JP2007158787A - Display unit and display control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display unit for controlling the size of an input image signal according to the viewing and listening distance for holding always an angle of field adequately. <P>SOLUTION: A display device 10 includes a display panel 22 for displaying an input image signal; a viewing and listening distance calculation unit 23 for calculating a viewing and listening distance between the display unit 10 and a viewer; and a resizer 16 for resizing the input image signal according to the calculated viewing and listening distance, and the resized input image signal is displayed on a display panel 22. The display device 10 includes a light source for illuminating the display panel 22, and the lighting/extinction of the light source is so controlled that only a region for displaying the input image signal, which are resized by the resizer 16, is illuminated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device and a display control method, and more particularly to a display device and a display control method capable of controlling the size of an input image signal in accordance with a viewing distance so as to always maintain an appropriate viewing angle.

  Television receivers (TVs) having a large screen are spreading to ordinary households. Recently, a house with a large living room is not uncommon, but there are more opportunities to watch large-screen TVs in a smaller living space than in the West. Under such a viewing environment, the viewer is tired because the screen is too large for viewing nearby. In particular, in the case of a child or the like, there is a problem in that near-sightedness tends to occur when the TV screen is viewed nearby. This is due to the fact that the optimum viewing angle is exceeded.

  In order to improve the above state, it is necessary to maintain an appropriate viewing distance between the viewer and the TV according to the size of the display screen of the TV. For example, in conventional TVs, the optimal viewing distance is about five times the height of the screen, and in high-definition LCD TVs and plasma TVs such as plasma TVs, high-quality images have advanced. The optimum viewing distance is about three times the height.

  In the case of the above-mentioned thin TV, for example, when the screen size is 50 inches, the height of the screen is about 60 cm, so the optimum viewing distance is calculated as 60 cm × 3 = 180 cm. Similarly, when the screen size is 42 inches When the optimum viewing distance is about 160 cm and the screen size is 32 inches, the optimum viewing distance can be obtained as about 115 cm.

In general, the human visual field is classified into several classes according to the visual recognition level. The list is as follows in order of narrow viewing angle.
(1) Discriminating field of view: Highly accurate information acceptance range as when reading characters (up and down, left and right within about 5 degrees)
(2) Effective field of view: The range in which information can be searched only by eye movement (up and down about 10 degrees, left and right within about 15 degrees)
(3) Guidance field of view: Range that affects human sense of direction to the extent that the presence of information is barely understood (within about 40 degrees vertically and within about 50 degrees left and right)

  In the above, since the range in which the human is gazing at the image is at most within the range of the effective visual field in which information can be received by eye movement, in order to reduce fatigue when watching TV, It is said that about 15 degrees to the left and right is good centering on the viewer who is located. This viewing angle range can be realized by maintaining the optimum viewing distance for each screen size as described above.

  As described above, it is an effective method for reducing fatigue and preventing a decrease in visual acuity that the viewer himself / herself keeps the viewing distance with respect to the TV properly when watching the TV. In many cases, the viewing distance is inadvertent and the appropriate viewing distance is not maintained. Therefore, instead of moving the viewing position of the viewer in order to obtain the optimum viewing distance, the image size to be displayed on the screen is changed (resized), whereby the distance between the viewer and the TV is set to the optimum viewing distance (that is, the optimum visual field). The method of making it a corner) can be considered.

Here, Patent Literature 1 and Patent Literature 2 disclose a liquid crystal display device having a function of changing an image size to be displayed on a screen. In these, only a predetermined backlight light source is turned on to illuminate only a predetermined range on the screen, and a resized image is displayed in this range.
Japanese Patent Laid-Open No. 10-232653 JP 2001-21863 A

  However, the inventions described in Patent Document 1 and Patent Document 2 are mainly intended to reduce power consumption of portable devices, and are not associated with image size and viewing distance. Therefore, even if the inventions described in Patent Document 1 and Patent Document 2 are applied to a large screen TV, the image size cannot be controlled in accordance with the viewing distance, so that the viewing angle cannot be maintained properly.

  The present invention has been made in view of the above circumstances, and provides a display device and a display control method capable of controlling the size of an input image signal according to a viewing distance so as to always maintain an appropriate viewing angle. , With purpose.

  In order to solve the above problems, a first technical means of the present invention is a viewing distance calculating means for calculating a viewing distance between the display device and a viewer in a display device having a display panel for displaying an input image signal. And a resizing means for resizing the size of the input image signal in accordance with the calculated viewing distance, and displaying the resized input image signal on the display panel.

  The second technical means includes storage means that stores the viewing distance between the display device and the viewer and the size information of the input image signal in association with the first technical means, and the resizing means includes the storage means. The size information of the input image signal corresponding to the viewing distance calculated by the viewing distance calculation unit is acquired by referring to the means, and the input image signal is resized based on the size information. is there.

  The third technical means includes a light source that illuminates the display panel in the first or second technical means, and the light source illuminates only a region for displaying the input image signal resized by the resizing means. It is characterized in that lighting / extinguishing is controlled.

  According to a fourth technical means, in the third technical means, the light source is any one of a light emitting diode (LED), a cold cathode tube, a combination of an LED and a cold cathode tube.

  According to a fifth technical means, in the first technical means, the viewing distance calculating means is a distance sensor capable of measuring a distance between two points using infrared rays, and transmits the infrared rays toward the viewer. And a plurality of receiving units that receive reflected light from the viewer of the transmitted infrared rays.

  A sixth technical means is the first technical means, wherein the viewing distance calculating means is a distance sensor capable of measuring a distance between two points using an ultrasonic wave or a sound wave. And a receiving unit that receives the transmitted ultrasonic wave or a reflected wave of the sound wave from the viewer.

  The seventh technical means displays a message for prompting the user to leave the display device when the viewing distance calculated by the viewing distance calculating means is smaller than a predetermined distance in the first technical means. It is characterized by doing.

  The eighth technical means includes the OSD means for superimposing an on-screen signal on the input image signal in any one of the first to seventh technical means, wherein the OSD means is the input image resized by the resizing means. The frame information is superimposed on the periphery of the area where the signal is displayed.

  A ninth technical means is the eighth technical means, wherein the OSD means superimposes a predetermined color signal as the frame information.

  A tenth technical means comprises any one of the first to ninth technical means, comprising a remote operation device for remotely operating the display device, wherein the viewing distance calculation means is a predetermined distance from the remote operation device. When an operation signal is received, a viewing distance between the display device and the viewer is calculated.

  In an eleventh technical means, in a display control method using a display device having a display panel for displaying an input image signal, a step of calculating a viewing distance between the display device and a viewer, and according to the calculated viewing distance The method includes a step of resizing the input image signal and a step of displaying the resized input image signal on the display panel.

According to the present invention, since the size of the input image signal can be controlled according to the viewing distance so as to always maintain an appropriate viewing angle, an optimum viewing angle can be secured even when viewing a large screen TV at a short distance. As a result, the scanning line is inconspicuous, or the frequency of moving the eyes and neck is drastically reduced, which is effective for reducing the viewer's fatigue and preventing a reduction in visual acuity.
In addition, when viewing a large screen TV at a short distance, the lighting location of the backlight can be controlled according to the display range of the resized image, so that power consumption can be reduced.
Further, by not turning on the backlight other than the display range of the resized image, the periphery of the display range becomes almost black, and stray light can be reduced and eye fatigue can be reduced.

  The display device according to the present invention can control the size of an input image signal according to the viewing distance so as to always maintain an appropriate viewing angle, and can be a liquid crystal display (LCD), a plasma display, an organic EL display, an electrophoretic display, an electric field, It can be applied to all thin display devices such as an emission display (FED), and is particularly suitable for a display device having a large screen of 40 inches or more. DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a display device of the invention will be described with reference to the accompanying drawings.

  FIG. 1 is a block diagram illustrating a configuration example of a display device according to an embodiment of the present invention. In the figure, reference numeral 10 denotes a display device, which includes a YC separation unit 11, a selector 12, an AD converter (ADC). ) 13, selector 14, IP conversion unit 15, resizer 16, image quality adjustment unit 17, scaler 18, γ correction unit 19, OSD (on-screen display) unit 20, timing controller (T-CON) 21, display panel 22 , A viewing distance calculation unit 23, a memory 24, and a control unit 25. The above units are connected to a control unit 25, which is a microcomputer, via a system bus, and operations are controlled by the control unit 25. The memory 24 stores a control program, data, and the like for controlling the operation of the display device 10.

  The display device 10 can receive an analog signal such as a composite (CVBS) signal, a separate (YC) signal, a component (YPbPr) signal, and an RGB signal from a plurality of video sources, a digital signal conforming to the ITU-R656 standard, DVI ( It is possible to input an image signal such as a digital RGB signal conforming to the Digital Visual Interface) standard.

  In FIG. 1, when a composite signal which is an analog signal is input, the YC separation unit 11 separates the composite signal into a Y (luminance) signal and a C (chroma) signal, and outputs them to the selector 12. In addition, other analog signals such as a separate signal, a component signal, and an RGB signal are input to the selector 12. The selector 12 switches a plurality of analog image signals (composite signal, separate signal, component signal, RGB signal) and outputs them to the ADC 13. The ADC 13 converts the analog signal from the selector 12 into a digital signal and outputs it to the selector 14.

  The selector 14 switches the digital signal from the ADC 13 or the ITU-R656 standard digital signal and outputs it to the IP converter 15. The IP conversion unit 15 performs IP conversion for converting the digital signal from the selector 14 from interlace to progressive, and outputs the digital signal after the IP conversion to the resizer 16.

  The resizer 16 is a resizing means for resizing (enlarging or reducing) the size of the input image signal, and receives a digital signal from the IP conversion unit 15 or a digital RGB signal of the DVI standard. The viewing distance calculation unit 23 is a means for calculating the viewing distance between the display device 10 and the viewer, and various distance sensors shown in FIG. The viewing distance information calculated by the viewing distance calculation unit 23 is input to the resizer 16, and the resizer 16 resizes the horizontal and vertical sizes of the input image signal based on the viewing distance information from the viewing distance calculation unit 23.

The resizing method by the resizer 16 will be specifically described. For example, as described above, when the display device 10 is a thin TV such as a high-definition liquid crystal TV and the optimal viewing distance is three times the height of the screen, the viewing distance calculated by the viewing distance calculation unit 23 One third of the image height may be set to the height of the screen (that is, the vertical size of the input image signal). If the vertical size of the input image signal is obtained, the horizontal size is obtained based on the aspect ratio of the input image signal. The resizer 16 calculates the horizontal and vertical sizes of the input image signal, that is,
Vertical size = viewing distance / 3, horizontal size = vertical size × aspect ratio (1)
The resizing process is performed based on the obtained size of the input image signal.

  As another embodiment, the viewing distance between the display device 10 and the viewer and the size information of the input image signal may be associated with each other and stored in advance in the memory 24 as table information. In this case, the resizer 16 acquires the size information of the input image signal corresponding to the viewing distance calculated by the viewing distance calculation unit 23 by referring to the memory 24, and resizes the input image signal based on the size information. I do.

  The image signal resized by the resizer 16 (hereinafter often referred to as a resized image signal) is output to the image quality adjustment unit 17. The resized image signal is subjected to image quality enhancement correction processing in the image quality adjustment unit 17, processing such as aspect ratio conversion is performed (if necessary) in the scaler 18, and γ correction processing is performed in the γ correction unit 19. Is given. The resized image signal that has undergone a series of image processing is input to the OSD unit 20 and an on-screen signal is superimposed thereon.

  The timing controller 21 is a means for controlling the display on the display panel 22 and outputs timing pulses necessary for driving and displaying the panel to control a gate driver and a source driver (not shown) included in the display panel 22.

  The backlight light source (not shown) of the display panel 22 is, for example, a cold cathode tube (straight tube, U-tube, etc.), a light emitting diode (LED), or a hybrid of a cold cathode tube and LED. May be. The backlight may be arranged either directly below the display panel 22 or side edge arranged on the side of the display panel 22, but the backlight may be arranged according to the display area of the resized image signal. When controlling the turning on / off of the light source, it is desirable to use a direct type.

  The resized image signal by the resizer 16 is displayed in a partial area of the screen of the display panel 22 as shown in FIG. 2B, which will be described later, and the part other than the display area of the resized image signal is muted black. At this time, a pseudo frame (frame) may be provided by the OSD unit 20 around the display area of the resized image signal. As this pseudo frame, for example, gray display, shaded display, or the like is performed.

  In this way, by controlling the size of the input image signal according to the viewing distance, it is possible to ensure an optimal viewing angle even when viewing a large screen TV at a short distance. Further, by adding frame information around the display area, it is possible to give the viewer the impression of watching a TV with a small screen size, and the viewer can view without feeling uncomfortable.

  FIG. 2 is a diagram showing how the size of the input image signal changes depending on the viewing distance. In the figure, reference numeral 22a denotes a display area in which the input image signal is displayed. In this example, a case will be described in which the display device 10 is a thin TV such as a high-definition liquid crystal TV and the optimum viewing distance is three times the screen height.

  As shown in FIG. 2A, when the viewer V is viewing from the position of the viewing distance L from the display panel 22 of the display device 10, the height of the display region 22a is controlled to be L / 3. The In addition, the height (L / 3) of the display area 22a in this example corresponds to the height of the screen of the display panel 22 and shows a state where a full screen is displayed. Here, when the viewer V moves to a place farther than the viewing distance L, the size of the display area 22a cannot be increased any more, and thus the full screen is displayed regardless of the viewing distance.

  In addition, as shown in FIG. 2B, when the viewer V is viewing from the position of the viewing distance L ′ (<viewing distance L) from the display panel 22 of the display device 10, the height of the display area 22a is high. It is controlled to be L ′ / 3. In this case, from the relationship of viewing distance L ′ <viewing distance L, the height L ′ / 3 <L / 3 of the display area 22a is obtained, and the display area 22a shown in FIG. Since the display area 22a shown in FIG. 2B is smaller than the screen size of the display panel 22, the surrounding area other than the display area 22a is displayed with black mute. At this time, a frame display such as a gray display or a shaded display may be provided around the display area 22a. Here, the position where the display area 22a is displayed is set at the approximate center of the screen of the display panel 22. However, the display area 22a may be other than the approximate center of the screen, and can be arbitrarily set.

  As another embodiment of the resizing method according to the viewing distance, a range may be set for the viewing distance, and the size of the display area 22a may be controlled stepwise according to the range. A case where the screen size of the display panel 22 is 50 inches will be described as an example. As described above, when the screen size is 50 inches, the height of the screen is about 60 cm, so the optimum viewing distance is 60 cm × 3 = 180 cm. When the screen size is 42 inches, the optimum viewing distance is about 160 cm, When the screen size is 32 inches, the optimum viewing distance is about 115 cm.

  Based on the optimum viewing distance, when the viewing distance of the viewer V is 180 cm or more, the display area 22a is a full screen display of 50 inches, and when the viewing distance is 160 cm or more and less than 180 cm, the display area 22a is a screen of 42 inches. When the viewing distance is 115 cm or more and less than 160 cm, the display area 22a is displayed as a 32-inch screen, and when the viewing distance is less than 115 cm, the display area 22a is left as a 32-inch screen display or one size. Control to display a small screen.

  The association between the range of the viewing distance and the size of the display area 22a can be arbitrarily set within a range in which an appropriate viewing angle can be maintained, but the lighting / extinguishing of the backlight is controlled according to the display area 22a. It is desirable to determine the size of the display area 22a in consideration of the arrangement of the backlight.

  If the viewer knows the relationship between viewing distance and screen size, or if the viewer can grasp the guide information, the viewer changes the screen size based on the current viewing distance. You may make it do. By enabling such manual setting, it is possible to respond to a case where a user wants to feel a sense of reality or immersion by viewing on a larger screen even at a slight sacrifice in viewing angle.

  FIG. 3 is a diagram illustrating an example of a message displayed when the viewing distance is smaller than the predetermined distance. As a result of the viewer V attempting to view the display panel 22 close to the viewing panel 22, the viewing distance may become smaller than a predetermined distance (minimum viewing distance). That is, when the viewer V tries to view the display panel 22 close to the viewing distance corresponding to the resized image signal of the minimum size that can be displayed on the display device 10, as shown in FIG. A message for prompting the user to leave the apparatus 10 (display panel 22) may be displayed on the screen.

  On the basis of FIG. 4 to FIG. 6, a configuration for controlling turning on / off of the backlight light source so that only the display area 22 a for displaying the input image signal resized by the resizer 16 is illuminated on the screen of the display panel 22. explain.

  FIG. 4 is a diagram illustrating a configuration example of the display panel 22 in the case where LEDs are used as the backlight light source. In the figure, reference numerals 26a to 26i denote LEDs. In this example, the nine LEDs 26a to 26i are arranged directly below the display panel 22, and the lighting / extinguishing of the LEDs 26a to 26i is controlled according to the size of the display area 22a. That is, only the LED 26e corresponding to the display area 22a is turned on, and the display area 22a is illuminated by the LED 26e. On the other hand, the LEDs 26a, 26b, 26c, 26d, 26f, 26g, 26h, and 26i (other than the LED 26e) corresponding to portions other than the display area 22a (hatched portions in the figure) are turned off. This control of turning on / off the backlight light source is executed by the control unit 25 based on information on the display area 22 a obtained from the resizer 16.

  In this way, the power consumption can be reduced by lighting the LED only at the portion corresponding to the display area 22a. Further, when the LEDs other than the display area 22a are turned off, the periphery of the display area 22a becomes nearly black, so that stray light can be reduced and eye fatigue can be reduced.

  FIG. 5 is a diagram showing a configuration example of the display panel 22 in the case where a cold cathode tube is used as a backlight light source. In the figure, reference numerals 26a to 26c denote straight tube type cold cathode tubes. In this example, the three cold cathode fluorescent lamps 26a to 26c are arranged immediately below the display panel 22, and lighting / extinguishing of the cold cathode fluorescent lamps 26a to 26c is controlled according to the size of the display area 22a. That is, only the cold cathode tube 26b corresponding to the display region 22a is turned on, and the display region 22a is illuminated by the cold cathode tube 26b. On the other hand, the cold-cathode tubes 26a and 26c (other than the cold-cathode tube 26b) corresponding to portions other than the display region 22a (hatched portions in the figure) are turned off. This control of turning on / off the backlight light source is executed by the control unit 25 based on information on the display area 22 a obtained from the resizer 16.

  Since the cold cathode tubes 26a to 26c shown in this example are straight tube types, when the display region 22a is illuminated by the cold cathode tube 26b, the left and right portions of the display region 22a are also illuminated by the cold cathode tube 26b. It becomes the state.

  FIG. 6 is a diagram showing another configuration example of the display panel 22 in the case where a cold cathode tube is used as a backlight light source. In the figure, reference numerals 26a to 26d denote U-shaped cold cathode tubes. In this example, the four cold cathode fluorescent lamps 26a to 26d are arranged immediately below the display panel 22, and lighting / extinguishing of the cold cathode fluorescent lamps 26a to 26d is controlled according to the size of the display area 22a. That is, only the cold cathode tube 26b corresponding to the display region 22a is turned on, and the display region 22a is illuminated by the cold cathode tube 26b. On the other hand, the cold-cathode tubes 26a, 26c, and 26d (other than the cold-cathode tube 26b) corresponding to portions other than the display region 22a (hatched portions in the figure) are turned off. This control of turning on / off the backlight light source is executed by the control unit 25 based on information on the display area 22 a obtained from the resizer 16.

  In this way, the power consumption can be reduced by turning on the cold cathode fluorescent lamp only at the portion corresponding to the display region 22a. Further, when the cold cathode tubes other than the display area 22a are turned off, the periphery of the display area 22a becomes almost black, and stray light can be reduced and eye fatigue can be reduced.

  The display panel 22 may have a configuration other than the examples shown in FIGS. 4 to 6. For example, the backlight source may be a hybrid type in which an LED and a cold cathode tube are combined.

  FIG. 7 is a diagram illustrating a configuration example of the viewing distance calculation unit 23. The viewing distance calculation unit 23 is an infrared distance sensor that can measure the distance between two points using infrared rays, and includes a transmission unit 23 a that transmits infrared rays to the viewer V, and the transmitted viewer V of infrared rays. And a plurality of receiving units 23b that receive the reflected light from. FIG. 7A is a view of the display panel 22 as viewed from the side, and FIG. 7B is a view of the display panel 22 as viewed from the front. Here, an example in which four receiving units 23b are provided is shown, but the number of receiving units 23b is arbitrary, and the position where the receiving units 23b are arranged can be arbitrarily set.

  In the infrared distance sensor of this example, the infrared rays transmitted from the transmission unit 23a hit the viewer V and are reflected. The reflected light from the viewer V is received by the four receiving units 23b described above, and the receiving unit 23b showing the highest receiving sensitivity among the four receiving units 23b is specified. A right triangle is formed by the specified receiver 23b, transmitter 23a, and viewer V, and the lengths Y and Z of the other two sides can be obtained from the length X and angle θ of one side of the right triangle. .

  As described above, when the length X, which is the distance between the receiving unit 23b and the transmitting unit 23a that exhibits the highest reception sensitivity, and the angle θ between the receiving unit 23b and the viewer V are determined, the length X and the angle θ are determined. Based on this, it is possible to calculate the length Y, which is the distance (viewing distance) between the display panel 22 (transmitting unit 23a) and the viewer V, and the length Z, which is the distance between the receiving unit 23b and the viewer V. it can. The display device 10 resizes the size of the input image signal based on the viewing distance calculated by the viewing distance calculation unit 23 and displays it on the display panel 22.

  FIG. 8 is a diagram illustrating another configuration example of the viewing distance calculation unit 23 and shows a state in which the display panel 22 is viewed from the side. The viewing distance calculation unit 23 of this example is a distance sensor that can measure the distance between two points using ultrasonic waves or sound waves, and transmits the ultrasonic waves or sound waves toward the viewer V. And a receiving unit 23b for receiving the transmitted ultrasonic wave or the reflected wave from the viewer V of the sound wave.

  In the ultrasonic type or acoustic type distance sensor of this example, the ultrasonic wave or sound wave transmitted from the transmission unit 23a hits the viewer V and is reflected. The reflected wave from the viewer V is received by the receiving unit 23b. The time difference between the transmission unit 23a and the reception unit 23b at this time is obtained, and the viewing distance between the display panel 22 and the viewer V can be calculated from the obtained time difference. The display device 10 resizes the size of the input image signal based on the viewing distance calculated by the viewing distance calculation unit 23 and displays it on the display panel 22.

  FIG. 9 is a diagram illustrating an example of a viewing distance calculation method by the viewing distance calculation unit 23 and the remote control device. In the figure, the display device 10 includes an operation signal receiving unit 27 for receiving an operation signal from a remote operation device (remote control) 28. The viewing distance calculation unit 23 may calculate the viewing distance between the display device 10 and the viewer V using this as a trigger when a predetermined operation signal is received from the remote controller 28. The predetermined operation signal is an operation signal corresponding to, for example, a power button or a specific operation button (hereinafter represented by the power button 28a), and the viewer V presses the power button 28a of the remote control 28 to display the display device. When the power of 10 is turned on, the display device 10 calculates a viewing distance from the viewer V, performs a resizing process on the input image signal according to the calculated viewing distance, and displays the result on the display panel 22.

  Here, the display device 10 may perform the process of calculating the viewing distance by the viewing distance calculation unit 23 when the display device 10 is turned on, and then automatically and repeatedly perform the predetermined cycle. Alternatively, it may be performed at a desired timing by the viewer V, such as when the viewer V changes the viewing position.

  FIG. 10 is a flowchart for explaining an example of the display control method by the display device 10. First, the display device 10 determines whether or not a predetermined operation signal (operation signal corresponding to the power button 28a) has been received from the remote controller 28 (step S1). When the operation signal is received (in the case of YES), the display device 10 displays. The viewing distance between the device (TV) 10 and the viewer V is calculated (step S2). In step S1, when an operation signal is not received (in the case of NO), a transition is made to a standby state in step S1.

  Next, the display device 10 resizes the size of the input image signal in accordance with the calculated viewing distance (step S3), and displays and outputs the resized input image signal on the display panel 22 (step S4).

As described above, according to the present invention, since the size of the input image signal can be controlled according to the viewing distance so as to always maintain an appropriate viewing angle, it is optimal even when viewing a large screen TV at a short distance. A viewing angle can be secured. As a result, the scanning line is inconspicuous, or the frequency of moving the eyes and neck is drastically reduced, which is effective for reducing the viewer's fatigue and preventing a reduction in visual acuity.
In addition, when viewing a large screen TV at a short distance, the lighting location of the backlight can be controlled according to the display range of the resized image, so that power consumption can be reduced.
Further, by not turning on the backlight other than the display range of the resized image, the periphery of the display range becomes almost black, and stray light can be reduced and eye fatigue can be reduced.

It is a block diagram which shows the structural example of the display apparatus which concerns on one Embodiment of this invention. It is the figure which showed a mode that the size of the input image signal changed with viewing distance. It is a figure which shows an example of the message displayed when viewing distance is smaller than predetermined distance. It is a figure which shows the structural example of the display panel at the time of using LED for a backlight light source. It is a figure which shows the structural example of the display panel at the time of using a cold cathode tube for a backlight light source. It is a figure which shows the other structural example of the display panel at the time of using a cold cathode tube for a backlight light source. It is a figure which shows the structural example of a viewing distance calculation part. It is a figure which shows the other structural example of a viewing distance calculation part. It is a figure which shows an example of the calculation method of the viewing distance by a viewing distance calculation part and a remote control device. It is a flowchart for demonstrating an example of the display control method by a display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Display apparatus, 11 ... YC separation part, 12, 14 ... Selector, 13 ... ADC (AD converter), 15 ... IP conversion part, 16 ... Resizer, 17 ... Image quality adjustment part, 18 ... Scaler, 19 ... Gamma correction part , 20 ... OSD (on-screen display) section, 21 ... T-CON (timing controller), 22 ... display panel, 22a ... display area, 23 ... viewing distance calculation section, 23a ... transmission section, 23b ... reception section, 24 ... Memory, 25 ... Control part, 26a-26i ... Backlight light source, 27 ... Operation signal receiving part, 28 ... Remote operation device (remote control), 28a ... Operation button (power button).

Claims (11)

  In a display device having a display panel for displaying an input image signal, viewing distance calculation means for calculating a viewing distance between the display device and a viewer, and resizing the size of the input image signal according to the calculated viewing distance And a resizing means for displaying the resized input image signal on the display panel.   The display device according to claim 1, further comprising storage means for storing a viewing distance between the display device and a viewer and size information of an input image signal, wherein the resizing means refers to the storage means. Accordingly, the display device is characterized in that the size information of the input image signal corresponding to the viewing distance calculated by the viewing distance calculation means is acquired, and the input image signal is resized based on the size information.   3. The display device according to claim 1, further comprising a light source that illuminates the display panel, and the light source is turned on / off so as to illuminate only a region for displaying the input image signal resized by the resizing unit. A display device that is controlled.   4. The display device according to claim 3, wherein the light source is any one of a combination of a light emitting diode (LED), a cold cathode tube, an LED, and a cold cathode tube.   2. The display device according to claim 1, wherein the viewing distance calculation unit is a distance sensor capable of measuring a distance between two points using infrared rays, and a transmission unit that transmits infrared rays to a viewer; and A display device comprising: a plurality of receiving units that receive reflected light from the viewer of transmitted infrared rays.   2. The display device according to claim 1, wherein the viewing distance calculating means is a distance sensor capable of measuring a distance between two points using ultrasonic waves or sound waves, and transmits the ultrasonic waves or sound waves to a viewer. A display device comprising: a transmitting unit that receives a reflected wave from the viewer of the transmitted ultrasonic wave or sound wave.   The display device according to claim 1, wherein when the viewing distance calculated by the viewing distance calculation unit is smaller than a predetermined distance, a message for prompting the user to leave the display device is displayed on the display panel. A display device.   8. The display device according to claim 1, further comprising OSD means for superimposing an on-screen signal on an input image signal, wherein the OSD means displays the input image signal resized by the resizing means. A display device characterized by superimposing frame information around a frame.   9. The display device according to claim 8, wherein the OSD means superimposes a predetermined color signal as the frame information.   10. The display device according to claim 1, further comprising a remote operation device for remotely operating the display device, wherein the viewing distance calculating means receives a predetermined operation signal from the remote operation device. Sometimes, the display device calculates a viewing distance between the display device and the viewer.   In a display control method using a display device having a display panel for displaying an input image signal, a step of calculating a viewing distance between the display device and a viewer, and a size of the input image signal according to the calculated viewing distance. A display control method comprising the steps of resizing and displaying the resized input image signal on the display panel.

Images