JP2004279485A - Light emitting diode display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED display such that characters etc., figured with LED elements are not recognized when turned off. <P>SOLUTION: On a circuit board 41 stored in the LED display 1, a light reflective film 7 formed by silk printing is formed in a dot matrix shape in an area 41a where LED elements 41 are not mounted. In the entire area on the circuit board 41, a pattern in a dot matrix shape wherein LED elements 42 and the light reflecting film 7 are mixed is formed. Even when the LED elements 42 are arrayed to figure characters, the pattern of the dot matrix shape is viewed in the inner side of a case 2 reflected on a panel 3 and the array of LED elements 42 is made hard to be discriminated to prevent false illumination. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an LED display for displaying characters, figures, and the like by turning on a plurality of LED (light emitting diode) elements arranged on a substrate.
[0002]
[Prior art]
In addition, there is a display device that displays characters, figures, and the like using a light emitting element such as an LED as a light source. The LED display displays a character, a figure, etc. from the whole display by arranging a plurality of LED elements appropriately and controlling lighting and extinguishing of each LED element. The LED display is used for alerting, guiding, guiding, and the like to the surrounding people such as the user through the display. For example, it is installed in factories, production lines, and facilities to indicate material shortages or mechanical failures, and is also used in vehicles such as road vehicles to indicate that work is in progress. . In recent years, it has been used to display warning characters according to an emergency in the case of being installed on a rear wall surface of a vehicle body so as to call attention to a nearby vehicle or the like.
[0003]
In the case where a small number of characters or figures to be displayed are specified, it is sufficient to prepare only the LED elements corresponding to the display. Therefore, the LED elements are arranged on the board in a pattern of one character or one figure. There is a specification to make it. According to this specification, characters are illuminated on a display in a manner similar to the arrangement of LEDs by simultaneously illuminating LED elements mounted in predetermined sections on a substrate. Even when there are a plurality of characters, figures, and the like to be displayed, it is possible to mount the LED elements on the board so that they are overlapped in the same section and to switch and display the switching elements via switching means such as switches.
With these specifications, the number of LED elements to be prepared can be reduced to the minimum source compared to the specification in which LED elements are arranged and arranged in a matrix so as to correspond to many display patterns, and a complicated control circuit and the like are separately prepared. No need. As a result, the cost is reduced, the weight of the product is reduced, and the maintenance is improved by simplifying the structure.
[0004]
[Patent Document 1] JP-A-2002-225626
[0005]
[Problems to be solved by the invention]
By the way, in this type of LED display, a structure in which the LED element is exposed to the outside and appears on the display, or a translucent panel is arranged facing the arranged LEDs, and the LED element is exposed to rainwater from outside. It is broadly divided into those that prevent from dust and dust.
In any of the configurations, since the LED element is used as a medium to display characters and the like, such an LED element is visually recognized from the outside. In such a case, even when the LED element is not turned on, the LED element is visually recognized by external light. In particular, in the display using the LED elements, the background of the arranged LED elements is darkened such as black to increase the contrast with the light of the LED elements, thereby compensating the light quantity of the LED elements and securing the visibility. It is common. Therefore, the three-dimensional appearance of the LED element is highlighted in the background of the dark color, and the presence of the LED element can be sufficiently recognized even without lighting.
In such a configuration, not only the existence of the LED elements but also the arrangement thereof can be visually recognized. Therefore, if the specification resembles the characters described above, even if the LED elements are not turned on, the characters and the like are visually recognized from the outside in the arrangement of the LED elements, and there is a possibility that pseudo lighting may occur.
[0006]
Therefore, a specification has been conceived in which the surface of the panel is clouded to make the LED elements inside the case difficult to see.However, in this configuration, if the degree of clouding is too large, the light transmission of the LED elements is blocked, and sufficient visibility is obtained. In addition, it cannot be used in specifications without a panel. There is also a method of applying a silicon agent or the like on the substrate on which the LED elements are mounted to coat one surface, making the arrangement of the LED elements difficult to see, but in this case, a large amount of silicon agent must be prepared. In addition, it takes time and labor to dry the silicone agent, and as a result, the product becomes expensive.
Then, an object of the present invention is to solve the above-mentioned technical problem and to provide an LED display that does not give a false recognition when the light is turned off.
[0007]
[Means for Solving the Problems]
An LED display according to claim 1 for achieving the above object, is an LED display in which LED elements are appropriately arranged and mounted on a substrate supported inside a case so as to form characters, figures, or symbols. A light-reflecting film on the surface of the substrate outside the area where the LED elements are mounted, at equal intervals in dot unit size of the visible LED elements, and And a dot matrix pattern composed of an LED element and a light reflection film is formed.
[0008]
According to the present invention, by applying the light reflection film in dot units on the substrate surface outside the area where the LED elements are mounted, a dot matrix shape is formed on the substrate by combining the LED elements and the light reflection film. The pattern is completed. For this reason, even when the LED elements are arranged so as to form characters, figures, symbols, or the like, the viewer can visually recognize an orderly pattern in a dot matrix shape. Therefore, even when the LED elements are not turned on, the LED elements are not misidentified by the arrangement of the LED elements. If the size of the light reflecting film is set to the size of the dot of the LED element to be visually recognized, it is difficult to distinguish it from the LED element, and the effect of preventing erroneous recognition is improved. In addition, since the light reflection film is not applied to the area where the LED element is mounted, the LED element is mounted as designed by finding a vacant place in the dot matrix pattern formed after mounting the LED element. You can check if you have done. Therefore, the mounting of the LED element can be easily confirmed at the time of manufacturing. Furthermore, since the effect of preventing false lighting can be exhibited only by providing a light reflection film on the substrate, it can be performed at low cost and is economically preferable.
[0009]
According to a second aspect of the present invention, there is provided an LED display in which LED elements are appropriately arranged and mounted on a substrate supported inside a case so as to form characters, figures, or symbols. A light reflection film is provided on the upper surface of the LED element in a dot matrix in a size of a dot unit of the visible LED element, and the LED element is appropriately mounted facing the applied light reflection film.
According to the present invention, by mounting the LED element on the light reflecting film, the light reflecting film reflects the irradiation light leaking to the bottom surface of the LED element and emits the light to the outside. For this reason, the amount of light to be radiated to the outside increases, and the light becomes brighter, and the visibility can be improved without applying a special load to the LED element. In addition, since the light reflection film is applied in a dot matrix on the visible substrate, the dot matrix pattern is lost on the substrate even if the LED elements are mounted so as to form characters later. There is no. For this reason, it is also effective in preventing false recognition when the light is turned off.
In practicing the present invention, it is preferable that the light reflection film is formed by silk printing of white or a color similar thereto, as described in claim 3. By this silk printing, light leaking to the bottom surface of the LED element or the like can be reflected forward to enhance visibility. In addition, silk printing can be performed on a substrate in a single printing, which contributes to a reduction in manufacturing time and cost.
BEST MODE FOR CARRYING OUT THE INVENTION
[0010]
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external front view (a) and a side sectional view (b) of an LED display according to an embodiment of the present invention.
As shown in FIG. 1, the LED display 1 is configured by housing an LED (light emitting diode) element serving as a light source and a control mechanism thereof inside a case 2 forming an outer shape. The LED display 1 is attached to a wall surface of a vehicle body, a building, equipment, or the like, and displays characters, graphics, and the like from a display surface in front of the case through irradiation light from the LED elements. Although the overall shape of the LED display 1 varies depending on the rows and columns of characters and the like to be displayed, the present embodiment takes up and describes a specification in which a plurality of characters are vertically arranged to display a single character string.
[0011]
The case 2 is configured by combining a front case 21 provided with an opening for forming a display surface, and a plate-shaped rear case 22 disposed facing the front case 21. The front case 21 and the rear case 22 are both formed by processing a resin material such as plastic or a sheet metal, and are formed of a non-light-transmitting material so as not to transmit irradiation light from a light source to be accommodated. Process such as coloring. Thus, the LED display 1 is configured such that light from the light source does not pass through portions other than the opening. When the case 2 is darkened, the contrast between the light emitted from the light source and the light emitted from the light source becomes clear, and the displayed characters and the like appear more clearly, which is effective.
[0012]
The display surface is formed by fitting the panel 3 into the opening 21 a of the front case 21. The panel 3 is a plate-shaped member made of a light-transmitting material such as methacrylic resin and glass resin. The panel 3 may be colorless and transparent, but if the surface facing the inside of the case 2 is textured on one or all sides, the degree of transmission may be appropriately suppressed. In other words, the pattern inside the case projected on the panel becomes difficult to see, which leads to prevention of false lighting, while keeping necessary and sufficient visibility. In order to fit the panel 3 into the front case 21, various methods such as applying an adhesive (not shown) to the periphery of the panel 3 fitted in the opening and fixing the panel 3 in addition to forming fitting means in each case are used. Method. In addition, by giving the panel 3 a function as a lens, the area of characters and the like to be displayed by diffusing the light of the LED element 42 can be increased.
The rear case 22 can fix the circuit board 41 on which the LED elements 42 are appropriately arranged, attach the opposite side of the surface on which the circuit boards are arranged to a wall surface, and mount the LED display 1 via a screw mechanism. . The screw mechanism includes a bolt 62 having a shaft, and a nut 63 screwed into the shaft via a washer 64 to be fastened. The screw mechanism is provided above and below the case 2. In mounting on the wall surface, the bolt 62 is inserted through the rear case 22, the shaft portion protruding to the rear surface of the rear case 22 is inserted through the surface to be mounted, and the washer 64 and the nut 63 are assembled and fastened. .
A cabtire wiring 51 for connecting to the circuit board 41 is inserted through the center of the rear case 22, and is wired to the circuit board 41 via a connection terminal such as a connector 43.
The inserted cabtire wiring 51 is subjected to a retaining process such as a cable tie 52, and a sealing agent 53 for waterproof is applied from the inside of the case 2 so as to fill a gap with the inserted hole. Prevent water intrusion.
The front case 21 and the rear case 22 are combined with each other via fitting means provided, and are fastened by inserting male screws 61 from above and below and from the left and right on the rear case 22 side.
In FIG. 1, a joining piece 21b is provided on the peripheral edge of the front case 21, and a peripheral wall groove 22b is provided on the corresponding rear case 22 along the peripheral edge. By combining the front case 21 and the rear case 22, the joining piece 22b fits into the recess of the peripheral wall groove 21b and is joined. The circuit board 41 fixed to the rear case 22 is accommodated in a closed space formed by combining the front case 21 and the rear case 22.
[0013]
The circuit board 41 has a plate shape, and the surface on the side where the LED elements 42 are mounted is colored in a dark color such as black. This is because the circuit board, which is the background of the illuminating LED element, is darkened so that the illuminating light can be seen more clearly. The circuit board 41 is arranged on a plurality of screw holes 22a formed at predetermined positions of the rear case 22, and is fixed to the rear case 22 by screwing. A plurality of LED elements 42 are appropriately arranged on the circuit board 41, and receive power from the connected cabinet wiring 51 to supply power to each LED element 42. By controlling the supplied pattern, the light emission of the LED element 42 can be controlled.
[0014]
2A and 2B are diagrams illustrating a process of mounting the LED element 42 on the circuit board 41, wherein FIG. 2A illustrates a state before mounting, and FIG. 2B illustrates a state after mounting. The characters to be displayed vary widely depending on the use of the LED display, but in this embodiment, they are attached to the rear of the vehicle body such as a shared bus, and are notified to the outside when an emergency such as a bus jack or a fire occurs. An emergency display LED display used for this purpose will be described. According to this specification, in the event of an emergency, an emergency operation switch (not shown) installed near the driver's seat is turned on, so that the LED display attached to the rear of the bus body displays "SOS" Is displayed.
[0015]
In FIG. 2, a required number of LED elements 42 are prepared so as to follow the characters "S", "O", and "S". On the corresponding circuit board 41 side, a mounting hole (not shown) for mounting to face the arrangement of the LED elements 42 is formed at a predetermined location. In the area 41a where the LED element 42 is not mounted, the circular light reflecting film 7 is formed in a dot matrix. The size of the light reflection film 7 may be determined according to the size of the visible LED element 42 in units of dots. In the present embodiment, the LED elements 42 used are substantially bell-shaped, and the LED elements 42 mounted on the circuit board 41 are visually recognized as a continuous form in units of circular dots. The size of the light reflecting film 7 is determined according to the size of the circle. Therefore, if the LED elements used are square, the light reflection film 7 may be formed in square dot units. In this way, by applying the light reflecting film in accordance with the size of the LED element to be visually recognized, after mounting the LED element 42, the surrounding light reflecting film 43 becomes indistinguishable, and the prevention of false lighting is improved. can do.
[0016]
The light reflection film 7 includes a light reflection member in a material, and includes, for example, silk printing that is performed using ink containing particles such as metal. Silk printing has a property of reflecting light when it is hit, and a light reflecting film can be applied to the entire area on a circuit board in a single process, which leads to a reduction in manufacturing time and cost. Although the silk printing is drawn as a circle painted in light black in FIG. 2 (similarly in FIG. 3), in practice, white or a similar color is used. By making the color white, it is possible to approximate the transparent color of the mounted LED element 42, and it is also sufficiently visible even with a small amount of light, and it is efficient in improving the brightness of the dot matrix pattern LED element. desirable. The light reflection film 7 can be applied by silk-screen printing on the circuit board 41 processed into a dark color.
[0017]
When the LED elements 42 are mounted, as shown in FIG. 2B, a pattern having one surface formed in a dot matrix is formed on the circuit board 41. This pattern is formed by mixing the mounted LED element 42 and the light reflection film (silk printing) 7 formed on the circuit board 41. The front case 21 covers the circuit board 41 and is combined with the rear case 22. At this time, the above-described dot matrix pattern is projected on the panel 3 in the front case 21. For this reason, when the lights are turned off, the viewer recognizes that there is a dot matrix pattern on the panel 3. That is, since the characters (“S”, “O”, and “S”) in the form of the arranged LED elements 42 cannot be read, a person who looks at the LED display 1 such as a driver of a vehicle behind the vehicle in a normal situation where the LEDs do not light up. In addition, there will be no need to rescue people in an emergency.
Further, as shown in FIG. 2A, the area 41b on the circuit board 41 where the LED elements 42 are arranged is not subjected to silk printing. Therefore, when the LED element 42 is not mounted, the surface of the circuit board remains in the state of FIG. 2B.
Then, since the periphery is a dot matrix pattern, it is easy to confirm whether or not the LED element 42 is mounted as designed by finding an empty portion in the pattern at the time of manufacturing.
[0018]
3A and 3B show a second embodiment, in which FIG. 3A shows a state before the LED element 42 is mounted, and FIG. 3B is an enlarged view of a main part in a state in which the LED element 42 is mounted. FIG. In the second embodiment, the light reflection film (silk printing) 7 is applied to the entire area on the circuit board 41. When the LED elements 42 are mounted on the circuit board 41, a dot matrix pattern is completed similarly to the one shown in FIG. At this time, in a place where the LED element is mounted, as shown in FIG. 3B, the LED element 42 is arranged on the light reflection film 7. Then, while irradiating directly from the LED element 42 toward the panel 3 on the front side, light leaking to the bottom surface of the LED element 42 and the like is reflected and illuminated on the light reflection film 7 located on the lower surface. Therefore, the luminance of the irradiation light is increased as a whole, and the visibility is improved. Therefore, the light source light can be used effectively.
In FIG. 3B, the LED element 42 is mounted while being slightly floated on the circuit board 41, but the present invention is not limited to this, and the LED element 42 is mounted so as to come into contact with the circuit board 41. You can do anything. The characters to be displayed are not limited to “S”, “O”, and “S”, and characters such as “under boarding” and “110”, as well as figures and symbols can be used. Furthermore, even in a specification in which a plurality of character strings are switched and displayed on the same screen, such as a specification in which switching between "getting on and off" and "SOS" is displayed, if one of the superposed character strings can be read, The present invention can be used without being mistaken.
[0019]
FIG. 4 is a diagram showing a pattern of the light reflection film (silk printing) 7 to be formed, and each of them is a plan view of the light reflection film 7. The dotted line in each figure indicates the region of the light reflecting film, and a pattern not including the dotted line is actually formed.
In addition, the solid lines and black regions depicted in the drawings indicate regions where the light reflection film 7 is not applied, and the ground on the surface of the circuit board 41 appears.
As the pattern of the light reflecting film 7, for example, the methods (a) to (c) can be cited, all of which are for showing the three-dimensional appearance of the mounted LED element 42 on a plane. FIG. 4A shows a shape of the light reflection film 71 formed by penetrating a radial line 71a around a circle. In this case, the three-dimensional effect of the LED element 42 is expressed by using the line 71a. By applying the line 71a radially, an effect of giving an impression as if there is a protruding object on a plane is provided. Similarly, the light reflection film 72 shown in FIG. 4B using lines has a shape in which a circular line 71b appears at the center with the shape of FIG. In this case, the LED element 42 is formed according to a form having a semi-spherical tip such as a generally bell-shaped shape, and the contour of the tip or the like is expressed as a line.
The light reflection film 73 shown in FIG. 4C shows a shape obtained by adding a triangular cutout 73a to a circular square. In this shape, the shadow appearing in the three-dimensional appearance of the LED element 42 is represented by a surface, and the three-dimensional appearance of the LED element 42 is represented by a form in which the black area expands toward the periphery.
As described above, various shapes of the light reflecting film 7 can be cited, but not limited thereto. Other patterns, such as a shape provided with a pattern, are also conceivable.
[0020]
Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various design changes can be made within the scope of the present invention. For example, besides silk printing, it is also possible to take measures such as bonding a film-like material onto a circuit board, spraying a paint having a light-reflective material, or embedding a light-reflecting member on the circuit board. A similar effect can be obtained with a device incorporating a structure. Also, as for the color of the light reflection film, if an optimal color is selected according to the LED element to be mounted, the effect of preventing false lighting can be obtained. Furthermore, since it is sufficient that the light reflection film can be visually recognized in a dot matrix shape in a region that is visually recognized from the outside, it is also possible to minimize the area where the light reflection film is applied, instead of the entire area of the circuit board. In addition, even in a specification in which the LED element to be mounted is covered with a dome-shaped lens, the light reflecting film may be applied so as to resemble the shape of the visible lens, and the shape of the light reflecting film is limited to the LED element. Not something.
In addition, various forms may be adopted for the shape of the LED display, the characters to be displayed, and the like, depending on the intended use.
[Brief description of the drawings]
FIG. 1A is an external front view of an embodiment of the present invention, and FIG.
FIGS. 2A and 2B are diagrams showing an assembling process according to an embodiment of the present invention, wherein FIG. 2A is a diagram before mounting and FIG.
FIGS. 3A and 3B are views showing an assembling process according to a second embodiment of the present invention, wherein FIG. 3A is a sectional view of a main part before mounting, and FIG.
FIG. 4 is a view showing an embodiment of a light reflection film (silk printing) in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 LED display 21 Front case 22 Rear case 3 Panel 41 Circuit board 41a Area in which LED element is not mounted 41b Area in which LED element is mounted 42 LED element 7 Light reflection film (silk printing)

Claims (3)

An LED display in which LED elements are appropriately arranged and mounted on a substrate supported inside the case so as to form characters, graphics, or symbols,
On the substrate surface outside the area where the LED elements are mounted, apply a light reflection film at equal intervals in dot unit size of the visible LED elements,
An LED display, wherein a dot matrix pattern composed of an LED element and a light reflection film is formed over an entire area on a substrate which is visually recognized from the outside. An LED display in which LED elements are appropriately arranged and mounted on a substrate supported inside the case so as to form characters, graphics, or symbols,
On the surface of the substrate, apply a light reflection film in a dot matrix shape with the size of the dot unit of the visible LED element,
An LED display, wherein the LED element is appropriately mounted facing the applied light reflection film. The LED display according to claim 1, wherein the light reflection film is formed of white or a silk print of a color similar to white.

Images