Electronic focusing control circuit for liquid lens

Abstract

The utility model relates to the field of stage lighting, and particularly discloses a liquid lens electronic focusing control circuit which comprises a main control chip, an in-phase amplifying circuit, an H-bridge alternating current signal generating circuit and a liquid lens. One PWM pulse signal output end of the main control chip is electrically connected with the input end of the in-phase amplifying circuit, and the other PWM pulse signal output end of the main control chip is electrically connected with the PWM pulse signal input end of the H-bridge alternating current signal generating circuit. The voltage output end of the in-phase amplification circuit is electrically connected with the voltage input end of the H-bridge alternating current signal generation circuit, and the in-phase amplification circuit receives different PWM pulse signals output by the main control chip and provides different voltages for the H-bridge alternating current signal generation circuit; the output end of the H-bridge alternating current signal generating circuit is electrically connected with the input end of the liquid lens, and after PWM pulse signals input by the main control chip drive the H-bridge circuit to work, the H-bridge alternating current signal generating circuit receives different voltages provided by the in-phase amplifying circuit and generates alternating current signals with variable amplitude to drive the liquid lens to generate atomization of the corresponding degree.

Description

Technical Field

[0001] The utility model relates to the field of stage lighting, in particular to a liquid lens electronic focusing control circuit. Background Art

[0002] With the continuous development of the lighting industry, whether it is home, commercial or professional stage lighting, there is a demand for lamps to adjust the focal length of the lights, especially in the field of commercial and stage lighting.

[0003] At present, the mainstream approach to adjusting the focal length of lights is to use stepper motors and mechanical structures to drive the optical structure or even the entire light source structure to expand and contract, thereby achieving the effect of adjusting the focal length of lights. Since the entire focusing system includes motor drive circuit modules, motors, transmission shafts and other mechanical structure modules, the volume and weight of the lamp body increase. In addition, when the motors and transmission shafts and other mechanical structures move, noise will inevitably be generated. In addition, the focusing process requires reaction time and motor movement time, and when a fault occurs, disassembly and maintenance are cumbersome and complicated. Utility Model Content

[0004] The utility model aims to provide a liquid lens electronic focus control circuit which controls the liquid lens through a circuit to adjust the focal length of a light, so as to reduce the volume and weight of the lamp body and reduce noise.

[0005] The liquid lens electronic focusing control circuit of the utility model comprises a main control chip, a common-phase amplifier circuit, an H-bridge AC signal generating circuit, and a liquid lens;

[0006] The main control chip has one PWM pulse signal output terminal electrically connected to the input terminal of the in-phase amplifier circuit, and another PWM pulse signal output terminal electrically connected to the PWM pulse signal input terminal of the H-bridge AC signal generating circuit;

[0007] The in-phase amplifier circuit has a voltage output terminal electrically connected to a voltage input terminal of an H-bridge AC signal generating circuit, and receives different PWM pulse signals output by a main control chip to provide different voltages for the H-bridge AC signal generating circuit;

[0008] The H-bridge AC signal generating circuit has an output end electrically connected to the input end of the liquid lens. After the PWM pulse signal input by the main control chip drives the H-bridge circuit to work, it receives different voltages provided by the in-phase amplifier circuit to generate an AC signal with variable amplitude to drive the liquid lens to produce a corresponding degree of atomization.

[0009] In the liquid lens electronic focusing control circuit described in the utility model, the main control chip controls the in-phase amplifier circuit through PWM to cooperate with the H-bridge AC signal generating circuit to generate an AC signal with a variable amplitude to drive the liquid lens to produce different degrees of atomization effects. When the light beam emitted by the light source passes through the atomized liquid lens, the beam angle will change, thereby achieving the effect of adjusting the focal length. The entire adjustment process is at the millisecond level, and because it does not require structures such as motors and the required current is very small, the noise is extremely low, and the volume and weight of the lamp body are also greatly reduced.

[0010] As a preferred solution of the utility model, the main control chip includes a Power PWM pulse signal output terminal, a 1A PWM pulse signal output terminal, a 2A PWM pulse signal output terminal, a 1B PWM pulse signal output terminal, and a 2B PWM pulse signal output terminal; the Power PWM pulse signal output terminal is electrically connected to the input terminal of the in-phase amplifier circuit; the 1A PWM pulse signal output terminal, the 2A PWM pulse signal output terminal, the 1B PWM pulse signal output terminal, and the 2B PWM pulse signal output terminal are electrically connected to the PWM pulse signal input terminal of the H-bridge AC signal generating circuit.

[0011] As a preferred solution of the present utility model, the H-bridge AC signal generating circuit includes two H-bridge circuits.

[0012] As a preferred solution of the utility model, one H-bridge circuit includes a first triode, a second triode, a fifth triode, a sixth triode, a seventh triode, and an eighth triode; the collectors of the first triode, the second triode, the fifth triode, and the seventh triode are all electrically connected to the voltage output end of the in-phase amplifier circuit; the bases of the first triode and the sixth triode are all electrically connected to the collector of the fifth triode, and the bases of the second triode and the eighth triode are all electrically connected to the collector of the seventh triode; the emitters of the first triode and the sixth triode are electrically connected to one input end of one of the liquid lenses; the emitters of the second triode and the eighth triode are electrically connected to the other input end of one of the liquid lenses; the base of the fifth triode is electrically connected to the 1A PWM pulse signal output end of the main control chip, and the base of the seventh triode is electrically connected to the 2A The PWM pulse signal output terminal is electrically connected; the emitter of the fifth triode, the collector of the sixth triode, the emitter of the seventh triode, and the collector of the eighth triode are all grounded.

[0013] As a preferred solution of the utility model, the first triode, the second triode, the fifth triode and the seventh triode are NPN triodes; the sixth triode and the eighth triode are PNP triodes.

[0014] As a preferred solution of the utility model, another H-bridge circuit includes a third triode, a fourth triode, a ninth triode, a tenth triode, an eleventh triode, and a twelfth triode; the collectors of the third triode, the fourth triode, the ninth triode, and the eleventh triode are all electrically connected to the voltage output end of the in-phase amplifier circuit; the bases of the third triode and the tenth triode are all electrically connected to the collector of the ninth triode, and the bases of the fourth triode and the twelfth triode are all electrically connected to the collector of the eleventh triode; the emitters of the third triode and the tenth triode are electrically connected to an input end of another path of the liquid lens; the emitters of the fourth triode and the twelfth triode are electrically connected to another input end of another path of the liquid lens; the base of the third triode is electrically connected to the 1B PWM pulse signal output end of the main control chip, and the base of the eleventh triode is electrically connected to the 2B The PWM pulse signal output terminal is electrically connected; the emitter of the ninth triode, the collector of the tenth triode, the emitter of the eleventh triode, and the collector of the twelfth triode are all grounded.

[0015] As a preferred solution of the utility model, the third transistor, the fourth transistor, the ninth transistor and the eleventh transistor are NPN transistors; the tenth transistor and the twelfth transistor are PNP transistors.

[0016] As a preferred solution of the utility model, the in-phase amplifier circuit includes an operational amplifier and a voltage follower, the in-phase input terminal of the operational amplifier is electrically connected to the Power PWM pulse signal output terminal of the control chip, the reverse input terminal is grounded, the output terminal is electrically connected to the in-phase input terminal of the voltage follower, and the output terminal of the operational amplifier is also electrically connected to the reverse input terminal through a feedback resistor; the output terminal of the voltage follower is electrically connected to the reverse input terminal and the input terminal of the H-bridge AC signal generating circuit.

[0017] As a preferred solution of the utility model, it also includes a 3.3V DC-DC power step-down circuit that provides 3.3V for the main control chip, and the power output end of the 3.3V DC-DC power step-down circuit is electrically connected to the power input end of the main control chip.

[0018] As a preferred solution of the utility model, it also includes an 18V DC-DC power step-down circuit that provides 18V for the in-phase amplifier circuit, and the power output end of the 18V DC-DC power step-down circuit is electrically connected to the power input end of the in-phase amplifier circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the principle diagram of the electronic focusing control circuit of the liquid lens of the utility model;

[0020] Figure 2 This is a schematic diagram of the structure of stage lighting;

[0021] Figure 3 This is the circuit diagram of the main control chip;

[0022] Figure 4 3.3V DC-DC power supply step-down circuit diagram;

[0023] Figure 5 This is the circuit diagram of the same-phase amplifier;

[0024] Figure 6 This is the 18V DC-DC power supply step-down circuit diagram;

[0025] Figure 7 This is one of the H-bridge circuit diagrams;

[0026] Figure 8 This is another H-bridge circuit diagram. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] In the present utility model, it needs to be explained that if there are directional indications involved in the embodiments of the present utility model (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial...), then the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0029] This embodiment provides a liquid lens electronic focusing control circuit, such as Figure 1 - Figure 3As shown, it includes a main control chip U4, a common-phase amplifier circuit, an H-bridge AC signal generating circuit, and a liquid lens 1; the main control chip, one PWM pulse signal output end of which is electrically connected to the input end of the common-phase amplifier circuit, and the other PWM pulse signal output ends are respectively electrically connected to the PWM pulse signal input ends of the H-bridge AC signal generating circuit; the common-phase amplifier circuit, whose voltage output end is electrically connected to the voltage input end of the H-bridge AC signal generating circuit, receives different PWM pulse signals output by the main control chip to provide different voltages for the H-bridge AC signal generating circuit; the H-bridge AC signal generating circuit, whose output end is electrically connected to the input end of the liquid lens, after the PWM pulse signal input by the main control chip drives the H-bridge to work, receives different voltages provided by the common-phase amplifier circuit, generates an AC signal with variable amplitude to drive the liquid lens to produce a corresponding degree of atomization.

[0030] like Figure 2 As shown, the stage light includes a lamp body shell 3, an LED light source 2 and a liquid lens 1 arranged in the front. The main control chip generates an AC signal with a variable amplitude through PWM control of the in-phase amplifier circuit in cooperation with the H-bridge AC signal generating circuit to drive the liquid lens to produce different degrees of atomization effects. When the light beam emitted by the LED light source 2 passes through the atomized liquid lens, the beam angle will change, thereby achieving the effect of adjusting the focal length. The entire adjustment process is at the millisecond level, and because it does not require structures such as motors and the required current is very small, the noise is extremely low, and the volume and weight of the lamp body are also greatly reduced.

[0031] like Figure 3 As shown, the main control chip U4 includes a Power PWM pulse signal output terminal, a 1A PWM pulse signal output terminal, a 2A PWM pulse signal output terminal, a 1B PWM pulse signal output terminal, and a 2B PWM pulse signal output terminal; the Power PWM pulse signal output terminal is electrically connected to the input terminal of the in-phase amplifier circuit; the 1A PWM pulse signal output terminal, the 2A PWM pulse signal output terminal, the 1B PWM pulse signal output terminal, and the 2B PWM pulse signal output terminal are electrically connected to the PWM pulse signal input terminal of the H-bridge AC signal generating circuit.

[0032] like Figure 4 As shown, the 3.3V DC-DC power supply buck circuit includes a DC-DC power supply buck chip U1. The power supply is input into the DC-DC power supply buck chip U1 after filtering, and the DC-DC power supply buck chip U1 outputs a 3.3V power supply to provide a main control chip U4.

[0033] like Figure 5As shown, the in-phase amplifier circuit includes an operational amplifier U3A and a voltage follower U3B. The in-phase input terminal of the operational amplifier U3A is electrically connected to the Power PWM pulse signal output terminal of the control chip through resistors R7 and R8, and the reverse input terminal is grounded through resistor R9. The reverse input terminal is also electrically connected to the output terminal through feedback resistor R10, and the output terminal is electrically connected to the in-phase input terminal of the voltage follower U3B through resistor R11. The output terminal of the voltage follower U3B is electrically connected to the reverse input terminal and the input terminal of the H-bridge AC signal generating circuit.

[0034] like Figure 5 and Figure 6 As shown, the power input end of the operational amplifier U3A is electrically connected to an 18V DC-DC power step-down circuit. The 18V DC-DC power step-down circuit includes a DC-DC power step-down chip U2. The power is input into the DC-DC power step-down chip U2 after filtering, and the DC-DC power step-down chip U2 outputs 18V power to provide the operational amplifier U3A.

[0035] When the Power PWM pulse signal output terminal of the control chip outputs the "Power PWM" pulse signal to the R7 resistor, the operational amplifier U3A amplifies the received signal by 5.7 times. The function of the voltage follower U3B is to improve the load capacity of the output terminal and accurately copy the voltage amplified by the operational amplifier U3A to the output "CHV". When the Power PWM pulse signal output terminal of the control chip outputs 100% of the "POWER PWM" pulse signal, the Power PWM pulse signal output terminal is approximately equal to the output voltage of 3.3V. After the operational amplifier U3A and the voltage follower U3B, a voltage of about 18.8V is obtained. By changing the size of PowerPWM, the corresponding output amplitude can be 0-18.8V, which is supplied to the back-end H-bridge AC signal generating circuit.

[0036] like Figure 7 and Figure 8As shown, the H-bridge AC signal generating circuit includes two H-bridge circuits, one of which includes a first transistor Q1, a second transistor Q2, a fifth transistor Q5, a sixth transistor Q6, a seventh transistor Q7, and an eighth transistor Q8; the collectors of the first transistor, the second transistor, the fifth transistor, and the seventh transistor are all electrically connected to the voltage output end of the in-phase amplifier circuit; the bases of the first transistor and the sixth transistor are all electrically connected to the collector of the fifth transistor, and the bases of the second transistor and the eighth transistor are all electrically connected to the collector of the seventh transistor; the emitters of the first transistor and the sixth transistor are electrically connected to an input end 1A of one of the liquid lenses; the emitters of the second transistor and the eighth transistor are electrically connected to another input end 2A of one of the liquid lenses; the base of the fifth transistor is electrically connected to the 1A PWM pulse signal output end of the main control chip, and the base of the seventh transistor is electrically connected to the 2A PWM pulse signal output end of the main control chip. The PWM pulse signal output terminal is electrically connected; the emitter of the fifth triode, the collector of the sixth triode, the emitter of the seventh triode, and the collector of the eighth triode are all grounded. The first triode, the second triode, the fifth triode, and the seventh triode are NPN triodes; the sixth triode and the eighth triode are PNP triodes.

[0037] Another H-bridge circuit includes a third transistor Q3, a fourth transistor Q4, a ninth transistor Q9, a tenth transistor Q10, an eleventh transistor Q11, and a twelfth transistor Q12; the collectors of the third transistor, the fourth transistor, the ninth transistor, and the eleventh transistor are all electrically connected to the voltage output end of the in-phase amplifier circuit; the bases of the third transistor and the tenth transistor are all electrically connected to the collector of the ninth transistor, and the bases of the fourth transistor and the twelfth transistor are all electrically connected to the collector of the eleventh transistor; the emitters of the third transistor and the tenth transistor are electrically connected to an input end 1B of another path of the liquid lens; the emitters of the fourth transistor and the twelfth transistor are electrically connected to another input end 2B of another path of the liquid lens; the base of the third transistor is electrically connected to the 1B PWM pulse signal output end of the main control chip, and the base of the eleventh transistor is electrically connected to the 2B of the main control chip. The PWM pulse signal output terminal is electrically connected; the emitter of the ninth triode, the collector of the tenth triode, the emitter of the eleventh triode, and the collector of the twelfth triode are all grounded. The third triode, the fourth triode, the ninth triode, and the eleventh triode are NPN triodes; the tenth triode and the twelfth triode are PNP triodes.

[0038] Among them, 1A and 2A correspond to the first group of terminals of the liquid lens; 1B and 2B correspond to the second group of terminals of the liquid lens. The voltage signal amplified by the in-phase amplifier circuit is input to resistors R24, R25, R32, and R33 as power supply terminals, and the 1A PWM pulse signal output terminal and 2A PWM pulse signal output terminal of the main control chip U4 output high and low levels to resistors R16 and R17 respectively. When the "1A PWM pulse signal output end" outputs a low level and the "2A PWM pulse signal output end" outputs a high level, the first transistor Q1 and the eighth transistor Q8 are turned on, and "CHV" flows through the "1A" and "2A" ends of the liquid lens; when the "1A PWM pulse signal output end" outputs a high level and the "2A PWM pulse signal output end" outputs a low level, the second transistor Q2 and the sixth transistor Q6 are turned on, and "CHV" flows through the "2A" and "1A" ends of the liquid lens; in conjunction with "CHV", an AC signal with a variable amplitude can be generated. The same applies to the other group supplying the "1B" and "2B" ends of the liquid lens.

[0039] The above embodiments are only used to illustrate the detailed scheme of the utility model. The utility model is not limited to the above detailed scheme, that is, it does not mean that the utility model must rely on the above detailed scheme to be implemented. Those skilled in the art should understand that any improvement to the utility model, equivalent replacement of various raw materials of the utility model product, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the utility model.

Claims

1. A liquid lens electronic focusing control circuit, characterized in that: It includes a main control chip (U4), a common-mode amplifier circuit, an H-bridge AC signal generating circuit, and a liquid lens (1); The main control chip has one PWM pulse signal output terminal electrically connected to the input terminal of the in-phase amplifier circuit, and another PWM pulse signal output terminal electrically connected to the PWM pulse signal input terminal of the H-bridge AC signal generating circuit; The in-phase amplifier circuit has a voltage output terminal electrically connected to a voltage input terminal of an H-bridge AC signal generating circuit, and receives different PWM pulse signals output by a main control chip to provide different voltages for the H-bridge AC signal generating circuit; The H-bridge AC signal generating circuit has an output end electrically connected to the input end of the liquid lens. After the PWM pulse signal input by the main control chip drives the H-bridge circuit to work, it receives different voltages provided by the in-phase amplifier circuit to generate an AC signal with variable amplitude to drive the liquid lens to produce a corresponding degree of atomization.

2. The liquid lens electronic focusing control circuit according to claim 1, characterized in that: The main control chip includes a Power PWM pulse signal output terminal, a 1A PWM pulse signal output terminal, a 2A PWM pulse signal output terminal, a 1B PWM pulse signal output terminal, and a 2B PWM pulse signal output terminal; The power PWM pulse signal output terminal is electrically connected to the input terminal of the in-phase amplifier circuit; The 1A PWM pulse signal output terminal, the 2A PWM pulse signal output terminal, the 1B PWM pulse signal output terminal, and the 2B PWM pulse signal output terminal are electrically connected to the PWM pulse signal input terminal of the H-bridge AC signal generating circuit.

3. The liquid lens electronic focusing control circuit according to claim 2, characterized in that: The H-bridge AC signal generating circuit includes two H-bridge circuits.

4. The liquid lens electronic focusing control circuit according to claim 3, characterized in that: One of the H-bridge circuits includes a first transistor (Q1), a second transistor (Q2), a fifth transistor (Q5), a sixth transistor (Q6), a seventh transistor (Q7), and an eighth transistor (Q8); the collectors of the first transistor, the second transistor, the fifth transistor, and the seventh transistor are all electrically connected to the voltage output end of the in-phase amplifier circuit; the bases of the first transistor and the sixth transistor are all electrically connected to the collector of the fifth transistor, and the bases of the second transistor and the eighth transistor are all electrically connected to the collector of the seventh transistor; the emitters of the first transistor and the sixth transistor are electrically connected to one input end of one of the liquid lenses; the emitters of the second transistor and the eighth transistor are electrically connected to the other input end of one of the liquid lenses; the base of the fifth transistor is electrically connected to the 1APWM pulse signal output end of the main control chip, and the base of the seventh transistor is electrically connected to the 2A The PWM pulse signal output terminal is electrically connected; the emitter of the fifth triode, the collector of the sixth triode, the emitter of the seventh triode, and the collector of the eighth triode are all grounded.

5. The liquid lens electronic focusing control circuit according to claim 4, characterized in that: The first transistor, the second transistor, the fifth transistor, and the seventh transistor are NPN transistors; the sixth transistor and the eighth transistor are PNP transistors.

6. The liquid lens electronic focus control circuit according to claim 3, characterized in that: Another H-bridge circuit includes a third triode (Q3), a fourth triode (Q4), a ninth triode (Q9), a tenth triode (Q10), an eleventh triode (Q11), and a twelfth triode (Q12); the collectors of the third triode, the fourth triode, the ninth triode, and the eleventh triode are all electrically connected to the voltage output end of the in-phase amplifier circuit; the bases of the third triode and the tenth triode are all electrically connected to the collector of the ninth triode, and the bases of the fourth triode and the twelfth triode are all electrically connected to the collector of the eleventh triode; the emitters of the third triode and the tenth triode are electrically connected to an input end of another one of the liquid lenses; the emitters of the fourth triode and the twelfth triode are electrically connected to another input end of another one of the liquid lenses; the base of the third triode is electrically connected to 1B of the main control chip. The PWM pulse signal output end is electrically connected, and the base of the eleventh transistor is electrically connected to the 2BPWM pulse signal output end of the main control chip; the emitter of the ninth transistor, the collector of the tenth transistor, the emitter of the eleventh transistor, and the collector of the twelfth transistor are all grounded.

7. The liquid lens electronic focus control circuit according to claim 6, characterized in that: The third transistor, the fourth transistor, the ninth transistor and the eleventh transistor are NPN transistors; the thirteenth transistor and the twelfth transistor are PNP transistors.

8. The liquid lens electronic focus control circuit according to claim 2, characterized in that: The in-phase amplifier circuit includes an operational amplifier (U3A) and a voltage follower (U3B), wherein the in-phase input terminal of the operational amplifier is electrically connected to the PowerPWM pulse signal output terminal of the control chip, the reverse input terminal is grounded, the output terminal is electrically connected to the in-phase input terminal of the voltage follower, and the output terminal of the operational amplifier is also electrically connected to the reverse input terminal through a feedback resistor; the output terminal of the voltage follower is electrically connected to the reverse input terminal and the input terminal of the H-bridge AC signal generating circuit.

9. The liquid lens electronic focus control circuit according to claim 1, characterized in that: It also includes a 3.3V DC-DC power step-down circuit that provides 3.3V for the main control chip, and the power output end of the 3.3V DC-DC power step-down circuit is electrically connected to the power input end of the main control chip.

10. The liquid lens electronic focus control circuit according to claim 1, characterized in that: It also includes an 18V DC-DC power step-down circuit that provides 18V for the in-phase amplifier circuit. The power output end of the 18V DC-DC power step-down circuit is electrically connected to the power input end of the in-phase amplifier circuit.

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