CN104992869B - Backlight module and keyboard including it - Google Patents

Abstract

The invention relates to a backlight module and a keyboard including the same. The backlight module includes a membrane switch layer, a flexible circuit board, a plurality of light sources and a light guide plate. The membrane switch layer has a connection unit, and the connection unit has a plurality of first lines and a plurality of second lines. The flexible circuit board has a plurality of third lines, and the third lines are electrically connected to the second lines. The light sources are arranged on the flexible circuit board, and these light sources are electrically connected to the third lines. The light guide plate has a plurality of holes for accommodating the light sources respectively. In the present invention, since the membrane switch layer provides circuits to electrically connect the flexible circuit board, the flexible circuit board can only be electrically connected to the outside through the membrane switch layer, so the flexible circuit board does not need to consider the circuit layout for external electrical connection . In this way, the shape of the flexible circuit board can be simplified, so that waste can be reduced during the cutting process of the flexible circuit board, and more flexible circuit boards can be cut from the same board.

Description

Backlight module and keyboard including it

technical field

The invention relates to a backlight module, and in particular to a backlight module suitable for a keyboard.

Background technique

As shown in FIG. 1 , the flexible printed circuit board 11 of the backlight module 10 of the traditional luminous keyboard usually has an extension 12 that is pulled out and extended separately to electrically connect to the connector of the system. However, in order to match the position of the connector joints of the system, the shape of the flexible circuit board 11 becomes complicated, resulting in excess waste after cutting the circuit board. In addition, in this design, the flexible circuit board 11 uses a connector joint 13 , and the membrane switch layer 14 also uses a connector joint 15 , which increases assembly complexity and manufacturing cost.

Therefore, it is urgent to propose a solution that can simplify the shape and circuit design of the flexible circuit board.

Contents of the invention

Therefore, the present invention provides a backlight module, which can simplify the shape and circuit design of the flexible circuit board.

In order to achieve the above purpose, the present invention proposes a backlight module suitable for a keyboard, including: a membrane switch layer, a flexible circuit board, a plurality of light sources and a light guide plate. The membrane switch layer has a first connection unit, the first connection unit has a plurality of first lines and a plurality of second lines; the flexible circuit board has a plurality of third lines, and the plurality of third lines are respectively electrically connected to the plurality of a second line; a plurality of light sources are arranged on the flexible circuit board, and the plurality of light sources are electrically connected to the plurality of third lines; the light guide plate has a plurality of holes, and the plurality of holes are used to respectively accommodate the plurality of light source.

As an optional technical solution, the flexible circuit board is located in the middle area of the membrane switch layer.

As an optional technical solution, the flexible circuit board is long; or the flexible circuit board is rectangular.

As an optional technical solution, the membrane switch layer further includes a main body, the first connection unit is electrically connected to the main body, the entire area of the flexible circuit board overlaps the main body, and after the first connection unit is folded back, the second A connection unit partially overlaps with the flexible circuit board.

As an optional technical solution, the flexible circuit board includes a board body and a second connection unit connected to the board body, the plurality of third lines are located on the second connection unit, and the second connection unit is connected to the first connection unit. The connection unit is electrically connected, and after the first connection unit and the second connection unit are folded back, the second connection unit overlaps with the board body.

As an optional technical solution, the first connection unit further includes a first layer, a second layer and a spacer layer, the plurality of first lines and the plurality of second lines are arranged on the first layer, and the spacer layer is located on the Between the first layer and the second layer, the spacer layer has a first opening, the second layer has a second opening, the positions of the first opening and the second opening correspond, and the plurality of first lines And the plurality of second circuits are exposed from the first opening and the second opening.

As an optional technical solution, the backlight module further includes conductive glue, and the conductive glue electrically connects the plurality of third lines of the flexible circuit board and the first opening through the first opening and the second opening. The plurality of first lines of the connection unit.

As an optional technical solution, the flexible circuit board is electrically connected to the outside only through the film barrier layer.

As an optional technical solution, the plurality of second lines include a first positive line and a first negative line, the plurality of third lines include a second positive line and a second negative line, and the first positive line is electrically connected to the first Two positive lines, and the first negative line is electrically connected to the second negative line.

As an optional technical solution, the plurality of light sources are arranged along the first direction, each light source has a light emitting surface, the light emitting surface faces a second direction or a third direction, and the second direction is opposite to the third direction.

As an optional technical solution, the light emitting surfaces of two adjacent light sources face the second direction and the third direction respectively.

In addition, the present invention also proposes a keyboard, including the above-mentioned backlight module.

In the backlight module of the present invention and the keyboard comprising it, since the membrane switch layer provides circuits to electrically connect the flexible circuit board, the flexible circuit board can be electrically connected to the outside only through the membrane switch layer, so the flexible circuit board does not need Special consideration should be given to the wiring layout of external electrical connections. In this way, the shape of the flexible circuit board can be simplified, so that waste can be reduced during the cutting process of the flexible circuit board, and more flexible circuit boards can be cut out from the same board.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Description of drawings

FIG. 1 shows the appearance of a flexible circuit board of a conventional backlight module;

FIG. 2A shows a schematic view of the back of a backlight module according to an embodiment of the present invention;

FIG. 2B is a schematic front view of the backlight module shown in FIG. 2A;

FIG. 2C illustrates a cross-sectional view of the backlight module of FIG. 2A along the direction 2C-2C';

FIG. 2D is a schematic diagram showing the first connection unit and the second connection unit in FIG. 2A being folded back;

FIG. 3A shows a schematic view of the back of a backlight module according to another embodiment of the present invention;

FIG. 3B is a schematic diagram showing the inversion of the first connection unit in FIG. 3A;

FIG. 3C is a cross-sectional view of the backlight module of FIG. 3B along the direction 3C-3C'.

detailed description

2A shows a schematic view of the back of the backlight module 100 according to an embodiment of the present invention, FIG. 2B shows a schematic front view of the backlight module 100 of FIG. 2A , and FIG. 2C shows the backlight module 100 of FIG. 2A along the direction 2C- Sectional view of 2C'. The backlight module 100 includes a plurality of light sources 110 , a membrane switch layer 120 , a flexible circuit board 130 , a conductive adhesive 135 (as shown in FIG. 2C ), a light guide plate 140 and a reflection sheet 150 .

As shown in FIG. 2B and FIG. 2C , the light source 110 is disposed on the flexible circuit board 130 . These light sources 110 are arranged along the first direction D1, and each light source 110 has a light-emitting surface 110u, and the light-emitting surface 110u faces the second direction D21 or the third direction D22, so as to emit light toward the second direction D21 and the third direction D22, wherein the second The direction D21 is substantially opposite to the third direction D22, and the first direction D1 is substantially perpendicular to the second direction D21 or the third direction D22. Since the light-emitting surfaces 110u of the two adjacent light sources 110 respectively face the opposite second direction D21 and third direction D22, the light-emitting range of the light source 110 can cover the entire membrane switch layer 120 along the second direction D21 and the third direction D22. In addition, the flexible circuit board 130 is located in the middle area of the membrane switch layer 120, so that the difference in the length of the light path between each light source 110 and the boundary of the backlight module 100 is reduced, and the light is evenly distributed.

2A and 2C, the membrane switch layer 120 includes a first connection unit 121 and a main body 122, wherein the first connection unit 121 is electrically connected to the main body 122, and a plurality of membrane switches (not shown) are located on the main body 122 without Located on the first connection unit 121. The flexible circuit board 130 includes a second connection unit 131 , wherein the first connection unit 121 is electrically connected to the second connection unit 131 . The first connection unit 121 of the membrane switch layer 120 has a plurality of first circuits 1211 and a plurality of second circuits 1212 . The second connection unit 131 of the flexible circuit board 130 has a plurality of third lines 1311 , and the third lines 1311 are electrically connected to the second lines 1212 . The light source 110 is electrically connected to the third lines 1311 , so that the light source 110 is electrically connected to the second line 1212 of the membrane switch layer 120 through the third lines 1311 to receive external power. In addition, in order to clearly present the components of each layer in the backlight module 100, FIG. 2C deliberately enlarges the components. In fact, the height of the backlight module 100 is about 0.3 millimeters (mm), and the overall height of the keyboard (the top surface of the keycap 180 to the bottom plate 160 bottom) the height is about 5mm.

In this embodiment, the second line 1212 and the third line 1311 are power lines, and a power source (not shown) can supply power to the light source 110 through the second line 1212 and the third line 1311 to drive the light source 110 to emit light. Furthermore, the number of the second lines 1212 is two in total, which are respectively the first positive line and the first negative line. The number of these third lines 1311 is two in total, which are the second positive line and the second negative line, wherein the first positive line is electrically connected to the second positive line, and the first negative line is electrically connected to the second negative line, so that the light source 110 can supply power to the second positive line and the second negative line of the flexible circuit board 130 through the first positive line and the first negative line to drive the light source 110 to emit light. In this embodiment, the flexible circuit board 130 is electrically connected to the outside only through the membrane switch layer 120, that is, the flexible circuit board 130 is not directly electrically connected to other components except the membrane switch layer 120. connect.

Since the membrane switch layer 120 provides circuits to electrically connect the flexible circuit board 130 , the flexible circuit board 130 does not need to consider the circuit layout for external electrical connection. In this way, the shape of the flexible circuit board 130 can be simplified (if the circuit layout for external electrical connection is to be considered, a more complex shape of the flexible circuit board needs to be specially designed), so that the flexible circuit board 130 can be cut out of the board material. The cutting stage can reduce the generation of waste materials, and allow more flexible circuit boards 130 to be cut out from the same board. In this embodiment, the flexible circuit board 130 is in the shape of a strip, such as a rectangle, but it can also be other polygons.

As shown in Figure 2C, the first connection unit 121 includes a first layer 1213, a second layer 1214, and a spacer layer 1215, wherein the first circuit 1211 (not shown in Figure 2C) and the second circuit 1212 can be formed on the first layer 1213 superior. The spacer layer 1215 is located between the first layer 1213 and the second layer 1214, the spacer layer 1215 has a first 1215a, the second layer 1214 has a second opening 1214a, the first opening 1215a corresponds to the second opening 1214a, the second A circuit 1211 and a second circuit 1212 are exposed from the first opening 1215a and the second opening 1214a. In addition, the elastic body is omitted in FIG. 2C , and the elastic body is used to provide the key restoring force and trigger the switch on the membrane switch layer 120 .

The conductive glue 135 is formed in the first opening 1215a and the second opening 1214, and electrically connects the second line 1212 and the third line 1311 through the first opening 1215a and the second opening 1214a, so that the electric power can pass through the second opening 1214a. The second line 1212 and the third line 1311 are transmitted to the light source 110 to drive the light source 110 . In one embodiment, the conductive adhesive 135 is, for example, Anisotropic Conductive Film (ACF). As shown in FIG. 2C, since the second circuit 1212 and the third circuit 1311 are electrically connected through the first opening 1215a and the second opening 1214a outside the main body 122, any holes can be avoided in the main body 122, which can simplify The design of the main body 122 .

As shown in Figure 2C, the light guide plate 140 is arranged between the flexible circuit board 130 and the membrane switch layer 120, the light L1 of the light source 110 passes through the guide of the light guide plate 140, and shoots to the keycap 180, and the reflective sheet 150 is arranged on the guide. The bottom of the light plate 140 is used to reflect the light overflowing from the lower surface of the light guide plate 140 back into the light guide plate 140 . In addition, the light guide plate 140 has a plurality of holes 140 a (only one is shown in FIG. 2C ), which are respectively used to accommodate a plurality of light sources 110 .

As shown in FIG. 2C , the backlight module 100 can be combined with the bottom plate 160 , at least one supporting mechanism 170 and at least one keycap 180 to form a keyboard together, wherein the bottom plate 160 is disposed between the membrane switch layer 120 and the supporting mechanism 170 . The supporting mechanism 170 connects the bottom plate 160 and the keycap 180 to lift the keycap 180 so that the keycap 180 can move up and down, so that the keycap 180 moves between the unpressed position and the pressed position relative to the metal bottom plate. As shown in FIG. 1C , the supporting mechanism 170 is, for example, a scissor mechanism.

FIG. 2D is a schematic diagram of folding the first connection unit 121 and the second connection unit 131 in FIG. 2A . In order to reduce the area of the backlight module 100 , the first connection unit 121 and the second connection unit 131 can be folded back. As shown in the figure, the flexible circuit board 130 further includes a board body 132 , wherein the board body 132 is connected to the second connection unit 131 . After being folded back, the second connection unit 131 and the board body 132 of the flexible circuit board 130 overlap each other.

3A shows a schematic view of the back of a backlight module 200 according to another embodiment of the present invention, FIG. 3B shows a schematic view of the first connection unit 121 in FIG. Sectional view in direction 3C-3C'. The backlight module 200 includes a plurality of light sources 110 (not shown), a membrane switch layer 120 , a flexible circuit board 130 , a conductive glue 135 , a light guide plate 140 and a reflection sheet 150 .

The membrane switch layer 120 includes a first connection unit 121 and a main body 122 . Different from the backlight module 100 of the previous embodiment, the entire flexible circuit board 130 of this embodiment overlaps with the main body 122 of the membrane switch layer 120 . In detail, as shown in FIG. 3B , after the first connection unit 121 of the membrane switch layer 120 is folded back, the first connection unit 121 partially overlaps the flexible circuit board 130 .

As shown in FIG. 3C , the bottom plate 160 , the supporting mechanism 170 and the keycap 180 can be disposed on the membrane switch layer 120 , and their relative relationship is similar to that in FIG. 2C , so it will not be repeated here. In addition, similar to the structure shown in FIG. 2C, the first connection unit 121 of FIG. 3C includes a first layer 1213, a second layer 1214, and a spacer layer 1215, wherein the first circuit 1211 (not shown in FIG. 3C) and the second circuit 1212 is formed on the first layer 1213 . The spacer layer 1215 is located between the first layer 1213 and the second layer 1214, the spacer layer 1215 has a first opening 1215a, the second layer 1214 has a second opening 1214a, and the second line 1212 connects from the first opening 1215a to the second The opening 1214a is exposed. The conductive glue 135 electrically connects the second line 1212 and the third line 1311 through the first opening 1215a and the second opening 1214a, so that power (not shown) can be transmitted to the light source through the second line 1212 and the third line 1311 110. In addition, in order to clearly present the elements of each layer in the backlight module 100 , FIG. 3C intentionally enlarges the elements.

In the backlight module of the present invention and the keyboard comprising it, since the membrane switch layer provides circuits to electrically connect the flexible circuit board, the flexible circuit board can be electrically connected to the outside only through the membrane switch layer, so the flexible circuit board does not need Special consideration should be given to the wiring layout of external electrical connections. In this way, the shape of the flexible circuit board can be simplified, so that waste can be reduced during the cutting process of the flexible circuit board, and more flexible circuit boards can be cut out from the same board.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes All changes and modifications should belong to the scope of protection of the appended claims of the present invention.

Claims (12)

1. A backlight module suitable for a keyboard, characterized in that it comprises: The membrane switch layer has a first connection unit, and the first connection unit has a plurality of first lines and a plurality of second lines; The flexible circuit board has a plurality of third lines, and each of the plurality of third lines is electrically connected to the plurality of second lines, so that the flexible circuit board can be electrically connected to the outside only through the membrane switch layer; A plurality of light sources are arranged on the flexible circuit board, and the plurality of light sources are electrically connected to the plurality of third lines; and The light guide plate has a plurality of holes, and the plurality of holes are used to respectively accommodate the plurality of light sources. 2. The backlight module according to claim 1, wherein the flexible circuit board is located in the middle area of the membrane switch layer. 3. The backlight module according to claim 1, characterized in that: the flexible circuit board is long; or the flexible circuit board is rectangular. 4. The backlight module according to claim 1, wherein the membrane switch layer further comprises a main body, the first connection unit is electrically connected to the main body, the entire area of the flexible printed circuit overlaps the main body, and the reverse After folding the first connection unit, the first connection unit partially overlaps with the flexible circuit board. 5. The backlight module according to claim 1, wherein the flexible circuit board comprises a board body and a second connection unit connected to the board body, and the plurality of third lines are located on the second connection unit , the second connection unit is electrically connected to the first connection unit, and after the first connection unit and the second connection unit are folded back, the second connection unit overlaps with the board. 6. The backlight module according to claim 1, wherein the first connecting unit further comprises a first layer, a second layer and a spacer layer, the plurality of first lines and the plurality of second lines are arranged on The first layer, the spacing layer is located between the first layer and the second layer, the spacing layer has a first opening, the second layer has a second opening, the first opening and the second opening The positions of the holes correspond, and the plurality of first circuits and the plurality of second circuits are exposed from the first opening and the second opening. 7. The backlight module according to claim 6, characterized in that: the backlight module further comprises: The conductive adhesive electrically connects the plurality of third circuits of the flexible circuit board and the plurality of first circuits of the first connection unit through the first opening and the second opening. 8. The backlight module according to claim 1, wherein the flexible circuit board is electrically connected to the outside only through the membrane switch layer. 9. The backlight module according to claim 1, wherein the plurality of second lines include a first positive line and a first negative line, and the plurality of third lines include a second positive line and a second negative line , the first positive line is electrically connected to the second positive line, and the first negative line is electrically connected to the second negative line. 10. The backlight module according to claim 1, wherein the plurality of light sources are arranged along the first direction, each light source has a light-emitting surface, the light-emitting surface faces the second direction or the third direction, and the second direction The opposite of the third direction. 11. The backlight module according to claim 10, wherein the light-emitting surfaces of the two adjacent light sources face the second direction and the third direction respectively. 12. A keyboard, characterized in that it comprises: The backlight module as claimed in any one of claims 1-11.