Backlight device for a light-emitting keyboard

Abstract

The application discloses a backlight device for a light-emitting keyboard, which comprises a light guide plate, a long strip-shaped flexible circuit board, a plurality of first light-emitting elements, a plurality of second light-emitting elements and a plurality of third light-emitting elements. The light guide plate has a plurality of first through holes, a plurality of second through holes and a plurality of third through holes. The long strip-shaped flexible circuit board comprises a first long strip part, a second long strip part and a third long strip part. Each first light-emitting element is electrically connected to the first lower surface of the first long strip part and is arranged in the corresponding first through hole. Each second light-emitting element is electrically connected to the third lower surface of the third long strip part and is arranged in the corresponding second through hole. Each third light-emitting element is electrically connected to the second upper surface of the second long strip part and is arranged in the corresponding third through hole. The backlight device of the application not only has more uniform light emission, but also has the advantages of power saving, low cost and the like, especially the manufacturing cost of the flexible circuit board is low.

Description

Technical Field

[0001] This invention relates to a backlight device for an illuminated keyboard, and more particularly to a backlight device for an illuminated keyboard that has the advantages of being energy-saving and low-cost. Background Technology

[0002] Backlit keyboards are now common input peripherals on the market. Early backlighting devices for backlit keyboards arranged a considerable number of light-emitting elements (usually LEDs) along the longitudinal side (short side) of a light guide plate. However, due to the energy transfer of light within the light guide plate, energy attenuation is not linearly inversely proportional to the transmission distance; the farther the light travels, the greater the energy loss. Clearly, such prior art backlighting devices exhibit uneven light emission, with dark areas potentially occurring far from the light-emitting elements. Furthermore, such prior art backlighting devices are very power-intensive.

[0003] Please see Figure 1 , Figure 1 A top view schematic diagram of a prior art backlight device 1 is shown. The backlight device 1 includes a light guide plate 10, a flexible circuit board 12, and a plurality of light-emitting elements 14. The light guide plate 10 has a lateral side (long side) 101, a top surface 102, and a back surface opposite to the top surface 102 (not shown). Figure 1 The light guide plate 10 also has two opposing longitudinal sides (103, 104). The light guide plate 10 further has a plurality of through holes 106. Specifically, the plurality of through holes 106 are arranged approximately along the centerline of the vertical transverse side 101. Each through hole 106 has its own light-incident surface 108. The multiple light-incident surfaces 108 of the plurality of through holes 106 alternately face the two longitudinal sides (103, 104). Each light-emitting element 14 corresponds to one through hole 106. The plurality of light-emitting elements 14 are electrically bonded to a flexible circuit board 12. The flexible circuit board 12 is disposed on the back side of the light guide plate 10, such that each light-emitting element 14 is placed in its corresponding through hole 106. Each light-emitting element 14 is a side-emitting element. The light emitted by each light-emitting element 14 enters the light guide plate 10 from the light-incident surface 108 of its corresponding through hole 106, is transmitted within the light guide plate 10, and then exits from the top surface 102 of the light guide plate 10. In this way, the backlight device 1 of the prior art emits light evenly throughout, thereby avoiding dark areas. However, the power consumption of such prior art backlight devices 1 is still high. Figure 1 The number of light-emitting elements 14 shown is for illustrative purposes only and does not represent the actual number. Generally, the light-emitting elements 14 are light-emitting diodes (LEDs). Figure 1 The backlight device 1 shown is an example of an illuminated keyboard for a notebook computer, which uses 15 LEDs with a thickness of 0.4 mm.

[0004] Furthermore, there is significant room for reducing the manufacturing cost of the flexible circuit boards used in the aforementioned backlight devices.

[0005] Previous backlight devices primarily used light-emitting diodes (LEDs) as their light-emitting elements. With the miniaturization of LEDs, sub-millimeter LEDs (mini-LEDs) and micro LEDs (micro-LEDs) are now commercially available.

[0006] To reduce the power consumption of prior art backlighting devices, backlighting devices for backlit keyboards have employed a greater number of sub-millimeter LEDs. Each keycap on the backlit keyboard is equipped with at least one sub-millimeter LED. This results in more uniform illumination, eliminates dark areas, and reduces power consumption. For example, a backlighting device for a notebook computer's backlit keyboard uses 95 mini-LEDs. However, such prior art backlighting devices are relatively expensive. Summary of the Invention

[0007] In view of the problems in the prior art, the present invention provides a backlight device to solve the above-mentioned problems.

[0008] Therefore, the technical problem to be solved by the present invention is to provide a backlight device, the backlight device comprising:

[0009] A light guide plate defines a longitudinal direction and a transverse direction, and has a top surface, a back surface opposite to the top surface, a first transverse side, a second transverse side opposite to the first transverse side, a first longitudinal side, a second longitudinal side opposite to the first longitudinal side, a plurality of first through holes, a plurality of second through holes, and a plurality of third through holes. The plurality of first through holes are arranged from the first transverse side along the longitudinal direction and are close to the first longitudinal side. The plurality of second through holes are arranged from the first transverse side along the longitudinal direction and are close to the second longitudinal side. The plurality of third through holes are adjacent to the first transverse side. The second transverse side is arranged along the transverse direction and located between the plurality of first through holes and the plurality of second through holes. Each first through hole has its own first light-incident surface. The plurality of first light-incident surfaces corresponding to the plurality of first through holes alternately face the second longitudinal side and the first longitudinal side. Each second through hole has its own second light-incident surface. The plurality of second light-incident surfaces corresponding to the plurality of second through holes alternately face the first longitudinal side and the second longitudinal side. Each third through hole has its own third light-incident surface. The plurality of third light-incident surfaces corresponding to the plurality of third through holes face the first transverse side.

[0010] A long strip-shaped flexible circuit board includes a first long strip portion, a first bent portion connecting the first long strip portion, a second long strip portion connecting the first bent portion, a second bent portion connecting the second long strip portion, and a third long strip portion connecting the second bent portion. The first long strip portion has a first upper surface and a first lower surface and defines a first length direction. The second long strip portion has a second upper surface and a second lower surface and defines a second length direction. The third long strip portion has a third upper surface and a third lower surface and defines a third length direction.

[0011] A plurality of first light-emitting elements are electrically bonded to the first lower surface of the first elongated portion and arranged along the first length direction, and each first light-emitting element corresponds to a first through hole;

[0012] A plurality of second light-emitting elements are electrically bonded to the third lower surface of the third elongated portion and arranged along the third length direction, each second light-emitting element corresponding to a second through hole; and

[0013] Multiple third light-emitting elements are electrically bonded to the second upper surface of the second elongated portion and arranged along the second length direction, with each third light-emitting element corresponding to a third through hole;

[0014] The first and second bending portions are bent such that the first lower surface of the first elongated portion, the third lower surface of the third elongated portion, and the second upper surface of the second elongated portion are on the same plane. The elongated flexible circuit board is placed on the back side of the light guide plate with the first lower surface, the second upper surface, and the third lower surface, so that each first light-emitting element is placed in its corresponding first through hole, each second light-emitting element is placed in its corresponding second through hole, and each third light-emitting element is placed in its corresponding third through hole. Each first light-emitting element emits a first light beam that strikes the first light-incident surface of its corresponding first through hole and then enters the light guide plate. Each second light-emitting element emits a second light beam that strikes the second light-incident surface of its corresponding second through hole and then enters the light guide plate. Each third light-emitting element emits a third light beam that strikes the third light-incident surface of its corresponding third through hole and then enters the light guide plate.

[0015] As an optional technical solution, the first distance between the plurality of first through holes and the first longitudinal side and the second distance between the plurality of second through holes and the second longitudinal side are one-fifth to one-half of the lateral length of the first transverse side.

[0016] As an optional technical solution, the backlight device further includes a connecting flexible circuit board, which includes a third bent portion and a fourth elongated portion. The third bent portion is connected to the leading edge of the second elongated portion, and the fourth elongated portion is connected to the third bent portion. The third bent portion is bent so that a portion of the fourth elongated portion is in close contact with the second lower surface of the second elongated portion.

[0017] The present invention also provides a backlight device for an illuminated keyboard, the backlight device comprising:

[0018] A light guide plate defines a longitudinal direction and a transverse direction, and the light guide plate has a top surface, a back surface opposite to the top surface, a first transverse side, a second transverse side opposite to the first transverse side, a first longitudinal side, a second longitudinal side opposite to the first longitudinal side, a plurality of first through holes, a plurality of second through holes, and a plurality of third through holes. The plurality of first through holes are arranged from the first transverse side along the longitudinal direction and close to the first longitudinal side. The plurality of second through holes are arranged from the first transverse side along the longitudinal direction and close to the second longitudinal side. The plurality of third through holes are arranged along the transverse direction and positioned... Between the plurality of first through holes and the plurality of second through holes and near the second lateral side, each first through hole has its own first light-incident surface, and the plurality of first light-incident surfaces corresponding to the plurality of first through holes alternately face the second longitudinal side and the first longitudinal side. Each second through hole has its own second light-incident surface, and the plurality of second light-incident surfaces corresponding to the plurality of second through holes alternately face the first longitudinal side and the second longitudinal side. Each third through hole has its own third light-incident surface, and the plurality of third light-incident surfaces corresponding to the plurality of third through holes alternately face the first lateral side and the second lateral side.

[0019] A long strip-shaped flexible circuit board includes a first long strip portion, a first bent portion connecting the first long strip portion, a second long strip portion connecting the first bent portion, a second bent portion connecting the second long strip portion, and a third long strip portion connecting the second bent portion. The first long strip portion has a first upper surface and a first lower surface and defines a first length direction. The second long strip portion has a second upper surface and a second lower surface and defines a second length direction. The third long strip portion has a third upper surface and a third lower surface and defines a third length direction.

[0020] A plurality of first light-emitting elements are electrically bonded to the first lower surface of the first elongated portion and arranged along the first length direction, and each first light-emitting element corresponds to a first through hole;

[0021] A plurality of second light-emitting elements are electrically bonded to the third lower surface of the third elongated portion and arranged along the third length direction, each second light-emitting element corresponding to a second through hole; and

[0022] Multiple third light-emitting elements are electrically bonded to the second upper surface of the second elongated portion and arranged along the second length direction, with each third light-emitting element corresponding to a third through hole;

[0023] The first and second bending portions are bent such that the first lower surface of the first elongated portion, the third lower surface of the third elongated portion, and the second upper surface of the second elongated portion are on the same plane. The elongated flexible circuit board is placed on the back side of the light guide plate with the first lower surface, the second upper surface, and the third lower surface, so that each first light-emitting element is placed in its corresponding first through hole, each second light-emitting element is placed in its corresponding second through hole, and each third light-emitting element is placed in its corresponding third through hole. Each first light-emitting element emits a first light beam that strikes the first light-incident surface of its corresponding first through hole and then enters the light guide plate. Each second light-emitting element emits a second light beam that strikes the second light-incident surface of its corresponding second through hole and then enters the light guide plate. Each third light-emitting element emits a third light beam that strikes the third light-incident surface of its corresponding third through hole and then enters the light guide plate.

[0024] As an optional technical solution, the first light-incident surface of the first through hole closest to the second lateral side faces the first longitudinal side and is adjacent to the second lateral side; the third light-incident surface of the third through hole closest to the first longitudinal side faces the second lateral side and is adjacent to the first longitudinal side; the third light-incident surface of the third through hole closest to the second longitudinal side faces the second lateral side and is adjacent to the second longitudinal side; and the second light-incident surface of the second through hole closest to the second lateral side faces the second longitudinal side and is adjacent to the second lateral side.

[0025] As an optional technical solution, the first distance between the plurality of first through holes and the first longitudinal side and the second distance between the plurality of second through holes and the second longitudinal side are one-fifth to one-half of the lateral length of the first transverse side.

[0026] As an optional technical solution, the third distance between the plurality of third through holes and the second transverse side is one-fifth to one-half of the longitudinal length of the first longitudinal side.

[0027] As an optional technical solution, the backlight device further includes a connecting flexible circuit board, which includes a third bent portion and a fourth elongated portion. The third bent portion is connected to the leading edge of the second elongated portion, and the fourth elongated portion is connected to the third bent portion. The third bent portion is bent so that a portion of the fourth elongated portion is in close contact with the second lower surface of the second elongated portion.

[0028] The present invention also provides a backlight device for an illuminated keyboard, the backlight device comprising:

[0029] A light guide plate defines a longitudinal direction and a transverse direction, and the light guide plate has a top surface, a back surface opposite to the top surface, a first transverse side, a second transverse side opposite to the first transverse side, a first longitudinal side, a second longitudinal side opposite to the first longitudinal side, and a plurality of through holes. The plurality of through holes are arranged along the transverse direction and located between the first longitudinal side and the second longitudinal side. Each through hole has its own light-incident surface, and the plurality of light-incident surfaces corresponding to the plurality of through holes alternately face the first transverse side and the second transverse side.

[0030] A long, flexible circuit board having an upper surface and a lower surface and defining a length direction; and

[0031] Multiple light-emitting elements are electrically bonded to the upper surface of the long strip-shaped flexible circuit board and arranged along the length direction, with each first light-emitting element corresponding to a through hole;

[0032] The long, flexible circuit board is placed on the back of the light guide plate with its upper surface, so that each light-emitting element is placed in its corresponding through hole, and each light-emitting element emits light towards the light-incident surface of its corresponding through hole and then into the light guide plate.

[0033] As an optional technical solution, the distance between the plurality of through holes and the second lateral side is half the longitudinal length of the first longitudinal side; or, the backlight device further includes a connecting flexible circuit board, the connecting flexible circuit board including a bent portion and an elongated portion, the bent portion being connected to the leading edge of the elongated flexible circuit board, the elongated portion being connected to the bent portion, wherein the bent portion is bent so that a portion of the elongated portion is in close contact with the lower surface of the elongated flexible circuit board.

[0034] Compared with the prior art, the backlight device of the present invention not only emits light more uniformly, but also has the advantages of saving power and low cost, especially the low manufacturing cost of the flexible circuit board used.

[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention. Attached Figure Description

[0036] Figure 1 This is a top view of a prior art backlight device.

[0037] Figure 2 This is a top view schematic diagram of the backlight device according to a first preferred embodiment of the present invention.

[0038] Figure 3 for Figure 2 A cross-sectional view of the backlight device along line AA.

[0039] Figure 4 A top view of the backlight device of the first preferred embodiment of the present invention, showing an elongated flexible circuit board in an unbent state.

[0040] Figure 5 A top view of a backlight device, a necessary component of the first preferred embodiment of the present invention, a long strip of flexible circuit board in a bent state.

[0041] Figure 6 This is a top view schematic diagram of the backlight device according to a second preferred embodiment of the present invention.

[0042] Figure 7 for Figure 6 A cross-sectional view of the backlight device along line BB.

[0043] Figure 8 A top view of the backlight device of the second preferred embodiment of the present invention, showing an elongated flexible circuit board in an unbent state.

[0044] Figure 9 A top view of a backlight device, a necessary component of the second preferred embodiment of the present invention, showing a long strip of flexible circuit board in a bent state.

[0045] Figure 10 This is a top view schematic diagram of the backlight device according to a third preferred embodiment of the present invention.

[0046] Figure 11 for Figure 10 A cross-sectional view of the central backlight device along the CC line.

[0047] Figure 12 A top view of the backlight device of the third preferred embodiment of the present invention, showing an elongated flexible circuit board in an unbent state.

[0048] Figure 13 A top view of a necessary component of the backlight device in the third preferred embodiment of the present invention—a long strip of flexible circuit board in a bent state. Detailed Implementation

[0049] To provide a further understanding of the purpose, structure, features and functions of the present invention, detailed descriptions are provided below with reference to embodiments.

[0050] Please see Figure 2 , Figure 3 , Figure 4 and Figure 5The above figures schematically depict a backlight device according to a first preferred embodiment of the present invention. Figure 2 This is a top view schematic diagram of the backlight device according to a first preferred embodiment of the present invention; Figure 3 for Figure 2 A cross-sectional view of the central backlight device along line AA; Figure 4 A top view of the backlight device of the first preferred embodiment of the present invention, showing an essential component – ​​a long strip of flexible circuit board – in an unbent state. Figure 5 A top view of a backlight device, a necessary component of the first preferred embodiment of the present invention, a long strip of flexible circuit board in a bent state. Figure 4 In the present invention, the essential components of the light-emitting device 2 are a strip-shaped flexible circuit board 22, a plurality of first light-emitting elements 24, a plurality of second light-emitting elements 26 and a plurality of third light-emitting elements 28, and the strip-shaped flexible circuit board 22 is in an unbent state. Figure 5 In the backlight device 2, essential components include a strip-shaped flexible circuit board 22, multiple first light-emitting elements 24, multiple second light-emitting elements 26, and multiple third light-emitting elements 28, with the strip-shaped flexible circuit board 22 in a bent state. The backlight device 2 according to a first preferred embodiment of the present invention is used for a backlight keyboard.

[0051] like Figure 2 and Figure 3 As shown, the backlight device 2 according to a first preferred embodiment of the present invention includes a light guide plate 20, a strip-shaped flexible circuit board 22, a plurality of first light-emitting elements 24, a plurality of second light-emitting elements 26, and a plurality of third light-emitting elements 28.

[0052] The light guide plate 20 defines a longitudinal direction L and a transverse direction T. The light guide plate 20 has a top surface 201, a back surface 202 opposite to the top surface 201, a first transverse side 203, a second transverse side 204 opposite to the first transverse side 203, a first longitudinal side 205, a second longitudinal side 206 opposite to the first longitudinal side 205, a plurality of first through holes 207, a plurality of second through holes 208, and a plurality of third through holes 209. The plurality of first through holes 207 are arranged from the first transverse side 203 along the longitudinal direction L and are close to the first longitudinal side 205. The plurality of second through holes 208 are arranged from the first transverse side 203 along the longitudinal direction L and are close to the second longitudinal side 206. The plurality of third through holes 209 are adjacent to the second transverse side 204, arranged along the transverse direction T, and located between the plurality of first through holes 207 and the plurality of second through holes 208. Each first through hole 207 has its own first light-incident surface 2072. Multiple first through-holes 207 have multiple first light-incident surfaces 2072 that alternately face the second longitudinal side 206 and the first longitudinal side 205. Each second through-hole 208 has its own second light-incident surface 2082. The multiple second light-incident surfaces 2082 of the multiple second through-holes 208 alternately face the first longitudinal side 205 and the second longitudinal side 206. Each third through-hole 209 has its own third light-incident surface 2092. The multiple third light-incident surfaces 2092 of the multiple third through-holes 209 face the first transverse side 203.

[0053] like Figure 4 and Figure 5 As shown, the elongated flexible circuit board 22 includes a first elongated portion 221, a first bent portion 222 connecting the first elongated portion 221, a second elongated portion 223 connecting the first bent portion 222, a second bent portion 224 connecting the second elongated portion 223, and a third elongated portion 225 connecting the second bent portion 224. The first elongated portion 221 has a first upper surface 2212 and a first lower surface 2214, and defines a first length direction S1. The second elongated portion 223 has a second upper surface 2232 and a second lower surface 2234, and defines a second length direction S2. The third elongated portion 225 has a third upper surface 2252 and a third lower surface 2254, and defines a third length direction S3.

[0054] Similarly, Figure 4 and Figure 5As shown, a plurality of first light-emitting elements 24 are electrically bonded to the first lower surface 2214 of the first elongated portion 221 and arranged along the first length direction S1. Each first light-emitting element 24 corresponds to a first through-hole 207, and the light-emitting direction of each first light-emitting element 24 is the same as the orientation of the first light-incident surface 2072 of its corresponding first through-hole 207. A plurality of second light-emitting elements 26 are electrically bonded to the third lower surface 2254 of the third elongated portion 225 and arranged along the third length direction S3. Each second light-emitting element 26 corresponds to a second through-hole 208, and the light-emitting direction of each second light-emitting element 26 is the same as the orientation of the second light-incident surface 2082 of its corresponding third through-hole 208. A plurality of third light-emitting elements 28 are electrically bonded to the second upper surface 2232 of the second elongated portion 223 and arranged along the second length direction S2. Each third light-emitting element 28 corresponds to a third through-hole 209, and the light-emitting direction of each third light-emitting element 28 is the same as the orientation of the second light-incident surface 2092 of its corresponding second through-hole 209. By using light-emitting elements with different orientations and through holes with different orientations on the light guide plate, the backlight device of the present invention emits light more uniformly.

[0055] The first bend 222 and the second bend 224 are bent so that the first lower surface 2214 of the first elongated portion 221, the third lower surface 2254 of the third elongated portion 225, and the second upper surface 2232 of the second elongated portion 223 are coplanar. Figure 5 As shown, a long, strip-shaped flexible circuit board 22 is placed on the back surface 202 of the light guide plate 20 with its first lower surface 2214, second upper surface 2232, and third lower surface 2254, such that each first light-emitting element 24 is placed in its corresponding first through-hole 207, each second light-emitting element 26 is placed in its corresponding second through-hole 208, and each third light-emitting element 28 is placed in its corresponding third through-hole 209, as shown. Figure 2 As shown. It should be noted that, Figure 5 The top view of the elongated flexible circuit board 22 shows a U-shape. If the elongated flexible circuit board 22 is directly cut into a U-shape, the manufacturing process consumes a lot of materials and has extremely high manufacturing costs. Clearly, the backlight device 2 according to the first preferred embodiment of the present invention, by bending the first bending portion 222 and the second bending portion 224 to form the elongated flexible circuit board 22 that shows a U-shape in its top view, has lower manufacturing costs.

[0056] Each first light-emitting element 24 emits a first light beam that strikes the first light-incident surface 2072 of its corresponding first through-hole 207, and then enters the light guide plate 20. Each second light-emitting element 26 emits a second light beam that strikes the second light-incident surface 2082 of its corresponding second through-hole 208, and then enters the light guide plate 20. Each third light-emitting element 28 emits a third light beam that strikes the third light-incident surface 2092 of its corresponding third through-hole 209, and then enters the light guide plate 20. Thus, according to the first backlight device of the present invention, the use of a U-shaped elongated flexible circuit board combined with through-holes on the light guide plate with different orientations of the light-incident surfaces makes the backlight device emit light more uniformly and has advantages such as power saving and low cost.

[0057] In one specific embodiment, each of the first light-emitting element 24, each of the second light-emitting element 26, and each of the third light-emitting element 28 may be a light-emitting diode.

[0058] In one specific embodiment, similarly Figure 2 As shown, the first distance d1 between the plurality of first through holes 207 and the first longitudinal side 205 and the second distance d2 between the plurality of second through holes 208 and the second longitudinal side 206 are one-fifth to one-half of the lateral length X of the first transverse side 203.

[0059] For further information, please continue to refer to [the relevant resources / references]. Figure 4 and Figure 5 According to a first preferred embodiment of the present invention, the backlight device 2 further includes a connecting flexible circuit board 29. The connecting flexible circuit board 29 includes a third bent portion 291 and a fourth elongated portion 292. The third bent portion 291 is connected to the leading edge 2236 of the second elongated portion 223. The fourth elongated portion 292 is connected to the third bent portion 291. In practical applications, the third bent portion 291 is bent so that a portion of the fourth elongated portion 292 is in close contact with the second lower surface 2234 of the second elongated portion 223. It should be noted that the fourth elongated portion 292 of the backlight device 2 according to the first preferred embodiment of the present invention is also elongated, so that the connecting flexible circuit board 29 and the elongated flexible circuit board 22 are molded together, which can also achieve the purpose of low material consumption, thereby reducing the manufacturing cost of the connecting flexible circuit board 29 and the elongated flexible circuit board 22.

[0060] Please see Figure 6 , Figure 7 , Figure 8 and Figure 9 The above figures schematically depict a backlight device according to a second preferred embodiment of the present invention. Figure 6 This is a top view schematic diagram of the backlight device according to a second preferred embodiment of the present invention; Figure 7 for Figure 6 A cross-sectional view of the backlight device along line BB; Figure 8A top view of the backlight device of the second preferred embodiment of the present invention, showing an essential component—a long strip of flexible circuit board—in an unbent state. Figure 9 This is a top view of a necessary component of the backlight device according to a second preferred embodiment of the present invention—a long strip of flexible circuit board—in a bent state. (See attached image.) Figure 8 As shown, the essential components of the light-emitting device 3 in the second preferred embodiment of the present invention are a strip-shaped flexible circuit board 32, a plurality of first light-emitting elements 34, a plurality of second light-emitting elements 36, and a plurality of third light-emitting elements 38, and the strip-shaped flexible circuit board 32 is in an unbent state. Figure 9 As shown, the essential components of the light-emitting device 3 in the second preferred embodiment of the present invention are a strip-shaped flexible circuit board 32, a plurality of first light-emitting elements 34, a plurality of second light-emitting elements 36, and a plurality of third light-emitting elements 38, and the strip-shaped flexible circuit board 32 is in a bent state. The backlight device 3 according to the second preferred embodiment of the present invention is used for a backlight keyboard.

[0061] like Figure 6 and Figure 7 As shown, the backlight device 3 according to the second preferred embodiment of the present invention includes a light guide plate 30, a strip-shaped flexible circuit board 32, a plurality of first light-emitting elements 34, a plurality of second light-emitting elements 36, and a plurality of third light-emitting elements 38.

[0062] The light guide plate 30 defines a longitudinal direction L and a transverse direction T. The light guide plate 30 has a top surface 301, a back surface 302 opposite to the top surface 301, a first transverse side 303, a second transverse side 304 opposite to the first transverse side 303, a first longitudinal side 305, a second longitudinal side 306 opposite to the first longitudinal side 305, a plurality of first through holes 307, a plurality of second through holes 308, and a plurality of third through holes 309. The plurality of first through holes 307 are arranged from the first transverse side 303 along the longitudinal direction L and are close to the first longitudinal side 305. The plurality of second through holes 308 are arranged from the first transverse side 303 along the longitudinal direction L and are close to the second longitudinal side 306. The plurality of third through holes 309 are arranged along the transverse direction T and are located between the plurality of first through holes 307 and the plurality of second through holes 308, and are close to the second transverse side 304. Each first through hole 307 has its own first light-incident surface 3072. Multiple first through-holes 307 have multiple first light-incident surfaces 3072 that alternately face the second longitudinal side 306 and the first longitudinal side 305. Each second through-hole 308 has its own second light-incident surface 3082. The multiple second light-incident surfaces 3082 of the multiple second through-holes 308 alternately face the first longitudinal side 305 and the second longitudinal side 306. Each third through-hole 309 has its own third light-incident surface 3092. The multiple third light-incident surfaces 3092 of the multiple third through-holes 309 alternately face the first transverse side 303 and the second transverse side 304.

[0063] like Figure 8 and Figure 9 As shown, the elongated flexible circuit board 32 includes a first elongated portion 321, a first bent portion 322 connecting the first elongated portion 321, a second elongated portion 323 connecting the first bent portion 322, a second bent portion 324 connecting the second elongated portion 323, and a third elongated portion 325 connecting the second bent portion 324. The first elongated portion 321 has a first upper surface 3212 and a first lower surface 3214, and defines a first length direction S1. The second elongated portion 323 has a second upper surface 3232 and a second lower surface 3234, and defines a second length direction S2. The third elongated portion 325 has a third upper surface 3252 and a third lower surface 3254, and defines a third length direction S3.

[0064] Continue to refer to Figure 8 and Figure 9 Multiple first light-emitting elements 34 are electrically bonded to the first lower surface 3214 of the first elongated portion 321 and arranged along the first length direction S1. Each first light-emitting element 34 corresponds to a first through-hole 307, and the light-emitting direction of each first light-emitting element 34 is the same as the orientation of the first light-incident surface 3072 of its corresponding first through-hole 307. Multiple second light-emitting elements 36 are electrically bonded to the third lower surface 3254 of the third elongated portion 325 and arranged along the third length direction S3. Each second light-emitting element 36 corresponds to a second through-hole 308, and the light-emitting direction of each second light-emitting element 36 is the same as the orientation of the second light-incident surface 3082 of its corresponding third through-hole 308. Multiple third light-emitting elements 38 are electrically bonded to the second upper surface 3232 of the second elongated portion 323 and arranged along the second length direction S2. Each third light-emitting element 38 corresponds to a third through-hole 309, and the light-emitting direction of each third light-emitting element 38 is the same as the orientation of the second light-incident surface 3092 of its corresponding second through-hole 309. By using light-emitting elements with different orientations and through holes with different orientations on the light guide plate, the backlight device of the present invention emits light more uniformly.

[0065] The first bend 322 and the second bend 324 are bent so that the first lower surface 3214 of the first elongated portion 321, the third lower surface 3254 of the third elongated portion 325, and the second upper surface 3232 of the second elongated portion 323 are coplanar. Figure 9 As shown, a long, flexible circuit board 32 is placed on the back surface 302 of the light guide plate 30 with a first lower surface 3214, a second upper surface 3232, and a third lower surface 3254, such that each first light-emitting element 34 is placed in its corresponding first through-hole 307, each second light-emitting element 36 is placed in its corresponding second through-hole 308, and each third light-emitting element 38 is placed in its corresponding third through-hole 309, as shown. Figure 7 As shown. It should be noted that, Figure 9 The top view of the elongated flexible circuit board 32 shown presents a U-shape. If the elongated flexible circuit board 32 is directly cut into a U-shape, the manufacturing process consumes a lot of materials and has extremely high manufacturing costs. Clearly, the backlight device 3 according to the first preferred embodiment of the present invention, by bending the first bending portion 322 and the second bending portion 324 to form the elongated flexible circuit board 32 that presents a U-shape in top view, has lower manufacturing costs.

[0066] Each first light-emitting element 34 emits a first light beam that strikes the first light-incident surface 3072 of its corresponding first through-hole 307, and then enters the light guide plate 30. Each second light-emitting element 36 emits a second light beam that strikes the second light-incident surface 3082 of its corresponding second through-hole 308, and then enters the light guide plate 30. Each third light-emitting element 38 emits a third light beam that strikes the third light-incident surface 3092 of its corresponding third through-hole 309, and then enters the light guide plate 30. Thus, according to the second backlight device of the present invention, the U-shaped strip-shaped flexible circuit board formed by bending, combined with the through-holes on the light guide plate with different orientations of the light-incident surfaces, makes the backlight device emit light more uniformly and has advantages such as power saving and low cost.

[0067] In one specific embodiment, each of the first light-emitting element 34, each of the second light-emitting element 36, and each of the third light-emitting element 38 may be a light-emitting diode.

[0068] In one specific embodiment, similarly Figure 6As shown, the first light-incident surface 3072 of the first through hole 307 closest to the second lateral side 304 faces the first longitudinal side 305 and is adjacent to the second lateral side 304. The third light-incident surface 3092 of the third through hole 309 closest to the first longitudinal side 305 faces the second lateral side 304 and is adjacent to the first longitudinal side 305. The third light-incident surface 3092 of the third through hole 309 closest to the second longitudinal side 306 faces the second lateral side 304 and is adjacent to the second longitudinal side 306. The second light-incident surface of the second through hole 308 closest to the second lateral side 304 faces the second longitudinal side 306 and is adjacent to the second lateral side 304. That is, the first light-incident surface 3072 of the first through-hole 307 and the second light-incident surface 3082 of the second through-hole 308, which are closest to the second lateral side 304, are both inclined toward the second lateral side 304; the third light-incident surface 3092 of the third through-hole 309, which are closest to the first longitudinal side 305 and the second longitudinal side 306, are respectively inclined toward the first longitudinal side 305 and the second longitudinal side 306. This enhances the illumination brightness of the area where the second lateral side 304 intersects with the first longitudinal side 305 and the area closest to the second longitudinal side 306, avoiding the problem of low brightness in the area of ​​the light guide plate corresponding to the bend of the circuit board, and making the backlight device emit light more uniformly.

[0069] In one specific embodiment, similarly Figure 6 As shown, the first distance d1 between the plurality of first through holes 307 and the first longitudinal side 305 and the second distance d2 between the plurality of second through holes 308 and the second longitudinal side 306 are one-fifth to one-half of the lateral length X of the first transverse side 303.

[0070] In one specific embodiment, similarly Figure 6 As shown, the third distance d3 between the multiple third through holes 309 and the second transverse side 304 is one-fifth to one-half of the longitudinal length Y of the first longitudinal side 305.

[0071] For further information, please refer to the following: Figure 8 and Figure 9According to a second preferred embodiment of the present invention, the backlight device 3 further includes a connecting flexible circuit board 39. The connecting flexible circuit board 39 includes a third bent portion 391 and a fourth elongated portion 392. The third bent portion 391 is connected to the leading edge 3236 of the second elongated portion 323. The fourth elongated portion 392 is connected to the third bent portion 391. In practical applications, the third bent portion 391 is bent so that a portion of the fourth elongated portion 392 is in close contact with the second lower surface 3234 of the second elongated portion 323. It should be noted that the fourth elongated portion 392 of the backlight device 3 according to the second preferred embodiment of the present invention is also elongated, so that the connecting flexible circuit board 39 and the elongated flexible circuit board 32 are molded together, which can also achieve the purpose of low material consumption, thereby reducing the manufacturing cost of the connecting flexible circuit board 39 and the elongated flexible circuit board 32.

[0072] Please see Figure 10 , Figure 11 , Figure 12 and Figure 13 The above figures schematically depict a backlight device according to a third preferred embodiment of the present invention. Figure 10 This is a top view schematic diagram of the backlight device according to a third preferred embodiment of the present invention; Figure 11 for Figure 10 A cross-sectional view of the central backlight device along the CC line; Figure 12 A top view of the backlight device of the third preferred embodiment of the present invention, showing an essential component—a long strip of flexible circuit board—in an unbent state. Figure 13 This is a top view of a necessary component of the backlight device in the third preferred embodiment of the present invention—a long strip of flexible circuit board—in a bent state. (See attached image.) Figure 12 As shown in the top view schematically illustrates the essential elements of the light-emitting device 4 according to the third preferred embodiment of the present invention—a strip-shaped flexible circuit board 42 and a plurality of light-emitting elements 44, with the strip-shaped flexible circuit board 42 in an unbent state. Figure 12 As shown, the essential components of the light-emitting device 4 according to the third preferred embodiment of the present invention are a strip-shaped flexible circuit board 42 and a plurality of light-emitting elements 44, and the strip-shaped flexible circuit board 42 is in a bent state. The backlight device 4 according to the third preferred embodiment of the present invention is used for a backlight keyboard.

[0073] like Figure 10 and Figure 11 As shown, the backlight device 4 according to the third preferred embodiment of the present invention includes a light guide plate 40, a strip-shaped flexible circuit board 42, and a plurality of light-emitting elements 44.

[0074] The light guide plate 40 defines a longitudinal direction L and a transverse direction T. The light guide plate 40 has a top surface 401, a back surface 402 opposite to the top surface 401, a first transverse side 403, a second transverse side 404 opposite to the first transverse side 403, a first longitudinal side 405, a second longitudinal side 406 opposite to the first longitudinal side 405, and a plurality of through holes 407. The plurality of through holes 407 are arranged along the transverse direction T and are located between the first longitudinal side 405 and the second longitudinal side 406. Each through hole 407 has its own light-incident surface 4072. The plurality of light-incident surfaces 4072 of the plurality of through holes 407 alternately face the first transverse side 403 and the second transverse side 404.

[0075] like Figure 12 and Figure 13 As shown, the elongated flexible circuit board 42 has an upper surface 422 and a lower surface 424 (shown in...). Figure 11 In the case of a long strip of flexible circuit board 42, the upper surface 422 of the long strip of flexible circuit board 42 is electrically bonded to the upper surface 422 of the long strip of flexible circuit board 42, and arranged along the length direction S4. Each first light-emitting element 44 corresponds to a through hole 407, and the light-emitting direction of each first light-emitting element 44 is the same as the orientation of the light-incident surface 4072 of its corresponding through hole 407. The upper surface 422 of the long strip of flexible circuit board 42 is placed on the back surface 402 of the light guide plate 40, such that each light-emitting element 44 is placed in its corresponding through hole 407, as shown in the figure. Figure 11 As shown, each light-emitting element 44 emits light that is directed toward the light-incident surface 4072 of its corresponding through-hole 407, and then into the light guide plate 40. Thus, the third backlight device 4 according to the present invention emits light more uniformly and has advantages such as power saving and low cost.

[0076] In one specific embodiment, each light-emitting element 44 may be a light-emitting diode.

[0077] In one specific embodiment, the distance d4 between the plurality of through holes 407 and the second transverse side 404 is half the longitudinal length Y of the first longitudinal side 405.

[0078] For further information, please continue to refer to [the relevant resources / references]. Figure 12 and Figure 13According to a third preferred embodiment of the present invention, the backlight device 4 further includes a connecting flexible circuit board 46. The connecting flexible circuit board 46 includes a bent portion 461 and an elongated portion 462. The bent portion 461 is connected to the leading edge 426 of the elongated flexible circuit board 42. The elongated portion 462 is connected to the bent portion 461. The bent portion 461 is bent so that a portion of the elongated portion 462 is in close contact with the lower surface 424 of the elongated flexible circuit board 42. It should be noted that the elongated portion 462 of the backlight device 4 according to the third preferred embodiment of the present invention is also elongated. Molding the connecting flexible circuit board 46 and the elongated flexible circuit board 42 together can also achieve the purpose of low material consumption, thereby reducing the manufacturing cost of the connecting flexible circuit board 46 and the elongated flexible circuit board 42.

[0079] Based on the backlit keyboard of a notebook computer, one example of the present invention uses a backlight device 2 according to a first preferred embodiment of the present invention as its architecture, employing a light guide plate with a thickness of 0.25 mm and 29 LEDs with a thickness of 0.4 mm. The voltage and current of the example of the present invention are listed in Table 1. For comparison, Comparative Example 1 uses... Figure 1 The backlight device 1 shown is an example of a backlight device that uses a 0.25mm thick light guide plate and 15 0.4mm thick LEDs. Its voltage and current are listed in Table 1. Similarly, for comparison, Comparative Example 2 uses a backlight device that employs sub-millimeter light-emitting diodes. It also uses a 0.25mm thick light guide plate and 95 mini-LEDs. Its power consumption is also listed in Table 1.

[0080] Table 1

[0081]

[0082] Based on Table 1, the power consumption of the examples, comparative example 1, and comparative example 2 of the present invention can be clearly calculated. Compared to the power consumption of comparative example 1, comparative example 2 saves 28%–40% of power, while the examples of the present invention save 21%–30%. Although comparative example 2 is more power-efficient, its architecture has a higher manufacturing cost. The examples of the present invention also have considerably lower power consumption, and their architecture has a lower manufacturing cost.

[0083] From the above detailed description of the present invention, it can be clearly understood that the backlight device according to the present invention not only emits light more uniformly, but also has the advantages of saving power and low cost, especially the low manufacturing cost of the flexible circuit board used.

[0084] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A backlight device for an illuminated keyboard, characterized in that, The backlight device includes: A light guide plate defines a longitudinal direction and a transverse direction, and has a top surface, a back surface opposite to the top surface, a first transverse side, a second transverse side opposite to the first transverse side, a first longitudinal side, a second longitudinal side opposite to the first longitudinal side, a plurality of first through holes, a plurality of second through holes, and a plurality of third through holes. The plurality of first through holes are arranged from the first transverse side along the longitudinal direction and are close to the first longitudinal side. The plurality of second through holes are arranged from the first transverse side along the longitudinal direction and are close to the second longitudinal side. The plurality of third through holes are adjacent to the first transverse side. The second transverse side is arranged along the transverse direction and located between the plurality of first through holes and the plurality of second through holes. Each first through hole has its own first light-incident surface. The plurality of first light-incident surfaces corresponding to the plurality of first through holes alternately face the second longitudinal side and the first longitudinal side. Each second through hole has its own second light-incident surface. The plurality of second light-incident surfaces corresponding to the plurality of second through holes alternately face the first longitudinal side and the second longitudinal side. Each third through hole has its own third light-incident surface. The plurality of third light-incident surfaces corresponding to the plurality of third through holes face the first transverse side. A long strip-shaped flexible circuit board includes a first long strip portion, a first bent portion connecting the first long strip portion, a second long strip portion connecting the first bent portion, a second bent portion connecting the second long strip portion, and a third long strip portion connecting the second bent portion. The first long strip portion has a first upper surface and a first lower surface and defines a first length direction. The second long strip portion has a second upper surface and a second lower surface and defines a second length direction. The third long strip portion has a third upper surface and a third lower surface and defines a third length direction. A plurality of first light-emitting elements are electrically bonded to the first lower surface of the first elongated portion and arranged along the first length direction, and each first light-emitting element corresponds to a first through hole; A plurality of second light-emitting elements are electrically bonded to the third lower surface of the third elongated portion and arranged along the third length direction, each second light-emitting element corresponding to a second through hole; as well as Multiple third light-emitting elements are electrically bonded to the second upper surface of the second elongated portion and arranged along the second length direction, with each third light-emitting element corresponding to a third through hole; The first and second bending portions are bent such that the first lower surface of the first elongated portion, the third lower surface of the third elongated portion, and the second upper surface of the second elongated portion are on the same plane. The elongated flexible circuit board is placed on the back side of the light guide plate with the first lower surface, the second upper surface, and the third lower surface, so that each first light-emitting element is placed in its corresponding first through hole, each second light-emitting element is placed in its corresponding second through hole, and each third light-emitting element is placed in its corresponding third through hole. Each first light-emitting element emits a first light beam that strikes the first light-incident surface of its corresponding first through hole and then enters the light guide plate. Each second light-emitting element emits a second light beam that strikes the second light-incident surface of its corresponding second through hole and then enters the light guide plate. Each third light-emitting element emits a third light beam that strikes the third light-incident surface of its corresponding third through hole and then enters the light guide plate.

2. The backlight device as claimed in claim 1, characterized in that, The first distance between the plurality of first through holes and the first longitudinal side and the second distance between the plurality of second through holes and the second longitudinal side are one-fifth to one-half of the lateral length of the first transverse side.

3. The backlight device as described in claim 1, characterized in that, The backlight device further includes a connecting flexible circuit board, which includes a third bend and a fourth elongated portion. The third bend is connected to the leading edge of the second elongated portion, and the fourth elongated portion is connected to the third bend. The third bend is bent so that a portion of the fourth elongated portion is in close contact with the second lower surface of the second elongated portion.

4. A backlight device for an illuminated keyboard, characterized in that, The backlight device includes: A light guide plate defines a longitudinal direction and a transverse direction, and the light guide plate has a top surface, a back surface opposite to the top surface, a first transverse side, a second transverse side opposite to the first transverse side, a first longitudinal side, a second longitudinal side opposite to the first longitudinal side, a plurality of first through holes, a plurality of second through holes, and a plurality of third through holes. The plurality of first through holes are arranged from the first transverse side along the longitudinal direction and close to the first longitudinal side. The plurality of second through holes are arranged from the first transverse side along the longitudinal direction and close to the second longitudinal side. The plurality of third through holes are arranged along the transverse direction and positioned... Between the plurality of first through holes and the plurality of second through holes and near the second lateral side, each first through hole has its own first light-incident surface, and the plurality of first light-incident surfaces corresponding to the plurality of first through holes alternately face the second longitudinal side and the first longitudinal side. Each second through hole has its own second light-incident surface, and the plurality of second light-incident surfaces corresponding to the plurality of second through holes alternately face the first longitudinal side and the second longitudinal side. Each third through hole has its own third light-incident surface, and the plurality of third light-incident surfaces corresponding to the plurality of third through holes alternately face the first lateral side and the second lateral side. A long strip-shaped flexible circuit board includes a first long strip portion, a first bent portion connecting the first long strip portion, a second long strip portion connecting the first bent portion, a second bent portion connecting the second long strip portion, and a third long strip portion connecting the second bent portion. The first long strip portion has a first upper surface and a first lower surface and defines a first length direction. The second long strip portion has a second upper surface and a second lower surface and defines a second length direction. The third long strip portion has a third upper surface and a third lower surface and defines a third length direction. A plurality of first light-emitting elements are electrically bonded to the first lower surface of the first elongated portion and arranged along the first length direction, and each first light-emitting element corresponds to a first through hole; A plurality of second light-emitting elements are electrically bonded to the third lower surface of the third elongated portion and arranged along the third length direction, each second light-emitting element corresponding to a second through hole; as well as Multiple third light-emitting elements are electrically bonded to the second upper surface of the second elongated portion and arranged along the second length direction, with each third light-emitting element corresponding to a third through hole; The first and second bending portions are bent such that the first lower surface of the first elongated portion, the third lower surface of the third elongated portion, and the second upper surface of the second elongated portion are on the same plane. The elongated flexible circuit board is placed on the back side of the light guide plate with the first lower surface, the second upper surface, and the third lower surface, so that each first light-emitting element is placed in its corresponding first through hole, each second light-emitting element is placed in its corresponding second through hole, and each third light-emitting element is placed in its corresponding third through hole. Each first light-emitting element emits a first light beam that strikes the first light-incident surface of its corresponding first through hole and then enters the light guide plate. Each second light-emitting element emits a second light beam that strikes the second light-incident surface of its corresponding second through hole and then enters the light guide plate. Each third light-emitting element emits a third light beam that strikes the third light-incident surface of its corresponding third through hole and then enters the light guide plate.

5. The backlight device as described in claim 4, characterized in that, The first light-incident surface of the first through-hole closest to the second lateral side faces the first longitudinal side and is adjacent to the second lateral side. The third light-incident surface of the third through-hole closest to the first longitudinal side faces the second lateral side and is adjacent to the first longitudinal side. The third light-incident surface of the third through-hole closest to the second longitudinal side faces the second lateral side and is adjacent to the second longitudinal side. The second light-incident surface of the second through-hole closest to the second lateral side faces the second longitudinal side and is adjacent to the second lateral side.

6. The backlight device as claimed in claim 4, characterized in that, The first distance between the plurality of first through holes and the first longitudinal side and the second distance between the plurality of second through holes and the second longitudinal side are one-fifth to one-half of the lateral length of the first transverse side.

7. The backlight device as claimed in claim 4, characterized in that, The third distance between the plurality of third through holes and the second transverse side is one-fifth to one-half of the longitudinal length of the first longitudinal side.

8. The backlight device as claimed in claim 4, characterized in that, The backlight device further includes a connecting flexible circuit board, which includes a third bend and a fourth elongated portion. The third bend is connected to the leading edge of the second elongated portion, and the fourth elongated portion is connected to the third bend. The third bend is bent so that a portion of the fourth elongated portion is in close contact with the second lower surface of the second elongated portion.

9. A backlight device for a backlight keyboard, characterized in that, The backlight device includes: A light guide plate defines a longitudinal direction and a transverse direction, and the light guide plate has a top surface, a back surface opposite to the top surface, a first transverse side, a second transverse side opposite to the first transverse side, a first longitudinal side, a second longitudinal side opposite to the first longitudinal side, and a plurality of through holes. The plurality of through holes are arranged along the transverse direction and located between the first longitudinal side and the second longitudinal side. Each through hole has its own light-incident surface, and the plurality of light-incident surfaces corresponding to the plurality of through holes alternately face the first transverse side and the second transverse side. A long, flexible circuit board having an upper surface and a lower surface and defining a length direction; and Multiple light-emitting elements are electrically bonded to the upper surface of the long strip-shaped flexible circuit board and arranged along the length direction, with each first light-emitting element corresponding to a through hole; The long strip of flexible circuit board is placed on the back of the light guide plate with its upper surface, so that each light-emitting element is placed in its corresponding through hole, and each light-emitting element emits light towards the light-incident surface of its corresponding through hole and then into the light guide plate.

10. The backlight device as claimed in claim 9, characterized in that, The distance between the plurality of through holes and the second transverse side is half the longitudinal length of the first longitudinal side; or, the backlight device further includes a connecting flexible circuit board, the connecting flexible circuit board including a bent portion and an elongated portion, the bent portion being connected to the leading edge of the elongated flexible circuit board, the elongated portion being connected to the bent portion, wherein the bent portion is bent so that a portion of the elongated portion is in close contact with the lower surface of the elongated flexible circuit board.

Images