TWI851116B - Lighting keyboard, backlight module and lighting board - Google Patents

Abstract

A backlight module is configured to illuminate at least one key cap. The backlight module includes a light emitting unit, a light guide plate and a lighting board. The light guide plate has a light guide plate hole for accommodating the light emitting unit. The lighting board has a pair of pads connected to the light emitting unit respectively. The lighting board includes a first reflective layer surrounding the light emitting unit and at least partially covering the pair of pads. Each of the pair of pads has a plurality of branches and at least one hollow area. The at least one hollow area overlaps with at least one part of the light emitting unit.

Description

Illuminated keyboard, backlight module and light board

The present invention relates to a luminous keyboard, a backlight module and a light board, and in particular to a luminous keyboard, a backlight module and a light board that can improve the consistency of overall luminescence.

With the development of technology, keyboard designs are becoming more and more diverse. When users choose a keyboard, in addition to the basic input function, the keyboard's visual effect is also valued by users. Currently, luminous keyboards have been launched on the market. In addition to being visually attractive to users, they can also be used at night or in places with insufficient lighting. It is known that luminous keyboards use low-brightness LEDs to illuminate each square key, so the following problems will arise: 1) The main symbol above the LED is too bright, while the corner symbol of the keycap is too dark; 2) The brightness of the light around the keycap is inconsistent; and 3) The overall lighting of a single key and multiple keys is inconsistent.

One of the purposes of the present invention is to provide a luminous keyboard, backlight module and light panel that can improve the consistency of overall luminescence to solve the above problems.

According to an embodiment, the present invention provides a backlight module for illuminating at least one keycap, the backlight module comprising a light-emitting unit, a light guide plate and a lamp plate. The light guide plate has a light guide plate hole to accommodate the light-emitting unit. The lamp plate has a pair of welding pads respectively connected to the light-emitting unit, and the lamp plate includes a first reflection layer surrounding the light-emitting unit and at least partially covering the welding pads. Each of the welding pads has a plurality of branch lines and at least one hollow area, and the at least one hollow area overlaps at least a portion of the light-emitting unit.

According to another embodiment, an inner ring of the first reflective layer at least partially covers the branch line and the hollow areas, and the inner ring partially reflects and diffuses the light of the light-emitting unit. According to another embodiment, the light board further includes a pair of microstructure areas spaced apart from each other and located on the first reflective layer, the pair of microstructure areas jointly surround the pair of welding pads, and the pair of microstructure areas reflect and diffuse the light of the light-emitting unit transmitted through the light guide plate. According to another embodiment, the light board further includes a pair of microstructure areas spaced apart from each other and located on the first reflective layer, and the pair of microstructure areas do not overlap the two wires. According to another embodiment, at least one of the plurality of branch lines of the pair of solder pads is not completely covered by the first reflective layer, and an exposed portion of the branch line of each of the solder pads reflects and diffuses the light of the light-emitting unit. According to another embodiment, the light guide plate has a light guide plate hole for accommodating the light-emitting unit, and at least a portion of the first reflective layer is located in the light guide plate hole. According to another embodiment, the backlight module includes a shading plate, and the shading plate includes an internal reflective portion overlapping the first reflective layer. According to another embodiment, the plurality of branch lines of the pair of solder pads constitute a pair of parallel flat edges, and the short side of the light-emitting unit is smaller than the width of the pair of flat edges. According to another embodiment, at least one of the plurality of branch lines of the pair of solder pads surrounds at least a portion of the light guide plate hole. According to another embodiment, the first reflective layer has a reflective layer hole, and the at least one hollow area of the welding pad surrounds and/or overlaps the reflective layer hole. According to another embodiment, the first reflective layer has a reflective layer hole, and the reflective layer hole is located between the light-emitting unit and the light guide plate hole. According to another embodiment, the first reflective layer has a reflective layer hole, and a portion of the first reflective layer overlapping the welding pad is located between the reflective layer hole and the light guide plate hole. According to another embodiment, the light-emitting unit includes three chips to provide three-color light, and the three chips are arranged in succession with their short sides facing short sides. According to another embodiment, the light panel has two wires electrically connected to the welding pads, and the first reflective layer covers the two wires. According to another embodiment, the light board further comprises a pair of spaced microstructure regions located on the first reflective layer, and the two wires are located between the pair of microstructure regions. According to another embodiment, the light board has two sub-wires electrically connected to the welding plate, and the light board also has two main wires electrically connected to the two sub-wires. According to another embodiment, the light board further comprises a pair of spaced external microstructure regions located on the first reflective layer, and the pair of external microstructure regions are located outside the two main wires.

According to another embodiment, the present invention provides a backlight module for illuminating at least one keycap, the backlight module comprising a light guide plate, a light unit and a lamp board, wherein the backlight module defines a plurality of light-averaging regions to average the light of the light unit, the plurality of light-averaging regions comprising a first region and a second region. The first region surrounds the light unit, the first region comprises an inner ring portion of a first reflective layer and a pair of welding pads, the pair of welding pads are located on the lamp board for connecting the light unit, the inner ring portion of the first reflective layer at least partially covers the pair of welding pads, and the inner ring portion of the first reflective layer reflects and diffuses the light of the light unit. The second area surrounds the first area, and the second area includes a pair of microstructure areas spaced from each other and located on the first reflective layer. The pair of microstructure areas surround the pair of pads together, and the pair of microstructure areas reflect and diffuse the light transmitted by the light-emitting unit through the light guide plate.

According to another embodiment, the present invention provides a luminous keyboard, including a plurality of keys each having a key cap. The luminous keyboard also includes a backlight module of each of the aforementioned embodiments, and the backlight module is located below the plurality of keys.

According to another embodiment, the invention provides a light panel, comprising two non-intersecting wires, a plurality of microstructure regions, a light-emitting unit and a pair of pads. Two of the plurality of microstructure regions are separated from each other, and the two microstructure regions do not overlap with the two non-intersecting wires. The light-emitting unit is located between the two microstructure regions. The pair of pads electrically connects the two non-intersecting wires and the light-emitting unit, and the pair of pads has at least one branch line to form a pair of parallel flat edges, and the pair of pads also has at least one hollow area, and the light-emitting unit overlaps at least a portion of the at least one hollow area of the pair of pads.

In summary, the present invention forms a protruding structure between two non-intersecting conductors or multiple microstructure regions, and the position of the protruding structure corresponds to the position of the light-emitting unit, thereby increasing the amount of light emitted by the light-emitting unit entering the light guide plate, and using the specially configured microstructure area on the lamp board to recycle light or assist light emission, thereby improving the consistency of the overall lighting.

In addition, each embodiment of the present invention solves the connection stability problem of the light-emitting unit and the problem of excessive light concentration in the vicinity of the light-emitting unit. In addition to using a solder pad with a hollow area to ensure that the light-emitting unit can still be smoothly connected when the component is offset, the solder pad and its hollow area are further used to form a light homogenization design in the first area with the first reflective layer; in addition, with the internal microstructure area of the light board in the second area, the glue layer and the glue-free area in the third area, the present invention provides different light homogenization solutions for different blocks along the light path from the light-emitting unit to the outside, and can achieve a high degree of homogenization in both a single key and the entire keyboard.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the attached drawings.

LKB: Luminous keyboard

BLM: Backlight module

KS, KS1, KS2, KS3: Buttons

KCC: Keycaps

KC0: Internal light-transmitting area

KC1: External light-transmitting area

KC2: opaque area

SSR: Support device

MEM: Circuit board

SUP: bottom plate

LCB: Light Board

LGP: Light Guide Plate

SS: Shade

LT,HT,STa,STb: Conductor

LED: light emitting unit

RL1: First reflection layer

RL2: Second reflection layer

RL0: internal reflection part

RLH: Reflection layer hole

ML:Mask layer

ML0: Internal mask part

MLH: Mask layer holes

PL: Protective layer

MS,LMS: microstructure region

IMS: Internal Microstructure Region

OMS: External Microstructure Region

cMS: nuclear microstructure region

L0: light guide hole

Sc: Inner hole

Sr0: Ring rib

Sr1: Bridge rib

Sf: Support frame

SUPH: Peripheral hole

BP,SP: protruding structure

IP: Groove

Gx, Gy: Gap

BH: Plate hole

MP: Masking Department

HA: Porous gel

HC: Porosity

Ah/Ah1/Ah2: glue layer

AP:Colloid gap

Br: branch line

CL: Conductive layer

CA: glue-free area

Dt: conductor direction

Dn: Normal direction (conductor)

FP: solder pad

FG: Pad gap

Ha,Hb: hollow area

IE: Intersection point

RL1i: Inner ring part

RLH1: Reflection layer hole

Figure 1 is a schematic diagram of a luminous keyboard according to an embodiment of the present invention.

Figure 2 is a partial top view of the illuminated keyboard in Figure 1.

Figure 3 is a partial exploded view of the illuminated keyboard in Figure 1.

Figure 4 is a partial cross-sectional view of the luminous keyboard in Figure 1.

Figure 5 is a partial top view of a luminous keyboard according to another embodiment of the present invention.

Figure 6 is a partial cross-sectional view of the luminous keyboard in Figure 5.

Figure 7 is a partial cross-sectional view of a luminous keyboard according to another embodiment of the present invention.

Figure 8 is a partial cross-sectional view of a luminous keyboard according to another embodiment of the present invention.

Figure 9 is a partial cross-sectional view of a luminous keyboard according to another embodiment of the present invention.

Figure 10 is another partial top view of the luminous keyboard in Figure 1.

Figure 11 is another partial top view of the luminous keyboard in Figure 1.

Figure 12A is a top view schematic diagram of the end-to-end connection between the (sub) wires of the light board, the pads and the light-emitting unit in another embodiment of the present invention.

Figure 12B is a partially enlarged schematic diagram of the embodiment of Figure 12A.

Figure 12C is a top view schematic diagram of the side connection of the embodiment of Figure 12A.

Figures 13A to 13F are respectively top views of the connection structure between the (sub) conductors of the light board and the two pads and the light-emitting unit in different embodiments of the present invention.

Figure 14A is a partial top view schematic diagram of the optical structure of the backlight module in the area around the light-emitting unit in another embodiment of the present invention.

Figure 14B is a partial cross-sectional schematic diagram of the backlight module of the embodiment of Figure 14A.

Figure 14C is a partial top view schematic diagram of the optical structure of the backlight module in the area around the light-emitting unit in another embodiment of the present invention.

Figure 14D is a partial top view schematic diagram of the optical structure of the backlight module of the derivative embodiment of Figure 14A of the present invention.

The use of low-power light-emitting units such as Mini LED or Micro LED can reduce power consumption, reduce the total heat generated by the backlight module, and reduce the overall thickness of the backlight module, which helps to further thin the overall illuminated keyboard. However, the highly limited luminous range of Mini LED or Micro LED brings great challenges to the luminous uniformity of the single key and the entire keyboard. The embodiment of the present invention first focuses on how to achieve a large proportion of the light from the light-emitting unit entering the light guide plate for horizontal transmission, and how to effectively recycle the light that passes through the light guide plate during the horizontal transmission process into the light guide plate for reuse.

Please refer to Figure 1, which is a schematic diagram of a luminous keyboard LKB according to an embodiment of the present invention.

As shown in FIG. 1 , the luminous keyboard LKB includes a backlight module BLM and a plurality of keys KS. A base plate SUP is disposed on the backlight module BLM, and the plurality of keys KS are disposed on the base plate SUP. Generally speaking, the plurality of keys KS may include square keys and multiple keys (e.g., blank keys). It should be noted that the number, size, and arrangement of the keys KS may be determined according to actual applications and are not limited to the embodiments shown in the figure.

The backlight module BLM includes a lamp board LCB, a light guide plate LGP and a light shielding plate SS. The light guide plate LGP is disposed on the lamp board LCB, and the light shielding plate SS is disposed on the light guide plate LGP. Each key KS on the light-emitting keyboard LKB corresponds to at least one light-emitting unit (e.g., light-emitting diode) on the lamp board LCB of the backlight module BLM.

Please refer to Figures 2 to 4. Figure 2 is a partial top view of the luminous keyboard LKB in Figure 1, Figure 3 is a partial exploded view of the luminous keyboard LKB in Figure 1, and Figure 4 is a partial cross-sectional view of the luminous keyboard LKB in Figure 1.

As shown in FIGS. 2 to 4, the light board LCB includes two non-intersecting wires LT and HT, another two non-intersecting wires STa and STb, a light-emitting unit LED, a first reflective layer RL1, and a plurality of microstructure regions MS. The light board LCB can be a lighting circuit board. The light-emitting unit LED is connected between the two non-intersecting wires STa and STb, and the light-emitting unit LED is connected between the two non-intersecting wires LT and HT via the two non-intersecting wires STa and STb. In this embodiment, the wires LT and HT are the main driving circuits of the light-emitting unit LED, and the wires STa and STb are the sub-driving circuits of the light-emitting unit LED, wherein the wire LT can be a low potential wire, and the wire HT can be a high potential wire. The light-emitting unit LED can be a white light-emitting diode or a combination of red, green and blue light-emitting diodes, depending on the actual application. Generally speaking, the wires LT and HT are main wires with larger cross-sectional areas, which can cross multiple keys KS. The wires LT and HT do not intersect at least within the range of a single key KS, and may also not intersect within adjacent multiple keys KS and a larger continuous area covering the key gaps. The pair of wires STa and STb set within each single key KS are sub-wires with smaller cross-sectional areas. Although they may be located on the same straight line, the ends of the wires STa and STb are respectively connected to the two electrodes of the light-emitting unit LED, so the wires STa and STb do not overlap.

The first reflective layer RL1 is arranged on two non-intersecting conductors LT, HT and another two non-intersecting conductors STa, STb. A plurality of microstructure regions MS are formed on the first reflective layer RL1. In the present embodiment, the microstructure region MS may be a concave-convex structure formed on the first reflective layer RL1. For example, the light board LCB may be formed of a flexible circuit board, and a copper mesh is often used to enhance the supporting strength of the circuit board. The first reflective layer RL1 may be formed by spraying a reflective paint or coating a reflective film on the surface of the flexible circuit board (including the copper mesh surface). The grid structure of the copper mesh will form regular concave points (grid points) and convex areas (grid lines) on the first reflective layer RL1. These concave points and convex areas have the function of reflection points, which can reflect light back to the light guide plate LGP; in fact, the copper wire area (wires LT, HT, STa, STb) can also become a convex linear reflection area. In principle, the copper mesh does not overlap with the wires LT and HT on the flexible circuit board, nor is it electrically connected to the wires STa and STb. However, in application, the copper mesh has a radio frequency interference shielding effect, so the copper mesh may be connected to the ground of the driving line. However, in practice, not any reflection layer covering the copper mesh and the line can produce a concave and convex reflection structure. If the first reflective layer RL1 is an independent thin film element, the thickness of the first reflective layer RL1 must be thin enough, for example, lower than the thickness of the copper foil substrate (including the adjacent flat copper mesh and copper wire areas), and the first reflective layer RL1 needs to have a high degree of plasticity to form a concave-convex microstructure in the copper mesh and copper wire areas when covering the copper foil substrate. If the first reflective layer RL1 is formed by ink coating, for example, the coating thickness, ink concentration, coating area control, etc. must be strictly controlled, otherwise the original hollow areas of the copper foil substrate are easily filled with ink flow, reducing the depth of the reflective microstructure and the reflective diffusion effect.

In addition, even if the circuit of the light board LCB is not a copper foil substrate, there is no thick copper circuit, and there is no copper mesh to enhance the structural strength of the light board LCB, a microstructure with a diffusion effect can still be formed on the first reflective layer RL1. For example, printing micro-dot ink on the first reflective layer RL1 forms concave/convex areas as microstructure areas MS; or, using ink with larger reflective particles, when spraying or printing the first reflective layer RL1, concave/convex areas are formed as microstructure areas MS; or, if the first reflective layer RL1 is a layer of reflective film, the reflective film surface can be selected as long as it has reflective particles with medium to low flatness and has an uneven reflective surface, which can be used as the microstructure area MS.

In this embodiment, within the scope of a single key KS, the plurality of microstructure regions MS include two internal microstructure regions IMS and two external microstructure regions OMS, wherein the two internal microstructure regions IMS are located between the two non-intersecting wires LT and HT, and the two external microstructure regions OMS are located outside the two non-intersecting wires LT and HT. The pattern of the two internal microstructure regions IMS may be different from the pattern of the two external microstructure regions OMS, but is not limited thereto. The light-emitting unit LED is located between the plurality of microstructure regions MS, that is, the light-emitting unit LED is located between the two internal microstructure regions IMS and also between the two external microstructure regions OMS.

In this embodiment, the wires STa and STb divide two internal microstructure regions IMS, so the wires STa and STb are also located between the two internal microstructure regions IMS; similarly, the wires LT and HT divide an external microstructure region OMS and two internal microstructure regions IMS, respectively, so it can also be said that the wires LT and HT are located between an external microstructure region OMS and two internal microstructure regions IMS, respectively. In some embodiments, the aforementioned plurality of microstructure regions MS, whether the external microstructure region OMS or the internal microstructure region IMS, do not overlap the wires LT and HT, nor do they overlap the wires STa and STb; for example, this is the case when the circuit of the lamp panel LCB is copper wire matched with a copper mesh. If the microstructure area MS on the first reflective layer RL1 is only surface treated instead of being formed from the copper mesh or other substrate below, multiple microstructure areas MS/OMS/IMS may overlap the wires LT, HT, or overlap the wires STa, STb. The light guide plate LGP has a light guide hole L0, and the light-emitting unit LED is located in the light guide hole L0. The top and/or bottom surface of the light guide plate LGP near the light guide hole L0 may have an adhesive surrounding the light guide hole L0 to respectively bond the shading plate SS and/or the lamp board LCB. In addition, the light guide plate LGP also has multiple microstructure areas LMS corresponding to the positions of the inner holes Sc and the peripheral holes SUPH of the bottom plate SUP, so as to guide the light transmitted in the light guide plate LGP to emit light upward. Below the orthographic projection of the peripheral hole SUPH of the base plate SUP, the microstructure area LMS of the light guide plate LGP can at least partially overlap with the multiple microstructure areas MS of the first reflective layer RL1 of the lamp board LCB, and in particular can increase the light output effect through the inner hole Sc and the peripheral hole SUPH, and enhance the brightness of the corner symbols (external light-transmitting area KC1) of the key cap KCC. The internal microstructure area IMS on the first reflective layer RL1 of the lamp board LCB near the light-emitting unit LED can be used as an optical adjustment method. When the light output near the light-emitting unit LED is excessively weakened, for example, the internal masking part ML0 of the mask layer ML of the light-shielding sheet SS is too large, or the transmittance of one of the internal reflective parts RL0 of the second reflective layer RL2 is too low, the internal microstructure area IMS on the first reflective layer RL1 of the lamp board LCB near the light-emitting unit LED can enhance the light output effect of the light-transmitting area KC0 inside the inner hole Sc or the key cap KCC.

A better way to optimize the configuration of the aforementioned multiple microstructure areas MS/OMS/IMS is to set the wires STa, STb, LT, and HT to overlap with any rib area or frame area (such as annular rib Sr0, bridge rib Sr1, support frame Sf) of the bottom plate SUP as much as possible. In this way, the aforementioned multiple microstructure areas MS/OMS/IMS will be able to correspond to the microstructure area LMS of the light guide plate LGP, the peripheral hole SUPH or the inner hole Sc of the bottom plate SUP, and the inner light-transmitting area KC0 and the outer light-transmitting area KC1 of the key cap KCC. In addition, multiple microstructure areas MS/OMS/IMS may overlap the annular rib Sr0, bridge rib Sr1 or support frame Sf of the bottom plate SUP. Although these positions cannot emit light, the microstructure area MS/OMS/IMS can help guide the light that escapes from the light guide plate LGP into the light guide plate LGP for recycling, which is helpful for the subsequent light emission effect of another key KS that is further outside or even adjacent. Of course, the aforementioned microstructure area MS/OMS/IMS can also overlap with the second reflective layer RL2 of the shading plate SS, including overlapping with the internal reflective part RL0 and the outer frame part of the second reflective layer RL2, which is helpful for recycling light to the light guide plate LGP.

The shading plate SS is disposed above the plurality of microstructure regions MS. The shading plate SS comprises a mask layer ML, a second reflective layer RL2 and a protective layer PL, wherein the mask layer ML, the second reflective layer RL2 and the protective layer PL can be stacked on each other in various ways. For example, any one of the mask layer ML, the second reflective layer RL2 and the protective layer PL can be stacked on the top, the middle or the bottom to form the shading plate SS. The mask layer ML is opaque. The second reflective layer RL2 can have both reflective and translucent properties, that is, the second reflective layer RL2 can reflect part of the light and allow part of the light to pass through. The mask layer ML can be black paint, and the second reflective layer RL2 can be white paint, but not limited thereto. In this embodiment, the mask layer ML has a mask layer hole MLH and an internal mask portion ML0 located in the mask layer hole MLH, and the second reflective layer RL2 has a reflective layer hole RLH and an internal reflective portion RL0 located in the reflective layer hole RLH. The mask layer hole MLH can be larger, equal to or smaller than the reflective layer hole RLH, and the internal mask portion ML0 can be larger, equal to or smaller than the internal reflective portion RL0, depending on the desired luminous effect. The internal mask portion ML0 and the internal reflective portion RL0 are located above the light-emitting unit LED. In this embodiment, the internal mask portion ML0 and/or the internal reflective portion RL0 above the light-emitting unit LED are at least partially projected between two non-intersecting conductors LT, HT or STa, STb.

Each key KS includes a portion of the bottom plate SUP. In the present embodiment, the bottom plate SUP has an inner hole Sc, an annular rib Sr0, a plurality of bridging ribs Sr1, and a support frame Sf, wherein the annular rib Sr0 surrounds the inner hole Sc, and the plurality of bridging ribs Sr1 connect the annular rib Sr0 and the support frame Sf. In addition, there are a plurality of peripheral holes SUPH between the bridging rib Sr1, the annular rib Sr0, and the support frame Sf. In the present embodiment, the two internal microstructure regions IMS at least partially overlap with the projections of the inner hole Sc, the annular rib Sr0, the plurality of bridging ribs Sr1, and/or the support frame Sf. In addition, the two external microstructure regions OMS at least partially overlap with the projections of the annular rib Sr0, the plurality of bridging ribs Sr1 and/or the support frame Sf.

The key KS includes a key cap KCC, a support device SSR, a circuit board MEM and a base plate SUP. The key cap KCC is arranged relative to the base plate SUP. The key cap KCC has an internal light-transmitting area KC0 and a plurality of external light-transmitting areas KC1, wherein the internal light-transmitting area KC0 and the external light-transmitting area KC1 are surrounded by a non-light-transmitting area KC2. The positions of the internal light-transmitting area KC0 and the external light-transmitting area KC1 correspond to the positions of the inner hole Sc and the peripheral hole SUPH of the base plate SUP, respectively, so that the light emitted by the light-emitting unit LED can be projected from the internal light-transmitting area KC0 and the external light-transmitting area KC1 of the key cap KCC through the light guide plate LGP, the shading plate SS, the inner hole Sc and the peripheral hole SUPH of the base plate SUP. The support device SSR is disposed between the key cap KCC and the base plate SUP. When the key cap KCC is pressed, the key cap KCC moves vertically toward the base plate SUP along with the support device SSR. In addition, a reset member (not shown in the figure) is disposed between the key cap KCC and the base plate SUP, such as a rubber dome, but not limited thereto. The circuit board MEM has a switch corresponding to the key KS, such as a membrane switch or other trigger switch.

From the top view, the light-emitting unit LED, the light-guiding hole L0, the internal reflection part RL0, the internal mask part ML0, the inner hole Sc, the inner light-transmitting area KC0 and the adhesive around the light-guiding hole L0 can be located between the two non-intersecting conductors LT, HT and/or STa, STb.

From the top view, the light-emitting unit LED, the light-guiding hole L0, the internal reflection part RL0, the internal mask part ML0, the inner hole Sc, the inner light-transmitting area KC0, and the adhesive around the light-guiding hole L0 can be located between the two internal microstructure areas IMS.

As shown in FIG. 4 , the backlight module BLM further includes a protruding structure BP, wherein the position of the protruding structure BP corresponds to the position of the light-emitting unit LED, and the protruding structure BP is located between two non-intersecting wires LT and HT. In addition, the protruding structure BP is also located between a plurality of microstructure regions MS, that is, the protruding structure BP is located between two internal microstructure regions IMS and between two external microstructure regions OMS. In this embodiment, the protruding structure BP is formed on the lamp board LCB, and the protruding structure BP forms a groove IP to accommodate the light-emitting unit LED, so that the upper surface of the light-emitting unit LED is flush with or lower than the upper surface of the light guide plate LGP and higher than the lower surface of the light guide plate LGP. Since the shading plate SS is arranged on the light guide plate LGP, the upper surface of the light-emitting unit LED will also be flush with or lower than the lower surface of the shading plate SS, so that the shading plate SS can remain flat and will not be pushed by the light-emitting unit LED and partially enter the inner hole Sc of the bottom plate SUP. In this way, the amount of light emitted by the light-emitting unit LED entering the light guide plate LGP can be increased, thereby improving the consistency of the overall lighting. Furthermore, the circuit board MEM can have a switch arranged corresponding to the inner hole Sc of the bottom plate SUP, so that the switch can partially enter the inner hole Sc of the bottom plate SUP without interfering with the SS shading plate and the light-emitting unit LED below it.

Please refer to Figure 5 and Figure 6. Figure 5 is a partial top view of the luminous keyboard LKB according to another embodiment of the present invention, and Figure 6 is a partial cross-sectional view of the luminous keyboard LKB in Figure 5.

As shown in Figures 5 and 6, the base plate SUP may not have the above-mentioned inner hole Sc. At this time, the shading plate SS remains flat and will not be pushed by the light-emitting unit LED. When the base plate SUP does not have the inner hole Sc, the key cap KCC may not have the internal light-transmitting area KC0. However, if the key cap KCC has an internal light-transmitting area KC0, the peripheral holes SUPH around the central area of the key cap KCC can be used to emit light, so that the light is projected from the internal light-transmitting area KC0 without the inner hole Sc. In this embodiment, the two non-intersecting wires HT and LT may overlap with the projection of at least one of the at least one external light-transmitting area KC1. As long as the two non-intersecting wires HT and LT meet at least one of the following three conditions, the wires HT and LT will not affect the luminescence of the external light-transmitting area KC1 of the key cap KCC. Condition 1: The projections of the two non-intersecting conductors HT, LT and the annular ribs Sr0, bridge ribs Sr1 and/or support frame Sf of the bottom plate SUP overlap. Condition 2: The projections of the two non-intersecting conductors HT, LT and the mask layer ML and/or the second reflective layer RL2 of the shading plate SS overlap. Condition 3: The projections of the two non-intersecting conductors HT, LT and the opaque area KC2 of the key cap KCC overlap.

Please refer to Figure 7, which is a partial cross-sectional view of the luminous keyboard LKB according to another embodiment of the present invention.

As shown in FIG. 7 , the protruding structure SP of the backlight module BLM can be formed on the shading plate SS, wherein the light-emitting unit LED is located below the protruding structure SP. The position of the protruding structure SP corresponds to the position of the light-emitting unit LED, and the protruding structure SP is located between two non-intersecting conductors LT and HT. In addition, the protruding structure SP is also located between a plurality of microstructure regions MS, that is, the protruding structure SP is located between two internal microstructure regions IMS, and is also located between two external microstructure regions OMS. In the present embodiment, the protruding structure SP may be lower than or slightly enter the inner hole Sc of the bottom plate SUP, and the upper surface of the light-emitting unit LED is flush with or lower than the upper surface of the light guide plate LGP or the lower surface of the shading plate SS. It should be noted that the protruding structure SP can be pressed back so that the top of the shading plate SS below the bottom plate SUP has a flat surface. In FIG. 7 , the effect of the protruding structure SP formed on the light shielding plate SS may come from the fact that the second reflective layer RL2 on the light shielding plate SS above the light emitting unit LED is formed with a curved surface or a slope due to the protruding structure SP; because the reflection angle provided by the straight second reflective layer RL2 is small, it is difficult to guide the upward irradiated light to enter directly from the light guide hole L0 hole wall of the light guide plate LGP.

Please refer to Figure 8, which is a partial cross-sectional view of the luminous keyboard LKB according to another embodiment of the present invention.

As shown in Figure 8, the upper surface of the light-emitting unit LED can be higher than the upper surface of the light guide plate LGP and lower than the lower surface of the light shielding plate SS, that is, the upper surface of the light-emitting unit LED can be located between the upper surface of the light guide plate LGP and the lower surface of the light shielding plate SS. If necessary, the light-emitting unit LED can also exceed the upper surface of the LGP. For example, the protrusion structure SP can bulge upward to allow the thickness of the light shielding plate SS itself and the thickness of the upper and lower adhesive layers of the light shielding plate SS to provide space for accommodating the light-emitting unit LED; at this time, the upper surface of the light-emitting unit LED will be located between the lower surface of the bottom plate SUP and the upper surface of the LGP. Thus, when the upper surface of the light-emitting unit LED is higher than the upper surface of the light guide plate LGP, the protrusion structure SP can provide space for accommodating the light-emitting unit LED to prevent the light-emitting unit LED from interfering with the light shielding plate SS.

Please refer to Figure 9, which is a partial cross-sectional view of the luminous keyboard LKB according to another embodiment of the present invention.

As shown in FIG. 9, the light-emitting keyboard LKB may not include the protruding structure BP shown in FIG. 4 or the protruding structure SP shown in FIG. 7. In this embodiment, the upper surface of the light-emitting unit LED is flush with or lower than the upper surface of the light guide plate LGP and higher than the lower surface of the light guide plate LGP. In this way, the amount of light emitted by the light-emitting unit LED entering the light guide plate LGP can be increased, thereby improving the consistency of the overall lighting.

Please refer to Figure 10, which is another partial top view of the luminous keyboard LKB in Figure 1.

As shown in FIG. 10 , a plurality of microstructure regions OMS, IMS at least partially overlap with the projection of the gaps Gx, Gy between any two adjacent keys KS1, KS2, KS3. Three adjacent keys KS1, KS2, KS3 may have three adjacent external microstructure regions OMS, wherein the three adjacent external microstructure regions OMS are combined together in the X and Y directions. Two external microstructure regions OMS outside two non-intersecting conductors of the light board LCB disposed under a key KS may have the same pattern, and may have the same size, the same shape, and the same distance (outside the conductors) in two identical regions. Within the projection range of a single key KS (e.g., a square key), two external microstructure regions OMS may have different patterns defined by the key KS. For two keys KS adjacent to each other in the Y direction, two adjacent external microstructure regions OMS may have different patterns defined by the two adjacent keys KS.

Please refer to Figure 11, which is another partial top view of the luminous keyboard LKB in Figure 1.

As shown in FIG. 11 , a plate hole BH may be provided on the light board LCB, wherein the plate hole BH is used for fixing or heat dissipation. A mask portion MP may be provided on the light board LCB, wherein the mask portion MP surrounds the plate hole BH and is used to shield and absorb light to prevent light from leaking from the plate hole BH. In practice, the mask portion MP may be a light-absorbing or opaque substrate of the light board LCB, that is, the first reflective layer RL1, the circuit layer, and the insulating layer (if necessary) above the substrate of the light board LCB are all provided with holes larger than the plate hole BH, so as to expose the mask portion MP surrounding the plate hole BH. Another practical approach is to coat the upper surface of the first reflective layer RL1 of the light board LCB with a mask portion MP surrounding the plate hole BH. In this case, the hole size of the first reflective layer RL1 is similar to the plate hole BH. The plate hole BH and the mask portion MP on the light board LCB can correspond to the plate hole and the mask portion on the light shielding plate SS (not shown in the figure). The porous glue HA on the light board LCB can be set on the mask portion MP and surround the plate hole BH. The hole HC does not overlap with the external microstructure area OMS or any microstructure. The hole HC without the first reflective layer RL1 can be defined between the first reflective layer RL1 and the plate hole BH. The hole HC without glue can be defined between the porous glue HA and the plate hole BH. The internal microstructure region IMS (between two non-intersecting wires HT, LT and/or between STa, STb) does not overlap with the plate hole BH, the porous gel HA and/or the pore HC. A plurality of adjacent keys KS1, KS2, KS3 in the X and/or Y direction may have adjacent external microstructure regions OMS that jointly surround the mask portion MP, the plate hole BH, the porous gel HA and/or the pore HC. The mask portion MP, the plate hole BH, the porous gel HA and/or the pore HC are located between the wires HT, LT corresponding to the key KS1 and the wires HT, LT corresponding to the keys KS2, KS3. Furthermore, the mask MP, plate hole BH, porous gel HA and/or pore HC may be located between the wire LT corresponding to the key KS1 and the wire HT corresponding to the keys KS2 and KS3. It should be noted that the mask MP, porous gel HA and pore HC are schematically shown at the same position in Figure 11. However, the definitions of the mask MP, porous gel HA and pore HC can be clearly understood based on the above description.

In summary, the present invention makes the multiple microstructure areas on the lamp panel non-overlapping with the two non-intersecting wires, so that the specially configured microstructure areas on the lamp panel can be used to recycle light or assist light emission, thereby improving the consistency of the overall light emission. In addition, although the technical solution of the present invention is based on solving the application problem of low-power light-emitting units, the present invention is also applicable to the application of medium and high-power light-emitting units in backlight modules.

Furthermore, since the low-power light-emitting unit is too small, when it is installed on the light board, the melting of the solder paste can easily cause the position of the light-emitting unit to shift, resulting in the failure of smooth electrical connection between the light-emitting unit and the light board. The following embodiments of the present invention will introduce several technical solutions through a special solder pad design

Please refer to Figures 12A to 12C. Figure 12A is a top view schematic diagram of the end-to-end connection between the (sub) wires of the lamp panel and the pads and the light-emitting unit of another embodiment of the present invention. Figure 12B is a partial enlarged schematic diagram of the embodiment of Figure 12A. Figure 12C is a top view schematic diagram of the side connection of the embodiment of Figure 12A.

In FIG. 12A and FIG. 12B, two (sub) conductors STa/STb (see the aforementioned embodiment and FIG. 3, FIG. 8, and FIG. 9) extend along the conductor direction Dt, and the two (sub) conductors STa/STb have a pad FP at their ends, and a pad gap FG is provided between the two pads FP. Each pad FP can be directly formed integrally with the circuit of the light board LCB (such as the conductor HT/LT/STa/STb) through printed conductive wires, or can be formed integrally with the circuit of the light board LCB through a copper foil substrate etching process; however, each pad FP can also be formed twice, or the material of the circuit of the light board LCB is different. The two pads FP have an intersection point IE as the end, and the distance between the two intersection points IE is also the shortest distance between the two pads FP. The gap FG between the two intersection points IE is smaller than the long side of the light-emitting unit LED, for example, the gap between the two intersection points IE is close to 0.5 times the long side of the light-emitting unit LED or shorter. The intersection point IE can actually be the end point of the two adjacent ends of the pads FP, or the geometric center point of the two adjacent ends of the pads FP. The two pads FP of the present invention each have at least two branch lines Br (branch) extending outward from the intersection point IE, thereby defining at least one hollow area Ha/Hb. In Figure 12A/12B, each pad FP has three branch lines Br, of which the middle branch line Br extends straight outward from the intersection point IE to connect to the (sub) conductor STa/STb, and the remaining two left and right branch lines Br extend outward from the intersection point IE in an L-shaped path and also connect to the (sub) conductor STa/STb. The three branch lines Br of each pad FP jointly define two hollow areas Ha/Hb, and the border of the two hollow areas Ha/Hb extends along the middle branch line Br.

The positive and negative electrodes of the light-emitting unit LED are electrically connected to the two pads FP through a conductive layer CL, and the connection position is located at the two intersection points IE or their vicinity. The conductive layer CL is implemented, for example, with solder paste or its substitute material. The thickness and area of the conductive layer CL will affect the degree of deviation of the light-emitting unit LED during component bonding. Therefore, the printing of the conductive layer CL must be concentrated as much as possible at the intersection point IE of the two pads FP and extend to a limited extent along the branch line Br. The connection direction of the positive and negative electrodes of the light-emitting unit LED, or the long side of the light-emitting unit LED, is parallel to the wire direction Dt. The (flat side) width of the two pads FP can be set to be at least 0.8-1.5 times the short side of the LED. If the light-emitting unit LED is offset along the normal direction Dn of the wire STa/STb or along the short side of the light-emitting unit LED, the positive and negative electrodes of the light-emitting unit LED still have a considerable chance of ensuring electrical connection to the two pads FP. If the light-emitting unit LED is offset along the wire direction of the wire STa/STb or along the long side of the light-emitting unit LED, the offset must exceed 0.5 times the long side length of the light-emitting unit LED, so that the light-emitting unit LED cannot be electrically connected to the two pads FP at the same time. Regardless of how the light-emitting unit LED is offset, the light-emitting unit LED and one of the hollow areas Ha or Hb of one of the pads FP overlap at least partially, for example, a corner or one side of the light-emitting unit LED overlaps at least one hollow area Ha or Hb. The overall size of the two pads FP (including the hollow area Ha or Hb, the branch line Br and the pad gap FG) can be set to be at least 1.2 times larger than the light-emitting unit LED; or, the two pads FP each have at least one branch line Br forming a pair of parallel flat edges, and the short side of the light-emitting unit LED is preferably smaller than the width of the pair of flat edges of the two pads FP. In this way, even in the case of maximum offset, the light-emitting unit LED (either side) does not exceed the outermost periphery of any pad FP. In an ideal situation with no component offset, all four corners of the light-emitting unit LED can overlap with the hollow area Ha or Hb respectively. However, under the premise of highly stable process parameters, the flat side of the pad FP may be less than or equal to the short side of the light-emitting unit LED; even so, at least the light-emitting unit LED (such as a side or corner) must be able to overlap the hollow area Ha/Hb to maintain the basic offset prevention mechanism.

The first significance of the hollow area Ha/Hb is to provide at least two branch lines Br for each solder pad FP to connect the positive/negative electrodes of the light-emitting unit LED. Secondly, the intersection point IE of the intersection of the branch lines Br (or the end of the junction of the two hollow areas Ha/Hb) can be used as the positioning point of the light-emitting unit LED in the automated process. Furthermore, the conductive layer CL tends to flow along the branch line Br when it is melted, and the existence of the hollow area Ha/Hb prevents the conductive layer CL from flowing toward the hollow area Ha/Hb when it is melted to a considerable extent. In addition, the width of each branch line Br can be only 0.5 times or less of the short side of the light-emitting unit LED, so as to limit the range/angle of the melting flow of the conductive layer CL so as not to diffuse, and further limit the angle/path of the deviation of the light-emitting unit LED. In this way, it can be ensured that the light-emitting unit LED will be offset along the branch line Br, thereby improving the yield of the light-emitting unit LED electrically connecting the two pads FP and the two wires STa/STb.

Please refer to Figures 12A to 12C at the same time. In Figures 12A and 12B, the wires STa/STb are end-to-end opposite to each other, and their two hollow areas Ha and two hollow areas Hb are arranged perpendicular to the wire direction Dt. Figure 12C is different. The wires STa/STb are partially overlapped in the perpendicular wire direction Dt and are edge-to-edge opposite to each other, so the positions of the two pads FP are rotated 90 degrees, and the two hollow areas Ha and two hollow areas Hb are arranged along the wire direction Dt. Regardless of end-to-end or edge-to-edge connection, the hollow areas Ha/Hb and branch lines Br of the pad FP can effectively improve the yield of the two pads FP and the two wires STa/STb of the light-emitting unit LED electrical connection.

Please refer to Figures 13A to 13F, and also to Figures 12A to 12C. Figures 13A to 13F are respectively top views of the connection structure of the (sub) conductors STa/STb of the lamp board LCB and the two pads FP and the light-emitting unit LED in different embodiments of the present invention.

In Figures 12A to 12C, three branch lines Br form a T-shape, and each branch line Br is at least partially parallel to the short side and the long side of the light-emitting unit LED, but the present invention is not limited thereto. In Figure 13A, each pad FP has only two branch lines Br extending obliquely outward from the intersection IE, and the two branch lines Br of each pad FP form a blunt angle, and finally define a hollow area Ha/Hb with the two conductive wires STa/STb. Although the light-emitting unit LED in FIG. 13A still at least partially overlaps the hollow area Ha and/or Hb, the distance between the two branch lines Br on the same side of different pads FP will become larger and larger when the light-emitting unit LED shifts left and right along the normal direction Dn, so the blunt angle between the two branch lines Br of each pad FP should not be too small, for example, between 150 degrees and 180 degrees, so as to avoid the light-emitting unit LED shifting beyond the width of the two electrodes. A similar but better implementation example is shown in FIG. 13B, which is also a triangular pad FP, and the two angular branch lines Br are formed with flat sides opposite to the flat sides formed by the branch lines Br of another pad FP, so that the problem of the distance between the two branch lines Br on the same side of different pads FP will not occur when the light-emitting unit LED shifts. In addition, the width of the wires STa/STb in FIG. 13B is narrower (e.g., copper wires formed by etching a copper foil substrate, while the width of the wires STa/STb in FIG. 13A is wider (e.g., printed from a metal paste with lower conductivity than the etched copper wire). Both have no direct effect on the electrical connection between the pad FP and the light-emitting unit LED.

In Figure 13C, both pads FP have three branch lines Br, and the configuration is similar to Figures 12A and 12B. The middle branch line Br extends straight outward from the intersection IE to connect to the (sub) wire STa/STb, and the remaining two branch lines Br extend outward from the intersection IE in a U-shaped path and also connect to the (sub) wire STa/STb. The width of the wire STa/STb in Figure 13C is narrower, compared to the width of the wire STa/STb in Figures 12A and 12B. However, as mentioned above, the width of the wire STa/STb has little effect on the electrical connection between the pad FP and the light-emitting unit LED.

In Figure 13D, both pads FP have three branch lines Br, and the configuration is similar to Figure 13C. In Figure 13D, the middle branch line Br extends straight outward from the intersection point IE to connect to the (sub) conductor STa/STb, and the remaining left and right branch lines Br extend outward from the intersection point IE in a U-shaped path and also connect to the (sub) conductor STa/STb. The difference is that the shape of the pad FP in Figure 13D is closer to a semicircle, that is, the left and right branch lines Br in Figure 13D both have arc-shaped guide angles, which corresponds to the more arcs of the light guide hole L0 in the aforementioned Figure 3 or the subsequent Figures 14A to 14D, so that it can better match and increase the amount of light entering the side of the light guide plate LGP. In Figure 13E, although each pad FP has a branch line Br extending outward from the intersection point IE to form a flat edge, only the central branch line Br is connected to the (sub) conductor STa/STb. The left and right branch lines Br extend outward from the intersection point IE in a straight line path in the normal direction Dn, and do not extend to the (sub) conductor STa/STb or connect to the conductor STa/STb. However, the central branch line Br still defines a hollow area Ha/Hb with the left and right branch lines Br, respectively, so that the light-emitting unit LED at least partially overlaps one of the hollow areas Ha/Hb.

The pads FP in FIG. 13F are similar to those in FIG. 13D, but the middle branch line Br is missing. Only the left and right branch lines Br extend outward from the intersection IE in a U-shaped path and connect to the (sub) conductors STa/STb. The two pads FP and their branch lines Br in FIG. 13F also form a pair of parallel flat edges. Each of the two pads FP has only one hollow area Ha/Hb, so that the light-emitting unit LED at least partially overlaps (two short sides) at least one of the hollow areas Ha/Hb. The two short sides of the light-emitting unit LED in FIG. 13F respectively cross the hollow areas Ha/Hb, which is also similar to the triangular pads FP in FIG. 13A and FIG. 13B, but the pads FP and the hollow areas Ha/Hb in FIG. 13F are larger than those in FIG. 13A and FIG. 13B. Furthermore, in FIG. 13A to FIG. 13F, although each pair of pads FP is connected to the light-emitting unit LED in an end-to-end structure, in practice, based on the description of the aforementioned embodiments, the different types of pads FP in FIG. 13A to FIG. 13F of the present invention can be applied to an edge-to-edge lateral connection structure similar to FIG. 12C.

In addition, the area around the low-power light-emitting unit is the area with the highest brightness. Expanding the light reflection angle in this area is the key to increasing the amount of light entering the side of the light guide plate, improving the lateral transmission ratio, and promoting the uniformity of light emission. However, the area around the light-emitting unit is the physical connection area between the light-emitting unit LED and the light board LCB line. How to make the electrical connection structure of the light-emitting unit LED and the light board LCB line simultaneously expand the light reflection angle is a major issue in the design of the light-emitting unit LED electrical connection structure.

Please refer to Figures 14A/14B/14C. Figure 14A is a partial top view schematic diagram of the optical structure of the backlight module in the area around the light-emitting unit in another embodiment of the present invention. Figure 14B is a partial cross-sectional schematic diagram of the backlight module in the embodiment of Figure 14A. Figure 14C is a partial top view schematic diagram of the optical structure of the backlight module in the area around the light-emitting unit in another embodiment of the present invention. Figure 14D is a partial top view schematic diagram of the optical structure of the backlight module of the derivative embodiment of Figure 14A of the present invention.

In FIG. 14A and FIG. 14B, the height difference between the six branch lines Br and the four hollow areas Ha/Hb of the two pads FP produces a concave-convex structure, and the reflective first reflective layer RL1 covers the entire area of each pad FP, so that the core microstructure area cMS surrounding at least a part of the light-emitting unit LED can be formed, wherein the concave area (hollow area Ha/Hb) and the convex area (branch line Br) can play the role of the microstructure area MS respectively. These pads FP and the core microstructure area cMS are located below the reflective part RL0 inside the light shielding plate SS. Even if there is no special pad FP and its hollow area Ha/Hb and branch line Br, as long as the first reflective layer RL1 covering the light-emitting unit LED has the aforementioned concave-convex structure, the core microstructure area cMS can still be formed around the light-emitting unit LED. Therefore, one or more core microstructure regions cMS surrounding the light-emitting unit LED can further reflect and diffuse the light reflected downward by the internal reflection part RL0 of the light shielding plate SS upward, increase the amount of side light entering the light guide plate hole L0, and thus improve the lateral transmission ratio and promote the overall light uniformity of the key KS and the light-emitting keyboard LKB.

From the overall structure, with the light-emitting unit LED as the center, the backlight module BLM of the embodiment of the present invention provides a plurality of light-distributing zones for achieving a light-distributing uniform effect, and the plurality of light-distributing zones of the backlight module BLM at least include a first zone Z1 and a second zone Z2. The first zone Z1 surrounds the light-emitting unit LED, and the first zone Z1 includes an inner ring portion RL1i of the first reflective layer RL1 and a pair of welding pads FP, which are located on the lamp board LCB for connecting the light-emitting unit LED, and the inner ring portion RL1i of the first reflective layer RL1 at least partially covers the welding pad FP, so that the inner ring portion RL1i of the first reflective layer RL1 reflects and diffuses the light of the light-emitting unit LED. The second zone Z2 surrounds the first zone Z1. The second zone Z2 includes a pair of microstructure regions MS spaced apart from each other and located on the first reflective layer RL1. The pair of microstructure regions MS surround the pair of pads FP together. The pair of microstructure regions MS reflects and diffuses the light transmitted by the light-emitting unit LED through the first zone Z1.

The first zone Z1 closest to the light-emitting unit LED provides one or more core microstructure regions cMS around the light-emitting unit LED through the two pads FP on the lamp board LCB and the first reflective layer RL1. The combination of the branch line Br and the hollow area Ha/Hb makes the first zone Z1 have a concave-convex structure. Since the pad FP and its core microstructure region cMS overlap at least partially with the internal reflective part RL0 of the light shielding plate SS in the Z direction, they can be used to reflect, diffuse and open the angle of the light from the internal reflective part RL0, and incident toward the side of the light guide plate hole L0. In the first zone Z1, the reflective layer hole RLH1 may overlap the two pads FP and their hollow areas Ha/Hb, the branch line Br and the core microstructure area cMS, and the light guide plate hole L0 may also overlap the two pads FP and their hollow areas Ha/Hb, the branch line Br and the core microstructure area cMS.

Secondly, the second zone Z2 surrounds the light emitting unit LED at a further distance, and also surrounds the light guide plate hole L0 and the reflective layer hole RLH1. The second zone Z2 includes two internal microstructure regions IMS separated by a pair of non-intersecting (sub) conductors STa/STb on the lamp board LCB (refer to FIG. 3, FIG. 10 and FIG. 11 of the aforementioned embodiment together), and the two internal microstructure regions IMS are located on the upper surface of the first reflective layer RL1, and together surround at least a portion of the first zone Z1. Although the two internal microstructure regions IMS may only partially overlap the internal reflection part RL0 of the light shielding plate SS, and the light directly from the internal reflection part RL0 of S rarely reaches the internal microstructure region IMS, during the lateral transmission of light in the light guide plate LGP, the light with a smaller angle than the critical angle will not be able to continue to be totally reflected inside the light guide plate LGP and pass through the lower surface of the light guide plate LGP. These light rays that pass through can be recovered by the two internal microstructure regions IMS, and then incident on the light guide plate LGP through reflection diffusion to continue lateral transmission.

Furthermore, the backlight module BLM can be provided with a third zone Z3 between the first zone Z1 and the second zone Z2, and the third zone Z3 can overlap with the first zone Z1 and/or the second zone Z2 in the Z direction. The third zone Z3 mainly includes the glue layer Ah (such as the glue layer Ah1 and/or Ah2 in Figure 14B) provided above the light board LCB in Figure 14A. Although there is a need to use glue to position the layers of the backlight module BLM, the glue should also be taken into consideration in the optical design; first, the glue layer Ah1/Ah2 should be made of a light-transmitting glue material with good optical coupling. Although excessive concentration of light around the LED of the light-emitting unit is an original problem of low-brightness light-emitting units, it is also possible to make an overcorrection during implementation, for example, resulting in insufficient light from the inner light-transmitting area KC0 near the center of the keycap KCC in Figure 3. At this time, the use of glue layers Ah1/Ah2 can fine-tune and increase the light intensity as a means of post-correction. In detail, the adhesive layer Ah1 can be arranged on the upper surface of the light guide plate LGP (or between the light guide plate LGP and the light shielding plate SS) around the light guide plate hole L0, the reflective layer hole RLH1 and the light emitting unit LED, and the adhesive layer Ah2 can be arranged on the lower surface of the light guide plate LGP (or between the light guide plate LGP and the light board LCB) around the light guide plate hole L0, the reflective layer hole RLH1 and the light emitting unit LED.

The glue layers Ah/Ah1/Ah2 are not suitable to be too close to the light-emitting unit LED. On the one hand, the light coupling effect of the glue layers Ah/Ah1/Ah2 will make the light of the light-emitting unit LED too concentrated and unable to diffuse. On the other hand, if the glue layers Ah/Ah1/Ah2 come into contact with the light-emitting unit LED during the process, their viscosity may cause the light-emitting unit LED to peel off. Therefore, the glue layers Ah/Ah1/Ah2 must be used under proper control, including setting the glue-free area CA or reducing the glue layer width. The glue-free area CA can be set between the glue layer Ah/Ah1/Ah2 and the light guide plate hole L0, or between the glue layer Ah/Ah1/Ah2 and the reflective layer hole RLH1. In the Z direction, the glue-free area CA can be set on the upper surface of the light guide plate LGP (or between the light guide plate LGP and the light shielding plate SS), or the glue-free area CA can be set on the lower surface of the light guide plate LGP (or between the light guide plate LGP and the light board LCB). In practice, the glue layers Ah1/Ah2 can be set one by one, or both at the same time. The glue gap AP is another means of adjusting the glue layer Ah1/Ah2. If there is a need to increase the outline halo of the keycap KCC or the brightness of the outer characters (external light-transmitting area KC1) in a certain direction, a gel gap AP can be opened in the gel layer Ah1/Ah2 to correspond to the required direction or light-transmitting area. The gel gap AP can allow more light to continue to be transmitted horizontally outward smoothly, thereby improving the light output brightness in that direction.

In general, the first, second, and third zones cover different blocks and areas of the light-emitting unit LED in the 360-degree range from the Z direction. Due to the different configurations of the optical elements, the upward light output of the first, second, and third zones can be relatively close. In addition, there are other elements that can be used as adjustment means. For example, the microstructure area MS on the surface of the light guide plate LGP can be used in conjunction with the core microstructure area cMS, the internal microstructure area IMS, and the external microstructure area OMS of the first reflective layer RL1 of the light board LCB to increase the reflection and diffusion effects. In addition, covering the glue layer Ah1/Ah2 with the internal reflection part RL0 of the light shielding plate SS can also reduce the light loss caused by the glue layer Ah1/Ah2 and recycle the light. In addition, the aforementioned adhesive layer Ah1/Ah2 can be viewed from the Z direction. In FIG. 14A/14B, the light guide plate hole L0 is larger than the reflective layer hole RLH1 of the first reflective layer RL1, and the reflective layer hole RLH1 is larger than the light-emitting unit LED, that is, the wall of the reflective layer hole RLH1 surrounds the light-emitting unit LED and does not completely cover the two pads FP. In other words, the reflective layer hole RLH1 is located between the light-emitting unit LED and the light guide plate hole L0, and a portion of the first reflective layer RL1 (the innermost ring area) is located between the reflective layer hole RLH1 and the light guide plate hole L0. In this way, the two pads FP are at least partially exposed in the reflective layer hole RLH1. The exposure range of the pad FP directly affects the range of the light-emitting unit LED that can be smoothly connected despite the offset during the assembly. Therefore, exposing more pads FP can ensure that the light-emitting unit LED is smoothly connected to the pad FP. At the same time, exposing the pad FP means that there is no first reflective layer RL1 to provide reflection, but this does not mean that the reflective layer hole RLH1 cannot provide a reflective diffusion effect. First, since the pad FP is copper or copper alloy (or other alternative metals), the reflective layer hole RLH1 can provide a reflective diffusion effect in the light guide plate hole L0 through the branch line Br line segment exposed by the two pads FP (located between the light-emitting unit LED and the reflective layer hole RLH1). Secondly, the hollow areas of the exposed areas of the two pads FP (including the hollow areas Ha/Hb and the pad gap FG) usually expose the substrate of the light board LCB (located below the lines and pads FP). As long as the exposed upper surface of the substrate can reflect light, whether the upper surface of the substrate itself is reflective, or there is a metal solder/conductive layer there, or there is a colloid that ensures the fixation of the light-emitting unit LED, it can also provide a reflective diffusion effect.

Referring to Figure 14C, when the mass production yield rate has become stable, and the chipping accuracy, chipping temperature, conductive layer flow, and chipping offset of the light-emitting unit LED are well controlled, a smaller reflective layer hole RLH1 can be used. The smaller the reflective layer hole RLH1 is, even when the four sides of the light-emitting unit LED surround the hole wall of the reflective layer hole RLH1, the first reflective layer RL1 can almost fully cover the light board LCB within the range of the light guide plate hole L0, without exposing any part of the pad FP. At this time, the two completely covered pads FP, their branch lines Br and multiple hollow areas Ha/Hb can form multiple microstructures with complete shapes and larger areas, and constitute the core microstructure area cMS surrounding the light-emitting unit LED. The larger the area of the core microstructure region cMS, the more light can be diffused in the early stage, so that more light can enter smoothly from the side wall of the light guide plate hole L0. The core microstructure region cMS may be partially located within the range of the light guide plate hole L0, and partially located outside the hole wall of the light guide plate hole L0. Of course, the size and shape of the reflective layer hole RLH1 is similar to the light-emitting unit LED, or slightly larger than the light-emitting unit LED, which can also achieve a similar effect.

Based on the configuration of the aforementioned embodiment, in Figures 14A to 14C, a portion of the multiple branch lines Br of the two pads FP jointly surround at least a portion of the light guide plate hole L0; the multiple hollow areas Ha/Hb of the two pads FP jointly surround and/or overlap the reflective layer hole RLH1; the inner ring portion RL1i of a portion of the first reflective layer RL1 located between the reflective layer hole RLH1 and the light guide plate hole L0 respectively overlaps at least a portion of the two pads FP, so that the local first reflective layer RL1 exposed in the light guide plate hole L0 can form a concave-convex reflective diffusion structure together with the local pad FP, such as the core microstructure area cMS. Finally, although each pad FP in each embodiment of the present invention is used as an example to connect the (sub) conductors STa/STb, in actual applications, each pad FP can also be selectively directly connected to the (main) conductors HT/LT mentioned in the aforementioned embodiments and Figures 2 to 11 as needed.

Referring to FIG. 14D , the light-emitting unit LED is packaged with three-color chips to provide three-color light (such as red, green, and blue). In order to achieve a good light mixing effect for the three-color chips of the light-emitting unit LED, the aforementioned core microstructure region cMS surrounding the light-emitting unit LED is also formed in the inner ring portion RL1i of the first reflective layer RL1 (regardless of the presence of the aforementioned solder pad FP or the type of solder pad FP), so as to increase the light mixing effect of the three-color chips of the light-emitting unit LED by improving the reflection and diffusion effects. In addition, the arrangement of the three-color chips can be arranged in a long-side to long-side sequence. The advantage is that the light-emitting unit LED is shorter, and the component offset is less likely to interfere with the small-sized light guide plate hole L0, but the disadvantage is that the light mixing effect is poor; because the long side of the chip with a larger light output is blocked by the long side of the adjacent chip, it is not easy for different colors of light to be transmitted crosswise. Another method is shown in Figure 14D. Each long side of the three-color crystal is parallel to the long side of the entire light-emitting unit LED. That is, each long side of the three-color crystal is arranged along the Y direction, or the three-color crystal is arranged in a row with its short side facing the short side. In this way, the long sides of the crystals with larger light output and larger light output range are facing the X direction in the figure and overlapping and interlacing with each other, so that a better light mixing effect can be obtained in the two larger fan-shaped ranges in the X direction; at the same time, in the Y direction, because the short sides of the crystals are adjacent, the short sides of the crystals have a small light output and a small light output range, and the light blocked by the short sides of the crystals is also less, and the polarization problem caused is also smaller.

In summary, the embodiments provided in Figures 12A to 14C of the present invention solve the connection stability problem of the light-emitting unit and the problem of excessive light concentration in the vicinity of the light-emitting unit. In addition to using a solder pad with a hollow area to ensure that the light-emitting unit can still be connected smoothly when the component is offset, the solder pad and its hollow area are further used to form a light homogenization design in the first area with the first reflective layer; in addition, the light board is matched with the internal microstructure area in the second area, the glue layer and the glue-free area in the third area, and the present invention provides different light homogenization solutions for different blocks along the light path from the light-emitting unit to the outside, so that the character brightness and keycap halo of a single key, and even the entire keyboard range can achieve a high degree of uniformity.

The above is only the preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

LCB: Light Board

STa, STb: conductors

LED: light emitting unit

RL1: First reflection layer

RL0: internal reflection part

ML0: Internal mask part

IMS: Internal Microstructure Region

cMS: nuclear microstructure region

L0: light guide hole

Ah: glue layer

AP:Colloid gap

Br: branch line

CA: glue-free area

FG: Pad gap

Ha,Hb: hollow area

RL1i: Inner ring part

RLH1: Reflection layer hole

Claims (20)

A backlight module is used to illuminate at least one keycap, the backlight module comprises: a light-emitting unit; a light guide plate having a light guide plate hole to accommodate the light-emitting unit; and a lamp board having a pair of pads respectively connected to the light-emitting unit, the lamp board comprising a first reflective layer surrounding the light-emitting unit and at least partially covering the pair of pads; wherein each of the pair of pads has a plurality of branch lines and at least one hollow area, and the at least one hollow area overlaps at least a portion of the light-emitting unit. The backlight module as described in claim 1, wherein an inner ring of the first reflective layer at least partially covers the branch line and the hollow areas, and the inner ring partially reflects and diffuses the light of the light-emitting unit. The backlight module as described in claim 1, wherein the light panel further comprises a pair of spaced microstructure regions located on the first reflective layer, the pair of microstructure regions jointly surround the pair of solder pads, and the pair of microstructure regions reflect and diffuse the light transmitted by the light-emitting unit through the light guide plate. The backlight module as described in claim 1, wherein the lamp panel has two wires electrically connected to the welding plate respectively, and the lamp panel also includes a pair of microstructure areas spaced from each other and located on the first reflective layer, and the pair of microstructure areas do not overlap the two wires. The backlight module as described in claim 1, wherein at least one of the plurality of branch lines of the pair of pads is not completely covered by the first reflective layer, and an exposed portion of the branch line of each pad reflects and diffuses the light of the light-emitting unit. The backlight module as described in claim 1, wherein the light guide plate has a light guide plate hole for accommodating the light-emitting unit, and at least a portion of the first reflective layer is located in the light guide plate hole. A backlight module as described in claim 1, wherein the backlight module includes a shading plate, and the shading plate includes an internal reflection portion overlapping the first reflection layer. The backlight module as described in claim 1, wherein the plurality of branch lines of the pair of pads form a pair of parallel flat edges, and the short side of the light-emitting unit is smaller than the width of the pair of flat edges. A backlight module as described in claim 1, wherein at least one of the plurality of branch lines of the bonding pad surrounds at least a portion of the light guide plate hole. The backlight module as described in claim 1, wherein the first reflective layer has a reflective layer hole, and the at least one hollow area of the bonding pad surrounds and/or overlaps the reflective layer hole. The backlight module as described in claim 1, wherein the first reflective layer has a reflective layer hole, and the reflective layer hole is located between the light-emitting unit and the light guide plate hole. The backlight module as described in claim 1, wherein the first reflective layer has a reflective layer hole, and a portion of the first reflective layer overlapping the butt pad is located between the reflective layer hole and the light guide plate hole. The backlight module as described in claim 1, wherein the light-emitting unit comprises three chips to provide three-color light, and the three chips are arranged in sequence with their short sides facing each other. The backlight module as described in claim 1, wherein the light panel has two wires electrically connected to the welding plate respectively, and the first reflective layer covers the two wires. The backlight module as described in claim 14, wherein the light panel further comprises a pair of microstructure regions spaced apart from each other and located on the first reflective layer, and the two conductive lines are located between the pair of microstructure regions. The backlight module as described in claim 1, wherein the lamp panel has two sub-conductors respectively electrically connected to the butt welding plate, and the lamp panel also has two main conductors respectively electrically connected to the two sub-conductors. The backlight module as described in claim 16, wherein the light panel further comprises a pair of external microstructure regions spaced apart from each other and located on the first reflective layer, and the pair of external microstructure regions are respectively located outside the two main conductors. A backlight module is used to illuminate at least one keycap. The backlight module includes a light guide plate, a light unit and a lamp board. The backlight module defines a plurality of light-homogenizing regions to homogenize the light of the light unit. The plurality of light-homogenizing regions include: a first region surrounding the light unit. The first region includes an inner ring portion of a first reflective layer and a pair of welding pads. The pair of welding pads is located on the lamp board for connecting the light unit. The inner ring portion of the reflective layer at least partially covers the welding pad, and the inner ring portion of the first reflective layer reflects and diffuses the light of the light-emitting unit; and a second area surrounds the first area, and the second area includes a pair of microstructure areas spaced from each other and located on the first reflective layer, and the pair of microstructure areas jointly surround the welding pad, and the pair of microstructure areas reflect and diffuse the light of the light-emitting unit transmitted through the light guide plate. A luminous keyboard, comprising: a plurality of keys each having a key cap; and a backlight module as described in any one of claims 1 to 18, the backlight module being located below the plurality of keys. A light panel includes: two non-intersecting wires; a plurality of microstructure regions, two of which are separated from each other, and the two microstructure regions do not overlap with the two non-intersecting wires; a light-emitting unit located between the two microstructure regions; and a pair of pads electrically connecting the two non-intersecting wires and the light-emitting unit, the pair of pads having at least one branch line to form a pair of parallel flat edges, the pair of pads also having at least one hollow region, and the light-emitting unit overlaps at least a portion of the at least one hollow region of the pair of pads.