JP2009296116A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of preventing user's eyes from getting fatigued and also preventing a user from feeling sense of incongruity when he/she resumes viewing and listening after he/she stops the viewing and listening once. <P>SOLUTION: A liquid crystal television 100 (display device) comprises a liquid crystal panel 17, a microcomputer 21 for adjusting brightness of the liquid crystal panel 17, and a detection unit 20 for detecting whether a user locates in a predetermined region or not. If the detection unit 20 detects that the user locates in the predetermined region, the microcomputer 21 is configured to lower the brightness of the liquid crystal panel 17 after a predetermined period is past. If the detection unit 20 detects that the user does not locate in the predetermined region, the microcomputer 21 is configured to return the brightness of the liquid crystal panel 17 to a reference value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device having a function of adjusting luminance of a display unit.

  Conventionally, various display devices including a display unit and a control unit that adjusts the luminance of the display unit are known (see, for example, Patent Documents 1 to 3).

  Patent Documents 1 to 3 disclose display devices configured to gradually reduce the luminance of the display unit from a reference value to a predetermined value. For this reason, in the display apparatus of the said patent documents 1-3, it is possible to suppress that a user's eyes get tired, suppressing a user's feeling of discomfort resulting from the fall of a brightness | luminance.

Japanese Patent Laid-Open No. 11-341393 JP 2005-236520 A JP 2007-104067 A

  However, in the conventional display devices disclosed in Patent Documents 1 to 3, for example, when the user leaves the place and stops viewing without turning off the power of the display device, the viewing is temporarily stopped. Since the brightness of the display unit decreases while the user is stopped, when the user returns and then resumes viewing, the brightness of the display unit may decrease significantly and the user may feel uncomfortable. There is a problem that there is.

  The present invention solves the above-described problems, and the object of the present invention is to suppress fatigue of the user's eyes and to be used when the user temporarily stops viewing and then resumes viewing. It is an object of the present invention to provide a display device that can prevent a person from feeling uncomfortable.

  The display device of the present invention is a display device including a display unit and a control unit for adjusting the luminance of the display unit. Whether or not the user is present in a predetermined area positioned when the user views And a control unit configured to reduce the luminance of the display unit every predetermined period when the detection unit detects that a user is present in the predetermined region. When the detection unit detects that there is no user in the predetermined area, the luminance of the display unit is not reduced.

  With this configuration, when the user is viewing and viewing in a predetermined area, the luminance of the display unit decreases every time a predetermined period elapses, so the user feels uncomfortable due to the decrease in luminance. It is possible to suppress fatigue of the user's eyes while suppressing the feeling. In addition, when the user once leaves the predetermined area and stops viewing, the luminance of the display unit does not decrease. Therefore, even when the user returns to the predetermined area and resumes viewing, the user decreases the luminance. It is possible to suppress a sense of incongruity caused by.

  In the display device, preferably, the display unit is configured to be adjustable in a range between the first value and the second value smaller than the first value, and the control unit is configured to be controlled by the detection unit. When it is detected that a user is present in a predetermined area, the luminance of the display unit is decreased every predetermined period so that the luminance of the display unit changes from the first value to the second value. When the detection unit detects that no user is present in the predetermined area, the luminance of the display unit is returned to the first value.

  With this configuration, when the user once leaves the predetermined area and stops viewing, the luminance of the display unit returns to the first value (reference value), and then the user returns to the predetermined area. When viewing is resumed, the user can be prevented from feeling uncomfortable due to a decrease in luminance.

  In the display device, preferably, the detection unit is configured to be able to detect the distance to the user existing in the predetermined area, and the control unit is based on the distance to the user detected by the detection unit, The display unit is configured to adjust the amount of decrease in luminance of the display unit.

  By configuring in this way, when the user is viewing in a state of being close to the display unit, it is possible to further suppress fatigue of the user's eyes by increasing the amount of decrease in luminance of the display unit. be able to.

  In the display device, preferably, the detection unit is configured to be able to detect illuminance around the display unit, and the control unit is configured to detect the illuminance around the display unit detected by the detection unit. The luminance reduction amount is adjusted.

  By comprising in this way, when a periphery is dark, it can suppress that a user's eyes get tired more by enlarging the fall amount of the brightness | luminance of a display part.

  According to the present invention, there is provided a display device capable of suppressing fatigue of the user's eyes and suppressing the user from feeling uncomfortable even when the user temporarily stops viewing and then resumes viewing. Can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a case where the present invention is applied to a liquid crystal television receiver (hereinafter referred to as “liquid crystal television”) which is an example of a display device will be described.

  FIG. 1 is a perspective view showing an overall configuration of a liquid crystal television according to an embodiment of the present invention. FIG. 2 is a block diagram showing the overall configuration of the liquid crystal television of FIG. FIG. 3 is a plan view showing a television body of the liquid crystal television of FIG. First, the configuration of the liquid crystal television 100 according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 1, a liquid crystal television 100 according to an embodiment of the present invention includes a television main body 1 that receives and displays a television broadcast and a remote controller 2 that remotely operates the television main body 1.

  As shown in FIG. 2, the television body 1 includes a bridge rectifier circuit 11, an inverter circuit 12, a backlight 13, a tuner 14, a video processing circuit 15, a drive circuit 16, a liquid crystal panel 17, and a receiving unit. 18, a counter 19, a detection unit 20, and a microcomputer (hereinafter referred to as “microcomputer”) 21. The liquid crystal panel 17 is an example of the “display unit” in the present invention, and the microcomputer 21 is an example of the “control unit” in the present invention.

  The bridge rectifier circuit 11 includes four diodes and the like, and is configured to convert electric power supplied from the AC power source 150 from AC to DC and output the inverter circuit 12. Although omitted in FIG. 2, the bridge rectifier circuit 11 supplies power to the microcomputer 21 and the like.

  The inverter circuit 12 is provided to convert the DC voltage supplied from the bridge rectifier circuit 11 into a high-voltage AC voltage and supply it to the backlight 13. The backlight 13 is provided for irradiating light from the back surface of the liquid crystal panel 17. The backlight 13 includes a cold cathode tube and the like, and is configured such that the cold cathode tube is turned on by a voltage supplied from the inverter circuit 12.

  The tuner 14 has a function of selecting a television broadcast channel received by the antenna 151 and outputting a video signal of the selected channel to the video processing circuit 15. The video processing circuit 15 is configured to perform predetermined processing on the video signal input from the tuner 14 and output the video signal on which the predetermined processing has been performed to the drive circuit 16. The video processing circuit 15 has a function of superimposing the OSD signal on the video signal when an OSD (On-Screen Display) signal is supplied from the microcomputer 21.

  The drive circuit 16 has a function of generating a drive signal for controlling the aperture ratio of each dot of the liquid crystal panel 17 based on the video signal input from the video processing circuit 15. The liquid crystal panel 17 is configured to display an image by transmitting light emitted from the backlight 13 according to a drive signal.

  The receiving unit 18 has a function of receiving a remote control signal output from the remote controller 2 and outputting it to the microcomputer 21. The counter 19 is provided for measuring the elapsed time.

  Here, in this embodiment, the detection part 20 is provided in the front surface of the television main body 1, as shown in FIG. As shown in FIG. 3, the detection unit 20 has a function of detecting whether or not the user P is present in the predetermined region R. The predetermined area R is an area located when the user P views the liquid crystal television 100. Specifically, the detection unit 20 includes a light receiving element such as a CCD image sensor or a CMOS image sensor, and is configured to be able to image the predetermined region R. And the detection part 20 is comprised so that the user P may exist in the predetermined area | region R using an image recognition technique.

  In the present embodiment, the detection unit 20 has a function of detecting the distance D to the user P existing in the predetermined region R. Specifically, the detection unit 20 includes a light projecting element such as a light emitting diode or a semiconductor laser in addition to the light receiving element. And the detection part 20 is comprised so that the distance D to the user P may be detected using a triangulation method. The detection unit 20 has a function of detecting the illuminance around the liquid crystal panel 17 (see FIG. 2).

  As shown in FIG. 2, the microcomputer 21 has a function of controlling the operation of the television main body 1. The microcomputer 21 has a function of adjusting the brightness of the liquid crystal panel 17 by controlling the inverter circuit 12 and the video processing circuit 15. Specifically, the microcomputer 21 is configured to adjust the luminance of the liquid crystal panel 17 within a range between a reference value and a predetermined value (for example, 80% of the reference value). The reference value is an example of the “first value” in the present invention, and the predetermined value is an example of the “second value” in the present invention.

  Further, in the present embodiment, when the user P exists in the predetermined region R, the microcomputer 21 sets the distance D to the user P and the ambient illuminance every time a predetermined period (for example, 30 minutes) elapses. Based on this, the brightness of the liquid crystal panel 17 is reduced. Specifically, when the distance D to the user P is large, the amount of decrease in the luminance of the liquid crystal panel 17 is reduced, and when the distance D to the user P is small, the amount of decrease in the luminance of the liquid crystal panel 17. Increase Further, when the peripheral illuminance is high, the amount of decrease in the luminance of the liquid crystal panel 17 is reduced, and when the peripheral illuminance is small, the decrease in the luminance of the liquid crystal panel 17 is increased. Further, the microcomputer 21 is configured to return the luminance of the liquid crystal panel 17 to the reference value when the user P is not present in the predetermined region R.

  FIG. 4 is a flowchart for explaining the brightness control operation of the liquid crystal television according to the embodiment of the present invention. Next, the brightness control operation of the liquid crystal television 100 according to the present embodiment will be described with reference to FIGS.

  First, in the liquid crystal television 100 (see FIG. 2), the reception unit 18 (see FIG. 2) turns on the power from the remote controller 2 (see FIG. 2) by the microcomputer 21 (see FIG. 2) in step S1 of FIG. It is determined whether or not a remote control signal indicating is received. If the microcomputer 21 determines that the receiving unit 18 has received the remote control signal, driving of the liquid crystal panel 17 (see FIG. 2) is started, and then the process proceeds to step S2. On the other hand, if the microcomputer 21 determines that the receiving unit 18 has not received the remote control signal, step S1 is repeated.

  Next, in step S2, the microcomputer 19 resets the counter 19 (see FIG. 2). In step S3, the microcomputer 21 sets the luminance of the liquid crystal panel 17 to a reference value.

  Next, in step S4, the microcomputer 21 determines whether or not the user P (see FIG. 3) exists in the predetermined region R (see FIG. 3) using the detection unit 20 (see FIG. 2). If the microcomputer 21 determines that the user P exists in the predetermined area R, the process proceeds to step S5. On the other hand, when the microcomputer 21 determines that the user P does not exist in the predetermined region R, the brightness of the liquid crystal panel 17 is reset to the reference value in step S12, and then the process proceeds to step S10. In step S12, when the brightness of the liquid crystal panel 17 is lower than the reference value, the brightness is returned to the reference value, and when the brightness of the liquid crystal panel 17 is the reference value, the brightness remains at the reference value. Is done.

  Next, in step S5, the microcomputer 21 determines whether or not a predetermined period (30 minutes) has elapsed using the counter 19. When the microcomputer 21 determines that the predetermined period has elapsed, the process proceeds to step S6. On the other hand, if the microcomputer 21 determines that the predetermined period has not elapsed, the process proceeds to step S11.

  Next, in step S6, the microcomputer 21 determines whether or not the luminance of the liquid crystal panel 17 is a predetermined value (80% of the reference value). If the microcomputer 21 determines that the luminance of the liquid crystal panel 17 is not a predetermined value, the process proceeds to step S7. On the other hand, when the microcomputer 21 determines that the luminance of the liquid crystal panel 17 is a predetermined value, the process proceeds to step S10.

  Next, in step S <b> 7, the microcomputer 21 measures the distance D (see FIG. 3) to the user P using the detection unit 20. In step S <b> 8, the microcomputer 21 measures the illuminance around the liquid crystal panel 17 using the detection unit 20.

  Next, in step S9, the microcomputer 21 reduces the brightness of the liquid crystal panel 17 based on the distance D to the user P and the ambient illuminance. Specifically, if the distance D to the user P is large, the amount of decrease in the luminance of the liquid crystal panel 17 is reduced, and if the distance D to the user P is small, the amount of decrease in the luminance of the liquid crystal panel 17 is increased. . Further, if the peripheral illuminance is large, the amount of decrease in the luminance of the liquid crystal panel 17 is reduced. If the peripheral illuminance is small, the amount of decrease in the luminance of the liquid crystal panel 17 is increased. This reduction in luminance is performed so that the luminance of the liquid crystal panel 17 does not become lower than a predetermined value (80% of the reference value).

  For example, when the distance D to the user P is within a predetermined range (for example, 1 m to 2 m) in step S7, and the ambient illuminance is within a predetermined range (for example, 150 Lx to 300 Lx) in step S8. The microcomputer 21 reduces the brightness of the liquid crystal panel 17 by a predetermined amount (for example, 5% of the reference value).

  If the distance D to the user P is within a predetermined range (1 m to 2 m) in step S7 and the surrounding illuminance is large (greater than 300 Lx) in step S8, the microcomputer 21 causes the brightness of the liquid crystal panel 17 to be increased. Is reduced by a predetermined amount (4% of the reference value). If the distance D to the user P is within a predetermined range (1 m to 2 m) in step S7 and the ambient illuminance is small (less than 150 Lx) in step S8, the microcomputer 21 causes the brightness of the liquid crystal panel 17 to be increased. Is reduced by a predetermined amount (6% of the reference value).

  If the distance D to the user P is large (greater than 2 m) in step S7 and the surrounding illuminance is within a predetermined range (150Lx to 300Lx) in step S8, the microcomputer 21 causes the brightness of the liquid crystal panel 17 to increase. Is reduced by a predetermined amount (4% of the reference value). If the distance D to the user P is small (less than 1 m) in step S7 and the surrounding illuminance is within a predetermined range (150Lx to 300Lx) in step S8, the microcomputer 21 causes the brightness of the liquid crystal panel 17 to be increased. Is reduced by a predetermined amount (6% of the reference value).

  If the distance D to the user P is large (greater than 2 m) in step S7 and the surrounding illuminance is large (greater than 300 Lx) in step S8, the microcomputer 21 sets the luminance of the liquid crystal panel 17 to a predetermined amount (reference value). 3%). If the distance D to the user P is small (less than 1 m) in step S7 and the surrounding illuminance is small (less than 150 Lx) in step S8, the microcomputer 21 controls the luminance of the liquid crystal panel 17 by a predetermined amount (reference value). 7%).

  In step S7, when the distance D to the user P is large (greater than 2 m) and the ambient illuminance is small (less than 150 Lx) in step S8, the microcomputer 21 controls the luminance of the liquid crystal panel 17 by a predetermined amount (reference value). 5%). Further, when the distance D to the user P is small (less than 1 m) in step S7 and the surrounding illuminance is large (greater than 300 Lx) in step S8, the microcomputer 21 controls the luminance of the liquid crystal panel 17 by a predetermined amount (reference value). 5%).

  Next, in step S <b> 10, the counter 19 is reset by the microcomputer 21. In step S <b> 11, the microcomputer 21 determines whether or not the receiving unit 18 has received a remote control signal indicating that the power is turned off from the remote control 2. When the microcomputer 21 determines that the receiving unit 18 has not received the remote control signal, the process returns to step S4. On the other hand, when the microcomputer 21 determines that the receiving unit 18 has received the remote control signal, the driving of the liquid crystal panel 17 is stopped and the luminance control operation ends.

  In the present embodiment, as described above, when the user P is viewing the liquid crystal television 100 in the predetermined region R (step S4: Yes), a predetermined period (30 minutes) elapses (step Every time (S5: Yes), the brightness of the liquid crystal panel 17 is reduced by a predetermined amount until the brightness of the liquid crystal panel 17 reaches a predetermined value from the reference value (step S9). It is possible to suppress fatigue of the eyes of the user P while suppressing the feeling of discomfort.

  When the distance D to the user P is always within a predetermined range (1 m to 2 m) and the surrounding illuminance is always within the predetermined range (150 Lx to 300 Lx), the liquid crystal panel 17 is every 30 minutes. The brightness of the liquid crystal panel 17 becomes a predetermined value (80% of the reference value) 120 minutes after the start of viewing. Then, when the user P is present in the predetermined region R (step S4: Yes), the luminance of the liquid crystal panel 17 is not decreased (step S6: Yes), and the luminance of the liquid crystal panel 17 is predetermined. Maintained by value.

  In the present embodiment, when the user P leaves the predetermined area R and stops viewing (step S4: No), the brightness of the liquid crystal panel 17 returns to the reference value (step S12). When the user P then returns to the predetermined region R and resumes viewing, the user P can be prevented from feeling uncomfortable due to a decrease in luminance.

  Note that while the user P does not exist in the predetermined region R (step S4: No), the luminance of the liquid crystal panel 17 is maintained at the reference value (step S12). In other words, in the liquid crystal television 100 according to the present embodiment, the luminance of the liquid crystal panel 17 decreases every time a predetermined period elapses while the user P exists in the predetermined region R.

  Further, in the present embodiment, when the distance D to the user P is small, the eye of the user P who is viewing in the state of being close to the liquid crystal television 100 by increasing the amount of decrease in the luminance of the liquid crystal panel 17. Can be further suppressed from fatigue.

  Further, in the present embodiment, the user P's eyes are increased by increasing the amount of decrease in the brightness of the liquid crystal panel 17 when the ambient illuminance is small, such as when viewing the liquid crystal television 100 in a dark room. Can be further suppressed from fatigue.

  The present invention can adopt various embodiments other than those described above. For example, the various values in the above embodiment are examples, and other values may be used. Specifically, in the above embodiment, when the distance D to the user P is within a predetermined range (1 m to 2 m) and the surrounding illuminance is within a predetermined range (150 Lx to 300 Lx), Although an example in which the luminance of the liquid crystal panel 17 is decreased by a predetermined amount (5% of the reference value) every time the period (30 minutes) elapses is shown, the present invention is not limited thereto, and a predetermined period (6 minutes) elapses Each time, the luminance of the liquid crystal panel 17 may be decreased by a predetermined amount (1% of the reference value). If comprised in this way, it can suppress more that the user P senses the uncomfortable feeling resulting from the fall of a brightness | luminance.

  In the above embodiment, when the brightness of the liquid crystal panel 17 reaches a predetermined value (80% of the reference value), or when a predetermined time (for example, 2 hours) has elapsed since the start of viewing. A display prompting the user P to take a break may be displayed on the liquid crystal panel 17.

  In the above-described embodiment, the example in which the luminance of the liquid crystal panel 17 is returned to the reference value when the user P does not exist in the predetermined region R is shown. However, the present invention is not limited thereto, and the user P exists in the predetermined region R. If not, the brightness of the liquid crystal panel 17 may be maintained at the current brightness.

  Moreover, although the example which adjusts the fall amount of the brightness | luminance of the liquid crystal panel 17 based on the distance D to the user P and surrounding illumination intensity was shown in the said embodiment, not only this but the distance to the user P The amount of decrease in the luminance of the liquid crystal panel 17 may be adjusted based on only D, or the amount of decrease in the luminance of the liquid crystal panel 17 may be adjusted based on only the surrounding illuminance. Further, the amount of decrease in luminance of the liquid crystal panel 17 may be made constant.

It is the perspective view which showed the whole structure of the liquid crystal television by one Embodiment of this invention. It is the block diagram which showed the whole structure of the liquid crystal television of FIG. It is the top view which showed the television main body of the liquid crystal television of FIG. 5 is a flowchart for explaining a brightness control operation of the liquid crystal television according to the embodiment of the present invention.

Explanation of symbols

17 LCD panel (display unit)
20 detection unit 21 microcomputer (control unit)
100 LCD TV (display device)

Claims (4)

A display unit;
In a display device comprising a control unit for adjusting the luminance of the display unit,
A detection unit for detecting whether or not the user is present in a predetermined area located when the user views;
The control unit is configured to reduce the luminance of the display unit every predetermined period when the detection unit detects that a user is present in the predetermined region, and the detection unit A display device configured to prevent a reduction in luminance of the display unit when it is detected that no user is present in a predetermined area. The display device according to claim 1,
The display unit is configured to be adjustable within a range between a first value and a second value smaller than the first value.
When the detection unit detects that a user is present in the predetermined region, the control unit elapses a predetermined period so that the luminance of the display unit changes from the first value to the second value. The display unit is configured to reduce the luminance of the display unit every time and when the detection unit detects that no user is present in the predetermined area, the luminance of the display unit is returned to the first value. A display device configured as described above. The display device according to claim 1 or 2,
The detection unit is configured to be able to detect a distance to a user existing in the predetermined area,
The control unit is configured to adjust a decrease in luminance of the display unit based on a distance to a user detected by the detection unit. The display device according to any one of claims 1 to 3,
The detection unit is configured to detect illuminance around the display unit,
The control unit is configured to adjust a decrease in luminance of the display unit based on illuminance around the display unit detected by the detection unit.

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