Keyboard backlight

Abstract

A keyboard backlight device. The keyboard backlight device includes a circuit board, a package, and a light-emitting module. The circuit board has a board surface. The package is disposed on the board surface. The package includes a first output terminal, a second output terminal, and a driving circuit. The driving circuit is coupled to the first output terminal and the second output terminal and outputs a driving voltage to the first output terminal. The light-emitting module is disposed on the board surface and includes a first light-emitting unit. The first light-emitting unit includes a plurality of first light-emitting elements connected in series. The first light-emitting unit is coupled to the first output terminal and the second output terminal to form a first circuit. The driving circuit adjusts the driving voltage according to the number of the plurality of first light-emitting elements and the driving current.

Description

Technical Field

[0001] This utility model relates to a backlight device, and more particularly to a keyboard backlight device. Background Technology

[0002] As users increasingly use computers and laptops, they not only demand operational comfort but also continuously enhance the visual appeal of peripheral accessories. Taking keyboards as an example, users not only require comfortable operation but also demand visually appealing backlit effects. Utility Model Content

[0003] In view of this, a keyboard backlight device is provided in some embodiments. The keyboard backlight device includes a circuit board, a package, and a light-emitting module. The circuit board has a board surface. The package is disposed on the board surface. The package includes a first output terminal, a second output terminal, and a driving circuit. The driving circuit is coupled to the first output terminal and the second output terminal and is used to output a driving voltage to the first output terminal. The light-emitting module is disposed on the board surface and includes a first light-emitting unit. The first light-emitting unit includes a plurality of first light-emitting elements connected in series with each other. The first light-emitting unit is coupled to the first output terminal and the second output terminal to form a first circuit. The driving circuit is used to adjust the driving voltage according to the number of the plurality of first light-emitting elements and the driving current.

[0004] In some embodiments, the first circuit has a target voltage based on the number of the plurality of first light-emitting elements, and the driving voltage is greater than or equal to the target voltage.

[0005] In some embodiments, the driving circuit includes a voltage control module. The voltage control module is coupled to the light-emitting module and is used to generate a control signal based on the current detection signal and the driving current. The driving circuit adjusts the driving voltage according to the control signal.

[0006] In some embodiments, the driving circuit includes a feedback module. The feedback module is coupled to the voltage control module and the light-emitting module, and is used to generate a current detection signal based on a current change in the loop current and the driving current.

[0007] In some embodiments, the driving circuit includes a switching module. The switching module is coupled to the voltage control module and the first output terminal, and is used to adjust the driving voltage at the first output terminal according to the control signal.

[0008] In some embodiments, the keyboard backlight device further includes a current control module. The current control module is disposed on the board surface and coupled to the second output terminal and the light-emitting module, and is used to adjust the drive current according to the current adjustment signal.

[0009] In some embodiments, the plurality of first light-emitting elements of the first light-emitting unit have different spacings from the first output terminal of the package. In response to the driving circuit outputting a driving voltage to the first output terminal, the brightness of the plurality of first light-emitting elements is the same.

[0010] In some embodiments, the light-emitting module further includes a second light-emitting unit. The second light-emitting unit includes a plurality of second light-emitting elements connected in series with each other. The second light-emitting unit is coupled to a first output terminal and a second output terminal to form a second circuit, and the second circuit is connected in parallel with the first circuit.

[0011] In some embodiments, the number of the plurality of first light-emitting elements is the same as the number of the plurality of second light-emitting elements.

[0012] In some embodiments, the plurality of first light-emitting elements of the first light-emitting unit have different spacings from the first output terminal of the package, and the plurality of second light-emitting elements of the second light-emitting unit have different spacings from the first output terminal of the package. In response to the driving circuit outputting a driving voltage to the first output terminal, the brightness of the plurality of first light-emitting elements and the plurality of second light-emitting elements is the same.

[0013] In summary, in some embodiments, the keyboard backlight device generates a lighting effect by mounting the package and the light-emitting module on a circuit board, which is then placed on the keyboard base. The light-emitting module includes a set of circuits (such as a first circuit). The package includes a driving circuit that dynamically adjusts the driving voltage based on the number of first light-emitting elements connected in series in the first circuit and the driving current. This ensures that all the first light-emitting elements in the first circuit can be illuminated, and each first light-emitting element has the same brightness.

[0014] The following detailed description of the features and advantages of this utility model in the embodiments is sufficient to enable anyone skilled in the art to understand the technical content of this utility model and implement it accordingly. Furthermore, based on the content disclosed in this specification, the claims, and the drawings, anyone skilled in the art can easily understand the related objectives and advantages of this utility model. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the keyboard backlight device in some embodiments of the present invention;

[0016] Figure 2 The circuit diagram of the keyboard backlight device in some embodiments of this utility model is shown below.

[0017] Figure 3 This is a schematic diagram of the light-emitting module of the keyboard backlight device in some embodiments of the present invention, showing that the light-emitting module is connected in parallel with multiple sets of light-emitting units;

[0018] Figure 4The present invention is illustrated in some embodiments as a block diagram of a keyboard backlight device, showing the driving circuit and current control module.

[0019] [Symbol Explanation]

[0020] 100: Keyboard backlight device

[0021] 102: Circuit Board

[0022] 104: Package

[0023] 106: Light-emitting module

[0024] 108: Plate surface

[0025] 110: First output terminal

[0026] 112: Second output terminal

[0027] 114: Power input terminal

[0028] 116: Drive circuit

[0029] 118: First light-emitting unit

[0030] 120: First light-emitting component

[0031] 122: Conductor

[0032] 124: Current Control Module

[0033] 126: Voltage control module

[0034] 127: First signal terminal

[0035] 128: Switch Module

[0036] 130: Feedback Module

[0037] 131: Second signal terminal

[0038] 132: Second light-emitting unit

[0039] 134: Second light-emitting element

[0040] Vin: Input voltage

[0041] L1: First circuit

[0042] L2: Second loop

[0043] R1: Current-limiting resistor Detailed Implementation

[0044] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 . Figure 1 This is a schematic diagram of the keyboard backlight device in some embodiments of the present invention. Figure 2 The present invention provides a circuit diagram of a keyboard backlight device in some embodiments. Figure 3 The present invention provides a schematic diagram of the light-emitting module of the keyboard backlight device in some embodiments, showing that the light-emitting module is connected in parallel with multiple sets of light-emitting units. Figure 4 The present invention is illustrated in some embodiments as a block diagram of a keyboard backlight device, showing the driving circuit and current control module.

[0045] In some embodiments, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the keyboard backlight device 100 includes a circuit board 102, a package 104, and a light-emitting module 106. The circuit board 102 has a board surface 108. The package 104 is disposed on the board surface 108. The package 104 includes a first output terminal 110, a second output terminal 112, and a driving circuit 116. The driving circuit 116 is coupled to the first output terminal 110 and the second output terminal 112, and is used to output a driving voltage to the first output terminal 110. The light-emitting module 106 is disposed on the board surface 108 and includes a first light-emitting unit 118. The first light-emitting unit 118 includes a plurality of first light-emitting elements 120 connected in series with each other. The first light-emitting unit 118 is coupled to the first output terminal 110 and the second output terminal 112 to form a first circuit L1. The driving circuit 116 is used to adjust the driving voltage according to the number of these first light-emitting elements 120 and a driving current.

[0046] In this embodiment, the keyboard backlight device 100 can be disposed below a keyboard base (not shown in the figure). Preferably, it can be combined with components such as a light guide plate, a reflector, and a light shield to conduct light. By illuminating the light-emitting module 106, light is emitted from each keyboard key to enhance the visual effect. This utility model is not limited to this, and the configuration of the backlight device 100 can be adjusted according to actual needs. The circuit board 102 can be a membrane circuit board, a printed circuit board (PCB), a flexible printed circuit board (FPCB), or a rigid-flex PCB, etc. The circuit board 102 has multiple wires 122 disposed on the board surface 108 to electrically connect the package 104 disposed on the board surface 108 and the light-emitting module 106. For example, the light-emitting module 106 can be surface-mounted to the board surface 108, and the first light-emitting elements 120 of the light-emitting module 106 are connected in series by the wires 122.

[0047] like Figure 2 and Figure 4 As shown. Package 104 can refer to a carrier that encapsulates multiple connection terminals (including a first output terminal 110 and a second output terminal 112) and a driving circuit 116 together. Package 104 solders the first output terminal 110 and the second output terminal 112 to the board surface 108 to be coupled to the light-emitting module 106 via wires 122. The second output terminal 112 can receive a ground voltage.

[0048] like Figure 2 As shown, the light-emitting module 106 is used to generate light when driven. The first light-emitting element 120 may be, for example, a light-emitting diode (LED), a micro light-emitting diode (Micro LED), an organic light-emitting diode (OLED), a quantum dot light-emitting diode (Quantum Dot LED), a mini light-emitting diode (Mini LED), or a polymer light-emitting diode (Polymer LED). Each of the first light-emitting elements 120 can be sequentially connected in series with each other via wires 122 to form a light string. The first first light-emitting element 120 is coupled to the first output terminal 110, and the last first light-emitting element 120 is coupled to the second output terminal 112 to form a first loop L1. When the first loop L1 is turned on, the first loop L1 has a loop current. This loop current may refer to the total current of the light-emitting module 106.

[0049] The driving circuit 116 can receive an input voltage Vin and adjust the driving voltage according to the number of the first light-emitting elements 120 and the driving current, so as to actuate the light-emitting module 106 to light up each of the first light-emitting elements 120 on the first circuit L1. Specifically, the first circuit L1 has a target voltage according to the number of the first light-emitting elements 120. When the number of first light-emitting elements 120 connected in series increases, the voltage (target voltage) actuating the first light-emitting unit 118 also increases. For example, the target voltage is the sum of the forward voltage (VF) of each first light-emitting element 120. Conversely, when the number of first light-emitting elements 120 connected in series decreases, the voltage actuating the first light-emitting unit 118 also decreases. Thus, the driving circuit 116 can dynamically adjust the driving voltage according to the number of first light-emitting elements 120, so that the driving voltage is greater than or equal to the target voltage, so that all the first light-emitting elements 120 in the first circuit L1 can be lit. Furthermore, the first light-emitting elements 120 in the first circuit L1 are connected in series with each other, and the circuit current of the first circuit L1 is a constant current. The driving circuit 116 can adjust the driving voltage according to the expected brightness setting, so that the loop current of the first circuit L1 reaches the driving current. In this way, each first light-emitting element 120 on the first circuit L1 can achieve the same brightness.

[0050] In some embodiments, the first light-emitting elements 120 of the first light-emitting unit 118 are spaced at different distances from the first output terminal 110 of the package 104. This distance can refer to the distance of each first light-emitting element 120 from the first output terminal 110 via the wire 122 according to their series connection order. In response to the driving circuit 116 outputting a driving voltage to the first output terminal 110, the brightness of these first light-emitting elements is the same. Specifically, each first light-emitting element 120 is connected in series via the wire 122, and the impedance value of each first light-emitting element 120 is affected by the length of the wire 122. The driving circuit 116 adjusts the driving voltage to drive the loop current of the first loop L1 to reach a set driving current. Even if the line impedance value of the first light-emitting elements 120 increases sequentially according to the number connected in series, the loop current in the first loop L1 is a constant current, and the brightness of each first light-emitting element 120 in the first loop L1 can be ignored due to the impedance effect of the wire 122. Thus, each first light-emitting element 120 achieves the same visual brightness.

[0051] In some embodiments, such as Figure 1 , Figure 2 , Figure 3 and Figure 4As shown. The keyboard backlight device 100 also includes a current control module 124. The current control module 124 is disposed on the board surface 108 and coupled to the second output terminal 112 and the light-emitting module 106. The current control module 124 is used to adjust the driving current according to a current adjustment signal. Specifically, the current control module 124 and the package 104 are both disposed on the board surface 108 and can be electrically connected to the package 104 via wires 122. The current control module 124 can receive a current adjustment signal and adjust the value of the driving current according to the current adjustment signal (the current adjustment signal can also be obtained by voltage signal conversion). In response to the adjustment of the driving current, the driving circuit 116 can adjust the driving voltage according to the reset driving current. Then, the loop current of the light-emitting module 106 (which can refer to the current of the first loop L1) can increase or decrease with the change of driving voltage to adjust the brightness of each first light-emitting element 120 on the first loop L1.

[0052] In some embodiments, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown. The driving circuit 116 includes a voltage control module 126. The voltage control module 126 is coupled to the light-emitting module 106 and is used to generate a control signal based on a current detection signal and a driving current. The driving circuit 116 adjusts the driving voltage according to the control signal. Specifically, the control signal can be a pulse-width modulation (PWM) signal. The current detection signal can refer to the real-time comparison of the loop current changes by the light-emitting module 106. The voltage control module 126 can dynamically adjust the driving voltage according to the changes in the loop current, so that the light-emitting module 106 can emit light stably. In some embodiments, the package 104 includes a power input terminal 114. The power input terminal 114 is coupled to the driving circuit 116 and is used to receive the input voltage Vin. Here, the driving circuit 116 can adjust the driving voltage output from the input voltage Vin to the first output terminal 110 according to the PWM signal. In some embodiments, the package 104 includes a first signal terminal 127. The first signal terminal 127 is coupled to the voltage control module 126 and is used to receive a clock signal. The voltage control module 126 can generate a pulse width modulation signal based on the clock signal.

[0053] In some embodiments, such as Figure 2As shown, the driving circuit 116 includes a switching module 128. The switching module 128 is coupled to the voltage control module 126 and the first output terminal 110, and is used to adjust the driving voltage at the first output terminal 110 according to a control signal. For example, the switching module 128 can be a metal-oxide-semiconductor field-effect transistor (MOSFET). One end of the switching module 128 is coupled to the first output terminal 110, and the other end is coupled to the second output terminal 112. A control terminal of the switching module 128 can receive a pulse width modulation signal to control the duty cycle of the first output terminal 110 and the second output terminal 112 of the switching module 128, thereby adjusting the input voltage Vin output to the driving voltage of the light-emitting module 106.

[0054] In some embodiments, such as Figure 2 and Figure 4 As shown, the driving circuit 116 includes a feedback module 130. The feedback module 130 is coupled to the voltage control module 126 and the light-emitting module 106, and is used to generate a current detection signal based on a current change between the loop current and the driving current. The feedback module 130 can measure the loop current of the light-emitting module 106 and compare the loop current with a current reference value to obtain the real-time change of the loop current. Then, the feedback module 130 can generate a current detection signal based on the comparison result to drive the voltage control module 126 to dynamically adjust the driving voltage according to the current detection signal. In some embodiments, the package 104 includes a second signal terminal 131. The second signal terminal 131 is coupled to the feedback module 130 and is used to receive the current detection signal.

[0055] In some embodiments, such as Figure 2 and Figure 4 As shown, the current control module 124 includes a current-limiting resistor R1. The current-limiting resistor R1 is coupled to the light-emitting module 106 and the second output terminal 112. The current-limiting resistor R1 is used to measure the loop current of the light-emitting module 106. The current-limiting resistor R1 can convert the loop current into a voltage signal, allowing the feedback module 130 to compare the measured voltage signal with the voltage value corresponding to the current reference value to generate a current detection signal. Since the current control module 124 is disposed on the board surface 108, the specifications of the current-limiting resistor R1 can be easily adjusted or replaced according to actual needs. In other embodiments, the current control module 124 may also be integrated into the package 104; this invention is not limited thereto.

[0056] In some embodiments, such as Figure 3As shown. The light-emitting module 106 also includes a second light-emitting unit 132. The second light-emitting unit 132 includes a plurality of second light-emitting elements 134 connected in series with each other. The second light-emitting unit 132 is coupled to the first output terminal 110 and the second output terminal 112 to form a second circuit L2, and the second circuit L2 is connected in parallel with the first circuit L1. The number of the first light-emitting elements 120 is the same as the number of the second light-emitting elements 134. Here, the circuit current of the light-emitting module 106 can be the sum of the current of the first circuit L1 and the current of the second circuit L2. For example, if the current of the first circuit L1 is 28 milliamperes (mA) and the current of the second circuit L2 is also 28mA, the circuit current of the light-emitting module 106 is 56mA. If the number of the first light-emitting elements 120 and the number of the second light-emitting elements 134 are both 7, then the target voltage of the first circuit L1 and the second circuit L2 is 21V (the forward conduction voltage is set to 3V). The power consumption of the light-emitting module 106 is 1.176W. Generally, if a parallel backlight board has the same number of light-emitting elements (e.g., 14 light-emitting elements), the conduction current of each light-emitting element is 28mA, and the loop current will be 392mA. If the driving voltage is 3V, the power consumption of the parallel backlight board is 1.176W. Therefore, the power consumption of the keyboard backlight device 100 and the parallel backlight board is the same. However, the power consumption of the keyboard backlight device 100 and the parallel backlight board via the current-limiting resistor R1 is different. For example, if the driving voltage is 5V, because the light-emitting module 106 of the parallel backlight board can only use 3V, the remaining 2V voltage difference will be wasted on the current-limiting resistor R1, and its wasted power is (392mA * 2V = 0.784W). The keyboard backlight device 100 we proposed uses a series driving method, resulting in a small loop current. Furthermore, the voltage across the current-limiting resistor R1 is set to a feedback voltage much lower than 2V (approximately 0.8V) due to the voltage adjustment module 126. Therefore, the virtual power consumption is approximately (56mA * 0.8V = 0.0448W). Compared to a parallel backlight panel, the keyboard backlight device 100 can achieve an energy saving effect of 0.7392W. In some embodiments, the parallel circuits of the light-emitting modules 106 can be increased to three or more circuits as needed, and the loop current can be deduced from the aforementioned examples.

[0057] In some embodiments, the second light-emitting elements 134 of the second light-emitting unit 132 have different spacings from the first output terminal 110 of the package 104. In response to the driving circuit 116 outputting a driving voltage to the first output terminal 110, the brightness of the first light-emitting elements 120 and the second light-emitting elements 134 is the same. Specifically, the first light-emitting unit 118 and the second light-emitting unit 132 are connected in parallel, and the target voltage of the first circuit L1 is equal to the target voltage of the second circuit L2. Here, the driving module 116 adjusts the driving voltage to drive the circuit current of the light-emitting module 106 (the sum of the currents in the first circuit L1 and the second circuit L2) to reach the driving current. Here, the impedance effect of the wire 122 can be ignored for each first light-emitting element 120 in the second circuit L1 and each second light-emitting element 134 in the second circuit L2, so that each first light-emitting element 120 and each second light-emitting element 134 achieves the same brightness.

[0058] In summary, in some embodiments, the keyboard backlight device 100 generates a light-emitting effect by placing the package 104 and the light-emitting module 106 on the circuit board 102, which is then placed on the keyboard base. The light-emitting module 106 includes a set of circuits (such as the first circuit L1). The driving circuit 116 of the package 104 can dynamically adjust the driving voltage according to the number of first light-emitting elements 120 connected in series on the first circuit L1 and the driving current. This ensures that all the first light-emitting elements 120 on the first circuit L1 can be lit, and each first light-emitting element 120 has the same brightness.

[0059] Although the technical content of this utility model has been disclosed above with reference to preferred embodiments, it is not intended to limit this utility model. Any modifications and refinements made by those skilled in the art without departing from the spirit of this utility model should be included within the scope of this utility model. Therefore, the scope of protection of this utility model shall be determined by the scope defined in the appended claims.

Claims

1. A keyboard backlight device, characterized in that, Include: A circuit board having a board surface; A package is disposed on the surface of the board. The package includes a first output terminal, a second output terminal and a driving circuit. The driving circuit is coupled to the first output terminal and the second output terminal and is used to output a driving voltage to the first output terminal. as well as A light-emitting module is disposed on the surface of the board. The light-emitting module includes a first light-emitting unit, which includes a plurality of first light-emitting elements connected in series with each other. The first light-emitting unit is coupled to the first output terminal and the second output terminal to form a first circuit. The driving circuit is used to adjust the driving voltage according to the number of the plurality of first light-emitting elements and a driving current.

2. The keyboard backlight device as described in claim 1, characterized in that, The first circuit has a target voltage based on the number of the plurality of first light-emitting elements, and the driving voltage is greater than or equal to the target voltage.

3. The keyboard backlight device as described in claim 1, characterized in that, The driving circuit includes a voltage control module coupled to the light-emitting module, and is used to generate a control signal based on a current detection signal and the driving current. The driving circuit adjusts the driving voltage according to the control signal.

4. The keyboard backlight device as described in claim 3, characterized in that, The driving circuit includes a feedback module coupled to the voltage control module and the light-emitting module, and is used to generate the current detection signal based on a current change between the loop current and the driving current.

5. The keyboard backlight device as described in claim 3, characterized in that, The driving circuit includes a switching module coupled to the voltage control module and the first output terminal, and is used to adjust the driving voltage at the first output terminal according to the control signal.

6. The keyboard backlight device as claimed in claim 1, characterized in that, It also includes a current control module, which is disposed on the surface of the board and coupled to the second output terminal and the light-emitting module. The current control module is used to adjust the driving current according to a current adjustment signal.

7. The keyboard backlight device as claimed in claim 1, characterized in that, The plurality of first light-emitting elements of the first light-emitting unit have different spacings from the first output terminal of the package. In response to the driving circuit outputting the driving voltage to the first output terminal, the brightness of the plurality of first light-emitting elements is the same.

8. The keyboard backlight device as claimed in claim 1, characterized in that, The light-emitting module also includes a second light-emitting unit, which includes a plurality of second light-emitting elements connected in series with each other. The second light-emitting unit is coupled to the first output terminal and the second output terminal to form a second circuit, and the second circuit is connected in parallel to the first circuit.

9. The keyboard backlight device as described in claim 8, characterized in that, The number of the plurality of first light-emitting elements is the same as the number of the plurality of second light-emitting elements.

10. The keyboard backlight device as claimed in claim 9, characterized in that, The plurality of first light-emitting elements of the first light-emitting unit have different distances from the first output terminal of the package, and the plurality of second light-emitting elements of the second light-emitting unit have different distances from the first output terminal of the package; In response to the driving circuit outputting the driving voltage to the first output terminal, the brightness of the plurality of first light-emitting elements and the plurality of second light-emitting elements is the same.

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