JP6846877B2 - Display unit device and display device - Google Patents

Description

The present invention relates to a display unit device and a display device.

Since the display device displays an image, it is installed in various places regardless of whether it is indoors or outdoors. As such a display device, a device in which a plurality of display unit devices are arranged in a tile shape to form a display screen is widely used.

As a display unit device, a device in which a plurality of light emitting devices are mounted on a circuit board is known. As the light emitting device, a device having a base member provided with a recess, mounting a light emitting element such as an LED on the bottom surface of the recess, and sealing the periphery of the light emitting element with a sealing member is widely used. Such a light emitting device is physically and electrically connected to the wiring formed on the circuit board.

Conventionally, as the base member of such a light emitting device, one made of white resin has been used (see, for example, Patent Document 1). Therefore, the outer peripheral surface of the base member is generally white.

By the way, in order to protect the wiring or the like exposed to the outside, the display unit device is provided with a protective unit for preventing rainwater or the like from entering. For example, it is known that a light emitting device and a mounting surface of a circuit board on which a light emitting device is mounted are integrally sealed by a protective portion (see, for example, Patent Document 2). According to such a method, the light emitting device and the circuit board on which the light emitting device is mounted can be sealed with a simple configuration.

Japanese Unexamined Patent Publication No. 2011-211032 (see paragraph [0022], FIG. 2). Japanese Unexamined Patent Publication No. 2016-12070 (see paragraph [0017], FIG. 2)

Since the outer peripheral surface of the base member constituting the light emitting device is white, the reflectance to ambient light such as sunlight and lighting is high, and the ambient light is likely to be reflected or scattered.
Further, in the wiring formed on the circuit board, the metal member is exposed to the outside. Since such a metal member has a high reflectance to ambient light, the ambient light is likely to be reflected or scattered as in the outer peripheral surface of the base member.

In particular, when the light emitting device and the mounting surface of the circuit board are integrally sealed with a protective portion, a protective portion made of a highly translucent resin material is used in order to efficiently extract the light emitted from the light emitting element. Often done. When such a protective unit is used, ambient light such as sunlight is reflected by the wiring formed on the circuit board and the outer peripheral surface of the base member, so that there is a problem that the contrast of the image is lowered.

The present invention has been made to solve the above-mentioned problems, and is a display unit device and a display device capable of suppressing reflection of ambient light more than before and improving the contrast of displayed images more than before. The purpose is to obtain.

The display unit device according to the present invention includes a circuit board, a light emitting device mounted on a mounting surface of the circuit board, and a protective portion for covering the light emitting device and the mounting surface of the circuit board. It has a base member which is a housing which is arranged on the mounting surface of the above and has an open recess, a light emitting element mounted in the recess, and a sealing member which is arranged in the recess and seals the light emitting element. Is formed from a flexible film that absorbs visible light , and is formed on a first coating portion that covers a light emitting surface that is a contact surface between a sealing member and an external space, and around the first coating portion. It has a second coating that is integrally formed with the first coating and is thicker than the first coating, and the light emitting device is arranged on the base member and abuts against the second coating around the first coating. It has a fixing portion for fixing the first covering portion.

According to the present invention, even if ambient light is incident on the display unit device, it is absorbed and attenuated by a protective unit having absorbency for visible light. Therefore, the reflection of ambient light can be suppressed as compared with the conventional case, and the contrast of the image displayed on the display unit device and the display device can be improved as compared with the conventional case.

It is a schematic diagram of the display unit apparatus which concerns on Embodiment 1 of this invention. FIG. 5 is a cross-sectional view of the display unit device of FIG. 1 as seen along the line AA. It is a top view of the light emitting device which concerns on Embodiment 1 of this invention. It is a side view of the light emitting device which concerns on Embodiment 1 of this invention. It is an enlarged sectional view of the protection part which concerns on Embodiment 1 of this invention. It is sectional drawing which looked at the display unit apparatus of FIG. 1 by the arrow AA when the protection part which does not absorb visible light is used. It is BB sectional view of the display unit apparatus of FIG. It is a perspective view of the display device which concerns on Embodiment 2 of this invention.

A mode for carrying out the present invention will be described with reference to the accompanying drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and the duplicated description thereof will be appropriately simplified or omitted. Further, for convenience of explanation, the size of the portion shown in each figure, the proportional relationship of the shape, and the like may be exaggerated.

Embodiment 1.
The display unit device 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 7. In FIGS. 1 to 4, 6 and 7, XYZ coordinates are defined. Assuming that the front surface (display surface) of the display unit device 1 is installed perpendicular to the ground, the left-right direction is the X-axis direction, the vertical direction, that is, the vertical direction is the Y-axis direction, and the X-axis direction and the Y-axis direction. The direction perpendicular to is described as the Z-axis direction. The same applies to other embodiments.

As shown in FIGS. 1 and 2, the display unit device 1 includes a circuit board 4 which is a square flat plate, a plurality of light emitting devices 2 mounted on the mounting surface 11 of the circuit board 4, and mounting the circuit board 4. The wiring portion 5 formed on the surface 11 so as to extend in the X-axis direction and the Y-axis direction, the protection portion 3 arranged so as to cover the mounting surface 11 of the circuit board 4 and the light emitting device 2, and the wiring portion 5. It includes a connected drive IC (Integrated Circuit) (not shown).

The light emitting device 2 is mounted on the mounting surface 11 of the circuit board 4 in a square grid pattern with intervals D such as 8 mm, 10 mm, and 16 mm. The number of light emitting devices 2 to be mounted is typically 64 × 64, 128 × 128, 256 × 256, 128 × 256, or the like.

The circuit board 4 is made of an insulating resin material or the like. The wiring portion 5 is made of a conductor made of a metal such as copper or aluminum.

In such a display unit device 1, the drive IC drives the light emitting device 2, and visible light of an arbitrary color is emitted from the light emitting device 2, so that an image is displayed on the display surface of the display unit device 1.

Next, the light emitting device 2 will be described in detail with reference to FIGS. 2 to 4. The light emitting device 2 in the present embodiment is a so-called 3in1 type light emitting device, and includes three light emitting elements 23r, 23g, 23b and light emitting elements 23r, 23g, 23b, which emit red light, green light, and blue light, respectively. The mounted package 28, the sealing resin (sealing member) 27 that seals the light emitting elements 23r, 23g, and 23b in the package 28, the light emitting elements 23r, 23g, 23b, and the wiring portion 5 are electrically connected, respectively. The leads 25r, 25g, 25b on the positive side, the leads 26r, 26g, 26b on the negative side, and the fixing portion 51 for fixing the protective portion 3 are provided.

The package 28 is a housing made of an insulating white resin material, and includes a recess 29 in which the upper surface 28c opens. In the present embodiment, an example in which the package 28 having the recess 29 as described above is used as the base member will be described. In the package 28, the surface arranged in front of the display unit device 1 is the upper surface 28c, the surface orthogonal to the circuit board 4 is the side surface 28a, and the surface filled with the sealing resin 27 is the inner peripheral surface 28b. Since the recess 29 of the package 28 is filled with the sealing resin 27, the inner peripheral surface 28b does not come into contact with the external space, but the side surface 28a of the package 28 constitutes a contact surface with the external space. As described above, since the package 28 is made of a white resin material, the side surface 28a is white.

The light emitting elements 23r, 23g, and 23b are so-called surface mount type light emitting elements, and are arranged at equal intervals in this order in the Y-axis direction on the bottom surface of the recess 29 formed in the package 28. As the light emitting elements 23r, 23g, 23b, a light emitting diode (LED: Light Emitting Diode), a laser diode (LD: Laser Diode), or the like is used.

These light emitting elements 23r, 23g, and 23b include a pair of electrodes. By loading the light emitting elements 23r, 23g, and 23b on the leads 25r, 25g, and 25b, one electrode is electrically connected to the leads 25r, 25g, and 25b, respectively. The other electrode is electrically connected to the leads 26r, 26g, and 26b by the wire 24, respectively. The leads 25r, 25g, 25b, and the leads 26r, 26g, 26b each extend along the X axis to the side surface 28a at the bottom surface of the recess 29 of the package 28, and extend along the side surface 28a to the bottom surface of the package 28. Further, it bends along the mounting surface 11 of the circuit board 4.

The circuit board 4 is provided with a connecting portion 6 for connecting the leads 25r, 25g, 25b and the leads 26r, 26g, 26b to the wiring portion 5 by soldering using a reflow method or the like. The leads 25r, 25g, 25b and the leads 26r, 26g, 26b are electrically connected to the wiring portion 5 formed on the mounting surface 11 of the circuit board 4 by the connecting portion 6.

The sealing resin 27 protects the light emitting elements 23r, 23g, 23b, leads 25r, 25g, 25b, and leads 26r, 26g, 26b from moisture, dust, and the like. The sealing resin 27 is made of a silicon resin or the like having transparency to the light emitted by the light emitting elements 23r, 23g, and 23b.

The contact surface between the sealing resin 27 and the external space constitutes a light emitting surface 21 from which the light emitted by the light emitting elements 23r, 23g, and 23b is emitted to the outside. In the present embodiment, the light emitting surface 21 is formed in a plane shape parallel to the XY plane.

As shown in FIGS. 3 and 4, the fixing portions 51 are formed at the four corners of the upper surface 28c of the package 28 around the light emitting surface 21. The shape of the fixing portion 51 is conical, and the bottom surface of the cone is joined to the upper surface 28c of the package 28. The top of the fixed portion 51 is formed so as to pass through the top of the package 28 and be higher than the virtual plane parallel to the mounting surface 11 of the circuit board 4. Such a fixing portion 51 is integrally molded with the package 28, or is separately molded and then joined to the package 28.

In such a light emitting device 2, the light emitting intensity of the light emitting elements 23r, 23g, 23b is generated by the electric power independently supplied from the drive IC via the wiring portion 5, the leads 25r, 25g, 25b and the leads 26r, 26g, 26b, respectively. Can be individually adjusted to emit light of any color from the light emitting surface 21.

In the display unit device 1 according to the present embodiment, a protective unit 3 that covers the mounting surface 11 of the circuit board 4 and the light emitting device 2 is arranged.

As shown in FIG. 5, the protective portion 3 includes a thin-walled portion 32 (first covering portion) composed of a recess 31. The thickness of the protective portion 3 is such that the thin-walled portion 32 has a thickness Th1 and the portion other than the thin-walled portion 32 (second covering portion) has a thickness Th2, and the thickness Th1 is smaller than the thickness Th2. It is configured. The recess 31 is formed so that the surface facing the circuit board 4 is open. Such a recess 31 is formed by plastic working such as press working so as to correspond to a position where the light emitting device 2 is mounted on the circuit board 4.

The protection unit 3 has an adhesive layer on the surface facing the circuit board 4, and is formed on the circuit board 4 along the mounting surface 11 of the circuit board 4, the side surface 28a of the package 28, and the light emitting surface 21 of the light emitting device 2. It is arranged so as to be in close contact with the mounting surface 11, the side surface 28a of the package 28, and the light emitting surface 21 of the light emitting device 2. In this way, the protection unit 3 seals the mounting surface 11 of the circuit board 4 and the light emitting device 2 to protect it from rainwater, moisture in the atmosphere, and the like.

The protective unit 3 exhibits a dark color and has an absorption property for visible light. The dark color may be achromatic or chromatic. Further, the protective portion 3 adds a black colorant such as carbon black to a flexible thin film composed of a waterproof resin such as a polyester resin, a polycarbonate resin, an acrylic resin, and a silicon resin. It is realized by doing. The absorption rate for visible light can be adjusted to a desired value by changing the amount of the colorant added.

Next, the reflection of the ambient light incident on the display unit device 1 will be described in detail. As shown in FIG. 6, when the protection unit 3 which does not absorb visible light is used, the ambient light incident on the display unit device 1 is the wiring unit 5 where the metal is exposed, the connection unit 6, and the white color. It is reflected by the side surface 28a of the package 28 to be presented and is emitted to the outside. Such reflected light causes a decrease in contrast of the image displayed on the display unit device 1.

On the other hand, when the protection unit 3 according to the present embodiment is used, as shown in FIG. 2, the ambient light that has reached the display unit device 1 is partially absorbed by the protection unit 3, so that the wiring is performed. Attenuates before reaching the side surface 28a of the portion 5, the connecting portion 6 and the package 28. Further, the ambient light that reaches the wiring portion 5, the connection portion 6, and the side surface 28a of the package 28 and is reflected is also absorbed by the protection portion 3. As described above, when the protection unit 3 according to the present embodiment is used, reflection on the wiring unit 5, the connection unit 6 and the side surface 28a of the package 28 can be suppressed, and the contrast of the display unit device 1 can be improved as compared with the conventional case. it can.

However, since the light emitting surface 21 is covered with the protective unit 3 having absorbency for visible light, the visible light emitted from the light emitting surface 21 is absorbed by the protective unit 3 and attenuated. When the visible light emitted from the light emitting surface 21 is attenuated, the brightness of the image displayed on the display unit device 1 is reduced. In this case, in order to suppress the decrease in the brightness of the image, it is necessary to increase the amount of power supplied to the light emitting elements 23b, 23g, 23b.

However, in the present embodiment, in the protective portion 3, the thin-walled portion 32 having a thickness of Th1 covers the light emitting surface 21, and the portions other than the thin-walled portion 32 having a thickness of Th2 (> Th1) are the wiring portion 5, the connecting portion 6, and the connecting portion 6. It is configured to cover the side surface 28a of the package 28. Therefore, the reflection of ambient light on the wiring portion 5, the connection portion 6, and the side surface 28a of the package 28 is suppressed, but the attenuation of visible light emitted from the light emitting surface 21 is reduced.

By the way, the absorption rate R of the resin with respect to visible light is represented by R = 1-exp (−αL), where α is the absorption coefficient of the resin and L is the thickness of the resin. That is, the absorption rate R of the resin with respect to visible light decreases exponentially as the thickness L decreases. In the present embodiment, by adjusting the thickness Th1 of the thin-walled portion 32 and the thickness Th2 of the portion other than the thin-walled portion 32, the reflection of ambient light on the wiring portion 5, the connecting portion 6 and the side surface 28a of the package 28 is reflected. It can be effectively suppressed and the attenuation of visible light emitted from the light emitting surface 21 can be significantly reduced.

Next, since the thin portion 32 is thin, it may be torn, and a measure for preventing this tear will be described. The thin portion 32 extends to cover the light emitting device 2 which is mounted on the mounting surface 11 of the circuit board 4 and has a shape protruding from the mounting surface 11, but the thin portion 32 may be torn because it is thin. If the protective portion 3 is torn by the thin-walled portion 32, moisture will infiltrate from the protective portion 3 and the mounting surface 11 of the circuit board 4 and the light emitting device 2 cannot be protected. Therefore, in the present embodiment, as shown in FIG. 7, a fixing portion 51 is formed on the upper surface 28c of the package 28, and the fixing portion 51 abuts and is fixed to the protection portion 3 around the thin-walled portion 32. When the thin-walled portion 32 covers the light emitting surface 21, the portion other than the thin-walled portion 32 around the thin-walled portion 32 is fixed by the fixing portion 51, so that the thin-walled portion 32 is suppressed from stretching and the thin-walled portion 32 is not torn. In this way, the protection unit 3 can protect the mounting surface 11 of the circuit board 4 and the light emitting device 2 from moisture.

As described above, according to the present embodiment, the reflection of visible light on the outer peripheral surfaces of the wiring portion 5, the connection portion 6 and the package 28 is suppressed, and the attenuation of the emitted light 22 from the light emitting surface 21 is remarkably suppressed. However, the contrast of the image displayed on the display unit device 1 can be improved as compared with the conventional case.

Further, since the fixing portion 51 fixes the protection portion 3 and prevents the thin-walled portion 32 from being torn, the protection portion 3 can protect the mounting surface 11 of the circuit board 4 and the light emitting device 2 from moisture.

Embodiment 2.
As shown in FIG. 8, the display device 41 is formed by arranging a plurality of display unit devices 1 according to the first embodiment in a tile shape. The display device 41 can configure a display screen of an arbitrary size by increasing or decreasing the number of display unit devices 1 arranged in a tile shape.

The display device 41 is installed outdoors such as a stadium or a wall surface of a building. It can also be installed indoors such as in gymnasiums. The size of the display screen of the display device 41 is arbitrarily determined depending on the size of the stadium, the size of the public space, and the like in which the display device is installed.

As described above, by providing the display unit device 1, the contrast of the image displayed on the display device 41 can be increased.

As the light emitting device 2, a so-called 3in1 type light emitting device 2 in which three light emitting diodes 23r, 23g, 23b are housed in one package 28 is used, but any of the light emitting diodes 23r, 23g, 23b is used in one package 28. You may use the so-called 1in1 type in which one of them is arranged. Alternatively, a light emitting device 2 provided with four or more light emitting elements may be used. The sealing resin 27 may contain a dispersant or a phosphor.

A louver that blocks the incident of ambient light such as sunlight may be provided between the adjacent light emitting devices 2.

The shape of the light emitting surface 21 may be a convex shape in which the central portion of the light emitting surface 21 is highest in the Z-axis direction, in addition to the shape in which the light emitting surface 21 is parallel to the circuit board 4 as shown in FIG. Further, the central portion of the light emitting surface 21 may have a concave shape that is the lowest in the Z-axis direction.

The arrangement of the light emitting device 2 mounted on the mounting surface of the circuit board 4 is not limited to the square lattice, and may be another lattice such as an orthorhombic lattice, a hexagonal lattice, or a rectangular lattice. Further, it may be arranged in a houndstooth pattern. Alternatively, a blank space may be provided in a part where the light emitting device 2 is not arranged.

In the first embodiment, an example in which the protective portion 3 is made of a thin film is described, but it may be a resin molded product.

The protection unit 3 is in close contact with the mounting surface 11 of the circuit board 4, the light emitting surface 21 of the light emitting device 2, and the side surface 28a of the package 28, but it does not have to be in close contact with these surfaces. That is, partly between the protection unit 3 and the mounting surface of the circuit board 4, between the protection unit 3 and the light emitting surface 21 of the light emitting device 2, and between the protection unit 3 and the side surface 28a of the package 28. An air layer may be provided.

The shape of the fixed portion 51 is not limited to a conical shape, and may be a pyramid shape such as a triangular pyramid shape or a quadrangular pyramid shape, or a pillar shape such as a cylinder, a triangular prism, or a quadrangular prism.

The fixing portion 51 is not limited to the case where it is formed at the four corners of the upper surface 28c of the package 28 around the light emitting surface 21, but may be formed at two corners or three corners, and the fixed portion 51 of the package 28 around the light emitting surface 21. A plurality may be formed on the upper surface 28c.

The plurality of display device units 1 constituting the display device 41 are not necessarily limited to one type, and may be any combination of the above-mentioned plurality of types of display device units 1.

1 Display unit device, 2 Light emitting device, 3 Protective part, 4 Circuit board, 5 Wiring part, 6 Connection part, 11 Mounting surface, 21 Light emitting surface, 23r, 23g, 23b Light emitting element, 24 Wire, 25r, 25g, 25b Lead , 26r, 26g, 26b lead, 27 sealing resin, 28 package, 29 recesses, 31 recesses, 32 thin-walled parts, 41 display devices, 51 fixing parts.

Claims (7)

With the circuit board
A light emitting device mounted on the mounting surface of the circuit board and
A protective portion that covers the light emitting device and the mounting surface of the circuit board,
With
The light emitting device is arranged on a mounting surface of the circuit board, and seals a base member which is a housing having an open recess, a light emitting element mounted in the recess, and the light emitting element mounted in the recess. With a sealing member,
The protective portion includes a first covering portion that is formed of a flexible film that absorbs visible light and covers a light emitting surface that is a contact surface between the sealing member and an external space, and the first coating portion. It has a second coating portion that is integrally formed with the first coating portion and is thicker than the first coating portion around the coating portion.
The light emitting device is a display unit device that is arranged on the base member and has a fixing portion that fixes the first coating portion by abutting against the second coating portion around the first coating portion. The fixed portion is formed in a protruding shape, and the top thereof is formed higher than a virtual plane that passes through the top of the light emitting device and is parallel to the mounting surface of the circuit board with reference to the mounting surface of the circuit board. The display unit device according to claim 1. The display unit device according to claim 1 or 2, wherein the fixing portion is formed in a cone shape or a pillar shape. The display unit device according to claim 3, wherein the fixed portion has a conical shape, a triangular pyramid shape, a quadrangular pyramid shape, or a columnar shape, a triangular columnar shape, or a quadrangular columnar shape. Claim 1 is characterized in that the film constituting the protective portion has an adhesive layer and is arranged so as to be in close contact with the light emitting surface and side surface of the light emitting device and the mounting surface of the circuit board. The display unit device according to any one of 4 to 4. Wiring connected to the light emitting element is formed on the mounting surface of the circuit board.
The first coating portion of the film constituting the protection portion covers the light emitting surface of the light emitting device in a stretched state.
The second coating portion of the film constituting the protective portion covers at least the side surface of the light emitting device, the mounting surface of the circuit board, and the wiring, and one film constituting the protective portion covers the entire display unit device. Covers the plurality of the light emitting devices and the mounting surface of the circuit board.
The display unit device according to any one of claims 1 to 5, wherein the display unit device. A display device comprising a plurality of display unit devices according to any one of claims 1 to 6 in combination to form a display screen.

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