Keyboard backlight circuit integrated with key detection function and driving method thereof

Abstract

The invention discloses a keyboard backlight circuit integrated with a key detection function and a driving method thereof, the keyboard backlight circuit comprises a plurality of scanning lines and a plurality of output lines, each scanning line is provided with a main line and a plurality of branch lines connected with the main line in parallel, the main line is provided with a first voltage end, the branch lines are provided with second voltage ends, and the second voltage ends are connected with the main line. A light emitting diode and a first resistor which are connected in series are sequentially arranged between the connection position of the branch line and the main line and a second voltage end, the second voltage end is electrically connected with a lighting control module, and the lighting control module is used for controlling the second voltage end to be grounded or suspended; the output line is provided with a voltage output end and a plurality of switching circuits connected with the scanning lines respectively, the switching circuits are connected with the portions, located between the light-emitting diodes and the first resistors, of the scanning lines, and the switching circuits comprise key switches. The second voltage end is selected to be grounded or suspended, and the scanning line is selected to be connected with a high level, so that more diversified light-emitting effects can be realized.

Description

Technical Field

[0001] The invention relates to an information input device, and in particular to a keyboard backlight circuit with integrated key detection function and a keyboard backlight circuit driving method. Background Art

[0002] With the development of technology, electronic devices are becoming more and more diversified. In order to achieve human-computer interaction, electronic devices are usually provided with buttons. For example, computers are often equipped with keyboards for typing, gaming and other operations.

[0003] Some keyboards have a backlight function, which is realized by the keyboard's backlight circuit. The backlight circuit is provided with a light-emitting diode corresponding to the key position, and the keyboard's backlight function is realized by controlling the light-emitting diode to emit light. Furthermore, in order to receive key information, the keyboard is also provided with a key detection circuit, which identifies which key is pressed through the key detection circuit. This results in the need to simultaneously set up a keyboard backlight circuit and a key detection circuit inside a keyboard with a backlight function, resulting in a complex circuit layout, a large number of circuit board layers or the need for multiple circuit boards to be stacked, and a large thickness, which ultimately results in a large thickness of the keyboard and a high cost.

[0004] In order to solve the above problems, the patent application number 2024114399190 filed by the applicant on October 15, 2024 discloses a keyboard backlight circuit with integrated key detection function, a keyboard backlight circuit driving method and a key input device (all the contents of which are incorporated herein by reference). By integrating the key detection circuit and the keyboard backlight circuit together, the circuit is simplified, thereby reducing the thickness of the keyboard.

[0005] However, the solution disclosed in the patent requires continuous scanning of each scan line input with a high level, otherwise key detection cannot be performed in real time. When the scan line is passed through a high level, its corresponding light-emitting diode will emit light, causing the keyboard backlight to only be always on, and it is impossible to achieve richer lighting effects such as flashing or lighting up in a certain order.

[0006] The above contents are only used to help understand the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0007] The object of the present invention is to provide a keyboard backlight circuit with integrated key detection function and a keyboard backlight circuit driving method, which can achieve richer lighting effects.

[0008] To achieve the above-mentioned object of the invention, in a first aspect, the present invention proposes a keyboard backlight circuit with integrated key detection function, characterized in that it comprises:

[0009] A plurality of scan lines, the plurality of scan lines are arranged at intervals, the scan lines have a main line and a plurality of parallel branches connected to the main line, the main line has a first voltage end, the branch line has a second voltage end, a light-emitting diode and a first resistor connected in series are sequentially arranged between the connection position between the branch line and the main line and the second voltage end, the light-emitting diode is used to realize keyboard backlighting, and makes the current unidirectionally conduct toward the first resistor, the second voltage end is electrically connected to a lighting control module, and the lighting control module is used to control the second voltage end to be grounded or suspended; and,

[0010] A plurality of output lines are arranged at intervals and staggered with the scan lines to form a matrix circuit, the output lines have voltage output terminals and a plurality of switch circuits respectively connected to the branches of the plurality of scan lines, each branch line is provided with a corresponding switch circuit, the switch circuit is connected to a portion of the branch line located between the light-emitting diode and the first resistor, and the switch circuit includes a key switch.

[0011] In some embodiments, the first voltage terminal and the voltage output terminal are both connected to the IO interface of the first chip, the first chip inputs a high level to the plurality of scan lines, and detects a voltage signal at the voltage output terminal of the output line.

[0012] In some embodiments, the lighting control module includes a second chip, the second voltage end is connected to the IO interface of the second chip, the second voltage end is controlled by the second chip to be grounded or suspended, and the first chip and the second chip are the same chip or two different chips.

[0013] In some embodiments, the switch circuit further includes a second resistor connected in series with the key switch.

[0014] In some embodiments, each of the second voltage terminals can be independently controlled to be grounded or suspended; or,

[0015] The second voltage terminals are divided into multiple groups. The second voltage terminals of each group can be controlled to be grounded or suspended at the same time, and at least one group includes at least two second voltage terminals.

[0016] In a second aspect, the present invention further proposes a keyboard backlight circuit driving method, which is performed by the keyboard backlight circuit with integrated key detection function as described in any one of the above items, and the keyboard backlight circuit driving method comprises the following steps:

[0017] S1. A high level of preset duration is applied to the first voltage terminals of the plurality of scanning lines in turn, and a high level is applied to the first voltage terminal of only one scanning line at the same time. The second voltage terminals corresponding to the light-emitting diodes that need to emit light are grounded according to the preset light-emitting sequence and light-emitting time, and the second voltage terminals corresponding to the light-emitting diodes that do not need to emit light are suspended.

[0018] In some embodiments, the keyboard backlight circuit driving method further includes the following steps:

[0019] S2. Detecting the voltage signal at the voltage output end of all the output lines during the high level period to determine whether the voltage is within a preset amplitude range;

[0020] S3. When the voltage signal at a voltage output terminal is detected to be within a preset amplitude range, the triggered key switch is determined based on the voltage conditions of the voltage output terminals of the plurality of output lines and the high-level scan lines;

[0021] In the step S3, judging the triggered key switch by combining the voltage conditions of the voltage output ends of the scan line and the plurality of output lines to which the high level is applied comprises the following steps:

[0022] S31. When the voltage signal at the voltage output end of a certain output line is detected to be within a preset amplitude range, a scanning line having a high level at the same time is obtained;

[0023] S32. Identify the key switch connected between the output line that meets the requirements and the scan line that is passed through a high level at the same time. The key switch is the triggered key switch. The output line that meets the requirements refers to the output line corresponding to the voltage output terminal whose detected voltage signal is within a preset amplitude value range.

[0024] In a third aspect, the present invention further proposes a keyboard backlight circuit driving method, which is performed by the keyboard backlight circuit with integrated key detection function as described in any one of the above items, and the keyboard backlight circuit driving method comprises the following steps:

[0025] A1. Driving the light emitting diode to emit light as needed in the first time period t10;

[0026] A2. Perform key detection in the second time period t11;

[0027] A3. Repeat steps A1 and A2 in sequence.

[0028] In some embodiments, in step A1, within the first time period t10, the second voltage terminal corresponding to the light-emitting diode that needs to emit light is grounded according to a preset light-emitting sequence and light-emitting time, and at the same time, a high level is passed to the first voltage terminal corresponding to the light-emitting diode that needs to emit light, and the second voltage terminal corresponding to the light-emitting diode that does not need to emit light is controlled to be suspended.

[0029] In some embodiments, step A2 comprises the following steps:

[0030] A21. sequentially pass a high level for a preset time length to the first voltage terminals of the plurality of scan lines, and pass a high level to the first voltage terminal of only one scan line at the same time;

[0031] A22. Detecting the voltage signals at the voltage output terminals of the plurality of output lines during the high level period, and determining whether there is a voltage signal whose voltage is within a preset amplitude range;

[0032] A23. When the voltage signal at a voltage output terminal is detected to be within a preset amplitude range, the triggered key switch is determined by combining the voltage conditions of the voltage output terminals of the high-level scan lines and the multiple output lines;

[0033] In the step A23, judging the triggered key switch by combining the voltage conditions of the voltage output ends of the scan lines and the multiple output lines to which the high level is applied comprises the following steps:

[0034] A231. When the voltage signal at the voltage output end of a certain output line is detected to be within a preset amplitude range, a scanning line having a high level at the same time is obtained;

[0035] A232. Identify the key switch connected between the output line that meets the requirements and the scan line that is fed with a high level at the same time. The key switch is the triggered key switch. The output line that meets the requirements refers to the output line corresponding to the voltage output terminal whose detected voltage signal is within the preset amplitude value range.

[0036] In a fourth aspect, the present invention proposes a keyboard backlight circuit driving method, which is performed by the keyboard backlight circuit with integrated key detection function as described in any one of the above items, and the keyboard backlight circuit driving method comprises the following steps:

[0037] B1. In the first preset time period, the light-emitting diodes that need to emit light are controlled to emit light according to the preset light-emitting time and light-emitting sequence, and only one scan line is passed to a high level at the same time;

[0038] B2. While the light-emitting diode is emitting light, the voltage signal at the voltage output terminal of the corresponding output line is detected to determine whether the key switch corresponding to the light-emitting diode is pressed;

[0039] B3. Determine whether all light emitting diodes have emitted light within the first preset time period. If so, repeat steps B1 to B3; if not, execute step B4;

[0040] B4. Perform key detection and then repeat steps B1 to B3.

[0041] In some embodiments, in step B1, the second voltage terminal corresponding to the LED that needs to emit light is controlled to be grounded, and a high level is applied to the first voltage terminal corresponding to the LED that needs to emit light, so that the LED that needs to emit light emits light.

[0042] In step B2, whether the key switch corresponding to the light-emitting diode is pressed is determined by judging whether the voltage is within the preset amplitude value range. When it is detected that the voltage signal at the voltage output end is within the preset amplitude value range, it indicates that the corresponding key switch is pressed.

[0043] In some embodiments, in step B3, determining whether all light emitting diodes have emitted light within the first preset time period includes the following steps:

[0044] Step B30. Determine whether all the scan lines are passed through the high level within the first preset time period. If not, it indicates that not all light emitting diodes have emitted light. If so, proceed to step B31.

[0045] Step B31. Determine whether all the second voltage terminals of all the scan lines that are passed through the high level are grounded when the high level is passed through. If not, it indicates that not all the light emitting diodes have emitted light. If so, it indicates that all the light emitting diodes have emitted light.

[0046] In some embodiments, in step B4, performing key detection includes the following steps:

[0047] B41. sequentially pass a high level for a preset time to the first voltage terminals of the plurality of scan lines, and pass a high level to the first voltage terminal of only one scan line at a time;

[0048] B42. Detecting the voltage signals at the voltage output terminals of the plurality of output lines during the high level period, and determining whether there is a voltage signal whose voltage is within a preset amplitude range;

[0049] B43. When the voltage signal at a voltage output terminal is detected to be within a preset amplitude range, the triggered key switch is determined by combining the voltage conditions of the voltage output terminals of the high-level scan lines and the multiple output lines;

[0050] In the step B43, judging the triggered key switch by combining the voltage conditions of the voltage output ends of the scan lines and the multiple output lines to which the high level is applied comprises the following steps:

[0051] B431. When the voltage signal at the voltage output end of a certain output line is detected to be within a preset amplitude value range, a scanning line having a high level at the same time is obtained;

[0052] B432. Identify the key switch connected between the output line that meets the requirements and the scan line that is passed through a high level at the same time. The key switch is the triggered key switch. The output line that meets the requirements refers to the output line corresponding to the voltage output terminal whose detected voltage signal is within the preset amplitude value range.

[0053] Compared with the prior art, the present invention has the following beneficial effects: according to some embodiments of the present invention, a switching circuit is connected in series in the keyboard backlight circuit, and the second voltage end of the branch of the scan line is connected to the lighting control module, so that the second voltage end can be switched between a grounded or suspended state, and by selecting the second voltage end to be grounded or suspended and selecting the scan line to pass a high level, the required light-emitting diodes can be illuminated, thereby achieving more diverse lighting effects and richer lighting effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 1 is a circuit diagram of a keyboard backlight circuit with integrated key detection function in some embodiments of the present invention.

[0055] Figure 2 yes Figure 1 The circuit shown is a schematic diagram for preventing false detection.

[0056] Figure 3 It is a schematic diagram of connecting the second voltage terminal to the second chip in some embodiments of the present invention.

[0057] Figure 4 It is a schematic diagram of connecting the second voltage terminal to the second chip in some embodiments of the present invention.

[0058] Figure 5 It is a circuit diagram of a keyboard backlight circuit with integrated key detection function in some embodiments of the present invention. In the diagram, a second resistor is provided in the switch circuit.

[0059] Figure 6 This is a timing diagram of passing a high level to each scanning line during key detection in some embodiments of the present invention, and the figure shows two scanning cycles.

[0060] Figure 7 It is a timing diagram of a lighting cycle of some embodiments of the present invention.

[0061] Figure 8 It is a timing diagram of a lighting cycle of some embodiments of the present invention. DETAILED DESCRIPTION

[0062] In order to make the above-mentioned purposes, 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 is to 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 structures related to the present application are shown in the accompanying drawings, rather than all structures. 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.

[0063] The terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0064] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0065] The present invention proposes a keyboard backlight circuit with integrated key detection function (hereinafter referred to as keyboard backlight circuit), which can be used in a keyboard or an electronic device with multiple keys. The keyboard backlight circuit can realize the backlight of the keyboard and can also detect the keys to determine which key of the device is pressed.

[0066] like Figure 1 As shown, a keyboard backlight circuit corresponding to an embodiment of the present invention includes a plurality of scan lines 10 and a plurality of output lines 11. The plurality of scan lines 10 are arranged at intervals, and the plurality of output lines 11 are also arranged at intervals. The scan lines 10 and the output lines 11 are arranged in an interlaced manner to form a matrix circuit. Figure 1 As shown, Figure 1The number of scan lines 10 and output lines 11 shown is 3. For the convenience of description, the three scan lines 10 from top to bottom are respectively referred to as the first scan line 10a, the second scan line 10b and the third scan line 10c, and the three output lines 11 from left to right are respectively referred to as the first output line 11a, the second output line 11b and the third output line 11c.

[0067] It should be noted that, herein, "plurality" or "multiple" or similar expressions indicate that the number is at least two, that is, "plurality" means two or more, therefore, in other embodiments, the number of the scan lines 10 and the output lines 11 may be two or more than three. It should be further noted that, although in the illustrated embodiment, the number of the scan lines 10 and the output lines 11 are the same, this is not necessarily the case, and the numbers of the two may be different, for example, one of them is two and the other is three, and so on.

[0068] The scanning line 10 has a first voltage terminal 100 and a second voltage terminal 101. The number of the second voltage terminals 101 can be multiple, for example Figure 1 In the illustrated embodiment, the scanning line 10 includes a main line 102 and a plurality of branch lines 103 connected to the main line 102. The plurality of branch lines 103 are arranged in parallel, each branch line 103 is provided with a second voltage terminal 101, and a light emitting diode and a first resistor are sequentially arranged between the connection position of the branch line 103 and the main line 102 and the second voltage terminal 101. The light emitting diode and the first resistor are connected in series. Figure 1 D1 to D9 are light emitting diodes, and R1 to R9 are first resistors. The light emitting diode allows the current to be unidirectionally conducted toward the second voltage terminal 101, that is, the current introduced into the first voltage terminal 100 flows into the positive electrode of the light emitting diode, then flows out from the negative electrode of the light emitting diode, and flows through the first resistor, so that the light emitting diode emits light. It can be understood that due to the unidirectional conduction characteristic of the light emitting diode, the current cannot flow from the negative electrode to the positive electrode.

[0069] The second voltage terminal 101 is electrically connected to the lighting control module 104, and the lighting control module 104 is used to control the second voltage terminal 101 to be grounded or suspended. The output line 11 has a voltage output terminal 110 and a plurality of switch circuits 12 respectively connected to the plurality of scanning lines 10. Specifically, the plurality of switch circuits 12 are respectively connected to the branch lines 103 of the plurality of scanning lines 10. More specifically, the switch circuit 12 is connected to the portion of the branch line 103 located between the light-emitting diode and the first resistor. The plurality of switch circuits 12 of the same output line 11 are connected in parallel. Each branch line 103 is correspondingly provided with a switch circuit 12. The switch circuit 12 includes a key switch, Figure 1SW1 to SW9 marked in are push switches, which correspond to the position of the key (usually located below the key). When the key is pressed, the key will move downward to trigger the key switch to close, making the switch circuit 12 conductive. Conversely, when the key switch is released, the key is reset, making the key switch disconnected.

[0070] The first voltage terminal 100 of the scan line 10 is used to pass a driving voltage signal (i.e., pass a high level or pass a high level signal or a similar expression). When the second voltage terminal 101 corresponding to the light-emitting diode (e.g., the light-emitting diode D1) is grounded and the corresponding scan line 10 (i.e., the first scan line 10a) inputs a high level driving voltage signal, the light-emitting diode is driven to emit light. The light-emitting diode can illuminate the key, thereby playing the role of keyboard backlight. Optionally, the light-emitting diode is arranged adjacent to the key switch and corresponding to the key, for example, it can be located below the key. In some embodiments, the key is at least partially transparent, for example, the part that displays the letter can be set to be transparent, so that the light-emitting diode can illuminate the corresponding letter. In some embodiments, the key can be fully transparent to present a crystal clear feeling and improve the aesthetics. In some embodiments, the key is opaque, and its inner wall is provided with a reflective surface (e.g., coated with a reflective coating), which can reflect the light of the light-emitting diode, so that the bottom of the key is illuminated, creating a sense of light around the key.

[0071] It can be understood that when the key switch (for example, SW1) is pressed and the first voltage terminal 100 of the scan line 10 (for example, the first scan line 10a) connected thereto is applied with a high-level driving voltage, the voltage output terminal 110 of the output line 11 (for example, the first output line 11a) connected to the key switch will detect a voltage signal, which is also reflected as a high level. Obviously, due to the voltage dividing effect of the light-emitting diode and the first resistor, etc., the voltage at the voltage output terminal 110 will be lower than the voltage at the first voltage terminal 100, but compared to the case where the key switch is disconnected, it is still reflected as a high level, but it is smaller than the high level of the first voltage terminal 100. Therefore, when a voltage signal whose size is within a preset range is detected at the voltage output terminal 110 of the output line 11, it indicates that there is a pressed key switch.

[0072] Theoretically, as long as the key switch is not pressed, the voltage signal at the voltage output terminal 110 is always 0. Therefore, in some embodiments, the preset range may be greater than 0V, that is, as long as a voltage of a certain magnitude is detected, it is considered that the key is pressed.

[0073] In some embodiments, in order to reduce the interference caused by the external environment and improve the accuracy of detection, the preset range can be a range greater than 0V. It is understandable that the voltage magnitude of the voltage output terminal 110 after pressing the key can be obtained by calculating the forward voltage value of the light-emitting diode, the input voltage of the first voltage terminal 110 of the scanning line and the line resistance, or it can be obtained by actual measurement. In actual implementation, even if the detected voltage value is less than the calculated voltage value or the measured voltage value, as long as it is within the allowable amplitude range, it can be considered that the key is pressed to ensure the sensitivity of the detection result. The allowable amplitude range can be used as a preset range for judging the voltage signal size. The voltage value obtained by calculation or actual measurement can be used as a basis for judging whether there is a voltage in the preset range at the voltage output terminal 110. When the voltage output terminal 110 detects a voltage signal whose voltage magnitude is within the preset amplitude value range, it indicates that a key is pressed. Optionally, when a voltage signal with a voltage magnitude greater than or equal to a fixed value is detected, it indicates that a key switch is pressed, that is, the preset range is a voltage signal with a voltage magnitude greater than or equal to a fixed value. The voltage signal may be smaller than a certain amplitude of a calculated or measured voltage value, or may be equal to a calculated or measured voltage value.

[0074] In some embodiments, when performing key detection, a high-level driving voltage is applied to the first voltage terminal 100 of each scanning line 10 in turn, and the voltage output terminal 110 of each output line 11 is detected during the period of applying the high level. When a voltage output terminal 110 detects a voltage within a preset amplitude value range, it indicates that the key switch connected between the output line 11 and the scanning line 10 applied with the high level is pressed (i.e., triggered), so that the position information of the pressed key can be obtained to achieve key detection.

[0075] For example, when a high level is applied to the first scan line 10a, if a certain voltage is detected at the voltage output terminal 110 of the first output line 11a, it indicates that the key switch SW1 is pressed, and if a certain voltage is detected at the voltage output terminal 110 of the second output line 11b, it indicates that the key switch SW2 is pressed. If a certain voltage is detected at the voltage output terminals 110 of both the first output line 11a and the second output line 11b, it indicates that the key switch SW1 and the key switch SW2 are pressed at the same time. Similarly, the position of the pressed key can be determined by combining the voltage conditions of the voltage output terminals 110 of the scan line 10 and the plurality of output lines 11 to which a high level is applied, thereby realizing key detection.

[0076] Since the light emitting diode is connected in series in the scanning line 10, the unidirectional conduction characteristic of the light emitting diode can be used to achieve the effect of anti-ghosting. For example, when the current is passed through the second scanning line 10b (i.e., the high-level driving voltage is passed through), and the key switches SW1, SW2 and SW4 are pressed at the same time, at this time, only the voltage output end of the first output line 11a can detect the voltage within the preset amplitude value range. Due to the unidirectional conduction effect of the light emitting diode D1, the current cannot pass through the first output line 11a. Figure 2 The dotted line shown flows into the second output line 11b, so that the voltage output terminal 110 of the second output line 11b detects a high level. It can be understood that when the light emitting diode is not provided, the current can flow along Figure 2 The dotted line shown flows, so that the first output line 11a and the second output line 11b both output a high level. At this time, the key switch SW5 that is not pressed may be mistakenly judged as being pressed. Therefore, the above-mentioned keyboard backlight circuit can prevent false detection.

[0077] It is understandable that, through the above circuit structure design, while achieving the light-emitting effect of the key, it can also play an anti-ghosting function, thereby simplifying the circuit structure and helping to reduce costs. At the same time, the simplified circuit structure can reduce the number of layers of the circuit board of the key output device, thereby helping to reduce the thickness of the key input device and achieve lightweight electronic equipment.

[0078] The keyboard backlight circuit includes a first chip, and the first voltage terminal 100 and the voltage output terminal 110 are both connected to the IO interface of the first chip. The first chip can input a driving voltage signal to multiple scanning lines according to a control signal, and detect the voltage signal of the voltage output terminal 110 of the output line 11, thereby realizing backlight and key detection.

[0079] In some embodiments, the lighting control module 104 includes a second chip, and the second voltage terminal 101 is connected to the IO interface of the second chip. The second chip controls the second voltage terminal 101 to be grounded or suspended. The second chip can control the corresponding second voltage terminal 101 to be grounded or suspended at a specified time according to a preset lighting effect program, thereby controlling the corresponding light-emitting diode to emit light at a specified time as needed to achieve the corresponding lighting effect.

[0080] In some embodiments, reference Figure 3 Each second voltage terminal 101 can be independently controlled to be grounded or suspended. For example, an IO interface of the second chip can be allocated to each second voltage terminal 101 to achieve a one-to-one correspondence between the second voltage terminal 101 and the IO interface of the second chip. In this way, each IO interface can independently control the lighting and closing of a light-emitting diode.

[0081] In some embodiments, reference Figure 4The second voltage terminals 101 are divided into multiple groups, and the second voltage terminals 101 included in each group can be controlled to be grounded or suspended at the same time, that is, the states of the second voltage terminals 101 in each group are the same, either all grounded or all suspended, and at least one group of second voltage terminals 101 includes at least two second voltage terminals 101, thereby saving the demand for the IO interface of the chip. For example, Figure 1 The second voltage terminals 101 of each column in the chip are taken as a group, and the second voltage terminals 101 of the column are connected to the IO interface of the same second chip. In this way, the IO interface can simultaneously control the grounding or suspension of multiple second voltage terminals 101 of the same column. It can be understood that when the second voltage terminal 101 of a certain column is grounded, which light-emitting diode of the column emits light depends on the scanning line 10 that is fed with the driving voltage signal. For example, when Figure 1 When the second voltage terminal 101 of the first column is grounded, if the first scan line 10a is passed to a high level, the light emitting diode D1 will emit light, and the other light emitting diodes will not emit light. If the first scan line 10a and the second scan line 10b are passed to a high level, the light emitting diodes D1 and D4 will emit light, and the others will not emit light. Through the combined control of the scan line 10 and the interface of the second chip, each light emitting diode can be controlled to emit light individually or simultaneously, thereby achieving a variety of lighting effects.

[0082] It should be pointed out that the first chip and the second chip can be the same chip, and the scanning line 10 driving, the output line 11 detection, and the grounding and suspension control of the second voltage terminal 101 are realized by the same chip. The first chip and the second chip can also be two different chips, one of which is used for scanning line 10 driving and output line 11 detection, and the other chip is used for grounding and suspension control of the second voltage terminal 101. For example, when the chip IO interface is sufficient, one chip can be used. When the chip pins are insufficient, two or more chips can be used. When one chip is used, since the clocks of the chips are the same, it is conducive to more accurate control.

[0083] In some embodiments, the resistance of the first resistor is 100-1000 ohms, and the driving voltage input to the first voltage terminal 100 is about 5V. By setting the resistance of the first resistor to 100-1000 ohms, the current flowing through the light-emitting diode can be 1-10mA, which meets the current required for most light-emitting diodes used in keyboards to emit light. In other embodiments, the driving voltage input to the first voltage terminal 100 is about 3.3V. At this time, the resistance of the first resistor can be selected to be 30-500 ohms so that the light-emitting diode can emit light reliably.

[0084] The resistance value of the first resistor can be adjusted according to the current and voltage parameters actually required for the normal operation of the light emitting diode, so that the light emitting diode can emit light reliably.

[0085] In some embodiments, Figure 5 As shown, the switch circuit 12 also includes a second resistor connected in series with the key switch. Figure 5 R10 to R18 are the second resistors, and the resistance of the second resistor is greater than 0.2 times of the first resistor, that is, the ratio of the resistance of the second resistor to the resistance of the first resistor is greater than 0.2, so as to ensure the reliability of the light emitting diode during the key pressing process. Figure 1 In the embodiment shown, if all the second voltage terminals 101 on a column are grounded at a certain moment, when two or more key switches on the output line 11 corresponding to the column are pressed simultaneously, the first resistors corresponding to the pressed key switches will be connected in parallel, and the resistance after the parallel connection is smaller than the resistance of the single first resistor, so that the resistance for voltage division with the light-emitting diode becomes smaller, and the current and voltage acting on the light-emitting diode will become larger. For example, referring to Figure 1 When a high level is input to the first voltage terminal 100 of the first scanning line 10a and the second voltage terminals 101 of the first column are all grounded at this time, SW1 and SW4 are pressed at the same time. When the resistance values ​​of the first resistors R1 and R4 are the same, the resistance value of the two first resistors in parallel will be only half of the original value. Therefore, the current flowing through the light-emitting diode will increase, and the voltage acting on the light-emitting diode will also increase. The more key switches are pressed at the same time, the smaller the resistance value of the voltage divided by the light-emitting diode will be. In this way, the light-emitting diode may be burned out due to excessive current flowing through the light-emitting diode, or the brightness may be too high, shortening the service life.

[0086] This problem can be solved by providing a second resistor in series with the key switch in the switch circuit 12. Figure 5 In the illustrated embodiment, when multiple keys of the same output line 10 are pressed simultaneously, due to the presence of the second resistor, the resistance of the resistor that is finally divided with the light emitting diode will decrease relatively smaller, thereby ensuring the stability of the current flowing through the light emitting diode when the key is pressed, reducing the increase in the current, which is conducive to the reliable light emission of the light emitting diode, and the light emission effect is more consistent and stable, and it is also conducive to extending its service life. For example, when the first voltage terminal 100 of the first scanning line 10a inputs a high level and the key switches SW1 and SW4 are pressed simultaneously, the first resistor R1 is connected in parallel with the resistors R10, R13, and R4. Since the resistance of the resistors R10 and R13 is greater than 0.2 times the resistance of the resistors R1 and R4, the resistance after parallel connection will be greater than the resistance after only R1 and R4 are connected in parallel, reducing the increase in the current flowing through the light emitting diode.

[0087] In order to further ensure the stability of the light emitting diode, the resistance of the second resistor can be greater than or equal to 1 times, 2 times, 3 times, 4 times, 5 times or more times the resistance of the first resistor. Optionally, the resistance of the second resistor is greater than or equal to 2 times the resistance of the first resistor, so that after pressing the switch, the total current impact is less than 33%, the change amplitude of the current flowing through the light emitting diode is smaller, and no obvious optical and electrical effects are caused on the light emitting diode, thereby effectively ensuring the stability of the light emitting diode and the reliability of use.

[0088] Optionally, the resistance of the second resistor does not exceed 10 times the resistance of the first resistor. Because the detection input of the output line is generally in a high-resistance state, when the resistance of the detection end is too large, it will affect the accuracy of the detection value. Setting the resistance of the second resistor to be 10 times less than the resistance of the first resistor is beneficial to improving the accuracy of the detection value.

[0089] Optionally, the first resistor and the second resistor may be a common resistor, a carbon ink resistor, a silver paste printed resistor, or other resistors that can be used for thin film circuits.

[0090] The color of the light emitted by the LED is not limited, for example, it can be white, red, blue or green. Optionally, the color of the light emitted by all the LEDs is the same, or the light colors of at least two LEDs are different, so as to produce a richer lighting effect. The colors of the LEDs at different positions can be set as needed.

[0091] It can be understood that by inputting a driving voltage signal to the scan line and controlling the second voltage terminals 101 to be suspended, a variety of lighting effects can be achieved. For example, when all the second voltage terminals 101 are grounded, a constantly on lighting effect can be achieved; for another example, when all the second voltage terminals 101 are suspended, no light is generated; for another example, by intermittently controlling all the second voltage terminals 101 to be suspended or grounded at the same time, a flashing lighting effect can be achieved; for another example, some of the second voltage terminals 101 can be controlled to be grounded, and the rest can be suspended, so as to produce lighting effects such as patterns or texts; for another example, the second voltage terminals 101 can be controlled to be grounded in columns or rows, so as to achieve a lighting effect that gradually lights up in a certain order. Of course, the above are only examples, and more diverse lighting effects can be achieved according to needs. Optionally, the change of lighting effects can be modified or selected by the user.

[0092] It should be noted that when the key switch corresponding to the energized scan line 10 is pressed, the light-emitting diode on the scan line 10 will also emit light. For example, when the first scan line 10a is passed to a high level, the key switch SW1 is pressed at this time, and the light-emitting diode D1 will emit light. In this case, if the light-emitting diode is only used to illuminate the key itself or the letters on the key, then because the finger will cover the key when the key is pressed, even if the key or the letters on the key are illuminated, it will not be noticed, and will not affect the overall lighting effect display. If the light-emitting diode is used to illuminate the surrounding area of ​​the key, then the lighting effect of emitting light when the key is pressed can be achieved. For example, all the second voltage terminals 101 are suspended, and each time a key is pressed, a bright light will be emitted around the corresponding key, thereby achieving a lighting effect of emitting light when pressed. It can be understood that whether the light-emitting diode is used to illuminate the key, the letter or the area around the key, it does not affect the lighting effect display of the keyboard when the key is not in use.

[0093] Next, a method for backlight driving using the keyboard backlight circuit described above is introduced.

[0094] The keyboard backlight circuit driving method comprises the following steps:

[0095] S1. A high level (i.e., a driving voltage signal) of a preset duration is sequentially applied to the first voltage terminals 100 of multiple scanning lines 10, and a high level is only applied to the first voltage terminal 100 of one scanning line 10 at the same time, that is, a high level is applied to at most one scanning line 10 at the same time, and the second voltage terminal 101 corresponding to the light-emitting diode that needs to emit light is grounded according to the preset light-emitting sequence and light-emitting time, and the second voltage terminal 101 corresponding to the light-emitting diode that does not need to emit light is controlled to be suspended.

[0096] It should be noted that in step S1, the high level of the preset duration is sequentially applied to the first voltage terminals 100 of the plurality of scan lines 10, and it is not necessary to apply the high level to the plurality of scan lines 10 in the same order. Figure 6 , the total time from the first scan line 10 being passed to the high level to the last scan line 10 being passed to the high level is a scan cycle T1, then it is only necessary to pass the high level to all scan lines 10 within a scan cycle T1, and it is not necessary to follow a certain order. For example, the first scan cycle T1 can pass the high level to the first scan line 10a, the second scan line 10b and the third scan line 10c in turn, and the second scan cycle can pass the high level to the first scan line 10a, the third scan line 10c and the second scan line 10b in turn. Of course, in order to simplify the program, it is optional that each scan cycle T1 always passes the high level to each scan line in the same order, for example Figure 6 In the embodiment, a high level is applied to the first scan line 10a, the second scan line 10b and the third scan line 10c in sequence.

[0097] In step S1, the preset light-emitting sequence and light-emitting time can be recorded in the built-in light-emitting program. For example, the light-emitting diodes D1 to D9 can be controlled to light up in sequence, or the light-emitting diodes can be controlled to light up in sequence in columns, or the light-emitting diodes at predetermined positions can be controlled to light up at the same time, so as to display patterns or patterns or texts, etc. It can be understood that the scanning cycle T1 is very short. In a short time, all the scanning lines 10 will be passed to a high level at least once. Therefore, no matter which light-emitting diode on which scanning line 10 needs to emit light, it can emit light to achieve the lighting effect.

[0098] In order to realize key detection, the keyboard backlight circuit driving method also includes the following steps:

[0099] S2. Detect the voltage signals of the voltage output terminals 110 of the multiple output lines 11 during the time period when the high level is applied, and determine whether there is a voltage signal whose voltage magnitude is within the preset amplitude value range, that is, determine whether the voltage magnitude of the detected voltage signal is within the preset amplitude value range.

[0100] S3. When it is detected that the voltage signal of a certain voltage output terminal 110 is within the preset amplitude value range, the triggered key switch is determined in combination with the voltage conditions of the voltage output terminal 110 of the high-level scanning line 10 and the multiple output lines 11.

[0101] It can be understood that the scanning period T1 is short enough that all the scanning lines 10 can be passed to a high level at least once within the extremely short scanning period, and the output voltages of all the output lines 11 are detected when any scanning line 10 inputs a high level, so that under normal operation, no matter when a key is pressed by hand, it can be detected that the key is pressed.

[0102] Furthermore, in order to ensure that the light-emitting diode can continuously emit light, the time of the scanning cycle T1 is set so that the naked eye cannot recognize the flickering of the light-emitting diode. It can be understood that even if all the second voltage terminals 101 are grounded, when a high level is input to a certain scanning line 10, the light-emitting diode on the scanning line 10 will emit light, while other light-emitting diodes will not emit light. Therefore, the light-emitting diode does not emit light continuously, but emits light intermittently as the energized scanning line 10 changes. When the intermittent time is short enough, the flickering of the light-emitting diode will not be detected by the naked eye, thereby ensuring that the light-emitting diode can be displayed as always on in external performance.

[0103] Optionally, the interval time of the light emitting diode that needs to be displayed as always on is not greater than 41.6ms, so that the human eye sees it as always on and cannot recognize flickering.

[0104] Optionally, the scanning cycle T1 is no longer than 41.6 ms, which helps the light emitting diode to emit continuous light to the senses and ensures that under normal operation, it can be detected that the key is pressed no matter when the key is pressed by hand.

[0105] In step S2, during the time period when each scanning line 10 is at a high level, voltage detection is performed on the voltage output terminals 110 of all output lines 11 to ensure that no key is missed in the detection.

[0106] In order to allow enough time to detect the voltage of the output line 11 after the scan line 10 is powered on, in the step S1, the time for any of the scan lines 10 to input a high level each time is not less than 50 microseconds, so that there is enough time to detect the output line 11. Further, optionally, the time for any of the scan lines 10 to input a high level each time is not less than 100 microseconds. As a further improvement, in the step S2, the voltage output terminal 110 of the output line 11 is detected after a preset time period after the scan line 10 is fed with a high level. Generally, within a period of time after the scan line 10 is fed with a high level, the level will jitter (lasting about 10 to 30 microseconds). Therefore, the voltage output terminal 110 is detected after a preset time period after the scan line 10 is fed with a high level, which can make the voltage more stable and the detection result more accurate. Optionally, the length of the preset time period is greater than or equal to 30 microseconds, and can be further selected to be greater than or equal to 50 microseconds, so as to ensure the accuracy of the detection result and avoid false detection caused by level jitter.

[0107] Optionally, in step S3, judging the triggered key switch by combining the voltage conditions of the voltage output terminals 110 of the scan lines 10 and the plurality of output lines 11 which are connected to a high level comprises the following steps:

[0108] S31. When it is detected that the voltage signal of the voltage output terminal 110 of a certain output line 11 is within the preset amplitude value range, the scanning line 10 that is passed through the high level at the same time is obtained. For the convenience of description, the output line 11 corresponding to the voltage output terminal 110 whose voltage signal is within the preset amplitude value range is called the output line 11 that meets the requirements;

[0109] S32. Identify the key switch connected between the output line 11 that meets the requirements and the scan line 10 that is at a high level at the same time. The key switch is the triggered key switch.

[0110] It can be understood that the position information of each key switch corresponding to the scan line 10 and the output line 11 has been recorded and stored in advance. Therefore, when it is known that the output line 11 that detects the voltage and the scan line 10 that passes the high level at the same time are detected, the position information of the key switch can be obtained, thereby identifying which key switch is triggered. The position information of the key switch corresponds to the position of the pressed key.

[0111] It is understandable that although the intermittent lighting time of the LED is short enough and the frequency is fast enough to appear to be continuously emitting light, the actual lighting time of the LED is shorter over a period of time. For example, in the case of three scanning lines 10, the LED only emits light for one-third of the time, which will cause the actual observed light brightness to be lower than the light brightness observed when the LED is continuously powered on.

[0112] In order to solve the above-mentioned problem of low brightness, another keyboard backlight circuit driving method is introduced next. For the convenience of description, the above keyboard backlight circuit driving method is called the first keyboard backlight circuit driving method, and the one introduced next is called the second keyboard backlight circuit driving method.

[0113] refer to Figure 7 The second keyboard backlight circuit driving method comprises the following steps:

[0114] A1. Drive the light emitting diode to emit light as needed within the first time period t10.

[0115] A2. In the second time period t11, key detection is performed.

[0116] A3. Repeat steps A1 and A2 in sequence.

[0117] In the second keyboard backlight circuit driving method, all light-emitting diodes first emit light as needed in the first time period t10, for example, they can be always on, or form a breathing or flashing or text, pattern display and other lighting effects, and then perform key detection in the second time period t11. At the same time, in the first time period t10, there is no need to energize each scanning line 10 in turn in a scanning manner, and the light-emitting diodes can continue to emit light for a longer time, so that the brightness appears higher. For example, in the case where the light-emitting diodes continue to emit light, in the same time period (a time period greater than the sum of the first time period t10 and the second time period t11), the power-on and light-emitting time of the light-emitting diodes in the second keyboard backlight circuit driving method is longer than the power-on and light-emitting time of the light-emitting diodes in the first keyboard backlight circuit driving method, so that the light brightness observed by the human eye is higher, which is conducive to further improving the display effect and aesthetics. When the light-emitting diodes are used to illuminate the letters on the keys, they can be more easily identified.

[0118] In the step A1, within the first time period t10, the second voltage terminal 101 corresponding to the light-emitting diode that needs to emit light is grounded according to the preset light-emitting sequence and light-emitting time, and at the same time, the driving voltage is applied to the first voltage terminal 100 corresponding to the light-emitting diode that needs to emit light, and the second voltage terminal 101 corresponding to the light-emitting diode that does not need to emit light is controlled to be suspended, so that the light-emitting diode that needs to emit light emits light according to the preset light-emitting sequence and light-emitting time. For example, a high level is applied to all scan lines 10 at the same time, and then the second voltage terminal 101 of each column is grounded from left to right in turn, and each grounding time is 1s, so that the light-emitting diodes can emit light from left to right in columns, and each column emits light for 1s. It can be understood that the preset light-emitting sequence and light-emitting time can be built into the program.

[0119] The first time period t10 and the second time period t11 form a light-emitting cycle. It can be understood that the longer the first time period t10 is, when the light-emitting diode continues to emit light in this time period, the longer the light-emitting diode can be powered on to continuously emit light, and the brighter the brightness recognized by the naked eye. When the light-emitting diode produces a light effect in this time period, the recognition of the light emission of the second time period t11 by the human eye can be reduced, and the continuity of the light effect change can be better guaranteed. Optionally, the first time period t10 is greater than the second time period t11, so that the light-emitting diode can emit light with good brightness and improve the continuity of the light effect change. Further optionally, the time ratio of the first time period t10 to the light-emitting cycle T2 is not less than 80%, so that the brightness perceived by the naked eye is basically consistent with the brightness achieved by the light-emitting diode when it is always powered on, and the continuity of the light effect change is better. The time ratio of the first time period t10 to the light-emitting cycle T2 can be further selected to be not less than 90%. Further optionally, the time ratio of the first time period t10 to the light-emitting cycle T2 is not greater than 99.9%, so as to prevent the key detection time from being too short, resulting in inaccurate detection.

[0120] It can be understood that the light-emitting period T2 needs to be short enough. Within the extremely short light-emitting period T2, all scan lines 10 can be passed to a high level at least once, and the output voltages of all output lines 11 are detected when any scan line 10 is passed to a high level, so that under normal operation, no matter when a person presses the key, it can be detected that the key is pressed.

[0121] Optionally, the duration of the light-emitting cycle T2 is no greater than (or less than or equal to, no greater than) 41.6 ms, which is conducive to making the light-emitting diode emit continuous light in a sensory sense and ensuring that under normal operation, no matter when the key is pressed by a person's hand, it can be detected that the key is pressed.

[0122] In some embodiments, the key detection step in step A2 includes:

[0123] A21. A high level of a preset duration is applied to the first voltage terminals 100 of the plurality of scan lines 10 in sequence, and a high level is applied to only one scan line 10 at a time, that is, a high level is applied to at most one scan line 10 at a time.

[0124] A22. Detect the voltage signals of the voltage output terminals 110 of the plurality of output lines 11 during the period of time when the high level is applied, and determine whether there is a voltage signal whose voltage is within a preset amplitude range.

[0125] A23. When it is detected that the voltage signal of a certain voltage output terminal 110 is within the preset amplitude value range, the triggered key switch is determined in combination with the voltage conditions of the voltage output terminal 110 of the high-level scanning line 10 and multiple output lines 11.

[0126] It can be understood that the key detection step in step A2 is basically the same as the step in the first keyboard backlight circuit driving method, and reference may be made to the relevant content in the first keyboard backlight circuit driving method above.

[0127] The total time from the first scanning line 10 being passed to the high level to the last scanning line 10 being passed to the high level is a scanning cycle T3. It can be understood that in the second keyboard backlight circuit driving method, the length of the second time period t11 is consistent with the time period of the scanning cycle T3. Of course, it can also be inconsistent, for example, refer to Figure 8 , there may be a pause before and / or after the scanning cycle T3, so that the second time period t11 is greater than the scanning cycle T3. In addition, the second time period t11 is not limited to only one scanning cycle T3, and it may include more scanning cycles to perform more comprehensive detection and improve the accuracy of detection. Obviously, setting the second time period t11 and the time periods of N (N is an integer greater than or equal to 1) scanning cycles T3 to have the same time length can make more full use of time and improve work efficiency.

[0128] Likewise, the duration of the scanning cycle T3 may be no greater than 41.6 ms.

[0129] Similarly, in step A21, the time for any of the scan lines 10 to input a high level each time is not shorter than 50 microseconds, and can be further selected to be not shorter than 100 microseconds. In step A22, the voltage output terminal 110 of the output line 11 is detected after a preset time period after the scan line 10 is passed through a high level, so that the voltage of the voltage output terminal 110 is more stable and the detection result is more accurate. Optionally, the length of the preset time period is greater than or equal to 30 microseconds, and can be further selected to be greater than or equal to 50 microseconds, so as to ensure the accuracy of the detection result and avoid false detection caused by level jitter.

[0130] Similarly, in step A23, judging the triggered key switch by combining the voltage conditions of the voltage output terminals 110 of the scan lines 10 and the multiple output lines 11 with high levels may include the following steps:

[0131] A231. When the voltage signal of the voltage output terminal 110 of a certain output line 11 is detected to be within the preset amplitude value range, the scanning line 10 which is passed to the high level at the same time is obtained;

[0132] A232. Identify the key switch connected between the output line 11 detected to meet the requirements and the scanning line 10 that is passed to a high level at the same time. The key switch is the triggered key switch. The output line 11 that meets the requirements refers to the output line 11 corresponding to the voltage output terminal 110 whose detected voltage signal is within the preset amplitude value range.

[0133] Optionally, in order to allow human eyes to recognize the always-on light, the duration of the second time period t11 is less than or equal to 41.6 ms, so that during key detection, human eyes cannot recognize the flashing of the light emitting diode.

[0134] Further optionally, the duration of the light-emitting cycle T2 is not greater than (or less than or equal to, not exceeding) 41.6ms, so that the duration of the light-emitting cycle T2 is short enough to reliably identify the normal key operation of a person's hand. Optionally, the duration of the second time period t11 is less than or equal to 15ms to further improve the continuity of the light of the light-emitting diode recognized by the human eye, so that the human eye observes a light-emitting diode that is basically always on.

[0135] Optionally, when key detection is performed in step A2, all second ground terminals 101 are suspended or grounded, or the second ground terminals 101 are suspended or grounded according to required lighting effects.

[0136] The present invention also proposes a third keyboard backlight circuit driving method, which comprises the following steps:

[0137] B1. In the first preset time period, the light-emitting diodes that need to emit light are controlled to emit light according to the preset light-emitting time and light-emitting sequence, and only one scan line 10 is passed to a high level at the same time;

[0138] B2. While the light-emitting diode is emitting light, the voltage signal of the voltage output terminal 110 of the corresponding output line 11 is detected to determine whether the key switch corresponding to the light-emitting diode is pressed;

[0139] B3. Determine whether all light emitting diodes have emitted light within the first preset time period. If so, repeat steps B1 to B3; if not, execute step B4;

[0140] B4. Perform key detection and then repeat steps B1 to B3.

[0141] In the third keyboard backlight circuit driving method, while the lighting effect is being displayed, the key detection is performed on the circuit with the lights on. If all the lights have been lit within the first preset time period, it means that all the keys have been key-detected, so there is no need to arrange a special time for key detection, the lighting effect can be continued, and the continuity of the lighting effect change is better. On the contrary, if there is an LED that has not been lit within the first preset time period, it means that the key corresponding to the LED has not been detected within this period, so a special key detection is required to avoid missed detection.

[0142] Optionally, in step B1, the second voltage terminal 101 corresponding to the light-emitting diode that needs to emit light is controlled to be grounded, and at the same time a high level is passed to the first voltage terminal 100 corresponding to the light-emitting diode that needs to emit light, so that the light-emitting diode that needs to emit light is illuminated. It can be understood that other light-emitting diodes do not emit light. For example, the second voltage terminal 101 corresponding to the light-emitting diode that does not need to emit light can be controlled to be suspended to prevent it from emitting light (without considering the situation where the light-emitting diode emits light after a button is pressed).

[0143] In step B2, whether the key switch corresponding to the light-emitting diode is pressed is determined by judging whether the voltage is within the preset amplitude value range. When it is detected that the voltage signal at the voltage output terminal 110 is within the preset amplitude value range, it indicates that the corresponding key switch is pressed.

[0144] In order to ensure the accuracy of key detection, the first preset time period is relatively short to prevent key detection from being missed in a longer time period because a key has not been detected. Optionally, the time for key detection is no more than 15ms, and the total time of the first preset time period and key detection is no more than 41.6ms. In this way, the total time is relatively short, and normal key operation by human hands can be reliably identified.

[0145] In step B3, it is determined whether all the light emitting diodes have emitted light in the first preset time period. This can be determined based on the power-on status of the scan line 10 and the grounding status of the second voltage terminal 101 in the first preset time period. When a certain scan line 10 is connected to a high level and a certain second voltage terminal 101 of the scan line 10 is grounded, it indicates that the light emitting diode corresponding to the grounded second voltage terminal 101 has emitted light. By identifying the light emitting diodes that have emitted light in the first preset time period, it is possible to determine whether all the light emitting diodes have emitted light in the first preset time period, and it is also possible to determine which light emitting diodes have not emitted light.

[0146] Optionally, in step B3, determining whether all light emitting diodes have emitted light within the first preset time period includes the following steps:

[0147] Step B30. Determine whether all the scan lines 10 are passed through the high level within the first preset time period. If not, it indicates that not all the light-emitting diodes have emitted light, and step B4 can be executed. If yes, step B31 is executed;

[0148] Step B31. Determine whether all the second voltage terminals 101 of all the scan lines 10 that are passed through the high level are grounded when the high level is passed through. If not, it indicates that not all the light-emitting diodes have emitted light, and step B4 can be executed. If so, it indicates that all the light-emitting diodes have emitted light, and steps B1 to B3 can be executed.

[0149] In step B2, the voltage signal of the voltage output terminal 110 of the output line 11 corresponding to the light-emitting diode is detected to determine whether the corresponding key switch is pressed. The corresponding key switch is the key switch on the switch circuit 12 connecting the output line 11 and the branch line 103 where the light-emitting diode is located.

[0150] In step B4, the key detection may refer to the key detection step above, for example, referring to step A2 above, step B4 includes:

[0151] B41. A high level of a preset duration is applied to the first voltage terminals 100 of the plurality of scan lines 10 in sequence, and a high level is applied to only one scan line 10 at a time, that is, a high level is applied to at most one scan line 10 at a time.

[0152] B42. Detect the voltage signals of the voltage output terminals 110 of the plurality of output lines 11 during the period of time when the high level is applied, and determine whether there is a voltage signal whose voltage magnitude is within a preset amplitude value range.

[0153] B43. When it is detected that the voltage signal of a certain voltage output terminal 110 is within the preset amplitude value range, the triggered key switch is determined in combination with the voltage conditions of the voltage output terminal 110 of the high-level scanning line 10 and multiple output lines 11.

[0154] In step B43, judging the triggered key switch by combining the voltage conditions of the voltage output terminals 110 of the scan lines 10 and the plurality of output lines 11 which are connected to a high level includes the following steps:

[0155] B431. When the voltage signal of the voltage output terminal 110 of a certain output line 11 is detected to be within the preset amplitude value range, the scanning line 10 which is passed to the high level at the same time is obtained;

[0156] B432. Identify the push switch connected between the detected output line 11 that meets the requirements and the scanning line 10 that is passed to a high level at the same time. The push switch is the triggered push switch. The output line 11 that meets the requirements refers to the output line 11 corresponding to the voltage output terminal 110 whose detected voltage signal is within the preset amplitude value range.

[0157] The present invention further provides a key input device, which includes any one of the keyboard backlight circuits described above. The key input device may be, for example, a keyboard, such as a keyboard of a mobile phone or a computer.

[0158] The present invention also provides an electronic device, which includes any of the keyboard backlight circuits described above or includes any of the key input devices described above. The electronic device may be, for example, a mobile phone with keys, a laptop computer, a desktop computer, a game console or other devices with keys.

[0159] The present invention also proposes a processor-readable storage medium, which is used to store processor-executable instructions. When the processor-executable instructions are loaded and executed by the processor, any of the keyboard backlight circuit driving methods described above can be implemented. It can be understood that the key input device and / or electronic device can include the processor-readable storage medium.

[0160] 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.

[0161] The above are only specific embodiments 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 with integrated key detection function, characterized in that: include: A plurality of scanning lines (10), wherein the plurality of scanning lines (10) are arranged at intervals, wherein the scanning lines (10) have a main line (102) and a plurality of branch lines (103) connected in parallel to the main line (102), wherein the main line (102) has a first voltage end (100), and the branch line (103) has a second voltage end (101), and a light-emitting diode and a first resistor connected in series are sequentially arranged between a connection position between the branch line (103) and the main line (102) and the second voltage end (101), wherein the light-emitting diode is used to realize keyboard backlighting and enables current to be unidirectionally conducted toward the first resistor, and the second voltage end (101) is electrically connected to a lighting control module (104), and the lighting control module (104) is used to control the second voltage end (101) to be grounded or suspended; and, A plurality of output lines (11), the plurality of output lines (11) are arranged at intervals and are arranged in an alternating manner with the scanning lines (10) to form a matrix circuit, the output lines (11) having a voltage output terminal (110) and a plurality of switch circuits (12) respectively connected to the branch lines (103) of the plurality of scanning lines (10), each branch line (103) being provided with a corresponding switch circuit (12), the switch circuit (12) being connected to a portion of the branch line (103) located between the light emitting diode and the first resistor, and the switch circuit (12) comprising a key switch.

2. The keyboard backlight circuit with integrated key detection function as claimed in claim 1, characterized in that: The first voltage end (100) and the voltage output end (110) are both connected to the IO interface of the first chip, the first chip inputs a high level to the plurality of scanning lines (10), and detects the voltage signal of the voltage output end (110) of the output line (11); The lighting control module (104) comprises a second chip, the second voltage terminal (101) is connected to an IO interface of the second chip, the second voltage terminal (101) is controlled by the second chip to be grounded or suspended, and the first chip and the second chip are the same chip or two different chips.

3. The keyboard backlight circuit with integrated key detection function as claimed in claim 1, characterized in that: The switch circuit (12) also includes a second resistor connected in series with the key switch.

4. The keyboard backlight circuit with integrated key detection function as claimed in claim 1, characterized in that: Each of the second voltage terminals (101) can be independently controlled to be grounded or suspended; or, The second voltage terminals (101) are divided into a plurality of groups, and the second voltage terminals (101) of each group can be controlled to be grounded or suspended at the same time, and at least one group includes at least two second voltage terminals (101).

5. A keyboard backlight circuit driving method, characterized in that: The method is implemented by the keyboard backlight circuit with integrated key detection function as claimed in any one of claims 1 to 4, and the keyboard backlight circuit driving method comprises the following steps: S1. sequentially passing a high level of a preset duration to the first voltage ends (100) of the plurality of scanning lines (10), and passing a high level to only one first voltage end (100) of the scanning line (10) at a time, and controlling the second voltage ends (101) corresponding to the light-emitting diodes that need to emit light to be grounded according to a preset light-emitting sequence and light-emitting time, and controlling the second voltage ends (101) corresponding to the light-emitting diodes that do not need to emit light to be suspended.

6. The keyboard backlight circuit driving method according to claim 5, characterized in that: It also includes the following steps: S2. Detecting the voltage signal of the voltage output terminal (110) of all the output lines (11) during the period of high level, and determining whether the voltage is within a preset amplitude range; S3. When it is detected that the magnitude of the voltage signal of a certain voltage output terminal (110) is within a preset amplitude value range, the triggered key switch is determined by combining the voltage conditions of the voltage output terminals (110) of the scanning line (10) passing a high level and the plurality of output lines (11); In the step S3, judging the triggered key switch by combining the voltage conditions of the voltage output ends (110) of the scan line (10) with a high level and the plurality of output lines (11) comprises the following steps: S31. Get the scan line (10) with high level at the same time; S32. Identify a key switch connected between an output line (11) that meets the requirements and a scan line (10) that is simultaneously supplied with a high level, the key switch being the triggered key switch, and the output line (11) that meets the requirements refers to the output line (11) corresponding to the voltage output terminal (110) whose detected voltage signal is within a preset amplitude value range.

7. A keyboard backlight circuit driving method, characterized in that: The method is implemented by the keyboard backlight circuit with integrated key detection function as claimed in any one of claims 1 to 4, and the keyboard backlight circuit driving method comprises the following steps: A1. Driving the light emitting diode to emit light as needed in the first time period t10; A2. Perform key detection in the second time period t11; A3. Repeat steps A1 and A2 in sequence.

8. The keyboard backlight circuit driving method according to claim 7, characterized in that: In the step A1, within the first time period t10, the second voltage terminal (101) corresponding to the light-emitting diode that needs to emit light is controlled to be grounded according to a preset light-emitting sequence and light-emitting time, and at the same time, a high level is passed to the first voltage terminal (100) corresponding to the light-emitting diode that needs to emit light, and the second voltage terminal (101) corresponding to the light-emitting diode that does not need to emit light is controlled to be suspended.

9. The keyboard backlight circuit driving method according to claim 8, characterized in that: The step A2 comprises the following steps: A21. sequentially passing a high level for a preset time length to the first voltage ends (100) of the plurality of scanning lines (10), and passing a high level to only the first voltage end (100) of one scanning line (10) at the same time; A22. Detecting the voltage signals of the voltage output terminals (110) of the plurality of output lines (11) during the period of time when the high level is applied, and determining whether there is a voltage signal whose voltage magnitude is within a preset amplitude value range; A23. When the magnitude of the voltage signal of a certain voltage output terminal (110) is detected to be within a preset amplitude value range, the voltage condition of the voltage output terminal (110) of the voltage output line (10) and the plurality of output lines (11) connected to a high level is combined to determine the triggered key switch; In the step A23, the triggered key switch is determined by combining the voltage conditions of the voltage output terminals (110) of the scanning lines (10) and the plurality of output lines (11) that are connected to a high level as follows: A231. When the voltage signal of the voltage output terminal (110) of a certain output line (11) is detected to be within a preset amplitude value range, a scanning line (10) having a high level at the same time is obtained; A232. Identify a key switch connected between an output line (11) that meets the requirements and a scanning line (10) that is simultaneously supplied with a high level. The key switch is the triggered key switch. The output line (11) that meets the requirements refers to the output line (11) corresponding to the voltage output terminal (110) whose detected voltage signal is within a preset amplitude range.

10. A keyboard backlight circuit driving method, characterized in that: The method is implemented by the keyboard backlight circuit with integrated key detection function as claimed in any one of claims 1 to 4, and the keyboard backlight circuit driving method comprises the following steps: B1. In the first preset time period, the light-emitting diodes that need to emit light are controlled to emit light according to the preset light-emitting time and light-emitting sequence, and only one scan line (10) is passed to a high level at the same time; B2. While the light-emitting diode is emitting light, the voltage signal of the voltage output terminal (110) of the corresponding output line (11) is detected to determine whether the key switch corresponding to the light-emitting diode is pressed; B3. Determine whether all light emitting diodes have emitted light within the first preset time period. If so, repeat steps B1 to B3; if not, execute step B4; B4. Perform key detection and then repeat steps B1 to B3.

11. The keyboard backlight circuit driving method according to claim 10, characterized in that: In the step B1, the second voltage terminal (101) corresponding to the light-emitting diode that needs to emit light is controlled to be grounded, and at the same time, a high level is passed to the first voltage terminal (100) corresponding to the light-emitting diode that needs to emit light, so that the light-emitting diode that needs to emit light emits light; In the step B2, whether the key switch corresponding to the light-emitting diode is pressed is determined by judging whether the voltage is within the preset amplitude value range. When it is detected that the voltage signal at the voltage output terminal (110) is within the preset amplitude value range, it indicates that the corresponding key switch is pressed.

12. The keyboard backlight circuit driving method according to claim 10, characterized in that: In step B3, determining whether all light emitting diodes have emitted light within the first preset time period includes the following steps: Step B30. Determine whether all the scan lines (10) are passed through an over-high level within the first preset time period. If not, it indicates that not all light-emitting diodes have emitted light. If so, proceed to step B31. Step B31. Determine whether all the second voltage terminals (101) of the scan lines (10) that are passed through a high level are grounded when a high level is passed through. If not, it indicates that not all light emitting diodes have emitted light. If so, it indicates that all light emitting diodes have emitted light.

13. The keyboard backlight circuit driving method according to claim 10, characterized in that: In step B4, key detection includes the following steps: B41. sequentially passing a high level of a preset duration to the first voltage ends (100) of the plurality of scanning lines (10), and passing a high level to only the first voltage end (100) of one scanning line (10) at the same time; B42. Detecting the voltage signals of the voltage output terminals (110) of the plurality of output lines (11) during the period of time when the high level is applied, and determining whether there is a voltage signal whose voltage magnitude is within a preset amplitude value range; B43. When the magnitude of the voltage signal of a voltage output terminal (110) is detected to be within a preset amplitude value range, the voltage of the voltage output terminal (110) of the high-level scan line (10) and the plurality of output lines (11) is combined to determine the triggered key switch; In the step B43, judging the triggered key switch by combining the voltage conditions of the voltage output terminals (110) of the scanning lines (10) and the plurality of output lines (11) which are connected to a high level comprises the following steps: B431. When the voltage signal of the voltage output terminal (110) of a certain output line (11) is detected to be within a preset amplitude value range, a scanning line (10) having a high level at the same time is obtained; B432. Identify the key switch connected between the output line (11) that meets the requirements and the scanning line (10) that is simultaneously supplied with a high level. The key switch is the triggered key switch. The output line (11) that meets the requirements refers to the output line (11) corresponding to the voltage output terminal (110) whose detected voltage signal is within a preset amplitude value range.

Images