JP6092008B2 - LED display unit - Google Patents

Description

  The present invention relates to an LED display unit that displays information using an LED (light emitting diode).

  Conventionally, there has been known a display device in which bullet-type light-emitting diodes in which light-emitting diode chips are embedded in a bullet-type lens are arranged in a matrix (see Patent Document 1). In Patent Document 1, the light emitting direction of light in the light emitting diode chip is adjusted by biasing the light emitting diode chip from the central axis of the lens.

Japanese Utility Model Publication No. 5-79586

  However, in Patent Document 1, since the light emitting direction is determined at the stage where the light emitting diode chip is embedded in the lens, it is difficult to flexibly adjust the light emitting direction according to the direction in which the display device is visually recognized. There was a problem. That is, there is a problem that a bullet-type light emitting diode in which the position where the light emitting diode chip is embedded is changed in the lens must be prepared for each direction in which the display device is visually recognized. In addition, there is a problem that a large number of bullet-type light emitting diodes having directivity in the light emitting direction must be mounted so that the light emitting directions coincide with each other.

  The present invention is intended to solve the above-described problem, and an object of the present invention is to provide a technique that can easily adjust the direction of LED light emitted from a plurality of LEDs.

  In order to achieve the above object, an LED display unit of the present invention is arranged at a position corresponding to each of a plurality of LED light emitting units arranged on a substrate and a lens plate parallel to the substrate. And a positioning unit that relatively positions the substrate and the lens plate in a direction parallel to the substrate. Specifically, the positioning unit positions the substrate and the lens plate so that the relative positional relationship between the LED light emitting unit and the lens corresponding to each other is the same. Further, the positioning unit emits the LED light more than the reference straight line in which the emission direction in which the LED light emitted from each of the plurality of LED light emitting units is emitted to the outside of the lens passes through the optical axis of the LED light in the lens. The substrate and the lens plate are positioned so as to face the viewing position side of the part.

  By adjusting the relative positional relationship between the LED light emitting unit and the lens, it is possible to change the incident angle at which the LED light emitted from the LED light emitting unit is incident on the lens surface (incident surface / exit surface). Therefore, by adjusting the relative positional relationship between the LED light emitting unit and the lens, the emission direction in which the LED light is emitted from the lens can be adjusted. Here, the positioning unit positions the substrate and the lens plate so that the relative positional relationship between the pair of the LED light emitting unit and the lens corresponding to each other is the same. For example, if the light emitting axis of the LED light emitting unit and the apex of the lens are shifted by 1 mm in a certain group, the substrate and the lens are shifted so that the light emitting axis of the LED light emitting unit and the apex of the lens are shifted by 1 mm in all other sets. The plate is positioned. Therefore, in each set of the LED light emitting unit and the lens, the emission direction of the LED light is changed while maintaining the state in which the emission directions emitted from the lenses coincide, that is, the LED light emitted from each lens becomes parallel light. Can be adjusted at once. Note that the fact that the relative positional relationship is the same includes that there is a deviation in the relative positional relationship within the range of manufacturing error.

Further, the positioning unit is arranged so that the emission direction in which the LED light is emitted to the outside of the lens is directed to the viewing position side of the LED light emitting unit with respect to the reference straight line passing through the optical axis of the LED light in the lens. Position the lens plate. FIG. 1A is a diagram illustrating a state in which LED light is emitted to the outside of the lens. The incident angle of the LED light on the exit surface of the lens is expressed as α, and the refraction angle of the LED light on the exit surface is expressed as β. The incident angle α and the refraction angle β are angles based on the normal direction of the exit surface of the lens at the position where the LED light is emitted. Since the reference straight line is a straight line passing through the optical axis of the LED light in the lens, the incident angle α is an angle formed by the reference straight line and the normal direction of the exit surface of the lens. The following equation (1) based on Snell's law is established between the incident angle α and the refraction angle β.
n _L · sin α = n _O · sin β (1)

Here, n _L is the refractive index of the lens, and n _O is the refractive index of air. The refractive index n _{O of} air is approximately 1, and the refractive index n _{L of the} lens is usually greater than 1. Since sin α and sin β increase monotonously in the range of the incident angle α and the refraction angle β where total reflection does not occur, the refraction angle β is larger than the incident angle α when the above equation (1) is satisfied. Since the refraction angle β is larger than the incident angle α, the refraction angle β can be decomposed into a vertical angle component of the incident angle α and a directivity angle γ (> 0) as the remaining components with the reference straight line as a boundary. That is, the direction rotated by the incident angle α from the reference line becomes the normal direction of the emission surface, and the direction rotated by the directivity angle γ from the reference line to the opposite side of the normal direction becomes the LED light emission direction. Therefore, by positioning the substrate and the lens plate so that the normal direction of the lens emission surface at the position where the LED light is emitted to the outside of the lens is opposite to the visual recognition position across the reference straight line. The emitting direction of the LED light can be set to be closer to the visual recognition position side of the LED light emitting unit than the reference straight line.

  In the case of FIG. 1A, since the visual recognition position is below the reference straight line, the normal direction of the exit surface of the lens may be directed upward from the reference straight line. Thereby, it is possible to match the direction in which the visual recognition position exists with the direction in which the LED light is emitted from the lens with reference to the reference straight line. That is, LED light can be emitted toward the viewing position, and the visibility of the LED display unit at the viewing position can be improved.

  Further, each of the plurality of LED light emitting units emits the first LED that emits the first LED light and the second LED light having a wavelength longer than that of the first LED light in a range within 1 mm from the first LED in the direction parallel to the substrate. And a second LED. That is, the LED light emitting unit may be configured to emit a plurality of colors of LED light. The first LED light and the second LED light emitted from the single LED light emitting unit may pass through the single lens in parallel with each other. Thus, by passing the first LED light and the second LED light through a single lens, it is not necessary to provide a lens corresponding to each of the first LED light and the second LED light, and the cost can be suppressed. Furthermore, it is not necessary to adjust the position of the lens for each of the first LED light and the second LED light. As described above, when the LED light emitting unit includes a plurality of LEDs, the emission direction in which the LED light emitted from all the LEDs is emitted to the outside of the lens is directed to the visual recognition position side of the LED light emitting unit with respect to the reference straight line. In this way, the substrate and the lens plate may be positioned. However, if the first LED and the second LED are provided at different positions, the normal directions of the emission surfaces from which the first LED light and the second LED light are emitted from the lens are different from each other, and the emission directions are different from each other. When the difference in the emission direction in which the first LED light and the second LED light are emitted from the lens is large, the color mixing property between the first LED light and the second LED light is lowered.

  On the other hand, by providing the first LED and the second LED within a range of 1 mm or less, the optical axis of the first LED and the optical axis of the second LED in the lens can be brought close to each other, and the first LED light and the second LED It is possible to suppress a difference in the normal direction of the exit surface from which light is emitted from the lens. That is, it is possible to suppress a difference in the emission direction in which the first LED light and the second LED light are emitted from the lens, and it is possible to suppress a decrease in color mixing between the first LED light and the second LED light. In addition, when the LED light emitting unit is an SMD (Surface Mount Device) in which the first LED and the second LED are mounted in a single package, the first LED and the second LED can be easily arranged within a range of 1 mm or less. Further, the substrate and the lens plate are arranged so that the first LED light and the second LED light are emitted in a region where the change amount of the inclination of the emission surface in the optical axis direction is smaller than a predetermined reference among the emission surfaces of the lens. You may position. Thereby, the difference of the normal line direction of the injection | emission surface in which 1st LED light and 2nd LED light are inject | emitted from a lens can be suppressed.

  Further, the positioning unit is configured such that the surface of the lens at the position where the second LED light is emitted to the outside of the lens is larger than the incident angle of the first LED light to the surface of the lens at the position where the first LED light is emitted to the outside of the lens. You may position a board | substrate and a lens board so that the incident angle of 2nd LED light with respect to may become large. Thereby, it can suppress that the color mixing property of 1st LED light and 2nd LED light falls. The reason will be described below.

Since β = α + γ as described above, the above equation (1) can be expressed as the following equation (2).
n _L · sin α = n _O · sin (α + γ) (2)
As described above, since sin α and sin β increase monotonously in the range of the incident angle α and the refraction angle β where total reflection does not occur, the above equation (2) indicates that the directivity angle γ increases as the incident angle α increases. Means to grow. Further, the above equation (2) means that the directivity angle γ increases as the refractive index n _{L of the} lens increases.

Here, the refractive index of visible light in an object has a property (normal dispersion) that decreases as the wavelength of the visible light increases. Therefore, the first refractive index n _L1 that is the refractive index of the first LED light (short wavelength) in the lens is larger than the second refractive index n _L2 that is the refractive index of the second LED light (long wavelength) in the lens. . Therefore, when the incident angles α are the same, the directivity angle γ of the first LED light is larger than the directivity angle γ of the second LED light.

Next, as shown in FIGS. 1B and 1C, the first LED light is emitted from one of the two points Q and W having different incident angles α on the exit surface of the lens, and the second LED light is emitted from the two points Q and W. Consider the case of being emitted from the other of W. When the emission surface of the lens is a curved surface and the first LED and the second LED are provided at positions shifted from each other, the first LED light and the second LED light are emitted from points Q and W having different incident angles α. Become. The incident angles α when incident on the two points Q and W are α _W and α _Q (α _W > α _Q ), respectively. For example, when a package on which the first LED and the second LED are mounted can be inverted by 180 ° with respect to the substrate, the incident angle α is different from either of two points Q and W as shown in FIGS. 1B and 1C. Whether to emit the first LED light and the second LED light can be selected.

Here, as shown in FIG. 1B, when the first LED light having a short wavelength is emitted from the point Q having the incident angle α _Q , the directivity angle γ _Q1 is incident on the second LED light having a long wavelength as shown in FIG. 1C. It becomes larger than the directivity angle γ _Q2 when emitted from the point _{Q that} is the angle α _Q. This is because when the incident angle α _Q is the same, the directivity angle γ increases as the refractive index n _{L of the} lens increases. Similarly, as shown in FIG. 1C, when the first LED light having a short wavelength is emitted from the point W where the incident angle α _W is incident, the directivity angle γ _W1 is incident on the second LED light having a long wavelength as shown in FIG. 1B. It becomes larger than the directivity angle γ _W2 when emitted from the point _W that becomes the angle α _W. Thus, the following equations (3) and (4) are established.
γ _Q1 > γ _Q2 (3)
γ _W1 > γ _W2 (4)

Here, the directivity angle γ _W1 when the first LED light is emitted from the point _W at a large incident angle α _W as shown in FIG. 1C is the point at the small incident angle α _Q when the first LED light is small as shown in FIG. 1B. It becomes larger than the directivity angle γ _Q1 when emitted from Q. This is because the directivity angle γ increases as the incident angle α increases. Similarly, the directivity angle γ _W2 when the second LED light is emitted from the point _W with a large incident angle α _W as shown in FIG. 1B is the point at the small incident angle α _Q when the second LED light is small as shown in FIG. 1C. It becomes larger than the directivity angle γ _Q2 when emitted from Q.
Thus, the following expressions (5) and (6) are established.
γ _W1 > γ _Q1 (5)
γ _W2 > γ _Q2 (6)

The following expression (7) can be derived from the above expressions (4) and (6).
γ _W1 > γ _W2 > γ _Q2 (7)
Furthermore, the following equation (8) can be derived from the above equations (3) and (5).
γ _W1 > γ _Q1 > γ _Q2 (8)

As shown in (7) and (8) above, the first LED light having a short wavelength out of the directivity angles γ _Q1 , γ _Q2 , γ _W1 and γ _W2 is emitted from the point W at a large incident angle α _W. The directivity angle γ _W1 is maximized, and the directivity angle γ _Q2 when the second LED light having a long wavelength is emitted from the point Q at a small incident angle α _Q is minimized. Accordingly, when the substrate and the lens plate are positioned so that the first LED light having a short wavelength is incident on the point _W at a large incident angle α _W and the second LED light having a long wavelength is incident on the point Q at a small incident angle α _Q. The difference between the directivity angles γ _W1 and γ _Q2 of the first LED light and the second LED light emitted from the lens becomes the maximum, and the color mixing property between the first LED light and the second LED light is lowered. In contrast, the substrate and the lens plate are arranged so that the first LED light having a short wavelength enters the point _Q at a small incident angle α _Q and the second LED light having a long wavelength enters the point W at a large incident angle α _W. When the positioning is performed, the difference between the directivity angles γ _Q1 and γ _W2 between the first LED light and the second LED light emitted from the lens does not become maximum, so that the color mixing property between the first LED light and the second LED light can be ensured.

  The positioning unit may position the substrate and the lens plate at a plurality of relative positions in a direction parallel to the substrate. Thereby, the relative position of a board | substrate and a lens board can be changed according to a visual recognition position, and a flexible installation position can be given to the information display apparatus provided with an LED display unit. For example, the relative position of the LED substrate and the lens plate can be changed according to the gradient of the ground where the viewer of the information display device exists, the height of the viewing position from the ground, or the like.

(1A)-(1C) are the schematic diagrams explaining the optical path of LED light. (2A) is a front view of the information display device, and (2B) is a side view of the information display device. (3A) is a front view of the substrate, and (3B) is a front view of the lens plate. (4A) is a side view of the lens, (4B) to (4D) are side views of the positioning holes, and (4E) is a side view of the fixing holes. (5A) and (5B) are side views of the lens. It is a graph which shows the relationship between an incident angle and a directivity angle. (7A) is a schematic diagram of the visual recognition position and shift distance according to another embodiment, and (7B) is a graph showing the relationship between the shift distance and the directivity angle of the LED light.

Here, embodiments of the present invention will be described in the following order.
(1) Configuration of information display device:
(2) Configuration of substrate and lens plate:
(3) About shift distance and LED arrangement:
(4) Other embodiments:

(1) Configuration of information display device:
2A and 2B are a front view and a side view showing a schematic configuration of an information display device including the LED display unit according to the present embodiment. The information display device 1 includes a display unit D, a support column 13, a protective housing 14, and a control unit 15. The display unit D and the control unit 15 are accommodated in the protective housing 14. The protective housing 14 is supported at a predetermined height H from the road surface by a column 13 erected on the shoulder of the road. Note that the protective housing 14 does not necessarily have to be supported by the support column 13 and may be attached to, for example, a wall surface or a building.

  The front surface of the display unit D is formed in a planar shape, and is configured by a plurality (for example, 12 × 12) of LED display units 10. The site | part which opposes the front of the display part D among the protective housings 14 is transparent. Thereby, the various road information displayed on the display part D can be visually recognized from the vehicle which drive | works on a road. The LED display unit 10 constitutes a vertical plane. The plurality of LED display units 10 are arranged on the same plane in the vertical direction so as to constitute a vertical plane of the display unit D. The height H is assumed to be the height from the road surface at the midpoint in the height direction of the display unit D. As shown in FIG. 2B, the information display device 1 is configured so that the road is horizontal and the display D can be easily seen from the visual recognition position P on the road surface that is V apart from the display D in the horizontal direction. And The height h of the visual recognition position P from the road surface is, for example, the average eye height of a driver of a vehicle traveling on the road surface or a pedestrian walking on the road surface. When the elevation angle when the display unit D is easy to see is expressed as a directivity angle γ, the directivity angle γ is an angle satisfying tan γ = (H−h) / V.

  The control unit 15 is provided on the back side of the display unit D, for example. The control unit 15 includes a power supply unit connected to an external commercial power supply, and the power supply unit generates power to be supplied to various circuits of the control unit 15 and the display unit D. The control unit 15 includes a receiving unit that communicates with an external server or the like via a communication line such as a wireless, Internet line, or dedicated line and receives display data indicating various information such as road information displayed on the display unit D. . Further, the control unit 15 includes a circuit for controlling lighting of each LED display unit 10 by performing various signal processing based on the display data.

(2) Configuration of substrate and lens plate:
FIG. 3A is a front view of the substrate 11.
The substrate 11 is a flat plate on which a circuit is printed, and a plurality (16 × 16) of LED light emitting units M are arranged in a matrix on the substrate 11. As shown in FIG. 2B, the substrate 11 is provided in the information display device 1 so as to be a plane in the vertical direction. The LED light emitting units M are linearly arranged at a constant interval J (10.0 mm) in the vertical direction on the substrate 11 and are also linearly arranged at a constant interval J in the horizontal direction.

  FIG. 3B is a front view of the lens plate 12. The lens plate 12 is a flat plate, and a plurality of lenses L are arranged in a matrix on the lens plate 12. As shown in FIG. 2B, the lens plate 12 is provided in the information display device 1 so as to be a plane in the vertical direction. Accordingly, the substrate 11 and the lens plate 12 are parallel to each other. On the lens plate 12, the lenses L are linearly arranged at regular intervals J in the vertical direction, and are also arranged linearly at regular intervals J in the horizontal direction. Further, the number of LED light emitting units M and the number of lenses L are the same. That is, the plurality of lenses L are arranged on the lens plate 12 parallel to the substrate 11 at positions corresponding to the plurality of LED light emitting units M, respectively.

  4A is a side view for explaining the relative positional relationship between the LED light emitting unit M and the lens L. FIG. In the present embodiment, the LED light emitting unit M is an SMD (Surface Mount Device) in which a red LEDr, a green LEDg, and a blue LEDb are mounted on a single package. In the LED light emitting unit M, the red LEDr, the green LEDg, and the blue LEDb are arranged in order from the top on a straight line in the vertical direction with a constant element interval I (0.5 mm). The center position of the green LEDg in the vertical direction is referred to as a reference position F of the LED light emitting unit M. The red LEDr emits red LED light R having a wavelength of 0.63 nm, the green LEDg emits green LED light G having a wavelength of 0.53 nm, and the blue LEDb emits blue LED light B having a wavelength of 0.47 nm. . The red LEDr, the green LEDg, and the blue LEDb are mounted so that the optical axis of the red LED light R, the optical axis of the green LED light G, and the optical axis of the blue LED light B are perpendicular to the substrate 11, respectively. Yes. Therefore, the optical axis of the red LED light R, the optical axis of the green LED light G, and the optical axis of the blue LED light B are respectively horizontal optical axes.

The lens L is a plano-convex lens having a planar incident surface L ₁ parallel to the substrate 11 on the substrate 11 side and a convex exit surface L ₂ on the opposite side of the substrate 11. In the present embodiment, the exit surface L ₂ of the lens L has a hemispherical shape with a curvature radius C of 3.8 mm. The exit surface L ₂ of the lens L has a vertex T at which the height (distance) from the lens plate 12 is the largest. In the present embodiment, the lens L is made of transparent polycarbonate. The position of the vertex T in the vertical direction is denoted as the reference position K of the lens L. The distance in the vertical direction between the reference position F of the LED light emitting unit M and the reference position K of the lens L is referred to as a shift distance Z. The shift distance Z is obtained by subtracting the reference position K of the lens L from the reference position F of the LED light emitting unit M in the vertical direction, and the reference position K of the lens L is higher than the reference position F of the LED light emitting unit M. When it exists below, it becomes a positive value. 4A shows a vertical cross section passing through the apex T and orthogonal to the substrate 11. FIG. Although not shown, in the horizontal direction, the position of the vertex T of the lens L coincides with the positions of the red LEDr, the green LEDg, and the blue LEDb.

(3) About shift distance:
Hereinafter, a method for setting the shift distance Z will be described. The shift distance Z is set so that the green LED g emitted from the green LED g is emitted in a direction inclined from the horizontal direction to the viewing position P by the directivity angle γ from the horizontal direction. . That is, the shift distance Z is set so that the green LED light G can be easily viewed when viewed at the viewing position P at the elevation angle of the directivity angle γ. Since the green LEDg is disposed at a position intermediate between the red LEDr and the blue LEDb in the vertical direction, the optical axis of the green LED light G is the average optical axis of the red LED light R and the blue LED light B. means.

The red LED light R, green LED light G, and blue LED light B emitted in the horizontal direction are perpendicularly incident on the incident surface L ₁ of the lens L. The red LED light R, green LED light G, and blue LED light B incident perpendicularly to the incident surface L ₁ of the lens L travel straight through the lens L as they are. That is, the red LED light R, the green LED light G, and the blue LED light B emitted from the single LED light emitting unit M pass through the single lens L in parallel with each other. A straight line passing through the optical axis of the green LED light G in the lens L is referred to as a reference straight line S. In the present embodiment, the reference straight line S is a horizontal straight line.

The visual recognition position P exists below the reference straight line S. Accordingly, the normal direction of the exit surface L ₂ of the lens L at the position where the green LED light G is emitted is more than the reference line S so that the green LED light G is emitted closer to the visual recognition position P than the reference line S. It suffices to face upward. That is, the green LED light G may be so as to pass a position above the apex T of the injection surface L _2. In other words, the reference position K of the lens L may be set lower than the reference position F of the LED light emitting unit M, and the shift distance Z may be set to a positive value.

As described above, the expression (2) is established between the incident angle α and the directivity angle γ. In the above equation (2), the refractive index n _L (1.5881) of the green LED light G in the lens L, the refractive index n _O of the green LED light G in the air (1 regardless of wavelength), and the directivity. The incident angle α can be calculated by substituting the angle γ. When the directivity angle γ is 20 °, when the equation (2) is solved with respect to the incident angle α, the incident angle α is 27.81 °. The refractive index of visible light in the lens L has a property (normal dispersion) that decreases as the wavelength of the visible light increases. By preparing a graph indicating the refractive index for each wavelength (for example, JP 2010-250925 A, FIG. 4) for the material of the lens L (polycarbonate), and reading the refractive index corresponding to the wavelength of the green LED light G, it is possible to obtain a refractive index n _L of the green LED light G in the lens L.

Further, the relationship between the incident angle α and the shift distance Z can be specified based on the shape of the exit surface L ₂ . In the present embodiment, since the emission surface L ₂ is a hemispherical surface, the shift distance Z for setting the incident angle α of the green LED light G to 27.81 ° can be calculated by the following equation (9).
Z = C · sinα (9)
In this embodiment, the radius of curvature C of the injection surface L ₂ is 3.8 mm, and the shift distance Z is 1.75 mm.

  In the above equations (2) and (9), when 15 ° is substituted as the directivity angle γ, the incident angle α can be calculated as 22.58 °, and the shift distance Z can be calculated as 1.46 mm. Similarly, if the directivity angle γ is 10 °, the incident angle α can be calculated as 16.06 °, and the shift distance Z can be calculated as 1.05 mm.

  In the present embodiment, a plurality of positioning holes U are formed in the substrate 11 and the lens plate 12 so that the substrate 11 and the lens plate 12 can be positioned at a plurality of relative positions in a direction parallel to the substrate 11. ing. The plurality of relative positions mean relative positions of the substrate 11 and the lens plate 12 at which the shift distance Z is 1.05 mm, 1.46 mm, and 1.75 mm, and the directivity angle γ is 10 °, 15 °, and 20 °. This means the relative position between the substrate 11 and the lens plate 12.

As shown in FIGS. 3A and 3B, the positioning holes U ₁₀ , U ₁₅ , and U ₂₀ are on a bisector that bisects the substrate 11 and the lens plate 12 in the horizontal direction in each of the substrate 11 and the lens plate 12. Six (one-dot chain line) are provided. Further, one positioning hole U ₁₀ , U ₁₅ , U ₂₀ is provided above and below the bisector that bisects the substrate 11 in the vertical direction, and the lens plate 12 is bisected in the vertical direction. One is provided above and below the bisector. 4B, 4C, and 4D are views showing how positioning is performed in the positioning holes U ₁₀ , U ₁₅ , and U ₂₀ .

As shown in FIG. 4B, in a state where the positioning hole U ₁₀ of the positioning hole U ₁₀ and the lens plate 12 is overlapped the substrate 11, by screwing so as to penetrate the positioning holes U _10, directivity angle γ is The substrate 11 and the lens plate 12 can be positioned with a shift distance Z (1.05 mm) of 10 °. Incidentally, in a state in which overlapping positioning hole U ₁₀ between which is provided above the substrate 11 and the lens plate 12. Even overlaps the positioning hole U ₁₀ together provided below. Therefore, the substrate 11 and the lens plate 12 can be fixed at two points having different positions in the vertical direction, and the lens plate 12 can be prevented from rotating with respect to the substrate 11 in a plane parallel to the substrate 11.

As shown in FIG. 4C, in a state where the positioning hole U ₁₅ of the positioning hole U ₁₅ and the lens plate 12 is overlapped the substrate 11, by screwing so as to penetrate the positioning holes U _15, directivity angle γ is The substrate 11 and the lens plate 12 can be positioned with a shift distance Z (1.46 mm) of 15 °. Furthermore, as shown in FIG. 4D, in a state where the positioning hole U ₂₀ are overlapped positioning hole U ₂₀ and lens plate 12 of the substrate 11, by screwing so as to penetrate the positioning holes U _20, directivity angle The substrate 11 and the lens plate 12 can be positioned at a shift distance Z (1.75 mm) where γ is 20 °. The hole diameters of the positioning holes U ₁₀ , U ₁₅ , U ₂₀ are all equal to the diameter of the shaft portion of the screw.

The positions of the positioning holes U ₁₀ , U ₁₅ , U ₂₀ provided on the bisector that bisects the substrate 11 in the horizontal direction are provided on the bisector that bisects the lens plate 12 in the horizontal direction. It coincides with the position of the positioning holes U ₁₀ , U ₁₅ , U ₂₀ . Therefore, the relative positions of the substrate 11 and the lens plate 12 are positioned while keeping the position of the bisector that bisects in the horizontal direction coincident. That is, the substrate 11 and the lens plate 12 move relative to each other only in the vertical direction without moving in the horizontal direction by changing the positioning holes U ₁₀ , U ₁₅ , and U ₂₀ for screwing. .

As shown in FIGS. 3A and 3B, seven fixing holes X are provided in each of the substrate 11 and the lens plate 12. In each of the substrate 11 and the lens plate 12, the fixing holes X are formed at the center of gravity, near the four corners, and near the midpoint of the left and right sides. FIG. 4E is a diagram illustrating a state in which screwing is performed in the fixing hole X. Positioning holes U ₁₀ and the lens plate 12 a state where the positioning hole U ₁₀ overlap the substrate 11, a state where the positioning hole U ₁₅ of the positioning hole U ₁₅ and lens plate 12 of the substrate 11 are overlapped, and the positioning of the substrate 11 in either the positioning hole U ₂₀ holes U ₂₀ and the lens plate 12 is overlapped state also, as the fixing hole X of the fixing hole X and the lens plate 12 of the substrate 11 is overlapped, fixing hole X of the lens plate 12 is It is a long hole in the vertical direction. The length of the fixing hole X of the lens plate 12 in the vertical direction is the length (0.70 mm) obtained by subtracting the minimum shift distance Z (1.05 mm) from the maximum shift distance Z (1.75 mm). It is more than the length added. The horizontal length of the fixing hole X of the lens plate 12 is shorter than the diameter of the screw head. On the other hand, the hole diameter of the fixing hole X of the substrate 11 is all equal to the diameter of the screw. Further, at a position within a predetermined distance from the fixing hole X, a spacer A for keeping the distance between the substrate 11 and the lens plate 12 constant is provided at a constant height.

As described above, by providing the positioning holes U ₁₀ , U ₁₅ , U ₂₀ and the fixing hole X, the substrate 11 and the lens plate 12 can be relatively moved in the vertical direction while maintaining a parallel state. . Since the relative positional relationship between the LED light emitting portions M on the substrate 11 is unchanged, and the relative positional relationship between the lenses L on the lens plate 12 is unchanged, the shift distance of the lens L with respect to a single LED light emitting portion M is unchanged. Setting Z to 1.75 mm, for example, means that the shift distance Z of the lens L with respect to all the LED light emitting units M is set to 1.75 mm. That is, the substrate 11 and the lens plate 12 can be positioned so that the relative positional relationship (shift distance Z) in each pair of the LED light emitting unit M and the lens L corresponding to each other is the same. The positioning holes U ₁₀ , U ₁₅ , U ₂₀ , the fixing hole X, the screw, and the spacer A correspond to the positioning portion of the present invention. Further, the substrate 11 and the lens plate 12 are positioned so as to have the same shift distance Z in all the LED display units 10.

  In the above, when the green LED g emits the green LED light G, the green LED light G is emitted in a direction inclined by the directivity angle γ (10 °, 15 °, 20 °) toward the viewing position P from the horizontal direction. I explained what I can do. Hereinafter, the direction in which the red LED light R and the blue LED light B are emitted will be considered as an example where the directivity angle γ is 20 °.

FIG. 5A is a diagram showing optical axes of red LED light R and blue LED light B. FIG. When the directivity angle γ is 20 °, the shift distance Z, which is the vertical distance of the apex T of the lens L with respect to the green LEDg, is 1.75 mm, so the distance of the apex T of the lens L with respect to the blue LEDb is 1.25 mm. (Z−I), and the distance of the apex T of the lens L to the red LEDr is 2.25 mm (Z + I). Since the directions of the optical axes in the lens L of the red LED light R, the green LED light G, and the blue LED light B are all horizontal, 2.25 mm and 1.25 mm are set to the shift distance Z in the equation (9). By substituting, the incident angle α _W (36.5 °) of the red LED light R with respect to the exit surface L ₂ of the lens L and the incident angle α _Q (20.2 °) of the blue LED light B can be calculated. The point at which the red LED light R is emitted at the exit surface L ₂ represented is W, it denoted the point where the blue LED light B is emitted by an injection surface L ₂ and Q. The refractive index n _LR of the red LED light R in the polycarbonate lens L is 1.5780, and the refractive index n _LB of the blue LED light B is 1.5972.

The critical angle α _C of the incident angle α with respect to the exit surface L ₂ of the lens L can be calculated by the following equation (10).
α _C = arcsin (n _O / n _L ) (10)
By substituting the refractive index n _LR of the red LED light R and the refractive index n _LB of the blue LED light B in the lens L into the equation (10), the critical angle α _C (39.3 °) of the red LED light R is obtained. ) And the critical angle α _C (38.8 °) of the blue LED light B is obtained. The incident angle α _W (36.5 °) of the red LED light R and the incident angle α _W (20.2 °) of the blue LED light B are both critical angles α _C (39.3 °, 38.8 °). ), The red LED light R and the blue LED light B can be emitted from the lens L without being totally reflected.

By substituting the incident angle α _W of the red LED light R into the equation (2), the directivity angle γ _WR (33.3 °) of the red LED light R emitted at the point W can be calculated. Similarly, the directivity angle γ _QB (13.3 °) of the blue LED light B emitted at the point Q can be calculated by substituting the incident angle α _Q of the blue LED light B into the equation (2). . Therefore, the difference dγ the directional angle gamma _WR directivity angle gamma _QB of the blue LED light B of the red LED light R becomes 20 °.

Here, as shown in FIG. 5B, consider a case where the red LEDr and the blue LEDb are arranged 180 ° inverted from the state of FIG. 5A around the green LEDg. In this case, the incident angle α W of the blue LED light B at the point _W is 36.5 °, and the incident angle α _Q of the red LED light R at the point _Q is 20.2 °. By substituting these into the above equation (2), the directivity angle γ _WB (35.3 °) of the blue LED light B emitted at the point W can be calculated. Similarly, the directivity angle γ _QR (12.8 °) of the red LED light R emitted at the point Q can be calculated by substituting the incident angle α _Q of the red LED light R into the equation (2). . Therefore, the difference dγ between the directivity angle γ _QR of the red LED light R and the directivity angle γ _WB of the blue LED light B is 22.5 °.

FIG. 6 shows an incident that satisfies the above-described equation (2) when the refractive index n _LR of the red LED light R, the refractive index n _L of the green LED light G, and the refractive index n _LB of the blue LED light B are applied. It is a graph which shows the relationship between angle (alpha) and directivity angle (gamma). In the figure, the horizontal axis indicates the incident angle α, and the vertical axis indicates the directivity angle γ. Further, it is assumed that the directivity angle γ of the green LED light G is set to 20 ° (the incident angle α of the green LED light G is 27.81 °). As shown in FIG. 6, in any of the red LED light R, the green LED light G, and the blue LED light B, the directivity angle γ increases monotonously as the incident angle α increases. In addition, the directivity angle γ increases in the order of shorter wavelengths. Therefore, as shown in FIG. 5B, the directivity angle γ _WB when the blue LED light B having the shortest wavelength is emitted from the point W at which the incident angle α is 36.5 ° is maximized. Further, as shown in FIG. 5B, the directivity angle γ _QR when the red LED light R having the longest wavelength is emitted from the point Q where the incident angle α is 20.2 ° is minimized. That is, when the LED light emitting unit M is installed as shown in FIG. 5B, the directivity angle γ _WB of the blue LED light B and the directivity angle γ _QB of the red LED light R are the maximum and minimum combinations, and the directivity angle γ _WB The difference dγ between the directivity angle γ _QR and the directivity angle γ _QR is maximized. On the other hand, as shown in FIG. 5A, the incident angle α _{W of the} red LED light R having a longer wavelength with respect to the emission surface L _{2 is} larger than the incident angle α _{Q of the} blue LED light B having a shorter wavelength with respect to the emission surface L ₂ . By relatively positioning the substrate 11 and the lens plate 12 so as to increase, the difference dγ in the directivity angle γ can be suppressed. By suppressing the difference dγ in the directivity angle γ, the color mixing property of the red LED light R, the green LED light G, and the blue LED light B at the viewing position P can be improved.

Furthermore, according to the above equation (10), the critical angle α _C decreases as the LED light has a higher refractive index n, that is, as the LED light has a shorter wavelength. Accordingly, as shown in FIG. 5A, by arranging the blue LEDg at the lowest position (position close to the vertex T) so that the incident angle α of the blue LED light B having the smallest critical angle α _C becomes the smallest. The blue LED light B can be prevented from being totally reflected. That is, the shift distance Z can be increased and the directivity angle γ can be increased while preventing the total reflection of the LED lights R, G, and B of the respective colors.

In the configuration of the present embodiment described above, by adjusting the shift distance Z, the LED lights R, G, and B emitted from all the LED light emitting units M provided on the substrate 11 are directed toward the viewing position P. Can be adjusted at once. That is, the position of the lens L may not be adjusted for each LED light emitting unit M, and the position of the lens L may not be adjusted for each of the red LEDr, green LEDg, and blue LEDb included in the LED light emitting unit M. Strictly speaking, the red LED light R, the green LED light G, and the blue LED light B are emitted from the lens L at different directivity angles γ _QB , γ, and γ _WR but have the longest wavelength. By making the incident angle α _W with respect to the exit surface L ₂ of the lens L of the lens L larger than the incident angle α _{Q with} respect to the exit surface L ₂ of the lens L of the blue LED light B having the shortest wavelength, the directivity angles γ _QB , γ, The difference of γ _WR can be suppressed.

(4) Other embodiments:
FIG. 7A is a schematic diagram showing the relationship between the visual recognition position P and the shift distance Z in another embodiment. The figure is a view of the display unit D installed in the vertical direction as seen from the front side. If the viewing position P ₁ is present at a position below the display unit D just a predetermined distance from the display unit D, the shift distance Z ₁ is set so that the lens L is displaced downward relative to the LED light emitting unit M. Good. Further, when the visual recognition position P ₂ exists at a position above the display unit D, the shift distance Z ₂ may be set so that the lens L is displaced upward with respect to the LED light emitting unit M. Furthermore, when the visual recognition position P ₃ is present at the right position of the display unit D, the shift distance Z ₃ may be set so that the lens L is shifted to the right side with respect to the LED light emitting unit M. On the other hand, when the visual recognition position P ₄ exists at the left position of the display unit D, the shift distance Z ₄ may be set so that the lens L is shifted to the left side with respect to the LED light emitting unit M. In addition to the viewing position P shown in the figure, for example, when the viewing position P exists diagonally to the lower left of the display unit D, the shift distance Z is set so that the lens L is shifted obliquely to the lower left with respect to the LED light emitting unit M. Good.

  As described above, the LED display unit 10 can be configured to be easily visible from the viewing position P by shifting the lens plate 12 in the direction of the viewing position P in the direction parallel to the substrate 11. Note that the substrate 11 and the lens plate 12 do not necessarily need to be positioned at a plurality of relative positions, and can be positioned at a single relative position assuming only a single viewing position P. Also good. For example, the substrate 11 and the lens plate 12 may be positioned at a single relative position by bonding them with an adhesive. Furthermore, when the substrate 11 and the lens plate 12 are positioned at a plurality of relative positions, they need not be positioned by screwing. For example, positioning may be performed by a locking claw or a pin, or positioning may be performed by hanging the lens plate 12 from the substrate 11 with a hook. Further, the substrate 11 and the lens plate 12 may be connected via a slide rail so that the relative movement between the substrate 11 and the lens plate 12 is facilitated. In addition, the display part D may be comprised with the single LED display unit 10, and the lens board 12 may be provided so that the some board | substrate 11 may be straddled. Furthermore, the lens plate 12 may be, for example, an integrally molded member, or may be formed by combining a plurality of members including the lens L so that they cannot move relative to each other.

  The LED light emitting unit M only needs to be mounted with one LED so that at least one color of LED light can be emitted. Furthermore, in the said embodiment, although the shift distance Z was set based on the optical path of the green LED light G formed in an average position, the shift distance Z was set based on the optical path of the red LED light R and the blue LED light B. It may be set. For example, the shift distance Z may be set so that the average value of the directivity angle γ of the red LED light R and the directivity angle γ of the blue LED light B becomes the target directivity angle γ.

FIG. 7B is a graph showing the relationship between the shift distance Z and the directivity angle γ of each color LED light R, G, B. In the figure, the horizontal axis indicates the shift distance Z representing the position of the green LED g, and the vertical axis indicates the directivity angle γ of each color LED light R, G, B. Since the red LED light R is emitted from a point W that is 0.5 mm above the green LED light G, the incident angle α _W is larger than that of the green LED light G. Therefore, the directivity angle γ _WR of the red LED light R is always larger than the directivity angle γ of the green LED light G. On the other hand, since the blue LED light B is emitted from a point W lower by 0.5 mm than the green LED light G, the incident angle α _Q is smaller than that of the green LED light G. Therefore, the directivity angle γ _QB of the blue LED light B is always smaller than the directivity angle γ of the green LED light G. Further, as the distance from the apex T of the lens L in the vertical direction increases, the amount of increase in the incident angle α per unit distance increases, and the amount of increase in the directivity angle γ per unit distance increases. Therefore, the larger the shift distance Z is, the difference between the directivity angle gamma _WR directivity angle gamma _QB of the blue LED light B of the red LED light R d [gamma] is increased.

Since the difference dγ in the directivity angle γ increases as the difference in the incident angle α between the LED lights R and B increases, it is desirable to set the shift distance Z small. That is, the shift distance Z is set so that the LED lights R and B are emitted from a region where the inclination in the optical axis direction on the emission surface L ₂ is small so that the difference in the incident angle α between the LED lights R and B is small. It is desirable to suppress it. For example, the LED display unit 10 itself is inclined from the vertical direction so that the visual recognition position P is close to the reference straight line S, thereby reducing the directivity angle γ (shift distance Z) and the directivity angle γ between the LED lights R and B. The difference dγ between _QB and γ _WR may be suppressed. For example, if the directivity angle γ of the green LED light G is suppressed to 10 ° by tilting the LED display unit 10 itself, the difference dγ between the directivity angles γ _QB and γ _WR between the LED lights R and B is 10.5. Can be suppressed up to °. Further, by increasing the refractive index n _L of lenses L, may suppress the shift distance Z to achieve the desired directional angle gamma. For example, the material of the lens L may be a synthetic resin such as silicon resin other than polycarbonate, or glass, and the shift distance Z may be set according to the refractive index n of these materials. Further, the difference in the incident angle α may be suppressed by increasing the radius of curvature C of the exit surface L ₂ of the lens L. Of course, the difference in the incident angle α between the LED lights R and B may be suppressed by reducing the element interval I between the red LEDr, the green LEDg, and the blue LEDb.

Further, the lens L may not be a spherical lens but may be an aspheric lens. For example, the shape of the emission surface L ₂ may be set so that the inclination in the optical axis direction in the region where the LED lights R, G, and B are emitted becomes small. Further, the normal direction of the emission surface L ₂ at the position where the LED lights R, G, and B are emitted may be on the opposite side of the visual recognition position P from the reference straight line S, and the lens L may be a concave lens. Good.

  DESCRIPTION OF SYMBOLS 1 ... Information display apparatus, 10 ... Display unit, 11 ... Board | substrate, 12 ... Lens board, 13 ... Support | pillar, 14 ... Protective housing, 15 ... Control unit, D ... Display part, L ... Lens, M ... LED light emission part, P: visual recognition position, S: reference straight line, U: positioning hole, X: fixing hole, W: point, Z: shift distance, α: incident angle, γ: directivity angle.

Claims (4)

A plurality of LED light emitting units disposed on the substrate;
A plurality of lenses arranged at positions corresponding to each of the plurality of LED light emitting units on a lens plate parallel to the substrate;
A positioning unit that relatively positions the substrate and the lens plate at a plurality of relative positions in a direction parallel to the substrate, and an LED display unit comprising:
The positioning part is
Positioning the substrate and the lens plate so that the relative positional relationship in each of the pair of the LED light emitting unit and the lens corresponding to each other is the same,
The LED light emitting unit is configured such that an emission direction in which LED light emitted from each of the plurality of LED light emitting units is emitted to the outside of the lens is more than a reference straight line passing through the optical axis of the LED light in the lens. Positioning the substrate and the lens plate so as to face the viewing position side of
An LED display unit characterized by that.


Each of the plurality of LED light emitting units includes a first LED that emits first LED light, and a second LED that emits second LED light having a wavelength longer than that of the first LED light within a range of 1 mm from the first LED. Have
The first LED light and the second LED light emitted from a single LED light-emitting unit pass through the single lens in parallel with each other,
The LED display unit according to claim 1. The positioning part is
The first LED light is emitted to the outside of the lens, and the second LED light is emitted to the outside of the lens with respect to the exit surface of the lens. 2 relatively positioning the substrate and the lens plate so as to increase the incident angle of the LED light;
The LED display unit according to claim 2. The positioning part is
Positioning the substrate and the lens plate at a plurality of relative positions in a direction parallel to the substrate;
The LED display unit as described in any one of Claims 1-3.

Images