the camera is not used for determining the direction of the line of sight of the person, so the memory is wasted due to the image data output from the camera. Consumption can be prevented. In addition, when there is no person within a predetermined range in front of the display device, the person is detected by the pyroelectric sensor and no image is taken by the camera, so the power consumption of the pyroelectric sensor is smaller than the power consumption of the camera. Efficiency is good.

  In the above-described embodiment, when the image is displayed on the LCD panel 6 and the CPU 30 determines that the direction of the line of sight of the person is not facing the LCD panel 6, the backlight unit of the LCD panel 6. Although the power supply to 6b is stopped and the LCD panel 6 is turned off, the power supply control unit 42 controls the power supply to the backlight unit 6b to lower the brightness of the LCD panel 6 below a predetermined brightness during normal display. You may do it. In this case, if the CPU 30 determines that the direction of the person's line of sight is facing the LCD panel 6, the power supply control unit 42 controls the power supply to the backlight unit 6 b and the luminance displayed on the LCD panel 6. Is returned to a predetermined luminance. When no person is detected by the pyroelectric sensor 9, the power supply control unit 42 stops the power supply to the backlight unit 6b among the power supply related to the display on the LCD panel 6, and turns off the LCD panel 6. You may do it.

  Further, in the above-described embodiment, when a person is detected by the pyroelectric sensor 9 and imaging by the camera 10 is started, detection by the pyroelectric sensor 9 is stopped, and based on image data output from the camera 10. The size of the person's face is detected, and based on the detected size of the face, it is determined whether or not there is a person within a predetermined range in front of the LCD panel 6, and it is determined that there is no person within the predetermined range. In such a case, the power supply control unit 42 may stop the power supply to the backlight unit 6b and turn off the LCD panel 6.

  In the above-described embodiment, when the person is detected by the pyroelectric sensor 9 and when the LCD panel 6 is turned off, the CPU 30 continuously determines the direction of the line of sight at a predetermined frequency. You may carry out with a predetermined period (fixed time interval). In this case, as shown in FIG. 4, when a person is detected by the pyroelectric sensor 9, the CPU 30 determines the direction of the person's line of sight periodically (constant time interval) performed in the above-described embodiment. Similarly to the above, imaging is performed twice every 5 seconds by the camera 10 for a predetermined time, and 10 frames are captured within the predetermined time (camera ON). If the CPU 30 determines the direction of the person's line of sight based on the 10 frames of image data and determines that the direction of the person's line of sight is facing the LCD panel 6, the power supply control unit 42 causes the backlight unit to The power supply to 6b is controlled to display an image of the image data stored in the internal memory 32 on the LCD panel 6 with a predetermined luminance (image display ON). Further, when an image is displayed on the LCD panel 6, if it is determined that the direction of the person's line of sight is not facing the LCD panel 6, the power supply control unit 42 stops the power supply to the backlight unit 6 b and stops the LCD panel. 6 is turned off. Even in this case, while the person is detected by the pyroelectric sensor 9, imaging by the camera 10 is performed at predetermined time intervals, and the determination of the direction of the person's line of sight is performed periodically (fixed time intervals).

  In the above-described embodiment, the pyroelectric sensor 9 is used to detect a person within a predetermined range in front of the DPF 2, but a microphone 8 may be used. In this case, if the sound around the DPF 2 acquired by the microphone 8 is equal to or higher than a predetermined level, the CPU 30 determines that there is a person within a predetermined range in front of the DPF 2.

  In the above-described embodiment, the power supply to the backlight unit 6b of the LCD panel 6 is controlled when a slide show is displayed on the LCD panel 6, but the backlight of the LCD panel 6 is displayed when displaying a moving image. You may make it control the electric power supply with respect to the part 6b.

  In the above-described embodiment, the power supply to the backlight unit 6b of the LCD panel 6 is controlled. However, the present invention is not limited to the control of the power supply to the backlight unit 6b. You may make it control the electric power supply with respect to EL (Electro Luminescence) display. Further, the display luminance of the display elements of the LCD panel, plasma display panel, and organic EL display may be controlled, and the ON / OFF of the power supply may be controlled.

  Further, in the above-described embodiment, instead of the battery 40, power may be supplied to the backlight unit 6b via the backlight drive unit 6c of the LCD panel 6 using a commercial power source as a power source.

  DESCRIPTION OF SYMBOLS 6 ... LCD panel, 6a ... Liquid crystal panel, 6b ... Backlight part, 6c ... Backlight drive part, 8 ... Microphone, 9 ... Pyroelectric sensor, 10 ... Camera, 30 ... CPU, 42 ... Power supply control part.

Claims (8)

A display for displaying an image;
A human detection unit for detecting a person;
An imaging unit that images the person when the person is detected by the person detection unit;
A line-of-sight determination unit that determines the direction of the line of sight of the person based on the image of the person imaged by the imaging unit;
A display device comprising: a power supply control unit that controls power supply to the display unit based on a determination result by the line-of-sight determination unit. The line-of-sight determination unit determines whether the direction of the line of sight faces the display unit,
The power supply control unit performs power supply so that the luminance of the display unit is lower than the predetermined luminance when the line-of-sight determination unit determines that the direction of the line of sight does not face the display unit. The display device according to claim 1, characterized in that: The line-of-sight determination unit determines whether the direction of the line of sight faces the display unit,
The power supply control unit supplies power to display the image with a predetermined luminance on the display unit when the line-of-sight determination unit determines that the direction of the line of sight faces the display unit. The display device according to claim 1, wherein:   The said power supply control part stops at least one part among the power supply relevant to the display in the display part which displays the said image, when the said person is not detected by the said person detection part, The said power supply control part is characterized by the above-mentioned. 4. The display device according to any one of 3.   The line-of-sight determination unit determines the direction of the line of sight at a first frequency when the person is detected by the human detection unit, and determines that the direction of the line of sight faces the display unit The display device according to claim 1, wherein the direction of the line of sight is determined at a second frequency smaller than the first frequency.   The display according to any one of claims 1 to 4, wherein when the person is detected by the person detection unit, the line-of-sight determination unit periodically determines the direction of the line of sight. apparatus.   The display device according to claim 1, wherein the human detection unit includes a pyroelectric sensor or a microphone. A person detecting step of detecting a person by the person detecting unit;
When the person is detected by the person detection step, an imaging step of imaging the person by an imaging unit;
A line-of-sight determination step of determining a direction of the line of sight of the person based on the image of the person imaged in the imaging step;
And a control step of controlling power supply to a display unit that displays an image based on a determination result in the line-of-sight determination step.

Images