JP2000323756A - Sheet member and light-emitting device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet member, together with a light-emitting device using it which is easily installed on a small LED, capable of providing a luminous color with no unevenness in color tone and with less fluorescent material and coloring agent. SOLUTION: Related to a sheet member 1 attached to a substrate 2 comprising a light-emitting diode 3, a translucent coating part 2 comprising at least one of fluorescent material 13 and coloring agent 14 is provided only at a part facing the light-emitting diode 3. The sheet member 1 is preferred to comprise an engagement part for fitting to the substrate 2. More key switch parts allows change in color tone of LED with no increase in the number of parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet member having a coating portion for changing a light emission wavelength emitted from a light emitting diode (hereinafter sometimes referred to as "LED") to change a light emission color. The present invention relates to a sheet member capable of changing the color of light emitted from an LED simply by being mounted on a substrate having an LED, and a light emitting device using the same.

[0002]

2. Description of the Related Art As is well known, an LED chip is a crystal having a PN junction.
Holes move from the P region to the PN junction, respectively, and emit light when electrons and holes recombine. Since the energy released when free electrons are combined is emitted as light, only a limited number of LED chips are available. That is, LE having a red LED chip
D was red, the LED with the green LED chip emitted green light, and the LED with the blue LED chip emitted blue light only.

[0003] However, recently, there has been a strong demand for LEDs capable of changing colors according to versatile applications. Various methods have been proposed as color changing methods that satisfy such demands. For example, LED
Red LED chip, green LED chip, blue LE inside
A method has been proposed in which D chips are organically combined and set, and light emission is performed by changing the combination of each chip. However, such an LED requires a total of four terminals including a different anode terminal and a different cathode terminal for the red LED chip, the green LED chip, and the blue LED chip, resulting in a structurally complicated design. Is set with three different chips,
If any one of the chips is damaged, the balance of the color tone is lost, and there is a problem that a desired emission color cannot be obtained.

As another method, a method has been proposed in which a coating material or a paint containing a fluorescent substance is changed to a desired color by attaching or applying it to an LED. Recently, a white LED lamp in which a YAG (yttrium aluminate) phosphor layer is provided on a blue light emitting diode chip has been developed, and a coating material containing a coloring agent is mounted on the white LED lamp. Thus, a method of obtaining a desired emission color has been proposed. These methods are
This is an effective method for relatively large conventional LEDs, but it is difficult to install or apply the coatings and paints on small LEDs, whose use is rapidly expanding recently. Is reduced.

On the other hand, Japanese Utility Model Application Laid-Open No. 2-62748 proposes a technique in which a panel member containing a fluorescent substance is mounted on a printed circuit board provided with LEDs, although the desired effects are different. According to this proposed technique, even a small LED can be easily covered with a member containing a fluorescent substance, and the emission color can be changed to a desired color. However, in this structure, since the entire panel member contains a fluorescent substance, a large amount of expensive fluorescent substance is required and the cost increases.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and can be easily mounted on a small LED, and has a small amount of a fluorescent substance and a small amount of a coloring agent. It is an object of the present invention to provide a sheet member capable of obtaining a luminescent color without color tone unevenness and a light emitting device using the same.

[0007]

According to the present invention, there is provided a sheet member mounted on a substrate provided with a light emitting diode,
Only when facing the light emitting diode,
A sheet member provided with a light-transmitting covering portion containing at least one of a fluorescent substance and a coloring agent is provided.

At this time, the sheet member preferably has an engaging portion for fixing the sheet member to the substrate. In addition, it is desirable to further provide a key switch portion so that the color tone of the LED can be changed without increasing the number of components.

Preferably, the fluorescent substance is an yttrium aluminate-based phosphor or a perylene-based phosphor.

Further, according to the present invention, there is provided a light emitting device characterized in that the sheet member is mounted on a substrate having light emitting diodes. Hereinafter, the sheet member of the present invention will be described in detail.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have developed a coating which can be easily mounted even on a small LED, and which can provide a luminescent color without color tone unevenness with a small amount of fluorescent substance and coloring agent. As a result of intensive studies on the members, the covering member was formed into a sheet shape so as to cover not the LED itself but the substrate on which the LEDs were mounted, and when the sheet was mounted on the substrate, L
The present inventors have found out that the above-mentioned effect is exerted by providing a light-transmitting coating portion containing at least one of a fluorescent substance and a coloring agent only in the opposing portion of the ED, and have accomplished the present invention. That is, in the present invention, since the covering member is formed in a sheet shape so as to cover the substrate on which the LED is mounted, mounting is easy, and further, only the opposing portion of the LED at the time of mounting the sheet contains at least one of a fluorescent substance and a colorant. Since the translucent covering portion is provided, the amount of the fluorescent substance and the coloring agent used can be reduced as compared with the related art.

(Translucent coating) The translucent coating is prepared by separately producing a translucent coating member containing at least one of a fluorescent substance and a colorant, and welding the translucent coating member to a corresponding portion of the sheet substrate. Alternatively, it can be formed by adhering, or vulcanizing and bonding with a sheet base material when forming and processing a sheet member by placing a translucent covering member processed into a predetermined shape in a mold.

When the light-transmitting covering member is formed into a sheet shape, for example, a fluorescent substance and a binder resin are melted and kneaded, and are molded by an inflation method, a T-die method, a solution casting method, a calendar method, or the like. I just need. Further, a fluorescent material and / or a coloring agent may be coated on a base sheet made of a plastic film or the like to form a sheet.
Examples of such a coating method include a method in which a substance obtained by dissolving a fluorescent substance and / or a colorant in an organic solvent is coated by drying with hot air, or a method in which a synthetic resin emulsion is applied and dried to form a polymer on a substrate sheet. A method of forming a film or the like can be used.

The fluorescent substance is not particularly limited, and a known fluorescent substance such as a fluorescent substance, a fluorescent pigment, and a fluorescent dye can be used. For example, organic phosphors include allylsulfonamide / melamine formaldehyde co-condensed dyes and perylene phosphors, and inorganic phosphors include aluminates, phosphates, silicates and the like. Can be. Among these, a perylene-based phosphor and yttrium aluminate are particularly preferable because they can be used for a long time. Examples of the activator added to the phosphor include elements such as cerium, europium, manganese, gadolinium, samarium, terbium, tin, and chromium. Of these, cerium is preferred. The addition amount of the activator is preferably in the range of 0.1 to 10 mol% based on the phosphor. As a combination of the phosphor and the activator, a combination of yttrium aluminate and cerium is preferable.

The content of the fluorescent substance in the coating member is preferably 0.0001 to 10 parts by weight for an organic fluorescent substance and 0.5 for an inorganic fluorescent substance per 100 parts by weight of a binder resin.
The range of -70 parts by weight is preferred.

In order to adjust the color of light emitted through the light-transmitting coating to an arbitrary color, a colorant may be contained together with the fluorescent substance. If the LED emission color is white,
Even if only the coloring agent is used, the light emitted from the light-transmitting coating portion can be set to a desired emission color. Examples of the colorant that can be used in the present invention include, as yellow pigments, graphite, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S, Hansa yellow G, Hansa Yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, tartrazine lake; as an orange pigment, red-mouthed lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange,
Indus Ren Brilliant Orange RK, Benzidine Orange G, Indus Ren Brilliant Orange GK; Condensed azo pigments, Bengala, Cadmium Red, Lead Tan, Mercury Sulfide Cadmium, Permanent Red 4R, Risor Red, Pyrazolone Red, Watching Red Calcium as red pigments Salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B,
Alizarin lake, brilliant carmine 3B; violet pigment, manganese purple, fast violet B, methyl violet lake; blue pigment, navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue Chlorinated compounds, Fast Sky Blue, Indaslen Blue BC; green pigments: chrome green, chromium oxide, pigment green B, malachite green lake, fanal yellow green G; white pigments: zinc white, titanium oxide, antimony white, sulfide Zinc; as a white pigment, baryte powder, barium carbonate, clay, silica, white carbon, talc, alumina white and the like can be used.

The colorant is preferably used in an amount of 0.001 to 0.1 part by weight, particularly 0.01 to 0.05 part by weight, per 100 parts by weight of the binder resin.

The binder resin is not particularly limited, and may be, for example, an acrylic resin, a polycarbonate resin, a polystyrene resin, a polyester resin, an epoxy resin, a polypropylene resin, a polyethylene resin, a silicone-based elastomer, a polystyrene-based thermoplastic elastomer, or a polyolefin-based thermoplastic. Resins such as elastomers and polyurethane thermoplastic elastomers can be used, and among them, silicone elastomers and the like are preferably used.

(Sheet Member) On the other hand, as the resin serving as the base material of the sheet member of the present invention, those exemplified as the binder resin used in the above-mentioned light-transmitting covering material can also be used here. These resins are formed into a predetermined sheet shape by injection molding or extrusion molding. The shape of the sheet member may be appropriately determined so as to cover the entire surface or a part of the substrate in consideration of the shape of the substrate to be mounted, the arrangement position of the LEDs, and the like.

The LED disposed on the substrate may be any known LED, for example, Ga: ZnO red LE
D, GaP: N green LED, GaAsP red LED,
GaAsP orange / yellow LED, GaAlAs LE
D, InGaAlP-based orange / yellow LED, GaN-based blue L
ED, SiC blue LED, II-VI group blue LED, blue L
Examples include a white LED in which a phosphor layer is provided on an ED chip. In order to change the emission color by the translucent covering portion, a high-energy blue LED and a white LED are preferable, and a green LED or another high-energy LED subsequent thereto is preferable. The form of the LED may be any form, and for example, an LED lamp, a chip type LED, a segment type LED and the like can be suitably used. Of course, a small LED having a side of 1 mm or less may be used.

EXAMPLES Hereinafter, the sheet member of the present invention will be described in detail. One embodiment of the sheet member of the present invention is shown in FIG. The sheet member 1 is
Translucent coating 1 containing fluorescent substance 13 and colorant 14
2 and a base material 11, and the light-transmitting coating portion 12
Are provided only in a portion facing the LED 3 mounted on the LED. In order to partially provide the translucent covering portion 12, for example, in accordance with the shape of the LED, a translucent covering member such as a sheet containing a fluorescent substance and a coloring agent is separately prepared,
This is welded or adhered to the corresponding portion of the sheet substrate 11, or vulcanized and adhered to the sheet substrate 11 at the time of forming the sheet member 1 by placing a light-transmitting covering member of a predetermined shape in a mold. do it. The thickness of the sheet member 1 is not particularly limited. However, if the distance between the LED 3 and the light-transmitting coating portion 12 is not uniform, a color tone unevenness occurs in the emission color.
It is desirable to adjust the height of the sheet member 1 so that the inner side surface of the sheet member 2 contacts the upper surface of the LED 3. In the case of the embodiment shown in FIG. 1, the thickness of the base material 11 is set as the height of the LED 3,
The light-transmissive covering portion 12 is cut out from a separately prepared light-transmissive covering member according to the shape of the LED, and is adhered to the base material 11 to form the light-transmissive covering portion.

FIG. 2 shows another embodiment of the sheet member of the present invention.
Shown in This sheet member is provided with a fixed foot 4, and a hole 5 is provided on the other substrate 2 side at a position facing the fixed foot 4. 1 can be accurately positioned and mounted on the substrate 2. Of course, any known means other than fitting can be used as the means for engaging the sheet member and the substrate.

FIG. 3 shows still another embodiment of the sheet member of the present invention. The sheet member 1 includes a light-transmitting coating 1
2 and a key switch section 6. Key switch section 6
Has a switch 7 protruding on the sheet member 1 and a conducting portion 8 formed on the top of the inner surface thereof. When the switch 7 is pressed, the switch 7 is elastically deformed downward as a whole,
The conducting portion 8 comes into contact with the divided electrodes 9 and 9 'disposed at the substrate-side facing position of the key switch portion, and the switch is turned on. As described above, by forming the translucent covering portion on a member conventionally used as a panel member or a rubber keyboard, the effects of the present invention can be obtained without increasing the number of members.

FIGS. 4 and 5 show another embodiment further including a key switch section. In the embodiment of FIG. 4, the substrate 2 is provided with the LED 3 and the dome-shaped elastic portion 15 having the conducting portion 8 at the top of the inner surface and formed so as to cover the divided electrodes 9 and 9 ′. The switch 7 elastically deforms the elastic portion 15 located below the switch, and the conductive portion 8 at the top of the inner surface of the elastic portion 15 comes into contact with the divided electrodes 9 and 9 ′ disposed at the substrate-side opposing position to switch the switch. Is entered.

The embodiment shown in FIG. 5 is a keyboard having a structure in which the base member 2, the sheet member 1, the switch member 17, and the protective cover 18 are laminated in this order. FIG. 4 shows that the substrate 2 is provided with the dome-shaped elastic portion 16 and the LED 3.
However, the elastic portion 16 is made of a conductive material such as a metal, and is turned on when the elastic portion 16 comes into contact with the divided electrodes 9 and 9 ′. No part is provided. The sheet member 1 includes:
The translucent covering portion 12 is provided at a position facing the LED 3 mounted on the base member 2 without any step from the sheet base member 11.
The switch member 17 is provided with a switch 7 protruding above the elastic portion 16.
Since the protective cover 18 covering the switch 7 is cut out only at the switch 7, the switch 7 projects outward. In such a keyboard, when the switch 7 is pressed, the switch 7 elastically deforms the elastic portion 15 located below the switch 1 through the sheet member 1 downward, and
5, a divisional electrode 9 in which a part of 5 is disposed at a position facing the substrate side;
9 'comes into contact with the switch. LED
The light emitted from 3 passes through the upper translucent portion 12 and is converted into a desired color by a fluorescent substance or a coloring agent at this time, and proceeds to the switch member 17 to form a sheet as indicated by a broken line in the figure. The reflection is repeated by the member 1 and the protective cover 18, the light travels in the switch member 17 in the left-right direction in the drawing, and is radiated from the cutout portion of the protective cover 18, that is, the portion of the switch 7 to the outside. As a result, the switch portion lights up brighter.

[0026]

According to the seat member of the present invention, a small L
It can be easily mounted on the ED, and a luminescent color without color tone unevenness can be obtained with a small amount of a fluorescent substance and a small amount of a coloring agent.

[Brief description of the drawings]

FIG. 1A is a plan view of a light emitting device according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line II ′ in FIG.

FIG. 2 is a sectional view showing an embodiment of the invention according to claim 2;

FIG. 3 is a sectional view showing an embodiment of the invention according to claim 3;

FIG. 4 is a sectional view showing another embodiment of the invention according to claim 3;

FIG. 5 is a sectional view showing still another embodiment of the invention according to claim 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet member 2 Substrate 3 LED 4 Fixed foot 5 hole 6 Key switch part 7 Switch 8 Conduction part 9, 9 'Split electrode 11 Sheet base material 12 Translucent covering part 13 Fluorescent substance 14 Colorant 15, 16 Elastic part 17 Switch Member 18 Protective cover

Claims (5)

[Claims] 1. A sheet member to be mounted on a substrate provided with a light emitting diode, wherein a light transmitting coating containing at least one of a fluorescent substance and a coloring agent is provided only on a portion facing the light emitting diode when mounted. A sheet member characterized by being provided. 2. The sheet member according to claim 1, further comprising an engagement portion for fixing to the substrate. 3. The system according to claim 1, further comprising a key switch unit.
Or the sheet member according to 2. 4. The sheet member according to claim 1, wherein the phosphor is an yttrium aluminate-based phosphor or a perylene-based phosphor. 5. A light emitting device, wherein the sheet member according to claim 1 is mounted on a substrate having light emitting diodes.