JPH068621Y2 - Color display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention utilizes a display device such as a fluorescent display tube (hereinafter abbreviated as VFD) that displays characters, figures, etc. by band-shaped spectrum light, and uses red. The present invention relates to a color display device that performs color display with a specific color such as white and the like.

[Conventional technology]

Due to the clear color contrast and good visibility, red light,
2. Description of the Related Art Color display devices have been put into practical use that display characters, figures, and the like using light of a specific color such as green light and white light.

The VFD, EL, etc., which are self-luminous display devices that can obtain a clear display and can be thinned, have been colorized by various methods.

In VFD, the following display devices are known, and such display devices are known in the field of liquid crystals.

A red (R), green (G), blue (B) phosphor such as (Zn, Cd) S: Ag, Cl is deposited to form a matrix electrode for graphics. The red display section illuminates only the red phosphor, and the white display section emits all R, G, B phosphors.

Zn which emits band spectrum light as shown in FIG.
V: Vd using O: Zn, neutral polarizing plate, R,
A color display device in which three color polarizing plates for G and B and two TN liquid crystal cells arranged between the color polarizing plates are laminated. V
Color display is performed by synchronizing the display operation of characters and figures by the FD with the ON / OFF operation of the TN liquid crystal cell.

A color display device in which a VFD using ZnO: Zn is provided with red, green, and blue filters according to a phosphor pattern.

A color display device in which a guest-host (GH) liquid crystal containing a colored dye in a liquid crystal, a neutral polarizing plate, a liquid crystal cell for displaying characters and figures, and a white light source are combined.

[Problems to be solved by the device]

Each of the above display devices has the following problems (1) to (4).

According to the display device of (1), the color phosphor capable of obtaining relatively high brightness is the sulfide phosphor as described above, and the gas generated from these causes the filament to deteriorate and the display life to be short.

(2) is an improvement of the drawbacks of the display device of,
Although it is possible to extend the life and display with a specific color and white, the display quality is likely to deteriorate due to unevenness, peeling, etc. of the adhered portion of the color polarizing plate. It also requires a large number of components and is expensive. Further, the TN liquid crystal has a drawback that the viewing angle is narrow.

In the display device of (3), fine processing and alignment of the filter are complicated and difficult.

(4) As shown by the curve 8 in FIG. 4, the GH liquid crystal has a gentle drooping characteristic and poor color purity. In addition to the liquid crystal cell for displaying characters and the like, a white light source is required, which is expensive.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a color display device capable of performing color display with a high-purity specific color and white with a simple structure.

[Means for Solving the Problems]

The color display device of the present invention comprises a display unit which emits a band-shaped spectrum light having a peak in a specific wavelength region, a filter having a light transmittance in the specific wavelength region smaller than that in other regions, and a light transmittance of the filter. A guest-host liquid crystal cell that transmits light including light in a region having a low ratio, and a display unit and a driving unit that drives the liquid crystal cell are provided.

[Action]

Since a filter having a relatively small transmissivity in the specific wavelength region is combined with a display unit that emits band-shaped spectrum light having a peak in the specific wavelength region, the guest-host liquid crystal cell is turned on to substantially A white output light can be obtained. When the guest-host liquid crystal cell is turned off, output light of a specific color with high color purity can be obtained.

〔Example〕

An embodiment of the present invention will be described with reference to FIG. In the figure, 101 is a VFD as a display unit that uses ZnO: Zn as a phosphor and graphically displays figures and the like 102
Is a neutral polarizing plate. Reference numeral 103 denotes a guest-host liquid crystal cell (hereinafter, abbreviated as GH liquid crystal cell or GH) in which a nematic liquid crystal and a red dye are enclosed between two glass substrates having transparent electrodes adhered to the entire inner surface. , GH is off, the absorption axis of the dye is in the same direction as the polarization axis of the neutral polarizing plate 102. 104 is the second
As shown in FIG. 6B, the filter has a complementary color relationship with the spectral emission intensity of ZnO: Zn and has a low light transmittance in the green region. This filter 104 has a sharp fall characteristic.
A display drive circuit 106 is connected to the VFD, a liquid crystal drive circuit 105 is connected to the GH, and both drive circuits 105 and 106 have a common timing control circuit 10.
7 is connected and driven synchronously. Fourth
The figure shows the spectral transmittance characteristics of the GH 103 and the filter 104 of FIG. As shown in FIG. 4, when the GH liquid crystal cell is turned on without inserting the filter 104, the curve 5
As described above, the transmittance slightly decreases in the green to blue region. When the filter 104 is inserted in this state, the transmittance in the green region is lowered, and the characteristic shown by the curve 6 is obtained. Next, when the GH liquid crystal cell is turned off with the filter 104 inserted, the transmittance in the green to blue region is greatly reduced as shown by the curve 7. If there is no filter 104 here, GH
The transmittance of the liquid crystal cell is as shown by curve 8, but GH103
Since the light component having a shorter wavelength is cut by the filter 104 having a steeper falling characteristic, the purity of the obtained red light becomes higher as shown by the curve 7.

Next, the operation of the configuration shown in FIG. 1 will be described.

i) White display The display drive circuit 106 drives the VFD 101 to display characters and figures. The output light when the GH 103 is on and the filter 104 is not inserted has a green color as shown by the curve 1 in FIG. 3, is polarized by the neutral polarizing plate 102, and is shown by the curve 2 in FIG. By passing through the filter 104, the green component is suppressed,
It becomes almost white light visually.

ii) Red display When the GH 103 is turned off by the liquid crystal drive circuit 105, the output light of the filter 104 passes only the red component by the GH 103, as shown by the curve 3 in FIG. If the filter 104 is not provided, the output light of the GH 103 is as shown by the curve 4 in FIG. 3, but the light component having a wavelength shorter than red is cut by the filter 104 having a steep falling characteristic. As shown by the curve 3 in the figure, the characters and figures are displayed in red light with high purity. By synchronizing the liquid crystal drive circuit 105 and the display drive circuit 106 by the timing control circuit 107, desired red color display and white color display can be obtained. Further, if the timing control circuit 107 is removed and the liquid crystal drive circuit drives the GH 103 off in response to a caution signal or the like indicating some abnormal state, a red display that calls attention such as a warning becomes possible.

In the embodiment described above, the magenta filter and the red GH, which have a low light transmittance in the green region and a sharp falling characteristic in the red region, are used, but the peak wavelength of a light source (display unit) having a continuous spectrum is used. Therefore, filters with different characteristics can be used at appropriate times. Further, by using a magenta filter having a sharp fall characteristic in the vicinity of blue and a blue GH, it is possible to perform color display in blue and white with high color purity.

[Effect of device]

According to the color display device of the present invention, there is an effect that it is possible to perform color display with a clear specific color and substantially white with a simple structure.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 (a) is an intensity distribution diagram of band spectrum light emitted from the phosphor ZnO: Zn, and FIG. 2 (b) is a filter of the embodiment. FIG. 3 is a graph showing the spectral transmittance characteristics of the output light, FIG. 3 is a graph showing the spectral emission intensity of the output light in each case where the presence or absence of a filter and the ON / OFF of the GH are combined in one embodiment, and FIG. 4 is the GH and the filter. It is a figure which shows the spectral transmittance of. 101 ... Fluorescent display tube (VFD) as a display unit, 103 ... Guest-host liquid crystal cell (GH liquid crystal cell, G
H), 104 ... Filter.

Claims (1)

[Scope of utility model registration request] 1. A display unit that emits band-shaped spectrum light having a peak in a specific wavelength region, a filter having a smaller light transmittance in the specific wavelength region than other regions, and a small light transmittance in the filter. A color display device comprising a guest-host liquid crystal cell that transmits light including light in a region, and a display unit and a drive unit that drives the liquid crystal cell.