JP2006165416A - White-color displaying device, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the manufacturing method of a white-color displaying device which improves the contrast of its display and can be manufactured at a low cost by a simple constitution. <P>SOLUTION: The manufacturing method of the white-color displaying device is so constituted as to include a first step for so disposing a hollow lamp house 10 having in its front surface an opening 10a for the shapes of numerals and characters, etc. and having its released bottom surface as to direct its displaying surface toward its down side, a second step for injecting into the hollow portion of the lamp house 10 whose displaying surface is so disposed in the first step as to direct it toward down side a transparent resin material 12 having an entrapped dispersing agent and entrapped phosphors, a third step for setting subsequently in the hollow portion of the lamp house electrode members 14 having mounted LED chips, and a fourth step for thereafter so storing in a thermostatic oven the lamp house having the injected transparent resin material and the set electrode members as to deposit the phosphors on the front-surface side and as to harden transparent resin layers 12b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a white display that displays numbers, characters, and the like with white light.

Conventionally, the white numeral display is configured as shown in FIG. 6 or FIG. 7, for example.
First, in FIG. 6, the white number display 1 is comprised by sticking the white conversion film 3 on the number display surface 2a of what is called a mold type blue number display 2 which uses blue LED as a light emission source. Yes.

The blue LED is composed of an element made of, for example, GaN, InGaN, SiC, or the like.
The white conversion film 3 is configured to convert, for example, blue light from the blue number display 2 into yellow light, and emit white light to the outside by color mixture with the blue light. 2 is affixed on the number display surface 2a with an acrylic adhesive or the like, for example.
As an LED display device using such a white conversion film, there is, for example, Patent Document 1.

In FIG. 7, the white numeral display 4 has a white or three-color chip LED 6 mounted on a printed wiring board 5, and a lamp house 7 is thermally welded or bonded on the printed wiring board 5. Further, the diffusion film 8 is attached on the numeric display surface 7 a of the lamp house 7.
JP-A-10-215002

However, these white numerical indicators 1 and 4 have the following problems.
That is, in the white number display 1 shown in FIG. 6, since the white conversion film 3 is affixed on the number display surface 2a of the blue number display 2 with an acrylic adhesive, for example, heat and mechanical stress Therefore, it is easy to peel off and it is impossible to cope with dip soldering.
Moreover, since the white conversion film 3 has a yellowish appearance due to, for example, a phosphor mixed therein, the contrast between the light emitting portion and the non-light emitting portion is low, and the display visibility is reduced. Will end up.

On the other hand, in the white number display 4 shown in FIG. 7, since a mounting space for mounting the LED chip on the printed wiring board 5 is required, it is difficult to display a small number, Usually, the character height becomes 15 mm or more.
Moreover, since the diffusion film 8 is affixed on the number display surface 7a of the lamp house 7, the contrast between the light emitting part and the non-light emitting part is low, and the visibility of the display is lowered.
Furthermore, since the printed wiring board 5 is comprised from a glass epoxy board | substrate and chip LED is used, cost will become high.

Furthermore, even in the white display 1 described above, if there is variation in the emission color of the blue LED that is the light source of the blue number display 2, a desired white point may not be obtained.
Further, such a problem occurs not only in the white numeral display but also in a white display that displays characters and the like.

  In view of the above, an object of the present invention is to provide a method for manufacturing a white display device which can improve display contrast and can be manufactured at a low cost with a simple configuration.

  The above object, according to the present invention, is a first stage of disposing a hollow lamp house having openings on the surface in the shape of numbers, letters, etc. and having a bottom surface open, In the first stage, a second stage of injecting a transparent resin material mixed with a diffusing agent and a phosphor into the hollow part of the lamp house where the display surface is arranged downward, and then in the hollow part of the lamp house. The third step of setting the electrode member on which the LED chip is mounted, and then injecting the transparent resin material and placing the lamp house in which the electrode member is set in the thermostatic chamber, the phosphor is allowed to settle to the surface side. And a fourth step of curing the transparent resin layer. This is achieved by a method for manufacturing a white display device.

  In the method for producing a white display according to the present invention, preferably, in the fourth stage, the phosphor in the transparent resin material is sufficiently settled to keep the transparent resin material in a low viscosity state for a relatively long time. It is cured at a relatively low temperature so as to maintain it over time.

  In the method for producing a white display according to the present invention, preferably, the transparent resin material is an epoxy resin, and the curing of the transparent resin layer in the fourth stage is held at 60 ° C. for 4 hours, and then 110 It is carried out by holding at 3 ° C. for 3 hours.

  In the method for manufacturing a white display according to the present invention, the inner wall surface of the opening of the lamp house is preferably inclined obliquely so as to expand upward.

  In the white display manufacturing method according to the present invention, preferably, the inner wall surface of the opening of the lamp house extends vertically upward.

  In the method of manufacturing a white display according to the present invention, preferably, the region excluding the opening on the display surface of the lamp house is colored dark.

According to the above configuration, the phosphor having a specific gravity greater than that of the transparent resin can be obtained when the transparent resin material is cured in the fourth stage by mixing the phosphor in the transparent resin material in advance. A phosphor layer is formed by sedimentation on the surface side.
Thus, when the LED chip is fed through the electrode member and the LED chip emits light, the light from the LED chip travels toward the surface, and the phosphor layer formed on the surface side of the opening of the lamp house Is incident on. Thereby, the phosphor in the phosphor layer converts the light from the LED chip into white light, and the white light is emitted to the outside.

  In this case, since there is no white conversion film or diffusion film attached like the conventional white numeric display, there is no problem of film peeling, and when mounting on a mounting board, dip It can be soldered and can be handled in the same way as a conventional LED numeric display.

In addition, since it has the same configuration as a conventional mold type white display and uses an LED chip as a light source, it can handle small characters and can be manufactured at a low cost with a simple configuration. It is possible.
Furthermore, by appropriately adjusting the type and concentration of the phosphor mixed in the transparent resin material with respect to the variation in the color tone of the LED chip, it is possible to obtain a uniform white point with a small variation and correspondingly enough. Become.

  In the fourth stage, in order for the phosphor in the transparent resin material to sufficiently settle, the transparent resin material is cured at a relatively low temperature so as to maintain a low viscosity state for a relatively long time. In the case where the transparent resin material is cured at a low temperature, the transparent resin material is maintained in a low viscosity state for a relatively long time, so that the phosphor mixed in the transparent resin is sufficiently contained. By sedimentation, a phosphor layer having a relatively high concentration is formed.

  When the transparent resin material is an epoxy resin, and the curing of the transparent resin layer in the fourth stage is performed by holding at 110 ° C. for 3 hours after holding at 60 ° C. for 4 hours In this case, the phosphor is sufficiently precipitated in the epoxy resin having a low viscosity before curing.

  When the inner wall surface of the opening of the lamp house is inclined obliquely so as to expand upward, the lamp house used in a conventional mold type white display can be used as it is. This can reduce costs.

  In the case where the inner wall surface of the opening of the lamp house extends vertically upward, when the phosphor settles in the transparent resin material, the phosphor almost extends over the entire opening of the lamp house. It will settle uniformly and generation | occurrence | production of a color nonuniformity may be suppressed.

  When the area excluding the opening on the display surface of the lamp house is colored dark, the contrast between the light emitting part and the non-light emitting part is improved, and the visibility of numbers, characters, etc. by the light emitting part is improved. It will be.

  In this way, according to the present invention, a white display device is provided which improves the display contrast and can be manufactured at a low cost with a simple configuration.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS.
The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

1 to 3 show the configuration of a first embodiment of a method for manufacturing a white numeral display according to the present invention.
First, in FIG. 1, the lamp house 10 is attached side by side along the longitudinal direction of the molding tape 11 with its display surface facing downward.
Then, the transparent resin material 12 mixed with the diffusing agent and the phosphor is injected into the hollow portion from the opened bottom surface of the lamp house 10 by an appropriate injection means 13.

Here, as shown in FIG. 3, the lamp house 10 has the same configuration as that of the lamp house in the conventional numeric display, and includes an opening 10a for each segment constituting the numeral and an opening on the surface thereof. The region excluding the portion 10a is colored in dark color such as black or gray by painting or the like.
Moreover, the transparent resin material 12 mixed with the diffusing agent and the phosphor is prepared in advance, and the phosphor is added to the transparent resin material such as an epoxy resin mixed with the diffusing agent used in the conventional numeric display. It is constituted by.
In addition, as a fluorescent substance, the kind of fluorescent substance which converts the light from the LED chip mentioned later into white light is used, and the density | concentration is selected so that a desired white point may be obtained.

Next, as shown in FIG. 2, the LED chip 14 a is mounted on the chip mounting portion at a predetermined position, and the lead frame 14 electrically connected by die bonding and wire bonding is inserted into the hollow portion of each lamp house 10. And set at a predetermined position.
Here, the LED chip 14a is made of, for example, a nitride compound semiconductor that emits blue light or ultraviolet light.
The lead frames 14 are formed in a state in which the number corresponding to the plurality of lamp houses 10 is connected to each other by the connecting portions 14b, and the lead frames 14 are connected to the plurality of lamp houses 10 at a time. It can be set.

Thereafter, as described above, the transparent resin material 12 is injected, and the lamp house 10 in which the lead frame 14 is set is attached to the molding tape 11 and accommodated in a thermostat (not shown). The transparent resin material 12 is cured by being maintained at a predetermined temperature.
At that time, the phosphor mixed in the transparent resin material 12 is settled in the transparent resin material 12 due to the specific gravity larger than that of the transparent resin material 12 until the transparent resin material 12 is cured. The phosphor layer 12 a is formed near the bottom of the transparent resin material 12.

Here, in order to keep the low-viscosity state of the transparent resin material 12 for a long time so that the phosphor is sufficiently settled in the transparent resin material 12, in the above-described constant temperature bath, conventionally, The transparent resin material 12 is cured by so-called step cure at a low temperature, and the transparent resin layer 12b is formed.
For example, in the conventional numerical display, the transparent resin material is cured by maintaining at 85 ° C. for about 3 hours and then at 110 ° C. for 3 hours. In the embodiment of the present invention, however, the transparent resin material is cured. Is cured, for example, by maintaining at 60 ° C. for about 4 hours and then at 110 ° C. for 3 hours.

Finally, after the transparent resin material 12 is cured, the lamp house 10 is taken out of the thermostatic chamber, the molding tape 11 is removed, and the connecting portion 14b of the lead frame 14 is separated for each lamp house 10.
Thereby, as shown in FIG. 3, the white number display 20 is completed.

According to the white number indicator 20 manufactured in this way, by applying a driving voltage to the LED chip 14a via the pair of lead frames 14, the LED chip 14a emits light, and the light from the LED chip 14a is The light passes through the transparent resin layer 12b and enters the phosphor layer 12a formed near the surface thereof.
Then, the phosphor in the phosphor layer 12a is converted into white light and emitted to the outside. At that time, since the phosphor layer 12a is formed in the opening 10a provided for each segment constituting the number of the lamp house 10, each segment serves as a light emitting portion to emit white light. It will be.

Accordingly, when the LED chip 14a located in the opening 10a constituting each segment is selectively driven, each segment selectively becomes a light emitting unit corresponding to the combination of the LED chips 14a that emit light, and is arbitrarily selected. The number will be displayed.
In that case, since the area | region except the opening part 10a of the lamp house 10 is colored darkly as mentioned above, since a non-light-emitting part becomes dark colors, such as black or gray, a light-emitting part and a non-light-emitting part The contrast between the two is clear, and the visibility of numbers by light emission display is improved, so that the display quality is improved.

  Furthermore, since the conventional white conversion film and diffusion film are not affixed to the surface which is the display surface of the lamp house 10, the film does not peel off with use, and dip soldering is also possible. It can be handled in the same manner as a conventional mold type numeric display.

FIG. 4 shows a configuration of a white number display manufactured by the second embodiment of the method for manufacturing a white number display according to the present invention.
In FIG. 4, the white number display 30 is manufactured in the same manner as the white number display 20 shown in FIGS. 1 to 3, and only the shape of the inner wall surface of the opening 10 a of the lamp house 10 is different. ing.
Here, the inner wall surface of the opening 10a of the lamp house 10 extends substantially perpendicularly to the surface of the lamp house.

  According to the white numeral display 30 having such a configuration, the opening 10a defined by the inner wall surface is the same in the vertical direction while acting in the same manner as the white numeral display 20 shown in FIGS. Because of the shape, when the transparent resin material 12 is injected into the opening 10a of the lamp house 10, the phosphor layer 12a formed by the sedimentation of the phosphor is uniformly over the entire surface of the opening 10a. By sedimentation, a uniform concentration or thickness is formed.

By the way, in the case of the white numeral display 20 shown in FIGS. 1 to 3, the opening 10a is enlarged toward the surface as shown in FIG. When the transparent resin material 12 is injected into the transparent resin material 12, the transparent resin material 12 spreads around the opening 10a, and the phosphor layer 12a formed by the sedimentation of the phosphor becomes thin near the periphery. Or the phosphor concentration will decrease.
Therefore, when the phosphor layer 12a is relatively thin, or when the phosphor concentration in the transparent resin material 12 is relatively low, the above-described influence appears remarkably, and in the vicinity of the periphery of the opening 10a, the phosphor The amount of light is reduced, and white conversion by the phosphor is insufficient, resulting in bluish light.

  By the way, in the white numeral display 30 according to FIG. 4, the thickness of the phosphor layer 12a or the phosphor concentration is uniform, so that the color unevenness in the vicinity of the opening 10a as described above occurs. However, uniform white light can be obtained in the opening 10a, that is, the entire segment.

In the embodiment described above, blue light or ultraviolet light emitted from the LED chip is converted to white by the phosphor of the phosphor layer 12a. However, the present invention is not limited to this, and the light emitted from the LED chip is converted into white light. Can be selected, LED chips and phosphors of any emission color can be selected.
Further, in the above-described embodiment, the case where the white number indicators 20 and 30 are manufactured has been described. However, the present invention is not limited to this. For example, each lamp house having an opening corresponding to a character segment is used. By providing an LED chip corresponding to the segment, it can be configured as a white character display.
Furthermore, in the above-described embodiment, the lead frame 14 is used to supply the drive voltage to the LED chip 14a. However, the present invention is not limited to this, and other electrode members, for example, a substrate with lead pins are used. It is clear that it is good.

  As described above, according to the present invention, it is possible to provide a method of manufacturing a white display device which can improve display contrast and can be manufactured at a low cost with a simple configuration.

It is a schematic perspective view which shows the 1st and 2nd step in 1st embodiment of the manufacturing method of the white number display by this invention. It is a figure which shows the 3rd step in 1st embodiment of the manufacturing method of the white number display by this invention. It is a schematic sectional drawing which shows the structure of the white number display manufactured by the manufacturing method shown in FIG.1 and FIG.2. It is a schematic sectional drawing which shows the structure of the white number display manufactured by 1st embodiment of the manufacturing method of the white number display by this invention. It is explanatory drawing which shows generation | occurrence | production of the color nonuniformity in the white number display of FIG. It is (A) schematic perspective view and (B) exploded perspective view which show the structure of an example of the conventional white numerical display. It is (A) schematic perspective view and (B) exploded perspective view which show the structure of the other example of the conventional white number display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lamphouse 10a Opening part 11 Mold tape 12 Transparent resin material 12a Phosphor layer 12b Transparent resin layer 13 Injection | pouring means 14 Lead frame 14a LED chip 14b Connection part 20,30 White number indicator

Claims (6)

A first stage in which a hollow lamp house having openings in the shape of numbers, letters, etc. on the surface and the bottom surface being opened is arranged with the display surface facing downward;
Next, a second step of injecting a transparent resin material mixed with a diffusing agent and a phosphor into the hollow portion of the lamp house in which the display surface is arranged downward in the first step,
Subsequently, a third stage of setting an electrode member mounted with an LED chip in the hollow portion of the lamp house,
Then, a transparent resin material is injected and a lamp house in which an electrode member is set is placed in a thermostatic chamber, the phosphor is allowed to settle on the surface side, and the transparent resin layer is cured,
Including,
A method of manufacturing a white display device.   In the fourth stage, in order for the phosphor in the transparent resin material to sufficiently settle, the transparent resin material is cured at a relatively low temperature so as to maintain a low viscosity state for a relatively long time. The method for manufacturing a white display according to claim 1, wherein:   The transparent resin material is an epoxy resin, and the curing of the transparent resin layer in the fourth stage is performed by holding at 110 ° C. for 3 hours after holding at 60 ° C. for 4 hours. The method for producing a white display according to claim 1 or 2, characterized in that   4. The method for manufacturing a white display device according to claim 1, wherein an inner wall surface of the opening of the lamp house is inclined obliquely so as to expand upward. 5.   4. The method for manufacturing a white display device according to claim 1, wherein an inner wall surface of the opening of the lamp house extends vertically upward. 5.   6. The method for manufacturing a white display device according to claim 1, wherein a region excluding the opening portion of the display surface of the lamp house is colored in dark color.

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