CN114071826A

CN114071826A - LED dimming circuit, chip, wearable device and dimming method

Info

Publication number: CN114071826A
Application number: CN202111438377.1A
Authority: CN
Inventors: 何晨光; 庞盼; 刘欢; 周百柯; 秦晨钟
Original assignee: Chipsea Technologies Shenzhen Co Ltd
Current assignee: Chipsea Technologies Shenzhen Co Ltd
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2022-02-18
Anticipated expiration: 2041-11-29

Abstract

The invention provides an LED dimming circuit, a chip, wearable equipment and a dimming method, and aims to solve the technical problem of low LED dimming efficiency in the prior art. The LED dimming circuit, the chip, the wearable device and the dimming method receive the first optical digital code value, compare the first optical digital code value with a preset target threshold range, determine whether a dimming control signal of the LED driving circuit and dimming information when the dimming control signal needs to be adjusted according to a comparison result, adjust the current dimming control signal according to the dimming information, and send the adjusted dimming control signal to the LED driving circuit; by the mode, the intensity of the light signal obtained by superposing the light emitted by the LED and the ambient light is controlled within the detection range corresponding to the target threshold range, so that the self-adaptive adjustment of the dimming control signal is realized, and the LED dimming efficiency is improved.

Description

LED dimming circuit, chip, wearable device and dimming method

[ technical field ] A method for producing a semiconductor device

The invention relates to the technical field of electronic equipment, in particular to an LED dimming circuit, a chip, wearable equipment and a dimming method.

Background

Currently, the wearable device mainly measures the heart rate and the blood oxygen saturation by extracting heart rate characteristics and blood oxygen saturation characteristics from a PPG (PhotoPlethysmoGraphy) signal, and further calculating the heart rate and the blood oxygen saturation according to the extracted heart rate characteristics and blood oxygen saturation characteristics. The principle of the PPG signal for measuring heart rate and blood oxygen saturation is that monochromatic LED (Light-emitting diode) Light is emitted to the skin, the LED reflected Light reflected back through the skin tissue is received by the photosensor and converted into an electrical signal, and the electrical signal is converted into a digital signal by the analog-to-digital converter, and further calculated according to the digital signal.

Most of the prior art is the mode that utilizes fixed size emission current drive LED to produce LED light, and LED reflected light signal that LED light shines skin tissue reflection back has probably appeared surpassing receiving circuit's detectable scope, leads to LED reflected light signal can't be detected, and when above-mentioned condition appeared, can only rely on manual dimming mode to adjust emission current, generally need adjust many times repeatedly, adjust the back inspection result at every turn, resume the regulation, adjust inefficiency, the flexibility is relatively poor.

Disclosure of Invention

The invention aims to provide an LED dimming circuit, a chip wearable device and a dimming method, and aims to solve the technical problem of low LED dimming efficiency in the prior art.

The technical scheme of the invention is as follows: the LED dimming circuit comprises a processing and judging module and a dimming control module;

the processing and judging module is used for receiving a first optical digital code value in a dimming state, comparing the first optical digital code value with a preset target threshold range to obtain a first comparison result, and outputting dimming information according to the first comparison result, wherein the first optical digital code value is a digital signal obtained by receiving and performing analog-to-digital conversion on an optical signal emitted by an LED and an ambient optical signal;

the dimming control module is used for receiving the dimming information output by the processing and judging module and acquiring a current dimming control signal;

and adjusting the current dimming control signal according to the dimming information, updating the current dimming control signal according to the adjusted dimming control signal, and outputting the updated current dimming control signal to the LED driving circuit.

The other technical scheme of the invention is as follows: a chip is provided, and the chip comprises the LED dimming circuit.

The other technical scheme of the invention is as follows: a wearable device is provided, and the wearable device comprises the LED dimming circuit.

The other technical scheme of the invention is as follows: provided is an LED dimming method, comprising:

in a dimming state, comparing an acquired first optical digital code value with a preset target threshold range to obtain a first comparison result, wherein the first optical digital code value is a digital signal obtained by receiving and performing analog-to-digital conversion on an optical signal emitted by an LED and an ambient optical signal;

obtaining dimming information according to the first comparison result, and adjusting the current dimming control signal according to the dimming information;

and updating the current dimming control signal according to the adjusted dimming control signal, and outputting the updated current dimming control signal to the LED driving circuit.

The LED dimming circuit, the chip, the wearable device and the dimming method receive the first optical digital code value, compare the first optical digital code value with a preset target threshold range, determine whether a dimming control signal of the LED driving circuit and dimming information when the dimming control signal needs to be adjusted according to a comparison result, adjust the current dimming control signal according to the dimming information, and send the adjusted dimming control signal to the LED driving circuit; by the mode, the intensity of the light signal obtained by superposing the light emitted by the LED and the ambient light is controlled within the detection range corresponding to the target threshold range, so that the self-adaptive adjustment of the dimming control signal is realized, and the LED dimming efficiency is improved.

Drawings

Fig. 1 is a schematic diagram illustrating an application environment of an LED dimming circuit according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an LED dimming circuit according to a first embodiment of the present invention;

FIG. 3 is a schematic diagram of an LED dimming circuit according to a first embodiment of the present invention;

fig. 4 is a schematic structural diagram of another LED dimming circuit according to the first embodiment of the present invention;

FIG. 5 is a flowchart illustrating a method for dimming an LED according to a second embodiment of the present invention;

fig. 6 is a schematic structural diagram of an LED dimming device according to a third embodiment of the present invention;

fig. 7 is a flowchart illustrating an LED dimming method according to a fourth embodiment of the present invention;

fig. 8 is a flowchart illustrating an LED dimming method according to a fifth embodiment of the present invention;

fig. 9 is a flowchart illustrating an LED dimming method according to a sixth embodiment of the present invention;

FIG. 10 is a diagram illustrating a chip structure according to a seventh embodiment of the present invention;

fig. 11 is a schematic structural diagram of a wearable device according to an eighth embodiment of the present invention;

fig. 12 is a schematic structural diagram of a wearable device according to a ninth embodiment of the present invention;

fig. 13 is a schematic structural diagram of a wearable device according to a tenth embodiment of the present invention;

fig. 14 is a schematic structural diagram of a storage medium according to an eleventh embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The LED dimming circuit 100 provided by the present invention can be applied to a wearable device 200 shown in fig. 1, wherein the wearable device 200 includes a transmitting circuit 21 and a receiving circuit 22, wherein the transmitting circuit 21 includes an LED and an LED driving circuit 211 for driving the LED to emit light according to a preset dimming control signal; the LED light is emitted to the skin and reflected by the skin tissue to form LED reflected light; the receiving circuit 22 includes a photodiode 221, a transimpedance amplifier 222, a programmable gain amplifier 223, a filter circuit 224, an analog-to-digital converter 225 and the LED dimming circuit 100, which are connected in sequence, the optical signal received by the photodiode 221 is a superimposed optical signal of an optical signal emitted by an LED and an ambient optical signal, wherein the optical signal emitted by the LED is an optical signal formed by reflecting light emitted by the LED in the emitting circuit 21 through skin tissue, the photodiode 221 receives the superimposed optical signal of the optical signal emitted by the LED and the ambient optical signal and converts the superimposed optical signal into a current signal, the transimpedance amplifier 222 receives the current signal and converts the current signal into a voltage signal, the programmable gain amplifier 223 performs gain amplification on the voltage signal, the filter circuit 224 filters the voltage signal, the voltage signal is input to the analog-to-digital converter 225 and converted into a digital signal, the analog-to-digital converter 225 converts the generated first digital code value to the LED dimming circuit 100 of the present invention, the LED dimming circuit 100 processes the signal and outputs an adjusted dimming control signal to the LED driving circuit 211, so as to adaptively adjust the emission current of the LED driving circuit 211. Alternatively, the wearable device 200 may be a smart band, a smart watch, a TWS (True Wireless Stereo) headset, or the like.

The analog-to-digital converter 225 samples the voltage signal during its conversion into a digital signal, which is converted by the analog-to-digital converter 225 into a binary first optical digital code value, which thus corresponds to a voltage value.

In an alternative embodiment, the dimming control signal may be a current control bit, the current control bit represents a driving current for adjusting the energy of the LED pulse, and the larger the current control bit, the larger the driving current; the smaller the current control bit, the smaller the drive current.

Referring to fig. 2, the LED dimming circuit 100 includes a processing and determining module 11 and a dimming control module 10, and the LED dimming circuit 100 includes a dimming state.

The processing and determining module 11 receives a first optical digital code value input by the analog-to-digital converter 225, where the first optical digital code value is a digital signal obtained by receiving and performing analog-to-digital conversion on an optical signal emitted by an LED and an ambient light signal.

The processing and determining module 11 is configured to receive the first optical digital code value in the dimming state, compare the first optical digital code value with a preset target threshold range to obtain a first comparison result, and output dimming information according to the first comparison result. Specifically, it may be determined whether the dimming control signal of the LED driving circuit needs to be adjusted and the adjustment direction when the dimming control signal needs to be adjusted according to the first comparison result, and when the determination result is yes, the dimming control module 10 outputs the dimming information carrying the adjustment direction. When the determination result is no, the processing determining module 11 does not output dimming information.

In this embodiment, two end values of the target threshold range are a target threshold lower limit and a target threshold upper limit, respectively, that is, the target threshold range is from the target threshold lower limit to the target threshold upper limit, and when the first optical digital code value corresponding to the superposition of the optical signal emitted by the LED and the ambient light signal is located in the target threshold range, the corresponding optical signal emitted by the LED is located in an absolute safety interval in the detection range of the receiving circuit.

When the first optical digital code value is compared with a preset target threshold range, the first optical digital code value may be compared with a target lower threshold and a target upper threshold, respectively.

The dimming control module 20 is configured to receive the dimming information output by the processing and determining module 11, and obtain a current dimming control signal; the current dimming control signal is adjusted according to the dimming information, updated according to the adjusted dimming control signal, and output to the LED driving circuit 211.

In an optional embodiment, the processing and determining module 11 is configured to determine that the dimming information is decreased if the first comparison result is that the first optical digital code value is greater than a preset target upper threshold; and if the first comparison result is that the first light digital code value is smaller than a preset target lower limit threshold, determining that the dimming information is increased. Accordingly, the dimming control module 20 is configured to adjust the dimming control signal to decrease the intensity of the light signal emitted by the LED when the dimming information is decreasing; when the dimming information is increasing, the dimming control signal is adjusted to increase the intensity of the light signal emitted by the LED.

In this embodiment, the intensity of the light signal obtained by superimposing the light emitted by the LED and the ambient light is controlled within the detection range corresponding to the target threshold range, so that the adaptive adjustment of the dimming control signal is realized, and the LED dimming efficiency is improved.

In an optional embodiment, the LED dimming circuit 100 further includes a non-dimming state, and the processing and determining module 11 is further configured to switch the dimming state to the non-dimming state when the first comparison result indicates that the first light digital code value is within the target threshold range, or the number of times of adjusting the dimming control signal is greater than or equal to the preset second time threshold.

Further, the non-dimming state includes a threshold adjustment state and a non-threshold adjustment state, and the processing and determining module 11 is further configured to: if the first comparison result is that the first optical digital code value is within the target threshold value range, switching the dimming state into a non-threshold value adjusting state; and if the times of adjusting the dimming control signal are greater than or equal to the preset second time threshold value, switching the dimming state to a threshold value adjusting state.

The first light digital code value is within the target threshold range, which indicates that the aim of dimming is achieved, the dimming control signal does not need to be adjusted, and the dimming state is switched to reduce the energy consumption of the device.

The number of times of adjusting the dimming control signal is counted, and when the number of times of adjusting the dimming control signal is greater than or equal to the preset second time threshold value, the first light digital code value cannot be located within the target threshold value range, which indicates that the problem cannot be solved by adjusting the dimming control signal and the need of continuing dimming is avoided.

Further, the processing and determining module 11 is further configured to: and if the first comparison result is that the first optical digital code value is greater than a preset target upper limit threshold value, or the first optical digital code value is less than a preset target lower limit threshold value, accumulating 1 for the times of adjusting the dimming control signal.

When the first optical digital code value is greater than the preset target upper threshold or less than the preset target lower threshold, it indicates that the first optical digital code value is not within the target threshold range, and the dimming control signal needs to be adjusted, so the number of times of adjusting the dimming control signal needs to be accumulated.

In an alternative embodiment, please refer to fig. 3, the dimming control module 10 further includes a signal forwarding dimming module 12 connected to the processing and determining module 11, and a dimming operation module 13 connected to the signal forwarding dimming module 12.

The signal forwarding dimming module 12 is configured to store a dimming control signal and output the stored dimming control signal to the LED driving circuit, so that the LED driving circuit generates a corresponding driving current according to the received dimming control signal. In the dimming state, the signal forwarding dimming module 12 is configured to receive dimming information and output the dimming information and the current dimming control signal to the dimming operation module 13.

The dimming operation module 13 receives the dimming information and the current dimming control signal input by the signal forwarding dimming module 12, adjusts the current dimming control signal according to the adjustment direction in the input dimming information, and outputs the adjusted dimming control signal to the signal forwarding dimming module 12; after receiving the adjusted dimming control signal, the signal forwarding dimming module 12 updates the current dimming control signal according to the adjusted dimming control signal, and outputs the current dimming control signal to the LED driving circuit. That is, in the next pulse period, the LED driving circuit generates a driving current according to the adjusted dimming control signal to adjust the brightness of the LED light.

In this embodiment, in the dimming state, the processing and determining module 11, the signal forwarding dimming module 12, and the dimming operation module 13 cooperate with each other to perform cyclic iterative adjustment on the dimming control signal until a first light digital code value formed by a light signal obtained by superimposing light emitted by an LED corresponding to the dimming control signal with ambient light is within a target threshold range, stop dimming, and generate a driving current with a constant dimming control signal to drive the LED to emit light, at this time, the LED dimming circuit 100 is in a non-threshold adjustment state, which may also be referred to as a normal operating state.

In the above embodiment, the dimming control module 10 is further divided into the signal transfer dimming module 12 and the dimming operation module 13, the signal transfer dimming module 12 is used for receiving and sending various signals, and the dimming operation module 13 is used for calculating, so that the circuit integration is facilitated.

Further, please refer to fig. 4, a first counter 14 may be configured to count the adjustment times of the dimming control signal, the first counter 14 is connected to the processing and determining module 11, and the processing and determining module 11 performs count control, specifically, the processing and determining module 11 is further configured to reset the count of the first counter 14 to zero after the dimming state is switched to the non-threshold adjustment state; after the dimming state is switched to the threshold adjustment state, the count of the first counter 14 is reset to zero.

In this embodiment, the second count threshold may be set according to the bit width of the driving current, for example, when the bit width of the driving current is 8 bits, the second count threshold may be set to 8 times.

Further, the following describes the calculation of the dimming control signal in detail, taking the dimming control signal as the current control bit as an example. The step of adjusting the current control bit by the dimming operation module 13 specifically includes: if the adjustment direction is increased, taking half of the difference between the upper limit of the current bit and the current control bit as an increased value, updating the lower limit of the current bit according to the current control bit, and taking the sum of the current control bit and the increased value as an adjusted current control bit; and if the adjustment direction is decreasing, taking a half of the difference between the current control bit and the lower limit of the current limit as a decreasing value, updating the upper limit of the current limit according to the current control bit, and taking the difference between the current control bit and the decreasing value as the adjusted current control bit.

Wherein the initial values of the upper current limit and the lower current limit are determined according to the number of bits of the analog-to-digital converter 225, for example, the value of the 8-bit analog-to-digital converter 225 is from 0 to 255; the 16-bit analog-to-digital converter 225 has a value of 0 to 65535. Thus, at 8 bits, the initial values of the upper and lower current bit limits are 255 and 0, respectively, and preferably, the initial values of the upper and lower current bit limits may be 200 and 0, respectively. In the current control bit adjusting process, circulation is carried out according to the steps until a first light digital code value formed by superposition of light emitted by the LED and ambient light falls into an adjusted target threshold range, and then the upper limit and the lower limit of the current bit are reset to initial values; or when the dimming number reaches the second threshold value and the dimming state is switched to the threshold adjustment state, resetting the upper current limit and the lower current limit to initial values.

The threshold adjustment state of the LED dimming circuit is explained as follows:

in an actual use environment, the ambient light is complex, for example, in the open air, the ambient light is sunlight; in the room, the ambient light is lamplight; the light collected by the receiving circuit is actually superimposed light of ambient light and light emitted by the LED, and if the ambient light is too strong, the light emitted by the LED is greatly interfered. In this embodiment, if the number of times of performing the cyclic iterative adjustment on the dimming control signal exceeds the preset second number threshold, it is still impossible to make the first light digital code value corresponding to the superimposed light of the light emitted by the LED and the ambient light be within the target threshold range, which indicates that the usage environment has changed, the ambient light becomes strong, the target threshold range needs to be adjusted, and the LED dimming circuit 100 needs to be switched to the threshold adjustment state.

In an alternative embodiment, the dimming control module 10 may be configured to stop outputting the current dimming control signal to the LED driving circuit in the threshold adjustment state, that is, in the threshold adjustment state, the LED does not emit light, and the receiving circuit collects ambient light.

The LED dimming circuit 100 of the present embodiment further includes a target threshold operation module 15, and the processing and determining module 11 and the target threshold operation module 15 cooperate with each other to realize the target threshold adjustment.

The processing and determining module 11 is further configured to receive a second optical digital code value in a threshold adjustment state, compare the second optical digital code value with a preset target threshold range to obtain a second comparison result, and output threshold adjustment information according to the second comparison result, where the second optical digital code value is a digital signal obtained by receiving and performing analog-to-digital conversion on an ambient light signal; the target threshold value operation module 15 is configured to receive threshold value adjustment information input by the processing and determining module, adjust a current target threshold value range according to the threshold value adjustment information, and output the adjusted target threshold value range to the processing and determining module; the processing and determining module 11 is further configured to update the current target threshold range according to the adjusted target threshold range.

Specifically, the threshold adjustment information may include a second optical digital code value, and in the threshold adjustment state, the processing and determining module 11 determines whether the target threshold range needs to be adjusted according to a second comparison result, and outputs the threshold adjustment information carrying the second optical digital code value if the determination result is yes.

In this embodiment, if the second light digital code value is greater than or equal to the target lower threshold, it means that the ambient light has a large influence on the light emitted from the LED, and the target threshold range needs to be adjusted.

Further, the processing and determining module 11 is further configured to: in the threshold adjustment state, if the second comparison result is that the second optical digital code value is greater than or equal to the target lower limit threshold, outputting threshold adjustment information; and if the second comparison result is that the second optical digital code value is smaller than the target lower limit threshold, not outputting the threshold adjustment information, and switching the threshold adjustment state into the dimming state. That is, after the target threshold range is adjusted, if the second comparison result is that the second optical digital code value is smaller than the adjusted target lower threshold, it is determined that the target threshold range does not need to be adjusted, and the threshold adjustment state is switched to the dimming state.

And the processing judgment module 11 and the target threshold operation module 15 are matched to perform cyclic iterative adjustment on the target threshold range until the second light digital code value is smaller than the target lower limit threshold, at the moment, the dimming control signal is switched to the dimming state again, and the iterative adjustment is performed on the dimming control signal until the first light digital code value obtained by superposing the light emitted by the LED and the ambient light falls into the adjusted target threshold range. Of course, it will be understood by those skilled in the art that the target lower threshold may be increased simultaneously with the target upper threshold.

In the present embodiment, by adjusting the target threshold range, it is possible to adapt to changes in ambient light, thereby improving flexibility in adjusting the dimming control signal and further improving dimming efficiency.

Further, the step of increasing and adjusting the target lower threshold by the target threshold operation module 15 specifically includes: taking half of the difference between the upper threshold bit limit and the second optical digital code value as an accumulated value; updating a lower threshold bit limit according to the second optical digital code value; and taking the sum of the target lower limit threshold value and the accumulated value as the adjusted target lower limit threshold value.

Wherein the initial values of the upper threshold limit and the lower threshold limit are determined according to the number of bits of the analog-to-digital converter 225, for example, the value of the 8-bit analog-to-digital converter 225 is from 0 to 255; the 16-bit analog-to-digital converter 225 has a value of 0 to 65535. Accordingly, in the case of 8 bits, the initial values of the upper threshold bit limit and the lower threshold bit limit are 255 and 0, respectively. And in the threshold value range adjusting process, circulating according to the steps until the second optical digital code value is smaller than the target lower threshold value, and resetting the upper limit and the lower limit of the threshold value to initial values.

The following describes a non-threshold adjustment state of the LED dimming circuit:

in an alternative embodiment, in the non-threshold adjustment state, the dimming control signal is constant, and at this time, the processing and determining module 11 is configured to: receiving a first optical digital code value in a non-threshold adjustment state, comparing the first optical digital code value with a preset overflow threshold range, and judging whether the first optical digital code value is out of the overflow threshold range, wherein the first optical digital code value is a digital signal obtained by receiving and performing analog-to-digital conversion on an optical signal emitted by an LED and an ambient optical signal; and if the number of times that the first light digital code value is out of the overflow threshold range is greater than or equal to a preset first time threshold, switching the non-threshold adjustment state into the dimming state.

Specifically, the overflow threshold range includes an overflow upper threshold and an overflow lower threshold; the processing and judging module 11 is further configured to: in a non-threshold adjustment state, if the first optical digital code value is larger than an overflow upper threshold or smaller than an overflow lower threshold, accumulating 1 for the times that the first optical digital code value is out of the overflow threshold range; if the times of the first optical digital code value outside the overflow threshold range are greater than or equal to a preset first time threshold, switching the non-threshold adjustment state into a dimming state, and returning the times of the first optical digital code value outside the overflow threshold range to zero; the target threshold range comprises a target lower limit threshold and a target upper limit threshold, and the overflow upper limit threshold, the target lower limit threshold and the overflow lower limit threshold are sequentially reduced.

Further, a second counter 16 may be configured to count the number of times that the first optical digital code value is outside the overflow threshold range, the second counter 16 is connected to the processing and determining module 11, and the processing and determining module 11 performs count control, specifically, if the first optical digital code value is greater than the overflow upper threshold or the first optical digital code value is less than the overflow lower threshold, the second counter 16 counts the number of times that the first optical digital code value exceeds the overflow threshold by 1; if the number of times of exceeding the overflow threshold is greater than or equal to the preset first time threshold, the non-threshold adjustment state is switched to the dimming state, and the count of the second counter 16 is reset to zero.

The overflow threshold range is determined according to the detection range of the receiving circuit, the interval of the overflow threshold range is larger than the interval of the target threshold range, the first optical digital code value is outside the overflow threshold range, the situation that the superposition of the light emitted by the LED and the ambient light is not in the detection range of the receiving circuit may occur, when the number of times that the first optical digital code value is outside the overflow threshold range reaches the preset first threshold value, the probability that the superposition of the light emitted by the LED and the ambient light is not in the detection range of the receiving circuit is further increased, and the dimming state needs to be switched to the dimming state for dimming. Alternatively, the overflow threshold range may be adjusted between a maximum of 18bit signed numbers, i.e., may be set between-262142-262143.

In the embodiment, the dimming state can be rapidly entered by setting the overflow threshold range and switching to the dimming state when the number of times of the overflow threshold range reaches the first preset threshold.

Optionally, in the dimming circuit 100 of this embodiment, the overflow threshold range and the target threshold range may both correspond to the number of bits of the analog-to-digital converter and whether there is an output symbol, for example, if the analog-to-digital converter is 18 bits and the output is signed, the overflow threshold range is adjusted between the 18 bits and the signed number, that is, the overflow threshold range may be set between-262142 and 262143, and the target threshold range is set between the overflow threshold ranges; for another example, if the adc is 8 bits and the output is unsigned, the overflow threshold range is adjusted between 8 bits and unsigned number, i.e. it can be set between 0 and 255, and the target threshold range is set between the overflow threshold ranges.

In an alternative embodiment, to increase the flexibility of dimming, the voltage signals of the superposition of the light emitted by the LEDs of different phases and the ambient light may be sampled separately. The LED light signal is a periodic pulse signal, different collection times can be set in one pulse cycle, each collection time corresponds to one phase, which can also be referred to as a conversion phase, in this embodiment, one pulse cycle has N collection times, N is a natural number greater than or equal to 1, so that there are N phases in one pulse cycle, each phase can be configured with different driving currents, that is, each phase can be configured with different dimming control signals, each phase can be used as an independent node for dimming, and the generated dimming control signal after being adjusted takes effect in the corresponding phase of the next pulse cycle. For example, the pulse period of the LED, or PRF (pulse repetition frequency), is generally adjustable, and the circuit of the present invention can be adapted to PRF between a minimum of 1Hz and 1000 Hz. The processing and judging module 11 comprises a plurality of processing and judging units, each of which receives a first optical digital code value of one phase and outputs dimming information of the corresponding phase; the dimming control module 10 includes a plurality of dimming control units, each of which receives dimming information of one phase, acquires a current dimming control signal of the corresponding phase, and outputs an adjusted dimming control signal of the corresponding phase according to the dimming information of the corresponding phase and the dimming control signal.

Specifically, the analog-to-digital converter 225 is configured to convert the voltage amplitudes of the input voltage signal at different phases into first optical digital code values of different phases, respectively, and the analog-to-digital converter 225 outputs a time sequence data formed by a plurality of first optical digital code values, for example, the first optical digital code values of N different phases in total, and the output time sequence data is the first optical digital code value_t1First optical digital code value_t2… … first optical digital code value_tNCorrespondingly, there are N dimming nodes, the dimming control module 10 includes a signal forwarding dimming module 12 and a dimming operation module 13, and the processing and determining module 11, the signal forwarding dimming module 12 and the dimming operation module 13 are respectively provided with N corresponding units, please refer to fig. 4, each duty cycle of the LED dimming circuit 100 includes a plurality of phases, the processing and determining module 11 includes a plurality of processing and determining units 111, and each processing and determining unit 111 receives a first optical digital code value of one phase and outputs dimming information of the corresponding phase; the signal repeating dimming module 12 includes a plurality of signal repeating dimming units 121, and each signal repeating dimming unit 121 receives dimming information of one phase and outputs dimming information of a corresponding phase and current dimming control of the corresponding phaseSignal preparation; the dimming operation module 13 includes a plurality of dimming operation units 131, and each dimming operation unit 131 receives dimming information of one phase and a current dimming control signal, and outputs an adjusted dimming control signal of a corresponding phase to the corresponding signal forwarding dimming unit 121. The functions and execution flows of the processing determination unit 111, the signal transfer dimming unit 121, and the dimming operation unit 131 are described in the foregoing embodiments with reference to the processing determination module 11, the signal transfer dimming module 12, and the dimming operation module 13.

Further, referring to fig. 4, the processing and determining module 11 further includes a first register 112 for storing the target threshold range, and the signal forwarding dimming module 12 further includes a second register 122 for storing the current control bit.

The dimming circuit 100 further includes a register configuration module 17 connected to the processing and determining module 11 and the signal forwarding dimming module 12, and configured to obtain a target threshold range and a dimming control signal when receiving a trigger signal generated by a user triggering a power key or a dimming switch; configuring the first register 112 according to the target threshold range; the second register 122 is configured according to the dimming control signal. Specifically, after the user turns on or turns on the dimming switch, the initial target threshold range and the dimming control signal are configured, and the target threshold range and the dimming control signal acquired by the register configuration module 17 may be the preset initial target threshold range and the preset dimming control signal, or may be the target threshold range and the dimming control signal recorded last time.

The dimming circuit 100 further includes an asynchronous signal processing module 18 disposed between the processing and determining module 11 and the signal forwarding dimming module 12, and configured to synchronize a phase of the dimming information output by the processing and determining unit 111 with a phase of the signal forwarding dimming module 12.

Fig. 5 is a flowchart illustrating an LED dimming method according to a second embodiment of the present invention. It should be noted that the method of the present invention is not limited to the flow sequence shown in fig. 5 if the results are substantially the same. The LED dimming method of the present embodiment can be implemented by the LED dimming circuit 100 of the first embodiment, and can also be implemented by a software program, and the content of the present embodiment related to the first embodiment is specifically referred to above, and is not described in detail herein. As shown in fig. 5, the LED dimming method mainly includes the following steps:

and S110, in the dimming state, comparing the acquired first optical digital code value with a preset target threshold range to obtain a first comparison result.

The first optical digital code value is a digital signal obtained by receiving and performing analog-to-digital conversion on an optical signal emitted by the LED and an ambient optical signal.

And S120, acquiring dimming information according to the first comparison result.

The target threshold range comprises a target lower threshold and a target upper threshold. Optionally, in this step, if the first comparison result is that the first optical digital code value is greater than a preset target upper threshold, it is determined that the dimming information is decreased; and if the first comparison result is that the first light digital code value is smaller than a preset target lower limit threshold, determining that the dimming information is increased. Further, if the first comparison result is that the first light digital code value is greater than or equal to the target lower threshold and less than or equal to the target upper threshold, the dimming information is not output.

And S130, adjusting the current dimming control signal according to the dimming information.

Optionally, in this step, when the dimming information is a decrease, the dimming control signal is adjusted to decrease the intensity of the light signal emitted by the LED; when the dimming information is increasing, the dimming control signal is adjusted to increase the intensity of the light signal emitted by the LED.

And S140, updating the current dimming control signal according to the adjusted dimming control signal, and outputting the updated current dimming control signal to the LED driving circuit.

Fig. 6 is a flowchart illustrating an LED dimming method according to a third embodiment of the present invention. The present embodiment further includes, after step S110, on the basis of the second embodiment:

and S210, when the first comparison result shows that the first light digital code value is within the range of the target threshold value, or the number of times of adjusting the dimming control signal is greater than or equal to the preset second time threshold value, switching the dimming state to a non-dimming state.

Wherein the non-dimming state comprises a threshold adjustment state and a non-threshold adjustment state. Optionally, step S210 specifically includes:

s211, if the first comparison result is that the first optical digital code value is within the target threshold range, switching the dimming state to a non-threshold adjustment state;

s212, if the number of times of adjusting the dimming control signal is greater than or equal to the preset second number threshold, the dimming state is switched to the threshold adjustment state.

Fig. 7 is a flowchart illustrating an LED dimming method according to a fourth embodiment of the present invention. The present embodiment further includes, after step S212, on the basis of the third embodiment:

and S310, receiving a second optical digital code value in the threshold adjusting state, and comparing the second optical digital code value with a preset target threshold range to obtain a second comparison result.

The second optical digital code value is a digital signal obtained by receiving and performing analog-to-digital conversion on the ambient light signal.

And S320, outputting threshold adjustment information according to the second comparison result, and adjusting the current target threshold range according to the threshold adjustment information.

The target threshold range comprises a target lower threshold and a target upper threshold. Optionally, in the process of outputting the threshold adjustment information according to the second comparison result, if the second comparison result is that the second optical digital code value is greater than or equal to the target lower threshold, the threshold adjustment information is output; and if the second comparison result is that the second optical digital code value is smaller than the target lower limit threshold, not outputting the threshold adjustment information, and switching the threshold adjustment state into the dimming state.

S330, updating the current target threshold range according to the adjusted target threshold range.

In this embodiment, the target threshold range is adjusted to adapt to the change of ambient light, so that the flexibility of adjusting the dimming control signal is improved, and the dimming efficiency is further improved.

Fig. 8 is a flowchart illustrating an LED dimming method according to a fifth embodiment of the present invention. This embodiment further includes, after step S211, on the basis of the third embodiment:

s410, in the non-threshold adjustment state, receiving the first optical digital code value, comparing the first optical digital code value with a preset overflow threshold range, and judging whether the first optical digital code value is out of the overflow threshold range.

And S420, if the number of times that the first optical digital code value is out of the overflow threshold range is greater than or equal to a preset first time threshold, switching the non-threshold adjustment state into the dimming state.

In this embodiment, the setting of the overflow threshold range and the switching to the dimming state when the number of times of the overflow threshold range reaches the first preset threshold are beneficial to entering the dimming state quickly.

Fig. 9 is a flowchart illustrating an LED dimming method according to a sixth embodiment of the present invention. It should be noted that the method of the present invention is not limited to the flow sequence shown in fig. 9 if the results are substantially the same. The LED dimming method of the present embodiment is implemented by the LED dimming circuit 100 of the first embodiment, and may also be implemented by a software program, and the content of the present embodiment related to the first embodiment is specifically referred to above, and is not described in detail herein. In this embodiment, the dimming control signal is a current control bit, as shown in fig. 9, the LED dimming method mainly includes the following steps:

s101, in a dimming state, comparing the acquired first optical digital code value with a preset target threshold range to obtain a first comparison result.

And S102, determining whether the current control bit of the LED driving circuit needs to be adjusted and the adjustment direction when the current control bit needs to be adjusted according to the first comparison result.

Wherein, step S102 specifically includes: and S1021, if the first comparison result is that the first optical digital code value is larger than the preset target upper limit threshold, determining that the current control bit needs to be adjusted and the adjustment direction is reduced, and accumulating the count of the dimming times by 1. S1022, if the first comparison result indicates that the first optical digital code value is smaller than the preset target lower threshold, it is determined that the current control bit needs to be adjusted and the adjustment direction is increased, and the count of the dimming times is incremented by 1. And S1023, if the first comparison result is that the first light digital code value is smaller than or equal to the target upper limit threshold and larger than or equal to the target lower limit threshold, determining that the current control bit does not need to be adjusted, switching the dimming state to a normal working state, and returning the counting of the dimming times to zero. And S1024, if the dimming frequency is larger than the preset second frequency threshold, switching the dimming state to a threshold adjusting state, and returning the counting of the dimming frequency to zero.

And S103, if the determination result is yes, adjusting the current control bit according to the adjustment direction, and sending the adjusted current control bit to the LED driving circuit.

The adjusting process of the current control bit in step S103 may include: s1031, if the adjusting direction is increasing, taking half of the difference between the upper limit of the current bit and the current control bit as an increasing value, updating the lower limit of the current bit according to the current control bit, and taking the sum of the current control bit and the increasing value as the adjusted current control bit; s1032 sets a half of a difference between the current control bit and the lower limit of the current bit as a decrease value if the adjustment direction is decreasing, updates the upper limit of the current bit according to the current control bit, and sets the difference between the current control bit and the decrease value as the adjusted current control bit.

In an optional embodiment, after step S1024, the method further includes:

s201, in the threshold adjustment state, stopping outputting the current control bit to the LED driving circuit.

S202, comparing the input second optical digital code value with a preset target threshold range to obtain a second comparison result.

And S203, determining whether the target threshold range needs to be adjusted according to the second comparison result.

Wherein, step S203 specifically includes: s2031, in the threshold value adjusting state, comparing the input second optical digital code value with a preset target threshold value range to obtain a second comparison result; s2032, if the second comparison result is that the second optical digital code value is greater than or equal to the target lower threshold, determining that the target threshold range needs to be adjusted; s2033, if the second comparison result is that the second optical digital code value is smaller than the target lower threshold, it is determined that the target threshold range does not need to be adjusted, and the threshold adjustment state is switched to the dimming state, at this time, the process returns to step S101.

And S204, if the determination result is yes, increasing and adjusting the target lower threshold of the current target threshold range according to the second optical digital code value, and updating the current target threshold range according to the adjusted target threshold range.

The tuning process of the target threshold range in step S204 specifically includes: s2041, taking half of the difference value between the upper limit of the threshold bit and the second optical digital code value as an accumulated value; s2042, updating the lower limit of the threshold value according to the second optical digital code value; and S2043, taking the sum of the target lower limit threshold value and the accumulated value as the adjusted target lower limit threshold value. Of course, the target upper threshold value may be adjusted at the same time, and the sum of the target upper threshold value and the accumulated value may be set as the adjusted target upper threshold value in step S2043.

And S205, if the determination result is negative, switching the threshold value adjusting state to the dimming state. At this time, the process returns to step S101.

In an optional embodiment, after step S1023, the method further includes:

s301, in a non-threshold adjustment state, comparing the input first optical digital code value with a preset overflow threshold range to obtain a third comparison result, wherein the overflow threshold range comprises an overflow upper threshold and an overflow lower threshold.

S302, if the first optical digital code value is larger than the overflow upper threshold or the first optical digital code value is smaller than the overflow lower threshold, the count of the number of times of exceeding the overflow threshold by the second counter is accumulated by 1.

And S303, if the number of times of exceeding the overflow threshold is greater than or equal to the preset first time threshold, switching the non-threshold adjusting state into the dimming state, and resetting the count of the second counter to zero.

The following steps are also included before step S101:

s401, receiving a trigger signal generated by a user triggering a power key or a dimming switch, and acquiring a current target threshold range and an initial current control bit;

s402, acquiring and storing an ambient light code value;

and S403, switching to a dimming state, and sending an initial current control bit to the LED driving circuit. At this time, the process proceeds to step S101.

Specifically, when the power supply of the wearable device is turned on or the dimming switch is turned on, first performing S401 to S403 to perform initial configuration; then entering a dimming state, executing steps S101-S103 to perform dimming to obtain a most suitable current control bit under the current environment, if the dimming is successful, entering a non-threshold adjustment state, executing steps S301-S303 to perform normal detection, returning to step S101 when the detection is abnormal under the non-threshold adjustment state, and entering the dimming state again; if the dimming fails, the system enters a threshold adjustment state, executes steps S201 to S205 to adjust the target threshold range, and returns to step S101 to enter the dimming state again after the threshold range adjustment is completed. The wearable device is in operation, switching between a dimming state, a non-threshold adjustment state, and a threshold adjustment state.

Fig. 10 is a schematic structural diagram of an LED dimming device according to a seventh embodiment of the present invention. The LED dimming device corresponds to the LED dimming method in the second embodiment one to one. As shown in fig. 10, the LED dimming device 50 includes: the device comprises a comparison module 51, a judgment module 52, an adjustment module 53 and an update module 54, wherein the comparison module 51 is configured to compare an acquired first optical digital code value with a preset target threshold range in a dimming state to obtain a first comparison result, where the first optical digital code value is a digital signal obtained by receiving and performing analog-to-digital conversion on an optical signal emitted by an LED and an ambient optical signal; the judging module 52 is configured to obtain dimming information according to the first comparison result; an adjusting module 53, configured to adjust the current dimming control signal according to the dimming information; and an updating module 54, configured to update the current dimming control signal according to the adjusted dimming control signal, and output the updated current dimming control signal to the LED driving circuit.

Fig. 11 is a schematic structural diagram of a chip according to an eighth embodiment of the present invention. As shown in fig. 11, the chiplet 61 includes an LED dimming circuit 100.

Fig. 12 is a schematic structural diagram of a wearable device according to a ninth embodiment of the present invention. As shown in fig. 12, the wearable device 62 includes an LED dimming circuit 100.

Fig. 13 is a schematic structural diagram of a wearable device according to a tenth embodiment of the present invention. As shown in fig. 13, the wearable device 70 includes a processor 71 and a memory 72 coupled to the processor 71.

The memory 72 stores program instructions for implementing the LED dimming method of any of the embodiments described above.

Processor 71 is operative to execute program instructions stored in memory 72 for LED dimming.

The processor 71 may also be referred to as a CPU (Central Processing Unit). The processor 71 may be an integrated circuit chip having signal processing capabilities. The processor 71 may also be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

Referring to fig. 14, fig. 14 is a schematic structural diagram of a storage medium 80 according to an eleventh embodiment of the invention. A storage medium 80 of an embodiment of the present invention, which may be either non-volatile or volatile, stores program instructions 81 that enable all of the methods described above to be implemented. The program instructions 81 may be stored in the storage medium in the form of a software product, and include several instructions to enable a computer device (which may be a personal computer, a server, or a network device) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a mobile hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, or terminal devices, such as a computer, a server, a mobile phone, and a tablet.

While the foregoing is directed to embodiments of the present invention, it will be understood by those skilled in the art that various changes may be made without departing from the spirit and scope of the invention.

Claims

1. An LED dimming circuit is characterized by comprising a processing and judging module and a dimming control module;

2. The LED dimming circuit of claim 1, wherein the processing and determining module is further configured to switch the dimming state to the non-dimming state when the first comparison result indicates that the first light digital code value is within the target threshold range, or the dimming control signal is adjusted for a number of times greater than or equal to a preset second time threshold.

3. The LED dimming circuit of claim 2, wherein the non-dimming state comprises a threshold adjustment state and a non-threshold adjustment state, and wherein the processing and determining module is further configured to: if the first comparison result is that the first optical digital code value is within the target threshold range, switching the dimming state to a non-threshold adjustment state; and if the times of adjusting the dimming control signal is greater than or equal to a preset second time threshold value, switching the dimming state to a threshold value adjusting state.

4. The LED dimming circuit of claim 2 or 3, wherein the non-dimming state comprises a threshold adjustment state;

the processing and judging module is further configured to receive a second optical digital code value in a threshold adjustment state, compare the second optical digital code value with a preset target threshold range to obtain a second comparison result, and output threshold adjustment information according to the second comparison result, where the second optical digital code value is a digital signal obtained after receiving and performing analog-to-digital conversion on an ambient light signal;

the LED dimming circuit further comprises a target threshold value operation module, which is used for receiving the threshold value adjustment information input by the processing and judging module, adjusting the current target threshold value range according to the threshold value adjustment information, and outputting the adjusted target threshold value range to the processing and judging module;

the processing and judging module is also used for updating the current target threshold range according to the adjusted target threshold range.

5. The LED dimming circuit of claim 4, wherein the target threshold range comprises a target lower threshold and a target upper threshold;

the processing and judging module is further used for: in a threshold adjustment state, if the second comparison result is that the second optical digital code value is greater than or equal to the target lower threshold, outputting the threshold adjustment information; and if the second comparison result is that the second optical digital code value is smaller than the target lower limit threshold, not outputting the threshold adjustment information, and switching the threshold adjustment state into a dimming state.

6. The LED dimming circuit of claim 2 or 3, wherein the non-dimming state comprises a non-threshold adjustment state;

the processing and judging module is further configured to receive a first optical digital code value in a non-threshold adjustment state, compare the first optical digital code value with a preset overflow threshold range, and judge whether the first optical digital code value is outside the overflow threshold range; and if the number of times that the first light digital code value is out of the overflow threshold range is greater than or equal to a preset first time threshold, switching the non-threshold adjustment state into the dimming state.

7. The LED dimming circuit of claim 6, wherein the overflow threshold range comprises an overflow upper threshold and an overflow lower threshold;

the processing and judging module is further configured to, in a non-threshold adjustment state, add 1 to the number of times that the first optical digital code value is outside the overflow threshold range if the first optical digital code value is greater than the overflow upper threshold or the first optical digital code value is less than the overflow lower threshold; if the number of times that the first optical digital code value is out of the overflow threshold range is larger than or equal to a preset first time threshold, switching a non-threshold adjustment state into a dimming state, and returning the number of times that the first optical digital code value is out of the overflow threshold range to zero;

the target threshold range comprises a target lower threshold and a target upper threshold, and the overflow upper threshold, the target lower threshold and the overflow lower threshold decrease sequentially.

8. The LED dimming circuit of claim 2, wherein the target threshold range comprises a target lower threshold and a target upper threshold; the processing and judging module is further used for: and if the first comparison result is that the first optical digital code value is greater than a preset target upper limit threshold value, or the first optical digital code value is less than a preset target lower limit threshold value, accumulating 1 for the times of adjusting the dimming control signal.

9. The LED dimming circuit of claim 2, wherein the processing and determining module is further configured to: if the first comparison result is that the first optical digital code value is larger than a preset target upper limit threshold, determining that the dimming information is reduced; if the first comparison result is that the first light digital code value is smaller than a preset target lower limit threshold, determining that the dimming information is increased; correspondingly, the dimming control module is further configured to: when the dimming information is a decrease, adjusting the dimming control signal to decrease the intensity of the light signal emitted by the LED; when the dimming information is an increase, adjusting the dimming control signal to increase the intensity of the light signal emitted by the LED.

10. The LED dimming circuit according to claim 1 or 2, wherein each duty cycle of the LED dimming circuit comprises a plurality of phases, and the processing and determining module comprises a plurality of processing and determining units, each of the processing and determining units receiving the first optical digital code value of one phase and outputting dimming information corresponding to the phase; the dimming control module comprises a plurality of dimming control units, each dimming control unit receives dimming information of one phase, acquires the current dimming control signal of the corresponding phase, and outputs the adjusted dimming control signal of the corresponding phase according to the dimming information of the corresponding phase and the dimming control signal.

11. The LED dimming circuit of claim 1, wherein the processing and determining module further comprises a first register for storing the target threshold range, and the dimming control module further comprises a second register for storing the dimming control signal;

the dimming circuit further comprises a register configuration module connected with the processing and judging module and the dimming control module and used for configuring the first register according to a pre-stored initial target threshold range; configuring the second register according to a pre-stored initial dimming control signal;

the dimming circuit further comprises an asynchronous signal processing module arranged between the processing and judging module and the dimming control module and used for synchronizing the phase of the dimming information output by the processing and judging module with the phase of the dimming control module.

12. A chip comprising the LED dimming circuit of any one of claims 1 to 11.

13. A wearable device, characterized in that the wearable device comprises the LED dimming circuit of any of claims 1 to 11.

14. An LED dimming method, comprising:

acquiring dimming information according to the first comparison result;

adjusting the current dimming control signal according to the dimming information;

15. The LED dimming method according to claim 14, wherein after comparing the obtained first light digital code value with a preset target threshold range to obtain a first comparison result in the dimming state, the method further comprises:

and when the first comparison result shows that the first light digital code value is within the target threshold range, or the number of times of adjusting the dimming control signal is greater than or equal to a preset second time threshold, switching the dimming state to a non-dimming state.

16. The LED dimming method of claim 15, wherein the non-dimming state comprises a threshold adjustment state and a non-threshold adjustment state; when the first comparison result indicates that the first light digital code value is within the target threshold range, or the number of times of adjusting the dimming control signal is greater than or equal to a preset second time threshold, switching the dimming state to the non-dimming state includes:

if the first comparison result is that the first optical digital code value is within the target threshold range, switching the dimming state to a non-threshold adjustment state;

and if the times of adjusting the dimming control signal is greater than or equal to a preset second time threshold value, switching the dimming state to a threshold value adjusting state.

17. The LED dimming method according to claim 15 or 16, wherein the target threshold range comprises a target lower threshold and a target upper threshold;

the obtaining of dimming information according to the first comparison result includes:

if the first comparison result is that the first optical digital code value is larger than a preset target upper limit threshold, determining that the dimming information is reduced;

if the first comparison result is that the first light digital code value is smaller than a preset target lower limit threshold, determining that the dimming information is increased;

correspondingly, the adjusting the current dimming control signal according to the dimming information includes:

when the dimming information is a decrease, adjusting the dimming control signal to decrease the intensity of the light signal emitted by the LED;

when the dimming information is an increase, adjusting the dimming control signal to increase the intensity of the light signal emitted by the LED.

18. The LED dimming method of claim 16, wherein after switching the dimming state to the threshold adjustment state, further comprising:

receiving a second optical digital code value in a threshold adjustment state, and comparing the second optical digital code value with a preset target threshold range to obtain a second comparison result, wherein the second optical digital code value is a digital signal obtained after receiving and performing analog-to-digital conversion on an ambient light signal;

outputting threshold adjustment information according to the second comparison result, and adjusting the current target threshold range according to the threshold adjustment information;

and updating the current target threshold range according to the adjusted target threshold range.

19. The LED dimming method of claim 18, wherein the target threshold range comprises a target lower threshold and a target upper threshold;

the outputting threshold adjustment information according to the second comparison result includes:

if the second comparison result is that the second optical digital code value is greater than or equal to the target lower limit threshold, outputting the threshold adjustment information;

and if the second comparison result is that the second optical digital code value is smaller than the target lower limit threshold, not outputting the threshold adjustment information, and switching the threshold adjustment state into a dimming state.

20. The LED dimming method of claim 16, wherein after switching the dimming state to the non-threshold adjustment state, further comprising:

under a non-threshold adjustment state, receiving a first optical digital code value, comparing the first optical digital code value with a preset overflow threshold range, and judging whether the first optical digital code value is out of the overflow threshold range;

and if the number of times that the first light digital code value is out of the overflow threshold range is greater than or equal to a preset first time threshold, switching the non-threshold adjustment state into the dimming state.