JP2010011209A - Illuminance sensor unit, and display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently adjust luminance of a display by sufficiently detecting brightness of a surrounding area. <P>SOLUTION: This application uses the illuminance sensor unit equipped with an illuminance sensor, and a biconcave lens arranged oppositely to the illuminance sensor. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device such as a cathode ray tube and a liquid crystal display device, and an illuminance sensor unit used therefor.

  In a display device such as a cathode ray tube and a liquid crystal display device, a phenomenon occurs in which the display becomes difficult to see depending on the brightness of the surroundings. For example, when the surroundings are bright, it is difficult to see when the brightness of the display is low. On the other hand, when the periphery of the display is dark, if the luminance of the display is high, it is too bright and difficult to see.

  For this reason, there is a technique in which an illuminance sensor is provided in a display device to detect ambient brightness, and the brightness of the display is adjusted according to the detected brightness (see, for example, Patent Document 1).

However, this illuminance sensor cannot sense the brightness sufficiently unless the outside light reaches enough. For example, when the luminaire is placed above the display device, the incident angle of the external light incident on the illuminance sensor is too sharp, so that the external light hardly reaches the illuminance sensor and senses ambient brightness. It was difficult. As described above, in the conventional display device, the brightness adjustment of the display according to the ambient brightness is insufficient.
Japanese Patent Laid-Open No. 8-130693

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display device capable of adjusting the brightness of a display according to ambient brightness and an illuminance sensor unit therefor.

  The illuminance sensor unit of the present invention includes an illuminance sensor and a biconcave lens provided to face the illuminance sensor.

  The display device of the present invention includes a display unit, an illuminance sensor unit provided in the vicinity of the display unit, having an illuminance sensor, a biconcave lens provided to face the illuminance sensor, and detection information from the illuminance sensor And a control unit for controlling the brightness of an image displayed on the display unit.

  According to the present invention, the brightness of the display can be sufficiently adjusted by sufficiently detecting the ambient brightness.

  The illuminance sensor unit of the present invention has an illuminance sensor and a biconcave lens provided to face the illuminance sensor.

  In addition, the display device of the present invention includes a display unit, an illuminance sensor unit provided in the vicinity of the display unit, having an illuminance sensor, a biconcave lens provided to face the illuminance sensor, and detection information from the illuminance sensor. And a control unit for controlling the brightness of the video displayed on the display unit.

  According to the present invention, the external light incident on the illuminance sensor unit at a sharp angle is refracted and reaches the illuminance sensor by the biconcave lens provided facing the illuminance sensor. It can be fully detected. For this reason, the brightness adjustment of the display according to the surrounding brightness is good.

  Hereinafter, the present invention will be described in more detail with reference to the drawings.

  In FIG. 1, the schematic showing the structure of the illumination intensity sensor unit concerning this invention is shown.

  As shown in the drawing, the illuminance sensor unit 10 includes an illuminance sensor 2 mounted on an illuminance sensor 2 mounted on a substrate 3 provided inside a front panel in the display device and a front panel 4 having a display surface (not shown). And a biconcave lens 1 provided so as to face the lens. The biconcave lens 1 is disposed, for example, around the display surface of the front panel 4 and is fixed in an opening provided in a part of the front panel 4. External light passes through the biconcave lens 1 and reaches the illuminance sensor 2.

  FIG. 2 shows an example of the state of light that is refracted through a biconcave lens.

  As shown in the figure, external light L1 incident on the both surfaces of the biconcave lens 1 having focal points F and F ′ at positions h from the center of the lens, for example, obliquely toward the focal point F ′. , Exit the lens in parallel along the central axis of the lens. Further, in the case of the external light L2 that is incident at a duller angle than the external light L1, the light is slightly refracted toward the center axis of the lens and passes through the lens. The external light L3 passing through the center of the lens goes straight as it is. As described above, when the illuminance sensor panel according to the present invention is used, a part of the external light incident in the oblique direction is refracted along the central axis of the lens or near the central axis of the lens and reaches the illuminance sensor 2. Therefore, the brightness adjustment of the display according to the ambient brightness is good.

  FIG. 3 is a diagram illustrating another example of the state of light that is refracted through the biconcave lens.

  Here, the state of light when a light source is placed at the focal point F of a biconcave lens having a concave portion with a height h and a diameter r is shown.

  As shown in FIG. 3, the biconcave lens used in the present invention has a divergence action that spreads light. The focal point F of the concave lens is in front of the lens as shown, and the light rays diverge so as to spread from the focal point. The focal point is changed by changing the height h from the center of the lens to the apex, and the focal length from the center of the lens to the focal point F is known as the distance at which the diameter of the refracted light spread is twice 2r of the lens diameter. I can do it. As the height h from the lens bottom to the lens apex is increased, the focal length is closer to the lens and the amount of light divergence can be increased.

  From these facts, it can be seen that the smaller the focal length, the higher the refractive index, and the wider the incident angle when viewed from the sensor side.

  In other words, the incident angle can be increased as the height h from the lens center to the apex is larger.

  FIG. 4 is a graph showing the relationship between the angle of the light source and the screen brightness.

  This is a measurement of the luminance of a display device such as a cathode ray tube or a liquid crystal display device at that time by changing the angle of the light source with respect to the biconcave lens provided facing the illuminance sensor using the same light source. is there.

  The angle of the light source is an angle between a line connecting the light source and the center of the biconcave lens and a line perpendicular to the center of the biconcave lens.

  In the figure, 101 is a biconcave lens having a diameter of 5.0 mm and a height h of 1.2 mm from the center, and 102 is a biconcave lens having a diameter of 5.0 mm and h is 0.6 mm. In the case 103, for comparison, a case where a transparent cover is attached to the opening for the open illuminance sensor unit on the front panel instead of the biconcave lens is shown.

  As shown in the figure, since the amount of divergence increases as the size of the lens increases, it is better to make it as large as possible. However, it is necessary to balance with the design of the display device.

  For example, in the case of a display having a screen size of 406.4 mm × 304.8 mm to 540.8 mm × 405.6 mm, for example, when an incident angle of 60 degrees or more is required, a diameter of 1.0 mm to 5.0 mm, The diameter can be 5 mm, h = 0.3 mm to 1.6 mm, and h = 1.2 mm.

  If the lens diameter exceeds 5.0 mm, the internal illuminance sensor and other parts will be visible from the outside, so the design will be poor, and if it is less than 1.0 mm, external light will not reach the illuminance sensor sufficiently. There is.

  In addition, when the lens diameter is 5.0 mm, if h = less than 0.3 mm, the effect of the biconcave lens cannot be obtained, and light incident at a sharp angle tends not to reach the illuminance sensor sufficiently. is there.

  FIG. 5 is a front view showing the appearance of the display device according to the present invention.

  FIG. 6 is a block diagram showing the configuration of the display device according to the present invention.

  As shown in the figure, the display device of the present invention, for example, a television receiver such as a liquid crystal display element or a cathode ray tube has a display surface 4 of, for example, a size of 540.8 mm × 405.6 mm and the vicinity of the display surface 4 such as a display surface. 4 is an illuminance sensor unit 10 provided on the lower right front panel, a remote control light receiving unit 12 provided adjacent thereto, and three types of LEDs provided on the lower left side to represent power-on, standby, and timer, respectively. There is a lamp.

  In FIG. 6, 24 is a tuner. The intermediate frequency signal output from the tuner 24 is supplied to the video intermediate frequency amplification circuit 25 and amplified. The video intermediate frequency signal amplified by the video intermediate frequency amplifying circuit 25 is detected by the video detection video processing IC 22 and amplified as a video signal, separation processing from the video signal into a luminance signal and a color signal, and a color signal Demodulation processing, luminance signal and color difference signal matrix processing, and the like are performed to form a red signal, a green signal, and a blue signal. These color signals are supplied to a display unit 23 such as a cathode ray tube or a liquid crystal display device, and a color image corresponding to the color signals is displayed on the screen.

  The video detection video processing IC 22 is connected to the microcomputer 21, and the microcomputer 21 is connected to the remote control light receiving unit 12 that receives a remote control signal from the remote control 27 and the illuminance sensor 2. The illuminance sensor unit 10 includes the illuminance sensor 2 and the biconcave lens 1 fixed to the front panel on the lower right side of the display surface 4. Here, for example, when the illuminance sensor 2 senses external light incident at an acute angle with respect to the front panel from a light source provided above the display device through the biconcave lens 1, the voltage of the signal line is changed according to the amount of light. . This change in voltage is AC converted by the microcomputer 21 and sent to the video detection video processing IC 22 as an illuminance detection signal. The video detection video processing IC 22 can send a luminance signal based on the illuminance detection signal to the display unit as a control unit that controls the brightness of the video displayed on the display unit. Thereby, for example, even when the incident angle of external light incident on the illuminance sensor is sharp, the brightness of the surroundings can be sufficiently detected and the brightness of the display can be adjusted.

Schematic showing the structure of the illumination intensity sensor unit concerning this invention. The figure showing an example of the state of the light which refracts | transmits through a biconcave lens The figure showing another example of the state of the light which refracts | transmits through a biconcave lens Graph showing the relationship between light source angle and screen brightness The front view showing the external appearance of the display apparatus concerning this invention The block diagram showing the structure of the display apparatus which concerns on this invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Biconcave lens, 2 ... Illuminance sensor, 10 ... Illuminance sensor unit, 23 ... Display part, 32 ... Control part, 20 ... Display apparatus

Claims (2)

  An illuminance sensor unit comprising: an illuminance sensor; and a biconcave lens provided to face the illuminance sensor.   An illuminance sensor unit having a display unit, an illuminance sensor provided in the vicinity of the display unit, a biconcave lens provided to face the illuminance sensor, and detection information from the illuminance sensor. A display device comprising: a control unit that controls brightness of a displayed image.

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