JPH02178627A - Illuminator - Google Patents

Abstract

PURPOSE:To achieve the illumination of various tones by providing a transmissive reflecting plate where a transparent film substrate has a light shielding part and colorant is added to transparent parts except the light shielding part. CONSTITUTION:The transparent film substrate 12 added with colorant is used as the transmissive reflecting plate 11 arranged longitudinally in parallel to a three-wavelength white, cold cathode tube 10. Since light made incident on the transmissive reflecting plate 11 is intense in the vicinity of the cold cathode tube 10, the light shielding part 13 is printed or etched in a part in the vicinity of the tube 10. The transmittance of the entire visible ray area drops by passing the light through the colored, transmissive reflecting plate 11; however, the spectral intensity of the same color as the plate 11 is increased, and the hue of white can have gradation. This easily and inexpensively achieves the illumination of various tones whose key tone is white, and a liquid crystal device of various tones can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to personal computers and office related art The structure of a transmissive monochrome liquid crystal display panel will be explained using FIG. In the figure, 1 is a cold cathode tube, which is a three-wavelength white light source. Since the light emitted from the cold cathode tube 1 is strong near the cold cathode tube 1, unevenness occurs in the light incident on the liquid crystal display panel.

In order to average this and make the light uniform, a light-transmitting reflector plate 2 and a diffuser plate 6 are used in which a light-shielding portion 4 is formed on a transparent film substrate 3 by printing or etching. 6 is a polarizer,
Linearly polarizes light in the direction of the arrow. 7 is a display cell, in which a liquid crystal with a molecular alignment with a left-handed twist angle of 240° is sealed between two transparent substrates, and a transparent electrode is formed on the substrate, and a voltage is applied to the electrode. This allows a predetermined display to be performed.

The light that has passed through the display self is emitted as elliptically polarized light due to the birefringence effect when no voltage is applied, and d/Δn when a voltage is applied.
becomes smaller and is emitted as linearly polarized light. Here, d indicates the thickness of the display cell, and Δn indicates the birefringence index. 8 is a compensation cell,
It uses the same liquid crystal as the display self, but the orientation direction is reverse twisted, 240 degrees to the right. The phase difference of the incident elliptically polarized light when no voltage is applied is returned to zero by the compensation cell 8 having an orientation direction of reverse twist, and becomes linearly polarized light. This linearly polarized light further reaches the analyzer 9, but since it is installed in a crossed nicol state, it is cut and becomes black. On the other hand, when a voltage is applied, the incident linearly polarized light loses the compensation relationship by the compensation cell 8, and a phase difference occurs on the output side, resulting in an elliptically polarized state.

This phase difference is preferably circularly polarized light close to π/4, and can almost be achieved by making the product of d and Δn as small as possible. When this circularly polarized light is detected by the detector 9, a white state is obtained.

This transmissive monochrome liquid crystal display panel is used in combination with a drive circuit as a transmissive monochrome mode liquid crystal device.

Problems to be Solved by the Invention This conventional structure has the following problems. FIG. 4 shows an emission spectrum curve of the three-wavelength white cold cathode tube 1, and the hue of the white color varies depending on the spectral intensity ratio of the three primary colors (red, blue, and green). Nowadays, the influence of a single display panel on the eyes cannot be ignored, and the requirements for color hues are diversifying, so this is a method of changing the color tone of white.

There are methods such as changing the light source or adding dye to the liquid crystal material, but either method is expensive and economically unfavorable.

In view of the above-mentioned points, the present invention aims to provide a lighting device capable of illuminating in various colors.

The film substrate has a light-shielding part, and a light-transmitting reflective plate is added to transparent parts other than the light-shielding part with a coloring agent added thereto.

Effect: By using the above-mentioned illumination device, it is possible to obtain a transmission type liquid crystal display with various shades based on white at low cost.

Embodiment FIG. 1 is a perspective view of a cold cathode tube and a translucent reflector. Light is emitted from the three-wavelength white cold cathode tube 10 in the direction of the arrow. The translucent reflecting plate 11 arranged parallel to the longitudinal direction of the cold cathode tube 10 is made of a transparent film substrate 12 to which a coloring agent is added.

Since the light incident on the translucent reflecting plate 11 is strong near the cold cathode tube 10, a second light shielding portion 163 is printed or etched in the vicinity of the cold cathode tube 1o. - When light passes through this colored translucent reflective plate 11,
Although the transmittance of the entire visible light region decreases, the spectral intensity of the same color as the colored color increases, making it possible to vary the hue of white. FIG. 2 shows a spectral characteristic curve of light emitted from a liquid crystal display device when a green-colored translucent reflecting plate 11 is used, and the vertical axis represents the transmittance.

When the translucent reflector is colored, the slope of the curve near the wavelength corresponding to green is larger than when it is not colored.In other words, due to the coloring, green becomes relatively stronger compared to other colors. It can be said that there are.

According to the embodiments described above, it is possible to inexpensively and easily color a transmissive monochrome liquid crystal display panel, and display with five different tones can be achieved.

Effects of the Invention As described above, according to the present invention, it is possible to inexpensively and easily provide illumination with various tones based on white, and it is possible to realize a liquid crystal display device with various tones.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the main parts of an embodiment of the present invention, Figure 2 is a transmittance curve diagram of a liquid crystal display device using a green light-transmitting reflector, and Figure 3 is a transmissive black and white liquid crystal display. FIG. 4 is a configuration diagram showing the configuration of the display panel, and is an emission spectrum curve diagram of a three-wavelength white cold cathode tube. 10... cold cathode tube, 11... translucent reflector, 12... transparent film substrate, 13...
...shading part. Name of agent: Patent attorney Shigetaka Awano and one other person (n1711)

Claims (1)

[Claims] A lighting device that includes a light-transmitting reflector that has a light-shielding part on a transparent film substrate and a coloring agent added to the transparent parts other than the light-shielding part.