Keyboard device and electronic device

Abstract

Suppresses the decrease in light intensity. [Solution] A keyboard device includes a light source and a plurality of keycaps capable of emitting light by light irradiated from the light source. The keyboard device includes a base plate supporting the keycaps on the upper side, and a membrane sheet having an upper contact sheet, a lower contact sheet, and a spacer sheet sandwiched between the upper contact sheet and the lower contact sheet, laminated on the upper surface of the base plate, the upper contact sheet, the lower contact sheet, and the spacer sheet being optically transparent, a light reflecting layer being provided on the upper surface of the upper contact sheet, and the membrane sheet is arranged such that a portion of at least one of the upper contact sheet, the lower contact sheet, and the spacer sheet is disposed below the keycaps, and the membrane sheet has a light diffusing pattern on the surface of the portion disposed below the keycaps.

Description

[Technical field]

[0001] The present invention relates to a keyboard device and an electronic device equipped with a keyboard device. [Background technology]

[0002] Electronic devices such as notebook PCs are sometimes equipped with keyboard devices capable of emitting light from key caps (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6868716 Summary of the Invention [Problem to be solved by the invention]

[0004] The keyboard device described above often adopts a configuration in which a three-layer membrane sheet, a base plate that supports the keycaps, and a backlight module are stacked from top to bottom. The backlight module has a light source near the center of the keyboard device. Light from the light source is guided left and right by a light guide plate, and emits light to each keycap through through holes formed in the base plate and the membrane sheet.

[0005] Generally, each layer of the membrane sheet is made of a transparent PET film. A luminescence experiment was conducted in a darkroom on this keyboard device. It was confirmed that light was leaking into the membrane sheet from the through-holes under the keycaps, and this was found to be a factor in reducing the amount of light irradiated onto the keycaps.

[0006] The present invention has been made in consideration of the problems with the conventional technology described above, and has an object to provide a keyboard device and an electronic device equipped with a keyboard device that can suppress a decrease in the amount of light. [Means for solving the problem]

[0007] A keyboard device according to a first aspect of the present invention is a keyboard device comprising a light source and a plurality of keycaps capable of emitting light by light irradiated from the light source, and comprising a base plate supporting the keycaps on their upper sides, and a membrane sheet having an upper contact sheet, a lower contact sheet, and a spacer sheet sandwiched between the upper contact sheet and the lower contact sheet, and laminated on the upper surface of the base plate, wherein the upper contact sheet, the lower contact sheet, and the spacer sheet are optically transparent, and a light reflecting layer is provided on the upper surface of the upper contact sheet, and the membrane sheet has a portion of at least one of the upper contact sheet, the lower contact sheet, and the spacer sheet positioned below the keycaps, and has a light diffusion pattern on the surface of the portion positioned below the keycaps.

[0008] An electronic device according to a second aspect of the present invention comprises a keyboard device facing an upper surface of the housing, the keyboard device having a housing, a light source, and a plurality of keycaps capable of emitting light with light irradiated from the light source, the keyboard device comprising a base plate supporting the keycaps on the upper side, an upper contact sheet, a lower contact sheet, and a spacer sheet sandwiched between the upper contact sheet and the lower contact sheet, and a membrane sheet laminated on the upper surface of the base plate, the upper contact sheet, the lower contact sheet, and the spacer sheet being optically transparent, a light reflecting layer being provided on the upper surface of the upper contact sheet, and the membrane sheet having a portion of at least one of the upper contact sheet, the lower contact sheet, and the spacer sheet being arranged below the keycaps, and having a light diffusion pattern on the surface of the portion arranged below the keycaps. Effect of the Invention

[0009] According to the above aspect of the present invention, a decrease in the amount of light can be suppressed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a plan view of an electronic device according to an embodiment. [Diagram 2] FIG. 2 is a schematic side cross-sectional view of a key cap and its surroundings of the keyboard device according to the first embodiment. [Diagram 3] FIG. 3 is a schematic plan view of the keycap and its surroundings shown in FIG. [Figure 4] FIG. 4 is a bottom view of the keyboard device shown in FIG. [Diagram 5] FIG. 5 is a schematic side cross-sectional view of a key cap and its surroundings of a keyboard device according to the second embodiment. [Figure 6] FIG. 6 is a schematic side cross-sectional view of a key cap and its surroundings of a keyboard device according to the third embodiment. [Figure 7] FIG. 7 is a schematic plan view of the keycap and its surroundings shown in FIG. [Figure 8] FIG. 8 is a schematic side cross-sectional view of a light source and its surroundings of a keyboard device equipped with a membrane sheet having a bulging portion. [Figure 9] FIG. 9 is a schematic cross-sectional side view of a light source and its periphery of a keyboard device equipped with a membrane sheet having a bent portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a keyboard device and an electronic device including the keyboard device according to the present invention will be described in detail with reference to the accompanying drawings.

[0012] FIG. 1 is a plan view of an electronic device 10 according to an embodiment.

[0013] As shown in Fig. 1, electronic device 10 includes a housing 14 equipped with a keyboard device 12, and a display housing 18 equipped with a display 16. In this embodiment, electronic device 10 is illustrated as a clamshell-type notebook PC in which housing 14 and display housing 18 are connected by a hinge 20 so as to be relatively rotatable. Fig. 1 shows a usage form in which display housing 18 is opened from housing 14. Electronic device 10 is not limited to a clamshell type, so long as it is an electronic device equipped with a keyboard device.

[0014] In the following, the housing 14 and each element mounted thereon, such as the keyboard device 12, will be described based on the direction as seen by a user using the keyboard device 12 while looking at the display 16, with the front side being referred to as the front, the back side being referred to as the rear, the thickness direction being the top and bottom, and the width direction being the left and right.

[0015] The display housing 18 is a flat box that is thinner than the housing 14, and has a display 16 on the front side. The display 16 is made of, for example, an organic electroluminescence (EL) display or liquid crystal display. The lower end of the display housing 18 is connected to the rear end of the housing 14 via a hinge 20.

[0016] The housing 14 is a thin, flat box, and the keyboard device 12 faces an upper surface 14a of the housing 14. Inside the housing 14, a motherboard on which a CPU, a memory, etc. are mounted, a speaker device, a cooling device, a battery device, etc. are housed.

[0017] The keyboard device 12 is supported on the upper part of a housing 14. The keyboard device 12 has a plurality of key switches 24. The keyboard device 12 is an isolation type keyboard device in which a frame 26 separates the periphery of a key cap 24a, which serves as the operating surface of each key switch 24.

[0018] The frame 26 is a mesh-like frame body made of resin, metal, or the like. The housing 14 of this embodiment is composed of a cover member 27 that forms the top surface 14a and the four peripheral side surfaces, and a cover member 28 that closes the bottom opening of the cover member 27. The frame 26 is integrally molded with the cover member 27 that forms the top surface 14a. The frame 26 may be formed separately from the cover member 27. The frame 26 has a plurality of key holes 26a into which the key caps 24a are inserted so as to be movable up and down. The key holes 26a are the portions of the frame 26 that are surrounded by a horizontal frame portion 26b extending in the left-right direction and a vertical frame portion 26c extending in the front-rear direction.

[0019] Next, a specific example of the configuration of the keyboard device 12 will be described.

[0020] The keyboard device 12 will be described below in the order of a keyboard device 12A according to a first embodiment (see FIG. 2), a keyboard device 12B according to a second embodiment (see FIG. 5), and a keyboard device 12C according to a third embodiment (see FIG. 6).

[0021] Fig. 2 is a schematic side cross-sectional view of the keycap 24a and its surroundings of the keyboard device 12A according to the first embodiment. The frame 26 is omitted in Fig. 2, and the same is true for Figs. 5 and 6. Fig. 3 is a schematic plan view of the keycap 24a and its surroundings shown in Fig. 2. In Fig. 3, only the outline of the keycap 24a is shown by a two-dot chain line, and the same is true for Fig. 7. Fig. 4 is a bottom view of the keyboard device 12A shown in Fig. 3.

[0022] As shown in FIGS. 2 and 3, the keyboard device 12A includes a plurality of key switches 24, a base plate 30, a membrane sheet 31, and a light-emitting module 32.

[0023] Each key switch 24 has a key cap 24a and a guide mechanism 24b. The guide mechanism 24b is a scissor mechanism that supports the key cap 24a on the upper surface 30a side of the base plate 30 so that the key cap 24a can move up and down. A rubber dome 24c stands upright in the center of the guide mechanism 24b (see FIG. 3). The rubber dome 24c is a dome-shaped member made of a flexible elastic material such as silicone rubber. The rubber dome 24c presses the membrane sheet 31 when the key cap 24a is pressed down, and returns the key cap 24a to its original position when the pressing operation of the key cap 24a is released.

[0024] The base plate 30 is a thin plate that supports the key switches 24 and the frame 26. The base plate 30 extends over substantially the entire outer shape of the keyboard device 12A. The base plate 30 can be made of a metal plate-like member, such as a thin stainless steel plate or aluminum plate, that has been cut and punched.

[0025] The membrane sheet 31 is a three-layer switch sheet whose contacts close when pressed. The membrane sheet 31 extends to a position overlapping below all of the key switches 24. The membrane sheet 31 is laminated on the upper surface 30a of the base plate 30. The membrane sheet 31 has an upper contact sheet 33, a lower contact sheet 34, and a spacer sheet 35 sandwiched between the contact sheets 33, 34.

[0026] The contact sheets 33, 34 have a predetermined conductive pattern on each of their opposing surfaces, which face each other across the space formed by the spacer sheet 35. The contact sheets 33, 34 can be configured, for example, by printing a conductive ink such as silver paste or carbon paste on the surface of a transparent PET film. The contact sheets 33, 34 are formed of a transparent PET film, and thus have optical transparency in the surface direction and in the thickness direction perpendicular to the surface direction. The contact sheets 33, 34 may be formed of materials other than a transparent PET film, so long as they have optical transparency. The contact sheets 33, 34 are formed extremely thin, for example, about 0.07 mm, and have high flexibility.

[0027] The spacer sheet 35 provides insulation between the contact sheets 33 and 34. The spacer sheet 35 can be formed of, for example, a transparent PET film like the contact sheets 33 and 34, and has optical transparency. As long as the spacer sheet 35 also has optical transparency, it may be formed of a material other than a transparent PET film. The thickness of the spacer sheet 35 can be formed to, for example, about 0.06 mm.

[0028] The membrane sheet 31 has a light reflecting layer 36 and a decorative layer 37 laminated on the upper surface 33a of the upper contact sheet 33. The light reflecting layer 36 can be configured to cover the upper surface 33a with a light reflective paint formed in a white or silver color, for example. The light reflecting layer 36 is intended to efficiently guide the light that has entered the membrane sheet 31 from the light emitting module 32 within the membrane sheet 31. As shown in the configuration examples of Figures 5 and 6 described later, the membrane sheet 31 may intentionally introduce light from a light source 48. The membrane sheet 31 may unintentionally introduce light that is diffusely reflected by the light diffusion pattern 42. The membrane sheet 31 may unintentionally introduce light that is diffusely reflected by the light diffusion pattern 42 and further reflected by the key cap 24a or the guide mechanism 24b. The light reflecting layer 36 is also intended to prevent the light guided within the membrane sheet 31 from being absorbed by the black decorative layer 37. The decorative layer 37 is a surface layer for preventing the membrane sheet 31 exposed from the gap between the keycaps 24a and the frame 26 from being conspicuous in appearance. The decorative layer 37 can be configured by covering the upper surface of the light reflecting layer 36 with black paint, for example.

[0029] When the key cap 24a is pressed down, the upper contact sheet 33 of the membrane sheet 31 is pressed down by the rubber dome 24c and elastically deforms. As a result, the conductive pattern (movable contact) on the upper contact sheet 33 abuts against the conductive pattern (fixed contact) on the lower contact sheet 34, closing the contact. This causes the membrane sheet 31 to output a predetermined input signal according to the type of key.

[0030] As shown in FIG. 2 and FIG. 3, in this embodiment, the membrane sheet 31 has a through hole 38 directly below each key cap 24a. The through hole 38 is, for example, substantially rectangular in plan view. Inside the through hole 38, the base plate 30 is arranged in a bridge shape, and the membrane sheet 31 is also arranged on the upper surface 30a of this portion in a floating island shape. The through hole 38 allows light from the light emitting module 32 to pass through to the key cap 24a. The through hole 38 is also used to insert hooks 39 protruding from the upper surface 30a of the base plate 30. For example, four hooks 39 are provided in each portion located below each key switch 24. Each hook 39 supports an axis pin of the guide mechanism 24b. The base plate 30 has a through hole 30c. The through hole 30c communicates with the through hole 38 and allows light from the light emitting module 32 to pass through the through hole 38.

[0031] In this embodiment, the membrane sheet 31 has an extension 40 that is a part of the upper contact sheet 33 that protrudes to the inside of the through hole .

[0032] The extension portion 40 is a small piece of the transparent PET film forming the upper contact sheet 33 protruding into the inner space of the through hole 38. The extension portion 40 is disposed below the key cap 24a. The light reflecting layer 36 and the decorative layer 37 are not provided on the upper surface 33a of the extension portion 40. In other words, the transparent PET film is exposed in the extension portion 40. As shown by the two-dot chain line in FIG. 2, the extension portion 40 can also be provided on the lower contact sheet 34 and the spacer sheet 35. In other words, the extension portion 40 can be provided on at least one sheet among the contact sheets 33, 34 and the spacer sheet 35. The extension portion 40 can be formed to protrude backward from the inner wall on the front side of the through hole 38 (see FIG. 4). As shown by the two-dot chain line in FIG. 4, the extension portion 40 can also be provided on the rear side and the left and right inner walls of the through hole 38.

[0033] A light diffusion pattern 42 is provided on the surface of the extension 40. The light diffusion pattern 42 can be provided on the lower surface 33b of the upper contact sheet 33 that forms the extension 40. The light diffusion pattern 42 can be provided on the upper surface of the upper contact sheet 33 that forms the extension 40, or on both the upper and lower surfaces. The light diffusion pattern 42 is a convex or concave pattern formed on the surface of the upper contact sheet 33. The light diffusion pattern 42 is a pattern for diffusely reflecting and diffusing the light guided inside the upper contact sheet 33, thereby increasing the amount of light directed toward the key cap 24a. The light diffusion pattern 42 can be formed, for example, in a striped slit pattern as shown in FIG. 3. The light diffusion pattern 42 can also be formed in a circular or rectangular dot pattern as shown in FIG. 7. This allows the extension 40 to emit light from the key cap 24a with the light diffused by the light diffusion pattern 42.

[0034] The light-emitting module 32 is a backlight module for illuminating each keycap 24a. The light-emitting module 32 is laminated on the lower surface 30b of the base plate 30. The light-emitting module 32 includes a light-guiding member 44, an upper reflective sheet 45, a lower reflective sheet 46, and a light source 48.

[0035] The light guide member 44 may be made of a sheet made of a translucent resin such as PET, polycarbonate, or acrylic. The light guide member 44 guides the light emitted from the light source 48. The light guide member 44 and the reflective sheets 45, 46 extend to a position overlapping below all the key switches 24. The light guide member 44 is provided with a light diffusion pattern 42 on the surface of a portion located below each key cap 24a. The light diffusion pattern 42 may be provided on a lower surface 44a of the light guide member 44 located directly below the through hole 30c. The light diffusion pattern 42 may be provided on the upper surface of the light guide member 44, or on both the upper and lower surfaces.

[0036] The upper reflection sheet 45 is laminated on the upper surface of the light guide member 44. The lower reflection sheet 46 is laminated on the lower surface of the light guide member 44. The reflection sheets 45, 46 cover the surface of the light guide member 44 to suppress light leakage from the light guide member 44, and maintain the amount of light inside the light guide member 44 by applying a white coating to the surface in contact with the light guide member 44. The reflection sheets 45, 46 can be made of a sheet made of a resin such as PET, polyester, or polyolefin having high reflectivity. The upper reflection sheet 45 is cut out at a position that overlaps the through hole 30c in the vertical direction. As a result, the light guide member 44 can pass the light diffused by the light diffusion pattern 42 through the through holes 30c, 38, and emit light to the key cap 24a.

[0037] The light source 48 can be configured, for example, with a light emitting diode (LED). The light source 48 is attached, for example, to approximately the center in the left-right direction of the light guide member 44, and a plurality of light sources 48 are arranged in parallel in the front-rear direction (see FIG. 4). The light source 48 is mounted on the upper surface of a flexible substrate (FPC: Flexible printed circuits) 50. The flexible substrate 50 is disposed along the lower surface of the lower reflection sheet 46, and one end is electrically connected to the motherboard.

[0038] In this embodiment, the light-emitting module 32 has a hole 52 that penetrates the lower reflective sheet 46 and the light-guiding member 44 and has a rear surface that is blocked by the upper reflective sheet 45. The light source 48 is inserted into the hole 52 and can irradiate light sideways from light irradiation surfaces 48a provided on the left and right sides. The light emitted from the light source 48 is guided in the left-right direction by the light-guiding member 44 and can irradiate each keycap 24a from the back side.

[0039] 4 denotes mounting holes formed at appropriate positions on the keyboard device 12 A. Screws for fixing the keyboard device 12 A to the frame 26 are inserted through the mounting holes 54.

[0040] As described above, the keyboard device 12A of the present embodiment includes the light source 48, the multiple keycaps 24a that can emit light by the light irradiated from the light source 48, the base plate 30 that supports the keycaps 24a on the upper surface 30a side, and the membrane sheet 31 that is laminated on the upper surface 30a of the base plate 30. In the keyboard device 12A, the contact sheets 33, 34 and the spacer sheet 35 that constitute the membrane sheet 31 have optical transparency, and a light reflecting layer 36 is provided on the upper surface 33a of the upper contact sheet 33. In the membrane sheet 31, a part (extension portion 40) of at least one sheet (for example, the upper contact sheet 33) among the contact sheets 33, 34 and the spacer sheet 35 is disposed below the keycaps 24a, and the membrane sheet 31 has a light diffusion pattern 42 on the surface of the extension portion 40.

[0041] In such a keyboard device 12A, as shown in FIG. 2, the light L irradiated from the light source 48 to the keycap 24a enters the membrane sheet 31 from the end surface partially exposed in the through hole 38. Here, in the keyboard device 12A, the upper surface 33a of the upper contact sheet 33 located in the uppermost layer of the three-layer sheet constituting the membrane sheet 31 is covered with a light reflecting layer 36. Therefore, the light L introduced into the membrane sheet 31 is efficiently guided while being reflected and diffused in the membrane sheet 31 having optical transparency. This light L is diffusely reflected by the light diffusion pattern 42 provided on the extension portion 40, causing the keycap 24a to emit light. As a result, the keyboard device 12A can prevent the light L introduced into the membrane sheet 31 from leaking and reducing the amount of light, and can cause each keycap 24a to emit light with a sufficient amount of light. The white arrow L in Figure 2 indicates mainly the light guided within the light-guiding member 44 and the membrane sheet 31, and the dotted arrow L indicates mainly the light diffused by the light diffusion pattern 42, and the same is true for Figure 5 and the subsequent figures.

[0042] In particular, the upper surface of the membrane sheet is exposed on the exterior of the keyboard device, and thus has conventionally been covered with black paint (decorative layer 37). For this reason, when light is incident on a conventional membrane sheet, it is absorbed by the black paint and dimmed, which has the problem of easily causing a decrease in the amount of light that illuminates the keycaps 24a. In this regard, the keyboard device 12A provides a light reflecting layer 36 under the decorative layer 37, which makes it possible to avoid dimming caused by absorption by the decorative layer 37 and enables efficient light guidance within the membrane sheet 31.

[0043] The keyboard device 12A may include a light guide member 44 laminated on the lower surface 30b side of the base plate 30. The membrane sheet 31 has through holes 38 below the key caps 24a, through which the light L guided by the light guide member 44 passes to the key caps 24a. In the keyboard device 12A, most of the light L from the light source 48 is irradiated to the key caps 24a from the light diffusion pattern 42 provided on the light guide member 44. On the other hand, a part of the light L diffused from the light guide member 44 is introduced into the membrane sheet 31. However, in the keyboard device 12A, not only is light leakage from the membrane sheet 31 suppressed as described above, but the light is also irradiated to the key caps 24a from the light diffusion pattern 42 provided on the extension portion 40.

[0044] That is, the keyboard device 12A according to the first embodiment can suppress a decrease in the amount of light by simply adding the light reflecting layer 36 and the extension portion 40 to a keyboard device equipped with a general light guiding member 44. Therefore, the keyboard device 12A can be easily applied to backlight type keyboard devices that have been widely used in the past, and can effectively utilize the light that has entered the membrane sheet 31, making it highly versatile.

[0045] Next, a keyboard device 12B according to a second embodiment will be described.

[0046] 5 is a schematic side cross-sectional view of a key cap 24a and its surroundings of a keyboard device 12B according to the second embodiment. In the keyboard device 12B according to the second embodiment, elements having the same or similar functions and effects as those of the keyboard device 12A according to the first embodiment described above are denoted by the same reference numerals and detailed description thereof is omitted, and the same applies to the keyboard device 12C according to the third embodiment.

[0047] The keyboard device 12B shown in FIG. 5 differs from the keyboard device 12A shown in FIG. 2 in that some of the light sources 48 are replaced with light sources 48A. As shown in FIG. 4, in the keyboard device 12A, for example, six light sources 48 are arranged in parallel in the front-rear direction. The light sources 48A of the keyboard device 12B are arranged at the positions indicated by the reference numerals "48" and "48A" in parentheses in FIG. 4, which indicate the light sources. The light sources 48A may be, for example, light sources in which two of the six light sources 48 are replaced with light sources 48A. The ratio of the numbers of the light sources 48 and 48A may be other than the above. The ratio of the numbers of the light sources 48 and 48A may be appropriately set in order to control the amount of light guided by the light guide member 44 and the amount of light guided by the membrane sheet 31 to a predetermined ratio, for example.

[0048] Light source 48A is composed of, for example, an LED, and is similar to other light sources 48 in that it is mounted on the upper surface of a flexible substrate 50. Light source 48A has a different light emission direction (direction of the light emission surface) from light source 48A. Light source 48A has light emission surface 48b on its upper surface, and can emit light upward.

[0049] As shown in FIG. 5, the keyboard device 12A has a hole 52A at a position corresponding to the light source 48A. The hole 52A is deeper than the hole 52. The light source 48A is inserted into the hole 52A. The hole 52A penetrates the lower reflection sheet 46, the light guide member 44, the upper reflection sheet 45, and the base plate 30, and the inner surface is blocked by the membrane sheet 31. The light source 48A inserted into the hole 52A has an upward light irradiation surface 48b facing the lower surface of the membrane sheet 31. Therefore, more light irradiated from the light source 48A is incident on the membrane sheet 31 than on the light guide member 44.

[0050] Therefore, in the keyboard device 12B of this embodiment, the light L emitted upward from the light source 48A is incident on the lower surface of the membrane sheet 31. In the keyboard device 12B, the upper surface 33a of the upper contact sheet 33 located on the uppermost layer of the membrane sheet 31 is also covered with a light reflecting layer 36. Therefore, the light L introduced from the light source 48A to the membrane sheet 31 is efficiently guided while being reflected and diffused in the membrane sheet 31 having optical transparency. This light L is diffused by the light diffusion pattern 42 provided on the extension portion 40, causing the key cap 24a to emit light. On the other hand, the light L emitted from another light source 48 and guided by the light guide member 44 is irradiated from the light diffusion pattern 42 provided on the light guide member 44 to the key cap 24a.

[0051] As a result, in the keyboard device 12B, the light L introduced into the membrane sheet 31 is prevented from leaking and reducing in light quantity, and each keycap 24a can be illuminated with a sufficient amount of light. In the keyboard device 12B, the ratio of the light quantity introduced into the membrane sheet 31 and the light introduced into the light guide member 44 can be adjusted by appropriately adjusting the ratio of the number of light sources 48A to the number of light sources 48. For example, when the keycap 24a is viewed as a whole, it is possible to adjust the amount of light through the membrane sheet 31 to 60% and the amount of light through the light guide member 44 to 40%. Therefore, the keyboard device 12B can be designed, for example, by making the light guide member 44 as thin as possible and supplementing the amount of light that is insufficient with the membrane sheet 31. This has the advantage that the keyboard device 12B can be made thinner overall. In addition, when the thickness of the light guide member 44 is not changed, the keyboard device 12B can also reduce the power consumption by reducing the number of light sources 48, 48A and the current value.

[0052] Next, a keyboard device 12C according to a third embodiment will be described.

[0053] Fig. 6 is a schematic side cross-sectional view of a key cap 24a and its surroundings of a keyboard device 12C according to a third embodiment. Fig. 7 is a schematic plan view of the key cap 24a and its surroundings shown in Fig. 6. In Fig. 7, the rubber dome 24c is omitted.

[0054] 6 differs from the above-described keyboard devices 12A and 12B in that it includes a light-emitting module 32A having a different configuration from the light-emitting module 32 and a hole 52B having a different configuration from the hole portions 52 and 52A. The keyboard device 12C also differs from the above-described configurations in that the membrane sheet 31 does not substantially have a through-hole 38.

[0055] The light-emitting module 32A differs from the above-described light-emitting module 32 in that it does not have a light-guiding member 44, an upper reflection sheet 45, or a lower reflection sheet 46. The light-emitting module 32A can be configured to include substantially only a light source 48 and a flexible substrate 50 on which the light source 48 is mounted. The flexible substrate 50 of the light-emitting module 32A is directly laminated on the lower surface 30b of the base plate 30. Such a keyboard device 12C is configured to guide the light emitted from the light source 48 to each keycap 24a only by the membrane sheet 31 instead of the light-guiding member 44.

[0056] The flexible substrate 50 covers only a portion of the lower surface 30b of the base plate 30. For this reason, in the keyboard device 12C, it is preferable to cover at least the portion of the lower surface 30b of the base plate 30 that is not covered by the flexible substrate 50 with a sheet 56. This covers punched holes and the like formed in the base plate 30. The sheet 56 can be formed of a sheet having the same light reflectivity as the above-mentioned reflective sheets 45, 46.

[0057] The hole 52B opens on the lower surface of the membrane sheet 31 (the lower surface 34a of the lower contact sheet 34) and penetrates the base plate 30. The hole 32B penetrates the base plate 30, the lower contact sheet 34, and the spacer sheet 35, and the inner surface can be closed by the upper contact sheet 33. The light source 48 is inserted into the hole 52B. It is preferable that the light source 48 is installed at a height position where at least the left and right light irradiation surfaces 48b face the end surfaces 34b, 35b of the lower contact sheet 34 and the spacer sheet 35 that form the inner wall surface of the hole 52B. As a result, the light L irradiated laterally from the light irradiation surface 48b of the light source 48 smoothly enters the membrane sheet 31 from the end surfaces 34b, 35b.

[0058] As described above, in the keyboard device 12C of this embodiment, the membrane sheet 31 does not substantially have through holes 38. As shown in Figures 6 and 7, in the keyboard device 12C, the membrane sheet 31 is laid out below each keycap 24a. The membrane sheet 31 thus includes a light diffusion pattern 42 in the portion disposed below the keycap 24a.

[0059] The light diffusion pattern 42 can be provided on at least one of the surfaces of the contact sheets 33, 34 and the spacer sheet 35 located below the keycap 24a. When the light diffusion pattern 42 is provided only on a part of the contact sheets 33, 34 and the spacer sheet 35, only the sheet provided with the light diffusion pattern 42 can be disposed below the keycap 24a. In the configuration example shown in FIG. 6, the light diffusion pattern 42 is provided on each of the surfaces (lower surfaces 33b, 34a) of the contact sheets 33, 34 and the surface (lower surface 35a) of the spacer sheet 35 located below the keycap 24a. The light diffusion pattern 42 can be provided on the upper surfaces of the contact sheets 33, 34 and the spacer sheet 35, or on both the upper and lower surfaces of each of them. This allows the keyboard device 12C to more sufficiently secure the amount of light diffused from the membrane sheet 31 to the keycap 24a.

[0060] Incidentally, in the keyboard device 12C as well, the hooks 49 need to penetrate the membrane sheet 31. For this reason, in the keyboard device 12C, small holes 58 for inserting the hooks 49 are formed in the membrane sheet 31 (see FIGS. 6 and 7). However, the holes 58 can be an obstacle to the guiding and diffusing of light in the membrane sheet 31. Therefore, it is preferable that the holes 58 are formed to a minimum size that surrounds each of the hooks 49. It is preferable that the gap between the inner circumferential surface of the holes 58 and the hooks 49 is set to, for example, 0.3 mm or less.

[0061] Therefore, the keyboard device 12C of this embodiment includes a light source 48, a plurality of key caps 24a that can emit light by light irradiated from the light source 48, a base plate 30 that supports the key caps 24a on the upper surface 30a side, and a membrane sheet 31 laminated on the upper surface 30a of the base plate 30. In the keyboard device 12C, the contact sheets 33, 34 and the spacer sheet 35 constituting the membrane sheet 31 are optically transparent, and a light reflecting layer 36 is provided on the upper surface 33a of the upper contact sheet 33. In the membrane sheet 31, at least one of the contact sheets 33, 34 and the spacer sheet 35 is disposed below the key caps 24a, and the membrane sheet 31 has a light diffusion pattern 42 on the surface thereof.

[0062] In such a keyboard device 12C, as shown in FIG. 6, the light L from the light source 48 is guided by the membrane sheet 31 and irradiated onto the keycaps 24a. In the keyboard device 12C, the upper surface 33a of the upper contact sheet 33 located at the top of the membrane sheet 31 is also covered with a light reflecting layer 36. Therefore, the light L introduced into the membrane sheet 31 is efficiently guided while being reflected and diffused within the membrane sheet 31 having optical transparency. The light L is diffused by the light diffusion pattern 42 provided on the membrane sheet 31 arranged below each keycap 24a, causing the keycaps 24a to emit light. As a result, in the keyboard device 12C, the light L introduced into the membrane sheet 31 is prevented from leaking and reducing the amount of light, and each keycap 24a can be illuminated with a sufficient amount of light.

[0063] In particular, in the keyboard device 12C, the light-emitting module 32A does not have the light-guiding member 44 and the reflective sheets 45 and 46. The light L is guided from the light source 48 to the keycap 24a only via the membrane sheet 31. In other words, the keyboard device 12C uses the membrane sheet 31 as a light-guiding member, and therefore does not need to install the light-guiding member 44 and the reflective sheets 45 and 46. Therefore, the keyboard device 12C can be significantly thinner than the above-mentioned keyboard devices 12A and 12B. Furthermore, the keyboard device 12C can reduce the number of parts by the amount of the light-guiding member 44, etc., and can also reduce product costs.

[0064] The keyboard device 10C can have a hole 52B that opens on the lower surface 34a of the membrane sheet 31 and penetrates the base plate 30. The light source 48 is inserted into the hole 52B. A lateral light irradiation surface 48a of the light source 48 faces the inner wall surface of the hole 52B formed in the membrane sheet 31. Therefore, the keyboard device 10C can reliably secure an incident surface for the light L from the light source 48 with respect to the membrane sheet 31 that acts as a light guiding member.

[0065] The hole 52B can penetrate the base plate 30, the lower contact sheet 34, and the spacer sheet 35, and the back can be closed by the upper contact sheet 33. The light irradiation surface 48a can face the end faces 34b, 35b of the lower contact sheet 34 and the spacer sheet 35 that form the inner wall surface of the hole 52B. This allows the membrane sheet 31 to sufficiently secure an incident surface for the light L from the light source 48, while preventing the light source 48 from being exposed above the keyboard device 12C, which would impair the appearance.

[0066] In the membrane sheet 31, the upper contact sheet 33, the lower contact sheet 34, and the spacer sheet 35 are arranged below the keycaps 24a, and the light diffusion pattern 42 can be provided on the surface of each of these sheets 33 to 35. In this way, the amount of light L diffused from the membrane sheet 31 to each keycap 24a can be sufficiently secured. In particular, the membrane sheet 31 has a three-layer structure. For this reason, if the light diffusion pattern 42 is provided only on the surface of the lower contact sheet 34, which is the bottom layer, it is difficult for the light L passing through the spacer sheet 35 and the upper contact sheet 33 above it to reach the keycap 24a. In this regard, by providing the light diffusion pattern 42 on all three layers, the amount of light L delivered to each keycap 24a can be increased.

[0067] As shown in FIG. 7, the light diffusion patterns 42 provided on the membrane sheet 31 arranged below the keycaps 24a can be arranged at different installation densities depending on the distance from the light source 48 to each keycap 24a. For example, in the configuration example shown in FIG. 7, seven light diffusion patterns 42 are arranged below the keycap 24a located to the left of the light source 48, and ten light diffusion patterns 42 are arranged below the keycap 24a located further to the left of this keycap 24a. In this way, the membrane sheet 31 can increase the installation density of the light diffusion patterns 42 below the keycaps 24a located farther from the light source 48 than the installation density below the keycaps 24a located closer to the light source 48. This allows the keycaps 24a located farther from the light source 48 to emit a sufficient amount of light.

[0068] Incidentally, in the keyboard device 12C, for example, the height of the light source 48 can be set to 0.4 mm, the thickness of the base plate 30 to 0.2 mm, the thickness of the contact sheets 33 and 34 to 0.07 mm, and the thickness of the spacer sheet 35 to 0.06 mm. The thickness of the flexible substrate 50 is, for example, 0.1 mm. Then, in the keyboard device 12C, the depth of the hole 52B is 0.33 mm, and the entire height of the light source 48 cannot be inserted into the hole 52B. Therefore, in the keyboard device 12C, in order to eliminate the difference (0.07 mm) between the height of the light source 48 and the depth of the hole 52B, for example, the thickness of the lower contact sheet 34 can be increased from 0.07 mm to 0.17 mm. Then, the light source 48 can be reliably inserted into the hole 52B, and the incidence surface of the light L on the membrane sheet 31 can be secured. That is, in the keyboard device 12C, the thickness of the lower contact sheet 34 can be made greater than the thickness of the upper contact sheet 33.

[0069] Another method for eliminating the above-mentioned difference (0.07 mm) is to change the thickness of the upper contact sheet 33 or the spacer sheet 35. However, if the upper contact sheet 33 is forcibly made thicker, its flexibility will be hindered, and there is a possibility that the smooth switching operation of the membrane sheet 31 will be hindered. If the thickness of the spacer sheet 35 is increased, the stroke required for switching the contact sheets 33, 34 will increase. Therefore, it is preferable to increase the thickness of the lower contact sheet 34 as described above.

[0070] As described above, the keyboard device 12C can guide light from the light source 48 to each keycap 24a using only the membrane sheet 31 instead of the light guide member 44 and the reflective sheets 45, 46. Here, the membrane sheet 31 has conductive patterns on the lower surface 33b of the upper contact sheet 33 and the upper surface 34c of the lower contact sheet 34. The spacer sheet 35 also has holes at various points for contacting the contact sheets 33, 34. Therefore, although all three layers of the membrane sheet 31 are optically transparent, there is a possibility that the amount of light may be reduced compared to a general light guide plate (light guide member 44).

[0071] The configuration in which the light diffusion patterns 42 are provided on the surfaces of the upper contact sheet 33, the lower contact sheet 34, and the spacer sheet 35 below the keycaps 24a is a configuration for further increasing the amount of light in such a keyboard device 12C. The same is true of the configuration in which the density of the light diffusion patterns 42 provided on the membrane sheet 31 is changed according to the distance from the light source 48. Other configuration examples that can further increase the amount of light in the keyboard device 12C will be described below with reference to Figs. 8 and 9.

[0072] Fig. 8 is a schematic cross-sectional side view of a light source 48 and its surroundings of a keyboard device 12C including a membrane sheet 31 having a bulging portion 60. In order to ensure ease of viewing of the drawing, Fig. 8 appropriately omits cross-sectional hatching of each component, and omits illustration of the light reflecting layer 36 and the decorative layer 37, and the same is true for Fig. 9.

[0073] The keyboard device 12C shown in FIG. 8 has a bulging portion 60 in a part of the membrane sheet 31. The bulging portion 60 is formed by bulging upward a portion forming the inner surface of the hole portion 52B of the upper contact sheet 33. The bulging height of the bulging portion 60 can be set to, for example, a height equal to or greater than the thickness of the upper contact sheet 33. In this way, when the vertical direction of the keyboard device 12C is taken as a reference, the upper surface 48c of the light source 48 can be set at a height position equal to or greater than the upper surface 33a of the upper contact sheet 33 excluding the bulging portion 60. Specifically, as shown in FIG. 8, the height H1 of the upper surface 48c of the light source 48 can be set at a height H2 of the upper surface 33a of the upper contact sheet 33. In FIG. 8, the height H1 and the height H2 are approximately the same height, but the height H1 can also be set at a position higher than the height H2.

[0074] Therefore, by providing the bulging portion 60, the keyboard device 12C can set the light irradiation surface 48a of the light source 48 at a height position facing the upper contact sheet 33. Therefore, in the keyboard device 12C, as shown in FIG. 8, the light L from the light source 48 is smoothly incident on the upper contact sheet 33 through the bulging portion 60 (see light L1 in FIG. 8). Therefore, the keyboard device 12C having the bulging portion 60 can further increase the amount of light L traveling straight through the upper contact sheet 33 and further increase the amount of light to each key cap 24a. In addition, by providing the bulging portion 60, the keyboard device 12C can also eliminate the difference between the height of the light source 48 and the depth of the hole portion 52B described above without making the thickness of the lower contact sheet 34 larger than the thickness of the upper contact sheet 33, for example.

[0075] FIG. 9 is a schematic cross-sectional side view of a light source 48 and its periphery of a keyboard device 12C that includes a membrane sheet 31 having a bent portion 62. As shown in FIG.

[0076] The keyboard device 12C shown in FIG. 9 has a bent portion 62 in a part of the membrane sheet 31. The bent portion 62 can be formed by bending downward a part of the spacer sheet 35 and the lower contact sheet 34 forming the inner wall surface of the hole portion 52B. The bent portion 62 is, for example, a part of the lower contact sheet 34 and the spacer sheet 35 bent downward in a crank shape over a predetermined distance from the end faces 34b, 35b. Reference numeral 30d in FIG. 9 denotes a double-sided tape for fixing and stabilizing the end of the bent portion 62 to the base plate 30. By having the bent portion 62, the membrane sheet 31 can form a gap G between the upper contact sheet 33 and the spacer sheet 35 and the lower contact sheet 34 bent at the bent portion 62. This allows the light irradiation surface 48a to face the bent portion 62 and the gap G.

[0077] Therefore, by providing the bending portion 62, the keyboard device 12C allows the light L from the light source 48 to be incident on the lower contact sheet 34 and the spacer sheet 35 from the end faces 34b, 35b of the bending portion 62. Furthermore, the light L passes through the gap G and is incident on the lower contact sheet 34 and the spacer sheet 35 from the inclined surface of the bending portion 62, and is reflected by the surface of the bending portion 62 (see light L2 in FIG. 9). The keyboard device 12C provided with this bending portion 62 can further increase the amount of light L passing through the lower contact sheet 34 and the spacer sheet 35, and further increase the amount of light reaching each keycap 24a. In FIG. 9, the bending portion 62 is used in combination with the bulging portion 60, but the bending portion 62 can also be applied to a configuration that does not have the bulging portion 60.

[0078] It should be noted that the present invention is not limited to the above-described embodiment, and can of course be freely modified without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0079] 10 Electronic equipment 12,12A~12C Keyboard device 14. Chassis 24a keycap 30 Base Plate 30c,38 through hole 31 Membrane Sheet 32,32A Light Emitting Module 33 Upper contact sheet 34 Lower contact sheet 35 Spacer sheet 36 Light reflective layer 40 Extension 42 Light diffusion pattern 44 Light guide member 48,48A light source 48a,48b Light irradiation surface 50 Flexible PCB 52,52A,52B Hole 60 Bulge 62 Bending section

Claims

1. A keyboard device comprising a light source and a plurality of key caps capable of emitting light by light emitted from the light source, A base plate that supports the key cap on an upper surface side; a membrane sheet having an upper contact sheet, a lower contact sheet, and a spacer sheet sandwiched between the upper contact sheet and the lower contact sheet, the membrane sheet being laminated on an upper surface of the base plate; Equipped with the upper contact sheet, the lower contact sheet, and the spacer sheet are optically transparent; A light reflecting layer is provided on the upper surface of the upper contact sheet, The membrane sheet has a portion of at least one of the upper contact sheet, the lower contact sheet, and the spacer sheet disposed below the keycap, and has a light diffusion pattern on the surface of the portion disposed below the keycap. A keyboard device comprising:

2. 2. The keyboard device according to claim 1, a hole portion that opens on a lower surface of the membrane sheet and penetrates the base plate; The light source is inserted into the hole, The light source has a light irradiation surface facing horizontally and facing the inner wall surface of the hole formed in the membrane sheet. A keyboard device characterized by:

3. 3. The keyboard device according to claim 2, the hole extends through the base plate, the lower contact sheet, and the spacer sheet; The inner part of the hole is closed by the upper contact sheet. A keyboard device comprising:

4. 4. The keyboard device according to claim 3, The light irradiation surface faces end surfaces of the lower contact sheet and the spacer sheet which form the inner wall surface of the hole. A keyboard device comprising:

5. 3. The keyboard device according to claim 2, A flexible substrate on which the light source is mounted is provided, The flexible substrate is laminated on the lower surface of the base plate. A keyboard device comprising:

6. The keyboard device according to any one of claims 2 to 5, The membrane sheet includes the upper contact sheet, the lower contact sheet, and the spacer sheet disposed below the keycap; The light diffusion patterns are provided on the surfaces of the upper contact sheet, the lower contact sheet, and the spacer sheet, which are disposed below the keycaps. A keyboard device comprising:

7. 4. The keyboard device according to claim 3, The thickness of the lower contact sheet is greater than the thickness of the upper contact sheet. A keyboard device comprising:

8. 4. The keyboard device according to claim 3, the upper contact sheet has a bulging portion in which a portion forming a back surface of the hole portion bulges upward, The light source has an upper portion inserted into the bulge, When the vertical direction of the keyboard device is taken as a reference, the upper surface of the light source is at a height position equal to or higher than the upper surface of the upper contact sheet excluding the bulging portion. A keyboard device comprising:

9. 8. The keyboard device according to claim 3 or 7, the membrane sheet has a bent portion that forms a gap between the spacer sheet and the upper contact sheet by bending downward a portion of the spacer sheet and the lower contact sheet that form an inner wall surface of the hole portion, The light emitting surface of the light source faces the bent portion. A keyboard device comprising:

10. 2. The keyboard device according to claim 1, a light guide member laminated on a lower surface side of the base plate, the membrane sheet has a through hole below the key cap through which the light guided by the light guide member passes to the key cap; At least one of the upper contact sheet, the lower contact sheet, and the spacer sheet of the membrane sheet has an extension portion extending to the inside of the through hole, and the light diffusion pattern is provided on the extension portion. A keyboard device comprising:

11. The keyboard device according to claim 10, a hole portion that penetrates the light guide member and the base plate and has a back surface formed by the membrane sheet; The light source is inserted into the hole. A keyboard device comprising:

12. The keyboard device according to claim 11, The light source is provided in plurality, Some of the plurality of light sources are inserted into the hole and have an upward light irradiation surface facing the innermost surface of the hole. A keyboard device comprising:

13. An electronic device, A housing and a keyboard device having a light source and a plurality of key caps capable of emitting light by the light emitted from the light source and facing an upper surface of the housing; Equipped with The keyboard device includes: A base plate that supports the key cap on an upper surface side; a membrane sheet having an upper contact sheet, a lower contact sheet, and a spacer sheet sandwiched between the upper contact sheet and the lower contact sheet, the membrane sheet being laminated on an upper surface of the base plate; Equipped with the upper contact sheet, the lower contact sheet, and the spacer sheet are optically transparent; A light reflecting layer is provided on the upper surface of the upper contact sheet, The membrane sheet has a portion of at least one of the upper contact sheet, the lower contact sheet, and the spacer sheet disposed below the keycap, and has a light diffusion pattern on the surface of the portion disposed below the keycap.

1. An electronic device comprising:

14. The electronic device according to claim 13, the keyboard device includes a hole that opens on a lower surface of the membrane sheet and penetrates the base plate; The light source is inserted into the hole, The light source has a light irradiation surface facing horizontally and facing the inner wall surface of the hole formed in the membrane sheet.

1. An electronic device comprising:

15. 15. The electronic device according to claim 14, The membrane sheet includes the upper contact sheet, the lower contact sheet, and the spacer sheet disposed below the keycap; The light diffusion patterns are provided on the surfaces of the upper contact sheet, the lower contact sheet, and the spacer sheet, which are disposed below the keycaps.

1. An electronic device comprising:

16. The electronic device according to claim 13, a light guiding member laminated on a lower surface of the base plate, the membrane sheet has a through hole below the key cap through which the light guided by the light guide member passes to the key cap; At least one of the upper contact sheet, the lower contact sheet, and the spacer sheet of the membrane sheet has an extension portion extending to the inside of the through hole, and the light diffusion pattern is provided on the extension portion.

1. An electronic device comprising:

17. 17. The electronic device according to claim 16, a hole portion that penetrates the light guide member and the base plate and has a back surface formed by the membrane sheet; The light source is inserted into the hole.

1. An electronic device comprising:

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