JP5638214B2 - Method of manufacturing surface light emitter with electrical wiring by ink jet printing - Google Patents

Description

  The present invention relates to a surface light emitter using a plurality of LED elements, and particularly to a novel method of manufacturing a surface light emitter formed by ink jet printing when forming an electrical wiring on a substrate of the surface light emitter. It is concerned.

Conventionally, fluorescent lamps have been often used as light sources for internally illuminated signboards, but they have a longer lifespan, lower power consumption, and can produce a variety of colors. LED elements are also frequently used. Among such LED-type internally illuminated signboards, a three-dimensional character-shaped signboard (referred to as a character signboard or a box character signboard) having a hollow (box shape) inside has already been devised (for example, Patent Document 1).
For example, as shown in FIG. 5, an LED-illuminated character signboard SB ′ disclosed in Patent Document 1 includes a reflector plate R having a bowl shape (concave curved surface) in a signboard case 2 ′. In this case, the light is applied to the reflector R from both ends of the LED element 13 ', and the light once reflected by the reflector R (indirect light) is displayed on the display unit. 21 'is transmitted.

However, in such a box character signboard SB ′, since the reflector R is essential, the structure is not necessarily simple, and there is a problem that the number of parts increases. Moreover, in this patent document 1, compared with a box character signboard using a fluorescent lamp as a light source, although the projecting dimension from the wall surface (thickness as the signboard SB ') can be shortened, there is a limit to the provision of the reflector R. There was a need for a thinner box letter sign.
For this reason, it is conceivable that the light emitted from the LED element 13 'is directly transmitted from the display unit 21' without using the reflector R. However, the surface light emitters used for this type of signboard have LED elements 13 'arranged in advance at the same pitch in both the vertical and horizontal directions (so-called modularization), which is generally used for general purposes. (For example, see Patent Document 2).

  In this regard, the box character signboard SB ′ has a light emitting surface (display unit 21 ′) that is not a simple rectangular shape. Therefore, when the modularized LED unit as described above is used, it is difficult to uniformly illuminate the light emitting surface. There was a case. That is, for example, as shown in FIG. 6, when the light emitting surface (display unit 21 ′) is an equilateral triangle and a modularized LED unit is used, the arrangement balance of the LED elements 13 ′ is arranged at the edge portion of the light emitting surface. There is a problem that the light is uneven and the light unevenness easily occurs at the time of lighting. Here, symbol Z in the figure is a portion where light unevenness is likely to occur during lighting. Incidentally, in order to illuminate such a light emitting surface (display portion 21 ') as a whole uniformly, for example, as shown in FIGS. 6B and 6C, the LED elements 13 are arranged along the contour of the light emitting surface. Preferably, this is an installation form that is difficult to achieve when modularized LED units (LED elements 13 arranged at the same pitch both vertically and horizontally) are used. In FIGS. 6B and 6C, 10 and 15 LED elements 13 are installed, respectively, but this is because the number of LED elements 13 ′ used in FIG. 6A is 13. This is because they are arranged with a similar number of elements in view of almost the same brightness.

FIG. 7 (a) shows a case where the light emitting surface (display unit 21 ′) is circular. This figure shows that when a modularized LED unit is used, an LED is also formed near the edge of the light emitting surface. This shows that the arrangement balance of the elements 13 'is not uniform, and light unevenness is likely to occur at the portion (the portion indicated by the symbol Z) during lighting. Of course, also in this case, in order to illuminate the light emitting surface uniformly as a whole, it is preferable to arrange the LED elements 13 along the contour of the light emitting surface, for example, as shown in FIG.
As described above, a new LED type surface light emission of a so-called on-demand system that can handle such a box character signboard without using a modularized LED unit for the box character signboard described above. The body was sought.

Utility Model Registration No. 3093362 International Publication WO / 2009/054153

  The present invention has been made by recognizing such a background. Normally, even a box character signboard having a different light emitting surface for each signboard can be illuminated uniformly using LED elements. It is an object of the present invention to provide a novel on-demand method for manufacturing a surface light emitter.

First, a method for manufacturing a surface light emitter having electrical wiring by ink jet printing according to claim 1 is as follows:
A substrate with electrical wiring;
In a method of manufacturing a surface light emitter comprising a plurality of LED elements arranged with respect to the substrate,
The electrical wiring is formed on the substrate by inkjet printing ,
Further, among the plurality of LED elements, at least some of the mounting positions are determined from the contour line of the light emitting surface along the assumed arrangement line with a substantially constant interval,
On the other hand, the electrical wiring is formed on the substrate so as to connect them in series according to the mounting position of the LED elements .

The process according to claim according 2, a surface light emitter comprising an electrical wiring by inkjet printing, in addition to the requirements of claim 1, wherein,
The substrate is one to which a flexible material that can be bent or bent is applied,
Further, the substrate is provided with a top film so as to cover the LED element.

The above-described problems can be solved by using the configuration of the invention described in each of the claims.
First, according to the first aspect of the present invention, since the electrical wiring is formed on the substrate by ink jet printing, the degree of freedom in forming the wiring pattern is higher than when forming by silk printing, and any electrical wiring is possible. . In addition, since a plate (silk screen), which was indispensable in silk printing, is not required, the cost can be reduced, and it is possible to deal with one-point items such as prototypes (in the case of silk printing, ordering in a lot (usually , A minimum of 100) was common). Moreover, the delivery time can be shortened remarkably, and if it is a simple one, it can respond on the same day. Incidentally, in the case of silk printing, a delivery time of about one month was required.
In addition, when the surface light emitting body obtained by the present invention is applied to an internally illuminated signboard (box character signboard), a beautiful signboard with no dots and light unevenness due to LED elements can be obtained, and a high-quality decoration effect can be obtained. can get.
In addition, it is possible to produce electric wiring, LED mounting, box character signboards in total and in a short period of time only from character data from the user (light emitting surface data).
Moreover, since several LED elements are installed along the outline of the light emitting surface, any light emitting surface can be illuminated uniformly. In other words, since the LED unit that has been modularized in advance has been used for general purposes, even in the case where light unevenness occurs depending on the light emitting surface, the LED according to the shape and size of the light emitting surface is used in the present invention. Since the element installation position and the electric wiring pattern are individually determined (so that the pitch of the LED elements can be changed), the light emitting surface can be illuminated almost uniformly. (So-called on-demand).
It should be noted that the formation of electrical wiring by ink jet printing itself is a technique that can be performed on a conventional substrate premised on modularization, and is extremely effective.

According to the second aspect of the present invention, since the substrate is flexible, it is possible to obtain a signboard (display board) that is extremely thin and curved. That is, for example, a conventional box character signboard often uses a fluorescent lamp or a neon tube as a light source, and therefore has a certain thickness and often protrudes relatively large from the wall surface. Then, the thickness of the signboard can be reduced, and the display portion can be curved.
Further, in the present invention, since the top film is stretched above the LED element, even a surface light emitter alone can provide high waterproofness, dustproofness, etc. For this reason, the surface light emitter is exposed to wind and rain (for example, It can be used outdoors, indoors, and in bathrooms where water is splashed, and can be used for a wide range of applications (not limited to the use of internally illuminated signboards).

It is the perspective view (a) which shows the internally-illuminated signboard (box character signboard) which incorporates the surface light emitter which concerns on this invention, and sectional drawing (b) which shows the internal structure of this internally-illuminated signboard skeleton. It is explanatory drawing which shows an example of the process until the arrangement | positioning of an LED element is determined in the box character signboard of "a" shown to Fig.1 (a). It is explanatory drawing (a) which shows the installation position (mounting position) of an actual LED element, and explanatory drawing (b) which shows an example of the electrical wiring according to this position same as the above. It is explanatory drawing which shows the vacuum pressure bonding method at the time of sticking and tensioning a top film on a board | substrate (LED element) in steps. A perspective view (a) showing a conventional LED type box character sign (uppercase letter “R”), and a perspective view (b) showing a basic configuration of the AA ′ line and the BB ′ line cross section of the figure. It is sectional drawing (c) which shows the internal structure of a signboard. An explanatory diagram (a) showing an example of mounting when a modularized LED unit is used for a surface light emitter having an equilateral triangular light emitting surface, an example of appearance at the time of lighting, and the light emission It is explanatory drawing (b) * (c) which shows two types of mounting examples of the preferable LED element in a surface. An explanatory diagram (a) showing an example of mounting when a modularized LED unit is used for a surface light emitter having a circular light emitting surface, an example of appearance at the time of lighting, and the light emitting surface It is explanatory drawing (b) which shows the example of mounting of the preferable LED element in.

The mode for carrying out the present invention includes one described in the following embodiments, and further includes various methods that can be improved within the technical idea.
In the description, first, the surface light emitter 1 according to the present invention will be described, and thereafter, characteristic matters (the present invention) for manufacturing the surface light emitter 1 will be described. The internally illuminated signboard SB incorporating the body 1 will be described.

  As shown in FIG. 1B as an example, the surface light emitter 1 according to the present invention includes a substrate 11 having an electrical wiring 12, a plurality of LED elements 13 arranged on the substrate 11, and the LED elements 13. It comprises a top film 14 stretched from above the attached substrate 11. Here, the signboard shown in FIG. 1 (a) shows an internally illuminated signboard SB (particularly a box character signboard) in which the surface light emitter 1 according to the present invention is incorporated. Here, lowercase letters “a”, “ m ”... FIG. 1B is a cross-sectional view in which the vicinity of the center of the box character signboard “a” is vertically divided. Hereinafter, each member constituting the surface light emitter 1 will be described.

  First, the substrate 11 will be described. The substrate 11 serves as a base member to which a plurality of LED elements 13 are attached (mounted), has a film shape or a sheet shape, and has various insulating properties and flexible properties (curved or bendable properties). The material can be applied. In particular, in this embodiment, a material that is excellent in flexibility and can be freely curved is applied. Examples of such materials include plastics (synthetic resins) from the viewpoint of convenience of handling and ease of processing. Particularly, polyethylene terephthalate, polyester, polyimide having excellent heat resistance, light resistance, mechanical strength, etc. It is desirable to apply vinyl chloride, epoxy resin, etc. Among them, white PET film is applied in this embodiment.

In addition, as described above, the substrate 11 is provided with the electric wiring 12 for energizing the LED element 13 and lighting and blinking the LED element 13, and in the present invention, this is formed by ink jet printing. .
Here, the ink jet printing is a method of forming an appropriate wiring pattern (electrical wiring 12) by ejecting conductive ink from a nozzle to the substrate 11 (before the electric wiring 12 is formed). In the past, it was common to form the electrical wiring 12 on the substrate 11 by silk printing (screen printing). However, the silk printing passes the conductive paint only at a desired portion (a portion of the electrical wiring 12). Therefore, there is a drawback that the degree of freedom in forming the wiring pattern is low. In addition, since a plate (silk screen) is required, the cost is high, and the order is usually set to the minimum in units of lots (minimum of 100 sheets). In this respect, in the present invention, since it is a technique by ink-jet printing, any wiring pattern is possible, and since a plate is not required, the cost can be reduced and a single item can be sufficiently handled. In addition, in inkjet printing, a simple wiring pattern can be manufactured on the same day (usually one month for silk printing). In addition, with inkjet printing, it is possible to produce a total of wiring, LED mounting, and box character signboards using only character data from the user.

  Conventionally, the LED elements 13 'are generally installed at the same pitch both vertically and horizontally (uniform installation). In other words, conventionally, for example, 12 LED elements 13 'are arranged vertically and horizontally, that is, 12 x 12 rows (144 pieces) of LED units are basically set, and 12 x 2 rows (24 pieces). ), 12 × 3 rows (36), 12 × 4 rows (48), 12 × 5 rows (60), 12 × 6 rows (72) LED units are standardized For this reason (so-called modularization), it has become common to construct them by combining them appropriately for each signboard in the field. Since only several types of LED units by modularization can cope with various signboard sizes on the spot, the workability is very good and the versatility of the surface light emitter 1 ′ is enhanced. However, while such convenience is achieved, the modularized LED unit may not be suitable for a box character signboard having a different light emitting surface shape and size in terms of appearance at the time of lighting. (See FIGS. 6 and 7). That is, in the case of a box character signboard, the LED elements 13 are preferably arranged along the contour line of the light emitting surface rather than being arranged at the same pitch in both the vertical and horizontal directions. Ink-jet printing in which the mounting position is determined is exactly suitable. Of course, the formation of the electrical wiring 12 on the substrate 11 by ink jet printing is applicable to the substrate 11 premised on the conventional modularization, and is an extremely effective technique.

Next, the LED element 13 serving as a light source will be described. As described above, a plurality of LED elements 13 are arranged on the substrate 11. As the LED element 13, Nichia NSSW100C is applied as an example, and the light emission angle (so-called view angle) is about 60 degrees to about 120 degrees. The LED element 13 is as thin as possible, and preferably has a planar round shape or a square shape (casing shape). In addition, since the LED element 13 may have some color difference depending on the production lot even in the same color, it is preferable to use the LED element 13 in the same lot as the plurality of LED elements 13 used in the same surface light emitter 1.
Further, when mounting the LED element 13 on the substrate 11 on which the electrical wiring 12 is formed, a fixing method (joining method) using soldering or an adhesive can be employed.

  Next, the top film 14 will be described. For example, as shown in FIGS. 1 and 4, the top film 14 covers the LED element 13 in a laminate form on the substrate 11 to which the LED element 13 is attached. It plays the role and purpose of improving the waterproofness and dustproofness of the body 1). Of course, in addition to such a purpose, the top film 14 also serves to protect and strengthen the LED element 13 from external force and sunlight.

As the top film 14, a transparent plastic sheet having excellent permeability is mainly applied, and the material is high in mechanical strength and excellent in weather resistance (water resistance, heat resistance, light resistance, etc.). In addition, those having good processability are preferable, and examples thereof include polystyrene, polyester, vinyl chloride, and ABS. In particular, it is preferable to use a strong adhesive highly stretchable PVC film (100 microns made by Hiroshima Kasei as an example), and this strong adhesive highly stretchable PVC film has no pinholes in the material. It is thought that it contributes greatly to
Furthermore, when the top film 14 is stretched on the substrate 11 (LED element 13), the film is stuck in close contact with the unevenness of the LED element 13, so that air does not enter between the LED element 13 and the top film 14. This specific method will be described later.
In addition, after the top film 14 is stretched on the surface light emitter 1, it is possible to apply a top coating with silicon or resin from the surface, which makes the surface light emitter 1 more waterproof and dustproof. This is a technique that can be used when further enhancement is desired.

Hereinafter, other members used for the surface light emitter 1 will be described.
Since the substrate 11 is flexible (bendable or bendable), the surface light emitter 1 described above may have low rigidity to be incorporated in the internally illuminated signboard SB as it is. Therefore, for example, as shown in FIG. 1B, a reinforcing plate 15 having a thickness of about 0.5 mm can be attached to the surface light emitter 1 (for example, made of aluminum).
Incidentally, in FIG. 1, the reinforcing plate 15 is provided in a flat state, but the holding posture of the substrate 11 (surface light emitter 1) is not necessarily limited to the flat state. For example, the reinforcing plate 15 is attached to an appropriate R surface. By forming it in a shape, the substrate 11 (surface light emitter 1) can also be held in the same posture as the reinforcing plate 15. That is, in terms of a signboard, not only a signboard with a flat display unit 21 as a light emitting surface, but also an internally illuminated signboard SB that is appropriately curved can be obtained.

The surface light emitter 1 has the basic structure as described above, and the characteristic items when the surface light emitter 1 is manufactured will be described below.
(1) Formation of electrical wiring In forming the electrical wiring 12, it is first necessary to determine how the LED element 13 is to be installed (in other words, the mounting status). Basically, based on the contour line of the light emitting surface (display unit 21), an arrangement line (arrangement line of the LED elements 13) along the contour line is assumed. The arrangement line is set in consideration of the shape, the distance from the light emitting surface to the LED element 13 (mounting position), the brightness of the LED element 13 itself, the view angle, and the like. Incidentally, two two-dot chain lines in FIG. 2A show an example of the arrangement lines L1 and L2.

Here, the broken line portion (the portion indicated by the symbol Z) in FIG. 2A is farther from the two arrangement lines L1 and L2 than the other portions, and light unevenness is caused in the portion as it is. It is possible that this will occur. Therefore, here, for example, as shown in FIG. 2 (b), the outer arrangement line L2 is set in a circular shape (double concentric circle) along the inner arrangement line L1, and a portion Z where light unevenness easily occurs is formed. A substantially triangular arrangement line L3 is set to improve the appearance of the portion when it is turned on. Of course, the brightness and the view angle of the LED element 13 are also taken into consideration when changing the arrangement line L2 or assuming the arrangement line L3.
When the actual arrangement position (mounting position) of the LED element 13 is determined along the arrangement lines L1, L2, and L3, for example, as shown in FIG. The wiring 12 is set as shown in FIG. 3B, for example, and a wiring pattern based on this setting is formed on the substrate 11 by ink jet printing. Here, reference numeral 16 in the figure denotes a constant current circuit.

In the present embodiment, the constant current circuit 16 stabilizes the circuit by passing a constant current (for example, 20 mA) through a circuit in which 12 LED elements 13 are connected in series. Therefore, the electric wiring 12 shown in FIG. 3B has a basic structure in which twelve LED elements 13 (connected in series) form one loop and several (here, three rows) are connected in parallel. It is what is taken. Of course, if the configuration of the constant current circuit 16 is changed, the number of series can be changed, and current control for two loops and three loops can be performed by one constant current circuit 16. Furthermore, the rated voltage can be changed.
If it is difficult to arrange, for example, 12 LED elements 13 in one series circuit due to the character shape of the box character signboard (if a uniform pitch cannot be maintained by providing 12), insert a chip resistor. It is preferable to make the resistance applied to one row uniform.
In addition, the electrical wiring 12 is not necessarily limited to such a circuit configuration, and all the LED elements 13 can be connected in series. In this case, depending on the number of the LED elements 13 It is necessary to change the input voltage.

(2) Adhesive Bonding of Top Film Thereafter, in this example, the top film 14 is stretched in close contact with the uneven shape of the LED element 13 mounted on the substrate 11. Specifically, the LED element 13 and the top film 14 are placed in a vacuum state and the film is stretched (vacuum pressure bonding). To perform such vacuum pressure bonding, as shown in FIG. A vacuum pressure bonding device 4 is applied. In addition, this FIG. 4 has shown the construction condition of the vacuum pressure bonding clearly, and the scale of the board | substrate 11 with which the top film 14 is stretched, the LED element 13, etc., and the vacuum pressure bonding apparatus 4 is not the same. Further, in this specification, “stretching (top film 14) in close contact” means sticking so that air does not enter between LED element 13 and top film 14. Hereinafter, the vacuum pressure bonding device 4 will be described.

The vacuum pressure bonding apparatus 4 shown in FIG. 4 is a kind of so-called “Next Generation Forming (NGF)”, and is provided with a pair of upper and lower sealable boxes. Here, the upper box is 41A, the lower box is 41B, the upper box 41A is opened at the lower side, while the lower box 41B is opened at the upper side, and the upper and lower boxes 41A and 41B are brought into contact with each other. When this occurs, the inside becomes a sealed space across the top film 14 to be stretched. Here, the sealed spaces formed in each box are 41AR and 41BR, respectively.
The upper box 41A is formed such that the box itself can move up and down, and an electric heater 42 is built in the box. Furthermore, although the lower box 41B is formed in an immobile state, an elevating table 43 that can move up and down is provided therein. Here, in the figure, reference numeral 44 is a pneumatic tank, reference numeral 45 is a vacuum tank, and reference numeral 46 is a switching valve.
Hereinafter, an operation mode in which the top film 14 is stretched in close contact with the substrate 11 by the vacuum pressure bonding device 4 will be described.

[1] Preparatory work The following preparatory work is carried out prior to the actual film tensioning work. First, as shown in FIG. 4A, the substrate 11 with the LED element 13 attached (this is referred to as an intermediate product 1a) is placed on the lifting table 43 in the lower box 41B that is in the separated and open state. . At this time, the LED element 13 is set with its surface facing upward.
Next, the upper side of the lower box 41B is set so as to be covered with the top film 14 held by the frame F.

[2] Heating (vacuum)
Thereafter, as shown in FIG. 4B, the upper box 41A is lowered and the top film 14 is sandwiched between the upper and lower boxes 41A and 41B. In this state, independent sealed spaces 41AR and 41BR are formed in the upper and lower boxes 41A and 41B with the top film 14 interposed therebetween. Further, after the switching valve 46 is operated so that the vacuum tank 45 also acts on the sealed space 41AR, both the sealed spaces 41AR and 41BR are simultaneously brought into a vacuum state.
Then, after both the sealed spaces 41AR and 41BR reach a certain degree of vacuum, the electric heater 42 in the upper box 41A is operated to heat the top film 14.

[3] Primary molding When the top film 14 reaches a desired molding temperature by heating (a temperature at which the elongation of the film reaches the maximum is desirable), as shown in FIG. 4 (c), ascending and descending in the lower box 41B The table 43 is raised and primary molding is performed. In this primary molding, the top film 14 is attached to the upper surface of the LED element 13 which is the highest position (top surface) of the intermediate product 1a as illustrated.

[4] Secondary molding Next, the vacuum is released only inside the upper box 41A (sealed space 41AR). For this purpose, as shown in FIG. 4D, the switching valve 46 is operated to switch the sealed space 41AR to an open state, and then the atmosphere is introduced into the upper box 41A in the atmospheric pressure state. To. At this time, since the space in the lower box 41B, that is, the space below the top film 14 where the intermediate product 1a exists is still in a vacuum state, the upper and lower sides of the top film 14 are changed by the atmospheric pressure introduced into the upper box 41A. The top film 14 is pressed against the intermediate product 1a due to the pressure difference formed on the substrate 11 and securely adheres to the joint portion or corner portion of the substrate 11 and the LED element 13.

  As described above, in this embodiment, the film is stretched between the top film 14 and the intermediate product 1a, that is, with the top film 14 as a boundary, the space on the intermediate product 1a side to which the top film 14 is pressed is evacuated. Therefore, air does not enter between the film and the LED element 13. Moreover, since the top film 14 is heated at the time of tensioning, the film stretches well and wrinkles do not occur, and the top film 14 can be brought into close contact with the uneven shape of the LED element 13. Moreover, since there is no air intrusion between the film and the LED element 13, the LED element 13 is not easily affected by heat from the outside during use of the finished product. In other words, if air has entered between the film and the LED element 13, the air trapped by the heat of the LED element 13 or the like expands during use of the finished product, and the LED element 13. However, in this embodiment, there is no concern about this in order to prevent air from entering.

(3) Applying a strong adhesive highly stretchable PVC film as the top film In the present embodiment, it is preferable to apply a highly adhesive highly stretchable PVC film (100 microns made by Hiroshima Kasei as an example) to the top film 14. In combination with the vacuum pressure bonding method, the top film 14 can be brought into almost complete contact with the uneven shape of the LED element 13. That is, since the top film 14 is a thick film and has excellent stretchability, the top film 14 is suitable for the vacuum pressure bonding in which the film is applied at a high elongation rate, and is sufficient for the uneven shape of the LED element 13. It can be made to adhere to.

  Moreover, since the said strong adhesion highly stretchable PVC film does not have a pinhole in a raw material, it is thought that this has contributed greatly to waterproofness improvement. That is, since there is no pinhole in the film, water penetration (permeation) from the outer surface to the LED element 13 side can be prevented at a high level after stretching, and this is considered to significantly improve waterproofness. . Incidentally, in a test conducted by the present applicant, it was confirmed that water immersion was not observed even after 4 months after the surface light emitter 1 stretched with the film was stretched, and high waterproofness was exhibited. . For this reason, the surface light emitter 1 is not housed in the signboard case 2 or the like, and can be installed in an outdoor state or a place where water is splashed (for example, a wall surface of a bathroom). In addition, a wide range of applications is possible, and a wide variety of surface light emitters 1 can be developed.

  The top film 14 (strongly adhesive high stretch PVC film) obtained the waterproof standard “IP58” defined by the JIS standard and the IEC standard (IEC stands for International Electrotechnical Commission and indicates the International Electrotechnical Commission). Is. “5” of “IP58” means “grade 5” of the first characteristic number, and indicates a protection grade for solid matter, that is, a so-called “dustproof” protection grade. By the way, this “5th grade” means that “dust that causes harmful effects does not enter (dust-proof type)”. In addition, “8” of “IP58” means “8th grade” of the second characteristic number, and indicates a protection degree against water. As for the resistance level against water, 0 to 8 grades are defined. If the grade is up to 6th grade, there is a possibility of inundation inside, and the 8th grade shows the highest level of “waterproof”. By the way, “waterproof grade 8” means that “even if it is continuously submerged, it will not be submerged inside (underwater type)”.

  In addition, the surface light emitter 1 of the present example conforms to the RoHS directive, and “RoHS” is an acronym for “Restriction of Hazardous Substances” and is included in electric and electronic devices. It means the European Parliament and Council Directive on restrictions on the use of certain hazardous substances.

Next, an internally illuminated signboard SB in which such a surface light emitter 1 is incorporated as a light source (light emitter unit), particularly a box character signboard will be described. Here, the box character signboard is a three-dimensional character signboard having a hollow (box shape) inside. In particular, in this embodiment, a signboard that emits a character portion is assumed. Here, “characters” include not only hiragana, katakana, kanji, alphabets, but also figures, symbols, figures such as triangles and circles, marks and figures representing companies, organizations, brands, etc. It is a waste. In other words, the “character” here usually has a shape or size that differs depending on the individual signboard. Therefore, when a conventional modularized LED unit is used, light unevenness is likely to appear. It means that.
An internally illuminated signboard SB (box character signboard) having such a light emitting surface is placed in a signboard case 2 composed of a display section 21, a side section 22 and a back section 23 as shown in FIG. The surface light emitter 1 is accommodated, and it is considered that the surface light emitter 1 is not directly exposed to wind and rain.

The display unit 21 is a light emitting surface that substantially displays an advertisement or information, is formed in a suitable character shape, and can be said to be a front surface of the signboard case 2. The back surface portion 23 is a surface opposite to the display portion 21 and is a portion that fixes and supports the surface light emitter 1 in the case, while the outside of the case is attached to an outer wall surface of a building or the like. Further, the side surface portion 22 is a portion that connects the periphery of the display portion 21 and the back surface portion 23.
Here, in this embodiment, the surface light emitter 1 is attached so that the LED element 13 (light emission side) faces the display unit 21, and the light emitted from the surface light emitter 1 (LED element 13) is directly reflected. The light is transmitted through the display unit 21. For this reason, a reflecting plate or the like is not provided in the case, so that the structure as a signboard is simplified, and the thickness of the internally illuminated signboard SB can be extremely thin.

  It is preferable that a fiber sheet (FF sheet) or acrylic in which both sides of a member made of strong fiber are sandwiched (integratedly formed) with a translucent resin layer or acrylic is applied to the display unit 21. In addition, when the view angle of the LED element 13 is about 105 to 110 degrees, if the display unit 21 is an FF sheet, even if the signboard thickness (the thickness of the box character) is about 50 mm or less, from the LED element 13 It has been confirmed by the present applicant that the divergent light can be made uniform and the dots of the LED elements 13 are not visually observed (does not appear).

  If the top film 14 is stretched on the surface light emitter 1 as described above, the surface light emitter 1 alone can be used outdoors or in places where water is splashed. However, the signboard case 2 does not have the side surface portion 22, and the display portion 21 can be provided at an appropriate distance from the surface light emitter 1 attached to the back surface portion 23. In other words, when the top film 14 is not stretched, the outdoor environment accommodated in the signboard case 2 having high waterproofness, or the usage environment in a space (indoor) where there is no risk of water (water vapor) intrusion. It is limited to.

Further, when the substrate 11 is flexible, the surface light emitter 1 according to the present invention can be applied to a signboard in which the display unit 21 is curved or bent.
Furthermore, if the surface light emitter 1 according to the present invention is used as a backlight for a cut character, the thickness of the surface light emitter 1 can be formed extremely thin, so that a clean cut character with no thickness can be produced.
In addition, the surface light emitter 1 according to the present invention has a planar light emission and is excellent in waterproofness and the like, so that uses other than signs (particularly internally illuminated signboards SB) and wall decorations can be considered. It is also conceivable that the surface light emitter 1 is incorporated into a part of a partition, a partition, or the like, or the surface light emitter 1 itself is used as an evacuation guide line or handrail guide regardless of indoors or outdoors.

In the surface light emitter according to the present invention, for example, LED elements can be installed along the contour line of the light emitting surface. Therefore, when the LED elements are installed at the same pitch both vertically and horizontally, light unevenness appears on the light emitting surface. Suitable when it is easy to do. In particular, it is suitable for use as an internally illuminated signboard such as a box character signboard whose light emitting surface has a different shape and size depending on the individual signboard.
In addition, since the surface light emitter according to the present invention can be formed extremely thin, if it is used as a backlight for a cut character, it is possible to produce a clean cut character with no thickness.
Further, when a top film is stretched on a surface light emitter mounted with an LED element (in addition, it is more preferable to apply a top coat such as silicon or resin), the surface light emitter alone is also highly waterproof and dustproof. Since the surface light emitter is exposed to wind and rain, that is, the surface light emitter alone can be used as an indoor / outdoor advertisement display board / information display board.

DESCRIPTION OF SYMBOLS 1 Surface light emitter 1a Intermediate product 2 Signboard case 4 Vacuum pressure bonding apparatus 1 Surface light emitter 11 Substrate 12 Electrical wiring 13 LED element 14 Top film 15 Reinforcement plate 16 Constant current circuit 2 Signboard case 21 Display part 22 Side part 23 Back part 4 Vacuum Crimping device 41A Upper box 41AR Sealed space 41B Lower box 41BR Sealed space 42 Electric heater 43 Lifting table 44 Pressurized air tank 45 Vacuum tank 46 Switching valve R Reflector Z part (part where light unevenness easily occurs)
L1 placement line (for LED elements)
L2 placement line (for LED elements)
L3 placement line (for LED elements)
SB interior-lit signboard

Claims (2)

A substrate with electrical wiring;
In a method of manufacturing a surface light emitter comprising a plurality of LED elements arranged with respect to the substrate,
The electrical wiring is formed on the substrate by inkjet printing ,
Further, among the plurality of LED elements, at least some of the mounting positions are determined from the contour line of the light emitting surface along the assumed arrangement line with a substantially constant interval,
On the other hand, the electrical wiring is formed on the substrate so as to be connected in series according to the mounting position of the LED element, and the method of manufacturing a surface light emitter having electrical wiring by ink jet printing.
The substrate is one to which a flexible material that can be bent or bent is applied,
Also on the substrate, according to claim 1, wherein the top film is provided to cover the LED elements, the method for manufacturing a surface-emitting body comprising an electrical wiring by inkjet printing.

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