JP2001067030A - Surface light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface light emitting device capable of displaying not only a mere static image but also a dynamic image, and allowing expansion of a utilization range. SOLUTION: This surface light emitting device comprises a first ultraviolet emission lamp 4 emitting ultraviolet rays in the UV-A wavelength range; a second ultraviolet emission lamp 5 emitting ultraviolet rays in the UV-C wavelength range; and a fluorescence plate 3 having both a phosphor emitting light by irradiation of the ultraviolet rays in the first wavelength range and a phosphor emitting light by irradiation of the ultraviolet rays in the second wavelength range. By singly or simultaneously lighting the two ultraviolet emission lamps 4, 5, plural kinds of fluorescence by the two phosphors can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface light-emitting device capable of performing color display using an ultraviolet radiation lamp, and more particularly to a surface light-emitting device capable of exhibiting a plurality of display modes on one light-emitting surface. It is about.

[0002]

2. Description of the Related Art Conventionally, as means for performing color display by emitting light from a phosphor, a display is formed by using a special phosphor which emits light by irradiating an ultraviolet ray on a wall or the like as decoration of a store or the like. 2. Description of the Related Art A display body emits light by radiating ultraviolet rays from an ultraviolet radiation lamp called a black light. This display has a specific wavelength (mainly 36
0 nm), when an image is drawn on a white background using a printing method or the like in which three primary color phosphors that emit light by irradiation with ultraviolet light are separated into respective primary colors, this image remains white under visible light, An ultraviolet ray lamp is turned on by blocking visible light from the image drawn by the phosphor, and the specific wavelength (mainly 365)
nm) By irradiating ultraviolet rays, a bright color light is emitted in the dark to display an appropriate image.

[0003]

In the above-described color display by emitting light from a phosphor using an ultraviolet radiation lamp, a preferable display with vivid and fantastic colors can be obtained, but the display can be performed only in darkness with little visible light. Since the display effect is not exhibited, the range of use is limited, for example, outdoors at night or in a dark room, and there is no movement in the display, which may result in a monotonous display.

Accordingly, an object of the present invention is to provide a surface light emitting device capable of not only a mere still image but also a dynamic image and expanding the range of use.

[0005]

In order to achieve the above object, a surface light emitting device according to the present invention comprises a first ultraviolet light emitting lamp for emitting ultraviolet light in a first wavelength range, and a wavelength of the first ultraviolet light emitting lamp. A second ultraviolet radiation lamp that emits ultraviolet light in a second wavelength range different from the wavelength range, a phosphor that emits light when irradiated with ultraviolet light in the first wavelength range, and a light that emits light when irradiated with ultraviolet light in the second wavelength range And a fluorescent material that emits light when irradiated with ultraviolet light in the first wavelength range by turning on the two ultraviolet radiation lamps individually or simultaneously. It is characterized in that a plurality of types of fluorescent light emission are performed by a fluorescent material that emits light when irradiated with ultraviolet light in two wavelength ranges.

The first wavelength range is a UV-A wavelength range centered at approximately 365 nm, and the second wavelength range is a UV-C wavelength range centered at approximately 254 nm. .

[0007] The present invention is characterized in that a fluorescent luminous body and two kinds of ultraviolet radiation lamps are arranged in a liquid crystal cell and used as a backlight of a liquid crystal display device.

[0008]

FIG. 1 shows an embodiment in which the surface emitting device of the present invention is disposed on the back surface of a liquid crystal cell and is used as a backlight of a liquid crystal display device. In the figure, reference numeral 1 denotes a sidelight type liquid crystal display device, 2 denotes a liquid crystal cell for displaying by liquid crystal, and 3 denotes a liquid crystal cell 2 in the liquid crystal display device 1.
And a fluorescent light emitting plate 4 formed by forming a display such as an image by printing or the like on a sheet using a phosphor described later, and 4 is disposed on a side portion in the liquid crystal display device 1. , Approximately 36
A first ultraviolet radiation lamp for irradiating ultraviolet rays in a UV-A wavelength region centered on 5 nm; a second ultraviolet radiation lamp for irradiating ultraviolet light in a UV-C wavelength region centered on approximately 254 nm; A reflecting plate 7 for reflecting ultraviolet light toward the display surface of the liquid crystal display device 1 is a driving means capable of driving the first ultraviolet radiation lamp 4 and the second ultraviolet radiation lamp 5 individually or simultaneously to turn on and off. is there.

The fluorescent light-emitting plate 3 corresponds to a diffusion plate for diffusing light from a light source in a conventional liquid crystal display device. For example, one surface of a transparent or translucent synthetic resin sheet is provided with a UV-A wavelength. An appropriate image is formed by printing (silk screen printing) or the like using a phosphor that emits light when irradiated with ultraviolet light in the region and a phosphor that emits light when irradiated with ultraviolet light in the UV-C wavelength region. In addition, an image formed by a phosphor for the UV-A wavelength range is formed on one side of the sheet body, and an image formed by a phosphor for the UV-C wavelength range is formed on the other side. For example, means such as embedding may be used.

[0010] More specifically, U at about 365 nm is the center.
The image is drawn by separating the three primary color phosphors, which emit light when irradiated with ultraviolet rays in the VA wavelength range, into primary colors, and further emits light from above by irradiation with ultraviolet rays in the UV-C wavelength range centered at approximately 254 nm. The three primary color phosphors are separated into respective primary colors to draw an image.

As a material to be used as the three kinds of phosphors that emit light by irradiation with ultraviolet rays in the UV-A wavelength range, for example, YVO ₄ : Eu is used as a red phosphor. Y ₂ O ₂ S: E
u. ZnS: Mn. (Zn, Ca) S: Cu and the like are used, and these are used as one kind or as a mixture of two or more kinds. As the green phosphor, for example, ZuS: C
u, Al. (Zn, Cd) S: Cu, Al. ZuS: C
u, Au, Al. (Zn, Cd) S: Cu. ZuS: C
u. Zn ₂ GeO ₄ : Mn. CeMgAl ₁₁ O ₁₉ : Tb.
SrGa ₂ S ₄ : Eu ²⁺ . LaOBr: Tb, Tm. La
₂ O ₂ S: Tb and the like, and these are used alone or as a mixture of two or more. Further, the blue phosphor is ZnS: Ag. CaWO ₄ . ZnS: Ag, G
a, Cl. Ca ₂ B ₅ O ₉ Cl: Eu ²⁺ . BaMgAl ₁₄
O ₂₃ : Eu ^{2+ and the} like, and these are used as one kind or as a mixture of two or more kinds. By appropriately selecting and mixing these phosphors, it is possible to form an image that emits full color light.

Similarly, for irradiation of ultraviolet rays in the UV-C wavelength range.
Materials used as three kinds of phosphors that emit more light include:
As a red phosphor, Y_TwoO_Three: Eu. (Y, Gd) B
O_Three: Eu and the like, and one or more of these
Used as a mixture of Also, as a green phosphor
Is Zn_TwoSiO_Four: Mn. Y_ThreeAl_FiveO₁₂: Tb. Gd _Two
O_TwoS: Tb. LaPO_Four: Ce, Tb, etc.
These are used as one kind or as a mixture of two or more kinds.
Further, as the blue phosphor, (Sr, Ca) B_FourO₇:
Eu. Y_TwoSiO_Five: Ce and the like, and only one of these
Or a mixture of two or more.

In the surface light emitting device of the present invention having the above-described structure, when the ultraviolet light emitting lamp is turned off, the phosphor on which the image is drawn remains ground white, When the means 7 turns on the first ultraviolet radiation lamp 4 and irradiates the fluorescent light emitting plate 3 with ultraviolet light having a UV-A wavelength region centered at approximately 365 nm, the UV-A wavelength region formed on the fluorescent light emitting plate 3 is irradiated. The three primary color phosphors, which emit light when irradiated with ultraviolet light, emit light to perform full-color fluorescent display.
At this time, the three primary color phosphors that emit light by irradiation with ultraviolet rays in the UV-C wavelength range do not emit light and remain ground white.

Next, when the driving means 7 turns on the second ultraviolet radiation lamp 5 and irradiates the fluorescent light emitting plate 3 with ultraviolet light in the UV-C wavelength region centered at approximately 254 nm, the fluorescent light emitting plate 3 is formed. The three primary color phosphors that emit light when irradiated with ultraviolet light in the UV-C wavelength range emit light to perform full-color fluorescent light emission display different from the above-described fluorescent light emission. At this time, UV-A
The three primary color phosphors that emit light when irradiated with ultraviolet light in the wavelength range do not emit light and remain ground white.

Further, the driving means 7 simultaneously turns on the first ultraviolet radiation lamp 4 and the second ultraviolet radiation lamp 5,
Ultraviolet light in the UV-A wavelength range and UV-C for the fluorescent light emitting plate 3
When ultraviolet light in the wavelength range is irradiated, an image that emits light in ultraviolet light in the UV-A wavelength range and an image that emits light in ultraviolet light in the UV-C wavelength range simultaneously perform full-color fluorescent display. Thereby, in the surface emitting device of the present invention, (1) both the first ultraviolet radiation lamp 4 and the second ultraviolet radiation lamp 5 are turned off, (2) only the first ultraviolet radiation lamp 4 is turned on,
(3) Only the second ultraviolet radiation lamp 5 is turned on, (4) First
And the second ultraviolet radiation lamp 5 is turned on.

In the above-described embodiment, the case where the backlight is used as a backlight of a liquid crystal display device has been described. However, it is needless to say that the backlight may be used for other purposes. UV-centered around 365 nm
The A wavelength range and the UV-C wavelength range centered at approximately 254 nm have been described, but the present invention is not limited to this, and can be set appropriately.

[0017]

As described above in detail, according to the present invention, the first ultraviolet radiation lamp which emits ultraviolet light of the first wavelength range and the second ultraviolet light range different from the wavelength range of the first ultraviolet radiation lamp. A second ultraviolet radiation lamp that emits ultraviolet light in a wavelength range,
By comprising a fluorescent material that has both a phosphor that emits light when irradiated with ultraviolet light in the first wavelength range and a fluorescent material that emits light when irradiated with ultraviolet light in the second wavelength range, (1) 1
(2) Only the first ultraviolet radiation lamp is turned on, (3) Only the first ultraviolet radiation lamp is turned off, and (3)
Only the second ultraviolet radiation lamp is lit, and (4) the first ultraviolet radiation lamp and the second ultraviolet radiant lamp are both lit, so that a display combining four patterns can be performed. It is also possible to display various images.

A liquid crystal display having an excellent colorful and decorative backlight display by arranging a fluorescent luminous body and two kinds of ultraviolet radiation lamps in a liquid crystal cell and using it as a backlight of a liquid crystal display device. This makes the device feasible.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a surface emitting device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Liquid crystal cell 3 Fluorescent light emitting plate 4 1st ultraviolet radiation lamp 5 2nd ultraviolet radiation lamp 6 Reflector 7 Driving means

Claims (3)

[Claims] 1. A first ultraviolet radiation lamp that emits ultraviolet light of a first wavelength range, and a second ultraviolet radiation that emits ultraviolet light of a second wavelength range different from the wavelength range of the first ultraviolet radiation lamp. A lamp, a phosphor that emits light when irradiated with ultraviolet light in the first wavelength range, and a fluorescent light emitter that includes both a phosphor that emits light when irradiated with ultraviolet light in the second wavelength range; By irradiating the ultraviolet radiation lamps individually or simultaneously, a plurality of types of fluorescent light are generated by the phosphor emitting by irradiation of the ultraviolet ray in the first wavelength range and the phosphor emitting by irradiation of the ultraviolet ray in the second wavelength range. A surface light-emitting device that emits light. 2. A UV-A wavelength range centered at approximately 365 nm as the first wavelength range, and a UV-C wavelength range centered at approximately 254 nm as the second wavelength range.
The surface emitting device according to any of the preceding claims. 3. A surface light-emitting device comprising a fluorescent light emitter and two kinds of ultraviolet light emitting lamps arranged in a liquid crystal cell and used as a backlight of a liquid crystal display device.