Key device of backlight keyboard

Abstract

A key device of a backlight keyboard comprises a substrate, a thin film circuit board, a flexible circuit board, a key cap, a supporting module, at least one induction resistor and a light-emitting part. The thin film circuit board is arranged on the substrate and can generate a trigger signal after being pressed. The flexible circuit board comprises a lower laid copper circuit sheet arranged above the film circuit board, a base material sheet arranged above the lower laid copper circuit sheet, and an upper laid copper circuit sheet arranged above the base material sheet. And the key cap is positioned above the flexible circuit board and has light transmission. The supporting module comprises an elastic body which is arranged above the flexible circuit board and elastically supports and abuts against the key cap. And the inductive resistor is arranged on the upper copper laying circuit sheet. And the light-emitting part is arranged on the upper laid copper circuit sheet and can directly project light to the key cap.

Description

Technical Field

[0001] This invention relates to a keypad device, and more particularly to a keypad device for a backlit keyboard. Background Technology

[0002] A backlit keyboard, as disclosed in patent application number I681431, includes a light guide substrate, a support plate, multiple keycaps, multiple lifting connectors, and a circuit board. The light guide substrate, made of a light-guiding material, functions to guide light and includes multiple assembly structures for assembling the lifting connectors. A light-emitting element is disposed on one side of the bottom of the light guide substrate and projects light onto it. This light is transmitted upward through the light guide substrate to the bottom surface of the support plate and reflected back to the light guide substrate by a reflective layer. Therefore, this light can be concentrated and emitted upward from a perforated portion of the support plate and a cutout portion of the circuit board, thereby illuminating the keycaps to address low-light usage environments.

[0003] However, when light passes through the light guide substrate, some of the light is lost due to absorption and scattering by the material. At the same time, the reflective layer cannot actually achieve complete reflection, causing some light to be absorbed or scattered in other directions. Therefore, the light generated by the light-emitting element cannot be used efficiently, reducing the light-emitting effect of the keycap. Summary of the Invention

[0004] The purpose of this invention is to provide a key device for a backlit keyboard that can improve the backlighting effect of keycaps.

[0005] The backlit keyboard key device of the present invention includes a substrate, a thin-film circuit board, a flexible circuit board, keycaps, a support module, at least one sensing resistor, and a light-emitting element. The thin-film circuit board includes a lower circuit sheet disposed above the substrate, a middle partition disposed above the lower circuit sheet, and an upper circuit sheet disposed above the middle partition. The thin-film circuit board can generate a trigger signal upon pressing. The flexible circuit board includes a lower copper circuit sheet disposed above the upper circuit sheet, a substrate sheet disposed above the lower copper circuit sheet, and an upper copper circuit sheet disposed above the substrate sheet. The keycaps are located above the flexible circuit board and are light-transmitting. The support module includes a support member pivotally connected between the substrate and the keycaps, and an elastic body disposed above the flexible circuit board and elastically supporting the keycaps. The at least one sensing resistor is disposed on the flexible circuit board. The light-emitting element is disposed on the upper copper circuit sheet of the flexible circuit board and can directly project light onto the keycaps.

[0006] The keypad of the backlit keyboard of the present invention further includes a first transparent adhesive layer disposed between the lower circuit sheet and the middle partition sheet, and a second transparent adhesive layer disposed between the middle partition sheet and the upper circuit sheet.

[0007] The keypad of the backlit keyboard of the present invention further includes a lower cover film layer coated on the lower surface of the lower copper circuit board and an upper cover film layer coated on the upper surface of the upper copper circuit board.

[0008] The key device of the backlit keyboard of the present invention includes a thin film circuit board with a central through hole in the middle partition, a lower circuit board with a lower conductive portion corresponding to the central through hole, and an upper circuit board with an upper conductive portion corresponding to the central through hole and the lower conductive portion.

[0009] The key device of the backlit keyboard of the present invention includes a lower copper circuit sheet, a substrate sheet and an upper copper circuit sheet that together define a connection channel. The connection channel is aligned with the upper conductive part, the middle through hole and the lower conductive part. The elastic body of the support module has a protrusion aligned with the connection channel.

[0010] The key mechanism of the backlit keyboard of the present invention further includes a transparent protective adhesive covering the light-emitting element.

[0011] The beneficial effects of the present invention are as follows: by setting the light-emitting element on the upper surface of the flexible circuit board and exposing it directly to the upper surface of the copper circuit board, the light-emitting element can directly project light onto the keycap, which can greatly improve the light-emitting effect of the keycap. Attached Figure Description

[0012] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the accompanying drawings, wherein:

[0013] Figure 1 This is a perspective view of one embodiment of the keypad device of the backlit keyboard of the present invention;

[0014] Figure 2 This is an exploded perspective view of the embodiment described.

[0015] Figure 3 This is an exploded perspective view of a substrate, a thin-film circuit board, and a flexible circuit board according to the embodiment described.

[0016] Figure 4 This is an exploded perspective view of the flexible circuit board described in the embodiment;

[0017] Figure 5 This is a cross-sectional schematic diagram of the embodiment described;

[0018] Figure 6 yes Figure 5 A magnified view of a portion of the central area;

[0019] Figure 7 yes Figure 5 A magnified view of a portion of the left area; and

[0020] Figure 8 yes Figure 5 A magnified view of a section of the right-hand area. Detailed Implementation

[0021] See Figure 1 and Figure 2 An embodiment of the key device of the backlit keyboard of the present invention includes a substrate 1, a thin film circuit board 2, a flexible circuit board 3, a keycap 4, a support module 5, three sensing resistors 6, and a light-emitting element 7.

[0022] See Figure 3 The substrate 1 is made of metal and includes a top surface 11 and a plurality of connectors 12 protruding from the top surface 11.

[0023] See Figure 3 The substrate 1, the thin film circuit board 2, and the flexible circuit board 3 are stacked sequentially from bottom to top along a vertical direction Z.

[0024] See Figure 3 The thin-film circuit board 2 includes a lower circuit sheet 21 disposed above the substrate 1, a first transparent adhesive layer 22 disposed above the lower circuit sheet 21, a middle partition 23 disposed above the first transparent adhesive layer 22, a second transparent adhesive layer 24 disposed above the middle partition 23, and an upper circuit sheet 25 disposed above the second transparent adhesive layer 24. The thin-film circuit board 2 can generate a trigger signal by being pressed.

[0025] The lower circuit chip 21 is disposed on the top surface 11 of the substrate 1 and has a lower conductive portion 211.

[0026] The first transparent adhesive layer 22 is disposed between the lower circuit sheet 21 and the middle partition 23, and has a first through hole 221 whose position is aligned with the lower conductive part 211.

[0027] The partition 23 is disposed between the first transparent adhesive layer 22 and the second transparent adhesive layer 24, and has an intermediate through hole 231 that is aligned with the lower conductive part 211 and the first through hole 221.

[0028] The second transparent adhesive layer 24 is disposed between the middle partition 23 and the upper circuit piece 25, and has a second through hole 241 that is aligned with the lower conductive part 211, the first through hole 221 and the middle through hole 231.

[0029] The upper circuit sheet 25 is disposed above the second transparent adhesive layer 24 and has an upper conductive part 251 that is aligned with the lower conductive part 211, the first through hole 221, the intermediate through hole 231 and the second through hole 241.

[0030] When the upper circuit piece 25 of the thin film circuit board 2 is pressed, causing the upper conductive part 251 to contact the lower conductive part 211 downwards, the lower circuit piece 21 generates the trigger signal accordingly.

[0031] The lower circuit piece 21, the middle partition piece 23, and the upper circuit piece 25 together constitute an anti-ghosting circuit (not shown) to enable the backlit keyboard to have the function of anti-ghosting.

[0032] See Figure 3 and Figure 4 The flexible circuit board 3 includes a lower copper trace 31 disposed above the upper trace 25, a substrate 32 disposed above the lower copper trace 31, an upper copper trace 33 disposed above the substrate 32, a lower cover film 34 coated on the lower surface of the lower copper trace 31, and an upper cover film 35 coated on the upper surface of the upper copper trace 33.

[0033] The upper cover film 35 is formed by printing black ink on the upper surface of the upper copper-plated circuit sheet 33.

[0034] The lower cover film 34, the lower copper circuit sheet 31, the substrate sheet 32, the upper copper circuit sheet 33, and the upper cover film 35 together define a connecting channel 36 extending along the vertical direction Z (see figure). Figure 6 The position of the connecting channel 36 is aligned with the upper conductive part 251.

[0035] See Figure 2 The keycap 4 is located above the flexible circuit board 3 and has at least one light-transmitting area (not shown), which may be text, symbols or patterns.

[0036] See Figure 2 , Figure 5 and Figure 6The support module 5 includes a support member 51 pivotally connected between the connector 12 and the keycap 4 on the substrate 1, and an elastic body 52 disposed on the flexible circuit board 3 and elastically supporting the keycap 4. The elastic body 52 has a protrusion 521 aligned with the connection channel 36. When the user presses the keycap 4, the keycap 4 pushes downward against the elastic body 52, compressing the elastic body 52. ​​The protrusion 521 of the elastic body 52 passes downward through the connection channel 36 and presses downward against the upper surface of the upper circuit chip 25, causing the upper conductive part 251 to contact the lower conductive part 211 downward, and the lower circuit chip 21 generates the trigger signal accordingly.

[0037] See Figure 7 The sensing resistor 6 is disposed on the copper trace 33 on the flexible circuit board 3 and is used to control the brightness of the light-emitting element 7. Each sensing resistor 6 may be a carbon composite resistor, a carbon film resistor, a ceramic resistor, a metal element resistor, a metal film resistor, a thin film resistor, a metal foil resistor, a metal oxide film resistor, a thick film resistor, or a wirewound resistor.

[0038] It is worth noting that the number of sensing resistors 6 can be one, two, or more than three, and is not limited to this embodiment.

[0039] See Figure 2 , Figure 5 and Figure 8 The light-emitting element 7 is a light-emitting diode (LED) and is disposed on the upper copper circuit sheet 33 and spaced apart from the elastic body 52. ​​Therefore, the light-emitting element 7 is directly exposed to the upper surface of the flexible circuit board 3 and can directly project light onto the keycap 4, so that the light can be diffused outward through at least one light-transmitting area of ​​the keycap 4.

[0040] The upper copper circuit sheet 33, the substrate sheet 32, the lower copper circuit sheet 31, and the sensing resistor 6 together constitute a driving circuit for driving the light-emitting element 7 to emit light (not shown in the figure).

[0041] When manufacturing the backlit keyboard, depending on the specifications of the light-emitting element 7, the brightness of the light-emitting element 7 can be controlled by adjusting the number of sensing resistors 6 to create different resistance values, or by using sensing resistors 6 with different resistance values. For example, when the light-emitting element 7 uses a monochrome LED, only one sensing resistor 6 is needed to control its brightness, while when the light-emitting element 7 uses an RGB LED, three sensing resistors 6 are needed to control its brightness.

[0042] See Figure 2 , Figure 4 and Figure 8 The key mechanism of the backlit keyboard of the present invention further includes a transparent protective adhesive 8 covering the light-emitting element 7. The transparent protective adhesive 8 is used to protect the light-emitting element 7 to prevent it from being easily damaged due to direct exposure to the upper surface of the flexible circuit board 3.

[0043] In summary, the key device of the backlit keyboard of the present invention, through the light-emitting element 7 disposed on the upper copper circuit sheet 33 and directly exposed to the upper surface of the flexible circuit board 3, the light-emitting element 7 can directly project light onto the keycap 4, so that the light can be diffused outward through at least one light-transmitting area of ​​the keycap 4, which can greatly improve the light-emitting effect of the keycap 4, and thus can indeed achieve the purpose of the present invention.

[0044] However, the above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the present invention shall still fall within the scope of the present invention.

Claims

1. A keypad device for a backlit keyboard, characterized in that: Include substrate; A thin-film circuit board includes a lower circuit sheet disposed above the substrate, a middle partition disposed above the lower circuit sheet, and an upper circuit sheet disposed above the middle partition. The thin-film circuit board can generate a trigger signal by being pressed. A flexible circuit board includes a lower copper trace disposed above the upper trace, a substrate disposed above the lower copper trace, and an upper copper trace disposed above the substrate. The keycaps are located above the flexible circuit board and are light-transmitting; The support module includes a support member pivotally connected between the substrate and the keycap, and an elastic body disposed above the flexible circuit board and elastically supporting the keycap; At least one sensing resistor is disposed on the upper copper trace of the flexible circuit board; and The light-emitting element is disposed on the copper circuit sheet on the flexible circuit board and can project light directly onto the keycap.

2. The keypad device of the backlit keyboard according to claim 1, characterized in that: The thin-film circuit board further includes a first transparent adhesive layer disposed between the lower circuit sheet and the middle partition sheet, and a second transparent adhesive layer disposed between the middle partition sheet and the upper circuit sheet.

3. The keypad device of the backlit keyboard according to claim 1, characterized in that: The flexible circuit board further includes a lower cover film layer coated on the lower surface of the lower copper circuit sheet, and an upper cover film layer coated on the upper surface of the upper copper circuit sheet.

4. The keypad device of the backlit keyboard according to claim 1, characterized in that: The thin-film circuit board has a central through hole in the spacer, a lower circuit board has a lower conductive portion corresponding to the central through hole, and an upper circuit board has an upper conductive portion corresponding to the central through hole and the lower conductive portion.

5. The keypad device of the backlit keyboard according to claim 4, characterized in that: The lower copper circuit sheet, the substrate sheet, and the upper copper circuit sheet together define a connection channel. The connection channel is aligned with the upper conductive part, the middle through hole, and the lower conductive part. The elastic body of the support module has a protrusion aligned with the connection channel.

6. The keypad device of the backlit keyboard according to claim 1, characterized in that: It also includes a transparent protective adhesive covering the light-emitting element.

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