Keyboard device and electronic device

Abstract

To prevent reduction of the amount of light.SOLUTION: A keyboard device comprises a light source and a plurality of key caps which can emit light by light irradiated from the light source. The keyboard device comprises: a base plate supporting the key caps on the upper surface side; and a membrane sheet which has an upper contact sheet, a lower contact sheet, and a spacer sheet interposed between the upper contact sheet and the lower contact sheet and is laminated on an upper surface of the base plate. The upper contact sheet, the lower contact sheet, and the spacer sheet are light-transmissive. A light reflecting layer is provided on the upper surface of the upper contact sheet. A part of at least one of the upper contact sheet, the lower contact sheet, and the spacer sheet of the membrane sheet is arranged below the key caps, and a surface of the part arranged below the key caps is provided with a light diffusing pattern.SELECTED DRAWING: Figure 2

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 that can emit light from keycaps (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] Such keyboard devices often have a structure 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 located near the center of the keyboard device. Light from the light source is guided to the left and right by a light guide plate, and illuminates each keycap through through-holes formed in the base plate and membrane sheet.

[0005] Generally, each layer of the membrane sheet is made of transparent PET film. We conducted a light emission experiment in a darkroom on this keyboard device. We found that light was leaking into the membrane sheet from the through-holes under the keycaps, which reduced the amount of light irradiated onto the keycaps.

[0006] The present invention has been made in consideration of the above-mentioned problems of the conventional technology, 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 using light irradiated from the light source, and comprising: a base plate supporting the keycaps on their upper surfaces; and a membrane sheet having an upper contact sheet, a lower contact sheet, and a spacer sheet sandwiched between the upper and lower contact sheets, 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-diffusing 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 the upper surface of the housing, the keyboard device having a housing, a light source, and a plurality of keycaps capable of emitting light using 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, and 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-diffusing pattern on the surface of the portion arranged below the keycaps. [Effects of the Invention]

[0009] According to the above aspect of the present invention, it is possible to suppress a decrease in the amount of light. [Brief explanation of the drawings]

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

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A keyboard device and an electronic device including the same according to preferred embodiments of the present invention will be described in detail below 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 notebook PC in which housing 14 and display housing 18 are connected by a hinge 20 so that they can rotate relative to each other. 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, as long as it is an electronic device equipped with a keyboard device.

[0014] Below, the housing 14 and each element such as the keyboard device 12 mounted thereon 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 up and down, and the width direction being 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 its front surface. The display 16 is made of, for example, an organic EL display or a liquid crystal display. The bottom 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, 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 the 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 the periphery of key caps 24a, which serve as the operating surfaces of the key switches 24, is partitioned by a frame 26.

[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 molded integrally with the cover member 27 that forms the top surface 14a. The frame 26 may also 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 that they can move up and down. The key holes 26a are defined by a portion of the frame 26 surrounded by a horizontal frame portion 26b extending in the left-right direction and a vertical frame portion 26c extending in the front-to-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 surrounding area of ​​the keyboard device 12A according to the first embodiment. The frame 26 is omitted from 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 surrounding area 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 keycap 24a and a guide mechanism 24b. The guide mechanism 24b is a scissor mechanism that supports the keycap 24a on the upper surface 30a of the base plate 30 so that the keycap 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 keycap 24a is pressed down, and returns the keycap 24a to its original position when the keycap 24a is released from the pressed state.

[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 bent or 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 that overlaps 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 and 34.

[0026] The contact sheets 33, 34 have predetermined conductive patterns on 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 conductive ink such as silver paste or carbon paste on the surface of a transparent PET film. The contact sheets 33, 34 are formed from a transparent PET film, which makes them optically transparent in the surface direction and in the thickness direction perpendicular to the surface direction. The contact sheets 33, 34 may also be formed from materials other than transparent PET film, as long as they are optically transparent. The contact sheets 33, 34 are formed extremely thin, for example, about 0.07 mm, and are highly flexible.

[0027] The spacer sheet 35 provides insulation between the contact sheets 33 and 34. The spacer sheet 35 can be made of, for example, a transparent PET film, like the contact sheets 33 and 34, and is optically transparent. The spacer sheet 35 may also be made of a material other than a transparent PET film, as long as it is optically transparent. The thickness of the spacer sheet 35 can be, 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 by covering the upper surface 33a with light-reflective paint, for example, white or silver. The light-reflecting layer 36 is intended to efficiently guide light entering the membrane sheet 31 from the light-emitting module 32 within the membrane sheet 31. As shown in the configuration examples of FIGS. 5 and 6 described below, light from a light source 48 may be intentionally introduced into the membrane sheet 31. Light diffused by the light-diffusing pattern 42 may also be unintentionally introduced into the membrane sheet 31. Light diffused by the light-diffusing pattern 42 and further reflected by the keycaps 24a and guide mechanisms 24b may also be unintentionally introduced into the membrane sheet 31. The light-reflecting layer 36 also serves to prevent 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 from being visible through the gaps between the keycaps 24a and the frame 26. 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 keycap 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 key type.

[0030] As shown in FIGS. 2 and 3 , in this embodiment, the membrane sheet 31 has through-holes 38 directly below each keycap 24a. The through-holes 38 are, for example, substantially rectangular in plan view. The base plate 30 is arranged in a bridge-like configuration inside the through-holes 38, and the membrane sheet 31 is also arranged on the upper surface 30a of this portion in a floating island-like configuration. The through-holes 38 allow light from the light-emitting modules 32 to pass through to the keycaps 24a. The through-holes 38 are 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 the portion located below each key switch 24. Each hook 39 supports a pivot pin of the guide mechanism 24b. The base plate 30 has through-holes 30c. The through-holes 30c communicate with the through-holes 38 and allow light from the light-emitting modules 32 to pass through the through-holes 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 into the through-hole 38 .

[0032] The extension portion 40 is a small piece of the transparent PET film that forms the upper contact sheet 33 and protrudes into the inner space of the through-hole 38. The extension portion 40 is disposed below the keycap 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 of the contact sheets 33, 34 and the spacer sheet 35. The extension portion 40 can be formed to protrude rearward from the front inner wall of the through-hole 38, for example (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 and left and right inner walls of the through-hole 38.

[0033] A light diffusion pattern 42 is provided on the surface of the extension portion 40. The light diffusion pattern 42 can be provided on the lower surface 33b of the upper contact sheet 33 that forms the extension portion 40. The light diffusion pattern 42 can be provided on the upper surface of the upper contact sheet 33 that forms the extension portion 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 diffuses and reflects light guided within the upper contact sheet 33, thereby increasing the amount of light directed toward the keycap 24a. The light diffusion pattern 42 can be formed, for example, as a striped slit pattern as shown in FIG. 3. The light diffusion pattern 42 can also be formed as a circular or rectangular dot pattern as shown in FIG. 7. This allows the extension portion 40 to illuminate the keycap 24a with 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 stacked 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 can be made of a sheet made of a translucent resin such as PET, polycarbonate, or acrylic. The light guide member 44 guides light emitted from the light source 48. The light guide member 44 and the reflective sheets 45, 46 extend to overlap below all of the key switches 24. The light guide member 44 has a light diffusion pattern 42 on the surface of a portion located below each keycap 24a. The light diffusion pattern 42 can be provided on the lower surface 44a of the light guide member 44, which is located directly below the through-hole 30c. The light diffusion pattern 42 can be provided on the upper surface of the light guide member 44, or on both the upper and lower surfaces.

[0036] The upper reflective sheet 45 is laminated on the upper surface of the light-guiding member 44. The lower reflective sheet 46 is laminated on the lower surface of the light-guiding member 44. The reflective sheets 45, 46 cover the surface of the light-guiding member 44 to suppress light leakage from the light-guiding member 44, and maintain the amount of light inside the light-guiding member 44 by applying a white coating to the surfaces that contact the light-guiding member 44. The reflective sheets 45, 46 can be made of a resin sheet with high reflective performance, such as PET, polyester, or polyolefin. The upper reflective sheet 45 is cut out at a position that overlaps the through-hole 30c vertically. This allows the light-guiding member 44 to allow light diffused by the light diffusion pattern 42 to pass through the through-holes 30c, 38, causing the keycap 24a to emit light.

[0037] The light source 48 can be configured, for example, by 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-guiding 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 printed circuit (FPC) 50. The flexible substrate 50 is arranged along the lower surface of the lower reflective 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 whose inner surface is covered by the upper reflective sheet 45. The light source 48 is inserted into the hole 52 and can emit light sideways from light-emitting surfaces 48a provided on the left and right sides. The light emitted from the light source 48 is guided left and right by the light-guiding member 44 and can illuminate each keycap 24a from the backside.

[0039] 4 denotes mounting holes formed through appropriate locations of 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 this embodiment includes a light source 48, a plurality of keycaps 24a that can emit light using light irradiated from the light source 48, a base plate 30 that supports the keycaps 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 12A, the contact sheets 33, 34 and the spacer sheet 35 that constitute 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, a portion (extension 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 arranged below the keycaps 24a, and the extension 40 has a light diffusion pattern 42 on the surface of the extension 40.

[0041] In this keyboard device 12A, as shown in FIG. 2, light L irradiated from the light source 48 onto the keycaps 24a enters the membrane sheet 31 from an end surface partially exposed through the through-holes 38. In the keyboard device 12A, the upper surface 33a of the upper contact sheet 33, which is 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 within the optically transparent membrane sheet 31. The light L is diffused by the light-diffusing pattern 42 provided on the extension portion 40, causing the keycaps 24a to emit light. As a result, the keyboard device 12A prevents the light L introduced into the membrane sheet 31 from leaking and reducing the light intensity, allowing each keycap 24a to emit a sufficient amount of light. The white arrow L in Figure 2 mainly indicates light guided within the light-guiding member 44 and the membrane sheet 31, and the dotted arrow L mainly indicates light diffused by the light diffusion pattern 42, and the same is true for Figure 5 and subsequent figures.

[0042] In particular, the top surface of the membrane sheet is exposed to the exterior of the keyboard device, and therefore has conventionally been covered with black paint (decorative layer 37). Therefore, when light is incident on a conventional membrane sheet, the black paint absorbs the light and reduces the light intensity, which can easily lead to a reduction in the amount of light emitted from the keycaps 24a. In this regard, the keyboard device 12A provides a light-reflecting layer 36 below the decorative layer 37, thereby preventing light from being reduced by absorption in the decorative layer 37 and enabling efficient light guidance within the membrane sheet 31.

[0043] The keyboard device 12A can include a light-guiding member 44 laminated on the lower surface 30b side of the base plate 30. The membrane sheet 31 has through-holes 38 below the keycaps 24a, through which light L guided by the light-guiding member 44 passes to the keycaps 24a. In the keyboard device 12A, most of the light L from the light source 48 is irradiated onto the keycaps 24a from the light diffusion pattern 42 provided on the light-guiding member 44. On the other hand, some of the light L diffused from the light-guiding 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 onto the keycaps 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 that includes 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 enters 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 the keycap 24a and its surroundings of the keyboard device 12B according to the second embodiment. In the keyboard device 12B according to the second embodiment, elements that have the same or similar functions and effects as those of the keyboard device 12A according to the first embodiment described above are designated by the same reference numerals and detailed descriptions thereof are 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 plurality of 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 a row in the front-to-rear direction. The light sources 48A of the keyboard device 12B are arranged, for example, at the positions indicated by the reference numeral "48" in FIG. 4 with the reference numeral "48A" in parentheses. For example, the light sources 48A may be obtained by replacing two of the six light sources 48 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 set as appropriate, for example, in order to control the amount of light guided by the light-guiding member 44 and the amount of light guided by the membrane sheet 31 to a predetermined ratio.

[0048] Light source 48A is configured, for example, by an LED, and is similar to other light sources 48 in that it is mounted on the upper surface of flexible substrate 50. Light source 48A differs from light source 48A in the light emission direction (the orientation of the light emission surface). 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 reflective sheet 46, the light guide member 44, the upper reflective sheet 45, and the base plate 30, and the inner surface is closed by the membrane sheet 31. When the light source 48A is inserted into the hole 52A, the upward-facing light irradiation surface 48b faces the lower surface of the membrane sheet 31. Therefore, more light emitted 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, light L emitted upward from the light source 48A is incident on the underside of the membrane sheet 31. In the keyboard device 12B, the upper surface 33a of the upper contact sheet 33, which is 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 into the membrane sheet 31 is efficiently guided while being reflected and diffused within the optically transparent membrane sheet 31. This light L is diffused by the light diffusion pattern 42 provided on the extension portion 40, causing the keycap 24a to emit light. Meanwhile, light L emitted from another light source 48 and guided by the light-guiding member 44 is irradiated from the light diffusion pattern 42 provided on the light-guiding member 44 to the keycap 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 intensity, allowing each keycap 24a to emit a sufficient amount of light. In the keyboard device 12B, the ratio of the light intensity introduced into the membrane sheet 31 and 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 viewed as a whole, the keycap 24a can be adjusted so that the amount of light passing through the membrane sheet 31 is 60% and the amount of light passing through the light guide member 44 is 40%. Therefore, the keyboard device 12B can be designed, for example, by making the light guide member 44 as thin as possible and using the membrane sheet 31 to compensate for the resulting lack of light intensity. This has the advantage of allowing the keyboard device 12B to be thinner overall. Furthermore, in the keyboard device 12B, if the thickness of the light guide member 44 is not changed, the number of light sources 48 and 48A and the current value can be reduced to reduce power consumption.

[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 keycap 24a and its surrounding area of ​​a keyboard device 12C according to a third embodiment. Fig. 7 is a schematic plan view of the keycap 24a and its surrounding area shown in Fig. 6. The rubber dome 24c is not shown in Fig. 7.

[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 through-holes 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 reflective sheet 45, or a lower reflective sheet 46. The light-emitting module 32A can be configured to essentially include 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. This keyboard device 12C is configured to guide light emitted from the light source 48 to each keycap 24a using only 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 sheet 56 covers punched holes and the like formed in the base plate 30. The sheet 56 can be formed from a sheet having light reflectivity similar to the reflective sheets 45 and 46 described above.

[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. The light source 48 is preferably 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, which form the inner wall surfaces of the hole 52B. This allows light L emitted laterally from the light irradiation surface 48b of the light source 48 to smoothly enter 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 has a light diffusion pattern 42 in the portion disposed below the keycap 24a.

[0059] The light diffusion pattern 42 can be provided on the surface of at least one of the contact sheets 33, 34 and the spacer sheet 35 located below the keycap 24a. When the light diffusion pattern 42 is provided on only a portion 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. This allows the keyboard device 12C to ensure a sufficient amount of light diffused from the membrane sheet 31 to the keycap 24a.

[0060] Note that the hooks 49 also need to penetrate the membrane sheet 31 in the keyboard device 12C. For this reason, small holes 58 for inserting the hooks 49 are formed in the membrane sheet 31 of the keyboard device 12C (see FIGS. 6 and 7). However, the holes 58 can hinder the guiding and diffusing of light in the membrane sheet 31. Therefore, it is preferable that the holes 58 be formed to the minimum size that surrounds each hook 49. It is preferable that the gap between the inner circumferential surface of the holes 58 and the hooks 49 be 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 keycaps 24a that can emit light using light irradiated from the light source 48, a base plate 30 that supports the keycaps 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 that constitute 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 arranged below the keycaps 24a, and this sheet has a light diffusion pattern 42 on its surface.

[0062] In this keyboard device 12C, as shown in FIG. 6, light L from a light source 48 is guided by a membrane sheet 31 and irradiated onto the keycaps 24a. In the keyboard device 12C, the upper surface 33a of the upper contact sheet 33, which is the topmost layer 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 optically transparent membrane sheet 31. The light L is diffused by a light-diffusing pattern 42 provided on the membrane sheet 31 located below each keycap 24a, causing the keycaps 24a to emit light. As a result, the keyboard device 12C prevents the light L introduced into the membrane sheet 31 from leaking and reducing the amount of light, allowing each keycap 24a to emit a sufficient amount of light.

[0063] In particular, in the keyboard device 12C, the light-emitting module 32A does not have a light-guiding member 44 and reflective sheets 45 and 46. Light L is guided from the light source 48 to the keycap 24a only via the membrane sheet 31. In other words, by using the membrane sheet 31 as a light-guiding member, the keyboard device 12C does not need to install the light-guiding member 44 and 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 horizontal 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, which acts as a light guide member.

[0065] The hole 52B can penetrate the base plate 30, the lower contact sheet 34, and the spacer sheet 35, and can be closed at the back 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, which form the inner wall surfaces 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 detract from the appearance.

[0066] The membrane sheet 31 has an upper contact sheet 33, a lower contact sheet 34, and a spacer sheet 35 arranged below the keycaps 24a, and a light diffusion pattern 42 can be provided on the surface of each of these sheets 33 to 35. This ensures a sufficient amount of light L diffused from the membrane sheet 31 to each keycap 24a. In particular, the membrane sheet 31 has a three-layer structure. For this reason, if the light diffusion pattern 42 were provided only on the surface of the lower contact sheet 34, which is the lowest layer, it would be difficult for the light L passing through the spacer sheet 35 and 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 reaching each keycap 24a can be increased.

[0067] As shown in FIG. 7, the density of the light diffusion patterns 42 provided on the membrane sheet 31 arranged below the keycaps 24a can be changed 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 density of the light diffusion patterns 42 below keycaps 24a that are farther from the light source 48 than the density below keycaps 24a that are closer to the light source 48. This allows keycaps 24a located farther from the light source 48 to emit a sufficient amount of light.

[0068] 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 each, 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. In this case, the depth of the hole 52B in the keyboard device 12C 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, to eliminate the difference (0.07 mm) between the height of the light source 48 and the depth of the hole 52B, the thickness of the lower contact sheet 34 can be increased from 0.07 mm to 0.17 mm, for example. This allows the light source 48 to be reliably inserted into the hole 52B and also ensures that the light L is incident on the membrane sheet 31. In other words, 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 possible 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 made too thick, its flexibility will be impaired, which may hinder the smooth switching operation of the membrane sheet 31. Increasing the thickness of the spacer sheet 35 increases the stroke required for switching the contact sheets 33 and 34. 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-guiding member 44 and the reflective sheets 45 and 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 in various locations for contacting the contact sheets 33 and 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 lower than that of a typical light guide plate (light-guiding 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 applies to the configuration in which the density of the light diffusion patterns 42 provided on the membrane sheet 31 is changed depending on 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 Figures 8 and 9.

[0072] Fig. 8 is a schematic side cross-sectional view of a light source 48 and its surroundings of a keyboard device 12C equipped with a membrane sheet 31 having a bulging portion 60. In Fig. 8, cross-sectional hatching of each component and illustration of the light reflecting layer 36 and decorative layer 37 are omitted as appropriate to ensure ease of viewing, and the same applies to Fig. 9.

[0073] The keyboard device 12C shown in FIG. 8 has a bulge 60 in a portion of the membrane sheet 31. The bulge 60 is formed by bulging upward a portion of the upper contact sheet 33 that forms the inner surface of the hole 52B. The bulge height of the bulge 60 can be set to, for example, equal to or greater than the thickness of the upper contact sheet 33. This allows the upper surface 48c of the light source 48 to be set at a height equal to or greater than the upper surface 33a of the upper contact sheet 33 excluding the bulge 60, based on the vertical direction of the keyboard device 12C. 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 equal to or greater than the 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 height higher than the height H2.

[0074] Therefore, by providing the bulge 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, light L from the light source 48 is smoothly incident on the upper contact sheet 33 via the bulge portion 60 (see light L1 in FIG. 8). Therefore, the keyboard device 12C having the bulge portion 60 can further increase the amount of light L traveling straight through the upper contact sheet 33, and can further increase the amount of light reaching each keycap 24a. In addition, by providing the bulge portion 60, the keyboard device 12C can also eliminate the difference in height between the light source 48 and the depth of the hole portion 52B described above, for example, without making the thickness of the lower contact sheet 34 greater than the thickness of the upper contact sheet 33.

[0075] FIG. 9 is a schematic cross-sectional side view of a light source 48 and its surroundings 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 portion of the spacer sheet 35 and the lower contact sheet 34 that form the inner wall surfaces of the hole portion 52B. The bent portion 62 is formed, for example, by bending downward a predetermined distance from the end faces 34b, 35b of the lower contact sheet 34 and the spacer sheet 35 in a crank-like shape. Reference numeral 30d in FIG. 9 denotes double-sided tape for fixing and stabilizing the end of the bent portion 62 to the base plate 30. The membrane sheet 31 has the bent portion 62, which allows a gap G to be formed between the upper contact sheet 33 and the spacer sheet 35 and 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 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 be freely modified without departing from the spirit of the present invention. [Explanation of symbols]

[0079] 10 Electronic equipment 12, 12A~12C keyboard device 14. Case 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 that can emit light by light emitted from the light source, a base plate that supports the keycap on its upper surface; 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 the 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 characterized by:

2. 2. The keyboard device according to claim 1, a hole portion that opens on the 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 laterally 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 penetrates 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 characterized by:

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

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

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 characterized by:

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 characterized by:

8. 4. The keyboard device according to claim 3, the upper contact sheet has a bulging portion in which a portion forming a deep surface of the hole portion bulges upward, The light source has an upper portion inserted into the bulge portion, When the keyboard device is based on a vertical direction, 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 characterized by:

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 characterized by:

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 keycap that allows light guided by the light-guiding member to pass through to the keycap; At least one of the upper contact sheet, the lower contact sheet, and the spacer sheet of the membrane sheet has an extension portion that extends to the inside of the through hole, and the light diffusion pattern is provided on the extension portion. A keyboard device characterized by:

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

12. 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 characterized by:

13. An electronic device, The housing and a keyboard device having a light source and a plurality of key caps that can emit light by the light emitted from the light source, the keyboard device facing the top surface of the housing; Equipped with The keyboard device a base plate that supports the keycap on its upper surface; 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 the 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. An electronic device characterized by:

14. 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 laterally and facing the inner wall surface of the hole formed in the membrane sheet. An electronic device characterized by:

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. An electronic device characterized by:

16. 14. The electronic device according to claim 13, a light guide member laminated on a lower surface of the base plate; the membrane sheet has a through-hole below the keycap that allows light guided by the light-guiding member to pass through to the keycap; At least one of the upper contact sheet, the lower contact sheet, and the spacer sheet of the membrane sheet has an extension portion that extends to the inside of the through hole, and the light diffusion pattern is provided on the extension portion. An electronic device characterized by:

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 rear surface formed by the membrane sheet; The light source is inserted into the hole. An electronic device characterized by:

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