JP3104248B2 - Optical filter device and display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is applied to an optical filter device which is attached to the front of a display screen such as a CRT of a television monitor to adjust a video output state, and to which the optical filter device is applied. The present invention relates to a display device.

[Summary of the Invention] An optical filter device according to the present invention comprises an optical filter means having a transmission panel capable of electrically variably controlling the light transmittance mounted on the front surface of a monitor display screen; And a filter driving means for setting and driving the transmittance of the optical filter means based on the supplied light transmittance setting information and the external light detection signal. By setting the rate to be variable, if the light transmittance setting information can be obtained from the picture, brightness, color tone of the output image, the state of the external light of the monitor device, and the manual operation, the light of the optical filter can be obtained. The transmittance can always be set to the optimum state.

[Prior art] Conventionally, a filter is provided on the front of a CRT display screen or a special processing is performed on the CRT surface in order to prevent influence of external light on an image, adjust a light amount, and adjust a contrast. Has been done.

As the filter, for example, a glass plate of a dark screen with reduced transmittance, a Venetian blind to prevent reflection of external light by using deflected plastic, etc. are implemented. There is also a so-called non-glare treatment for irregularly reflecting light.

[Problems to be Solved by the Invention] However, no matter which system is used, the state once set does not change, that is, since the transmittance of video light and the reflectance of external light are constant, for example, a television The brightness, hue, contrast, etc. of the displayed image changes every moment, and the brightness of the room differs between daytime and nighttime. Even if a treated CRT is used, there is a problem that its effects and characteristics cannot be obtained sufficiently effectively.

[Means for Solving the Problems] The present invention has been made in view of such problems, and is an optical filter including a transmission panel mounted on a front surface of a monitor display screen and capable of electrically variably controlling light transmittance. Means, a filter driving means capable of setting and driving the transmittance of the optical filter means based on the brightness of the external light and the light transmittance setting information, and an operation input unit for operating the filter. Constitute.

Further, this optical filter device is located on the front of the display screen to constitute a display device in which an optimal viewing environment is always obtained.

[Operation] For an optical filter means such as a liquid crystal panel in which liquid crystal is sandwiched between two glass panels so that the transmittance can be variably controlled, it is optimal from the light transmittance setting information at that time. If the optical filter means is driven by a signal from the filter drive means and a signal from the operation input unit, which obtains a suitable transmittance drive control signal, the monitor display surface is always controlled to a state where an optimum image is projected. .

Embodiment FIG. 1 shows an embodiment of a monitor device equipped with the optical filter device of the present invention.

1 demodulates R, G, B video signals from the composite video signal via a Y / C processing unit and a matrix circuit unit,
A video processor capable of adjusting the luminance, hue, saturation, etc. of the video signal, 2 is a video drive circuit for driving an electron gun based on the supplied R, G, B video signals, 3 is a CRT It is.

Numeral 4 is an optical filter mounted in close contact with the front of the CRT3, sandwiching a liquid crystal between two glass panels.
In addition, a liquid crystal panel (LCW:
Liquid Crystal Window).

The optical filter 4 formed by a liquid crystal panel is configured as shown in FIG. 2, for example, and the light transmittance is variably controlled from about 6% to 82% by a voltage applied to the transparent electrode 12.

As is well known, light has two orthogonal polarization planes of a P-polarized component (hereinafter, referred to as a P-wave) and an S-polarized component (hereinafter, referred to as an S-wave). As shown in a), for example, only a P wave is transmitted by a polarizing plate 11 and is introduced into a liquid crystal cell 13 in which horizontal and vertical transparent electrodes 12 are arranged in a TN mode transmission type liquid crystal and pixels in a matrix are formed. However, the S wave component is cut off by the polarizing plate 11.

In the liquid crystal cell 13 to which the P-wave is incident, the arrangement state of the liquid crystal molecules 4 changes from the state shown in FIG. 2A to the state shown in FIG. In the case of FIG. 2 (a) where the applied voltage is off, the P wave introduced by the optical rotation of the liquid crystal molecules 14 is twisted by 90 ° and reaches the polarizing plate 15. Since the polarizing plate 15 has the orientation axis direction orthogonal to that of the polarizing plate 1, the light reaching the polarizing plate 5 is transmitted as it is and is output as an S wave. In the case of FIG. 2B where the applied voltage is on, the optical rotation due to the liquid crystal molecules 14 is lost, and the incident P-wave reaches the polarizing plate 15 as it is.
Cut off at 15. That is, the light transmittance can be controlled by the applied voltage. The above is the case of the normally white type, and if the orientation axes of the polarizing plates 11 and 15 are parallel, the normally black type in which light is blocked when the voltage is turned off.

Reference numeral 5 denotes a liquid crystal drive circuit that applies a voltage to the transparent electrode 12 of the optical filter 4, controls the applied voltage level based on a drive control signal from the transmittance setting unit 6, and supplies the voltage to the optical filter 4.

The transmittance setting unit 6 is formed by, for example, a logic circuit,
A drive control signal is generated based on the input various transmittance setting information.

Reference numeral 7 denotes a video signal recognizing unit which samples the video signal demodulated by the RGB in the video processor 1 at a predetermined timing and performs an operation based on the sampled data, for example, a luminance average level and a saturation average for each field. A level, a dominant hue tendency on the image, and the like are calculated, and these calculated data are supplied to a system controller (CPU). The system controller controls the video processor 1 using these data, thereby enabling the so-called AI control (Artifical Intellgent) for setting an optimum drive state for each screen. In this embodiment, the data obtained by the video signal recognition unit 7 is also supplied to the transmittance setting unit 6 as transmittance setting information.

Note that the transmittance setting section 6 and the video signal recognition section 7 may be configured as software means in the system controller.

Reference numeral 8 denotes an external light detection unit which is constituted by, for example, an optical sensor arranged on the surface of the housing of the monitor device, detects the brightness around the monitor device installation position, and sets the data as transmittance setting information as transmittance setting information. Supply to section 6.

Reference numeral 9 denotes an operation unit for allowing a user to manually set the transmittance of the optical filter 4.

In this embodiment, as described above, the image signal recognizing unit 7, the external light detecting unit 8, and the operating unit 9 transmit the light to the transmittance setting unit 6 that controls the liquid crystal driving circuit 5 that drives the liquid crystal of the optical filter 4. The transmittance setting information is supplied, and the operation mode is switched in the transmittance setting unit 6, so that a drive control signal is generated in accordance with each transmittance setting information.

That is, in the operation mode corresponding to the video signal recognition unit 7, for example, the luminance, saturation,
In accordance with information such as the hue, a drive control signal is generated by the optical filter 4 so that the image contrast is in an optimum state, and is supplied to the liquid crystal drive circuit 5. In addition, the external light detection unit 8
In the operation mode corresponding to (1), a drive control signal is generated according to external light, for example, to increase the transmittance of the optical filter 4 when it is bright and to decrease the transmittance when it is dark, and to supply it to the liquid crystal drive circuit 5. Further, the liquid crystal drive circuit 5 is controlled according to a manual operation from the operation unit 7.

For this reason, the optical filter 4 driven by the liquid crystal drive circuit 5 is always set to the optimum transmittance, and is set in a television monitor device in which the screen changes every moment or in an environment where ambient light changes frequently. Even if the present invention is applied to a monitor device, it can sufficiently cope with it.

If a colorant is mixed in the liquid crystal of the optical filter 4 to form a color distribution filter by removing a specific color, the light emission spectrum of the CRT 3 can be controlled to improve color reproducibility. It is possible.

In the present embodiment, the optical filter device and the monitor device are formed integrally, but the optical filter device may be configured to be detachable from the monitor device.

Further, the optical filter portion does not necessarily have to be completely adhered to the CRT surface.

[Effects of the Invention] As described above, in the optical filter device and the display device of the present invention, the transmittance of the optical filter unit is variable based on the output of the external light unit and the supplied light transmittance setting information. As a result, there is an effect that the screen state of the monitor device can always be set to the optimum state, and the average brightness, contrast, etc. (that is, average image quality) of the screen displayed on the display unit can be adjusted on a screen basis. It has an excellent advantage in that it can automatically respond to changes in images and external light because it can be analyzed by a computer.

Further, by arranging such an optical filter device in front of the television receiver, when the periphery of the display device is bright, and when the periphery of the display screen is dark, the brightness adjustment of the display screen is automatically controlled, An optimal viewing environment can always be created.

In addition, since there is an operation input unit for operating the filter, it is possible to respond to a variety of user preferences.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment employing an optical filter device of the present invention, and FIGS. 2 (a) and 2 (b) are explanatory diagrams of the operation of the optical filter. 3 is a CRT, 4 is an optical filter, 5 is a liquid crystal drive circuit, 6 is a transmittance setting unit, 7 is a video signal recognition unit, 8 is an external light detection unit, 9
Indicates an operation unit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G09F 9/00 G09G 3 / 18,3 / 36 H04N 5/72 H01J 29/89

Claims (2)

(57) [Claims] 1. An optical filter capable of electrically variably controlling light transmittance, an operation input unit for operating the filter, and an average brightness, contrast, etc. of a screen displayed on a display unit can be analyzed for each screen. Video signal recognizing means, external light detecting means for detecting the brightness of external light, and a signal from the external light detecting means, a signal from the video signal recognizing means, and a signal from the operation input unit. Transmittance setting means for setting the transmittance of the optical filter, and optical filter driving means for controlling the light transmittance of the optical filter by a signal output from the transmittance setting means, wherein the transmittance setting means A light transmittance of the optical filter is controlled by a signal output from the optical filter. 2. A display device for displaying an image based on an input video signal, an optical filter disposed on a display surface of the display device and capable of electrically variably controlling light transmittance, and operating the filter. An operation input unit, a video signal recognizing unit capable of analyzing an average image quality of an image displayed on the display device on a screen basis, and an external light detecting unit for detecting brightness around the display device, Transmittance setting means for setting the transmittance of the filter based on a signal from the external light detecting means, a signal from the video signal recognizing means, and a signal from the operation input unit; output from the transmittance setting means Optical filter driving means for controlling the light transmittance of the optical filter according to a signal transmitted from the optical filter, wherein the light transmittance of the optical filter corresponds to at least the brightness of the periphery of the display device. A display device controlled by moving means.