JPS6267516A - Multicolor liquid crystal display - Google Patents

Abstract

PURPOSE:To monitor a display part in an optimum state by matching a part corresponding to the prescribed color position of a color filter to the peripheral environment in such a way that a shutter part made of liquid crystal causes said part to do an on or off multifunction. CONSTITUTION:A display pattern dot matrix liquid crystal panel 10 is processed for every picture element unit. A liquid crystal layer 10c is sandwiched with glasses 10d equipped with a picture element electrode 10a and a common elec trode 10b, and said glasses 10d are held by polarization plates 10e so that polari zation axes can intersect orthogonally. At the time of off signal based on a signal from an electrode drive circuit 11, an irradiation light beam 30 from a light source 2 makes incident on one polarization plate 10e, is propagated along a molecule axis, transmitted through the other polarization plate 10e with the plane of polarization rotating by 90 deg.. On the other hand, when an on signal is provided, a liquid crystal molecule changes its array in an electric field direction to lose the optical rotary power and shuts off the irradiation light beam 30. Accordingly the light beam transmitting the liquid crystal panel 10 irradiates the position corresponding to the color filter 4, whereby a target display is made suitable to the peripheral environment so as to be easy-to-see.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a multi-color liquid crystal display, and in particular to a method for turning on and off liquid crystal pixels using illumination light having a spectrum corresponding to the color of a color filter as a backlight.
The present invention relates to a color tod matrix type multicolor liquid crystal display that employs a so-called multicolor one-way system in which color display is performed by turning off the display.

<Prior Art> Prior to explaining the color tod matrix type multicolor liquid crystal display that employs the multicolor one-way system (a system in which color pixels are switched on or off) of the present invention, we will explain the full-color one-way system (a system that switches color pixels on or off). First, we will explain a color tod matrix type liquid crystal display that employs a system that continuously controls pixels from on to off.

Examples of full-color one-sided liquid crystal display technology include ``Commercialized LCD Pocket Color Television'' described in Nikkei Electronics (1984, September, 10) and ``Liquid Crystals and Their Applications J (1984, 10, 18) [ Published by Sangyo Tosho Co., Ltd.] etc. are publicly known.

Figure 2 is a diagram showing the principle of the liquid crystal shutter system used to explain this technology, and Figure 3 (A).

(B) will be explained using a diagram of the principle of a liquid crystal shutter.

In FIG. 2, the liquid crystal shutter section 1 includes a pixel electrode 1a and a liquid crystal illum c which is processed so that the liquid crystal molecules are uniaxially aligned parallel to the plane and twisted by 90'' and has positive dielectric anisotropy. The common electrode 1b is sandwiched between glasses 1d provided thereon, and the glasses 1d are sandwiched between polarizing plates 1e such that the polarization axes are orthogonal to each other.Therefore, the shutter operation of the liquid crystal shutter unit 1 is performed as shown in the principle diagram of FIG. As shown in (A), when no voltage is applied, the light 3 from the light source 2 enters one polarizing plate 1e, propagates along the molecular axis (ICa), rotates the plane of polarization by 90'', and passes through the other polarizing plate. 1e, and as shown in (B), when a voltage higher than the threshold is applied to the liquid crystal 1C, the liquid crystal molecules change their alignment in the direction of the electric field (ICb) and lose light-dispersing properties, so the light incident on one polarizing plate 1e 3 is blocked by the other polarizing plate 1e. From this, the liquid crystal shutter section 1
By continuously varying the applied voltage between zero and the threshold value, the amount of light transmitted can be continuously controlled.

The light 3 that has passed through the liquid crystal shutter 1 irradiates a color filter 4 having three colors of red, green, and blue in this example for each pixel.

In a full-color liquid crystal display having such a configuration, for example, when displaying red (R), the liquid crystal shutter 1 corresponding to the red pixel of the color filter 4 is turned on and the light 3 that falls on this part is transmitted. Other green (G)
The liquid crystal shutter 1 in the portion corresponding to the blue (B) pixel may be turned off to block the light 3 in this portion. Colors other than red, green, and blue are based on the principle of additive mixing (light of two or more colors enters the eye and mixes on the retina to appear as different colors).
displayed by. That is, since the size of each pixel is sufficiently small, if the liquid crystal shutter 1 corresponding to pixels of two or more colors is opened, the colors will be mixed and appear as different colors.

For example, when red and green are mixed, it looks yellow, when blue and green it looks cyan (blue-green), when stomach and red it looks magenta (red-purple), and when LCD shutter 1 corresponding to all is turned on, it looks white. .

Furthermore, these intermediate colors can be obtained by controlling the degree of opening of the liquid crystal shutter 1 by adjusting the voltage applied to the liquid crystal of each portion, and by performing gradation display by subtly changing the mixing ratio. This full-color one-sided LCD display uses a reflective method when it is bright, and a transmissive method using internal lighting when it is dark.The brightness is adjusted to suit dark environments, so when used as a general LCD color TV, the brightness can be controlled. does not require.

On the other hand, in aircraft, ships, etc., for example, it is essential to control the screen brightness of a color liquid crystal display according to the surrounding environment, that is, to control the screen brightness to be bright during the day and dark at night.

Therefore, when using this full-color one-sided liquid crystal display on aircraft or ships, the transmittance of the liquid crystal pixels can be adjusted continuously by adjusting the applied voltage between zero and the threshold value without changing the mixing ratio of the entire liquid crystal shutter. A circuit that changes the opening degree in the same manner may be used. However, such a circuit configuration is complicated and insecure, which increases the probability of failure and inevitably makes it extremely expensive. Moreover, full-color one-sided LCD displays do not require neutral colors, for example, on ships and aircraft, so they are a waste of equipment, which is costly in terms of economics and maintenance of equipment that needs to maintain reliability over a long period of time. There are many problems from this point of view.

Liquid crystal displays used in ships, aircraft, etc. basically only need to be constructed with a limited number of colors (for example, eight colors: red, green, blue, yellow, blue-green, magenta, white, and black). Moreover, it suffices if each pixel is simply turned on/off and controlled. In other words, the circuit configuration of the applied voltage supplied to each liquid crystal does not require intermediate colors unlike the full-color one-sided type, so it only needs to output a value that turns each pixel on or off, and is simpler than the full-color one-sided type. Become something. The principle of this multicolor one-sided liquid crystal shutter method may be the same as that shown in FIGS. 2 and 3.

<Problems to be Solved by the Invention> By the way, when controlling the brightness of the screen according to the surrounding situation in a multi-color liquid crystal display, it is conceivable to control the brightness of a light source used as a backlight.

Incidentally, since a fluorescent lamp that emits white light is generally used as a light source, the brightness of the fluorescent lamp can be controlled by changing the pulse width. However, this method
It is difficult to actually implement this method because the state of the RGB spectrum changes due to weakening of the discharge and the life span is shortened, and the control range is also narrow. Therefore, in practice, it is necessary to provide a complicated circuit that turns on the parts of the liquid crystal shutter that require transparency of the liquid crystal pixels and controls the opening degree of this turning on so that the brightness is optimal, and is therefore extremely expensive. There are also problems from an economic and reliability standpoint, such as the fact that it is inevitable that the device will become a product.

The present invention has been made in view of the problems of the prior art, and uses irradiation light having multiple spectra as a backlight to turn on and off liquid crystal pixels of multiple colors while changing the surrounding environment. An object of the present invention is to provide a multicolor liquid crystal display that can continuously control the brightness of a display panel accordingly.

Means for Solving the Problems> To achieve the above object, the multicolor liquid crystal display of the present invention emits illumination light having a spectrum of a plurality of colors from a light source, and the brightness of this illumination light is controlled by a liquid crystal display. The brightness control section is configured to control according to the surrounding environment, and the shutter section consisting of a liquid crystal is used to turn on or off a portion corresponding to a predetermined color position of a color filter consisting of a plurality of color configurations. Transmitting or blocking the irradiation light,
This device is characterized in that the display section can be monitored in an optimal state according to the surrounding environment.

<Example> Hereinafter, an example of the present invention will be described in detail based on a schematic diagram of a multicolor liquid crystal display of the present invention shown in FIG. still,
In the following drawings, parts that overlap with those in FIGS. 2 and 3 are given the same numbers, and their explanations will be omitted.

In FIG. 1, a plurality of colors (RG,
B) When irradiating light using a light source 20 consisting of a fluorescent lamp emitting a spectrum, e.g. It is composed of a liquid crystal that continuously becomes transparent and darkens to adjust the overall brightness of the irradiated light 30 to match the surrounding environment. A brightness control liquid crystal panel 6, which is a brightness control section, and a color filter 4
For example, in this embodiment, the red (R) part is turned on (however, the applied voltage is off), and the other parts are turned off (however, the applied voltage is turned on in this case) when the irradiation light 30 is turned on. A dot matrix liquid crystal panel 10 for display pattern generation, which is a shutter section made of liquid crystal that transmits and blocks light, is arranged. This dot matrix liquid crystal panel 10 for display pattern generation is made of liquid crystal @fO which is processed in pixel units so that, for example, liquid crystal molecules are uniaxially aligned parallel to the plane and twisted by 90°, and has positive dielectric anisotropy.
Is c the pixel electrode 10a and the common electrode? The glass 10d is sandwiched between two glasses 10d provided with respective Obs, and the glasses 10d are sandwiched between polarizing plates 1e such that their polarization axes are perpendicular to each other.
Or for example, an on signal (when a voltage above the threshold is applied)
When the signal is off, the irradiated light 30 from the light source 2 enters one polarizing plate 10e, propagates along the molecular axis, rotates the plane of polarization by 90 degrees, and passes through the other polarizing plate 10e. On the other hand, when there is an on signal, the liquid crystal molecules change their alignment in the direction of the electric field, lose their travel properties, and block the irradiation light 3. Therefore, the dot matrix liquid crystal panel 10 for display pattern generation
The light that has passed through irradiates the corresponding position of the color filter 4, which consists of a large number of grid-like three primary colors of red, green, and stomach in this example, for each pixel, thereby displaying the desired display on the surrounding environment. You can make it easier to see.

That is, by adopting such a configuration, for example, when the surroundings are bright, such as during the day, the brightness control liquid crystal panel 6 becomes transparent, and the brightness of the irradiated light 3 is increased relative to when the surroundings are dark (
For example, in this case, the control signal from the brightness control circuit 60 is turned off) to transmit 100% of the irradiated light 30, and the color is displayed in a bright transparent state based on the on/off operation of the dot matrix liquid crystal panel 10 for display pattern generation. A predetermined position of the filter 4 is irradiated to display a display that is not absorbed by the surrounding environment, and when the surrounding area becomes dark such as at night, the brightness is set on the brightness control liquid crystal panel 6 according to the degree of brightness, contrary to the above. By applying a control signal from the control circuit 60, the brightness of the irradiated light 30 is lowered relative to daytime brightness, and a relatively dark transmission state is achieved based on the on/off operation of the dot matrix liquid crystal panel 10 for display pattern generation. By illuminating a predetermined position of the color filter 4, it is possible to display an image that is easy to see and adapts to the surrounding environment.

Incidentally, in the present invention, the brightness control liquid crystal panel G shown in FIG. 1 is not limited to being configured as an independent panel. The point is that the brightness of the irradiated light 3 from the light source 20 can be controlled in accordance with the surrounding environment, so for example, the brightness control liquid crystal and the display pattern generating dot matrix liquid crystal may be formed into an integrated panel shape. In other words,
A specific example of the structure is ``Polarizing plate - Glass - Liquid crystal for dot matrix display -'' which has polarizing plates arranged on the top and bottom, and a liquid crystal for dot matrix display, a liquid crystal for brightness control, and glass arranged in the middle.
It consists of a panel configuration of glass - liquid crystal for brightness control - glass - polarizing plate. Even if this is done, the main structure of the present invention does not change in any way.

Furthermore, the positions of the color filters are not limited to those shown in FIG. 1 as well. For example, the above-mentioned liquid crystal for brightness control and dot matrix liquid crystal for display pattern generation may be integrated into an integrated panel, or the
It may also be incorporated into a dot matrix liquid crystal panel for generating display patterns as shown in the figure. However, if the color filters are placed on the surface as shown in FIG. 1, the structure is more suitable for displaying images that are not affected by the surrounding environment as intended by the present invention.

Furthermore, in the present invention, the color filter is not limited to three primary colors, but may be configured as a combination of red and green, red and blue, blue and green, etc., depending on the purpose.

By the way, the present invention is not limited to applications such as ships and aircraft, but can be applied to a wide variety of structures and functions that require similar requirements.

<Effects of the Invention> As described above in detail with reference to the embodiments, the multicolor liquid crystal display of the present invention is suitable for use when installed in devices that require brightness control in accordance with the surrounding environment. Continuously variable brightness control with a simple configuration eliminates the need to connect complicated and expensive circuits to the liquid crystal shutter to control brightness, or to control the brightness of the light source, as in conventional full-color liquid crystal displays. This can be achieved at low cost and with high reliability. It is predicted that multi-color liquid crystal displays will be used in large numbers in aircraft, etc. In such cases, the multi-color liquid crystal display of the present invention has a simple structure and can be provided at low cost, so it will be effective. There is something big about it.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a multicolor liquid crystal display according to the present invention, FIG. 2 is a diagram of the principle of a conventional liquid crystal shutter system, and FIG. 3 is a diagram of the principle of a liquid crystal shutter. 1...Liquid crystal shutter section, 2, 20...Light source, 4...
・Color filter, 6...LCD panel for brightness control, 1
0...Dot matrix liquid crystal panel for display pattern generation.

Claims (1)

[Claims] A color liquid crystal display that displays a desired color by comprising a liquid crystal, a color filter having a plurality of colors, and a light source that irradiates the liquid crystal and the color filter with light having a spectrum of a plurality of colors. A brightness control section, which is provided in front of the light source and is composed of a liquid crystal that controls the brightness of the irradiated light, and a portion of the color filter corresponding to a predetermined color position are turned on or off in multiple ways to control the irradiated light. A multi-color liquid crystal display characterized by comprising a shutter section made of liquid crystal that transmits or blocks light.