Keyboard backlight circuit and keyboard

Abstract

The invention discloses a keyboard backlight circuit and a keyboard, and relates to the technical field of keyboard backlight, and the keyboard backlight circuit comprises a main circuit and an LED circuit. The main line comprises a first line, and the first line comprises a first input line and a first output line; a plurality of LED circuits connected in parallel are connected between the first input line and the first output line, and each LED circuit comprises a branch circuit and a light emitting diode connected in series with the branch circuit; at least one of the branch circuit and the main circuit comprises a high-resistance part, the parts, except the high-resistance part, of the branch circuit and the main circuit are common parts, and the resistance of the high-resistance part per unit length is higher than that of the common part per unit length. The high-resistance part is used as the divider resistor of the light-emitting diode, so that the divider resistor does not need to be additionally arranged in a piece punching manner, the process can be simplified, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of keyboard backlight technology, and in particular to a keyboard backlight circuit and a keyboard. Background Art

[0002] Currently, some keyboards have a backlight function. A backlight keyboard can make the keyboard keys, panel, or key symbols glow, so that the user can clearly see the key letters even without turning on the lights at night.

[0003] The keyboard backlight circuit usually includes LEDs (light-emitting diodes) and physical voltage-divider resistors. Both the LEDs and the voltage-divider resistors need to be connected to the circuit board through punching. The process is relatively complicated, and the connection quality between each device and the circuit board needs to be guaranteed after punching, which is not conducive to ensuring the yield rate and reducing costs. On the other hand, the thickness of the physical resistors is usually high, usually exceeding 0.25mm. Using physical resistors is not conducive to reducing the overall thickness of the backlight.

[0004] Therefore, it is necessary to improve the prior art to overcome the above defects.

[0005] The above content is only used to help understand the technical solution of this application and does not constitute an admission that the above is prior art. Summary of the Invention

[0006] The object of the present invention is to provide a keyboard backlight circuit and a keyboard, so as to reduce the number of electronic components.

[0007] To achieve the above-mentioned object of the invention, in a first aspect, the present invention provides a keyboard backlight circuit, comprising:

[0008] A main circuit including a first circuit including a first input line and a first output line;

[0009] LED circuits, wherein a plurality of LED circuits are connected in parallel between the first input line and the first output line, and each LED circuit includes a branch line and a light-emitting diode provided on the branch line;

[0010] At least one of the branch line and the main line includes a high-resistance portion, and portions of the branch line and the main line other than the high-resistance portion are common portions, wherein a resistance per unit length of the high-resistance portion is greater than a resistance per unit length of the common portion.

[0011] In a second aspect, the present invention provides a keyboard backlight circuit, characterized in that it includes:

[0012] a main circuit, comprising a first circuit and a plurality of second circuits, wherein the first circuit comprises a first input line and a first output line, and the second circuit comprises a second input line and a second output line;

[0013] An LED circuit, wherein a plurality of parallel LED circuits are connected between the first input line and the first output line, each LED circuit comprising a branch line and a light-emitting diode provided on the branch line; each first circuit and the LED circuit connected thereto constitute a light-emitting module; a plurality of parallel light-emitting modules are connected between the second input line and the second output line, the first input line of the light-emitting module is connected to the second input line, and the first output line of the light-emitting module is connected to the second output line;

[0014] At least one of the branch line and the main line includes a high-resistance portion, and portions of the branch line and the main line other than the high-resistance portion are common portions, wherein a resistance per unit length of the high-resistance portion is higher than a resistance per unit length of the common portion.

[0015] Furthermore, the first input line includes a first input end, the first output line includes a first output end, the first input line includes a first input portion located between the first input end and the LED circuit closest to the first input end, and a first output portion located between the first output end and the LED circuit closest to the first output end;

[0016] The second input line includes a second input end, the second output line includes a second output end, the second input line includes a second input portion located between the second input end and the light emitting module closest to the second input end, and the second output line includes a second output portion located between the second output end and the light emitting module closest to the second output end;

[0017] At least one of the first input part, the first output part, the second input part, and the second output part is provided with the high-resistance part.

[0018] Furthermore, the first input line includes a first input end, the first output line includes a first output end, the first input line includes a first input part located between the first input end and the LED circuit closest to the first input end, and a first output part located between the first output end and the LED circuit closest to the first output end, and the first input part and / or the first output part are provided with the high-resistance part.

[0019] Furthermore, the resistance per unit length of the high-resistance portion is not less than twice the resistance per unit length of the other portions.

[0020] Furthermore, the main line and the branch line are both made of conductive paste, and the conductivity of the conductive paste used to make the high-resistance portion is lower than the conductivity of the conductive paste used to make the common portion.

[0021] Furthermore, the common parts are all made of the same conductive paste.

[0022] Furthermore, the cross-sectional area of the high-resistance portion is smaller than the cross-sectional area of the common portion of the circuit at the level where the high-resistance portion is located.

[0023] Furthermore, the ratio of the cross-sectional area of the high-resistance portion to the cross-sectional area of the normal portion of the circuit at the level where the high-resistance portion is located does not exceed 1 / 2.

[0024] Furthermore, the line width W2 of the high-resistance portion is smaller than the line width W1 of the normal portion of the circuit at the layer where the high-resistance portion is located.

[0025] Furthermore, the branch line is provided with the high-resistance portion, and a line width W2 of the high-resistance portion on the branch line is 0.1 mm to 1.5 mm.

[0026] Furthermore, the high resistance portion includes at least two first wire bodies arranged at intervals and a second wire body connected between two adjacent first wire bodies, and the two adjacent first wire bodies and the second wire body connected between the two adjacent first wire bodies are U-shaped as a whole.

[0027] Furthermore, the distance D between two adjacent first linear bodies may be 0.3 mm to 5 mm.

[0028] Furthermore, the branch line includes a first portion connected between the first input line and the light-emitting diode and a second portion connected between the first output line and the light-emitting diode, and the first portion and / or the second portion are provided with the high-resistance portion.

[0029] Furthermore, the high-resistance part is arranged on the branch line, and the current flowing out of the front LED line flows toward the side where the rear LED line is located. The closer the branch line is to the first input end of the first input line or the first output end of the first output line, the greater the resistance of the branch line.

[0030] Furthermore, the high resistance portion is provided on the branch line, and the current flowing out of the rear LED line flows toward the side where the front LED line is located. The closer the branch line is to the first input end of the first input line, the greater the resistance of the branch line.

[0031] Furthermore, the resistance per unit length of the common portion is 0.2 ohm / cm.

[0032] In a third aspect, the present invention provides a keyboard comprising the keyboard backlight circuit as described in any one of the above items.

[0033] Compared with the prior art, the present invention has the following beneficial effects: According to some embodiments of the present invention, the keyboard backlight circuit includes a main circuit and multiple parallel LED circuits, the LED circuit includes a branch circuit and a light-emitting diode connected in series with the branch circuit, at least one of the branch circuit and the main circuit includes a high-resistance portion, and the portion of the branch circuit and the main circuit other than the high-resistance portion is a common portion, and the resistance per unit length of the high-resistance portion is greater than the resistance per unit length of the common portion. By using the high-resistance portion as a voltage-dividing resistor for the light-emitting diode, there is no need to set up a voltage-dividing resistor by punching, which can simplify the process and reduce costs. In addition, since the resistance per unit length of the high-resistance portion is higher, a shorter length can bring a higher resistance value, which is convenient for wiring in a limited space and reduces the amount of conductive paste used, saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 1 is a schematic structural diagram of a keyboard backlight circuit according to some embodiments of the present invention. In the figure, the high-resistance part is arranged in the branch line.

[0035] Figure 2 1 is a schematic structural diagram of a keyboard backlight circuit according to some embodiments of the present invention. In the figure, the high-resistance part is provided in the first circuit.

[0036] Figure 3 yes Figure 1 Schematic diagram of the structure of the LED circuit.

[0037] Figure 4 1 is a schematic structural diagram of a keyboard backlight circuit according to some embodiments of the present invention. In the figure, the high-resistance part is provided in the second circuit.

[0038] Figure 5 1 is a schematic structural diagram of an LED circuit in some embodiments of the present invention. In the figure, the high-resistance part is provided in the first part of the branch line.

[0039] Figure 6 1 is a schematic structural diagram of an LED circuit in some embodiments of the present invention. In the figure, the high-resistance part is provided in the second part of the branch line.

[0040] Figure 7 Schematic diagram of the structure of LED circuits in some embodiments of the present invention. In the figure, all branch circuits are high-resistance parts.

[0041] Figure 8 Schematic diagram of the connection between the first input line and the LED circuit in some embodiments of the present invention.

[0042] Figure 9 It is a schematic structural diagram of a keyboard backlight circuit in some embodiments of the present invention.

[0043] Figure 10 It is a schematic structural diagram of a keyboard backlight circuit in some embodiments of the present invention. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some, rather than all, structures related to the present application are shown in the accompanying drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0045] As used herein, the terms "comprise," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0046] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] Some embodiments of the present invention propose a keyboard backlight circuit, which includes a main circuit and multiple LED circuits 3, each LED circuit 3 includes a branch circuit 30 and a light-emitting diode 31 arranged on the branch circuit 30, the main circuit is connected to the LED circuit 3, and the main circuit is used to access a high voltage (or positive voltage) to drive the light-emitting diode 31 to emit light.

[0048] In some embodiments, as Figure 1 and Figure 2As shown, the main circuit includes a first circuit, and the first circuit includes a first input line 1 and a first output line 2. The voltage of the first input line 1 is higher than the voltage of the first output line 2 to form a voltage difference between the two. Optionally, the first input line 1 is connected to a positive voltage (or high voltage). For example, the first input line 1 is connected to a power supply port, and the first output line 2 is grounded. A plurality of parallel LED circuits 3 are connected between the first input line 1 and the first output line 2 of each first circuit. The LED circuit 3 includes a branch line 30 and a light-emitting diode 31 provided on the branch line 30. When the first input line 1 inputs a high level, current flows from the first input line 1 to the branch line 30, and drives the light-emitting diode 31 to emit light. As shown Figure 3 As shown, Figure 3 Shown Figure 1 Schematic diagram of a single LED line 3, the branch line 30 includes a first part 30a connected between the first input line 1 and the light-emitting diode 31 and a second part 30b connected between the first output line 2 and the light-emitting diode 31, and the light-emitting diode is connected between the first part 30a and the second part 30b.

[0049] In other embodiments, Figure 4 As shown, the main circuit also includes a second circuit, and the second circuit includes a second input line 4 and a second output line 5. Optionally, the second input line 4 is used to access a positive voltage (or high voltage) to drive the light-emitting diode 31 to emit light. For example, the second input line 4 is connected to the power supply port, and the second output line 5 is grounded. Each first circuit and the LED circuit 3 connected thereto form a light-emitting module (for example, Figure 1 and Figure 2 The circuit shown can be considered as a light-emitting module), multiple light-emitting modules are connected in parallel between the second input line 4 and the second output line 5, the first input line 1 and the second input line 4 of the light-emitting module are connected, and the first output line 2 and the second output line 5 of the light-emitting module are connected.

[0050] At least one of the branch line 30 and the main line includes a high-resistance portion 32. The portion of the branch line 30 or the main line other than the high-resistance portion 32 is a common portion. The resistance per unit length of the high-resistance portion 32 is higher than the resistance per unit length of the common portion. That is, the branch line 30 and the main line are divided into the high-resistance portion 32 and other portions based on the resistance per unit length. The resistance per unit length of the line can be obtained by dividing the total resistance of the line by its total length. For example, the resistance per unit length of the high-resistance portion 32 can be obtained by dividing its resistance by its length.

[0051] Because high-resistance portion 32 has a higher resistance per unit length, it can function as a voltage-divider resistor connected in series with light-emitting diode 31. This eliminates the need for a separate voltage-divider resistor on branch line 30 through component placement, simplifying the process and reducing costs. Furthermore, because high-resistance portion 32 has a higher resistance per unit length, a shorter length can achieve a higher resistance value, facilitating wiring within limited space and reducing the amount of conductive paste used, thus saving costs.

[0052] Figure 1 and Figure 2 In the illustrated embodiment, the high-resistance portion 32 may be provided on the branch line 30 (e.g., the first portion 30a and / or the second portion 30b thereof), or on the first line (e.g., the first input line 1 and / or the first output line 2), or may be provided on both the branch line 30 and the first line. Figure 4 In the illustrated embodiment, the high-resistance portion 32 may be provided on one, two, or three of the branch line 30 (e.g., the first portion 30a and / or the second portion 30b thereof), the first line (e.g., the first input line 1 and / or the first output line 2), and the second line (e.g., the second input line 4 and / or the second output line 5).

[0053] In some embodiments, the branch line 30 is provided with a high resistance portion 32. Figure 3 Shown in Figure 1 Schematic diagram of a single LED circuit 3, in which the position of the high resistance part 32 is indicated by a thick solid line. Figure 3 In the embodiment shown, a high resistance portion 32 is provided in both the first portion 30a and the second portion 30b. The high resistance portion 32 and the light emitting diode 31 are connected in series to divide the voltage, thereby playing the role of a resistor. Figure 5 , the high resistance portion 32 can be provided separately on the first portion 30a, referring to Figure 6 , the high resistance portion 32 may also be provided separately on the second portion 30b.

[0054] In some embodiments, the first line is provided with a high resistance portion 32, such as Figure 2 As shown, Figure 2 In FIG. 3 , the position of the high resistance portion 32 is indicated by a thick solid line. It can be understood that although Figure 2 The medium-high resistance portion 32 is provided on the first input line 1 and the first output line 2 . However, in other embodiments, the high resistance portion 32 may also be provided only on the first input line 1 or the first output line 2 .

[0055] The first input line 1 includes a first input terminal 1a, which can be connected to the second input line 4 or connected to a high voltage. The first output line 2 includes a first output terminal 2a, which can be connected to the second output line 5 or connected to ground. The first input line 1 includes a first input portion 1b located between the first input terminal 1a and the LED circuit 3 closest to the first input terminal 1a, and a first output portion 2b located between the first output terminal 2a and the LED circuit 3 closest to the first output terminal 2a. Optionally, a high-resistance portion 32 is provided on the first input portion 1b and / or the first output portion 2b. By connecting the high-resistance portion 32 in series with multiple parallel-connected LED circuits 3, a high-resistance portion 32 with a smaller resistance can achieve a greater voltage dividing effect. Therefore, the amount of conductive paste used in the high-resistance portion 32 or the circuit complexity can be reduced, thereby lowering costs. For example, when there are 10 parallel LED circuits 3, providing a high-resistance portion 32 with a resistance of 10 ohms on the first circuit can achieve a voltage dividing effect equivalent to providing a high-resistance portion 32 with a resistance of 100 ohms on the branch circuit 30.

[0056] In some embodiments, the second line is provided with a high resistance portion 32, such as Figure 4 As shown, Figure 4 In FIG. 3 , the position of the high resistance portion 32 is indicated by a thick solid line. It can be understood that although Figure 4 The medium-high resistance portion 32 is provided on the second input line 4 and the second output line 5 . However, in other embodiments, the high resistance portion 32 may also be provided only on the second input line 4 or the second output line 5 .

[0057] The second input line 4 includes a second input terminal 4a, and the second output line 5 includes a second output terminal 5a. The second input terminal 4a can be used to connect to a positive voltage, and the second output terminal 5a can be used to connect to a ground. The second input line 4 includes a second input portion 4b located between the second input terminal 4a and the light-emitting module closest to the second input terminal 4a. The second output line 5 includes a second output portion 5b located between the second output terminal 5a and the light-emitting module closest to the second output terminal 5a. At least one of the first input portion 1b, the first output portion 2b, the second input portion 4b, and the second output portion 5b is provided with a high-resistance portion 32. In some embodiments, the second input portion 4b and / or the second output portion 5b is provided with a high-resistance portion 32, for example Figure 4In the embodiment, the second input portion 4b and the second output portion 5b are provided with a high-resistance portion 32. Since multiple light-emitting modules connected in parallel are connected between the second input portion 4b and the second output portion 5b, and each light-emitting module includes multiple light-emitting diodes connected in parallel, a greater voltage-dividing effect can be achieved by using the high-resistance portion 32 with a smaller resistance value, thereby reducing the amount of conductive paste used in the high-resistance portion 32 or the complexity of the circuit, thereby lowering costs. For example, when the number of light-emitting modules connected in parallel is 10, and each light-emitting module includes 10 parallel LED circuits 3, providing a high-resistance portion 32 with a resistance value of 1 ohm on the second circuit can achieve a voltage-dividing effect equivalent to providing a high-resistance portion 32 with a resistance value of 100 ohms on the branch circuit 30.

[0058] It can be understood that the high-resistance portion 32 can be set only on the first line, the second line or the branch line 30, or can be set on two or three of the first line, the second line and the branch line 30 at the same time, so as to further reduce the resistance value of the high-resistance portion 32 of each part, reduce the line complexity of the high-resistance portion 32 or the amount of conductive paste used.

[0059] The resistance per unit length of the circuit can be adjusted in many ways, for example, by changing the cross-sectional area or material of the circuit.

[0060] When the branch line 30 is provided with a high resistance portion 32, in some embodiments, the resistivity of each portion of the branch line 30 is higher than the resistivity of the ordinary portion, so as to increase the resistance per unit length of the branch line 30, so that the required resistance value can be obtained with a shorter line. Optionally, the branch line 30 is made of the same material, and the resistivity of each portion is consistent, which can be easily processed without changing the material to form the branch line 30 in batches. In this case, Figure 7 As shown, all branch lines 30 are high-resistance portions 32 , so the length of the branch lines 30 can be shorter, resulting in less consumption of the conductive paste.

[0061] In other embodiments, reference Figure 3 A portion of branch line 30 is a high-resistance portion 32, and branch line 30 also includes another portion 33 having a lower resistivity than high-resistance portion 32. It is understood that other portion 33 is part of the normal portion. Due to its short length and low resistivity, the resistance contributed by other portion 33 can be ignored. Of course, the resistance contributed by other portion 33 can also be included in the voltage divider resistance, that is, the resistance of the entire branch line 30 is used as the voltage divider resistance of light-emitting diode 31 to improve accuracy.

[0062] Optionally, the resistivity of the common parts is the same. Further, optionally, the common parts are made of the same material, and the common parts can be made of the same material, and then another material can be used to make the high-resistance part 32 to improve production efficiency.

[0063] Both the main and branch lines 30 are made of conductive paste. The resistivity of the lines can be adjusted by changing the material of the conductive paste. The higher the conductivity of the conductive paste, the lower the resistivity of the resulting line. When the conductivity of the conductive paste used to make the normal portion is higher than that of the conductive paste used to make the high-resistance portion 32, the resistivity of the high-resistance portion 32 is higher than that of the normal portion.

[0064] The conductivity of the conductive paste can be controlled by its components. In some embodiments, the conductive paste is made of silver paste. By changing the particle size, shape and purity of the silver powder, its conductivity is controlled, thereby controlling the resistance per unit length of the circuit produced.

[0065] It is understandable that the circuits (main circuits and branch circuits) of the keyboard backlight circuit can be divided into multiple levels, for example, Figure 1 and Figure 2 In the illustrated embodiment, the branch line 30 belongs to the first level, and the first lines (the first input line 1 and the first input line 2) belong to the second level. Figure 4 In the illustrated embodiment, the branch line 30 belongs to the first level, the first lines (first input line 1 and first input line 2) belong to the second level, and the second lines (second input line 4 and second output line 5) belong to the third level.

[0066] In some embodiments, the cross-sectional area of the high-resistance portion 32 is smaller than the cross-sectional area of the ordinary portion of the circuit at the same level, so that the resistance per unit length of the ordinary portion is smaller than the resistance per unit length of the high-resistance portion 32. Figure 3 As shown, the cross-sectional area of the high-resistance portion 32 of the branch line 30 is set to be smaller than the cross-sectional area of the other portions 33. As some feasible examples, the cross-sectional area of the ordinary portion on the line at the same level is larger than the cross-sectional area of the high-resistance portion 32, and the ordinary portion and the high-resistance portion 32 are both made of the same conductive paste. Since the cross-sectional area of the high-resistance portion 32 is smaller, its resistance per unit length is larger, and the same conductive paste can be used to prepare the main line and the branch line 30, which is beneficial to improving production efficiency. As some other feasible examples, the cross-sectional area of the ordinary portion on the line at the same level is larger than the cross-sectional area of the high-resistance portion 32, and the resistivity of the ordinary portion is smaller than the resistivity of the high-resistance portion 32. In this way, the resistance per unit length of the high-resistance portion 32 is larger, and a shorter length can bring the required voltage divider resistance, which is beneficial to saving conductive paste and reducing costs.

[0067] Optionally, the ratio of the cross-sectional area of the high-resistance portion 32 to the cross-sectional area of the ordinary portion of the circuit at the level where it is located does not exceed 1 / 2, so that it has a more appropriate resistance per unit length, and the required voltage divider resistance size can be obtained by a suitable length.

[0068] In some embodiments, as Figure 8 As shown, the line width W2 of the high-resistance portion 32 is smaller than the line width W1 of the ordinary portion of the circuit at the same level, which is beneficial for relatively increasing the cross-sectional area of the ordinary portion and relatively reducing the cross-sectional area of the high-resistance portion 32, thereby increasing the resistance of the high-resistance portion 32 per unit length. Generally, the better the conductivity of the conductive paste, the lower its adhesion to the circuit board. Therefore, making the ordinary portion wider can improve the firmness of its connection with the circuit board, making the keyboard backlight circuit as a whole more reliable. Optionally, when the branch line 30 is provided with a high-resistance portion 32, the line width W2 of the high-resistance portion 32 on the branch line 30 is 0.1mm to 1.5mm, so that it can reliably conduct electricity and have a higher resistance per unit length.

[0069] Optionally, the materials, cross-sectional areas, line widths and other parameters of the other parts are the same.

[0070] In some embodiments, the resistance per unit length of high-resistance portion 32 is not less than twice the resistance per unit length of the normal portion, making the length of high-resistance portion 32 relatively short, thereby reducing space occupied on the circuit board and facilitating the installation of other electronic components. Furthermore, optionally, the resistance per unit length of high-resistance portion 32 is not less than five times the resistance per unit length of the normal portion.

[0071] In some embodiments, the high resistance portion 32 is designed to increase its length and improve its resistance value. Figure 3 As shown, the high-resistance portion 32 includes at least two first wires 300 spaced apart and a second wire 301 connected between two adjacent first wires 300. The two adjacent first wires 300 and the second wire 301 connected between the two adjacent first wires 300 form a U-shape. This allows the length of the high-resistance portion 32 to be increased within a smaller space, thereby improving its resistance.

[0072] Optionally, the high-resistance portion 32 includes a plurality of first wire bodies 300 arranged at intervals, and the spacing D between two adjacent first wire bodies 300 is 0.3 mm to 5 mm. The width between the two first wire bodies 300 is relatively appropriate, which is convenient for wiring and helps to reduce the risk of the overall resistance value being reduced due to contact between adjacent first wire bodies 300.

[0073] It is understandable that the common parts of the first input line 1 and the first input line 2 also have a certain resistance. After participating in the voltage division of the light-emitting diode 31, this resistance will make the voltage divided by each light-emitting diode 31 inconsistent, thereby affecting the consistency of the light of each light-emitting diode 31.

[0074] In some embodiments, as Figure 9As shown, LED circuits 3 are arranged in intervals from front to back, with the front referring to a position relatively close to the first input terminal 1a of the first input line 1. Current flowing from the front LED circuit 3 flows sequentially toward the side of the rear LED circuit 3 until it flows out from the first output terminal 2a of the first output line 2. The first input terminal 1a of the first input line 1 and the first output terminal 2a of the first output line 2 are located on either side of the keyboard backlight circuit, respectively. Figure 9 In the illustrated embodiment, the closer the branch line 30 is to the first input terminal 1a of the first input line 1 or the first output terminal 2a of the first output line 2, the greater the resistance of the branch line 30. That is, among the multiple parallel branch lines 30, the closer the branch line 30 is to the end, the greater the resistance, and the closer to the middle, the smaller the resistance of the branch line 30. In this way, the total resistance of the circuit and the voltage divider of each light-emitting diode 31 can be made more consistent, which is conducive to improving the consistency of the brightness of each light-emitting diode 31. In some embodiments, by adjusting the resistance of the branch line 30, the current flowing through each light-emitting diode 31 is the same, thereby making the brightness of each light-emitting diode 31 consistent. Optionally, the resistance of the branch line 30 can be adjusted by adjusting the resistance of the high-resistance portion 32, that is, the resistance of the high-resistance portion 32 closer to the first input terminal 1a or the first output terminal 2a is set to be larger.

[0075] In some embodiments, as Figure 10 As shown, the LED circuits 3 are arranged in intervals from front to back. The front refers to a position relatively close to the first input terminal 1a of the first input line 1. The current flowing out of the LED circuit 3 in the back flows toward the side of the LED circuit 3 in the front, until it flows out of the first output terminal 2a of the first output line 2. The first input terminal 1a of the first input line 1 and the first output terminal 2a of the first output line 2 are located on the same side of the keyboard backlight circuit. The resistance of the branch circuit 30 closer to the first input terminal 1a increases. In other words, the resistance of multiple parallel branch circuits 30 gradually decreases from the first input terminal 1a to the first output terminal 2a. This ensures that the total resistance of the circuit and the voltage divided by each LED 31 is more consistent, which helps to improve the consistency of the brightness of each LED 31. In some embodiments, by adjusting the resistance of the branch circuit 30, the current flowing through each LED 31 is the same, thereby ensuring consistent brightness of each LED 31. Optionally, the resistance of the branch circuit 30 can be adjusted by adjusting the resistance of the high-resistance portion 32, that is, the resistance of the high-resistance portion 32 closer to the first input terminal 1a is set to be greater.

[0076] It is understood that the lower the resistance per unit length of the common portion, the smaller the difference in resistance between the portion connected in series with each LED 31, which can reduce the problem of uneven brightness of each LED 31 caused by impedance voltage division. Optionally, the resistance per unit length of the common portion is less than 0.2 ohm / cm.

[0077] Optionally, the LED circuits 3 are arranged at equal intervals, i.e., the spacing between two adjacent connections 3a is equal, and the spacing between two adjacent connections 3b is also equal. Connection 3a refers to the connection location between the LED circuit 3 and the first input line 1, and connection 3b refers to the connection location between the LED circuit 3 and the first output line 2.

[0078] The present invention further provides a keyboard, which includes the keyboard backlight circuit as described above. The keyboard may be, for example, a keyboard of an electronic device such as a mobile phone, a notebook or a desktop computer.

[0079] The present invention further provides an electronic device, including the keyboard backlight circuit or keyboard as described above. The electronic device may be, for example, a mobile phone, a notebook, a desktop computer, or other electronic device with multiple buttons.

[0080] It should be noted that, in the absence of conflict, the various embodiments in this document can be combined with each other to obtain more implementation plans.

[0081] The above is only a specific embodiment of the present invention, and any other improvements made based on the concept of the present invention are considered to be within the protection scope of the present invention.

Claims

1. A keyboard backlight circuit, characterized in that: include: A main circuit, comprising a first circuit, wherein the first circuit comprises a first input line (1) and a first output line (2); LED circuits (3), wherein a plurality of LED circuits (3) are connected in parallel between the first input line (1) and the first output line (2), and each LED circuit (3) comprises a branch line (30) and a light-emitting diode (31) provided on the branch line (30); At least one of the branch line (30) and the main line includes a high-resistance portion (32); portions of the branch line (30) and the main line other than the high-resistance portion (32) are common portions; and a resistance per unit length of the high-resistance portion (32) is greater than a resistance per unit length of the common portion.

2. A keyboard backlight circuit, characterized in that: include: A main circuit, comprising a first circuit and a plurality of second circuits, wherein the first circuit comprises a first input line (1) and a first output line (2), and the second circuit comprises a second input line (4) and a second output line (5); An LED circuit (3), wherein a plurality of parallel LED circuits (3) are connected between the first input line (1) and the first output line (2), and each LED circuit (3) comprises a branch line (30) and a light-emitting diode (31) provided on the branch line (30); each first circuit and the LED circuit (3) connected thereto form a light-emitting module, and a plurality of parallel light-emitting modules are connected between the second input line (4) and the second output line (5), wherein the first input line (1) and the second input line (4) of the light-emitting module are connected, and the first output line (2) of the light-emitting module is connected to the second output line (5); At least one of the branch line (30) and the main line includes a high-resistance portion (32); portions of the branch line (30) and the main line other than the high-resistance portion (32) are common portions; and a resistance per unit length of the high-resistance portion (32) is higher than a resistance per unit length of the common portion.

3. The keyboard backlight circuit according to claim 2, wherein: The first input line (1) includes a first input end (1a), the first output line (2) includes a first output end (2a), the first input line (1) includes a first input portion (1b) located between the first input end (1a) and the LED circuit (3) closest to the first input end (1a), and a first output portion (2b) located between the first output end (2a) and the LED circuit (3) closest to the first output end (2a); The second input line (4) includes a second input end (4a), the second output line (5) includes a second output end (5a), the second input line (4) includes a second input portion (4b) located between the second input end (4a) and the light emitting module closest to the second input end (4a), and the second output line (5) includes a second output portion (5b) located between the second output end (5a) and the light emitting module closest to the second output end (5a); At least one of the first input part (1b), the first output part (2b), the second input part (4b) and the second output part (5b) is provided with the high resistance part (32).

4. The keyboard backlight circuit according to claim 1 or 2, characterized in that: The first input line (1) includes a first input end (1a), the first output line (2) includes a first output end (2a), the first input line (1) includes a first input portion (1b) located between the first input end (1a) and an LED circuit (3) closest to the first input end (1a), and a first output portion (2b) located between the first output end (2a) and an LED circuit (3) closest to the first output end (2a), and the first input portion (1b) and / or the first output portion (2b) are provided with the high-resistance portion (32).

5. The keyboard backlight circuit according to claim 1 or 2, characterized in that: The resistance per unit length of the high-resistance portion (32) is not less than twice the resistance per unit length of the other portions.

6. The keyboard backlight circuit according to claim 1 or 2, wherein: The main line and the branch line are both made of conductive paste, and the conductivity of the conductive paste used to make the high-resistance part (32) is lower than the conductivity of the conductive paste used to make the common part.

7. The keyboard backlight circuit according to claim 6, wherein: The common parts are all made of the same conductive paste.

8. The keyboard backlight circuit according to claim 1 or 2, characterized in that: The cross-sectional area of the high-resistance portion (32) is smaller than the cross-sectional area of the common portion of the circuit at the level where the high-resistance portion (32) is located.

9. The keyboard backlight circuit according to claim 8, wherein: The ratio of the cross-sectional area of the high-resistance portion (32) to the cross-sectional area of the ordinary portion of the circuit at the level where the high-resistance portion (32) is located does not exceed 1 / 2.

10. The keyboard backlight circuit according to claim 1 or 2, characterized in that: The line width W2 of the high resistance portion (32) is smaller than the line width W1 of the ordinary portion of the circuit at the level where the high resistance portion (32) is located.

11. The keyboard backlight circuit according to claim 10, wherein: The branch line (30) is provided with the high-resistance portion (32), and the line width W2 of the high-resistance portion (32) on the branch line (30) is 0.1 mm to 1.5 mm.

12. The keyboard backlight circuit according to claim 1 or 2, characterized in that: The high-resistance portion (32) comprises at least two first linear bodies (300) arranged at intervals and a second linear body (301) connected between two adjacent first linear bodies (300), and the two adjacent first linear bodies (300) and the second linear body (301) connected between the two adjacent first linear bodies (300) are U-shaped as a whole.

13. The keyboard backlight circuit according to claim 12, wherein: The distance D between two adjacent first wire bodies (300) can be 0.3 mm to 5 mm.

14. The keyboard backlight circuit according to claim 1 or 2, characterized in that: The branch line (30) comprises a first portion (30a) connected between the first input line (1) and the light-emitting diode (31) and a second portion (30b) connected between the first output line (2) and the light-emitting diode (31), wherein the first portion (30a) and / or the second portion (30b) is provided with the high-resistance portion (32).

15. The keyboard backlight circuit according to claim 1 or 2, characterized in that: The high-resistance portion (32) is provided on the branch line (30), and the current flowing out of the front LED line (3) flows toward the side where the rear LED line (3) is located, and the resistance of the branch line (30) that is closer to the first input end (1a) of the first input line (1) or the first output end (2a) of the first output line (2) increases.

16. The keyboard backlight circuit according to claim 1 or 2, characterized in that: The high-resistance portion (32) is provided on the branch line (30), and the current flowing out of the rear LED line (3) flows toward the side where the front LED line (3) is located, and the resistance of the branch line (30) closer to the first input end (1a) of the first input line (1) increases.

17. The keyboard backlight circuit according to claim 1 or 2, characterized in that: The resistance per unit length of the common portion is less than 0.2 ohm / cm.

18. A keyboard, characterized in that: Comprising the keyboard backlight circuit according to any one of claims 1 to 17.

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