Indication device

Abstract

It reduces installation costs while displaying a natural flow of light. [Solution] The LED module 2 has N LEDs 22 arranged in the X direction on an LED substrate 21. The incident part 31 of the light guide plate 3 is positioned opposite the LEDs 22 in the Y direction, and the light L emitted by the LEDs 22 is incident on it. The output part 32 emits the light L that has been incident on the incident part 31. The control device 5 lights up the N LEDs 22 in the X direction in sequence, thereby displaying the light L flowing in the X direction at the output part 32. The spacing D2 between the LEDs 22 in the central part CP in the X direction is wider than the spacing D1 between the LEDs 22 at both ends. The control device 5 lights up the LEDs 22 in the central part CP and the LEDs 22 at both ends EP1 and EP2 at lighting timings corresponding to their respective spacings D2 and D2.

Description

Technical Field

[0001] The present invention relates to a display device.

Background Art

[0002] A display device provided in a vehicle displays light flowing in a certain direction, for example, for decoration or attention - getting. The display device includes a plurality of light sources arranged side by side at regular intervals. The display device can make a user visually recognize that light is flowing by lighting the plurality of light sources in order from one end to the other end (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a display device, by narrowing the arrangement interval of light sources and arranging them densely, a more natural light flow can be displayed. However, an increase in the number of installed light sources may lead to an increase in the installation cost of the display device. In a display device, it is required to display a natural light flow while reducing the installation cost.

Means for Solving the Problems

[0005] The display device according to the present invention a plurality of light sources arranged side by side in a first direction, a light guide plate having an incident portion arranged to face the plurality of light sources in a second direction intersecting the first direction, where the light irradiated by the plurality of light sources is incident, and an exit portion that exits the light incident on the incident portion. The system includes a control unit that sequentially lights up the plurality of light sources in the first direction, thereby causing the emission unit to display light flowing in the first direction, The spacing of the light sources in the central part in the first direction is wider than the spacing of the light sources at one end and the other end in the first direction. The control unit illuminates the central light source and the light sources at one end and the other end at illumination timings corresponding to their respective spacings. [Effects of the Invention]

[0006] According to the present invention, it is possible to display a natural flow of light while reducing installation costs. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows an example of the arrangement of the display device according to the embodiment. [Figure 2] This is a schematic diagram showing the configuration of a display device. [Figure 3] This is a schematic diagram showing the arrangement of the LED and light guide plate when viewed from the Z direction. [Figure 4] This figure shows the schematic circuit configuration of the display device. [Figure 5] This is a timing chart showing an example of the input timing of the PWM signal in this embodiment. [Figure 6] This figure shows the correspondence between the LED lighting state and the light visible at the emission point, based on the timing chart in Figure 5. [Figure 7] This is a diagram of Comparative Example 1. [Figure 8] This figure shows Comparative Example 2. [Modes for carrying out the invention]

[0008] Hereinafter, a display device according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 shows an example of the arrangement of the display device 1 according to the embodiment. Figure 2 is a schematic diagram showing the configuration of the display device 1. Figure 2 schematically shows a cross-section of the display device 1 cut along the Y direction. As shown in Figure 1, the display device 1 can be installed, for example, on an instrument panel 100 installed in a vehicle such as an automobile. The drawing shows the directions (X, Y, Z directions) based on the installation state of the display device 1 on the instrument panel 100. The "Z direction" corresponds to the vertical direction. The "X direction" is perpendicular to the Z direction and corresponds to the vehicle width direction. The "Y direction" is perpendicular to both the Z and X directions and corresponds to the vehicle's longitudinal direction. In the following explanation, when we say "along the X, Y, or Z direction," we are not limited to cases where it is strictly parallel to the X, Y, or Z direction, but also include cases where it is slightly tilted.

[0009] The instrument panel 100 is a cover member that covers the front side of the vehicle interior VR. The instrument panel 100 has a side portion 101 and a top portion 102. The side portion 101 extends along the Z and X directions and faces the driver's seat and passenger seat (not shown) in the vehicle interior VR in the Y direction. Although not shown in detail, various devices such as instruments, control switches, a main display, and audio equipment are arranged on the side section 101. The steering wheel switches are located in the area of ​​the side section 101 facing the driver's seat. A steering member (not shown) is provided inside the instrument panel 100, and the steering wheel switches are supported by the steering member via a steering shaft (not shown).

[0010] The upper portion 102 connects to the upper end of the side portion 101 and extends along the X and Y directions. The upper portion 102 has a first upper portion 103 connected to the upper end of the side portion 101 and a second upper portion 104 located on the Y1 side (vehicle front side, see Figure 2) of the first upper portion 103. As shown in FIG. 2, the second upper surface portion 104 is arranged offset upward in the Z direction with respect to the first upper surface portion 103 when viewed from the Y direction. Also, when viewed from the Z direction, the end portion 103a on the Y1 side of the first upper surface portion 103 overlaps the end portion 104a on the Y2 side of the second upper surface portion 104. As a result, a slit 105 that opens in the Y direction is formed between the end portion 103a on the Y1 side of the first upper surface portion 103 and the end portion 104a on the Y2 side of the second upper surface portion 104. The interior of the instrument panel 100 communicates with the vehicle cabin VR through the slit 105.

[0011] As shown in FIG. 2, the display device 1 is arranged at a position inside the instrument panel 100 facing the slit 105. The light L irradiated by the display device 1 is visible from inside the vehicle cabin VR through the slit 105. The light L of the display device 1 can be used, for example, for decorating the vehicle cabin VR or attracting the driver's attention.

[0012] As shown in FIG. 1, as an example, the display device 1 displays a spot-shaped light L flowing in the X direction. In the drawing, an example is shown in which the display device 1 displays the light L flowing from the X1 side to the X2 side, but the display device 1 may display the light L flowing from the X2 side to the X1 side.

[0013] As shown in FIG. 2, the display device 1 includes an LED (light emitting diode) module 2, a light guide plate 3, and a diffusion plate 4. The LED module 2 includes a thin plate-shaped LED substrate 21 and a plurality of LEDs (light sources) 22 mounted on the LED substrate 21. The LED substrate 21 is arranged with its longitudinal direction along the X direction and has, for example, a length in the X direction corresponding to the slit 105 of the instrument panel 100. The plurality of LEDs 22 are arranged on the LED substrate 21 at intervals in the X direction. Each LED 22 is arranged to irradiate the light L toward the Y2 side where the slit 105 is located. Although not shown in the figure, circuit components other than the LEDs 22 are also arranged on the LED substrate 21.

[0014] The light guide plate 3 and the diffusion plate 4 are arranged between the LED substrate 21 and the slit 105 in the Y direction. The light guide plate 3 includes an incident portion 31 on the Y1 side where the LED substrate 21 is located, and an exit portion 32 on the Y2 side where the slit 105 is located. The incident portion 31 is arranged to face the LED substrate 21, and the light L irradiated by the LED 22 enters. The light guide plate 3 includes a guide portion 33 that guides the light L between the incident portion 31 and the exit portion 32. The light L incident on the incident portion 31 passes through the guide portion 33 and is emitted from the exit portion 32.

[0015] The diffusion plate 4 is arranged on the Y2 side of the exit portion 32 of the light guide plate 3. The diffusion plate 4 can be formed, for example, in a C-shaped cross-section and arranged to cover the exit portion​​​​​​​​​​​​​As shown in Figure 3, the N LEDs 22 that make up the LED module 2 are arranged along the X direction. In the drawing, the N LEDs 22 are numbered #1, #2, #3...#(N-1), #(N) in order from the X1 side. LED module 2 has LEDs 22 positioned at the X1 end EP1 (one end), the X2 end EP2 (the other end) in the X direction, and the central part CP. In the following explanation, when referring to the X1 end EP1 and the X2 end EP2 together, they will be referred to as "both ends EP1 and EP2".

[0018] The number of LED22s placed in each region is not limited, but in the illustrated example, two LED22s (#1, #2, #(N-1), #(N)) are placed at the X1 end EP1 and the X2 end EP2, respectively. The remaining LED22s (#3 to #(N-2)) are placed in the central part CP. The LEDs 22 located at both ends EP1 and EP2 (#1, #2, #(N-1), #(N)) are arranged with a spacing of D1. The LEDs 22 located at the center CP (#3~#(N-2)) are arranged with a spacing of D2. Here, "arrangement interval" can be defined as, for example, the distance from the center of each LED22 in the X direction to the center of an adjacent LED22 in the X direction. The spacing D2 is longer than the spacing D1 (D2 > D1). That is, in LED module 2, the LEDs 22 at both ends EP1 and EP2 (#1, #2, #(N-1), #(N)) are arranged with a narrow spacing D1, while the LEDs 22 at the central part CP (#3 to #(N-2)) are arranged with a wide spacing D2. Furthermore, the spacing D3 between LED22#2, located furthest towards X2 at the X1 end EP1, and LED22#3, located furthest towards X1 at the central CP, is longer than the spacing D1 (D3 > D1). Also, the spacing D3 between LED22#(N-2), located furthest towards X2 at the central CP, and LED22#(N-1), located furthest towards X1 at the X2 end EP2, is also longer than the spacing D1 (D3 > D1).

[0019] The spacing D1 between the end sections EP1 and EP2 can be set, for example, so that a portion of the illumination range of the light L emitted by adjacent LEDs 22 overlaps in the emission section 32. The spacing D2 between the central section CP can be set, for example, so that the illumination ranges of the light L emitted by adjacent LEDs 22 within the same area do not overlap in the emission section 32.

[0020] Furthermore, the LEDs 22 (#3~#(N-2)) of the central CP are offset to the Y1 side (vehicle front side) relative to the LEDs 22 (#1, #2, #(N-1), #(N)) of both ends EP1 and EP2. As a result, the distance L2 between the LEDs 22 (#3~#(N-2)) of the central CP and the light-emitting part 32 of the light guide plate 3 is longer than the distance L1 between the LEDs 22 (#1, #2, #(N-1), #(N)) of both ends EP1 and EP2 and the light-emitting part 32 (L2>L1). In addition, in LED module 2, the LED board 21 (see Figure 2) can be bent towards the Y1 side at the central part CP, thereby offsetting the LEDs 22 (#3 to #(N-2)) at the central part CP towards the Y1 side. Alternatively, in LED module 2, the LED board 21 can be divided into the central part CP and the end parts EP1 and EP2, and the LED board 21 at the central part CP can be offset relative to the LED boards 21 at the end parts EP1 and EP2.

[0021] As shown in Figure 3, the incident portion 31 of the light guide plate 3 has a protrusion 34 that projects toward the LED 22 side (Y1 side). Each of the N LEDs 22 is formed corresponding to one of the N LEDs 22. The protrusion 34 can have a tapered shape, for example, tapering from the base on the Y2 side toward the top on the Y1 side facing each LED 22. As described above, the LEDs 22 (#3~#(N-2)) of the central CP are offset to the Y1 side relative to the LEDs 22 (#1, #2, #(N-1), #(N)) of both ends EP1 and EP2. In accordance with this arrangement of LEDs 22, the protrusions 34 facing the LEDs 22 (#3~#(N-2)) of the central CP and the protrusions 34 facing the LEDs 22 (#1, #2, #(N-1), #(N)) of both ends EP1 and EP2 are formed to have different heights in the Y direction. Specifically, the protrusions 34 facing the LEDs 22 (#1, #2, #(N-1), #(N)) of both ends EP1 and EP2 have a height H1 from the base on the Y2 side to the tip on the Y1 side. The protrusion 34 facing the LED22 (#3~#(N-2)) of the central CP has a height H2 from the base on the Y2 side to the tip on the Y1 side. Height H2 is greater than height H1 (H2>H1).

[0022] The illumination range of the light L emitted by LED22 widens as the distance it travels increases. The distance L2 that the light L emitted by LED22 (#3~#(N-2)) in the central part CP travels before being emitted from the emission part 32 of the light guide plate 3 is longer than the distance L1 that the LED22 (#1, #2, #(N-1), #(N)) at both ends EP1 and EP2 travel. Therefore, the width W2 of the illumination range at the emission part 32 of the light L emitted by LED22 (#3~#(N-2)) in the central part CP is wider than the width W1 of the illumination range of the light L emitted by LED22 (#1, #2, #(N-1), #(N)) at both ends EP1 and EP2 (W2>W1). Here, the LEDs 22 (#1, #2, #(N-1), #(N)) at both ends EP1 and EP2 have light L illumination ranges that partially overlap with adjacent LEDs 22. For example, as shown in Figure 3, when LEDs 22 #1 and #2 at end EP1 on the X1 side are lit simultaneously, a total light L of width W3 is visible (W3 > W1). Width W3 is wider than width W1.

[0023] The intensity (Iv) of the light L emitted by LED22 decreases with distance from the light source. Therefore, if all LED22 of LED module 2 emit light L of the same intensity, the LED22 at the center CP at a distance L2 from the emission part 32 (#3~#(N-2)) will have a weaker light L intensity at the emission part 32 than the LED22 at both ends EP1 and EP2 at a distance L1 (#1, #2, #(N-1), #(N)) (L2>L1, Iv2). <Iv1)。

[0024] Furthermore, when the LEDs 22 arranged in the X direction of the LED module 2 are lit sequentially from the X1 side or the X2 side, the light L appears to flow in the X direction at the emission section 32. Here, if all LEDs 22 are lit at the same time interval, the longer the distance in the X direction between adjacent LEDs 22, the faster the light L appears to flow at the emission section 32. Specifically, at the central CP, which is set to spacing D2, the light L appears to flow faster than at the end points EP1 and EP2, which are set to spacing D1 (D2 > D1, V2 > V1).

[0025] Figure 4 shows a schematic circuit configuration of the display device 1. As shown in Figure 4, the display device 1 includes a control device 5 that controls the lighting and extinguishing of N LEDs 22 provided on the LED module 2. The control device 5 can be, for example, an ECU (Electronic Control Unit) that controls the operation of the vehicle. Although details are omitted, the control device 5 can, for example, control the LEDs 22 in response to user switch operations. Alternatively, the control device 5 may detect the user's driving status using sensors or the like and control the LEDs 22 based on the detection results.

[0026] As shown in Figure 4, each LED 22 (#1 to #(N)) of the LED module 2 is connected to a power source PS such as a battery and ground GD via connecting wires 61 and 62. Connecting wire 61 is connected to the power source PS at one end and to the connecting wire 62 provided for each LED 22 at the other end. Connecting wire 62 is connected to connecting wire 61 at one end and to ground GD at the other end. Each LED 22 is provided on connecting wire 62. A switch 63 is provided between LED22 and ground GD in each connection line.

[0027] The switch 63 can be made up of, for example, a transistor, an FET (Field-Effect Transistor), or the like. Figure 4 shows an example where switch 63 is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). An N-channel MOSFET is a transistor that turns on when a voltage is applied to the gate electrode (G), causing current to flow between the source electrode (S) and the drain electrode (D). An N-channel MOSFET turns on when the voltage applied to the gate electrode (G) (gate voltage) is at a high level and turns off when it is at a low level.

[0028] Switch 63 has its drain electrode (D) on the power supply PS side and its source electrode (S) on the ground GD side in the connection line 62, and its gate electrode (G) is connected to the control device 5 via the signal line 64. The control device 5 inputs an on / off control signal to each switch 63. When switch 63 is turned on, current is supplied from the power supply PS to the LED 22, and the LED 22 lights up. When switch 63 is turned off, the current supply from the power supply PS to the LED 22 is cut off, and the LED 22 turns off.

[0029] The control device 5 can receive, for example, a PWM signal as a control signal to switch the switch 63 on and off. A PWM signal is a signal obtained by modulating the pulse width of a pulse signal. As shown in Figure 4, a PWM signal includes periods in one pulse period P where the voltage (V) is at a high level and periods where it is at a low level. The proportion of the period Ph in one pulse period P where the voltage is at a high level is the duty cycle D. The control device 5 can display a spot-shaped light L flowing in the X direction, as shown in Figure 1, by adjusting the input timing of the PWM signal to each LED 22 and the duty cycle D.

[0030] Figure 5 is a timing chart showing an example of the input timing of the PWM signal in this embodiment. Figure 6 shows the correspondence between the lighting state of LED 22 and the light L emitted from the emission unit 32, based on the timing chart in Figure 5. In Figure 6, the lit state of LED 22 and the light L visible from the emission unit 32 are hatched. Note that in Figure 6, for simplification, all LEDs 22 are shown aligned in a straight line. Also, as mentioned above, the light L emitted by the emission unit 32 is diffused by the diffuser plate 4 (see Figure 2) and visible to the user. However, for the sake of simplification, in the explanation using Figure 6, the user is assumed to directly see the light L emitted by the irradiation unit 32.

[0031] As shown in Figure 5, the control device 5 sequentially inputs PWM signals to the N LEDs 22 #1 to #(N) from time t1 to time tn. As shown in Figure 1, when the display device 1 displays light L flowing from the X1 side to the X2 side, the control device 5 inputs PWM signals to the LEDs 22 in each region in the following order: LEDs 22 (#1, #2) at the X1 side end EP1, LEDs 22 (#3 to #(N-2)) at the central part CP, and LEDs 22 (#(N-1), #(N)) at the X2 side end EP2.

[0032] As described above, the LEDs 22 are arranged at different spacings D1 and D2 (see Figure 3) at both ends EP1 and EP2 and at the central part CP. The control device 5 lights up the LEDs 22 at both ends EP1 and EP2 and at the central part CP at lighting timings corresponding to the respective spacings D1 and D2. Specifically, as shown in Figure 5, the control device 5 inputs a PWM signal to the LEDs 22 at both ends EP1 and EP2 at a time interval Ta (first time interval). The control device 5 also inputs a PWM signal to the LED 22 at the center CP at a time interval Tb (second time interval). The time interval Tb is longer than the time interval Tb (Tb > Ta).

[0033] Furthermore, the control device 5 sets the duty cycle D of the PWM signal input to the LED 22 to be different for the end sections EP1 and EP2 and the central section CP. The control device 5 inputs a PWM signal with a duty cycle Da (the period during which the voltage level is high Pha / pulse period P) to the LEDs 22 at both ends EP1 and EP2. The control device 5 also inputs a PWM signal with a duty cycle Db (the period during which the voltage level is high Phb / pulse period P) to the LED 22 at the center CP. Here, since the period Phb is set to be longer than the period Pha, the duty cycle Db is greater than the duty cycle Da (Db > Da).

[0034] The following describes the processing of the control device 5 at each point in time. As shown in Figure 5, at the initial time point t1, the control device 5 inputs a PWM signal with duty cycle Da to the LED22#1 (first light source) located closest to X1 at the X1 end EP1. At time t2, which is the next time interval Ta from time t1, the control device 5 inputs a PWM signal with duty cycle Da to LED22#1 and LED22#2 (the second light source) adjacent to the X2 side of LED22#1. As shown in Figure 6, at time t1, LED22#1 is lit individually, making it appear as if a light L with width W1 is generated at the X1 side end EP1 of the emission section 32. At the next time point t2, LEDs 22#1 and #2 are lit simultaneously. The light L from LEDs 22#1 and #2 partially overlap, and the overall visible light L is width W3 (W3 > W1). Width W3 is wider than width W1. In other words, the light L with width W1 generated at the X1 end EP1 at time t1 is expanded to width W3 at time t2 and appears to flow out towards the X2 side.

[0035] As shown in Figure 5, at time t3, which follows time t2, the input target of the PWM signal shifts from the X1 end EP1 to the central part CP. At time t3, which is a time interval Tc from time t2, the control device 5 inputs a PWM signal with a duty cycle Db to LED22#3, which is adjacent to the X2 side of LED22#2. Here, the time interval Tc is set to be longer than the time interval Ta (Tc > Ta).

[0036] At time t4, which is a time interval Tb from time t3, the control device 5 inputs a PWM signal with a duty cycle Db to LED22#4, which is adjacent to the X2 side of LED22#3. Although not shown in the diagram, the control device 5 subsequently inputs a PWM signal with a duty cycle of Db to the LED 22 of the central CP at time intervals Tb.

[0037] As shown in Figure 6, at time t3, LEDs 22#1 and #2 at the X1-side end EP1 are turned off, and LED 22#3 at the central part CP adjacent to LED 22#2 is turned on. As a result, the user can see that light L is flowing from the X1-side end EP1 of the emission section 32 to the central part CP. When LEDs 22#3~#(N-2) in the central CP are lit, a light beam of width W2 is visible in the emitter 32. The width W2 can be adjusted as needed by setting the spacing D1 and D2 between the LEDs 22 and the distances L1 and L2 from the emitter 32, for example, so that it is close in length to the width W3. This allows the user to see a natural flow of light L from the X1 end EP1 of the emitter 32 to the central CP.

[0038] Furthermore, as mentioned above, the spacing of the LEDs 22 differs between the central part CP and the end EP1 on the X1 side (D2 > D1, see Figure 3). Therefore, when a PWM signal is input to all LEDs 22 in these regions at the same time interval Ta, the speed of light L flowing at the central part CP of the output section 32, V2, becomes faster than the speed of light L flowing at the end EP1 on the X1 side, V1, as shown in the following equation (V2 > V1). • The speed at which light L flows at the X1 end EP1 is V1 = D1 / Ta • The speed at which light L flows through the central CP is V2 = D2 / Ta In this case, the user may perceive a sudden change in the speed of the light L flowing through the emission unit 32, potentially resulting in an unnatural flow of light.

[0039] Therefore, as shown in Figure 5, the control device 5 makes the time interval Tb for inputting the PWM signal at the central part CP longer than the time interval Ta at both ends EP1 and EP2 (Tb > Ta). As a result, in this embodiment, the light flow speeds V1 and V2 at the emission part 32 are as shown by the following equations. • The speed at which light L flows at the X1 end EP1 is V1 = D1 / Ta • The speed at which light L flows through the central CP is V2 = D2 / Tb By appropriately adjusting the time intervals Ta and Tb according to the placement intervals D1 and D2, the speeds V1 and V2 can be made to be close (V1 ≈ V2).

[0040] Furthermore, by appropriately adjusting the time interval Tc between time points t2 and t3 according to the spacing D3 between LED22#2 and LED22#3, it is possible to make the speed V3 at which the light L flows from the end EP1 on the X1 side to the central part CP close to speeds V1 and V2 (V1≒V2≒V3). This allows the user to visualize a smooth and natural flow of light L from the X1 end EP1 of the emission section 32 to the central section CP.

[0041] Furthermore, as mentioned above, the LEDs 22 (#3~#(N-2)) in the central CP are offset towards the Y1 side compared to the LEDs 22 #1 and #2 in the X1 end EP1, and are further away from the light-emitting section 32 (see Figure 3, L2>L1). Therefore, if the LEDs 22 in the central CP and the LEDs 22 in both ends EP1 and EP2 emit light L of the same intensity, the user will perceive the intensity of the light L as it moves from the X1 end EP1 to the central CP (Iv2). <Iv1)。

[0042] When controlling the illumination of LED22 with a PWM signal, the intensity of light L can be increased by increasing the duty cycle D. As shown in Figure 5, the control device 5 sets the duty cycle Db of the PWM signal input to LED22 (#3~#(N-2)) in the central part CP to be greater than the duty cycle Da of the PWM signal input to LED22#1 and #2 at the end EP1 on the X1 side. The specific settings of duty cycles Da and Db can be appropriately set according to the distances L1 and L2 from the light output section 32.

[0043] By increasing the intensity of the light L emitted by the LED22 (#3~#(N-2)) in the central CP, even at a distance from the emission unit 32, the emission unit 32 can make the light L of a similar intensity to that of the end EP1 on the X1 side visible (Iv2≒Iv1). This allows the user to perceive a natural flow of light L from the end EP1 on the X1 side to the central CP. Furthermore, the method for increasing the intensity of light L is not limited to increasing the duty cycle D; for example, the amount of current supplied from the power supply PS (see Figure 4) may also be increased.

[0044] As shown in Figure 5, at time t(N-2), the control device 5 inputs a PWM signal to LED22#(N-2), which is located on the X2 side of the central CP. At the next time point (N-1), the target of the PWM signal input shifts from the central CP to the X2 side end EP2. At time t(N-1), which is a time interval Tc from time t(N-2), the control device 5 inputs a PWM signal at the same time to LED22#(N-1) (the fourth light source) and LED22#(N) (the third light source) located at the X2 end EP2. The PWM signals input to LED22#(N-1) and #(N) are set to a duty cycle of Da, similar to the PWM signal input to LED22 at the X1 end EP1. The control device 5 inputs a PWM signal with duty cycle Da to the LED22#(N) located furthest towards X2 at the last time point t(N) after a time interval Ta from time point t(N-1).

[0045] As shown in Figure 6, at time t(N-2), LED22#(N-2), which is located closest to X2 in the central part CP, lights up, and a light L with a width of W2 is visible in the emission part 32. At the next time point t(N-1), LEDs 22#(N-1) and #(N) at the X2 end EP2 are lit simultaneously, making the overall light L of width W3 visible (W3>W1). As mentioned above, width W3 is set to be close to width W2. This allows the user to visualize the natural flow of light L from the central part CP of the emission section 32 to the end EP2 on the X2 side. Then, at the final point in time t(N), LED22#(N) is lit up by itself. In other words, the user perceives that the light L flowing from the central part CP to the end EP2 on the X2 side shrinks from width W3 to width W1 and then disappears.

[0046] Furthermore, at the X2 end EP2, similar to the X1 end EP1, the spacing D1 of the LEDs 22 is narrower than the spacing D2 of the central CP. Therefore, the control device 5 inputs a PWM signal to LEDs 22#(N-1) and #(N) at the X2 end EP2 with a time interval Ta shorter than the time interval Tb, similar to the X1 end EP1. As a result, the speed V2 of light L flowing through the central CP and the speed V1 of light L flowing through the X2 end EP2 are close (V1 ≈ V2). Furthermore, by appropriately adjusting the time interval Tc between time point t(N-2) and time point t(N-1) when transitioning from the central part CP to the end EP2 on the X2 side, according to the interval D3 between LED22#(N-2) and LED22#(N-1), it is possible to make the speed V3 at which light L flows from the end EP1 on the X1 side to the central part CP close to speeds V1 and V2 (V1≒V2≒V3). This allows the user to visually perceive a smooth flow of light L from the central part CP of the emission section 32 to the end EP2 on the X2 side.

[0047] Furthermore, the duty cycle Da of the PWM signal input to LED22#(N-1) and #(N) at the X2 end EP2 is set to be smaller than the duty cycle Db, similar to the X1 end EP1. This allows light L of a similar intensity to that of the central part CP to be visible at the X2 end EP2 of the emission section 32 (Iv1 ≈ Iv2).

[0048] When the display device 1 repeatedly displays the flow of light L from the X1 side to the X2 side at the emission unit 32, the control device 5 can repeatedly input PWM signals from time t1 to time t(N).

[0049] Figure 7 shows Comparative Example 1. As shown in Figure 7, in Comparative Example 1, N' LEDs 22 are arranged at an interval D1. The interval D1 corresponds to the interval at both ends EP1 and EP2 in the embodiment (see Figure 6). That is, in Comparative Example 1, all LEDs 22 are arranged at a narrow interval D1, without distinction between the central part CP and both ends EP1 and EP2 in the X direction. In Comparative Example 1, the width of the light L illumination range at the emitter 32 of each LED 22 is W1. Also, when adjacent LEDs 22 are lit simultaneously, the illumination ranges of their respective light L partially overlap, and a light L with a width W3 is visible at the emitter 32.

[0050] In Comparative Example 1, the control device 5 sequentially inputs PWM signals to N' LEDs 22 from the X1 side to the X2 side at the same time interval Ta. All PWM signals are set to the same duty cycle Da. At the initial time point t1, the control device 5 lights up the LED 22 closest to X1 alone, and at the final time point, it lights up the LED 22 closest to X2 alone. Between time points t2 and t(N'-1), the control device 5 lights up two adjacent LEDs 22 simultaneously. As a result, in Comparative Example 1, at time t1, the light L with width W1 generated at the X1 side end EP1 of the emission section 32 expands to width W3 at time t2 and flows to the X2 side. At time t(N'), the light L shrinks from width W3 to width W1 and disappears. In other words, in Comparative Example 1, a natural flow of light L can be displayed, similar to the embodiment in Figure 6. However, in Comparative Example 1, all LEDs 22 are arranged at a narrow spacing D1, so the number of LEDs 22 installed increases compared to the embodiment (N'>N). This may increase the installation cost of the display device 1.

[0051] Figure 8 shows Comparative Example 2. As shown in Figure 8, in Comparative Example 2, N'' LEDs 22 are arranged with a spacing D2. The spacing D2 corresponds to the spacing of the central part CP in the embodiment (see Figure 6). In other words, in Comparative Example 1, all LEDs 22 are arranged with a wide spacing D2, without distinction between the central part CP and the end parts EP1 and EP2 in the X direction. In Comparative Example 2, all LEDs 22 are arranged with a wide spacing D2, so the number of LEDs 22 installed N'' is reduced compared to Comparative Example 1 (N''). <N’)。 However, in Comparative Example 2, the width of the light L irradiation area at the emission part 32 of each LED 22 is W2, and even when adjacent LEDs 22 are lit simultaneously, the irradiation areas of each light L do not overlap.

[0052] Therefore, as shown in Figure 8, in Comparative Example 2, the control device 5 lights each LED 22 individually at all time points t1 to t(N''). In other words, in Comparative Example 2, the width of light L cannot be expanded or contracted when light L is generated and extinguished. In Comparative Example 2, at the first time point t1, light L with width W2 is generated at the end EP1 on the X1 side, flows to the X2 side while maintaining width W2, and at the last time point t(N''), it disappears at the end EP2 on the X2 side while maintaining width W2. Therefore, in Comparative Example 2, it is not possible to display a natural flow of light L as in the embodiment (see Figure 6) or Comparative Example 1 (see Figure 7), and the user may perceive the appearance and disappearance of light L as abrupt.

[0053] In the display device 1 of this embodiment, as shown in Figure 3, only the LEDs 22 (#3 to #(N-2)) in the central part CP are arranged with a wide spacing D2. As a result, the number of LEDs 22 installed N is reduced compared to the number of LEDs N' installed in Comparative Example 1 in Figure 7 (N <N’)。 In this embodiment, the LEDs 22 (#3~#(N-2)) of the central CP are offset to the Y1 side compared to the LEDs 22 (#1, #2, #(N-1), #(N)) of the end sections EP1 and EP2. As a result, the distance L2 from the LEDs 22 (#3~#(N-2)) of the central CP to the emission section 32 is longer than the distance L1 from the end sections EP1 and EP2. Consequently, the width W2 of the light illumination range W2 at the central CP of the emission section 32 is wider than the width W1 of the illumination range W1 at the end sections EP1 and EP2. Even if the number of LEDs 22 installed in the central CP is reduced, each LED 22 (#3~#(N-2)) of the central CP can cover a wide illumination range.

[0054] Furthermore, the control device 5 of the display device 1 inputs a PWM signal to the LEDs 22 at both ends EP1 and EP2 at a time interval Ta, and to the LED 22 at the central part CP at a time interval Tb (Tb>Ta). This allows the user to perceive that the light L flows at the central part CP of the emission section 32 at a speed close to that of the ends EP1 and EP2 (V1≒V2).

[0055] Furthermore, the control device 5 inputs a PWM signal with duty cycle Da to the LEDs 22 (#1, #2, #(N-1), #(N)) at both ends EP1 and EP2, and a PWM signal with duty cycle Db (Db>Da) to the LEDs 22 (#3~#(N-2)) at the center CP. As a result, the light L emitted by the LEDs 22 at the center CP becomes stronger than that emitted by the LEDs 22 at both ends EP1 and EP2. Even when the distance L2 between the LEDs 22 at the center CP and the emitter 32 is greater than the distance L1 between the emitter 32 at both ends EP1 and EP2, the light L can be made visible at a similar intensity at the emitter 32 (Iv1≒Iv2).

[0056] Furthermore, in this embodiment, the LEDs 22 (#1, #2, #(N-1), #(N)) at both ends EP1 and EP2 are arranged with a narrow spacing D1. The illumination range of the light L emitted by each LED 22 (#1, #2, #(N-1), #(N)) at the emission section 32 partially overlaps with the illumination range of the adjacent LED 22. As a result, when the LEDs 22 at both ends EP1 and EP2 are lit individually, a light L with a width of W1 is visible at the emission section 32, and when two adjacent LEDs 22 are lit simultaneously, a light L with a width of W3, close to width W2, is visible at the emission section 32. Then, at the X1 end EP1, the control device 5 lights up LED22#1 alone at the first time point t1, and then lights up LED22#1 and LED22#2 simultaneously at the next time point t2. At the X2 end EP2, at the time point t(N-1) one step before the last time point t(N), LED22#(N-2) and #(N) are lit simultaneously, and then at the last time point t(N), LED22#(N) is lit alone. As a result, the display device 1 allows the user to visually perceive the natural generation and disappearance of light L at the X1-side end EP1 and the X2-side end EP2 of the emission unit 32. Furthermore, the user can visually perceive that light L of the same width (W2 ≈ W3) is flowing at both ends EP1 and EP2 and the central part CP of the emission unit 32. Thus, the display device 1 of this embodiment can reduce installation costs by reducing the number of LEDs 22 installed, while having display performance that allows the user to perceive a natural flow of light L.

[0057] As described above, the display device 1 according to this embodiment has, for example, the following configuration. (1) The display device 1 comprises an LED module 2, a light guide plate 3, and a control device 5 (control unit). The LED module 2 has N LEDs 22 (multiple light sources) arranged in the X direction (first direction) on the LED substrate 21. The light guide plate 3 has an incident section 31 and an outgoing section 32. The incident section 31 is positioned opposite the LED 22 in the Y direction (second direction) perpendicular (intersecting) to the X direction, and the light L emitted by the LED 22 is incident on it. The outgoing section 32 emits the light L that has been incident on the incident section 31. The control device 5 lights up N LEDs 22 sequentially in the X direction, thereby displaying light L flowing in the X direction at the emission unit 32. The spacing D2 of the LED22 (#3~#(N-2)) in the central CP in the X direction is wider than the spacing D1 of the LED22 (#1, #2, #(N-1), #(N)) in the X1 side end EP1 (one end) and the X2 side end EP2 (the other end) in the X direction. The control device 5 lights up the LEDs 22 (#3 to #(N-2)) in the central section CP and the LEDs 22 (#1, #2, #(N-1), #(N)) in the X1 end EP1 and the X2 end EP2, respectively, at lighting timings corresponding to their respective spacings D2 and D1.

[0058] By configuring it in this way, the display device 1 can display a natural flow of light L while reducing installation costs. In the display device 1, the narrower the spacing between the LEDs 22 in the LED module 2, the easier it is to display a natural flow of light L in the X direction. However, increasing the number of LEDs 22 may lead to increased installation costs. In this embodiment, the spacing D2 of LEDs 22 (#3 to #(N-2)) in the central part CP of LED module 2 is set wider than the spacing D1 of LEDs 22 (#1, #2, #(N-1), #(N)) in both end parts EP1 and EP2. As a result, the number of LEDs 22 (#3 to #(N-2)) to be installed in the central part CP is reduced, thereby reducing the increase in installation costs. Even if the arrangement spacing D2 of the LEDs 22 in the central section CP is widened, it is possible to widen the illumination range in the emission section 32, for example, and make the natural flow of light L visible. On the other hand, if the arrangement spacing of the LEDs 22 in both ends EP1 and EP2 is widened in the same way as in the central section CP, the generation and disappearance of light L may appear abrupt, which may affect the natural flow of light L. Therefore, in this embodiment, by arranging the LEDs 22 in both ends EP1 and EP2 at a narrow spacing D1, the generation and disappearance of light L can be displayed naturally. Furthermore, the control device 5 adjusts the lighting timing of each LED 22 according to the spacing D1 between the end sections EP1 and EP2 and the spacing D2 between the central section CP, thereby allowing the user to perceive a light flow L at the same speed even when the spacing is different.

[0059] (2) The distance L2 between the LED22 (#3~#(N-2)) of the central CP and the emission part 32 is longer than the distance L1 between the LED22 (#1, #2, #(N-1), #(N)) of the end EP1 on the X1 side and the end EP2 on the X2 side and the emission part 32. Specifically, the light guide plate 3 is positioned on the Y2 side of the LED module 2. The LEDs 22 (#3~#(N-2)) in the central part CP are positioned offset to the Y1 side in the Y direction relative to the LEDs 22 (#1, #2, #(N-1), #(N)) in the X1 side end EP1 and the X2 side end EP2.

[0060] With this configuration, the width W2 of the illumination range at the output section 32 of the light L emitted by the LED22 (#3~#(N-2)) of the central CP becomes longer than the width W1 of the illumination range of the light L emitted by the LED22 (#1, #2, #(N-1), #(N)) of both ends EP1 and EP2 (W2>W1). As a result, even if the number of LED22 installed in the central CP is reduced, each LED22 can cover a wide area.

[0061] The method for varying the irradiation range of light L in the emission section 32 between the LEDs 22 (#3~#(N-2)) in the central section CP and the LEDs 22 (#1, #2, #(N-1), #(N)) in both end sections EP1 and EP2 is not limited to this example. For example, a lens that diffuses the light L of the LEDs 22 may be placed in the emission section 32 of the light guide plate 3. The lens can be placed, for example, corresponding to each LED 22. For the LEDs 22 (#3~#(N-2)) in the central section CP, a lens with a greater diffusion rate than the LEDs 22 (#1, #2, #(N-1), #(N)) in both end sections EP1 and EP2 can be placed. In this case, the LEDs 22 (#3~#(N-2)) in the central section CP can be placed at the same position in the Y direction without being offset to the Y1 side relative to the LEDs 22 (#1, #2, #(N-1), #(N)) in both end sections EP1 and EP2.

[0062] (i) The incident portion 31 is provided with protrusions 34 formed to correspond to each opposing LED 22 in the Y direction. The height H2 in the Y direction of the protrusions 34 facing the LED 22 (#3 to #(N-2)) in the central portion CP is set to be higher than the height H1 of the protrusions 34 facing the LED 22 (#1, #2, #(N-1), #(N)) in the end EP1 on the X1 side and the end EP2 on the X2 side.

[0063] In this way, by forming protrusions 34 corresponding to each LED 22, which is positioned differently in the Y direction in the central part CP and both end parts EP1 and EP2, the light L emitted from the LED 22 in each region can be appropriately guided to the emission part 32.

[0064] (3) In the display device 1 of (1) or (2) above, The control device 5 controls the timing of the LED 22's illumination by inputting a PWM signal to the LED 22. The control device 5 sets the duty cycle Db of the PWM signal input to the LED22 (#3~#(N-2)) of the central CP to be greater than the duty cycle Da of the PWM signal input to the LED22 (#1, #2, #(N-1), #(N)) of the end EP1 on the X1 side and the end EP2 on the X2 side.

[0065] The distance L2 between the LED22 (#3~#(N-2)) in the central CP and the light-emitting part 32 is longer than the distance L1 between the LED22 (#1, #2, #(N-1), #(N)) in both ends EP1 and EP2 and the light-emitting part 32. Therefore, if all LED22 emit light L of the same intensity, the light L visible at the light-emitting part 32 will be weaker in the central CP than in the ends EP1 and EP2. The control device 5 sets the duty cycle Db of the PWM signal input to the LED22 (#3~#(N-2)) of the central CP to be greater than the duty cycle Da of the PWM signal input to the LED22 (#1, #2, #(N-1), #(N)) of the end EP1 on the X1 side. This makes the intensity Iv2 of the light L of the central CP visible at the emission unit 32 closer to the intensity Iv1 of the light L of the end EP1 and EP2 (Iv1 ≈ Iv2). As a result, the display device 1 can display a natural flow of light L.

[0066] (4) In any of the display devices 1 described in (1) to (3) above, The control device 5 inputs a PWM signal to the LEDs 22 at the X1 end EP1 and the X2 end EP2 at a time interval Ta (first time interval). The control device 5 inputs a PWM signal to the LED 22 of the central CP at a time interval Tb (second time interval) that is longer than the time interval Ta.

[0067] Because the spacing D2 of the LED22 (#3~#(N-2)) in the central section CP is different from the spacing D1 of the LED22 (#1, #2, #(N-1), #(N)) in both ends EP1 and EP2, when a PWM signal is input to all LED22 at the same time interval, the speed at which the light L flows in the output section 32 appears to change abruptly between the central section CP and both ends EP1 and EP2. In this embodiment, the control device 5 sets the time interval Tb for inputting the PWM signal to the LED 22 of the central part CP to be longer than the time interval Ta of the ends EP1 and EP2. This makes it possible to bring the speed of light L flowing at the central part CP and the ends EP1 and EP2 of the emission section 32 closer together (V2 ≈ V1). This allows the user to visually perceive a smooth flow of light L.

[0068] (5) In any of the display devices 1 described in (1) to (4) above, The control device 5 lights up N LEDs 22 sequentially from the X1 side (one end) to the X2 side (the other end) in the X direction at multiple time points t1 to t(N). The LED22 at the X1 end EP1 includes LED22#1 (first light source), which is located closest to X1 in the X direction, and LED22#2 (second light source), which is adjacent to LED22#1 on the X2 side (other end). LEDs 22#1 and #2 are positioned such that the illumination ranges of the light L emitted by each LED overlap in part at the light-emitting section 32. The control device 5 lights up LED22#1 by itself at the first time point t1 in a set of multiple time points t1 to t(N), and then lights up LED22#1 and LED22#2 simultaneously at time point t2 (the second time point) following the first time point t1.

[0069] With this configuration, the light L with width W1 generated at the X1 end EP1 in the emission section 32 expands to width W3 at time t2 and flows out to the X2 side, allowing the user to visually perceive the generation of natural light L.

[0070] (6) In any of the display devices 1 described in (1) to (5) above, The control device 5 lights up N LEDs 22 sequentially from the X1 side (one end) to the X2 side (the other end) in the X direction at multiple time points t1 to t(N). The LED22 at the X2 end EP2 includes LED22#(N) (third light source), which is located furthest towards X2 in the X direction, and LED22#(N-1) (fourth light source), which is adjacent to LED22#(N) on the X1 side. LEDs 22#(N) and #(N-1) are arranged such that the illumination ranges of the light L emitted by each LED overlap in part at the light emission section 32. The control device 5 simultaneously lights up LED22#(N) and #(N-1) at time t(N-1), which is one time point before the last time point t(N) in a series of time points t1 to t(N), and lights up LED22#(N) by itself at the last time point t(N).

[0071] With this configuration, the light L with width W3 that flows to the end EP2 on the X2 side of the emission section 32 shrinks to width W1 and disappears at the final time point t(N), allowing the user to visually perceive a natural disappearance of the light L. [Explanation of Symbols]

[0072] 1 Display device 2 LED modules 3 Light guide plate 5. Control device (control unit) 22 LED (light source) 31 Input part 33. Ejection section 34 Convex part L light CP center EP1 X1 side end (one end) EP2 X2 side end (other end)

Claims

1. Multiple light sources arranged in a line in the first direction, A light guide plate is arranged opposite to the plurality of light sources in a second direction intersecting the first direction, and has an incident section into which light irradiated by the plurality of light sources is incident, and an outgoing section into which light incident on the incident section is emitted. The system includes a control unit that causes the plurality of light sources to be sequentially lit in the first direction, thereby displaying light flowing in the first direction at the emission unit, The spacing of the light sources in the central part in the first direction is wider than the spacing of the light sources at one end and the other end in the first direction. The control unit is a display device that illuminates the central light source and the light sources at one end and the other end at illumination timings corresponding to their respective spacings.

2. In claim 1, A display device wherein the distance of the central light source to the emission part is longer than the distance of the light sources at one end and the other end to the emission parts.

3. In claim 1, The aforementioned light source is an LED, The control unit controls the timing of the LED's illumination by inputting a PWM signal to the LED. The control unit is a display device that makes the duty cycle of the PWM signal input to the central LED greater than the duty cycle of the PWM signal input to the LEDs at one end and the other end.

4. In claim 3, The control unit, The LEDs at one end and the other end are input to the PWM signal at a first time interval. A display device that inputs the PWM signal to the central LED at a second time interval longer than the first time interval.

5. In claim 1, The control unit illuminates the plurality of light sources sequentially from one end to the other in the first direction at multiple points in time. The light source at one end comprises a first light source located at the furthest end in the first direction, and a second light source adjacent to the other end of the first light source. The first light source and the second light source are arranged such that a portion of the illumination range of the light emitted by each of them overlaps in the emission section. The control unit is a display device that, at the first of the plurality of time points, lights up the first light source alone, and at a second time point following the first time point, lights up the first light source and the second light source simultaneously.

6. In claim 1, The control unit illuminates the plurality of light sources sequentially from one end to the other in the first direction at multiple points in time. The light source at the other end comprises a third light source located furthest to the other end in the first direction, and a fourth light source adjacent to one end of the third light source. The third light source and the fourth light source are arranged such that a portion of the irradiation range of the light emitted by each of them overlaps in the emission section. The control unit is a display device that simultaneously lights up the third light source and the fourth light source at the time immediately preceding the last of the multiple time points, and lights up the third light source alone at the last time point.

Images