JPH08202301A - Light accumulation type light emitting body - Google Patents

Abstract

PURPOSE: To realize a light accumulation type light emitting body with which an improvement in function is possible, management is easy and afterglow time is long and which is easily visible and has excellent practicability, ornamentability, amusementability and safety. CONSTITUTION: This light accumulation type light emitting body 10 is composed of a base plate 11 which is formed by adding, for example, a transparent acrylic resin with a light accumulation material formed by adding a rare earth element to a metal oxide base sintered material at a mixing ratio of 30% and a light shielding layer 12 consisting of a blank stamp formed over the entire part on the front surface of this base plate 11. The side faces of the base plate 11 are formed to tapered surfaces 11a flaring from the front surface side toward the rear surface side to increase a light incident area and to allow the recognition of characters from the front even at nighttime.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminous phosphor which can be used in a dark place.

[0002]

2. Description of the Related Art Generally, a luminous material containing zinc sulfide as a main component is used for a dial for a timepiece, a luminous body for an hour hand and a minute hand. From a design point of view, the phosphorescent material is mixed with a pigment of a dedicated color. Zinc sulfide has a yellowish green color. The coloring lowers the brightness and shortens the afterglow time. When it is used in a dark place, it is impossible to read characters etc. on a watch dial in about 20 minutes.
Therefore, conventionally, in order to prevent the afterglow time from being shortened, a radioactive substance such as promethium is combined to spontaneously emit light, thereby maintaining a brightness of 0.3 mcd or more which can be visually recognized by humans.

[0003]

However, since the conventional luminous body is added with a radioactive substance to maintain the brightness, the amount of radiation is 10 according to the regulation of "Radioactive Disability Prevention Law".
Limited to less than 0 microcurie. Therefore, it cannot be used for a wall clock having a large dial area and a large amount of usage, and its use is limited to a clock having a small dial area such as an alarm clock. In addition, enormous management costs are required due to the regulations of the "Radioactive Disorder Prevention Law" mentioned above.

Therefore, the applicant of the present invention has proposed a phosphorescent type light emitting device which is easy to manage, has a long afterglow time, and is easy to see and can be used for a wide range of purposes. And a transparent phosphorescent layer made of metal oxide ceramics such as alumina containing alkaline earth metal is arranged (Japanese Patent Application No. 5-338).
169).

This light-emitting device reacts with light of a predetermined wavelength, for example, a fluorescent lamp having a large amount of ultraviolet rays or sunlight to store energy and emit light for a predetermined time. The brightness is higher than that of the conventional phosphorescent light emitting body made of zinc sulfide, and the afterglow time is 5 to 8 times longer than that of the phosphorescent light emitting body made of zinc sulfide.
Time is maintained. Therefore, it can be sufficiently applied to an alarm clock and the like. Further, there is an advantage that a phosphorescent material similar to that colored can be manufactured in a pseudo manner by changing the printing color or the coating color of the underlayer to a desired color.

However, in this light emitting device, since the transparent phosphorescent layer is arranged on the flat base plate, the incident path of light is limited, and the amount of excitation light from the outside is restricted, and its brightness and There was a limit to the duration of light emission.

Further, as a time character for a timepiece using this light emitting device, for example, as shown in FIG. 6, an underlayer 1 having a high lightness such as white or yellowish green is used and its contour is clearly defined. Therefore, the black print 2 is applied to the outer peripheral portion of the character, but this impairs the original function of the timepiece, which is easy to see the time of day.

The present invention has been made in view of such circumstances, and an object thereof is to improve the function, to manage easily, to have a long afterglow time, and to be easy to see, practicality, decoration, and play. It is to provide a phosphorescent light-emitting body having excellent properties and safety.

[0009]

In order to achieve the above object, the phosphorescent-type luminescent material of the present invention is an optically transparent base containing at least a phosphorescent material obtained by adding a rare earth element to a metal oxide-based sintered material. And a light-shielding layer formed on at least a part of the upper surface of the base, and at least a part of the side surface of the base is formed to project laterally from the upper surface. At least a part of the side surface of the base is tapered.

[0010]

According to the luminous phosphor of the present invention, there is no restriction on the incident path of light having a predetermined wavelength, which is the excitation light, and at least the region where the light shielding layer of the three-dimensional base of the excitation light is formed is excluded. It is incident on the base from the entire side surface. Further, since at least a part of the side surface of the base is formed to project laterally from the upper surface, that is, is formed in a tapered shape so as to protrude, the incident area of light is larger than that of a normal rectangular parallelepiped shape, and the amount of excitation light is larger. Is often incident. As a result, the added rare earth element receives a large amount of light and becomes in a highly excited state.
Therefore, the base emits light radially with high brightness. This light is emitted directly or diffusely reflected outside the base. As a result, the light-emitting body except the region where the light-shielding layer is formed emits light with high brightness.

[0011]

1 and 2 are views showing an embodiment of a luminous phosphor according to the present invention. FIG. 1 is a perspective view thereof, and FIG. 2 is an enlarged sectional view taken along line AA of FIG. It is a figure. The phosphorescent light-emitting body in the present embodiment shows a configuration example in the case of being applied as a time character for a timepiece. Here, the numeral "1" is given as a representative example.

As shown in FIG.
For example, a phosphorescent material obtained by adding a rare earth element to a metal oxide-based sintered material is added to a transparent acrylic resin at a mixing ratio of 30%, and a base 11 having a trapezoidal cross section and the entire upper surface of the base 11 are provided. Light-shielding layer 1 consisting of a black stamp formed over
2 and. The side surface of the base 11 is formed to have a tapered surface 11a that widens toward the bottom from the upper surface so that the light incident area can be increased and the characters can be recognized from the front even at night. The base 1 has a height set to, for example, about several millimeters and is formed by fusion or the like.

The phosphorescent material added to the base 10 is, for example, a sintered oxide of a metal and an alkaline earth metal element, and a few pp.
It is composed by adding a trace amount of rare earth element of about m.
A sintered oxide of a metal and an alkaline earth metal element functions as a light emitting body, and a rare earth element functions as a catalyst for transition to an excited state. Here, aluminum (Al) is used as the metal of the sintered oxide, and strontium (Sr) is used as the alkaline earth metal. The chemical formula of the sintered oxide in this case is as follows. Sr _x · Al _y · O _Z

Such a phosphor is slightly yellowish green and has higher transparency than conventional zinc sulfide, and as shown in FIG. 3, zinc sulfide (ZnS) which is a conventional general phosphorescent material.
Longer afterglow and higher brightness. In addition, the phosphorescent material stores energy in response to fluorescent light or sunlight, which has a large amount of ultraviolet rays. A good wavelength is about 370 nm.

FIG. 4 is a graph showing the results of measuring the afterglow time of the present luminescent material, the conventional phosphorescent luminescent material using zinc sulfide and the self-luminous luminescent material to which promethium is added. In FIG. 4, the horizontal axis represents the irradiation time and the afterglow time, and the vertical axis represents the afterglow brightness. Further, in the figure, the curve indicated by A-1 shows the characteristics of the luminescent material using the phosphorescent material according to the present invention arranged on the white background printing color, and the curve indicated by A-2 shows the yellow green color on the white background printing color. The characteristics of the luminous body using the phosphorescent material according to the present invention arranged by including the pigment of
The curve indicated by is the characteristic of the luminous body using the phosphorescent material according to the present invention arranged on the color printing color, the curve indicated by B is the conventional luminous element made of zinc sulfide, and the curve indicated by C is self-luminous. The characteristics of the type light emitter are shown respectively. As can be seen from FIG. 4, the present luminous body has higher brightness than the conventional luminous body,
The afterglow time is about 5 to 8 hours, which is ten times longer than that of the phosphorescent light emitting body using zinc sulfide. As described above, since it has the afterglow characteristic for a long time, it can be sufficiently applied as a watch or a decoration even at night when the illumination is turned off.

Luminescent phosphor 10 having such a structure
In this case, a predetermined wavelength (37
The incident path of the light of 0 nm) is not restricted, and the excitation light is incident on the three-dimensional base 11 from the entire side surface 11a except the region where the light shielding layer 12 is formed. In addition, the base side surface 11
Since a is formed in a tapered shape, the incident area of light is larger than that of a normal rectangular parallelepiped shape, and a large amount of excitation light is incident. As a result, the base 11 receives a large amount of the added rare earth element and is in a high excited state, and the base 11 emits light radially with high brightness. This light is emitted to the outside of the base 11 either directly or after being diffusely reflected. As a result, the light emitting body 10 excluding the region where the light shielding layer 12 is formed emits light with high brightness. Base side 11a
Is tapered, the light emission surface is
Since it is located around the black stamped upper surface, this three-dimensional side surface 11a emits light and becomes the outline of the character-shaped light-shielding layer 12, so that the time characters can be easily and clearly recognized even at night.

Further, since the black stamp is provided on the entire upper surface of the base 11, the time characters can be clearly recognized even in the daytime.

As described above, according to this embodiment,
The phosphorescent material of the present phosphorescent type light-emitting body 10 is made of, for example, a transparent acrylic resin, a phosphorescent material obtained by adding a rare earth element to a metal oxide-based sintered material with a mixing ratio of 30%, and a base 11 having a trapezoidal cross section. And a light-shielding layer 12 made of a black stamp formed over the entire upper surface of the base 11.
The side surface of the is formed to have a tapered surface 11a that widens from the upper surface to the lower surface so that the light incident area can be increased and the characters can be recognized from the front even at night. Therefore, the function can be improved. In addition, it is possible to realize a phosphorescent light-emitting body which has a long afterglow time, is easy to see, and is excellent in practicality, decoration, playability, and safety. Further, since it is safe without using a radioactive substance, it can be applied as a large light emitting device, the application such as decoration can be expanded, and the member management cost can be reduced.

In the present embodiment, the numeral "1" has been described as an example, but the present invention is not limited to this, and not only the time character for a clock but also a decorative character of another device or Various modes such as a clock hand, a scale, and an alarm clock stop button are possible. In addition, in the present embodiment, the case where the entire surface of the base 11 is made black by a black stamp is used as the light shielding layer 12 has been described as an example. However, as shown in FIG. Various embodiments such as layer 12a are possible.

[0020]

As described above, according to the present invention,
It is possible to realize a light-storing luminescent material with improved functions, long afterglow time, and easy to see, which is excellent in practicality, decoration, playability, and safety. Further, since no radioactive substance is used, it can be applied as a large light emitting device. Further, since no colorant is mixed in the phosphorescent material, there is an advantage that the afterglow time and the brightness can be maintained high.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a luminous phosphor according to the present invention.

FIG. 2 is an enlarged cross-sectional view taken along line AA of FIG.

FIG. 3 is a diagram for comparing the afterglow time of a phosphorescent light emitting device according to the present invention and a conventional phosphorescent light emitting body using zinc sulfide.

FIG. 4 is a graph showing the results of measuring the afterglow time of a luminescent material according to the present invention and a conventional phosphorescent luminescent material using zinc sulfide and a self-luminous luminescent material to which promethium is added.

FIG. 5 is a diagram showing another configuration example of the light shielding layer according to the present invention.

FIG. 6 is a diagram for explaining a general configuration example of a character using a luminous phosphor.

[Explanation of symbols]

 10, 10a ... Luminescent luminous body 11 ... Base 12, 12a ... Light-shielding layer

Claims (2)

[Claims] 1. An optically transparent base including at least a phosphorescent material obtained by adding a rare earth element to a metal oxide-based sintered material, and a light-shielding layer formed on at least a part of the upper surface of the base. Then, the phosphorescent light-emitting body formed so that at least a part of the side surface of the base is projected laterally from the upper surface. 2. The luminous phosphor according to claim 1, wherein at least a part of a side surface of the base is tapered.