KR830001003B1 - Self-luminous light source for LCD clock - Google Patents

Abstract

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Description

Self-luminous light source for LCD clock

1 is a cross-sectional view showing the overall configuration of a display device for a liquid crystal watch using the self-luminous light source according to the present invention.

2 is a cross-sectional view showing a specific configuration of the spontaneous light source 7 of FIG.

FIG. 3A is a plan view showing the phosphor layer 8 of FIG.

FIG. 3 (b) is a plan view of the upper axis glass plate 3 for explaining the correspondence relationship between the phosphor layer 8 and the liquid crystal display surface shown in FIG.

The present invention relates to a self-luminous light source that enables night display of a liquid crystal clock.

The conventional field effect type liquid crystal display element reflects external light with a reflecting plate, and displays a character pattern. As a result, the display function is lost in the dark at night.

In order to overcome such drawbacks, the lower face of the liquid crystal display element, tritium ⁽³ H) by a plurality of array with a fluorescence material which self-luminous inner tube coated with a, and at the same time an inner wall enclosing the gas, enabling the display of the night One liquid crystal clock has been proposed and is already known.

However, the technique of encapsulating tritium gas into a tub is extremely difficult (see US Pat. No. 3,817,733), although it is effectively encapsulated and sealed, there is a risk of leakage and radioactive contamination over time. In addition, since several tubes are arranged, the luminance of the boundary portions of each other decreases, and as a whole becomes a light source with an unbalanced luminance, a transmissive light scattering body must be placed on the tube, resulting in a thick self-emitting source.

In order to overcome this drawback, it is conceivable to adapt the prome gap ¹⁴⁷ P _m to the self-luminous fluorescence material which is relatively easy to fabricate and which does not have a risk of leakage because it is solid. However, ¹⁴⁷ P _m emits a high energy β-ray of 220 Kev, and braking X-rays are generated when a substance absorbing it is produced, and it may be accompanied by a danger when used on a human body like a liquid crystal watch.

It is therefore an object of the present invention to provide a self-luminous light source for a liquid crystal watch having a safe and uniform luminance, which improves the above-mentioned drawback of ¹⁴⁷ P _m .

In order to achieve the above object, in the present invention, a phosphor layer having light reflectivity and containing at least a portion of the radioactive element promedim ( ¹⁴⁷ P _m ), and on one side of the phosphor layer, is separated from the phosphor layer. A reflection layer for reflecting and scattering the fluorescence of the light emitting layer; a case for shielding braking X-rays generated due to β-rays generated from the promethium; and a case opposite to the reflection layer of the phosphor layer. On the axis and on the axis opposite to the phosphor layer of the first cover for absorbing β-rays generated by the promethium and transmitting light from the phosphor layer, and on the promethium For the liquid crystal watch by a second cover for shielding the braking X-rays caused by the β-rays and transmitting the light from the phosphor layer. A self-luminous light source is constructed.

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

FIG. 1 shows a cross section of a display element for a liquid crystal watch constructed by using a self-luminous light source according to the present invention. In FIG. 1, (1) is a display element for liquid crystal clocks, (2) is an up-axis polarizing plate, (3) is an up-axis glass plate, and the transparent conductive whole country corresponding to the number or letter which should be displayed is deposited on the lower surface. . (4) is a nematic liquid crystal material layer, (5) is a lower axis glass plate, The transparent conductive electrode corresponding to the transparent conductive electrode installed in the upper axis glass plate 3 is installed in the upper surface. (6) is a lower polarizing plate, and is arrange | positioned so that a polarization direction may orthogonally cross with the upper axis polarizing plate 2 and the lower polarizing plate 6, respectively. (7) is a self-luminous light source according to the present invention, the details of which are shown in FIG.

The method of claim 2, 8 are made by a conventional printing process is applied to the self-luminous phosphor plate to the ¹⁴⁷ P _m with the radiation source. (9) is a white reflector for reflecting and scattering fluorescence emitted by? -Rays, and barium sulfate (B _a SO ₄ ) is recommended for this. This is because B _a SO ₄ not only exhibits high light reflectance from visible light to ultraviolet light and has diffuse reflection characteristics close to the highest state, but is also a stable material that is hardly deteriorated even in close contact with fluorescent materials. Reference numeral 10 denotes a transparent polymer thin film, which is responsible for absorbing β-rays. Reference numeral 11 denotes a substrate of the reflector 9 and a braking X-ray generated when β-rays are absorbed into the material (the absorption is a self-luminous phosphor plate 8, a reflector 9, a transparent polymer thin film 10, etc.). A thin metal case is recommended for this purpose, in which aluminum foil is recommended. (12) is a transparent glass plate for absorbing the braking X-rays and at the same time acting as the reflector, and lead glass having a particularly high content of Pb so as to absorb braking X-rays even if thin is sufficient. . In addition, the use of acrylic resin containing Pb is appropriate because it absorbs β-rays and brake X-rays. At this point, there is no technology for increasing Pb concentration as much as lead glass. It is feed.

FIG. 3 (a) is a plan view of the self-luminescent phosphor flat plate 8 shown in FIG. Reference numeral 14 _denotes a surface coated with a fluorescent material (Z _n S: Cu), and reference numeral 13 denotes a portion of promium oxide (P _{m 2} O ₃ ) covering a portion of the fluorescent material (Z _n S: Cu) coated surface 14. It is an application surface. As shown in FIG. 3 (a), the upper axis glass plate 3 (as shown in FIG. 3 (b)) shows that the promethium oxide is the time display portion of the liquid crystal clock (12:46 in the example shown in FIG. It is apply | coated only to the area | region corresponded to minute).

Since the self-luminous light source according to the present invention adopts the above-described configuration, in the daytime where the external light is bright, the self-luminous phosphor plate functions as a simple light reflector without acting as a light source and at night serves as a surface light source.

Because and ₁₄₇ P _m self-luminous phosphor plate is composed of a flat plate shape, ³ H inclusion character does not show an imbalance of the brightness, such as when used to arrange the light-emitting fluorescent tube probe, Moreover, a transmission type light scattering member for removing an imbalance of the brightness, etc. No extra device is required. For this reason, the thickness of the whole light source also becomes thin, and it becomes suitable as a self-luminous fluorescent substance plate for wristwatches. In addition to be a coated printing it enables since the flat plate-like, large quantities are suitable for the production, and ¹⁴⁷ P _m is fluorescence material as an oxide of the solid-state: and, so to cover the particle surface of (Z _n S Cu), although may be damaged ³ H gas It does not spread outside and cause radioactive contamination.

In addition, braking X-rays from polymer films, fluorescent materials, and white reflectors that absorb high-energy β-rays are absorbed by lead glass and metal cases to prevent X-ray emission to the outside. It does not pose any danger when used in an appliance. Moreover, even if the self-luminous light source unit is transported or assembled to a watch, not only the β-rays but also the braking X-rays are protected by the element unit, the machine assembly company can safely handle them.

Moreover, as shown in FIG. 3 (a) and FIG. 3 (b), without showing a self-luminous paint on the entire surface of the self-luminous phosphor flat plate 8, it shows "hour", "hour", and "minute". The portion 14 which is applied only to the number display portion 13 and displays other portions, for example, "date", "am, afternoon" and "second", is further made of the same material as the time display portion 13, ¹⁴⁷ A conventional fluorescent material containing no P _m is applied. With such a configuration, even if a high concentration of ¹⁴⁷ P _m is placed in the time display portion 13, the radioactive intensity as the entire self-luminescent phosphor flat plate 8 remains within the regulation value, and furthermore, the luminance of the time display portion 13 is improved. The contrast of visual display improves. In addition, since the same reflective material is applied to the time display portion 13 and the other portion 14, it becomes a reflecting plate having a uniform reflectance throughout the daytime, resulting in high display quality at night and during the daytime.

Claims (1)

A liquid crystal having a light reflecting property, a phosphor layer containing at least a portion of the radioactive element promethium ( ¹⁴⁷ P _m ), and a reflecting layer on one side of the phosphor layer for reflecting and scattering fluorescence from the phosphor layer; A self-luminous light source for a watch comprising: a case for shielding braking X-rays caused by β-rays generated by the promethium, and a side opposite to the reflective layer of the phosphor layer, on a side opposite to the phosphor layer of the reflective layer. A first cover for absorbing β-rays generated at and transmitting light from the phosphor layer, and is now due to the β-rays generated at the promethium on the opposite axis of the phosphor layer of the first cover And a second cover for shielding the braking X-rays and transmitting light from the phosphor layer. A self-luminous light source.

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