CN114256018A

CN114256018A - Backlight module

Info

Publication number: CN114256018A
Application number: CN202011025306.4A
Authority: CN
Inventors: 古佑铨
Original assignee: Chongqing Dafang Electronics Co ltd; Darfon Electronics Corp
Current assignee: Chongqing Dafang Electronics Co ltd; Darfon Electronics Corp
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2022-03-29

Abstract

The invention discloses a backlight module which emits light in a first direction and a second direction which are opposite. The backlight module comprises a light guide plate, a covering sheet, a substrate sheet and a light emitting piece. The cover sheet is disposed on the top side of the light guide sheet along the first direction. The cover sheet defines a plurality of first light-transmitting regions. The first light-transmitting areas correspond to the keys respectively. The substrate sheet is arranged on the bottom side of the light guide sheet along the second direction. The substrate sheet defines at least one second light-transmitting region. The light emitting part outputs incident light to enter the light guide sheet, after entering the light guide sheet, a first part of the incident light is transmitted from the plurality of first light transmission areas to the first direction through the light guide sheet, and a second part of the incident light is transmitted from the second light transmission areas to the second direction through the light guide sheet. The invention can lead the light of the backlight module to irradiate different directions, and achieves the decoration or indication function of double-sided backlight on the premise of not greatly increasing the whole thickness of the device.

Description

Backlight module

Technical Field

The present invention relates to a backlight module, and more particularly, to a backlight module capable of emitting light in multiple directions.

Background

The light emitting keyboard is characterized in that a backlight module is arranged below a keyboard module, and a light emitting element of the backlight module guides light rays to each key of the keyboard by utilizing the design of a light guide plate to irradiate the peripheries of the keys or keycaps of the keys so as to have decoration and indication effects.

Generally speaking, the keyboard module has a plurality of keys disposed on a bottom plate, and a keyboard circuit board for triggering signals when the keys are pressed is also disposed under the plurality of keys and opposite to the bottom plate. Each key can at least comprise a keycap, a bracket connecting the keycap and the bottom plate and an elastic piece providing restoring force for the keycap. Generally, the backlight module is disposed below the key to provide a light source and a light guide structure for illuminating the key cap. The backlight module can be arranged below the bottom plate, and the bottom plate is provided with a light-transmitting hole for light to pass through; however, the backlight module may be disposed between the base plate and the keycap, if desired.

Regardless of the relative position between the backlight module and the bottom plate, the backlight module must guide the light to the corresponding region of each key and irradiate each key cap upward.

Disclosure of Invention

In view of the problems in the prior art, the present invention provides a backlight module to solve the above problems.

Therefore, the technical problem to be solved by the present invention is to provide a backlight module, the backlight module emits light in a first direction and a second direction opposite to each other, the backlight module is adjacent to a plurality of keys along the first direction, the backlight module comprises:

a light guide sheet;

the cover sheet is arranged on the top side of the light guide sheet along the first direction, and defines a plurality of first light transmission areas which respectively correspond to the plurality of keys;

the substrate sheet is arranged on the bottom side of the light guide sheet along the second direction and defines at least one second light-transmitting area; and

and the light emitting piece outputs incident light to enter the light guide sheet, after the incident light enters the light guide sheet, a first part of light of the incident light is transmitted to the first direction from the plurality of first light transmission areas of the covering sheet through the light guide sheet, and a second part of light of the incident light is transmitted to the second direction from the at least one second light transmission area of the base material sheet through the light guide sheet.

As an optional technical solution, the cover sheet has at least one first cover layer defining the first transparent region, the at least one first cover layer includes an opaque ink layer and/or a reflective ink layer, and the at least one first cover layer does not include the opaque ink layer or the reflective ink layer in the first transparent region.

As an optional technical solution, the substrate sheet has at least one second cover layer defining the at least one second light-transmitting area, the at least one second cover layer includes a light-shielding ink layer and/or a light-reflecting ink layer, and the at least one second cover layer does not include the light-shielding ink layer or the light-reflecting ink layer in the at least one second light-transmitting area.

As an optional technical scheme, the light guide plate is provided with a plurality of groups of light reflecting structures;

the multiple groups of light reflecting structures are arranged on the top surface of the light guide sheet to reflect the first part of light to irradiate towards the first direction; alternatively, the first and second electrodes may be,

the multiple groups of light reflecting structures are arranged on the bottom surface of the light guide sheet to reflect the second part of light to irradiate towards the second direction.

As an optional technical solution, the light guide plate has a hole, the cover sheet has a plurality of protrusions, and the plurality of protrusions have bent sections inserted into the hole, so that the inner surfaces of the plurality of protrusions reflect the second portion of light to the at least one second light-transmitting region.

As an optional technical solution, the cover sheet has at least one first cover layer, and the at least one first cover layer includes a reflective ink layer, and the reflective ink layer is coated on the plurality of protruding portions respectively.

As an optional technical solution, the backlight module is adjacent to the protective cover along the second direction, and the protective cover has at least one light penetration portion corresponding to the at least one second light-transmitting region of the substrate sheet.

As an optional technical solution, the backlight module is adjacent to the fan unit along the second direction, and the at least one second light-transmitting area corresponds to the fan unit.

As an optional technical solution, the light guide sheet includes a U-shaped slot to define a light guide fin, and at least a portion of a light exit section of the light guide fin is exposed to a bottom side of the light guide sheet, so that the second portion of light is locally irradiated toward the second direction.

As an optional technical solution, the backlight module further includes a supporting member, and the supporting member supports the light guiding fin to incline to the second direction by an included angle, so that at least a part of the light emitting section of the light guiding fin is exposed to the bottom side of the light guiding fin.

As an optional technical solution, the cover sheet has a cover flap, the cover flap covers the light guide flap of the light guide sheet, and the abutting member abuts against the cover flap and also abuts against the light guide flap to incline toward the second direction.

The invention also provides a backlight module, which comprises:

the light guide plate is provided with at least one first through hole;

the substrate sheet is arranged on one side of the light guide sheet and provided with at least one second through hole, and the at least one second through hole corresponds to the at least one first through hole;

a cover sheet disposed on the other side of the light guide sheet relative to the substrate sheet, the cover sheet having at least one third perforation corresponding to the at least one first perforation;

the light-emitting piece corresponds to the at least one first through hole, the at least one second through hole and the at least one third through hole; and

the light guide pipe is adjacent to the luminous piece along a second direction and is provided with a first end and a second end which are opposite, the first end points to the luminous piece, and the second end extends out of the substrate sheet.

As an optional technical solution, the backlight module is adjacent to the plurality of keys along the first direction, the light emitting member includes a first light source and a second light source, the first light source illuminates the plurality of keys through the light guide sheet towards the first direction, and the second light source penetrates through the at least one first through hole of the light guide sheet along the second direction.

As an optional technical solution, the backlight module is adjacently disposed in the fan unit along the second direction, and the second end of the light pipe is located in the fan unit.

The present invention also provides a backlight module, the backlight module is adjacent to the fan unit along the second direction, the backlight module and the fan unit are respectively arranged at opposite sides of a partition, the partition has at least one first light-transmitting region, the backlight module comprises:

a light source circuit board disposed at the other side of the partition with respect to the fan unit;

a buffer sheet disposed between the spacer and the light source circuit board; and

the light emitting piece is arranged on the light source circuit board, corresponds to the at least one first light transmitting area of the separating piece, and emits incident light output by the light emitting piece to the fan unit towards the second direction through the at least one first light transmitting area.

As an optional technical solution, the backlight module further includes a light pipe, the light pipe has a first end and a second end opposite to each other, the first end is directed to the light emitting element, and the second end extends into the fan unit.

As an alternative solution, the buffer sheet has at least one raised structure to cover the luminous member.

As an optional technical solution, the backlight module further includes a top-abutting member and a light guide fin on the buffer sheet, wherein one end of the light guide fin points to the light emitting member, and the top-abutting member abuts and bends an open end of the light guide fin to point to the second direction.

Compared with the prior art, the backlight module emits light in the first direction and the second direction which are opposite. The backlight module comprises a light guide plate, a covering sheet, a substrate sheet and a light emitting piece. The cover sheet is disposed on the top side of the light guide sheet along the first direction. The cover sheet defines a plurality of first light-transmitting regions. The first light-transmitting areas correspond to the keys respectively. The substrate sheet is arranged on the bottom side of the light guide sheet along the second direction. The substrate sheet defines at least one second light-transmitting region. The light emitting part outputs incident light to enter the light guide sheet, after entering the light guide sheet, a first part of the incident light is transmitted from the plurality of first light transmission areas to the first direction through the light guide sheet, and a second part of the incident light is transmitted from the second light transmission areas to the second direction through the light guide sheet. The invention can guide the illumination light of the backlight module in the keyboard to irradiate different directions to be used for illuminating adjacent parts at different positions, and achieves the decoration or indication function of double-sided backlight on the premise of not greatly increasing the integral thickness of the device.

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Drawings

Fig. 1A is an external view of a computing device and a keyboard according to a first embodiment of the invention.

Fig. 1B is a schematic top view of a keyboard according to a first embodiment of the present invention.

Fig. 2 is a partial structural sectional view of the keypad of fig. 1A.

Fig. 3 is a schematic view of a backlight module according to a first embodiment of the invention.

Fig. 4 is a schematic view of a backlight module according to a second embodiment of the invention.

Fig. 5 is a schematic view of a backlight module according to a third embodiment of the invention.

Fig. 6 is a schematic view of a backlight module according to a fourth embodiment of the invention.

Fig. 7 is a schematic view of a backlight module according to a fifth embodiment of the invention.

Fig. 8 and 9 are schematic views of a backlight module according to a sixth embodiment of the invention at different viewing angles.

Fig. 10 is a schematic view of a backlight module according to a seventh embodiment of the invention.

Fig. 11 is a schematic view of a backlight module according to an eighth embodiment of the invention.

Fig. 12 is a schematic view of a backlight module according to a ninth embodiment of the invention.

Fig. 13 is a schematic view of a backlight module according to a tenth embodiment of the invention.

Fig. 14 is a schematic external view of a substrate sheet according to the first embodiment of the present invention.

Fig. 15 is a schematic bottom-side view of a computing device and a protective cover according to an eleventh embodiment of the invention.

Fig. 16 is a partial structural sectional view of the keypad of fig. 15.

Detailed Description

In order to further understand the objects, structures, features and functions of the present invention, the following embodiments are described in detail.

Referring to fig. 1A, fig. 1B and fig. 2, fig. 1A is an external view of a computing device 1 and a keyboard 10 according to a first embodiment of the invention, fig. 1B is a top view of the keyboard 10 according to the first embodiment of the invention, and fig. 2 is a schematic view of the keyboard 10 of fig. 1A along a section line a-a'. The computing device 1 is, for example, a notebook computer, the keyboard 10 is embedded in the casing 100 of the computing device 1, the casing 100 has an upper casing 100A and a lower casing 100B which are vertically aligned, the keyboard 10 has a plurality of keys 12, the keys 12 are arranged in a rectangular array, each key 12 is partially exposed out of the upper casing 100A of the computing device 1, and the bottom side of the keyboard 10 corresponds to the lower casing 100B. A backlight module 16 is disposed between the lower side of the keypad 10 and the lower case 100B. The computing device 1 may have the fan unit 14 disposed in the casing 100, for example, between the bottom side of the keyboard 10 and the lower casing 100B. In various embodiments of the present invention, the backlight module 16 shared in the keyboard 10 is utilized to illuminate the components (such as the keys 12 and the fan unit 14) located at different directions around the backlight module 16. The key 12 may be composed of a key cap 18, a restoring member 20, a supporting member 22, a thin film circuit board 24, and a base plate 25. In various embodiments, the thin film circuit board 24 and the backplane 25 may be interchanged in the stacking order.

Referring to fig. 1A, fig. 1B and fig. 2 to fig. 3, fig. 3 is a schematic view of a backlight module 16A (16) according to a first embodiment of the present invention. The backlight module 16A may emit light toward the first direction D1 and the opposite second direction D2. The backlight module 16A may be adjacent to the key 12 along the first direction D1. Backlight module 16A may include light guide 26, cover sheet 28, substrate sheet 30, and one or more light emitters 32. Cover sheet 28 may be disposed on the top side of light guide sheet 26 along first direction D1 and substrate sheet 30 may be disposed on the bottom side of light guide sheet 26 along second direction D2. The light-emitting member 32 may be disposed beside the light guide plate 26 or penetrate into a hole (e.g., the opening 262 in fig. 2) of the light guide plate 26; the light-emitting element 32 is usually disposed on a light source circuit board (not shown) attached to the lower surface of the substrate sheet 30 or the upper surface of the cover sheet 28, such that the light-emitting element 32 extends into the hole or side of the light guide sheet 26 from the upper or lower side of the light guide sheet 26. The light emitting member 32 may be disposed on one side of the integrated keyboard 10, for example, in fig. 1B, a plurality of light emitting members 32 are arranged along the extending direction of the long side of the keyboard 10 and are close to a plurality of keys 12 on the outermost row of long sides; in various embodiments, the plurality of light emitters 32 may also be arranged along a direction approximately parallel to the extension of the short sides of the keyboard 10 and in a central section of the keyboard 10. Each of the light emitting members 32 is disposed on one side of the light guide 26 or disposed in the opening 262 of the light guide 26, so that the incident light B output from the light emitting member 32 enters the light guide 26.

The cover sheet 28 defines one or more first light transmitting regions 282. The cover sheet 28 of the present invention can be coated on the upper surface and/or the lower surface of the transparent substrate to define a first light-transmitting region 282; or cover sheet 28 may be an opaque substrate with holes cut to define first light-transmitting zone 282. In this embodiment, the first cover layer 281 can be used to define a plurality of first light-transmitting regions 282 on the inner surface or the outer surface of the transparent substrate. For example, the first cover layer 281 can include an opaque ink layer (e.g., black ink) and/or a reflective ink layer (e.g., white ink) disposed outside the first transparent region 282 of the cover sheet 28 for reflecting the incident light B; in other words, the first cover layer 281 does not dispose the opaque ink layer or the reflective ink layer on the first transparent area 282, and the incident light B can illuminate the key 12 through the first transparent area 282.

The substrate sheet 30 defines one or more second light-transmitting regions 302. The substrate sheet 30 of the present invention can be coated on the upper surface and/or the lower surface of the transparent substrate to define the second light-transmitting region 302; or substrate sheet 30 may be an opaque substrate with holes cut to define second light-transmitting region 302. In this embodiment, the second cover layer 301 can be used to define a plurality of second light-transmitting regions 302 on the inner surface or the outer surface of the transparent substrate. For example, the second cover layer 301 may include a light-shielding ink layer (e.g., black ink) and/or a light-reflecting ink layer (e.g., white ink) disposed outside the second transparent region 302 of the substrate sheet 30, i.e., the second cover layer 301 does not dispose the light-shielding ink layer or the light-reflecting ink layer on the second transparent region 302; and the position of the second light-transmitting area 302 may correspond to the fan unit 14.

Light is transmitted within the light guide 26 along the plane of the light guide 26, mostly by total reflection, at the light guide 26, so that light can be transmitted to the keys 12 at each corner of the keyboard 10 away from the light emitter 32 in fig. 1B. In order to allow enough light to pass through the first transparent area 282, the light guide plate 26 may have a plurality of sets of reflective structures 261 for total reflection, the reflective structures 261 are disposed on the bottom surface (the opposite side of the light exit side) of the light guide plate 26, and the reflective structures 261 may be reflective ink microdot clusters, micro-concave patterns or micro-protruding structures disposed on the surface of the light guide plate 26. After the incident light B of the light emitting element 32 enters the light guiding sheet 26, a first portion of the light B1 of the incident light B can be transmitted to the first direction D1 through the light reflecting structure 261 of the light guiding sheet 26, and pass through the first light-transmitting region 282 of the cover sheet 28 to illuminate the key 12; the second portion of the incident light B, i.e., the light B2, is transmitted through the light reflecting structure 261 of the light guiding sheet 26 toward the second direction D2, and passes out of the second light-transmitting region 302 of the substrate sheet 30 to illuminate the fan unit 14.

As shown in fig. 2 and 3, the backlight module 16A may be adjacent to the fan unit 14 along the second direction D2, so the position of the second light-transmitting area 302 may correspond to the fan unit 14 to form a decorative pattern. Referring to fig. 3 and 14, fig. 14 is an external view of a substrate sheet 30 according to a first embodiment of the invention. The first embodiment illustrates that the substrate sheet 30 may be provided with a second light-transmitting area 302, so that a second portion of the light rays B2 of the incident light B of the luminescent member 32 passes out of the substrate sheet 30 through the second light-transmitting area 302 to illuminate the fan unit 14. The shape and size of the second transparent area 302 may correspond to the shape and size of the fan unit 14, and the light guiding plate 26 is also provided with the light reflecting structure 261 according to the shape and size distribution of the second transparent area 302. Meanwhile, the lower housing 100B may also be provided with a light hole 101 for allowing light passing through the fan unit 14 to pass out. In other words, the shape and size layout of one or both (or at least one of both) of the second light-transmitting region 302 of the substrate sheet 30 and the light-transmitting holes 101 of the lower housing 100B can define the illumination and decoration effects of the backlight module 16/16a in the second direction D2 (i.e., the side closer to the fan unit 14). Of course, in some embodiments, the light reflecting structure 261 may also be directly disposed on the top side of the light guiding plate 26 to directly guide the second portion of the light ray B2 to the second direction D2.

As mentioned above, in the first embodiment, the cover sheet 28 and/or the first light-transmitting region 282 thereof can be made of a solid transparent material, and the substrate sheet 30 and/or the second light-transmitting region 302 thereof can also be made of a solid transparent material, but the practical application is not limited thereto.

Referring to fig. 4, fig. 4 is a schematic view of a backlight module 16B (16) according to a second embodiment of the invention. In the second embodiment, the components having the same component names or component numbers as those in the first embodiment have the same structures and functions, and description thereof will not be repeated. The cover sheet 28 of the backlight module 16B may form one or more first through holes as the first light-transmitting regions 282. In addition, one or more second through holes may be formed in the substrate sheet 30 as the second light-transmitting regions 302.

Referring to fig. 3 to 5, fig. 5 is a schematic view of a backlight module 16C (16) according to a third embodiment of the present invention. In the third embodiment, the components having the same component names or component numbers as those in the other embodiments of the present invention have the same structures and functions, and are not described again. The second cover layer 301 (i.e. the light-shielding ink layer and/or the reflective ink layer) of the first and second embodiments is disposed on the bottom side of the substrate sheet 30 away from the light guide sheet 26. The second cover layer 301 of the third embodiment can then be disposed on the top side of the substrate sheet 30 adjacent the light guide sheet 26, e.g., between the light guide sheet 26 and the substrate sheet 30.

In the first to third embodiments, i.e. the light emitting element 32 in fig. 1A to 5, besides providing the transmission of the first part of the incident light in the first direction D1 (for illuminating the keys 12), the transmission of the second part of the incident light in the second direction D2 (for illuminating the fan unit 14) is also provided. However, in consideration of the sufficient or insufficient amount of light and the specific optical effect, the light-emitting member according to the embodiment of the present invention may also provide a second portion of light to be irradiated in the second direction D2 by using an additional second light source (for example, the light-emitting member 40/48/58/68 described below) as needed in addition to the light-emitting member 32 (serving as the first light source). The light emitting member 32 as the first light source and the light emitting member 40/48/58/68 as the second light source may be implemented by a plurality of different light emitting diodes on the same light source circuit board or on different light source circuit boards. In the following embodiments, the light emitting element includes a first light source and a second light source, wherein the light emitting element 32 as the first light source is omitted for brevity, and only the light emitting element 40/48/58/68 as the second light source is described.

Referring to fig. 1A, fig. 2 and fig. 6, fig. 6 is a schematic view of a backlight module 16D (16) according to a fourth embodiment of the present invention. In the fourth embodiment, the components having the same component names or component numbers as those in the other embodiments of the present invention have the same structures and functions, and are not described again. The light guide 34 of backlight module 16D is disposed between cover sheet 36 and substrate sheet 38. Cover sheet 36 may have a plurality of first light-transmitting regions 361 and substrate sheet 38 may have second light-transmitting regions 381. In this embodiment, the light emitting member 32 as the first light source for providing the first portion of light to transmit/irradiate the key 12 along the first direction D1 is omitted from illustration, and the light emitting member 40 as the second light source may be disposed in the mounting hole 341 of the light guiding sheet 34 and the mounting hole 382 of the base material sheet 38. In the fourth embodiment, the covering sheet 36 may have a plurality of protrusions 362, each protrusion 362 protrudes in an arch shape toward the first direction D1 and is recessed toward the second direction D2, and covers the corresponding light-emitting element 40. The light guide plate 34 may have a plurality of holes 342, and one or more bent segments 362a bent downward are disposed around each protrusion 362 to be inserted into the corresponding hole 342, so as to reflect the second portion of light B2 to the second light-transmitting region 381.

The first cover layer of cover sheet 36 may include a reflective ink layer coated on the lower surface and/or the upper surface of the plurality of protrusions 362. The light emitting element 40 can output the incident light B along the first direction D1, and the incident light B can be projected onto the cover sheet 36 through the light guide sheet 34, and then transmitted to the second direction D2 through the second light transmission region 381 by the reflection of the light reflecting ink layer. The inner surface of the protrusion 362 may reflect the incident light B projected toward both left and right sides of the light emitting member 40 toward the second direction D2 to increase the light intensity passing through the second light transmission region 381 along the second direction D2. The second light-transmitting region 381 of the fourth embodiment is made of a transparent material, but the practical application is not limited thereto.

Referring to fig. 7, fig. 7 is a schematic view of a backlight module 16E (16) according to a fifth embodiment of the invention. In the fifth embodiment, the components having the same component names or component numbers as those in the other embodiments of the present invention have the same structures and functions, and are not described again. The backlight module 16E is provided with a through hole on the substrate sheet 38 as a second light-transmitting region 381.

In addition, the fourth and fifth embodiments can further dispose a light-shielding ink layer and/or a reflective ink layer on the substrate sheet 38. The light-shielding ink layer can be used to prevent the incident light B from penetrating from the area outside the second transparent region 381 of the substrate 38. The reflective ink layer can be used to reflect incident light B projected beyond the second light transmitting area 381 of the substrate sheet 38 back to the cover sheet 36, and then reflect through the second light transmitting area 381 via the reflective ink layer of the cover sheet 36, thereby increasing the light intensity passing through the second light transmitting area 381 along the second direction D2.

Referring to fig. 8 and 9, fig. 8 and 9 are schematic views of a backlight module 16F (16) according to a sixth embodiment of the present invention at different viewing angles. In the sixth embodiment, the components having the same component names or component numbers as those in the other embodiments of the present invention have the same structures and functions, and are not described again. The light guide 42 of backlight module 16F may be disposed between cover sheet 44 and substrate sheet 46. The light guide 42 may have U-shaped cut 421 to define a light guide flap 422. The light-in section 422a of the light guide plate 422 can be aligned with the light-emitting member 48, and the light-out section 422b of the light guide plate 422 can be partially exposed to the bottom side 423 of the light guide plate 42. The second portion of the light B2 of the incident light B output by the light emitting element 48 (the first light source) is irradiated in the second direction D2 through the light guiding wing 422, and the first light source for irradiating the key 12 in the first direction D1 is omitted.

The backlight module 16F optionally includes a supporting member 50 for supporting the light guiding fins 422 to tilt at a specific angle along the second direction D2, i.e. bending the light guiding fins 422 of the light guiding sheet 42 to make the light section 422b partially exposed to the bottom side 423 of the light guiding sheet 42. Furthermore, the covering sheet 44 may be selectively cut to form the covering tabs 441, and the forming positions of the covering tabs 441 may correspond to the positions of the light guide tabs 422. The cover flap 441 can cover the light guide flap 422 of the light guide 42, and the top supporting member 50 is against the upper surface of the cover flap 441, and the top supporting member 50 is inclined toward the second direction D2 along with the top supporting light guide flap 422, and is located between the bottom side of the key 12 (the bottom plate 25) and the cover flap 441.

Referring to fig. 10, fig. 10 is a schematic view of a backlight module 16G (16) according to a seventh embodiment of the invention. In the seventh embodiment, the elements having the same element names or element numbers as those in the other embodiments of the present invention have the same structures and functions, and description thereof is not repeated. Backlight module 16G may include a light guide 52, a substrate 54, a cover 56, a first light source (not shown), one or more light emitting elements 58 (second light sources), and one or more light pipes 60. Substrate sheet 54 and cover sheet 56 may be disposed on opposite sides of light guiding sheet 52, respectively. Light guide 52 may have first through-holes 521, substrate sheet 54 may have second through-holes 541, and cover sheet 56 may have third through-holes 561. The positions of the first through hole 521, the second through hole 541 and the third through hole 561 may correspond to each other. The light emitting element 58 may be disposed on the light source circuit board 62 at a position corresponding to the first through hole 521, the second through hole 541 and the third through hole 561. The bottom plate 25 of the key 12 may have a hole 221 corresponding to the first through hole 521, the second through hole 541 and the third through hole 561, and the light emitting element 58 disposed on the light source circuit board 62 may pass through the hole 221 and enter the channel formed by the hole 221, the first through hole 521, the second through hole 541 and the third through hole 561, so that the extending directions of the light emitting element 58 and the channel may be aligned with the long axis direction of the light guide 60. There may be a partition 11 between the fan unit 14 and the backlight module 16G, and in order to make the light guide 60 extend into the fan unit 14 and further project the incident light B to the fan unit 14 through the light guide 60, the partition 11 and the fan housing 143 may be respectively provided with holes to correspondingly receive the light guide 60. If necessary, the light-emitting element 58 and the light source circuit board 62 may not be fixed on the bottom board 25, but are directly disposed on the surface of the cover sheet 56 (adjacent to the side of the key 12), that is, the light-emitting element 58 and the light source circuit board 62 are disposed between the cover sheet 56 and the bottom board 25, in short, the light-emitting element 58 (the second light source) penetrates the first through hole 521 of the light guiding sheet 52 along the second direction D2, and the other light-emitting element (the first light source) still provides light to illuminate the key 12 through the light guiding sheet 52 towards the first direction D1. In this embodiment, the first light source (not shown) and the second light source (the light emitting element 58) may be located on the lower surface of the light source circuit board 62 (above the direction of the key 12 or the first direction D1).

The light pipe 60 is adjacent to the light emitting member 58 along the second direction D2 and may have a first end 601 and a second end 602 opposite to each other. The first end 601 may be directed to the light emitting member 58, and the second end 602 may extend out of the substrate 54 of the backlight module 16G and extend into the fan unit 14. Therefore, the incident light B output from the light emitting element 58 enters the light guide 60 from the first end 601, and is projected out from the second end 602 by the total internal reflection of the light guide 60. In the seventh embodiment, the second end 602 of the light pipe 60 can extend between the fan blade 141 and the motor 142 of the fan unit 14 to provide illumination and decoration effects. The light pipe 60 can be fixed to the fan housing 143 or the fan circuit board 144 of the fan unit 14, and its position depends on the design requirement.

Referring to fig. 11, fig. 11 is a schematic view of a backlight module 16H (16) according to an eighth embodiment of the invention. In the eighth embodiment, the components having the same component names or component numbers as those in the other embodiments of the present invention have the same structures and functions, and description thereof is not repeated. The backlight module 16H is adjacent to the fan unit 14 with a partition 64 therebetween. The backlight module 16H may include a light source circuit board 66, a first light source (not shown), a light emitting element 68 (a second light source), a buffer sheet 70 (if necessary), and a light guide 72. The partition 64 may have a first light transmission region 641. The light source circuit board 66 and the fan unit 14 are disposed on opposite sides of the partition 64, respectively. The buffer sheet 70 may be disposed between the partition 64 and the light source circuit board 66 to heighten the receiving space for the protruded luminous member 68; in addition, the buffer sheet 70 may have a second light-transmitting region 701 through which the light emitting member 68 penetrates. The light emitting member 68 may be disposed on the light source circuit board 66 at a position corresponding to the first light transmission region 641 of the partition 64 and the second light transmission region 701 of the buffer sheet 70. The light pipe 72 may be disposed between the light emitter 68 and the fan unit 14. The light guide sheet 26/34 (the first light guide sheet) in the foregoing embodiment may also be used as the buffer sheet 70 to make the buffer sheet 70 serve as the second light guide sheet to provide the function of lateral light transmission, and the light is guided toward the second direction D2 by using the light reflection structure 261, the cover sheet 28/36/44/56, and the substrate sheet 30/38/46/54 in the foregoing embodiment, or by directly coating the light reflection ink or the opaque ink on the buffer sheet 70.

The position of the light guide 72 may correspond to the first light-transmitting region 641 of the partition 64 and the second light-transmitting region 701 of the buffer sheet 70. The light pipe 72 may have opposite first and second ends 721, 722. The first end 721 may be directed toward the light emitting member 68, and the second end 722 may extend into the interior of the fan unit 14. The incident light B output by the light emitting element 68 can enter the light guide tube 72 from the first end 721, and then be projected out from the second end 722 by the total internal reflection of the light guide tube 72 to illuminate the fan unit 14, thereby providing illumination and decoration effects. The light pipe 72 can be fixed to the fan housing 143 or the fan circuit board 144 of the fan unit 14, and the position of the light pipe depends on the design requirement. The first light-transmitting region 641 and the second light-transmitting region 701 can be through holes for the light-emitting element 68 and the light guide 72 to penetrate.

Referring to fig. 12, fig. 12 is a schematic view of a backlight module 16I (16) according to a ninth embodiment of the invention. In the ninth embodiment, the elements having the same element names or element numbers as those in the other embodiments of the present invention have the same structures and functions, and description thereof is not repeated. The backlight module 16I may include a light source circuit board 66, a light emitting member 68, and a buffer sheet 70. The light emitting member 68 may be disposed on the light source circuit board 66. The light source circuit board 66 may be disposed on the side of the partition 64 opposite the fan unit 14. The separating member 64 may have a first light-transmitting region 641, such as a through hole or a solid light-transmitting material, which is located adjacent to the light-emitting member 68. The separating member 64 may also have a bending region 642 for shielding a portion of the light emitting member 68. The buffer sheet 70 may be disposed between the partition 64 and the light source circuit board 66. The second light-transmitting region 701 of the buffer sheet 70 may be a bump structure for covering the light emitting member 68. As in the previous embodiment, the light guide sheet 26/34 (the first light guide sheet) in the previous embodiment may also be used as the buffer sheet 70 to provide the light lateral transmission function, and the light reflection structure 261, the cover sheet 28/36/44/56, and the substrate sheet 30/38/46/54 in the previous embodiment are used to guide the light toward the second direction D2 by directly coating the light reflection ink or the opaque ink on the buffer sheet 70. The buffer sheet 70 may have a light transmission or light transmission property in its entirety, or only the second light transmission region 701 may have a light transmission or light transmission property.

The light source circuit board 66 may have a reflective ink coating layer positioned adjacent to the light emitting member 68 for reflecting the incident light B output by the light emitting member 68 to be projected in the direction of the first light transmission area 641 or the second direction D2. The incident light B from the light emitting element 68 can pass through the second transparent region 701 and be projected to the fan unit 14 through the first transparent region 641. The reflective action of the reflective ink coating 72 may enhance the intensity of light projected onto the fan unit 14, providing illumination and decorative effects.

Referring to fig. 13, fig. 13 is a schematic view of a backlight module 16J (16) according to a tenth embodiment of the invention. In the tenth embodiment, the components having the same component names or component numbers as those in the other embodiments of the present invention have the same structures and functions, and description thereof is not repeated. The difference between the tenth embodiment and the ninth embodiment is mainly that the bending region 642 of the partition 64 of the backlight module 16J is used to shield all the light emitting members 68, and the backlight module 16J further includes the light guiding fins 74 and the abutting members 76 cut out from the buffer sheet 70. The open end of the light guide tab 74 corresponds to the inside of the second light-transmitting section 701 of the buffer sheet 70. One end of the light guide tab 74 is directed to the light emitting element 68, and the open end of the light guide tab 74 is bent to be directed to the first light-transmitting area 641 or to the second direction D2 due to the abutting of the abutting element 76. The incident light B output by the light-emitting element 68 can be projected to the fan unit 14 through the total internal reflection of the light guide fins 74, i.e., the backlight module 16J changes the light transmission direction of the incident light B by the bending of the light guide fins 74.

In addition, the backlight module 16J may further include a reflective material 78 disposed on the light emitting member 68. The reflective material 78 provides a light recycling function. If the incident light B from the light emitting element 68 can be reflected back to the light guiding fins 74, the intensity of the illuminating light can be increased to improve the illumination and decoration effect. The buffer sheet 70 of the tenth embodiment may be made of a light guide material, and the light guide fins 74 may be buffer fins formed by partially cutting the buffer sheet 70; alternatively, if the buffer sheet 70 does not have a light guiding property, the light guiding fins 74 may be a separate element additionally installed. The corresponding structural relationship between the buffer sheet 70 and the light guide fins 74 is not limited to the above-mentioned embodiments, and may be determined according to the design requirement.

It should be added that the backlight module 16G/16H/16I in fig. 11, 12, and 13 may also not include the first light source (and the light guide sheet/the cover sheet/the substrate sheet/the light reflecting structure/the ink, etc.) to provide the illumination in the first direction D1, and is used for the illumination of the fan unit 14 alone.

Referring to fig. 15 and 16, fig. 15 is a bottom side view of a computing device 2 and a protective cover 200 according to an eleventh embodiment of the invention, and fig. 16 is a partial structural sectional view of the keyboard 10A and the protective cover 200 of fig. 15 along a line B-B'. In the eleventh embodiment, the elements having the same element names or element numbers as those in the other embodiments of the present invention have the same structures and functions, and description thereof is not repeated. The backlight module 16K (16) capable of emitting light in multiple directions can be applied to a tablet computer and a protective sleeve keyboard. In fig. 15, the keyboard 10A is embedded between the upper casing 200A and the lower casing 200B of the protective cover 200, as shown in fig. 1A, such that the plurality of keys 12 are exposed outside the upper casing 200A. The backlight module 16K is disposed between the lower portion of the keyboard 10A and the lower casing 200B, that is, the backlight module 16K is disposed between the plurality of keys 12 (or the keyboard 10A) and the protective cover 200 (the lower casing 200B), or the backlight module 16K is adjacent to the protective cover 200 (the lower casing 200B) along the second direction D2. The computing device 2 (e.g., a tablet computer) is accommodated in the extension case 200C of the protective cover 200, and the extension case 200C may be fixed to the case of the computing device 2 itself only by magnetism without covering the computing device 2. The protective cover 200 can define the light transmitting portion 201 on the lower case 200B, for example, a single or multiple light transmitting structures are formed on the second direction D2 as the light transmitting portion 201 by hollowing or carving, and the position of the light transmitting portion 201 corresponds to the second light transmitting area 302 of the substrate sheet 30 to form the light-emitting decoration pattern. The design position of the light transmitting portion 201 and/or the second light transmitting portion 302 is not limited to the above-mentioned embodiments, and one or both of them can be defined as a brand mark, a function indication (e.g. incoming call/power) pattern, etc. according to the actual requirement.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.

In summary, the backlight module of the present invention emits light in the first direction and the second direction opposite to each other. The backlight module comprises a light guide plate, a covering sheet, a substrate sheet and a light emitting piece. The cover sheet is disposed on the top side of the light guide sheet along the first direction. The cover sheet defines a plurality of first light-transmitting regions. The first light-transmitting areas correspond to the keys respectively. The substrate sheet is arranged on the bottom side of the light guide sheet along the second direction. The substrate sheet defines at least one second light-transmitting region. The light emitting part outputs incident light to enter the light guide sheet, after entering the light guide sheet, a first part of the incident light is transmitted from the plurality of first light transmission areas to the first direction through the light guide sheet, and a second part of the incident light is transmitted from the second light transmission areas to the second direction through the light guide sheet. The invention can guide the illumination light of the backlight module in the keyboard to irradiate different directions to be used for illuminating adjacent parts at different positions, and achieves the decoration or indication function of double-sided backlight on the premise of not greatly increasing the integral thickness of the device.

The present invention is capable of other embodiments, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A backlight module, wherein the backlight module emits light in a first direction and a second direction opposite to each other, the backlight module is adjacent to a plurality of keys along the first direction, the backlight module comprises:

a light guide sheet;

2. The backlight module of claim 1, wherein the cover sheet has at least one first cover layer defining the first transparent region, the at least one first cover layer comprises an opaque ink layer and/or a reflective ink layer, and the at least one first cover layer does not comprise the opaque ink layer or the reflective ink layer in the first transparent region.

3. The backlight module of claim 1, wherein the substrate has at least one second cover layer defining the at least one second transparent region, the at least one second cover layer comprises a light-blocking ink layer and/or a light-reflecting ink layer, and the at least one second cover layer does not comprise the light-blocking ink layer or the light-reflecting ink layer in the at least one second transparent region.

4. The backlight module of claim 1, wherein the light guide plate has a plurality of sets of light reflecting structures;

5. The backlight module of claim 1, wherein the light guide plate has a hole, the cover plate has a plurality of protrusions, and the protrusions have bent sections inserted into the hole, so that the inner surfaces of the protrusions reflect the second portion of light toward the at least one second light-transmitting region.

6. The backlight module of claim 5, wherein the cover sheet has at least one first cover layer, the at least one first cover layer comprising a reflective ink layer, the reflective ink layer coated on the plurality of protrusions, respectively.

7. The backlight module of claim 1, wherein the backlight module is adjacent to a protective cover along the second direction, the protective cover having at least one light transmissive portion corresponding to the at least one second light transmissive region of the substrate sheet.

8. The backlight module of claim 1, wherein the backlight module is adjacent to a fan unit along the second direction, and the at least one second light-transmissive region corresponds to the fan unit.

9. The backlight module of claim 1, wherein the light guide plate comprises a U-shaped slot to define a light guide plate, at least a portion of the light exit section of the light guide plate is exposed to the bottom side of the light guide plate, so that the second portion of light is partially irradiated toward the second direction.

10. The backlight module of claim 9, further comprising a supporting member, wherein the supporting member supports the light guide plate to tilt an included angle toward the second direction, so that at least a portion of the light-emitting section of the light guide plate is exposed to the bottom side of the light guide plate.

11. The backlight module as claimed in claim 10, wherein the cover sheet has a cover tab covering the light guide tab of the light guide sheet, and the abutting member abuts against the cover tab and the light guide tab to tilt in the second direction.

12. A backlight module, comprising:

the light guide plate is provided with at least one first through hole;

13. The backlight module of claim 12, wherein the backlight module is adjacent to the plurality of keys along a first direction, the light-emitting member comprises a first light source and a second light source, the first light source illuminates the plurality of keys through the light guide plate toward the first direction, and the second light source penetrates the at least one first aperture of the light guide plate along the second direction.

14. The backlight module of claim 12, wherein the backlight module is disposed adjacent to a fan unit along the second direction, and the second end of the light pipe is disposed in the fan unit.

15. A backlight module adjacent to a fan unit along a second direction, the backlight module and the fan unit being respectively disposed at opposite sides of a partition, the partition having at least one first light-transmitting region, the backlight module comprising:

16. The backlight module of claim 15, further comprising a light pipe having a first end and a second end opposite to each other, wherein the first end is directed to the light emitting element, and the second end extends into the fan unit.

17. The backlight module of claim 15, wherein the buffer sheet has at least one ridge structure to cover the light emitting member.

18. The backlight module of claim 15, further comprising a supporting member and a light guiding fin on the buffer sheet, wherein one end of the light guiding fin is directed to the light emitting member, and the supporting member supports and bends the open end of the light guiding fin to the second direction.