Backlight module

Abstract

The present invention provides a backlight module, which is suitable for being disposed under a bracket of a key structure. The backlight module includes a reflector, a light guide plate, and a composite light-emitting layer. The light guide plate is disposed on the reflector. The composite light-emitting layer is disposed on the light guide plate, includes a first light source and a first circuit, and has a light-shielding pattern. The first light source is electrically connected to the first circuit. The light guide plate has a plurality of microstructures, which are disposed on a surface of the light guide plate away from the first light source. The first light source does not protrude from the upper surface of the bracket, and the first light source is disposed directly below a keycap of the key structure.

Description

[0001] This invention is a divisional application of the patent application with the application number 201910623300.8 and the invention title "Luminescent Keyboard and Backlight Module" filed on July 11, 2019. Technical Field

[0002] This invention relates to a backlight module, and particularly to a thinned backlight module. Background Art

[0003] With the development of technology, the appearance of products tends to be lightweight and thin, and more and more emphasis is placed on visual stimulation. Taking keys as an example, currently, designers have designed luminescent keys to increase aesthetics or recognition. The luminescent key mainly sets a backlight module below the key structure, and how to make the backlight module provide more diverse optical effects or thin the backlight module is the current research direction. Summary of the Invention

[0004] This invention provides a backlight module with a smaller thickness.

[0005] A luminescent keyboard of this invention can present diverse backlight effects.

[0006] A luminescent keyboard of this invention includes a bracket, keycaps, a circuit layer, a light guide plate, and a composite light-emitting layer. The bracket has at least one opening. The keycaps are arranged on the bracket and connected to the bracket by a support component. The circuit layer is arranged between the keycaps and the bracket. The light guide plate is arranged under the bracket. The composite light-emitting layer is arranged under the bracket and has a light-shielding pattern. The composite light-emitting layer includes a light-transmitting substrate, a first circuit, a first light source, and a first protective layer. The first circuit is arranged on one side of the light-transmitting substrate. The first light source is arranged on one side of the light-transmitting substrate and is electrically connected to the first circuit. The first protective layer covers the first circuit, and at least part of the first circuit is located between the first protective layer and the light-transmitting substrate.

[0007] In an embodiment of this invention, it further includes a reflector arranged under the bracket, and the light guide plate is arranged between the composite light-emitting layer and the reflector.

[0008] In an embodiment of this invention, the above light-shielding pattern has a light-transmitting area corresponding to the keycaps, and the first light source is located in the light-transmitting area.

[0009] In an embodiment of this invention, the above composite light-emitting layer further includes a light-shielding plate, which is arranged between the light-transmitting substrate and the light guide plate or between the bracket and the light-transmitting substrate, and the light-shielding pattern is formed on the light-shielding plate.

[0010] In an embodiment of the present invention, the above-mentioned illuminated keyboard further includes a second light source and a circuit board, which are disposed under the composite light-emitting layer. The second light source passes through the light guide plate and is electrically connected to the circuit board located under the light guide plate, and the first circuit of the composite light-emitting layer is electrically connected to the circuit board.

[0011] In an embodiment of the present invention, the above-mentioned composite light-emitting layer further includes a second circuit, a second light source, and a second protective layer. The second circuit is disposed on one side of the light-transmissive substrate. The second light source is disposed on one side of the light-transmissive substrate and is electrically connected to the second circuit. The second protective layer covers the second circuit, and at least a part of the second circuit is located between the second protective layer and the light-transmissive substrate, and the light-shielding pattern is configured corresponding to the first light source.

[0012] In an embodiment of the present invention, the above-mentioned first light source and the second light source are located on the same side of the light-transmissive substrate, and the first light source emits light toward the light guide plate.

[0013] In an embodiment of the present invention, the above-mentioned first light source and the light guide plate are located on opposite sides of the light-transmissive substrate, and the first light source is disposed within the opening of the bracket.

[0014] In an embodiment of the present invention, the above-mentioned first light source and the light guide plate are located on the same side of the light-transmissive substrate, and the light guide plate has holes, and the first light source is disposed corresponding to the holes.

[0015] In an embodiment of the present invention, the above-mentioned keycap has at least one light-transmissive portion, and the first light source is disposed corresponding to the light-transmissive portion.

[0016] In an embodiment of the present invention, the above-mentioned light guide plate is disposed between the bracket and the composite light-emitting layer, and the first light source and the light guide plate are located on the same side of the light-transmissive substrate.

[0017] In an embodiment of the present invention, the above-mentioned first light source and the light-shielding pattern are located on opposite sides of the light-transmissive substrate, the light-shielding pattern completely covers the lower surface of the light-transmissive substrate, and the first protective layer has reflectivity.

[0018] In an embodiment of the present invention, the first circuit of the above-mentioned composite light-emitting layer includes printed conductive ink or a patterned metal layer, and the first circuit is located below the non-opening area of the bracket.

[0019] In an embodiment of the present invention, the above-mentioned first light source includes a plurality of light-emitting diodes, and each light-emitting diode emits light of a different wavelength.

[0020] In an embodiment of the present invention, the above-mentioned light guide plate has a plurality of microstructures, and these microstructures are disposed on the lower surface of the light guide plate corresponding to the openings of the bracket.

[0021] A backlight module of the present invention is adapted to be disposed under a key structure. The backlight module includes a reflector, a light guide plate, and a composite light-emitting layer. The light guide plate is disposed on the reflector. The composite light-emitting layer is disposed on the light guide plate, includes a first light source, and has a light-shielding pattern. The light guide plate has a plurality of microstructures disposed on a surface of the light guide plate away from the first light source.

[0022] In an embodiment of the present invention, the above-mentioned composite light-emitting layer includes a light-transmissive substrate, a first circuit disposed on the light-transmissive substrate, and a light-shielding plate. The first light source is disposed on the light-transmissive substrate and electrically connected to the first circuit. The light-shielding plate is located between the light guide plate and the light-transmissive substrate or between the key structure and the light-transmissive substrate, and the light-shielding pattern is formed on the light-shielding plate.

[0023] In an embodiment of the present invention, the above-mentioned backlight module further includes a circuit board and a second light source. The circuit board is disposed under the reflector. The second light source is disposed and electrically connected to the circuit board, passes through the reflector and extends beside the light guide plate, and the first circuit is electrically connected to the circuit board.

[0024] In an embodiment of the present invention, the above-mentioned composite light-emitting layer includes a light-shielding plate disposed on the light guide plate and a first circuit disposed on the light-shielding plate. The first light source is disposed on the light-shielding plate and electrically connected to the first circuit.

[0025] In an embodiment of the present invention, the above-mentioned light guide plate has holes. The first light source is disposed on a surface of the light-shielding plate facing the light guide plate and corresponding to the holes, and the position of the first light source on the light-shielding plate corresponds to the light-shielding pattern.

[0026] In an embodiment of the present invention, the above-mentioned composite light-emitting layer has a light-transmissive area not covered by the light-shielding pattern. The first light source is disposed on a surface of the light-shielding plate facing the light guide plate or the reflector corresponding to the light-transmissive area.

[0027] In an embodiment of the present invention, the above-mentioned first light source is disposed on a surface of the light-shielding plate facing away from the light guide plate.

[0028] In an embodiment of the present invention, the above-mentioned first circuit is located at a position corresponding to the light-shielding pattern.

[0029] In an embodiment of the present invention, the above-mentioned composite light-emitting layer includes a light-transmissive substrate and a first circuit disposed on the light-transmissive substrate. The first light source is disposed on the light-transmissive substrate and electrically connected to the first circuit. The first light source and the light guide plate are on the same side of the light-transmissive substrate, and the first light source and the light-shielding pattern are on opposite sides of the light-transmissive substrate.

[0030] Based on the above, the light-emitting keyboard of the present invention has a composite light-emitting layer disposed under a bracket. The backlight module of the present invention also has a composite light-emitting layer disposed under a key structure. The first light source is integrated in the composite light-emitting layer, so that the backlight module has a smaller thickness. Description of the Drawings

[0031] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present invention and, together with the description, are used to explain the principles of the present invention.

[0032] Figure 1A is a top view of a backlit keyboard according to an embodiment of the present invention;

[0033] Figure 1B is Figure 1A an exploded view of the backlight module of the backlit keyboard;

[0034] Figure 1C is Figure 1B a partial cross-sectional view of the backlight module disposed below the key structure;

[0035] Figure 2A is an exploded view of a backlight module according to another embodiment of the present invention;

[0036] Figure 2B is Figure 2A a partial cross-sectional view of the backlight module;

[0037] Figure 2C is Figure 2A a partial view of the composite light-emitting layer of the backlight module;

[0038] Figure 2D is Figure 2A a positional relationship diagram between the first light source, the first circuit and the bracket of the key structure of the backlight module;

[0039] Figure 3 is a partial cross-sectional view of a backlight module according to another embodiment of the present invention;

[0040] Figure 4A is an exploded view of a backlight module according to another embodiment of the present invention;

[0041] Figure 4B is Figure 4A a partial cross-sectional view of the backlight module;

[0042] Figure 4C is Figure 4A a cross-sectional view of another part of the backlight module;

[0043] Figures 5 to 7 is a partial cross-sectional view of various backlight modules according to other embodiments of the present invention.

[0044] Explanation of the reference numerals in the drawings

[0045] 5: Backlit keyboard;

[0046] 10: Button structure;

[0047] 11: Keycap;

[0048] 11a: Light-transmitting part;

[0049] 12: Support component;

[0050] 13: Elastomer;

[0051] 14: Circuit layer;

[0052] 15: Bracket;

[0053] 16, 18, 114, 126: Opening;

[0054] 17: Conductive part;

[0055] 100, 100a, 100b, 100c, 100c1, 100d, 100e, 100f: Backlight module;

[0056] 110: Reflector;

[0057] 111, 131: Light-transmitting substrate;

[0058] 112: First circuit;

[0059] 120, 120e: Light guide plate;

[0060] 122, 123: Hole;

[0061] 124: Microstructure;

[0062] 130, 130a, 130c1, 130d: Composite light-emitting layer;

[0063] 132: Extension end;

[0064] 133: Light-shielding pattern;

[0065] 134: Light-shielding plate;

[0066] 135: Film;

[0067] 136: Reflective coating;

[0068] 117, 137: Light-shielding coating;

[0069] 138: Light-transmitting area;

[0070] 139: First circuit;

[0071] 140, 141, 170: First light source;

[0072] 142, 172: First protective layer;

[0073] 143, 144, 145: Light-emitting diodes;

[0074] 150: Circuit board;

[0075] 152: Connector;

[0076] 160, 180, 181: Second light sources;

[0077] 182: Second circuit;

[0078] 184: Second protective layer. Detailed implementation manners

[0079] Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same component symbols are used in the drawings and the description to represent the same or similar parts.

[0080] Figure 1A is a top view of a light-emitting keyboard according to an embodiment of the present invention. Figure 1B is Figure 1A an exploded schematic view of the backlight module of the light-emitting keyboard.

[0081] Please refer to Figure 1A and Figure 1B , the light-emitting keyboard 5 of this embodiment includes at least one key structure 10 and a backlight module 100 located below these key structures 10. The backlight module 100 provides light sources so that light can irradiate the back of these key structures 10, bringing instructions or diverse visual effects to the user. Figure 1A The illustrated light-emitting keyboard 5 takes the keyboard of a notebook computer as an example for illustration, but the present invention does not limit the type of the light-emitting keyboard.

[0082] Figure 1C is Figure 1B a partial cross-sectional schematic view of the backlight module disposed below the key structure. It should be noted that, in order to clearly show the detailed structure of the backlight module, only a single key structure 10 is schematically shown in Figure 1C . The size ratio between the key structure 10 and the backlight module 100 is only for illustration, and the types and quantities of the key structures 10 are not limited thereby.

[0083] As shown in Figure 1CAs shown, in this embodiment, the key structure 10 includes a keycap 11, a support assembly 12, an elastomer 13, a circuit layer 14, and a bracket 15. The bracket 15 is disposed on the backlight module 100 for carrying the keycap 11, the support assembly 12, the elastomer 13, and the circuit layer 14. In this embodiment, the bracket 15 may have a plurality of openings (such as perforations) for allowing light to pass through or for accommodating a light source. For example, the light from the backlight module 100 can pass through the openings 16 and 18 upward through the bracket 15 and irradiate the back of the keycap 11. The opening 16 can also accommodate the first light source 140 of the backlight module 100, but the number and arrangement of the openings of the bracket 15 are not limited thereto.

[0084] The circuit layer 14 is disposed between the keycap 11 and the bracket 15. The circuit layer 14 is, for example, a flexible thin-film circuit with a multi-layer stacked structure, which has a conduction portion 17 as a switching area for triggering a signal. The elastomer 13 is disposed between the keycap 11 and the circuit layer 14 to provide a restoring force for the keycap 11 to return to its original position before being pressed. The support assembly 12 is disposed between the keycap 11 and the bracket 15. The two ends of the support assembly 12 are respectively movably connected to the keycap 11 and the bracket 15, so that the keycap 11 can move smoothly up and down relative to the bracket 15 through the connection of the support assembly 12. The support assembly 12 is, for example, a scissor-foot structure, but is not limited thereto.

[0085] The above-mentioned elastomer 13 is located on the circuit layer 14 corresponding to the conduction portion 17, wherein the elastomer 13 has a triggering portion correspondingly disposed above the conduction portion 17. When the keycap 11 is pressed, the elastomer 13 is squeezed and deformed, and then the triggering portion moves downward and presses on the conduction portion 17 on the circuit layer 14 to turn on the switch and generate a pressing signal; when the force pressing the keycap 11 is removed, the elastic restoring force of the elastomer 13 drives the keycap 11 to return upward to its original position. In this embodiment, the keycap 11 may also have a light-transmitting portion 11a, which is defined by at least one character represented by each key structure 10, for example, for the light emitted by the backlight module 100 to pass through, and thus become a light-emitting key for the user to identify.

[0086] The backlight module 100 disposed below the key structure 10 includes a reflector 110, a light guide plate 120, and a composite light-emitting layer 130 stacked from bottom to top. The composite light-emitting layer 130 is disposed between the bracket 15 and the light guide plate 120, and the light guide plate 120 is disposed between the composite light-emitting layer 130 and the reflector 110. As Figure 1BAs shown, the composite light-emitting layer 130 located on the light guide plate 120 has a light-shielding pattern 133, which can shield the areas that do not need light irradiation or passage to avoid light leakage. The composite light-emitting layer 130 also has a light-transmitting area 138, which is, for example, an area not covered by the light-shielding pattern 133, allowing light to pass through to achieve the key backlight effect. In one embodiment, to avoid light leakage between the key structures 10, a light-shielding pattern 133 can be provided below the adjacent two keycaps 11, and the area surrounded by the light-shielding pattern 133 is the light-transmitting area 138. The position of the light-transmitting area 138 corresponds to the position of the keycaps 11 of the key structures 10 on the illuminated keyboard 5( Figure 1A )

[0087] In this embodiment, the composite light-emitting layer 130 includes a light-transmitting substrate 131 and a light-shielding plate 134 located below the light-transmitting substrate 131. A first circuit 139, a first light source 140, and a first protective layer 142 are provided on the light-transmitting substrate 131. The first circuit 139 and the first light source 140 are disposed on one side of the light-transmitting substrate 131, and the first light source 140 is electrically connected to the first circuit 139. The first circuit 139 includes printed conductive ink or a patterned metal layer, which is, for example, a silver paste wire or a copper foil wire, but the type of the first circuit 139 is not limited thereto. After the first circuit 139 is formed on the upper surface of the light-transmitting substrate 131, the first light source 140 is disposed on the upper surface of the light-transmitting substrate 131 so that the electrodes of the first light source 140 are electrically connected to the first circuit 139. That is to say, the light-transmitting substrate 131 and the first circuit 139 on the light-transmitting substrate 131 serve as a circuit board for supplying power to the first light source 140. The first protective layer 142 covers the first circuit 139, so that at least a part of the first circuit 139 is located between the first protective layer 142 and the light-transmitting substrate 131, avoiding damage to the circuit pattern on the light-transmitting substrate 131 and causing an open circuit or a short circuit. In this embodiment, the first protective layer 142 can also extend to cover the first light source 140, protecting both the first circuit 139 and the first light source 140 at the same time. The first protective layer 142 is, for example, a flexible plastic film, and its thickness is less than the thickness of the light-transmitting substrate 131.

[0088] As Figure 1B and Figure 1CAs shown, the light-shielding plate 134 is located between the light guide plate 120 and the light-transmissive substrate 131, and the light-shielding pattern 133 defines a light-transmissive area 138 on the light-shielding plate 134. The light-shielding plate 134 includes a film 135 and the light-shielding pattern 133 formed on the surface of the film 135. In this embodiment, the film 135 is a light-transmissive substrate, and the light-shielding pattern 133 includes a reflective coating 136 and a light-shielding coating 137 laminated on one side of the light-transmissive substrate. When the light transmitted in the light guide plate 120 hits the reflective coating 136 of the light-shielding pattern 133, it can be reflected back into the light guide plate 120 for continuous transmission, and the light-shielding coating 137 can prevent the light from emitting from the light-shielding pattern 133. In this embodiment, the reflective coating 136 is, for example, white paint, and the light-shielding coating 137 is, for example, black paint. Of course, the form of the light-shielding pattern 133, the types and colors of the reflective coating 136 and the light-shielding coating 137 are not limited thereto.

[0089] In this embodiment, the first light source 140 is disposed on the surface of the light-transmissive substrate 131 facing away from the light-shielding plate 134. The first light source 140 is, for example, a top view light source. By disposing the first light source 140 corresponding to the light-transmissive portion 11a of the keycap 11 within the opening 16 of the bracket 15, and the first light source 140 does not protrude from the upper surface of the bracket 15, the light emitted by the first light source 140 below the key is adapted to emit in a direction away from the light-shielding plate 134, and can directly pass through the key structure 10 to provide a high-brightness and high-directivity optical effect, thereby realizing independent lighting of a single key. In addition, in other embodiments, the stacking positions of the light-shielding plate 134 and the light-transmissive substrate 131 can also be interchanged, such that the light-shielding plate 134 is located between the bracket 15 and the light-transmissive substrate 131, as long as the light of the first light source 140 is not blocked by the light-shielding pattern 133 of the light-shielding plate 134 above it.

[0090] In addition, the backlight module 100 further includes a circuit board 150 and a second light source 160. The circuit board 150 is located below the reflector 110, such that the reflector 110 is located between the circuit board 150 and the light guide plate 120. The circuit board 150 is, for example, a flexible circuit board and is electrically connected to a power source to supply power to the second light source 160. The second light source 160 is disposed under the composite light-emitting layer 130. The second light source 160 passes through the light guide plate 120 and the reflector 110 and is electrically connected to the circuit board 150 below. For example, the reflector 110 and the light guide plate 120 respectively have corresponding openings 114 and 126. The second light source 160 is disposed in the openings 114 and 126 and extends upward from the circuit board 150 to one side of the light guide plate 120. The second light source 160 is, for example, a side view light source. The light emitted by the second light source 160 is adapted to enter the light guide plate 120 for total reflection, so that the light emitted by the second light source 160 is evenly distributed throughout the backlight module 100 and is emitted upward from the light-transmitting area 138 of the light-shielding plate 134, thereby providing an optical effect of brightness uniformity.

[0091] The above-mentioned first light source 140 and the second light source 160 can be respectively different types of light-emitting diodes. In this embodiment, the first light source 140 can select a light-emitting diode without a bracket and a substrate. The die of the light-emitting diode is disposed on the light-transmitting substrate 131 in a flipchip manner, and the positive and negative electrodes of the chip are connected to the first circuit 139 by soldering or surface mounting technology. Then, dispensing can be selectively performed (phosphor can be mixed in the glue according to the requirement of the light-emitting color), so that the light-transmitting resin coats the chip to provide protection or light mixing function. Compared with the thickness of the bracket-packaged light-emitting diode of about 0.6 millimeters (mm), the miniaturized first light source 140 in this embodiment adopts chip-level packaging without additional brackets and wire bonding, and the thickness can be as low as less than 0.08 millimeters. Furthermore, using printed conductive ink or patterned metal foil as the circuit layer of the first light source 140, its thickness is much smaller than that of a general circuit board (about 0.15 millimeters to 0.2 millimeters). Therefore, integrating the first light source 140 into the composite light-emitting layer 130 enables the backlight module 100 to achieve a thinning effect. Of course, the thickness comparison of the above-mentioned components and the drawings are only schematically illustrative of the relative positions and thickness relationships and are not limited thereto.

[0092] In this embodiment, the second light source 160 of the backlight module 100 is, for example, a side-emitting light source. The backlight module 100 can make the light emit comprehensively and uniformly from these keys on the illuminated keyboard 5 through the second light source 160, the reflector 110, and the light guide plate 120. In addition, the first light source 140 of the backlight module 100 is, for example, a front-emitting light source. For the keys with special functions on the illuminated keyboard 5, the backlight module 100 can provide a local illumination and independently dimmable optical effect by arranging the first light source 140 below such keys, so that users can quickly find this key visually.

[0093] Of course, the form of the backlight module of the present invention is not limited to the above-mentioned backlight module 100. The following embodiments will introduce other types of backlight modules. Except for explaining the main differences, the same or similar components as those in the previous embodiment are denoted by the same or similar symbols and will not be described in detail. In addition, in order to clearly show the detailed structure of the backlight module, the key structure will be omitted in the drawings of the backlight module. However, it should be understood that the backlight module of the following embodiments is suitable for being arranged below the key structure to provide a key backlight visual effect.

[0094] Figure 2A is an exploded schematic view of a backlight module according to another embodiment of the present invention. Figure 2B is Figure 2A a partial cross-sectional schematic view of the backlight module. Please refer to Figure 2A and Figure 2B In this embodiment, the composite light-emitting layer 130a of the backlight module 100a includes a light-shielding plate 134 arranged on the light guide plate 120 and a first circuit 139 arranged on the light-shielding plate 134. The first light source 140 is arranged on the light-shielding plate 134 and electrically connected to the first circuit 139. That is to say, the light-shielding plate 134 and the first circuit 139 on the light-shielding plate 134 serve as the circuit board of the first light source 140. Compared with Figure 1B and Figure 1C the embodiment shown, the composite light-emitting layer 130a of this embodiment can omit the light-transmitting base material 131 of the composite light-emitting layer 130, and thus can reduce the overall thickness. The original first circuit 139, first light source 140, and first protective layer 142 on the light-transmitting base material 131 shown in Figure 1C will be directly arranged on the surface of the film 135 (such as a light-transmitting base material) of the light-shielding plate 134 in this embodiment.

[0095] In this embodiment, the first light source 140 and the light guide plate 120 are located on opposite sides of the light-transmitting film 135, that is, the first light source 140 is arranged on the surface of the light-shielding plate 134 facing away from the light guide plate 120. When the key structure is paired with the backlight module 100a, the first light source 140 can utilize, for example, Figure 1CThe bracket 15 shown has an opening 16 as an accommodation space. The light emitted by the first light source 140 is adapted to be emitted upward in a direction away from the light guide plate 120, so as to provide a high-brightness and high-directivity optical effect for the independent key. The light emitted by the second light source 160 is adapted to enter the light guide plate 120 and is emitted from the light-transmitting area 138 of the light-shielding plate 134, and can provide an optical effect of overall brightness uniformity.

[0096] In addition, in the composite light-emitting layer 130a, the first circuit 139 provided on the light-shielding plate 134 is electrically connected to the circuit board 150. The first circuit 139 at the extending end 132 of the composite light-emitting layer 130a is connected to the circuit of the circuit board 150, for example, by soldering or hot pressing. That is to say, in this embodiment, even if the first light source 140 and the second light source 160 are located on different layers, they can be connected to the same power supply through the circuit board 150, so that the same power supply can supply power to the first light source 140 and the second light source 160, thereby simplifying the circuit design and enabling independent control of the light emission of the first light source 140 and the second light source 160. Of course, in other embodiments, the first light source 140 and the second light source 160 can also be connected to different power supplies, that is, the first circuit 139 of the first light source 140 may not be connected to the circuit board 150.

[0097] Figure 2C is Figure 2A A partial schematic view of the composite light-emitting layer of the backlight module. Figure 2D is Figure 2A A positional relationship diagram between the first light source, the first circuit, and the bracket of the key structure of the backlight module. Please refer to Figure 2C , the first light source 140 corresponding to a single key structure is located at a position corresponding to the light-transmitting area 138, and the first circuit 139 coupling the first light source 140 on the light-shielding plate 134 is distributed along the light-shielding pattern 133 on the light-shielding plate 134 to connect to the power supply. Please refer to Figure 2D , in this embodiment, the light-transmitting part 11a of the first light source 140 corresponding to the keycap 11 is within the opening 16 of the bracket 15, and most of the first circuit 139 will be located at positions outside the keycap 11, while a part of the first circuit 139 below the keycap 11 will be laid out in an area outside the openings 16 and 18 of the bracket 15 (i.e., the non-opening area of the bracket 15), and thus can be hidden under the bracket 15. Since the first circuit 139 of the composite light-emitting layer 130a is routed along the body of the bracket 15 and avoids the openings 16 and 18 corresponding to the light-transmitting area 138, it is not easily noticed by the user visually and will not affect the optical effect.

[0098] By Figure 2C and Figure 2DAs can be seen, the first light source 140 may include a plurality of light-emitting diodes 143, 144, 145. In one embodiment, the light-emitting diodes 143, 144, 145 emit lights of different wavelengths, such as red, green, and blue light-emitting diodes, but are not limited thereto. The light-emitting diodes 143, 144, 145 are respectively connected to three separate wires (collectively referred to as the first circuit 139), so that the light-emitting states of the light-emitting diodes 143, 144, 145 can be individually controlled, and there are light-emitting combinations of single-color emission or mixed light emission. That is, a plurality of light-emitting diodes of different colors (collectively referred to as the first light source 140) are arranged under a single key, and the keycap 11 can present a diverse backlight effect.

[0099] Figure 3 is a partial cross-sectional schematic diagram of a backlight module according to another embodiment of the present invention. Please refer to Figure 3 , Figure 3 the backlight module 100b of Figure 2B The main difference between the backlight module 100a of

[0100] Figure 4A is an exploded schematic diagram of a backlight module according to another embodiment of the present invention. Figure 4B is Figure 4A a partial cross-sectional schematic diagram of the backlight module of Figure 4A and Figure 4B, in this embodiment, the first light source 140 of the backlight module 100c and the light guide plate 120 are on the same side of the light-transmissive substrate (i.e., the film 135). The light guide plate 120 has holes 122. The first light source 140 is disposed at a position on the surface of the light-shielding plate 134 facing the reflector 110 corresponding to the holes 122. The first light source 140 extends into the holes 122 or is disposed at the periphery of the holes 122. The light emitted by the first light source 140 is adapted to enter the light guide plate 120, be reflected by the reflector 110 and emitted from the light-transmissive area 138. In addition, the position where the first light source 140 is disposed on the light-shielding plate 134 is, for example, corresponding to the light-shielding pattern 133. The light of the first light source 140 can be reflected back into the light guide plate 120 by the reflective coating 136 and continue to be transmitted and evenly distributed along the entire light guide plate 120, and the leakage of light from the light-shielding coating 137 can be prevented.

[0101] In this embodiment, since the first circuit 139 and the first light source 140 disposed on the light-shielding plate 134 can achieve the side-emitting light source to emit light toward the light guide plate 120, and achieve the optical path of the second light source 160 as shown in Figure 2A and Figure 2B , the backlight module 100 of this embodiment can omit Figure 2A and Figure 2B the flexible circuit board 150 and the second light source 160, and can thin the thickness of the backlight module 100c. That is to say, the first light source 140 of this embodiment is not used to achieve the independent light emission of a single key, but to make the light emitted by the first light source 140 enter the light guide plate 120 for total reflection and then emit upward, providing a backlight effect with uniform overall brightness to replace the side-emitting light source.

[0102] Figure 4C is a partial cross-sectional schematic view of a backlight module according to another embodiment of the present invention. Please refer to Figure 4C , in this embodiment, the composite light-emitting layer 130c1 of the backlight module 100c1 is disposed below the light guide plate 120 and can serve as the reflector of the backlight module 100c1. The bracket based on the key structure is disposed above the backlight module 100c1, and the light guide plate 120 is disposed between the bracket and the composite light-emitting layer 130c1. In addition, a light-shielding plate 134 can be further disposed above the light guide plate 120. The light emitted by the composite light-emitting layer 130c1 under the light guide plate 120 is adapted to enter the light guide plate 120 for total reflection, and is emitted toward the key structure from the part of the light guide plate 120 not shielded by the light-shielding coating 137.

[0103] The above-mentioned composite light-emitting layer 130c1 includes a light-transmissive substrate 111, a first circuit 112, a first light source 170, and a first protective layer 172 disposed on the light-transmissive substrate 111. The first light source 170 is electrically connected to the first circuit 112. The first circuit 112, the first light source 170, and the light guide plate 120 are located on the same side (such as the upper surface) of the light-transmissive substrate 111. The light guide plate 120 has holes 123, and the first light source 170 on the light-transmissive substrate 111 is disposed corresponding to the holes 123. In an embodiment, the first light source 170 extends into the holes 123 or is located at the periphery of the holes 123. The first protective layer 172 covers the first circuit 112 to prevent damage to the circuit pattern for supplying power to the first light source 170. The first protective layer 172 can be a reflective coating (such as white paint) or a reflective plastic film, which can reflect light back into the light guide plate 120 and avoid the material of the first circuit 112 affecting the optical effect of the backlight module 100c1.

[0104] As described above, the first light source 170 is exposed outside the first protective layer 172 to prevent the first protective layer 172 from covering the first light source 170 and obstructing the light from entering the light guide plate 120. In addition, a light-shielding coating 117 is provided on the lower surface of the light-transmissive substrate 111 as a light-shielding pattern of the composite light-emitting layer 130c1. The light-shielding coating 117 and the first light source 170 are located on opposite sides of the light-transmissive substrate 111, and the light-shielding coating 117 is, for example, fully coated on the lower surface of the light-transmissive substrate 111 to prevent the light of the first light source 170 from escaping from the bottom of the composite light-emitting layer 130c1. That is to say, the top of the composite light-emitting layer 130c1 has a reflective first protective layer 172 and the bottom has a light-shielding coating 117 (i.e., a light-shielding pattern), so it can also serve as a reflector of the backlight module 100c1 while providing a light-emitting function.

[0105] The above embodiment is described by taking the composite light-emitting layer as an example to separately provide the function of an upper light-emitting light source or a side light-emitting light source; however, in other embodiments of the present invention, these two forms of light sources can be integrated into the same composite light-emitting layer. Figures 5 to 7 It is a partial cross-sectional schematic diagram of various backlight modules according to other embodiments of the present invention. Similarly, in order to clearly show the composition of the backlight module of the embodiment of the present invention, the following diagrams will omit the key structure, but it should be understood that the following backlight module is disposed below the key structure to provide key backlight, and the components that are the same or similar to the foregoing embodiments will be denoted by the same symbols.

[0106] Please refer to Figure 5, in the backlight module 100d of the present embodiment, the composite light-emitting layer 130d includes a film 135, a first circuit 139, a first light source 140, and a first protective layer 142 disposed on the film 135. The composite light-emitting layer 130d further includes a second light source 180, a second circuit 182, and a second protective layer 184. In the present embodiment, the film 135 is a light-transmissive substrate, and the first circuit 139, the first light source 140, the second circuit 182, and the second light source 180 are disposed on the same side surface of the light-transmissive substrate (film 135), and the first light source 140 and the second light source 180 are electrically connected to the first circuit 139 and the second circuit 182, respectively. Similar to the first protective layer 142 covering the first circuit 139, the second protective layer 184 covers the second circuit 182, so that at least a part of the second circuit 185 is located between the second protective layer 184 and the light-transmissive substrate (film 135) to prevent the circuit pattern from being damaged. The first light source 140 and the second light source 180 are located on the same side of the light-transmissive substrate (film 135), and a manufacturing process step can be performed on the film 135 to simultaneously form the first circuit 139 and the second circuit 182, and simultaneously dispose the first protective layer 142 and the second protective layer 184 on the first circuit 139 and the second circuit 182. Therefore, the types of the first circuit 139 and the second circuit 182 can be the same, and the first protective layer 142 and the second protective layer 184 can be the same continuous film layer.

[0107] The first light source 140 and the second light source 180 are disposed on the surface of the film 135 facing away from the light guide plate 120 (i.e., the upper surface). The reflective coating 136 and the light-shielding coating 137 of the light-shielding pattern are, for example, disposed above the first light source 140. The light emitted by the first light source 140 is reflected upward by the reflective coating 136 and then enters the light guide plate 120 downward, and then is reflected by the reflector 110 and exits upward from the portion not shielded by the light-shielding coating 137, so as to achieve the effect of uniform light emission. Since the upper part of the second light source 180 is not shielded, the light emitted therefrom directly goes in the direction away from the light guide plate 120 and exits upward, so as to achieve the effect of single-button light emission. The first light source 140 is adapted to emit light toward the light guide plate 120 to provide a uniformly bright overall backlight, and is used to replace the side-emitting light source; while the second light source 180 is used as an upper-emitting light source to provide independent light emission for special buttons. The upper-emitting second light source 180 may include a plurality of light-emitting diodes (not shown) that emit different wavelengths, and has a combination of light emissions of multiple colors. In addition, the film 135 may further have a light-shielding pattern below the corresponding second light source 180, which can further prevent the light of the second light source 180 from entering the light guide plate 120 downward and affecting the light mixing. In this way, the backlight module 100d disposed under the key structure can simultaneously provide uniform backlight for the entire keyboard and highly directional light emission for specific keys through the composite light-emitting layer 130d, presenting a diverse backlight effect.

[0108] Please refer toFigure 6 , Figure 6 The main difference between the backlight module 100e of Figure 6 and the backlight module 100d of Figure 5 is that, in this embodiment, the light guide plate 120e further has a plurality of microstructures 124. Specifically, the light guide plate 120e has a plurality of separated microstructures 124 at a position corresponding to the first light source 140 on the surface away from the first light source 140, for changing the optical path and making the light dispersion uniform, and locally correcting the optical effect by using the distribution of the microstructures 124. In one embodiment, the microstructures 124 of the light guide plate 120e are concave-convex microstructures, which are, for example, in the profile of having concave prisms, annular V-grooves, dots or a combination of the above, and can increase light refraction or scattering on the lower surface of the light guide plate 120e to change the light transmission direction and make the light dispersion uniform. The microstructures 124 can also be only arranged at the position corresponding to the first light source 140 on the lower surface of the light guide plate 120e, or can be arranged on the entire lower surface of the light guide plate 120e. In addition, the microstructures 124 of the light guide plate 120e can also be arranged corresponding to the light-transmitting character area of the keycap. Therefore, when the backlight module 100e is arranged under the key structure, the microstructures 124 are, for example, distributed under the opening of the bracket to adjust the light emission angle so that the light can irradiate upward from the opening of the bracket to the back of the keycap.

[0109] Please refer to Figure 7 , Figure 7 The main difference between the backlight module 100f of Figure 7 and the backlight module 100d of Figure 5 is that, in this embodiment, the first light source 141 and the second light source 181 of the backlight module 100f are arranged on the surface of the light-shielding plate 134 facing the reflector 110. That is, the first light source 141, the second light source 181 and the light guide plate 120 are on the same side of the light-shielding plate 134. The first light source 141 and the second light source 181 are arranged on the lower surface of the thin film 135, and the light guide plate 120 has holes 122. The first light source 141 and the second light source 181 are arranged corresponding to the holes 122, for example, extending into the holes 122 or located at the periphery of the holes 122, so that the upper surface of the thin film 135 of the light-shielding plate 134 is flat. The reflective coating 136 and the light-shielding coating 137 are arranged above the first light source 141. Similarly, the light emitted by the first light source 141 is reflected upward by the reflective coating 136 and then enters the light guide plate 120 downward, and then is reflected by the reflector 110 and shoots upward from the part not shielded by the light-shielding coating 137, so as to achieve the effect of uniform light emission. The second light source 181 is not shielded, and the light emitted by it directly shoots upward in the direction away from the reflector 110, so as to achieve the effect of independent lighting of specific keys.

[0110] ​​​​In summary, the illuminated keyboard and backlight module of the present invention have a composite light-emitting layer disposed under the bracket of the key structure. The first light source and the first circuit are integrated in the composite light-emitting layer with a light-shielding pattern, so that the backlight module has a smaller thickness. The optical path of the first light source can be selectively designed to emit light in a direction away from the light guide plate and directly pass through the key structure to provide a highly directional optical effect for individual keys; or / and, the optical path of the first light source can be selectively designed to enter the light guide plate for transmission and then be emitted from the light-transmitting area, so as to provide overall backlight with uniform brightness.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A backlight module, adapted to be disposed under a bracket of a key structure, characterized in that, The backlight module includes: A light guide plate; A composite light-emitting layer disposed on one side of the light guide plate. The composite light-emitting layer includes a first light source, a second light source, a first circuit, and a first protective layer, and has a light-shielding pattern. The first light source is electrically connected to the first circuit, and the first protective layer covers part of the first circuit. Wherein the first light source is disposed corresponding to the opening of the bracket, the first light source is disposed directly below the keycap of the key structure, the first light source has a light-emitting surface facing the keycap, the light-shielding pattern is located on the opposite side of the light-emitting surface and at least partially overlaps the first light source in a direction perpendicular to the light guide plate, and the light-shielding pattern is also located above the second light source and at least partially overlaps the second light source in the direction perpendicular to the light guide plate.

2. The backlight module according to claim 1, wherein The composite light-emitting layer includes a light-transmissive substrate, the first circuit disposed on the light-transmissive substrate, and the light-shielding pattern. The first light source is disposed on the light-transmissive substrate, and the light-shielding pattern is located between the light guide plate and the light-transmissive substrate or between the key structure and the light-transmissive substrate.

3. The backlight module according to claim 1, wherein Further includes: A reflector disposed under the light guide plate; A circuit board disposed under the reflector; and A second light source disposed and electrically connected to the circuit board, passing through the reflector and extending beside the light guide plate. Wherein the first circuit is electrically connected to the circuit board.

4. The backlight module according to claim 1, wherein The first protective layer of the composite light-emitting layer has a reflective or reflective property, and the light guide plate has a plurality of microstructures disposed on the surface facing the first protective layer.

5. The backlight module according to claim 4, wherein Further includes a light-shielding plate disposed on the light guide plate, wherein the first light source corresponds to the light-shielding pattern of the light-shielding plate.

6. The backlight module according to claim 4, characterized in that Further includes: A film disposed on the light guide plate; A light-shielding coating disposed on one side of the film; And A reflective coating disposed between the film and the light-shielding coating. Wherein the first protective layer is located at the top of the composite light-emitting layer, the light-shielding pattern is located at the bottom of the composite light-emitting layer, and the first light source is disposed on the surface of the composite light-emitting layer facing the reflective coating or the light-shielding coating.

7. The backlight module according to claim 1, wherein Further includes a light-shielding plate disposed on the light guide plate and the first circuit disposed on the light-shielding plate, and the first light source is disposed on the surface of the light-shielding plate facing away from the light guide plate.

8. The backlight module according to claim 1, wherein The first circuit is located at a position corresponding to the light-shielding pattern.

9. The backlight module according to claim 1, wherein The composite light-emitting layer further includes a light-transmissive substrate, the first circuit and the first light source are disposed on the light-transmissive substrate, the first light source and the light guide plate are on the same side of the light-transmissive substrate, and at least part of the first circuit is located between the first protective layer and the light-transmissive substrate.

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