Patent Publication Number: US-2022214026-A1

Title: Self-illuminating manipulation element

Description:
TECHNICAL FIELD 
     The present invention relates to a self-illuminating control element. 
     BACKGROUND ART 
     A self-illuminating control element, whose operation surface is illuminated, is used as a control element of electronic devices. Such a self-illuminating control element is used as, as well as a control button of electronic devices, a musical pad of an electronic musical instrument and the like. 
     The self-illuminating control element often includes a control element body made of a light-transmissive material, a surface of the control element body being coated with a light-blocking paint, a part of which is removed to form a picture pattern (see, for instance, Patent Literatures 1 and 2). 
     In Patent Literature 1, the self-illuminating control element in a form of a button, which is made of a light-transmissive material, passes light from a light source provided at a backside through to a top surface (i.e. to an operation surface) for illumination. The surface of the button is provided all over with a painted light-shielding film, which is partially removed in a predetermined shape to allow the light to penetrate through the part where the light-shielding film is removed, thereby providing a luminous image of a predetermined figure and/or character (see paragraph [0011]). At this time, the color of the transmitted light is determined by a light-transmissive white paint and/or green print layer coated prior to forming the light-shielding film (see paragraph [0012]). 
     In Patent Literature 2, an operation surface of the self-illuminating control element, which is to be pushed by a user, is in a form of a center button (push button) and configured to be illuminated. The operation surface is painted white to become entirely luminous or painted black over a white paint to become partially luminous at a part of a mark (e.g. character and icon) where the black paint is removed by laser or the like (paragraph [0012]). 
     As described above, the button itself is made of a light-transmissive material (e.g. resin) in both of Patent Literatures 1 and 2. This is because a predetermined level of strength and elasticity are required in order to accept the pushing operations and the like. Further, the light source is provided independent of the button body because the control element, which is pushed to be moved, is not adapted to have a built-in light source. 
     CITATION LIST 
     Patent Literature(s) 
     Patent Literature 1: International Publication WO 2014/106897 
     Patent Literature 2: JP 2013-134359 A 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     As described above, the typical self-illuminating control element has a light-transmissive body whose surface is provided with a light-shielding film formed by coating or the like, which is partially removed so that the surface becomes luminous in a predetermined shape (e.g. character and icon). 
     Accordingly, a large amount of the light transmitted from an external light source through the light-transmissive body to the operation surface is sometimes blocked, failing to provide light quantity sufficient for the light emission at the operation surface. 
     An object of the invention is to provide a self-illuminating control element capable of increasing light quantity transmitted through the operation surface. 
     Means for Solving the Problems 
     A self-illuminating control element includes: a light-transmissive control element body including: an operation surface in which an illuminating portion of a predetermined shape is defined; a light receiving surface being opposite to the operation surface in which a light receiving portion is defined; and side surfaces connecting the operation surface and the light receiving surface; a light shielding layer covering the operation surface except for the illuminating portion, the light receiving surface except for the light receiving portion, and the side surfaces; a reflection layer provided between the light shielding layer and the control element body; and a light source configured to feed an illumination light toward the light receiving portion. 
    
    
     
       BRIEF EXPLANATION OF DRAWINGS 
         FIG. 1  is a perspective view showing an electronic musical instrument according to an exemplary embodiment of the invention. 
         FIG. 2  is an exploded perspective view showing a musical pad unit according to the exemplary embodiment. 
         FIG. 3  is a cross-sectional view showing a pad body according to the exemplary embodiment. 
         FIG. 4  is a plan view showing an operation surface of the pad body according to the exemplary embodiment. 
         FIG. 5  is a bottom plan view showing a light receiving surface of the pad body according to the exemplary embodiment. 
         FIG. 6  is a schematic cross-sectional view showing how a reflection layer and a light shielding layer of the exemplary embodiment are arranged. 
         FIG. 7  is an enlarged cross-sectional view showing structures of the reflection layer and the light shielding layer of the exemplary embodiment. 
         FIG. 8  is a schematic cross-sectional view showing optical paths of illumination light of the exemplary embodiment. 
         FIG. 9  is a schematic cross-sectional view showing optical paths of illumination light according to another exemplary embodiment of the invention. 
         FIG. 10  is a schematic cross-sectional view showing optical paths of illumination light according to still another exemplary embodiment of the invention. 
     
    
    
     DESCRIPTION OF EMBODIMENT(S) 
     An exemplary embodiment of the invention will be described below with reference to attached drawings. 
     As shown in  FIG. 1 , an electronic musical instrument  10  includes a control panel  11  and control elements  12  provided on the control panel  11 . The control elements  12  are configured to be operated to play pre-stored music and sound effect data and output the data to an external sound system. The control elements  12  include multiple buttons  13  for function selection, knobs  14  for adjusting various parameters, and a musical pad unit  30  including total sixteen block-shaped pads  20  for playing music, which are arranged four vertically and four horizontally. 
     Various functions (e.g. playing music and sound effect data, effect processing, and changing playing conditions of music pieces currently played) can be assigned in advance to respective pads  20  of the electronic musical instrument  10 . During musical performance, these functions can be performed through pushing and keying operations on respective pads  20 . 
     The pads  20  of the musical pad unit  30 , which are each a self-illuminating control element according to the invention, are configured to be luminous in a predetermined color(s) in accordance with functions set for respective pads. 
     As shown in  FIG. 2 , the musical pad unit  30  includes a pad molded body  31  (an integrally molded component of the pads  20 ), a frame  32 , a pressure-sensitive sensor  33 , a spacer  34 , and a board  35 . 
     The pad molded body  31 , which is a molded component made of a light-transmissive silicone resin, includes the above-described sixteen pads  20 . The pads  20  are each a rectangular block-shaped component. 
     The frame  32 , which is a flat box-shaped component having a top surface provided with openings corresponding to the pads  20 , receives the pad molded body  31  from a backside to expose the pads  20  on the top surface, thereby allowing operations on the pads  20  from an outside. 
     The pressure-sensitive sensor  33  is held together with the spacer  34  between a bottom side of the pad molded body  31  and the board  35 . 
     The pressure-sensitive sensor  33  includes electrodes corresponding to respective pads  20 . Each of the electrodes is pressed by a bottom side of the pad molded body  31 , thereby enabling to independently detect the pushing operation on corresponding one of the pads  20  from an outside. 
     The spacer  34  is formed in grids corresponding to the respective pads  20  and is disposed to secure a desired gap between the pressure-sensitive sensor  33  and the board  35  in each grid. 
     The board  35  is provided with illumination light sources  36  each using a multi-color LED element at the center of each of sections corresponding to the respective pads  20 . 
     When the light source  36  emits light, the illumination light is guided to the bottom side of the pad molded body  31  through corresponding one of the grids of the spacer  34  and corresponding one of through holes in the pressure-sensitive sensor  33  to illuminate corresponding one of the pads  20  from a bottom side thereof. 
     As shown in  FIG. 3 , the pads  20  each include a rectangular block-shaped pad body  21  made of a silicone resin. 
     The pad body  21  includes an operation surface  22  and a light receiving surface  23  on a top side and a bottom side opposite the top side, respectively, as well as four side surfaces  24  connecting the operation surface  22  and the light receiving surface  23 . 
     As shown in  FIG. 4 , on the operation surface  22 , an illuminating portion  25  for luminescent display of a predetermined picture pattern on the top side of the pad  20  is defined. In the present exemplary embodiment, the illuminating portion  25  is in a form of a band of a predetermined width that defines a rectangular frame-shaped area continuous along an outer periphery of the operation surface  22 . 
     As shown in  FIG. 5 , on the light receiving surface  23 , a light receiving portion  26  for receiving the illumination light from the light source  36  into the pad body  21  is defined, and a pair of transmitting portions  27  formed across the light receiving portion  26  are formed. In the present exemplary embodiment, the light receiving portion  26  is in a form of a rectangular area defined at the center of the light receiving surface  23 . The pair of transmitting portions  27 , each of which is a substantially C-shaped projection rising from the light receiving surface  23 , are formed in a face-to-face manner to surround the light receiving portion  26 . 
     A plurality of (sixteen in total) pads  20  are two-dimensionally connected at bottom bases  28  thereof to form an integrally molded component (i.e. the pad molded body  31 ). 
     Each pad  20  also includes a reflection layer  41  and a light shielding layer  42  that are double-layered on the surface of the pad body  21 . 
     As shown in  FIG. 6 , the double-layered reflection layer  41  and light shielding layer  42  almost entirely cover the surface of the pad body  21 , namely, almost the entirety of the operation surface  22 , a part of the light receiving surface  23  including the transmitting portions  27 , and the side surfaces  24 . 
     It should however be noted that the reflection layer  41  and the light shielding layer  42  are not formed on the section defining the illuminating portion  25  on the operation surface  22  and the section defining the light receiving portion  26  on the light receiving surface  23 , so that the pad body  21  is exposed at the illuminating portion  25  and the light receiving portions  26 . 
     The thus double-layered reflection layer  41  and light shielding layer  42  are each formed by applying a paint on the pad body  21 . In the present exemplary embodiment, the reflection layer  41  and the light shielding layer  42  are formed using a white paint and a black paint, respectively. 
     As shown in  FIG. 7 , the operation surface  22  (except for the section defining the illuminating portion  25 ) and the side surfaces  24  of the pad body  21  are provided with the double-layered reflection layer  41  and light shielding layer  42 . 
     In order to form the reflection layer  41  and the light shielding layer  42 , the white paint is initially applied on the surface of the pad body  21  and is dried to form the reflection layer  41 . Subsequently, the black paint is applied on the surface of the reflection layer  41  and is dried to form the light shielding layer  42 . 
     These paints are uniformly applied on the entirety of the operation surface  22  (including the section of the illuminating portion  25 ) and the side surfaces  24 . These paints are optionally applied for a plurality of times. 
     Subsequently, the reflection layer  41  and the light shielding layer  42  in the section of the illuminating portion  25  are removed. The reflection layer  41  and the light shielding layer  42  can be removed using, for instance, laser processing, mechanical polishing, and/or a solvent. The pad body  21  is thus exposed at the illuminating portion  25 . 
     The double-layered reflection layer  41  and light shielding layer  42  are also provided on the light receiving surface  23  except for the section of the light receiving portion  26 . 
     The reflection layer  41  and the light shielding layer  42  on the light receiving surface  23  are formed in the same manner as the reflection layer  41  and the light shielding layer  42  on the operation surface  22  described above, where, after the paints are applied to form the reflection layer  41  and the light shielding layer  42 , the paints in the section of the light receiving portion  26  are removed to expose the pad body  21  at the light receiving portion  26 . 
     According to the present exemplary embodiment, the following advantages can be achieved. 
     In the present exemplary embodiment, the pad  20  (the self-illuminating control element) includes the light-transmissive pad body  21  (control element body) having the operation surface  22  defined thereon with the illuminating portion  25  of a predetermined shape, the light receiving surface  23  defining the light receiving portion  26  and provided opposite the operation surface  22 , and the side surfaces  24  connecting the operation surface  22  and the light receiving surface  23 . Further, the pad  20  includes the light shielding layer  42  covering the operation surface  22  except for the section for the illuminating portion  25 , the light receiving surface  23  except for the section for the light receiving portion  26 , and the side surfaces  24 , the reflection layer  41  formed between the light shielding layer  42  and the pad body  21 , and the light source  36  for feeding the illumination light toward the light receiving portion  26 . 
     According to the present exemplary embodiment, the illumination light from the light source  36  brightly illuminates the picture pattern formed by the illuminating portion  25  on the operation surface  22 . 
     As shown in  FIG. 8 , the illumination light from the light source  36  enters the pad body  21  through the light receiving portion  26  and is partially outputted through the illuminating portion  25  to an outside (optical path L 1 ). The illumination light cannot go through the area surrounding the illuminating portion  25 , since the area is covered with the light shielding layer  42 . 
     Accordingly, the picture pattern formed by the illuminating portion  25  is illuminated on the operation surface  22  against a black background of the light shielding layer  42 . Meanwhile, since the side surfaces  24  and a part of the light receiving surface  23  outside the light receiving portion  26  are covered with the light shielding layer  42 , the illumination of each of the pads  20  is avoidable from reaching other neighboring pads  20 . 
     In the present exemplary embodiment, the reflection layer  41  is formed between the side surfaces  24  of the pad body  21  and the light shielding layer  42 . Accordingly, a part of the illumination light having entered through the light receiving portion  26  is reflected by the reflection layer  41  on the side surfaces  24  to be outputted through the illuminating portion  25  to an outside (optical path L 2 ). Accordingly, brightness of the picture pattern formed by the illuminating portion  25  is higher by an amount of the light through the optical path L 2  than brightness of the picture pattern formed by the illuminating portion  25  only with the light through the optical path L 1 . 
     Further, in the present exemplary embodiment, the reflection layer  41  between the pad body  21  and the light shielding layer  42  is provided not only on the side surfaces  24  but also on the operation surface  22  and the light receiving surface  23 . Accordingly, after entering through the light receiving portion  26  and being reflected by the reflection layer  41  on the operation surface  22 , a part of the illumination light is then further reflected by the reflection layer  41  on the light receiving surface  23  and is outputted through the illuminating portion  25  to an outside (optical path L 3 ). 
     Accordingly, the picture pattern formed by the illuminating portion  25  can be made sufficiently bright by the combined light beams through the optical paths L 1 , L 2 , L 3 . 
     In the present exemplary embodiment, the reflection layer  41  is formed as a film by applying the paint on the surface of the pad body  21  and the light shielding layer  42  is formed as a film by applying the paint on the surface of the reflection layer  41 . 
     Accordingly, the double-layered reflection layer  41  and light shielding layer  42  can be easily and inexpensively formed. 
     In the present exemplary embodiment, the reflection layer  41  and the light shielding layer  42  are formed using the white paint and the black paint, respectively. 
     Accordingly, the reflection layer  41  and the light shielding layer  42 , which can be formed without requiring any special paint, can be easily and inexpensively formed. 
     In the present exemplary embodiment, the pad body  21  is a molded component made of silicone resin. 
     Accordingly, while providing an appropriate touch feeling of the pad  20 , a sufficient pressing force can be transmitted to the pressure-sensitive sensor  33 . 
     In the present exemplary embodiment, the musical pad unit  30  including the multiple pads  20  is configured as a laminate of the board  35  provided thereon with the light source  36 , the spacer  34  and the pressure-sensitive sensor  33  provided on the surface of the board  35 , and the pad body  21  disposed on the surface of the pressure-sensitive sensor  33 . 
     Accordingly, the push and keying operations on the operation surface  22  of the pad body  21  of each of the pads  20  are detectable by the pressure-sensitive sensor  33  while illuminating the illuminating portion  25  with the illumination light from the light source  36 , thereby achieving desired functions of the pads  20  with a simple structure. 
     Especially, since a transmitting portion  27  configured to be brought into contact with the pressure-sensitive sensor  33  is provided on the light receiving surface  23  of the pad body  21  in the present exemplary embodiment, the detection by the pressure-sensitive sensor  33  can be reliably performed. Further, since the transmitting portion  27  is formed in a pair of substantially C-shaped projections rising from the light receiving surface  23  and surrounding the light receiving portion  26 , the transmitting portion  27  can trap the illumination light from the light source  36  to prevent leakage to an outside. 
     It should be noted that the invention is not limited to the above-described exemplary embodiment but includes modifications and the like as long as such modifications and the like are compatible with an object of the invention. 
     In the exemplary embodiment illustrated in the above  FIGS. 1 to 8 , the double-layered reflection layer  41  and light shielding layer  42  are formed on each of the operation surface  22 , the light receiving surface  23 , and the side surfaces  24 , so that the illumination light reaches the illuminating portion  25  through the optical paths L 1 , L 2 , L 3 . 
     However, the double-layered reflection layer  41  and light shielding layer  42 , which are not necessarily formed on all of the operation surface  22 , the light receiving surface  23 , and the four side surfaces  24  in the invention, are optionally partially omitted. 
       FIG. 9  shows another exemplary embodiment of the invention. 
     In the present exemplary embodiment, a pad  20 A (self-illuminating control element) includes a pad body  21 A (control element body). 
     The pad body  21 A includes: the double-layered reflection layer  41  and light shielding layer  42  on the four side surfaces  24 ; and only the light shielding layer  42  on the operation surface  22  and the light receiving surface  23 . The reflection layer  41  is omitted on the operation surface  22  and the light receiving surface  23 . 
     In the exemplary embodiment shown in  FIG. 9 , in addition to the illumination light through the optical path L 1  emitted by the light source  36  to directly reach the illuminating portion  25 , the illumination light through the optical path L 2  emitted by the light source  36  and reflected by the reflection layer  41  on the side surfaces  24  to reach the illuminating portion  25  can be obtained, so that the illumination of the pad  20 A can be more brightened by an amount of the light from the optical path L 2 . 
       FIG. 10  shows still another exemplary embodiment of the invention. 
     In the present exemplary embodiment, a pad  20 B (self-illuminating control element) includes a pad body  21 B (control element body). 
     The pad body  21 B includes: the double-layered reflection layer  41  and light shielding layer  42  on the operation surface  22  and the light receiving surface  23 ; and only the light shielding layer  42  on the four side surfaces  24 . But the reflection layer  41  is omitted on the four side surfaces  24 . 
     In the exemplary embodiment shown in  FIG. 10 , in addition to the illumination light through the optical path L 1  emitted by the light source  36  to directly reach the illuminating portion  25 , the illumination light through the optical path L 3  emitted by the light source  36  and sequentially reflected by the reflection layer  41  on the operation surface  22  and the reflection layer  41  on the light receiving surface  23  to reach the illuminating portion  25  can be obtained, so that the illumination of the pad  20 B can be more brightened by an amount of the light from the optical path L 3 . 
     The illuminating portion  25  and the light receiving portion  26  are formed by partially removing the reflection layer  41  and the light shielding layer  42  formed by the paint applied on the surface of the pad body  21  in the above exemplary embodiment. However, the illuminating portion  25  and the light receiving portion  26  are not necessarily formed by removing the reflection layer  41  and the light shielding layer  42 . For instance, in some embodiments, after masking is applied in advance on the sections of the illuminating portion  25  and the light receiving portion  26  and then the paints for the double-layered reflection layer  41  and light shielding layer  42  are applied, the masking is removed to expose the surface of the pad body  21 . Alternatively, the double-layered reflection layer  41  and light shielding layer  42  are optionally formed only on the surface except for the sections of the illuminating portion  25  and the light receiving portion  26  by coating or other methods. 
     The reflection layer  41  and the light shielding layer  42  are formed by applying the white paint and the black paint, respectively, on the surface of the pad body  21  in the above exemplary embodiments. But the reflection layer  41  and the light shielding layer  42  are not necessarily formed by applying the black and white paints. For instance, the reflection layer  41  is optionally formed using a light-color paint exhibiting reflectivity or a paint dispersed with a light-reflective material. The light shielding layer  42  is optionally formed using a dark-color paint exhibiting light-blocking property or a paint dispersed with a light-absorbing material. 
     Further alternatively, the reflection layer  41  and the light shielding layer  42  are optionally formed through other processes (e.g. lamination of a thin film) instead of applying a paint. 
     The operation surface  22  and the light receiving surface  23  are on the rectangular block-shaped pad body  21  and are opposed in parallel in the above exemplary embodiment. But the operation surface  22  and the light receiving surface  23  are optionally slanted with each other. In addition, the operation surface  22 , the light receiving surface  23 , and the side surfaces  24  are not necessarily flat surfaces but are optionally each independently a concave or convex curve surface. In any case, it is only necessary that the surfaces are configured so that the illumination light emitted from the light source  36  onto the light receiving portion  26  is reflected by the reflection layer  41  to reach the illuminating portion  25 . 
     The pad body  21  is a molded component of a light-transmissive silicone resin in the above exemplary embodiment. But the pad body  21  is optionally a molded component of other light-transmissive synthetic resin material. Alternatively, the pad body  21  is optionally not molded using a die but is produced by a machining process. The light-transmissive pad body  21  is optionally transparent, translucent, or colored (e.g. milky white), In other words, the pad body  21  is light-transmissive in any manner as long as a desired illumination light can be provided when the light reaches the illuminating portion  25  after passing through the light receiving portion  26  and the pad body  21 . 
     The transmitting portion  27  is provided on the light receiving surface  23  of the pad body  21  in the above exemplary embodiment. But the transmitting portion  27  is not necessarily formed in the same shape as that in the above exemplary embodiment. In addition, the transmitting portion  27  is optionally omitted to directly press the pressure-sensitive sensor  33  with the light receiving surface  23 . 
     In the above exemplary embodiment, the plurality of pads  20  are integrated to form the musical pad unit  30 . However, the pad  20  is optionally a single component. 
     The arrangement of the self-illuminating control element is exemplified by the pad  20  and the musical pad unit  30  for pushing and/or keying operation in the above exemplary embodiment. But the arrangement of the self-illuminating control element is also applicable in order to provide other self-illuminating control elements  12  (e.g. the button  13  and the knob  14 ) provided to the electronic musical instrument  10 . In such an application, the self-illuminating control elements are optionally used in combination with a switch and/or a variable resistor suitable for the specific application instead of the board  35  and the pressure-sensitive sensor  33 . 
     Further, the self-illuminating control element of the invention is also usable not only in the electronic musical instrument  10  but also as a self-illuminating control element in disc jockey instruments (DJ instruments) and sound equipment. 
     The picture pattern of the illumination of the self-illuminating control element (the picture pattern drawn by light emission of the illuminating portion  25  formed on the operation surface  22 ) is exemplarily a character, an icon, or a pictogram indicating a function of the control element, if the function is fixed. In contrast, when a plurality of functions are assignable to the control element, in place of the specific icon indicating its function, the illuminated picture pattern is optionally an abstract one such as a frame line extending along the contour of the operation surface  22  (e.g. the rectangular frame-shaped illuminating portion  25  shown in  FIG. 4 ) and a center point indicating the position of the operation surface  22 . 
     EXPLANATION OF CODES 
       10  . . . electronic musical instrument,  11  . . . control panel,  12  . . . control elements,  13  . . . button,  14  . . . knob,  20 ,  20 A,  20 B . . . pad (self-illuminating control element),  21 ,  21 A,  21 B . . . pad body (control element body),  22  . . . operation surface,  23  . . . light receiving surface,  24  . . . side surface,  25  . . . illuminating portion,  26  . . . light receiving portion,  27  . . . transmitting portion,  28  . . . base,  30  . . . musical pad unit (self-illuminating control element),  31  . . . pad molded body,  32  . . . frame,  33  . . . pressure-sensitive sensor,  34  . . . spacer,  35  . . . board,  36  . . . light source,  41  . . . reflection layer,  42  . . . light shielding layer, L 1 , L 2 , L 3  . . . optical path