Key structure and keyboard

Abstract

The present application relates to a key structure and a keyboard. The key structure comprises a key cap, a light emitting unit, and a light spreading sheet. The light spreading sheet is arranged between the light emitting unit and the key cap. Light emitted by the light emitting unit forms a light pattern on a first surface of the light spreading sheet after passing through the light spreading sheet. The light pattern comprises a first light spot, and a position of a normal projection of the first light spot on a projection plane parallel to the light spreading sheet is different from a position of a normal projection of the light emitting unit on the projection plane.

Description

TECHNICAL FIELD

[0001] The present application relates to a key structure and a keyboard, and more particularly to a light-emitting key structure and a keyboard. BACKGROUND

[0002] A keyboard is indispensable to the use of a computer. In order to make the keyboard visually beautiful and still be clearly seen by the user in an insufficiently light environment, there are many light-emitting keyboards on the market.

[0003] However, the positions of the legends of the keys of various languages are different, and the light source of the conventional light-emitting keyboard cannot provide good illumination for the keycaps of various languages. Therefore, there is a great need in the art for a key structure that can distribute the light emitted by the light source to the positions of the keycaps that may have legends. SUMMARY

[0004] The present application relates to a key structure and a keyboard, and more particularly to a light-emitting key structure and a keyboard.

[0005] According to an aspect of the present application, a key structure is provided, comprising:

[0006] a keycap;

[0007] a light-emitting unit; and

[0008] a light-diffusing sheet,

[0009] wherein the light-diffusing sheet is disposed between the light-emitting unit and the keycap, the light emitted by the light-emitting unit forms a light pattern on a first surface of the light-diffusing sheet after passing through the light-diffusing sheet, the light pattern comprises a first light point, and the orthographic projection position of the first light point on a projection plane parallel to the light-diffusing sheet is different from the orthographic projection position of the light-emitting unit on the projection plane.

[0010] As an optional technical solution, a bottom plate is further included, the bottom plate has a first opening, and the orthographic projection range of the first opening on the projection plane at least partially overlaps the orthographic projection range of the light-emitting unit on the projection plane.

[0011] As an optional technical solution, the orthographic projection range of the light-emitting unit on the projection plane at least partially overlaps the orthographic projection range of a first legend of the keycap on the projection plane, and the orthographic projection range of the first light point on the projection plane at least partially overlaps the orthographic projection range of a second legend of the keycap on the projection plane.

[0012] As an optional technical solution, the bottom plate further includes a second opening, and the orthographic projection range of the second opening on the projection plane at least partially overlaps the orthographic projection range of the first light point on the projection plane.

[0013] As an optional technical solution, the light emitted by the light-emitting unit forms an inner projection on the second surface of the light-expanding sheet when the light enters the light-expanding sheet. The light pattern further includes a second light point different from the first light point. The orthographic projection of the first light point and the second light point different from the first light point on the projection plane surrounds the orthographic projection of the inner projection on the projection plane.

[0014] As an optional technical solution, the orthographic projection range of the inner projection on the projection plane at least partially overlaps with the orthographic projection range of the first legend of the keycap on the projection plane. The orthographic projection range of the first light point on the projection plane at least partially overlaps with the orthographic projection range of the second legend of the keycap on the projection plane.

[0015] As an optional technical solution, a thin film circuit board and at least one keyboard assembly between the thin film circuit board and the keycap are further included. The light-expanding sheet is arranged between the thin film circuit board and the keycap. The at least one keyboard assembly between the thin film circuit board and the keycap has a trigger part. The light-expanding sheet has a third opening. The third opening of the light-expanding sheet is located on the thin film circuit corresponding to the position of the trigger part.

[0016] As an optional technical solution, the light pattern includes a second light point. The orthographic projection position of the second light point on the projection plane is different from the orthographic projection position of the first light point on the projection plane.

[0017] As an optional technical solution, the orthographic projection size and / or shape of the second light point on the projection plane is different from the orthographic projection size and / or shape of the first light point on the projection plane.

[0018] As an optional technical solution, the light-expanding sheet includes a plurality of light-expanding films stacked with each other. The plurality of light-expanding films includes a first light-expanding film and a second light-expanding film. The first light-expanding film has microstructures protruding towards a first direction. The second light-expanding film has microstructures protruding towards the first direction.

[0019] As an optional technical solution, the light-expanding sheet includes a plurality of light-expanding films stacked with each other. The plurality of light-expanding films includes a first light-expanding film and a second light-expanding film. The first light-expanding film has microstructures protruding towards a first direction. The second light-expanding film has microstructures protruding towards a second direction opposite to the first direction.

[0020] As an optional technical solution, the ratio of the distance between the center of the length of the light pattern on the cross section transversely crossing the key structure and the center of the length of the legend of the keycap on the cross section to the length of the length of the light pattern on the cross section is 1 / 2.

[0021] As an optional technical solution, on the section, the ratio of the vertical distance from the light-emitting unit to the first surface of the light-expanding sheet to the length of the amplitude of the light pattern on the section is between 1 / 8 and 19 / 40.

[0022] As an optional technical solution, the light-expanding sheet has a printing part that partially covers the light pattern.

[0023] According to another aspect of the present application, the present application further provides a key structure, comprising:

[0024] a key cap;

[0025] a light-emitting unit; and

[0026] a light-expanding sheet,

[0027] wherein the light-expanding sheet is arranged between the light-emitting unit and the key cap, the light emitted by the light-emitting unit forms a light pattern on a first surface of the light-expanding sheet after passing through the light-expanding sheet, and the orthographic projection of the light pattern on a projection plane parallel to the light-expanding sheet encloses the orthographic projection position of the light-emitting unit on the projection plane.

[0028] According to another aspect of the present application, the present application further provides a keyboard comprising a plurality of keys, each of the keys having the key structure described above.

[0029] In summary, the key structure of the present application distributes the light emitted by the light-emitting unit to each position on the key cap by the light-expanding sheet, so that the light of the light pattern can provide illumination for key legends of multiple different languages.

[0030] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments, but is not limited to the embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0031] FIG. 1A is a sectional view of a key structure of a first embodiment of the present application.

[0032] FIG. 1B is a sectional view of a key structure of a second embodiment of the present application.

[0033] FIG. 1C is a sectional view of a key structure of a third embodiment of the present application.

[0034] FIG. 1D is a sectional view of a key structure of a fourth embodiment of the present application.

[0035] FIG. 1E is a sectional view of a key structure of a fifth embodiment of the present application.

[0036] FIG. 2A is a schematic diagram of a light spreading sheet of an embodiment of the present application.

[0037] FIG. 2B is a schematic diagram of a light spreading sheet of an embodiment of the present application.

[0038] FIG. 3A is a schematic diagram of a light pattern of an embodiment of the present application.

[0039] FIG. 3B is a schematic diagram of a light pattern of an embodiment of the present application.

[0040] FIG. 4A is a schematic diagram of a light pattern and a position of a bottom plate hole of an embodiment of the present application.

[0041] FIG. 4B is a schematic diagram of a keycap legend and a position of a light pattern of an embodiment of the present application.

[0042] FIG. 5 is a schematic diagram of an inner side projection and a light pattern of an embodiment of the present application.

[0043] FIG. 6 is a schematic diagram of a key structure section of an embodiment of the present application, in which some elements are omitted.

[0044] FIG. 7 is a schematic diagram of a light spreading sheet and a printing part thereon of an embodiment of the present application.

[0045] FIG. 8 is a schematic diagram of a keyboard of an embodiment of the present application.

[0046] FIG. 9 is an exploded view of a key structure of a first embodiment of the present application.

[0047] FIG. 10 is a light path diagram of a second embodiment of the present application. DETAILED DESCRIPTION

[0048] Referring to FIG. 1A-FIG. 1EIn one embodiment of the present invention, the key structure 101 includes a keycap 130, a light-emitting unit 110, and a light-diffusing plate 140. Furthermore, the key structure 101 may selectively include other key components (e.g., a spring-loaded reset member 150, a scissor-switch mechanism 160, a thin-film circuit board 170, a first separator 191, a second separator 192, a printed circuit board 120, etc.). In other embodiments, the key structure disclosed in the present invention may not include one or more of the aforementioned key components, or may include other types of key components. The light-diffusing plate 140 is disposed between the light-emitting unit 110 and the keycap 130, and the light-diffusing plate 140 allows the light emitted by the light-emitting unit 110 to pass through the light-diffusing plate 140 and form a light pattern on one surface of the light-diffusing plate 140. The following is a combination of... FIG. 3A and FIG. 3B Some light patterns of the present invention are described, but it should be understood that these descriptions are merely illustrative and do not limit the light patterns of the present invention.

[0049] Please refer to the following first. FIG. 3A In some embodiments, the light emitted by the light-emitting unit 110 passes through the light-amplifying plate 140 and can form a light pattern 310 on the upper surface of the light-amplifying plate 140 (i.e., the surface closer to the keycap 130). For example... FIG. 3A As shown, the light pattern 310 includes a first light spot 311, a second light spot 312, a third light spot 313, a fourth light spot 314, a fifth light spot 315, and a sixth light spot 316, which are located at different positions. In this embodiment, the light spot can be a clustered area of ​​a circle, square, or other shape formed when light reaches the upper surface of the light diffuser 140 due to refraction, reflection, or other optical behaviors. The shapes and / or sizes of the light spots can be the same or different to meet design requirements. For example, a larger light spot can be placed in a position where the design needs to be emphasized to increase attention or to match the size of the illustration.

[0050] In this embodiment, the light-emitting unit projection 1101 is the orthographic projection of the light-emitting unit 110 on the projection plane of the parallel light-expanding sheet 140. The position of any one of the first light spot 311, the second light spot 312, the third light spot 313, the fourth light spot 314, the fifth light spot 315, and the sixth light spot 316 is different from the position of the light-emitting unit projection 1101. That is, on the projection plane of the parallel light-expanding sheet 140, the orthographic projection positions of the first light spot 311, the second light spot 312, the third light spot 313, the fourth light spot 314, the fifth light spot 315, and the sixth light spot 316 are all different from the position of the light-emitting unit projection 1101. Therefore, the light-emitting unit 110 is similar to being diffused into multiple different point light sources under the optical effect of the light-expanding sheet 140, so that the light emitted by the light-emitting unit 110 can be distributed to each position on the keycap 130. In addition, it can be noted that each light spot of the light pattern 310 surrounds the light-emitting unit projection 1101, in other words, the light-emitting unit projection 1101 is located in the inner periphery of the light pattern 310, and the light pattern 310 is located in the outer periphery of the light-emitting unit projection 1101.

[0051] Referring to FIG. 3B In some embodiments, the light emitted by the light-emitting unit 110 can form a light pattern 320 on the upper surface (i.e., the surface closer to the keycap 130) of the light-expanding sheet 140 after passing through the light-expanding sheet 140. In this embodiment, the light pattern 320 is a grid composed of multiple intersecting lines (for example, multiple pairs of hyperbolas); in other words, the light rays emitted by the light-emitting unit 110 form multiple light projection lines on the upper surface of the light-expanding sheet 140 under the optical effect (for example, guidance, refraction, reflection, and / or patterning) of the light-expanding sheet 140. As FIG. 3B shown, the light pattern 320 surrounds the light-emitting unit projection 1101, so that, in comparison, the light-emitting unit projection 1101 is located in the inner periphery of the light patterns 310 and 320, and the light patterns 310 and 320 are located in the outer periphery of the light-emitting unit projection 1101.

[0052] Referring to FIG. 1A In this embodiment, the light-expanding sheet 140 is arranged between the elastic return member 150 (for example, a rubber dome) and the keycap 130, but the present application is not limited thereto. For example, referring to FIG. 1B-FIG. 1E As FIG. 1B shown, in an embodiment, the light-expanding sheet 140 can be arranged between the elastic return member 150 and the thin film circuit board 170; as FIG. 1C shown, in an embodiment, the light-expanding sheet 140 can be arranged between the thin film circuit board 170 and the bottom plate 180; as FIG. 1D shown, in an embodiment, the light-expanding sheet 140 can be arranged between the bottom plate 180 and the first partition 191; as FIG. 1EAs shown, in one embodiment, the light-amplifying plate 140 may be disposed between the first separator 19 and the second separator 192. It is understood that when the light-amplifying plate 140 is disposed between the base plate 180 and the light-emitting unit 110, different embodiments may have different numbers of separators to adjust the distance between the light-amplifying plate 140 and the light-emitting unit 110.

[0053] See FIG. 2A and FIG. 2B ,like FIG. 2A As shown, in some embodiments, the light amplifying sheet 140 may consist of only a single light amplifying film having a microstructure 1401. In one embodiment, FIG. 2A The microstructure 1401 of the light amplifier 140 shown can be a hexagonal pyramid, thereby enabling the light emitted by the light-emitting unit 110 to form as shown in the diagram. FIG. 3A The illustrated light pattern 310 is, for example, a star-shaped light pattern with six light points. In other embodiments, such as... FIG. 2B As shown, the light-amplifying film 140 can be composed of a first light-amplifying film 141 and a second light-amplifying film 142. FIG. 2B In the illustrated embodiment, the first light-amplifying film 141 and the second light-amplifying film 142 each have microstructures on surfaces facing away from each other. However, the invention is not limited to this. In other embodiments, the second light-amplifying film 142 may have microstructures on the surface facing the first light-amplifying film 141 (i.e., the upper surface). In one embodiment, FIG. 2B The microstructures of the first light-amplifying film 141 and the second light-amplifying film 142 shown can be hexagonal pyramids, thereby enabling the light emitted by the light-emitting unit 110 to form as shown in the diagram. FIG. 3B The light pattern 320 shown is, for example, a mesh light pattern with several pairs of hyperbolic patterns. These hyperbolic patterns are curves with significantly higher brightness than the surrounding curves formed after the light emitted by the light-emitting unit 110 passes through the light diffuser 140.

[0054] See FIG. 4A In one embodiment, the base plate 180 has an opening 1801 (or first opening 1801) corresponding to the light-emitting unit 110, such as FIG. 4A As shown, the opening 1801 can overlap with the projection 1101 of the light-emitting unit. Therefore, in embodiments where the light-amplifying plate 140 is disposed above or below the base plate 180, the light emitted by the light-emitting unit 110 can directly pass through the base plate 180 to illuminate the patterns on the keycap 130. In one embodiment (e.g.) FIG. 1D and FIG. 1EIn the embodiment shown where the light-emitting plate is located below the base plate 180, the base plate 180 may also have multiple openings (such as openings 1802-1807) so that the light emitted by the light-emitting unit 110, after passing through the light-emitting plate 140, forms light spots of a light pattern (such as light spots 311-316) that can pass through the base plate 180 to illuminate the patterns on the keycap 130. For example, as FIG. 4A As shown, opening 1802 (or second opening 1802) may overlap with the first light spot 311, opening 1803 may overlap with the second light spot 312, opening 1804 may overlap with the third light spot 313, opening 1805 may overlap with the fourth light spot 314, opening 1806 may overlap with the fifth light spot 315, and opening 1807 may overlap with the sixth light spot 316. In this document, the technical description "A and B overlap" may mean that A and B's orthographic projections on a projection plane parallel to the light amplifier 140 partially or completely overlap each other. Furthermore, in embodiments where the light amplifier 140 provides a light pattern 320 and is disposed on a base plate 180, the base plate 180 may have a plurality of openings that substantially overlap with the outline of the light pattern 320, allowing light from the light pattern 320 to pass through the base plate to illuminate the pattern on the keycap 130.

[0055] See FIG. 4B In one embodiment, the projection 1101 of the light-emitting unit overlaps with the second pattern 132 of the keycap 130, and the first light spot 311 overlaps with the first pattern 131 of the keycap 130. Therefore, in one embodiment, the light emitted by the light-emitting unit 110 can illuminate the second pattern 132 of the keycap 130, and the light from the first light spot 311 can illuminate the first pattern 131 of the keycap 130. In other embodiments, light spots 312-316 can also illuminate other patterns (if any) on the keycap 130, thus providing illumination for key patterns in multiple different languages.

[0056] See FIG. 5 In some embodiments, when the light emitted by the light-emitting unit 110 enters the light-amplifying sheet 140, it can form an inner projection 500 on the lower surface of the light-amplifying sheet 140 (i.e., the surface closer to the light-emitting unit 110). For example... FIG. 5As shown, the light spots 311-316 of the light pattern 310 surround the periphery of the inner projection 500. In other words, the light spreading sheet 140 expands the inner projection 500 of the light emitted by the light emitting unit 110 outwards into the light spots 311-316 of the light pattern 310. It should be understood that in the embodiment where the light spreading sheet 140 provides the light pattern 320, the light pattern 320 also surrounds the periphery of the inner projection 500 (not shown). In order to trigger the thin film circuit board 170 to generate a key signal when the key is pressed, the key assembly (such as the elastic return member 150, the scissor leg 160, etc.) between the thin film circuit board 170 and the key cap 130 can have at least one trigger portion. In some embodiments (such as the embodiment shown in FIG. 1 where the light spreading sheet 140 is disposed between the thin film circuit board 170 and the key cap 130), the key assembly (such as the elastic return member 150, the scissor leg 160, etc.) between the thin film circuit board 170 and the key cap 130 can have at least one trigger portion. FIG. 1A-FIG. 1B As shown in the embodiment where the light spreading sheet 140 is disposed between the thin film circuit board 170 and the key cap 130, the light spreading sheet 140 can further include an opening 510 (or a third opening 510), and the opening 510 is positioned corresponding to the trigger portion on the key assembly between the thin film circuit board 170 and the key cap 130, so that the trigger portion on the key assembly can pass through the opening 510 to trigger the thin film circuit board 170. FIG. 5 As shown in the embodiment where the light spreading sheet 140 is disposed between the thin film circuit board 170 and the key cap 130, the light spreading sheet 140 can further include an opening 510 (or a third opening 510), and the opening 510 is positioned corresponding to the trigger portion on the key assembly between the thin film circuit board 170 and the key cap 130, so that the trigger portion on the key assembly can pass through the opening 510 to trigger the thin film circuit board 170.

[0057] In some embodiments, the structure of the light spreading sheet 140 can be adjusted based on optical principles, so that the light spots of the light pattern (such as the light pattern 310) formed thereby have different sizes and / or shapes from each other. In addition, by providing the opening on the light spreading sheet 140, the number of light spots can also be adjusted by changing the size, number and position of the opening.

[0058] Referring to FIG. 6, FIG. 6 the length A can represent the length of the light pattern (such as the light pattern 310 or 320) formed by the light spreading sheet 140 in a cross section of the key structure; the distance B can represent the distance between the center of the legend 131 of the key cap 130 and the center of the light pattern (such as the light pattern 310 or 320) in the cross section of the key structure; the thickness C can represent the thickness of the light spreading sheet 140; and the distance E can represent the vertical distance from the light emitting unit 110 to the surface of the light pattern formed by the light spreading sheet 140 in the cross section of the key structure. In some embodiments, the ratio of the distance B to the length A can be 1 / 2; the ratio of the distance E to the length A can fall within the range of 1 / 8 to 19 / 40; and the thickness C can be 0.07-0.08 mm. In addition, in some embodiments, the number of microstructures (such as the microstructure 1401) on a single light spreading film (such as the first light spreading film 141 or the second light spreading film 142) of the light spreading sheet 140 can be 400-500.

[0059] Referring to FIG. 6, FIG. 7In some embodiments, the light spreading sheet 140 can have a printed portion 142. For example, to cover the light in certain positions of the light pattern formed by the light spreading sheet 140 to match the legend of certain languages, the printed portion 142 (e.g., by white printing) can be formed on the light spreading sheet 140 to cover the light in certain positions.

[0060] The key structure disclosed in the embodiments of the present application can be used to provide a keyboard that can emit light corresponding to legends of multiple languages and has low halo. For example, referring to FIG. 8 , the keyboard 800 can be a keyboard made using various key structures disclosed in the embodiments herein.

[0061] Referring to FIG. 9 In some embodiments, the bottom plate 180 can have multiple openings (e.g., openings 1801, 1808-1815, and have multiple clamps movably engaged with the scissors legs 160), and the light emitted by the light emitting unit 110 can pass through the openings on the bottom plate 180 to reach the thin film circuit board 170. As shown in FIG. 9 , the thin film circuit board 170 also has multiple openings (e.g., openings 171-174, for the clamps disposed in, for example, openings 1808, 1809, 1813, 1814 to pass through). The light emitted by the light emitting unit 110 can pass through the thin film circuit board 170 to reach the light spreading sheet 140, and after forming a light pattern (e.g., light pattern 310) on the light spreading sheet 140, provide illumination for the legends (e.g., first legend 131 and second legend 132) on the keycap 130. As shown in FIG. 9 , the openings on the bottom plate 180 can at least partially overlap the light pattern formed by the light spreading sheet 140, and in some embodiments, the light spreading sheet 140 can have openings 1402 for the light emitted by the light emitting unit 110 to pass through FIG. 9 , which is only an example and does not limit the position of the openings 1402 on the light spreading sheet 140. It should be understood that FIG. 9 , the size, position, number, and shape of the openings shown in FIG. 10 , some key assembly components (e.g., first divider 191 and second divider 192) are omitted for ease of viewing and illustration

[0062] Referring to FIG. 10 , FIG. 10 , the arrows in FIG. 10 , the light emitted by the light emitting unit 110 can pass through the openings (e.g., but not limited to opening 1801) of the bottom plate 180 and the thin film circuit board 170 ​The light emitted by the light-emitting unit (not shown) enters the light-expanding sheet 140 from the lower surface of the light-expanding sheet 140 (and forms the inner side projection 500), and forms a light pattern (such as the light pattern 310 or 320) on the upper surface of the light-expanding sheet 140, thereby providing illumination for the legends (such as the first legend 131, the second legend 132, and the third legend 133) at various positions on the keycap 130.

[0063] In summary, the key structure of the present application distributes the light emitted by the light-emitting unit to various positions on the keycap by the light-expanding sheet, which forms a light pattern on a surface of the light-expanding sheet after the light emitted by the light-emitting unit passes through the light-expanding sheet. In this way, the light of the light pattern can provide illumination for the legends of the keys in various languages.

[0064] The above description is only the preferred embodiments of the present application, and any equivalent changes and modifications made within the scope of the present application should be included in the scope of the present application.

Claims

1. A key structure characterized by comprising: A keycap; A light-emitting unit; and A light-expanding sheet, wherein the light-expanding sheet is disposed between the light-emitting unit and the keycap, light emitted by the light-emitting unit forms a light pattern on a first surface of the light-expanding sheet after passing through the light-expanding sheet, the light pattern comprises a first light point, and a position of a normal projection of the first light point on a projection plane parallel to the light-expanding sheet is different from a position of a normal projection of the light-emitting unit on the projection plane; wherein a range of the normal projection of the light-emitting unit on the projection plane at least partially overlaps with a range of a normal projection of a first legend of the keycap on the projection plane, and a range of the normal projection of the first light point on the projection plane at least partially overlaps with a range of a normal projection of a second legend of the keycap on the projection plane. Further comprising a backboard having a first opening, a range of a normal projection of the first opening on the projection plane at least partially overlaps with a range of the normal projection of the light-emitting unit on the projection plane.

2. The key structure according to claim 1, wherein The backboard further comprises a second opening, a range of a normal projection of the second opening on the projection plane at least partially overlaps with a range of the normal projection of the first light point on the projection plane.

3. The key structure according to claim 2, wherein A keycap; 4. A key structure characterized by comprising: A light-emitting unit; and A light-expanding sheet, wherein the light-expanding sheet is disposed between the light-emitting unit and the keycap, light emitted by the light-emitting unit forms a light pattern on a first surface of the light-expanding sheet after passing through the light-expanding sheet, the light pattern comprises a first light point, and a position of a normal projection of the first light point on a projection plane parallel to the light-expanding sheet is different from a position of a normal projection of the light-emitting unit on the projection plane; The light emitted by the light-emitting unit forms an inside projection on a second surface of the light-expanding sheet when entering the light-expanding sheet, the light pattern further comprises a second light point different from the first light point, and the normal projection of the first light point and the second light point different from the first light point on the projection plane surrounds a periphery of a range of the normal projection of the inside projection on the projection plane. The range of the normal projection of the inside projection on the projection plane at least partially overlaps with a range of a normal projection of a first legend of the keycap on the projection plane, and the range of the normal projection of the first light point on the projection plane at least partially overlaps with a range of a normal projection of a second legend of the keycap on the projection plane. Further comprising a thin film circuit board and at least one keyboard assembly between the thin film circuit board and the keycap, wherein the light-expanding sheet is disposed between the thin film circuit board and the keycap, the at least one keyboard assembly between the thin film circuit board and the keycap has a trigger part, the light-expanding sheet has a third opening, and the third opening of the light-expanding sheet is located on the thin film circuit at a position corresponding to the trigger part.

5. The key structure according to claim 4, wherein The light pattern comprises a second light point, and a position of a normal projection of the second light point on the projection plane is different from a position of a normal projection of the first light point on the projection plane.

6. The key structure according to claim 1 or 4, wherein A size and / or shape of the normal projection of the second light point on the projection plane is different from a size and / or shape of the normal projection of the first light point on the projection plane.

7. The key structure according to claim 1, wherein The light-expanding sheet comprises a plurality of light-expanding films stacked with each other, the plurality of light-expanding films comprises a first light-expanding film and a second light-expanding film, the first light-expanding film has microstructures protruding towards a first direction, and the second light-expanding film has microstructures protruding towards the first direction.

8. The key structure according to claim 7, wherein ​ 9. The key structure according to claim 1 or 4, wherein ​ 10. The key structure according to claim 1 or 4, wherein The light-expanding sheet comprises a plurality of light-expanding films stacked with each other, the plurality of light-expanding films comprising a first light-expanding film having microstructures protruding toward a first direction and a second light-expanding film having microstructures protruding toward a second direction opposite to the first direction.

11. The key structure according to claim 1 or 4, wherein A ratio of a distance between a center of a length of the light pattern on a cross section transverse to the key structure and a center of a length of a legend of the keycap on the cross section and a length of the light pattern on the cross section is 1 / 2.

12. The key structure according to claim 11, wherein On the cross section, a ratio of a vertical distance from the light-emitting unit to the first surface of the light-expanding sheet and the length of the light pattern on the cross section is between 1 / 8 and 19 / 40.

13. The key structure according to claim 1 or 4, wherein The light-expanding sheet has a printing portion partially covering the light pattern.

14. A key structure characterized by comprising: Comprise: a keycap; a light-emitting unit; and a light-expanding sheet, wherein the light-expanding sheet is disposed between the light-emitting unit and the keycap, light emitted by the light-emitting unit forms a light pattern on a first surface of the light-expanding sheet after passing through the light-expanding sheet, a normal projection of the light pattern on a projection plane parallel to the light-expanding sheet encloses a normal projection position of the light-emitting unit on the projection plane; wherein a normal projection range of the light-emitting unit on the projection plane at least partially overlaps a normal projection range of a first legend of the keycap on the projection plane, and a normal projection range of the light pattern on the projection plane at least partially overlaps a normal projection range of a second legend of the keycap on the projection plane.

15. A key structure characterized by comprising: Comprise: a keycap; a light-emitting unit; and a light-expanding sheet, wherein the light-expanding sheet is disposed between the light-emitting unit and the keycap, light emitted by the light-emitting unit forms a light pattern on a first surface of the light-expanding sheet after passing through the light-expanding sheet, a normal projection of the light pattern on a projection plane parallel to the light-expanding sheet encloses a normal projection position of the light-emitting unit on the projection plane; wherein light emitted by the light-emitting unit forms an inside projection on a second surface of the light-expanding sheet when entering the light-expanding sheet, a normal projection of the light pattern on the projection plane surrounds an outside of a normal projection range of the inside projection on the projection plane.

16. A keyboard comprising a plurality of keys, wherein Each of the keys has the key structure as claimed in any one of claims 1 to 15.

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