Patent Publication Number: US-10783739-B2

Title: Push-button for game machine

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on Japanese Patent Application No. 2017-218288 filed with the Japan Patent Office on Nov. 13, 2017, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The present invention relates to a push-button for a game machine to cause a side surface of the push button to emit light. 
     BACKGROUND 
     In game facilities like casinos, game machines such as slot machines are installed. In the game facilities, not only slot machines manufactured by a single game machine manufacturer but also slot machines manufactured by various game machine manufacturers are installed. A player selects a slot machine meeting his or her preference among the slot machines manufactured by various game machine manufacturers and plays a game. Hence in the game facilities, a slot machine popular with players is installed to ensure superiority over other competing game facilities. For example, as disclosed in Japanese Unexamined Patent Application Publication No. 2007-317380 (published on Dec. 6, 2007), a push-button mounted on a slot machine has been caused to emit light so that the slot machine appeals to the player. In the technique disclosed in Japanese Unexamined Patent Application Publication No. 2007-317380, light from a light emitting element is applied to an operation surface through a diffusion sheet to cause the operation surface to emit light. 
     However, in the technique disclosed in Japanese Unexamined Patent Application Publication No. 2007-317380, since natural diffusion by the light emitting element is mainly performed and, furthermore, the diffusion sheet as a diffusion assisting member is used, the distance from the light emitting element to the operation surface becomes long. This has caused a problem of increasing the thickness of the push-button. 
     SUMMARY 
     An object of one aspect of the present invention is to achieve provision of a push-button for a game machine capable of causing a side surface of the push button to emit light, without increasing a thickness of the push-button. 
     In order to solve the above problem, a push-button for a game machine according to an aspect of the present disclosure is a push-button for a game machine which is mounted on the game machine and includes: an operation key configured to accept a press; a side surface portion having translucency and provided in a direction perpendicular to a pressing direction of the operation key as viewed from the operation key; a light source configured to apply light in a direction parallel to the pressing direction; and a light guiding portion configured to guide light applied from the light source. The light guiding portion includes a first reflective structure configured to reflect at least a part of the light applied from the light source, and a second reflective structure configured to reflect at least a part of the light reflected by the first reflective structure toward the side surface portion. 
     With the above configuration, the light guiding portion guides light in the direction parallel to the pressing direction to cause the side surface portion to emit light. It is thereby possible to cause the side surface portion to emit light without increasing the thickness of the push-button for the game machine in the pressing direction. Further, since the light guiding distance from the light source to the side surface portion can be made long, the light can be applied to the side surface portion, having a large length perpendicular to the pressing direction, over a wide range. 
     In a push-button for a game machine according to an aspect of the present disclosure, the first reflective structure may reflect at least a part of the light applied from the light source in a direction parallel to the side surface portion and perpendicular to the pressing direction, and the second reflective structure may be disposed in a direction parallel to the side surface portion and perpendicular to the pressing direction with respect to the first reflective structure. 
     With the above configuration, it is possible to spread the light emitted from the light source in the direction parallel to the side surface portion and then to reflect the light toward the side surface portion. As a result, the light can be applied to the side surface portion, having a large length perpendicular to the pressing direction, over a wide range. 
     In a push-button for a game machine according to an aspect of the present disclosure, it is preferable that in a light irradiation region to which the light is applied from the light source, the first reflective structure be provided in a partial region being smaller than the light irradiation region and including an optical axis center of the light emitted from the light source. 
     With the above configuration, among the light emitted from the light source, light having not been applied to the first reflective structure is applied to the side surface portion in the vicinity of the light source. As a result, a part of the light emitted from the light source is reflected by the second reflective structure and emitted from the side surface portion to an outside, and the other light emitted from the light source is applied to the side surface portion in the vicinity of the light source. It is thereby possible to cause the side surface portion to emit light uniformly. 
     In a push-button for a game machine according to an aspect of the present disclosure, it is preferable that the second reflective structure include a first reflective surface and a second reflective surface, and the first reflective surface and the second reflective surface reflect the light reflected by the first reflective structure in an identical direction, and have mutually different distances from the first reflective structure. 
     With the above configuration, the wide range of the side surface portion can be caused to emit light in the direction perpendicular to the pressing direction. 
     In a game machine push-button according to an aspect of the present disclosure, a plurality of the first reflective structures may be provided, and only one second reflective structure may be provided between two of the first reflective structures adjacent to each other. 
     With the above configuration, it is possible to make the light guiding portion structurally simple, as compared to the case of providing a plurality of reflective structures for reflecting the light reflected by the first reflective structure toward the side surface portion. 
     In a push-button for a game machine according to an aspect of the present disclosure, it is preferable that the side surface portion diffuse the light reflected by the second reflective structure and apply the light to an outside. 
     With the above configuration, the light reflected by the second reflective structure is diffused and applied to the outside. It is thereby possible to cause the side surface portion to emit light more uniformly. 
     According to an aspect of the present invention, it is possible to achieve provision of a push-button for a game machine capable of causing a side surface of the push button to emit light, without increasing a thickness of the push-button. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of a slot machine mounted with a push-button according to a first embodiment of the present invention, and  FIG. 1B  is a top view of the slot machine; 
         FIG. 2  is a perspective view illustrating an appearance of the push-button; 
         FIG. 3  is a top view of the push-button; 
         FIG. 4  is a side view of the push-button; 
         FIG. 5  is an exploded perspective view of the push-button; 
         FIG. 6  is a top view of a base included in the push-button; 
         FIG. 7  is a sectional view taken along line A-A illustrated in  FIG. 6 ; 
         FIG. 8  is a plan view illustrating a configuration of a second reflective structure included in the base; 
         FIG. 9  is a plan view of a key top included in the push-button as viewed from below; 
         FIG. 10  is an enlarged view of region B in  FIG. 6 ; 
         FIG. 11  is a sectional view taken along line A-A illustrated in  FIG. 3 ; 
         FIG. 12  is a top view of a base included in a push-button as a modified example of the push-button; 
         FIG. 13  is an enlarged view of region C in  FIG. 12 ; and 
         FIG. 14  is a plan view illustrating a configuration of a second reflective structure included in the push-button as the modified example. 
     
    
    
     DETAILED DESCRIPTION 
     First Embodiment 
     Hereinafter, an embodiment according to an aspect of the present disclosure (hereinafter also referred to as “the embodiment”) will be described with reference to the drawings. In the embodiment, a push-button  1  as an aspect of a push-button for a game machine in the present disclosure will be described. The push-button  1  is the push-button for the game machine which is mounted on a game machine such as a slot machine. 
     § 1 Application Example 
     First, with reference to  FIGS. 1A, 1B, 7, and 10 , an example of a scene in which the push-button  1  is applied will be described.  FIG. 1A  is a perspective view of a slot machine S mounted with the push-button  1 , and  FIG. 1B  is a top view of the slot machine S. As illustrated in  FIGS. 1A and 1B , in the slot machine S, the push-button  1  is disposed at a position where the push-button  1  is operated by a player. 
     The push-button  1  includes a light-emitting diode (LED)  32  (light source), a base  2 , and a bezel  5 . The base  2  includes a first reflective structure  26  and a second reflective structure  27 . As illustrated in  FIGS. 7 and 10 , in the push-button  1 , the first reflective structure  26  in the base  2  reflects light applied from the LED  32 , and thereafter, the second reflective structure  27  reflects the light toward the bezel  5 . As a result, the bezel  5  having translucency is caused to emit light. That is, light is guided in a direction perpendicular to a vertical direction in the base  2  to cause the bezel  5  to emit light. It is thereby possible to cause the bezel  5  to emit light without increasing the vertical thickness of the push-button  1 . In addition, since the light guiding distance of the light from the LED  32  to the bezel  5  can be made long, the light can be applied to the bezel  5 , having a large length perpendicular to the vertical direction, over a wide range. 
     § 2 Configuration Example 
     The configuration of the push-button  1  of an aspect of the present disclosure will be described in detail with reference to the drawings.  FIG. 2  is a perspective view illustrating the appearance of the push-button  1 .  FIG. 3  is a top view of the push-button  1 .  FIG. 4  is a side view of the push-button  1 .  FIG. 5  is an exploded perspective view of the push-button  1 . In the following, for convenience of description, a +X direction in  FIG. 3  may be described as a right direction, a −X direction as a left direction, a +Y direction as a back direction, a −Y direction as a front direction, a +Z direction as an up direction, a −Z direction as a down direction. 
     As illustrated in  FIG. 3 , the push-button  1  has a substantially triangular shape in a plan view from above. However, the push-button of the present invention is not limited to the configuration to have a substantially triangular shape in a plan view from above, and may have a polygonal shape such as a quadrangle or a circular shape in a plan view from above. As illustrated in  FIGS. 2 to 5 , the push-button  1  includes the base  2 , a printed circuit board (PCB, substrate)  3 , a key top  4  (operation key), the bezel  5  (side surface portion), a back cover  6 , and a waterproof packing  7 . 
       FIG. 6  is a top view of the base  2 . The base  2  is a member for supporting the key top  4 , the bezel  5 , and the waterproof packing  7 . As illustrated in  FIGS. 5 and 6 , the base  2  has an inner wall  20  and an outer periphery  21  (light guiding portion). 
     The inner wall  20  is a wall provided inside the base  2  and extending vertically from the outer periphery  21 . The inner wall  20  is formed in a substantially triangular shape as viewed from above. On the inner side of the inner wall  20 , a central portion  41  of the key top  4 , described later, is housed movably in the vertical direction (see  FIG. 11 ). The inner wall  20  has a light shielding property. 
     The outer periphery  21  surrounds the outer periphery of the inner wall  20  and has a substantially triangular shape as viewed from above. The outer periphery  21  has translucency. As illustrated in  FIG. 6 , on an upper surface  22  of the outer periphery  21 , two rubber receivers  23 , and three spring receivers  24  are formed. 
     The rubber receiver  23  is provided at a position facing a rubber receiver  43  of the key top  4 , described later, on the upper surface  22  and has a circular flat surface. The spring receiver  24  is a columnar member projecting upward from the upper surface  22 . In the spring receiver  24 , a spring  71  is inserted. 
     In addition, as illustrated in  FIG. 6 , the outer periphery  21  is formed with an opening  25  opened in the vertical direction in a region corresponding to a place where a sensor  31  of the PCB  3 , described later, is formed. 
     Further, on the upper surface  22  of the outer periphery  21 , the first reflective structure  26  and the second reflective structure  27  are formed. 
       FIG. 7  is a sectional view taken along line A-A illustrated in  FIG. 6 . As illustrated in  FIGS. 6 and 7 , the first reflective structure  26  is a V-shaped groove formed so as to project downward from the upper surface  22  of the outer periphery  21 . As illustrated in  FIG. 6 , the first reflective structure  26  is formed from the inside to the outside of the base  2 . The first reflective structure  26  is formed above a region where the LED  32 , described later, is installed in the PCB  3 . As illustrated in  FIG. 7 , the first reflective structure  26  has two reflective surfaces  26   a . In the push-button  1  in the embodiment, ten first reflective structures  26  are formed on the outer periphery  21 . 
     As illustrated in  FIG. 6 , the second reflective structure  27  is formed by recessing the upper surface  22  of the outer periphery  21  downward, and has a mountain shape projecting from the inside toward the outside of the base  2 . 
       FIG. 8  is a plan view illustrating the configuration of the second reflective structure  27 . The second reflective structure  27  has a symmetrical shape with respect to a plane parallel to the vertical direction from the inside to the outside of the base  2 . As illustrated in  FIG. 8 , on each of the left and right sides from the inside to the outside, the second reflective structure  27  has a first surface  27   a  (first reflective surface), a second surface  27   b , and a third surface  27   c  (second reflective surface) which are planes parallel to the vertical direction. The first surface  27   a  and the third surface  27   c  are formed obliquely at the same angle with respect to a plane extending from the inside to the outside of the base  2 . The second surface  27   b  is formed perpendicularly to the plane extending from the inside to the outside of the base  2 . The second surface  27   b  connects the first surface  27   a  and the third surface  27   c.    
     As illustrated in  FIG. 5 , the PCB  3  has a substantially triangular shape as viewed from above. The PCB  3  is disposed so as to be in contact with the lower surface of the base  2 . The PCB  3  is a substrate on the upper surface of which three sensors  31  and twelve light emitting diodes (LEDs)  32  as light sources are mounted. The sensor  31  and the LED  32  are electrically connected to the PCB  3 . The PCB  3 , together with the back cover  6 , is fixed to the lower surface of the base  2  by using screws  72 . 
     The sensor  31  is a sensor for detecting that the key top  4  has been pressed by the player, and in the embodiment, the sensor  31  is a photosensor. The three sensors  31  are provided on the top of the PCB  3 . The sensor  31  is substantially U-shaped having an opening opened upward. A method for detecting a press of the key top  4  by the sensor  31  will be described later. The result detected by the sensor  31  is output to a controller (not illustrated) of the push-button  1  through the PCB  3 . 
     The LED  32  is a light emitting unit for causing the bezel  5 , described later, to emit light. The twelve LEDs  32  are provided on the top of the PCB  3  at substantially the same intervals. As illustrated in  FIG. 7 , the LED  32  applies light upward. A detail of the light emission of the bezel  5  by using the LED  32  will be described later. 
     The key top  4  is an operation key for accepting an operation (press) by a player. As illustrated in  FIG. 5 , the key top  4  includes the central portion  41  and a side surface portion  42 . 
     The shape of the central portion  41  in a plan view from above is substantially the same as that of a region surrounded by the inner wall  20  of the base  2 . The central portion  41  has translucency. In the push-button  1 , with the central portion  41  having translucency, when a liquid crystal display (LCD) (not illustrated) is disposed below the push-button  1 , the player can view an image of the LCD. Note that the LCD displays display information such as characters and symbols in a region facing the key top  4 . 
     The side surface portion  42  is provided around the central portion  41  and has a substantially L-shaped cross section taken along a cross section perpendicular to the horizontal direction (see  FIG. 11 ). A recess, into which the inner wall  20  of the base  2  is inserted, is formed between the central portion  41  and the side surface portion  42 . The side surface portion  42  is separated from the base  2  by a predetermined distance (at least a distance by which the key top  4  is pushed from the player) in a state where the key top  4  is not pressed by the player. 
       FIG. 9  is a plan view of the key top  4  as viewed from below. As illustrated in  FIG. 9 , two rubber receivers  43 , three spring receivers  44 , and three plate attachment portions  45  are provided on the lower surface of the side surface portion  42 . 
     The rubber receiver  43  is provided at a position facing the rubber receiver  23  of the base  2 , and has a circular flat surface. As illustrated in  FIG. 5 , a rubber  73  is inserted between the rubber receiver  43  and the rubber receiver  23  of the base  2 . 
     The spring receiver  44  is a columnar member projecting downward from the lower surface of the side surface portion  42 . The spring  71  is inserted between the spring receiver  44  and the spring receiver  24  of the base  2 . With the above configuration, the spring  71  applies an urging force to the key top  4  upward, and when the player is not pressing the key top  4 , the key top  4  is held in a pushed-up state. 
     The plate attachment portion  45  is a member to which a plate  75  is attached, the plate  75  detecting that the key top  4  has been pressed by the sensor  31 . The plate  75  is provided with a base portion  75   a  that is attached to the plate attachment portion  45  and a bent portion  75   b  formed by bending the end of the base portion  75   a.    
     Here, a description will be given of an operation in the push-button  1  at the time when the player presses the key top  4 . When the player presses the key top  4 , first, the key top  4  moves downward against the urging force of the spring  71 . As a result, the plate  75  moves downward, and the bent portion  75   b  of the plate  75  moves between the openings of the sensor  31 . Then, the sensor  31  detects the bent portion  75   b , thereby detecting that the player has pressed the key top  4 . In addition, as described above, the rubber  73  is inserted between the rubber receiver  43  of the key top  4  and the rubber receiver  23  of the base  2 , and hence a click feeling can be given to the player when the player presses the key top  4 . 
     The bezel  5  has translucency and is a cover member for covering (protecting) a part of the upper surface and the side surface of the push-button  1 . The bezel  5  is provided in a region around the key top  4  in a direction parallel to the vertical direction. The bezel  5  has an opening at the center. Hence the key top  4  projects to the upper side of the bezel  5  through the opening, and the key top  4  is loosely fitted in a pressable manner. Further, the bezel  5  is a diffusing material and diffuses the applied light. 
     The waterproof packing  7  is installed outside the bezel  5  and is a member for preventing water from entering the PCB  3 . 
     § 3 Operation Example 
     Next, the light guiding path of the light emitted from the LED  32  will be described with reference to  FIGS. 7, 10, and 11 .  FIG. 10  is an enlarged view of region B in  FIG. 6 .  FIG. 11  is a sectional view taken along line A-A illustrated in  FIG. 3 .  FIG. 11  is a sectional view taken along a plane passing through an optical axis center of the LED  32 . 
     First, as illustrated in  FIG. 7 , the LED  32  applies light upward. More specifically, with the vertical direction as the optical axis, the LED  32  applies light at an irradiation angle of 60° (120° in total) on both sides of the optical axis in a direction parallel to the bezel  5 . The light applied from the LED  32  is incident on the outer periphery  21  of the base  2 . 
     A part of the light incident on the outer periphery  21  of the base  2  is applied to the first reflective structure  26  provided above the LED  32 . Note that the first reflective structure  26  is formed in a region including the optical axis center of the LED  32 . As illustrated in  FIGS. 7 and 11 , the light applied to the first reflective structure  26  is reflected by the reflective surface  26   a  of the first reflective structure  26  in a direction parallel to the bezel  5  and perpendicular to the vertical direction (the pressing direction of the key top  4 ) (a horizontal direction in  FIG. 7 ). In other words, the light applied to the first reflective structure  26  is reflected at an angle different from an angle at which the light is applied to the first reflective structure  26 . Note that the direction of the light reflected by the reflective surface  26   a  of the first reflective structure  26  does not have to be completely parallel to the bezel  5  and perpendicular to the vertical direction, and some angular deviation is permitted. 
     Next, as illustrated in  FIG. 10 , the light reflected by the reflective surface  26   a  of the first reflective structure  26  is guided inside the outer periphery  21  and reaches the adjacent second reflective structure  27 . The light reached the second reflective structure  27  is reflected toward the outside (i.e., toward the bezel  5 ) by each of the first surface  27   a  and the third surface  27   c  of the second reflective structure  27 . The light reflected by each of the first surface  27   a  and the third surface  27   c  is transmitted through the bezel  5  and is emitted to the outside. Hence it is possible to cause the bezel  5  to emit light. In a region where the second reflective structure  27  and the bezel  5  are in contact (a region surrounded by a dotted line in  FIG. 8 ), the bezel  5  is caused to emit light not by the light reflection by the second reflective structure  27  but by the light transmitted through the second reflective structure  27 . 
     As described above, in the push-button  1 , the light applied from the LED  32  is reflected by the first reflective structure  26  and the second reflective structure  27  formed on the outer periphery  21  of the base  2  to cause the bezel  5  to emit light. That is, the light is guided in the direction perpendicular to the vertical direction and parallel to the bezel  5  to cause the bezel  5  to emit light. It is thereby possible to cause the bezel  5  to emit light without increasing the vertical thickness of the push-button  1 . In addition, since the light guiding distance of the light from the LED  32  to the bezel  5  can be made long, the light can be applied to the bezel  5 , having a large length perpendicular to the vertical direction, over a wide range. 
     In the push-button  1 , the first reflective structure  26  reflects a part of the light applied from the LED  32  in the direction parallel to the bezel  5  and perpendicular to the vertical direction, and the second reflective structure  27  is disposed in a direction parallel to the bezel  5  and perpendicular to the vertical direction with respect to the first reflective structure  26 . As a result, a part of the light emitted from the LED  32  can be spread in a direction parallel to the bezel  5 , and can thereafter be reflected toward the bezel  5 . As a result, it is possible to apply the light to the bezel  5 , having a large length perpendicular to the vertical direction, over a wide range. The “parallel direction” or the “vertical direction” described above need not be perfectly parallel or perpendicular, and some deviation is permitted. 
     Further, in the push-button  1 , in a region to which the light is applied from the LED  32  (hereinafter referred to as a light irradiation region), the first reflective structure  26  is formed in a partial region being smaller than the light irradiation region and including the optical axis center of the light emitted from the LED  32 . Thus, among the light emitted from the LED  32 , light having not been applied to the first reflective structure  26  is applied to the upper surface  22  of the outer periphery  21  of the base  2 , and is applied from the bezel  5  to the outside in the vicinity of the LED  32 . As a result, a part of the light emitted from the LED  32  is reflected by the second reflective structure  27  and emitted from the bezel  5  to the outside (i.e., emitted from a position distant from the LED  32  to the outside), and the other light emitted from the LED  32  is emitted to the outside in the vicinity of the LED  32 . That is, it is possible to cause the bezel  5  to emit light uniformly. 
     Further, as described above, the second reflective structure  27  includes the first surface  27   a  and the third surface  27   c , and the distance from the first reflective structure  26  to the first surface  27   a  is smaller than the distance therefrom to the third surface  27   c . As a result, the light reflected by the first surface  27   a  is reflected to the light toward the bezel  5  in a region close to the first reflective structure  26  as compared to the light reflected by the third surface  27   c . That is, the light reflected by the first surface  27   a  and the light reflected by the third surface  27   c  enable light emission over a wider range of the bezel  5 . 
     Further, one second reflective structure  27  is provided between the first reflective structures  26  adjacent to each other. It is thus possible to make the base  2  structurally simple as compared to the case of providing a plurality of reflective structures for reflecting the light reflected by the first reflective structure  26  toward the bezel  5 . 
     Further, as described above, the bezel  5  is made of a diffusing material, diffuses the light reflected by the second reflective structure  27  and applies the light to the outside. Hence the bezel  5  can be caused to emit light more uniformly. 
     In addition, the inner wall  20  of the base  2  has a light shielding property. This prevents leakage of the light applied from the LED  32  to the inside of the base  2  (i.e., in the direction to the key top  4 ). 
     In the aspect of the embodiment, the LED  32  applies light upward, but the push-button for the game machine of the present invention is not limited thereto. For example, in some aspect of the embodiment, separately from the PCB  3  on which the sensor  31  is placed, a PCB mounted with the LED  32  may be provided and installed on the top of the base  2 , and the LED  32  may apply light downward. However, in this case, it is necessary to provide the first reflective structure and the second reflective structure on the lower surface of the outer periphery  21 . 
     § 4 Modified Example 
     Next, a push-button  1 A as a modified example of the push-button  1  will be described. For convenience of description, members having the same functions as the members described in the above embodiment are denoted by the same reference numerals, and the description thereof will not be repeated. 
       FIG. 12  is a top view of a base  2 A included in the push-button  1 A. FIG.  13  is an enlarged view of region C in  FIG. 12 .  FIG. 14  is a plan view illustrating a configuration of a second reflective structure  28 . 
     As illustrated in  FIG. 12 , the push-button  1 A includes the base  2 A instead of the base  2  in the first embodiment. The base  2 A includes the second reflective structure  28  in place of the second reflective structure  27  in the first embodiment. 
     As illustrated in  FIGS. 13 and 14 , the second reflective structure  28  is formed by recessing the upper surface  22  of the outer periphery  21  downward. The second reflective structure  28  is made up of five reflective structures  28   a ,  28   b ,  28   c ,  28   d ,  28   e , each having a substantially triangular shape and projecting from the inside toward the outside of the base  2 . 
     The reflective structure  28   c  is formed to be larger than the reflective structures  28   a ,  28   b ,  28   d ,  28   e , and the reflective structures  28   b ,  28   d  are formed to be larger than the reflective structures  28   a ,  28   e.    
     The reflective structures  28   a ,  28   b ,  28   c  respectively have reflective surfaces  28   aa ,  28   ba ,  28   ca  for each reflecting the light guided from the right side toward the outside (i.e., toward the bezel  5 ) in  FIG. 14 . Further, the reflective structures  28   c ,  28   d ,  28   e  respectively have reflective surfaces  28   ca ,  28   da ,  28   ea  for each reflecting the light guided from the left side toward the outside in  FIG. 14 . 
     With the above configuration, in the push-button  1 A, the light applied from the LED  32  and reflected by the first reflective structure  26  is reflected by the reflective structures  28   a ,  28   b ,  28   c ,  28   d ,  28   e  of the second reflective structure  28  toward the outside (i.e., toward the bezel  5 ). Hence it is possible to cause the bezel  5  to emit light. 
     Moreover, the reflective surfaces  28   aa ,  28   ba ,  28   ca  have mutually different distances from the first reflective structure  26 . As a result, it is possible to apply the light to the bezel  5 , having a large length perpendicular to the vertical direction, over a wide range. That is, it is possible to cause the bezel  5  to emit light uniformly. 
     The present invention is not limited to each of the embodiments described above, but can be subjected to a variety of changes in the scope shown in the claims. An embodiment obtained by appropriately combining technical units disclosed respectively in different embodiments is also included in a technical scope of the present invention.