JP5695891B2 - LED surface emitting device - Google Patents

Description

  The present invention includes a substantially rectangular light guide plate and an LED light source, and an incident surface on which light from the LED light source is incident is configured by a root side end surface of the light guide plate, and light guided by the light guide plate is emitted. The present invention relates to an LED surface light emitting device in which an emission surface is constituted by a front surface of a light guide plate, a prism cut is formed on a back surface of the light guide plate, and a rough surface processing is applied to the prism cut.

In particular, the present invention eliminates the need to independently control the energized state and the non-energized state of the plurality of LED light sources, and the state in which only a part of the exit surface of the light guide plate appears to emit light, LED surface that can emit light of a maximum of three colors without forming the state where the entire exit surface of the light plate appears to emit light , and further independently controlling the energized state and the non-energized state The present invention relates to a light emitting device.

  Conventionally, an approximately rectangular light guide plate and an LED light source are provided, and an incident surface on which light from the LED light source is incident is configured by a base side end surface of the light guide plate, and light emitted by the light guide plate is emitted. 2. Description of the Related Art An LED surface light emitting device is known in which a surface is constituted by one surface of a light guide plate, and a prism cut is formed on the other surface of the light guide plate. As an example of this type of LED surface light emitting device, for example, there is one described in Patent Document 1 (Japanese Patent Laid-Open No. 2009-283383).

  In the LED surface light emitting device described in Patent Document 1, a plurality of LED light sources are provided. Further, by turning on only a part of the plurality of LED light sources, it is possible to form a state in which only a part of the emission surface of the light guide plate appears to emit light (Patent Document 1). FIG. 2). Furthermore, by turning on all the LED light sources, it is possible to form a state in which the entire light exit surface of the light guide plate appears to emit light.

  In other words, in the LED surface light emitting device described in Patent Document 1, a state in which only a part of the exit surface of the light guide plate appears to emit light and the entire exit surface of the light guide plate emits light. In order to form a state that looks like this, it is necessary to provide a plurality of LED light sources.

  Further, in the LED surface light emitting device described in Patent Document 1, only a part of the light exiting surface of the light guide plate appears to emit light, and the entire light exiting surface of the light guide plate emits light. In order to form a visible state, it is necessary to independently control the energized state and the non-energized state of the plurality of LED light sources.

JP 2009-283383 A

The present inventor does not control the energized state and the non-energized state of the plurality of LED light sources independently, and only a part of the exit surface of the light guide plate appears to emit light. LED surface that can emit light of a maximum of three colors without forming the state where the entire exit surface of the light plate appears to emit light , and further independently controlling the energized state and the non-energized state We conducted intensive research to develop a light emitting device.

As a result, the present inventor switches the energization amount for the LED light source from the non-energized state to the energized state at a low speed so that only a part of the exit surface of the light guide plate emits light when the energization amount for the LED light source is switched. state that looks like being able to instantaneously form a further after switching of the energization amount to the LED light source, can be whole emission surface of the light guide plate to form a state that appears to be light-emitting, further without independently controlling the energization state and the non-energized state, it was found Rukoto can emit light of maximum three colors.

That is, the present invention eliminates the need to independently control the energized state and the non-energized state of the plurality of LED light sources, and the state in which only a part of the exit surface of the light guide plate appears to emit light, entire exit surface of the optical plate can be formed and a state that appears to emit light, without further independently controlling the energization state and a non-conductive state, Ru can emit light of maximum three-color LED An object is to provide a surface light emitting device.

According to the first aspect of the present invention, the rectangular first light guide plate and the rectangular first light guide plate disposed on the back side of the first light guide plate and substantially parallel to the first light guide plate. In the surface light emitting device having the second light guide plate, the first LED light source, and the second LED light source, the first light guide plate includes a first incident surface, a first emission surface, and a first surface through surface. The first LED light source has a first prism surface and a first back surface passing surface, and the second light guide plate has a second incident surface, a second emission surface, and a second prism surface. Is provided at a position facing the first incident surface, the second LED light source is disposed at a position facing the second incident surface, and the first LED light source and the second LED light source are the first light guide. The first light exit surface is disposed to face each other across the light plate and the second light guide plate, Formed on at least a part of the front surface of the first light guide plate, the first surface through surface is formed on a surface of the front surface of the first light guide plate on which the first emission surface is not provided, The first back surface through-surface is formed at a position facing the first surface through-surface in the back-side surface of the first light guide plate, and the first prism surface is out of the back-side surface of the first light guide plate. The second light emitting surface is formed at a position facing the first back surface through surface of the front surface of the second light guide plate, and the second prism is formed at a position facing the first light emitting surface. The surface is formed at a position opposite to the second emission surface on the back surface of the second light guide plate, and is emitted from the first LED light source and enters the first light guide plate at the first incidence surface. Of the emitted light, the light reflected by the first prism surface The light emitted from the first emission surface to the outside and leaked from the first prism surface is directed to the second prism surface of the second light guide plate and the second prism surface to the second prism surface. Reflected to the exit surface, and finally emitted from the second exit surface, passes through the first back surface through surface and the first surface through surface of the first light guide plate and is emitted to the outside, The light emitted from the second LED light source and entering the second light guide plate at the second incident surface is reflected by the second prism surface to the second emitting surface, and finally the second emitting surface. Is transmitted through the first back surface through-surface and the first front surface through-surface of the first light guide plate to be emitted to the outside, and the energization amount to the first LED light source is de-energized at a first switching speed. 1st mode to switch from state to energized state And de, and the second mode for switching the energization amount to the conduction state from a non-energized state with a slow second switching speed than the first switching speed for the first 1LED light source, to maintain the current amount for the first 1LED light source energized However, a third mode for switching the energization amount to the second LED light source from the non-energized state to the energized state at the second switching speed is provided, and the first LED light source and the second LED light source emit light different from each other. There is provided an LED surface light emitting device that emits light of color .

According to the invention described in claim 2, one of the front side surface and the back side surface of the first light guide plate intersects with the optical axis of the first LED light source,
One of the front side surface and the back side surface of the second light guide plate intersects the optical axis of the second LED light source, and the front end surfaces of the first light guide plate located on the opposite side of the first incident surface are orthogonal to each other. 2. The LED surface according to claim 1, wherein the LED surface is configured by two planes, and a tip surface located on the opposite side of the second incident surface of the second light guide plate is configured by two planes orthogonal to each other. A light emitting device is provided.

In the LED surface light emitting device (10) according to claim 1, only a part of the exit surface of the light guide plate is controlled without independently controlling the energized state and the non-energized state of the plurality of LED light sources. A state in which light is emitted and a state in which the entire light exiting surface of the light guide plate appears to emit light are formed, and further, the energized state and the non-energized state are not controlled independently, and a maximum of 3 An LED surface light emitting device capable of emitting colored light is provided.

  In the LED surface emitting device (10) according to claim 3, one of the front side surface (3a2) and the back side surface (3a3) of the first light guide plate (3a) and the optical axis (1a ') of the first LED light source (1a). And are crossed. Therefore, according to the LED surface light emitting device (10) according to claim 3, the front surface (3a2) and the back surface (3a3) of the first light guide plate (3a) and the optical axis (1a) of the first LED light source (1a). ') Is reflected by the prism cut (3a3a1) on the back surface (3a3) of the first light guide plate (3a) out of the light emitted from the first LED light source (1a) than when not crossed. The ratio of light can be improved.

  Further, in the LED surface light emitting device (10) according to claim 3, one of the front side surface (3b2) and the back side surface (3b3) of the second light guide plate (3b) and the optical axis (1b) of the second LED light source (1b). ') Is crossed. Therefore, according to the LED surface light emitting device (10) according to claim 3, the front surface (3b2) and the back surface (3b3) of the second light guide plate (3b) and the optical axis (1b) of the second LED light source (1b). ') Is reflected by the prism cut (3b3a1) on the back surface (3b3) of the second light guide plate (3b) out of the light emitted from the second LED light source (1b) than when not crossed. The ratio of light can be improved.

  Furthermore, in the LED surface light emitting device (10) according to claim 3, the tip surface (3a4) of the first light guide plate (3a) is constituted by two planes (3a4a, 3a4b) orthogonal to each other. Therefore, according to the LED surface light emitting device (10) according to claim 3, the first light guide plate is more than the case where the tip surface (3a4) of the first light guide plate (3a) is constituted by a single plane. Light that passes through the tip surface (3a4) of (3a) can be reduced.

  In the LED surface light emitting device (10) according to claim 3, the tip surface (3b4) of the second light guide plate (3b) is constituted by two planes (3b4a, 3b4b) orthogonal to each other. Therefore, according to the LED surface light emitting device (10) according to claim 3, the second light guide plate is more than the case where the tip surface (3b4) of the second light guide plate (3b) is constituted by a single plane. Light that passes through the tip surface (3b4) of (3b) can be reduced.

It is the figure which showed schematically the LED surface emitting device 10 of 1st Embodiment. It is a component figure of the substantially rectangular light-guide plate 3a which comprises some LED surface light-emitting devices 10 of 1st Embodiment. It is a component diagram of the substantially rectangular light-guide plate 3b which comprises some LED surface light-emitting devices 10 of 1st Embodiment. It is a figure for demonstrating the high-speed switching mode in which the energization amount with respect to LED light source 1a, 1b of the LED surface emitting apparatus 10 of 1st Embodiment can be switched at high speed from a non-energized state. It is a figure for demonstrating the low speed switching mode in which the energization amount with respect to LED light source 1a, 1b of the LED surface emitting apparatus 10 of 1st Embodiment can be switched at low speed from a non-energized state to an energized state. It is a figure for demonstrating the low speed switching mode in which the energization amount with respect to LED light source 1a, 1b of the LED surface emitting apparatus 10 of 1st Embodiment can be switched at low speed from a non-energized state to an energized state. It is a figure for demonstrating the utilization efficiency of light L1a1, L1a2, L1b1, and L1b2 irradiated from LED light source 1a, 1b. It is a figure for demonstrating the utilization efficiency of light L1a3, L1a4, L1b3, and L1b4 from LED light source 1a, 1b. It is a figure for demonstrating the high-speed switching mode in which the energization amount with respect to LED light source 1a, 1b of the LED surface emitting apparatus 10 of 5th Embodiment can be switched at high speed from a non-energized state. It is a figure for demonstrating the low speed switching mode in which the energization amount with respect to LED light source 1a, 1b of the LED surface emitting device 10 of 5th Embodiment can be switched at low speed from a non-energized state to an energized state.

  Hereinafter, a first embodiment of the LED surface light emitting device of the present invention will be described. FIG. 1 is a diagram schematically showing an LED surface light emitting device 10 according to the first embodiment. Specifically, FIG. 1 (A) is a plan view of the LED surface light emitting device 10 of the first embodiment, and FIG. 1 (B) is a schematic view taken along lines AA and BB in FIG. 1 (A). FIG. That is, in the LED surface light emitting device 10 of the first embodiment, the vertical cross section along the line AA in FIG. 1A and the vertical cross section along the line BB in FIG. It will be the same.

  FIG. 2 is a component diagram of a substantially rectangular light guide plate 3a constituting a part of the LED surface light emitting device 10 of the first embodiment. Specifically, FIG. 2A is a plan view of the light guide plate 3a, FIG. 2B is a front view of the light guide plate 3a, FIG. 2C is a left side view of the light guide plate 3a, and FIG. The right side view of the light guide plate 3a, FIG. 2E is a bottom view of the light guide plate 3a. FIG. 3 is a component diagram of a substantially rectangular light guide plate 3b constituting a part of the LED surface light emitting device 10 of the first embodiment. Specifically, FIG. 3A is a plan view of the light guide plate 3b, FIG. 3B is a front view of the light guide plate 3b, FIG. 3C is a left side view of the light guide plate 3b, and FIG. The right side view of the light guide plate 3b, FIG. 3E is a bottom view of the light guide plate 3b.

  FIG. 4 is a diagram for explaining a high-speed switching mode in which the energization amount to the LED light sources 1a and 1b of the LED surface light emitting device 10 of the first embodiment can be switched at high speed from the non-energized state to the energized state. Specifically, FIG. 4A shows a state before the energization amount for the LED light sources 1a and 1b is switched from the non-energized state to the energized state, and FIG. 4B shows the non-energization amount for the LED light source 1a. FIG. 4C shows a state after the switch from the energized state to the energized state and before the amount of energization to the LED light source 1b is switched from the non-energized state to the energized state, and FIG. 4 (C) is for the LED light sources 1a and 1b. It is the figure which showed the state after the energization amount was switched from the non-energized state to the energized state.

  5 and 6 are diagrams for explaining a low-speed switching mode in which the energization amount to the LED light sources 1a and 1b of the LED surface light emitting device 10 of the first embodiment is switched from the non-energized state to the energized state at a low speed. Specifically, FIG. 5A shows a state before the energization amount for the LED light sources 1a and 1b is switched from the non-energized state to the energized state, and FIG. 5B shows the non-energization amount for the LED light source 1a. FIG. 5C and FIG. 6A are diagrams showing a state when the energization amount to the LED light source 1b is switched from the non-energized state to the energized state when the energized state is switched to the energized state. Fig. 6 shows a state after the energization amount for the LED light source 1a is switched from the non-energized state to the energized state, and before the energization amount for the LED light source 1b is switched from the non-energized state to the energized state. B) is a state after the energization amount for the LED light source 1a is switched from the non-energized state to the energized state, and when the energization amount for the LED light source 1b is switched from the non-energized state to the energized state. Figure showed, Fig. 6 (C) is a diagram LED light source 1a, the power supply amount for 1b is showing a state after being switched to the conductive state from the non-energized state.

  FIG. 7 is a diagram for explaining the utilization efficiency of the light L1a1, L1a2, L1b1, and L1b2 emitted from the LED light sources 1a and 1b. FIG. 8 is a diagram for explaining the utilization efficiency of the light L1a3, L1a4, L1b3, and L1b4 from the LED light sources 1a and 1b.

  In the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 1, the LED light source 1a is mounted on the substrate 2a, and the LED light source 1b is mounted on the substrate 2b. Further, for example, the LED light sources 1a and 1b and the light guide plates 3a and 3b are relatively positioned by sandwiching the substrates 2a and 2b and the light guide plates 3a and 3b by the front side plate 4a and the rear side plate 4b.

  In the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 1, two LED light sources 1 a and two LED light sources 1 b are provided, but the LED of the second embodiment is provided. In the surface light emitting device 10, any number of LED light sources 1 a other than two may be provided instead, and any number of LED light sources 1 b other than two may be provided. In the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 1, the LED light sources 1a and 1b and the light guide plates 3a and 3b are relatively positioned by the front side plate 4a and the rear side plate 4b. In the LED surface light emitting device 10 of the third embodiment, instead, the LED light sources 1a and 1b and the light guide plates 3a and 3b are relatively positioned by any positioning means different from the front plate 4a and the rear plate 4b. Is also possible. Further, in the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 1, two sets of LED light sources 1a and 1b and light guide plates 3a and 3b (that is, a set of the LED light source 1a and the light guide plate 3a, and LED light source 1b and light guide plate 3b) are provided, but in the LED surface light emitting device 10 of the fourth embodiment, an arbitrary number of LED light sources and light guide plates other than two sets are provided instead. It is also possible.

  Specifically, in the LED surface light emitting device 10 of the first embodiment, the incident surface 3a1 (see FIG. 2B and FIG. 2C) on which light from the LED light source 1a (see FIG. 1) is incident, It is comprised by the base side (left side of FIG. 2 (A), FIG.2 (B), and FIG.2 (E)) end surface of the light-guide plate 3a (refer FIG.1 and FIG.2). Furthermore, an exit surface 3a2a (see FIG. 2B) from which light guided by the light guide plate 3a exits is a front side (upper side in FIG. 1B) surface 3a2 (FIG. 2A) of the light guide plate 3a. 2 (B) and FIG. 2 (C)).

  Further, in the LED surface light emitting device 10 of the first embodiment, the back side (the lower side of FIG. 1B) surface 3a3 (FIG. 2B) and FIG. 2 (FIG. 2B) of the light guide plate 3a (see FIGS. 1 and 2). D) and FIG. 2 (E)), the prism cut 3a3a1 (see FIG. 2 (B) and FIG. 2 (E)) on the base side portion 3a3a (see FIG. 2 (B) and FIG. 2 (E)) facing the emission surface 3a2a (see FIG. 2 (B)). 2B, 2D, and 2E) are formed. Further, the light emitted from the LED light source 1a (see FIG. 1), transmitted through the incident surface 3a1 (see FIGS. 2B and 2C), and reflected by the prism cut 3a3a1 is entirely reflected on the emission surface 3a2a. The prism cut 3a3a1 is subjected to rough surface processing such as embossing.

  Furthermore, in the LED surface light emitting device 10 of the first embodiment, the front surface 3a2 of the light guide plate 3a (see FIGS. 1 and 2) (see FIGS. 2A, 2B, and 2C). A through surface 3a2b (see FIG. 2 (B)) is formed on the front end side (right side of FIGS. 2 (A), 2 (B), and 2 (E)). Further, among the back side surface 3a3 (see FIGS. 2B, 2D, and 2E) of the light guide plate 3a, the through surface 3a3b (on the tip side portion facing the through surface 3a2b of the front side surface 3a2 ( 2B and 2E) are formed.

  Further, in the LED surface light emitting device 10 of the first embodiment, as shown in FIGS. 1B and 3, the substantially rectangular light guide plate 3 b is substantially parallel to the light guide plate 3 a and the back surface of the light guide plate 3 a. It arrange | positions to the side (lower side of FIG. 1 (B)). Furthermore, as shown in FIG. 1, the LED light source 1b is arranged on the opposite side (right side in FIG. 1) of the LED light source 1a with the light guide plates 3a and 3b interposed therebetween. Further, the emission color of the LED light source 1a and the emission color of the LED light source 1b are set to be the same.

  Specifically, in the LED surface light emitting device 10 of the first embodiment, the incident surface 3b1 (see FIG. 3B and FIG. 3D) on which the light from the LED light source 1b (see FIG. 1) is incident, The light guide plate 3b (see FIG. 1B and FIG. 3) has a base side (right side in FIG. 3A, FIG. 3B, and FIG. 3E) end surface. Furthermore, the exit surface 3b2a (see FIG. 3B) from which the light guided by the light guide plate 3b exits is the front surface 3b2 of the light guide plate 3b (FIGS. 3A, 3B, and 3). C)), the through surface 3a3b (see FIG. 2 (FIG. 2)) of the back surface 3a3 (see FIG. 2 (B), FIG. 2 (D) and FIG. 2 (E)) of the light guide plate 3a (see FIG. 1 and FIG. 2). B) and the part opposite to FIG. 2 (E)). Of the back side surface 3b3 of the light guide plate 3b (see FIG. 3B, FIG. 3D and FIG. 3E), the base side portion 3b3a (FIG. 3 (FIG. 3)) facing the emission surface 3b2a of the light guide plate 3b. B) and FIG. 3E) are formed with prism cuts 3b3a1 (see FIG. 3B, FIG. 3D, and FIG. 3E).

  Furthermore, in the LED surface light-emitting device 10 of 1st Embodiment, it irradiates from LED light source 1b (refer FIG. 1), and the entrance plane 3b1 (FIG. 3 (B) of the light-guide plate 3b (refer FIG. 1 (B) and FIG. 3). ) And FIG. 3D) and the light reflected by the prism cut 3b3a1 (see FIGS. 3B, 3D, and 3E) of the light guide plate 3b is transmitted through the light guide plate 3b. Of the light guide plate 3a (see FIGS. 1 and 2) and the front surface 3a2 (see FIGS. 2A, 2B, and 2). The rough surface processing such as embossing is applied to the prism cut 3b3a1 of the light guide plate 3b so as to reach the entire through surface 3a2b (see FIG. 2B) (see C).

  In the LED surface light emitting device 10 according to the first embodiment, the LED light sources 1a and 1b (see FIG. 1) are switched from a non-energized state to an energized state at high speed, and the LED light sources 1a and 1b. There is provided a low-speed switching mode in which the energization amount for is switched from the non-energized state to the energized state at a low speed.

  Specifically, in the high-speed switching mode of the LED surface emitting device 10 of the first embodiment, as shown in FIG. 4A, the energization amount for the LED light sources 1a and 1b is switched from the non-energized state to the energized state. Before, light is not irradiated from LED light source 1a, 1b, As a result, light is not irradiated to the irradiation direction (upper side of FIG. 4 (A)) of LED surface light-emitting device 10. FIG. Next, as shown in FIG. 4B, the energization amount for only the LED light source 1a is rapidly switched from the non-energized state to the energized state, the LED light source 1a is turned on, and the energization amount for the LED light source 1a is maintained in the energized state. Is done. As a result, the light L1a irradiated from the LED light source 1a and reflected by the prism cut 3a3a1 (see FIGS. 2B, 2D, and 2E) of the light guide lens 3a is the LED surface light emitting device. 10 is irradiated in the irradiation direction (upper side in FIG. 4B). Next, as shown in FIG. 4C, the energization amount for the LED light source 1b is switched from the non-energized state to the energized state at high speed, and the LED light source 1b is turned on. As a result, the light L1b irradiated from the LED light source 1b and reflected by the prism cut 3b3a1 (see FIGS. 3B, 3D, and 3E) of the light guide lens 3b is reflected by the light guide lens 3a. 2a (see FIG. 2 (B), FIG. 2 (E)) and the front surface 3a2 (see FIG. 2 (2)). (A), see FIG. 2 (B) and FIG. 2 (C)) through the transparent surface 3a2b (see FIG. 2 (B)), the irradiation direction of the LED surface light emitting device 10 (upper side of FIG. 4 (C)) Is irradiated.

  Specifically, in the high-speed switching mode of the LED surface light emitting device 10 according to the first embodiment, as shown in FIGS. 4A and 4B, the emission surface 3a2a (FIG. 2B) of the light guide plate 3a. Energization of the LED light source 1a so that the entire state (see FIG. 4A) appears to be emitting light (see FIG. 4A) and the state appears to emit light (see FIG. 4B) simultaneously. The amount switching speed is set. Further, as shown in FIGS. 4B and 4C, the reflected light from the prism cut 3b3a1 (see FIGS. 3B, 3D, and 3E) of the light guide lens 3b. By L1b, the entire through-surface 3a2b (see FIG. 2B) of the light guide plate 3a appears to emit light from the state where it does not appear to emit light (see FIG. 4B) (see FIG. 4B). The switching speed of the energization amount for the LED light source 1b is set so as to be switched at the same time (see C).

  As a result, in the high-speed switching mode of the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 4B, after the energization amount to the LED light source 1a is switched from the non-energized state to the energized state, It is possible to form a state in which the entire emission surface 3a2a (see FIG. 2B) of the optical plate 3a appears to emit light. Further, as shown in FIG. 4C, after the energization amount to the LED light source 1b is switched from the non-energized state to the energized state, the entire through surface 3a2b (see FIG. 2B) of the light guide plate 3a emits light. It is possible to form a state that appears to be.

  On the other hand, in the low-speed switching mode of the LED surface light emitting device 10 of the first embodiment, as shown in FIGS. 5 (A), 5 (B), and 5 (C), the exit surface 3a2a (see FIG. 5) of the light guide plate 3a. 2 (B)) so as not to simultaneously switch from a state where it appears to emit light (see FIG. 5A) to a state where it appears to emit light (see FIG. 5C). The switching speed of the energization amount for the LED light source 1a is set to a low speed.

  Specifically, in the low-speed switching mode of the LED surface light emitting device 10 according to the first embodiment, as shown in FIGS. 5A and 5B, first, the light exit surface 3a2a (FIG. 2) of the light guide plate 3a is used. (See (B)), only the root side portion 3a2a1 (see FIG. 2B) is switched from a state where it does not emit light to a state where it appears to emit light, and then FIG. 5 (B). As shown in FIG. 5C, it appears that light is emitted from a state where the tip side portion 3a2a2 (see FIG. 2B) of the emission surface 3a2a of the light guide plate 3a does not emit light. The switching speed of the energization amount for the LED light source 1a is set so as to switch to the state.

  As a result, in the low-speed switching mode of the LED surface light emitting device 10 according to the first embodiment, as shown in FIG. 5B, when the energization amount to the LED light source 1a switches from the non-energized state to the energized state, the light guide plate It is possible to instantaneously form a state in which only the base side portion 3a2a1 (see FIG. 2B) of the emission surface 3a2a of 3a (see FIG. 2B) appears to emit light. Inventor's earnest research, as shown in FIG. 5 (B), the reason why only the root side portion 3a2a1 of the emission surface 3a2a of the light guide plate 3a appears to emit light can be sufficiently elucidated. However, it is considered that the illusion of the eye of the observer of the LED surface emitting device 10 is involved.

  Furthermore, in the low-speed switching mode of the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 5C, after the energization amount to the LED light source 1a is switched from the non-energized state to the energized state, the light guide plate It is possible to form a state in which the entire emission surface 3a2a of 3a (see FIG. 2B) appears to emit light. In the low-speed switching mode of the LED surface light emitting device 10 of the first embodiment, the energization amount for the LED light source 1a is thereafter maintained in the energized state.

  Further, in the low-speed switching mode of the LED surface light emitting device 10 of the first embodiment, as shown in FIGS. 6A and 6B, the emission surface 3b2a (see FIG. 3B) of the light guide plate 3b is then displayed. 2) (see FIG. 2 (B) and FIG. 2 (E)). The transparent surface 3a3b (see FIG. 2 (B) and FIG. 2 (E)) of the rear surface 3a3 (see FIG. 2 (B), FIG. 2 (D) and FIG. 2 (E)) ) And the front surface 3a2 (see FIG. 2A, FIG. 2B, and FIG. 2C) of the light guide plate 3a by the light L1b transmitted through the through surface 3a2b (see FIG. 2B). From the state where only the front end portion 3a2b2 (see FIG. 2B) of the through-surface 3a2b does not emit light, the state is changed to the state where light is emitted, and then FIG. 6B and FIG. As shown in FIG. 6C, the transparent surface 3a2b of the light guide plate 3a. The switching rate of the energization amount for the LED light source 1b is set so that the root side portion 3a2b1 (see FIG. 2B) of the base portion 3a2b1 (see FIG. 2B) does not emit light and the state appears to emit light. ing.

  As a result, in the low-speed switching mode of the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 6B, when the energization amount to the LED light source 1b switches from the non-energized state to the energized state, the light guide plate It is possible to instantaneously form a state in which only the tip side portion 3a2b2 (see FIG. 2B) of the through-surface 3a2b of 3a (see FIG. 2B) appears to emit light.

  In other words, according to the LED surface light emitting device 10 of the first embodiment, the root side portion 3a2a1 (FIG. 2B) of the emission surface 3a2a (see FIG. 2B) of the light guide plate 3a (see FIG. 2). LED light source for switching between a state that does not appear to emit light and a state that appears to emit light, and a tip side portion 3a2a2 of the exit surface 3a2a of the light guide plate 3a (see FIG. 2B) An LED light source for switching between a state that does not appear to emit light and a state that appears to emit light, and a tip side portion 3a2b2 (see FIG. 2 (2)) of the transparent surface 3a2b (see FIG. 2B) of the light guide plate 3a. B) (refer to FIG. 2 (B)), an LED light source for switching between a state that does not appear to emit light and a state that appears to emit light, and a root side portion 3a2b1 of the transparent surface 3a2b of the light guide plate 3a. ) An LED light source for switching between a state that does not appear to appear and a state that appears to emit light, without the need to independently control the non-energized state and the energized state of these LED light sources, A state in which only the base side portion 3a2a1 of the exit surface 3a2a of the light guide plate 3a appears to emit light (see FIG. 5B) and a state in which the entire exit surface 3a2a of the light guide plate 3a appears to emit light (See FIGS. 5C and 6A), a state in which only the tip side portion 3a2b2 of the through-surface 3a2b of the light guide plate 3a appears to emit light (see FIG. 6B), and the light guide plate It is possible to form a state (see FIG. 6C) in which the entire through surface 3a2b of 3a appears to emit light.

  That is, according to the LED surface light emitting device 10 of the first embodiment, the light guide plate that cannot be formed when the energization amount for the LED light source 1a (see FIG. 1) is switched from the non-energized state to the energized state at high speed. A state in which only the root side portion 3a2a1 (see FIG. 2B) of the emission surface 3a2a (see FIG. 2B) of 3a (see FIG. 1 and FIG. 2) appears to emit light (FIG. 5B) And a through surface 3a2b of the light guide plate 3a that cannot be formed when the energization amount to the LED light source 1b (see FIG. 1) is switched from the non-energized state to the energized state at high speed (see FIG. 2B). ) (See FIG. 6B) can be instantaneously formed in a state where only the tip side portion 3a2b2 (see FIG. 2B) appears to emit light.

  Further, in the LED surface light emitting device 10 of the first embodiment, the light incident surface 3a1 (FIG. 2B) and FIG. 2 of the light guide plate 3a (see FIGS. 1 and 2) are irradiated from the LED light source 1a (see FIG. 1). 2 (C)) is reflected by the prism cut 3a3a1 (see FIG. 2B, FIG. 2D and FIG. 2E) of the light guide plate 3a and reflected by the LED surface light emitting device 10. In addition to the irradiation direction (upper side in FIG. 4A), the reflected light that is irradiated from the LED light source 1a, transmitted through the incident surface 3a1 of the light guide plate 3a, and internally reflected by the light guide plate 3a The light guide plate 3a is configured to be reflected by the prism cut 3a3a1 of the light guide plate 3a and irradiated in the irradiation direction of the LED surface light emitting device 10.

  Specifically, in the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 7A, the back surface 3a3 of the light guide plate 3a and the optical axis 1a ′ of the LED light source 1a are crossed. . As a result, in the LED surface light emitting device 10 of the first embodiment, the high intensity direct light L1a1 from the LED light source 1a traveling on the optical axis 1a ′ of the LED light source 1a is reflected by the prism cut 3a3a1 and the LED surface light emitting device. 10 is irradiated in the irradiation direction (upper side in FIG. 7A). Therefore, according to the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 7B, the front side surface 3a2 and the back side surface 3a3 of the light guide plate 3a and the optical axis 1a ′ of the LED light source 1a cross each other. The direct light L1a2 from the LED light source 1a traveling on the optical axis 1a ′ of the LED light source 1a is not guided to the prism cut 3a3a1 and is guided out of the light emitted from the LED light source 1a. The ratio of the light reflected by the prism cut 3a3a1 on the back surface 3a3 of the optical plate 3a can be improved.

  Similarly, in the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 7C, the front surface 3b2 of the light guide plate 3b and the optical axis 1b 'of the LED light source 1b are crossed. As a result, in the LED surface light emitting device 10 of the first embodiment, the high-intensity light L1b1 from the LED light source 1b traveling on the optical axis 1b ′ of the LED light source 1b is reflected by the front surface 3b2 of the light guide plate 3b. Next, the light is reflected by the prism cut 3b3a1 and irradiated in the irradiation direction of the LED surface light emitting device 10 (upper side in FIG. 7C). Therefore, according to the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 7D, the front side surface 3b2 and the back side surface 3b3 of the light guide plate 3b intersect the optical axis 1b ′ of the LED light source 1b. Of the light emitted from the LED light source 1b, rather than the case where the high-intensity direct light L1b2 from the LED light source 1b traveling on the optical axis 1b ′ of the LED light source 1b does not enter the prism cut 3b3a1. The proportion of light reflected by the prism cut 3b3a1 on the back surface 3b3 of the light plate 3b can be improved.

  Furthermore, in the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 8A, the tip surface 3a4 of the light guide plate 3a (see FIG. 2) is configured by two planes 3a4a and 3a4b orthogonal to each other. Has been. As a result, in the LED surface light emitting device 10 of the first embodiment, the light L1a3 from the LED light source 1a (see FIG. 1) is reflected by the two flat surfaces 3a4a and 3a4b of the light guide plate 3a to become reflected light L1a3 ′. It is returned to the prism cut 3a3a1 (see FIG. 2B) side (the left side of FIG. 2B and FIG. 8A). Therefore, according to the LED surface light emitting device 10 of the first embodiment, the tip surface 3a4 of the light guide plate 3a is configured by a single plane as shown in FIG. 8B, and the LED light source 1a (see FIG. 1). Compared with the case where a part of the light L1a4 from the light becomes transmitted light L1a4 ′ and transmits through the front end surface 3a4 of the light guide plate 3a, light transmitted through the front end surface 3a4 of the light guide plate 3a can be reduced.

  Similarly, in the LED surface light emitting device 10 of the first embodiment, as shown in FIG. 8C, the tip surface 3b4 of the light guide plate 3b (see FIG. 3) is formed by two planes 3b4a and 3b4b orthogonal to each other. It is configured. As a result, in the LED surface light emitting device 10 of the first embodiment, the light L1b3 from the LED light source 1b (see FIG. 1) is reflected by the two flat surfaces 3b4a and 3b4b of the light guide plate 3b to become reflected light L1b3 ′. It is returned to the prism cut 3b3a1 (see FIG. 3B) side (the right side of FIG. 3B and FIG. 8C). Therefore, according to the LED surface light emitting device 10 of the first embodiment, the tip surface 3b4 of the light guide plate 3b is configured by a single plane as shown in FIG. 8D, and the LED light source 1b (see FIG. 1). As compared with the case where a part of the light L1b4 from the light becomes transmitted light L1b4 ′ and transmits through the front end surface 3b4 of the light guide plate 3b, light transmitted through the front end surface 3b4 of the light guide plate 3b can be reduced.

  Hereinafter, 5th Embodiment of the LED surface emitting device of this invention is described. In the LED surface light emitting device 10 of the first embodiment, the emission color of the LED light source 1a (see FIG. 1) and the emission color of the LED light source 1b (see FIG. 1) are set to be the same. In the LED surface light emitting device 10 of the embodiment, the light emission color of the LED light source 1a (see FIG. 1) is different from the light emission color of the LED light source 1b (see FIG. 1). Except for this point, the LED surface light-emitting device 10 of the fifth embodiment is configured in substantially the same manner as the LED surface light-emitting device 10 of the first embodiment.

  FIG. 9 is a diagram for explaining a high-speed switching mode in which the energization amount to the LED light sources 1a and 1b of the LED surface light emitting device 10 according to the fifth embodiment is switched at high speed from the non-energized state to the energized state. Specifically, FIG. 9A shows a state before the energization amount for the LED light sources 1a and 1b is switched from the non-energized state to the energized state, and FIG. 9B shows the non-energization amount for the LED light source 1a. FIG. 9C is a diagram showing a state after switching from the energized state to the energized state and before the energization amount to the LED light source 1b is switched from the non-energized state to the energized state, and FIG. 9C is for the LED light sources 1a and 1b. It is the figure which showed the state after the energization amount was switched from the non-energized state to the energized state.

  FIG. 10 is a diagram for explaining a low-speed switching mode in which the energization amount to the LED light sources 1a and 1b of the LED surface light emitting device 10 according to the fifth embodiment is switched from the non-energized state to the energized state at a low speed. Specifically, FIG. 10A shows a state after the energization amount for the LED light source 1a is switched from the non-energized state to the energized state and before the energization amount for the LED light source 1b is switched from the non-energized state to the energized state. FIGS. 10B and 10C are diagrams showing states after the energization amount to the LED light source 1a is switched from the non-energized state to the energized state, and the energization amount to the LED light source 1b is not energized. FIG. 10D is a diagram showing a state after the energization amount to the LED light sources 1a and 1b is switched from the non-energized state to the energized state. .

  In the LED surface light emitting device 10 of the fifth embodiment, the energization amount for the LED light sources 1a and 1b (see FIG. 1) is switched at high speed from the non-energized state to the energized state, and the LED light sources 1a and 1b are energized. A low speed switching mode is provided in which the amount is switched from the non-energized state to the energized state at a low speed.

  Specifically, in the high-speed switching mode of the LED surface light emitting device 10 of the fifth embodiment, as shown in FIG. 9A, the energization amount for the LED light sources 1a and 1b is switched from the non-energized state to the energized state. Before, light is not irradiated from LED light source 1a, 1b, As a result, light is not irradiated to the irradiation direction (upper side of FIG. 9 (A)) of LED surface light-emitting device 10. FIG. Next, as shown in FIG. 9B, the energization amount for only the LED light source 1a is switched from the non-energized state to the energized state at high speed, and the LED light source 1a is turned on. As a result, the light L1a of the first color irradiated from the LED light source 1a and reflected by the prism cut 3a3a1 of the light guide lens 3a (see FIG. 2B, FIG. 2D, and FIG. 2E) It irradiates in the irradiation direction (upper side of FIG. 9B) of the LED surface light emitting device 10. Next, as shown in FIG. 9C, the energization amount for the LED light source 1b is switched from the non-energized state to the energized state at high speed, and the LED light source 1b is turned on. As a result, the second light different from the first color emitted from the LED light source 1b and reflected by the prism cut 3b3a1 (see FIGS. 3B, 3D, and 3E) of the light guide lens 3b. The color light L1b ′ is transmitted through the transparent surface 3a3b (FIGS. 2B and 2E) of the back surface 3a3 (see FIGS. 2B, 2D, and 2E) of the light guide lens 3a. )) And the front surface 3a2 (see FIG. 2 (A), FIG. 2 (B) and FIG. 2 (C)) are allowed to pass through the surface 3a2b (see FIG. 2 (B)) of the LED surface light emitting device 10. Irradiation is in the irradiation direction (upper side in FIG. 9C).

  Specifically, in the high-speed switching mode of the LED surface light emitting device 10 of the fifth embodiment, as shown in FIGS. 9A and 9B, the light exit surface 3a2a (FIG. 2B) of the light guide plate 3a. The LED light source 1a is energized so that the state (see FIG. 9A) appears to be emitting light entirely (see FIG. 9A) and the state that appears to emit light (see FIG. 9B) simultaneously. The amount switching speed is set. Further, as shown in FIGS. 9B and 9C, the reflected light from the prism cut 3b3a1 (see FIGS. 3B, 3D, and 3E) of the light guide lens 3b. L1b ′ causes the entire light-transmitting surface 3a2b (see FIG. 2B) of the light guide plate 3a to appear to emit light from a state where it does not appear to emit light (see FIG. 9B) (see FIG. 9). The switching rate of the energization amount for the LED light source 1b is set so as to be switched at the same time (see (C)).

  As a result, in the high-speed switching mode of the LED surface emitting device 10 of the fifth embodiment, as shown in FIG. 9B, after the energization amount to the LED light source 1a is switched from the non-energized state to the energized state, It is possible to form a state in which the entire emission surface 3a2a (see FIG. 2B) of the optical plate 3a appears to emit light. Further, as shown in FIG. 9C, after the energization amount to the LED light source 1b is switched from the non-energized state to the energized state, the entire through surface 3a2b (see FIG. 2B) of the light guide plate 3a emits light. It is possible to form a state that appears to be.

  On the other hand, in the low-speed switching mode of the LED surface light emitting device 10 of the fifth embodiment, as shown in FIGS. 5A, 5B, and 5C, the emission surface 3a2a (see FIG. 5) of the light guide plate 3a. 2 (B)) so as not to simultaneously switch from a state where it appears to emit light (see FIG. 5A) to a state where it appears to emit light (see FIG. 5C). The switching speed of the energization amount for the LED light source 1a is set to a low speed.

  Specifically, in the low-speed switching mode of the LED surface light emitting device 10 according to the fifth embodiment, as shown in FIGS. 5A and 5B, first, the emission surface 3a2a (FIG. 2) of the light guide plate 3a is used. (See (B)), only the root side portion 3a2a1 (see FIG. 2B) is switched from a state where it does not emit light to a state where it appears to emit light, and then FIG. 5 (B). As shown in FIG. 5C, it appears that light is emitted from a state where the tip side portion 3a2a2 (see FIG. 2B) of the emission surface 3a2a of the light guide plate 3a does not emit light. The switching speed of the energization amount for the LED light source 1a is set so as to switch to the state.

  As a result, in the low-speed switching mode of the LED surface light emitting device 10 of the fifth embodiment, as shown in FIG. 5B, the light guide plate when the energization amount to the LED light source 1a switches from the non-energized state to the energized state. It is possible to instantaneously form a state in which only the base side portion 3a2a1 (see FIG. 2B) of the emission surface 3a2a of 3a (see FIG. 2B) appears to emit light.

  Furthermore, in the low-speed switching mode of the LED surface light emitting device 10 of the fifth embodiment, as shown in FIG. 5C, after the energization amount to the LED light source 1a is switched from the non-energized state to the energized state, the light guide plate It is possible to form a state in which the entire emission surface 3a2a of 3a (see FIG. 2B) appears to emit light. In the low-speed switching mode of the LED surface light emitting device 10 of the fifth embodiment, the energization amount for the LED light source 1a is thereafter maintained in the energized state.

  Further, in the low-speed switching mode of the LED surface light emitting device 10 of the fifth embodiment, the LED light source 1b is formed so that a state that does not emit light and a state that appears to emit light are formed as described later. The switching speed of the energization amount with respect to (see FIG. 1) is set.

  Specifically, in the low-speed switching mode of the LED surface light emitting device 10 according to the fifth embodiment, as shown in FIGS. 10A and 10B, the emission surface 3b2a (FIG. 3) of the light guide plate 3b is then displayed. (See (B)), and the through surface 3a3b (see FIGS. 2 (B) and 2 (B) of the back side surface 3a3 (see FIGS. 2 (B), 2 (D) and 2 (E)) of the light guide plate 3a). E)) and the front surface 3a2 (see FIG. 2A, FIG. 2B and FIG. 2C) of the second color light transmitted through the transparent surface 3a2b (see FIG. 2B). L1b ′ switches from a state where only the tip end portion 3a2b2 (see FIG. 2B) of the through-surface 3a2b of the light guide plate 3a does not emit light to a state where it appears to emit light.

  Next, in the low-speed switching mode of the LED surface light emitting device 10 of the fifth embodiment, as shown in FIGS. 10B and 10C, the emission surface 3b2a of the light guide plate 3b (see FIG. 3B). Through the transparent surface 3a3b (see FIG. 2B and FIG. 2E) of the back surface 3a3 of the light guide plate 3a (see FIG. 2B, FIG. 2D and FIG. 2E) and The light of the second color transmitted through the surface 3a2b (see FIG. 2B) of the front surface 3a2 (see FIGS. 2A, 2B, and 2C) and the light guide plate 3a The prism cut 3a3a1 (see FIGS. 2B, 2D, and 2E) leaks out of the prism cut 3b3a1 (FIGS. 3B, 3D, and 3D) of the light guide plate 3b. 3 (E)) and is emitted from the exit surface 3b2a of the light guide plate 3b to guide the light. The root of the through surface 3a2b of the front surface 3a2 of the light guide plate 3a by the mixed light L1b "with the first color light transmitted through the through surface 3a3b of the back surface 3a3 of 3a and the through surface 3a2b of the front surface 3a2 The state in which the side portion 3a2b1 (see FIG. 2B) does not seem to emit light is switched to the state in which it appears to emit light in the third color in which the first color and the second color are mixed.

  Next, in the low-speed switching mode of the LED surface light emitting device 10 of the fifth embodiment, as shown in FIGS. 10 (C) and 10 (D), the exit surface 3b2a of the light guide plate 3b (see FIG. 3 (B)). Through the transparent surface 3a3b (see FIG. 2B and FIG. 2E) of the back surface 3a3 of the light guide plate 3a (see FIG. 2B, FIG. 2D and FIG. 2E) and The light is guided by the light L1b ′ of the second color transmitted through the through surface 3a2b (see FIG. 2B) of the front surface 3a2 (see FIGS. 2A, 2B, and 2C). The entire through surface 3a2b of the front surface 3a2 of the optical plate 3a appears to emit light in the second color.

  In other words, according to the LED surface light emitting device 10 of the fifth embodiment, the energization amount for the LED light source 1b (see FIG. 10) is maintained while the energization amount for the LED light source 1a (see FIG. 10) is maintained in the energized state. By switching from the non-energized state to the energized state at a low speed, the entire emission surface 3a2a (see FIG. 2B) of the light guide plate 3a emits light in the first color, and the front surface 3a2 of the light guide plate 3a A first light emission state (see FIG. 10 (B)) in which only the tip side portion 3a2b2 (see FIG. 2) of the transparent surface 3a2b (see FIG. 2 (B)) appears to emit light in the second color; The entire light exit surface 3a2a of the light guide plate 3a appears to emit light in the first color, and the tip side portion 3a2b2 of the through surface 3a2b of the front surface 3a2 of the light guide plate 3a emits light in the second color. The light guide plate a second light emission state (see FIG. 10C) in which the root side portion 3a2b1 (see FIG. 2B) of the through-surface 3a2b of the front surface 3a2 of a appears to emit light in the third color; The entire light exit surface 3a2a of the light guide plate 3a appears to emit light in the first color, and the entire through surface 3a2b of the front surface 3a2 of the light guide plate 3a appears to emit light in the second color. Three light-emitting states (see FIG. 10D) can be formed.

  That is, according to the LED surface light emitting device 10 of the fifth embodiment, only by changing the energization amount to the LED light source 1b (see FIG. 10), the first light emission state (see FIG. 10B), the second Three light emission states can be formed: a light emission state (see FIG. 10C) and a third light emission state (see FIG. 10D).

  That is, according to the LED surface light emitting device 10 of the fifth embodiment, as shown in FIG. 9, the LED light source 1b cannot be formed when the energization amount to the LED light source 1b is switched from the non-energized state to the energized state at high speed. One light emission state (see FIG. 10B) and the second light emission state (see FIG. 10C) can be instantaneously formed. In the diligent research of the present inventors, the reason why the first light emitting state as shown in FIG. 10B and the second light emitting state as shown in FIG. It was concluded that the optical illusion of 10 observers was involved. Specifically, it leaks from the prism cut 3a3a1 (see FIGS. 2B, 2D, and 2E) of the light guide plate 3a, and the prism cut 3b3a1 (FIG. 3B) of the light guide plate 3b. 3D and FIG. 3E), the light is emitted from the emission surface 3b2a of the light guide plate 3b, and is transmitted through the through surface 3a3b of the back surface 3a3 of the light guide plate 3a and the through surface 3a2b of the front surface 3a2. The light of the first color to be shown is irradiated from the LED light source 1a and reflected by the prism cut 3a3a1 (see FIGS. 2B, 2D, and 2E) of the light guide lens 3a, and the LED surface. Since it is weaker (darker) than the light L1a of the first color irradiated in the irradiation direction of the light emitting device 10 (the upper side of FIGS. 10B and 10C), the first light emitting state (see FIG. 10B) ) And the second emission state ( 10 (C) see) are considered to have an illusion that is instantaneously formed occurs observer's eyes the LED surface 10.

  In the sixth embodiment, the above-described first to fifth embodiments can be appropriately combined.

  The LED surface light emitting device of the present invention can be applied to a lighting device such as a lighting device for effects.

1a, 1b LED light sources 3a, 3b Light guide plates 3a1, 3b1 Incident surfaces 3a2, 3b2 Front side surfaces 3a2a, 3b2a Outgoing surfaces 3a2a1, 3a2a2 Portions 3a3, 3b3 Back side surfaces 3a3a, 3b3a Portions 3a3a1, 3b3a1 Prism cut 10 LED light emitting device

Claims (2)

A rectangular first light guide plate, a rectangular second light guide plate disposed on the back side of the first light guide plate and substantially parallel to the first light guide plate, a first LED light source, In a surface light emitting device having a second LED light source,
The first light guide plate includes a first incident surface, a first emission surface, a first surface through surface, a first prism surface, and a first back surface through surface,
The second light guide plate has a second incident surface, a second emission surface, and a second prism surface,
The first LED light source is provided at a position facing the first incident surface,
The second LED light source is provided at a position facing the second incident surface,
The first LED light source and the second LED light source are arranged to face each other across the first light guide plate and the second light guide plate,
The first emission surface is formed on at least a part of a front surface of the first light guide plate,
The first surface through surface is formed on a surface of the front side surface of the first light guide plate where the first emission surface is not provided,
The first back surface through surface is formed at a position facing the first surface through surface of the back side surface of the first light guide plate,
The first prism surface is formed at a position facing the first emission surface in the back side surface of the first light guide plate,
The second emission surface is formed at a position facing the first back surface through surface of the front surface of the second light guide plate.
The second prism surface is formed at a position facing the second emission surface in the back side surface of the second light guide plate,
Of the light emitted from the first LED light source and entering the first light guide plate at the first incident surface, the light reflected by the first prism surface is transmitted to the outside from the first emission surface. The light that has exited and leaked from the first prism surface is directed toward the second prism surface of the second light guide plate and reflected by the second prism surface to the second exit surface, and finally. By being emitted from the second emission surface, the first light guide plate is transmitted to the outside through the first back surface passing surface and the first surface passing surface,
The light emitted from the second LED light source and entering the second light guide plate at the second incident surface is reflected by the second prism surface to the second emission surface, and finally the second emission. By being emitted from the surface, the first light guide plate passes through the first back surface through surface and the first surface through surface and is emitted to the outside.
Non-energized state by said a first mode to switch to the conduction state from a non-energized state the energization amount at the first switching speed for the first 1LED light source, the slower second switching speed than the energization amount of the first switching speed for the first 1LED light source A second mode for switching from the non-energized state to the energized state at the second switching speed while maintaining the energized amount for the first LED light source in the energized state; Mode, and
The LED surface light-emitting device , wherein the first LED light source and the second LED light source emit different emission colors .
  Crossing one of the front side surface and the back side surface of the first light guide plate and the optical axis of the first LED light source;
  Crossing one of the front side surface and the back side surface of the second light guide plate and the optical axis of the second LED light source;
  The tip surface located on the opposite side of the first incident surface of the first light guide plate is constituted by two planes orthogonal to each other,
  2. The LED surface light emitting device according to claim 1, wherein a front end surface of the second light guide plate located on the opposite side of the second incident surface is constituted by two planes orthogonal to each other.

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