Flashlight color temperature control circuit and control method, and flashlight device

Abstract

The present application provides a flash color temperature control circuit and control method, and a flash device. The flash color temperature control circuit includes a power supply circuit, a trigger circuit, and a control unit. The power supply circuit has a first controlled end and an electric energy output end; the electric energy output end is electrically connected to the light-emitting unit of the flash to power the light-emitting unit according to a voltage adjustment signal; the power supply circuit and the light-emitting unit are connected in series to form a power supply loop; the trigger circuit has a second controlled end and a trigger control end; the trigger control end is electrically connected to the power supply loop to adjust the flash duration of the light-emitting unit according to an on-off control signal; the control unit is electrically connected to the first controlled end and the second controlled end, and adjusts the light color temperature of the light-emitting unit by sending a voltage adjustment signal to the first controlled end and an on-off control signal to the second controlled end. The present application can improve the flexibility of adjusting the color temperature of the flash.

Description

Technical Field

[0001] The present application relates to the field of photographic equipment, and in particular to a flashlight color temperature control circuit and control method, and a flashlight device. Background Art

[0002] With the development of mobile communication technology, mobile devices are playing an increasingly important role in people's lives and work. In particular, mobile devices with camera functions, such as mobile phones, MP4 players, PDAs, and laptops, have brought great joy to people's lives. Photography requires light, and in addition to natural light, artificial light is often needed to assist. The artificial light built into mobile devices with cameras often falls short of actual usage needs, so people often use external flashes for additional photography.

[0003] However, the color temperature adjustment in an external flash generally has only a few fixed gears, which is inflexible and cannot meet the requirements for the color temperature of the external flash in diverse shooting environments.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the application and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0005] One purpose of the present application is to provide a circuit capable of controlling the color temperature of a flash lamp, so as to improve the flexibility of adjusting the color temperature of the flash lamp.

[0006] To solve the above technical problems, this application adopts the following technical solutions:

[0007] A flashlight color temperature control circuit, comprising:

[0008] A power supply circuit having a first controlled end and a power output end; the first controlled end is used to receive a voltage regulation signal; the power output end is electrically connected to the light-emitting unit of the flash lamp to power the light-emitting unit according to the voltage regulation signal; the power supply circuit and the light-emitting unit are connected in series to form a power supply loop;

[0009] a trigger circuit having a second controlled end and a trigger control end; the second controlled end is used to receive an on-off control signal, and the trigger control end is electrically connected to the power supply circuit to adjust the flash duration of the light-emitting unit according to the on-off control signal;

[0010] A control unit is electrically connected to the first controlled end and the second controlled end, and adjusts the light color temperature of the light-emitting unit by sending the voltage adjustment signal to the first controlled end and sending the on-off control signal to the second controlled end.

[0011] According to an embodiment of the present application, the control unit includes a main control circuit, and the main control circuit has a first control terminal and a second control terminal;

[0012] The first control end is electrically connected to the first controlled end, and is configured to send the voltage regulation signal to the first controlled end;

[0013] The second control end is electrically connected to the second controlled end, and is configured to send the on / off control signal to the second controlled end.

[0014] According to an embodiment of the present application, the control unit includes a first control circuit and a second control circuit;

[0015] The first control circuit is electrically connected to the first controlled end, and is configured to send the voltage regulation signal to the first controlled end;

[0016] The second control circuit is electrically connected to the second controlled end, and is configured to send the on / off control signal to the second controlled end.

[0017] According to an embodiment of the present application, the power supply circuit includes a voltage regulating circuit and an energy storage circuit connected in series;

[0018] The input end of the voltage regulating circuit is connected to a power supply, and the output end of the voltage regulating circuit is connected to the energy storage circuit; the controlled end of the voltage regulating circuit is connected to the control unit to output a specific voltage under the control of the control unit;

[0019] The energy storage circuit is connected to the light emitting unit, and the energy storage circuit stores the electric energy output by the voltage regulating circuit. The output voltage of the energy storage circuit is greater than or equal to the light emitting trigger voltage of the light emitting unit.

[0020] According to one embodiment of the present application, the voltage regulation circuit includes a forward circuit or a flyback circuit, and the forward circuit or the flyback circuit has a transformer, the primary winding of the transformer is connected to the power supply, and the secondary winding of the transformer is connected to the energy storage circuit.

[0021] According to an embodiment of the present application, the trigger circuit includes a switch circuit; a controlled end of the switch circuit is connected to the control unit, and a first end and a second end of the switch circuit are connected in series in the power supply circuit;

[0022] The control unit controls the on / off of the power supply circuit by controlling the on / off of the switch circuit.

[0023] According to an embodiment of the present application, the on-off control signal is a PWM signal, and the control unit adjusts the duty cycle of the on-off control signal to control the flash duration of the light-emitting unit.

[0024] According to an embodiment of the present application, the control unit further includes a storage circuit, which stores a correspondence between the light color temperature and control parameters; wherein the control parameters include power supply voltage information of the light emitting unit and flash duration information of the light emitting unit;

[0025] The control unit generates the voltage adjustment signal and the on-off control signal according to the correspondence between the luminous color temperature and the control parameter, and the target luminous color temperature to be achieved.

[0026] According to an embodiment of the present application, the control unit further includes a storage circuit, which stores a correspondence between the light color temperature, the flash power, and the control parameters; wherein, the control parameters include the supply voltage information of the light emitting unit and the flash duration information of the light emitting unit;

[0027] The control unit generates the voltage adjustment signal and the on-off control signal according to the correspondence between the luminous color temperature, the flash power and the control parameters, as well as the target luminous color temperature and the target flash power to be achieved.

[0028] According to another aspect of the present application, a flash device is provided, comprising a light emitting unit and a flash color temperature control circuit;

[0029] The flash color temperature control circuit is electrically connected to the light emitting unit to adjust the light color temperature of the light emitting unit.

[0030] According to another aspect of the present application, a method for controlling the color temperature of a flash lamp is provided, comprising:

[0031] Obtaining a target luminous color temperature to be achieved by the luminous unit of the flash lamp;

[0032] Determining the control parameters corresponding to the target luminous color temperature according to a preset correspondence between the luminous color temperature and the control parameters; wherein the control parameters include the power supply voltage information of the luminous unit and the flash duration information of the luminous unit;

[0033] According to the determined control parameters, the power supply voltage of the light emitting unit and the flashing duration of the light emitting unit are controlled.

[0034] According to an embodiment of the present application, the method further includes:

[0035] Obtaining a target flash power to be achieved by the light-emitting unit;

[0036] The determining of the control parameters corresponding to the target luminous color temperature according to the preset correspondence between the luminous color temperature and the control parameters includes:

[0037] According to the preset correspondence between the luminous color temperature, the flash power and the control parameters, the control parameters corresponding to the target luminous color temperature and the target flash power are determined.

[0038] According to an embodiment of the present application, the correspondence between the preset luminous color temperature, flash power, and control parameters is obtained from a color temperature control database; the color temperature control database is generated by the following method:

[0039] Controlling the light-emitting unit to emit light using a plurality of sets of specific control parameters;

[0040] For each set of control parameters, obtaining the corresponding light color temperature and flash power of the light emitting unit;

[0041] A correspondence between the control parameters and the light color temperature and flash power of the light emitting unit is established, and a plurality of sets of the correspondences are combined to generate the color temperature control database.

[0042] In this application, the control unit is electrically connected to both the first controlled terminal of the power supply circuit and the second controlled terminal of the trigger circuit. The control unit sends a voltage regulation signal to the first controlled terminal, and the power supply circuit adjusts the output voltage of the power output terminal based on the voltage regulation signal, thereby adjusting the color temperature of the flashlight's light. The control circuit sends an on / off control signal to the second controlled terminal, and the trigger circuit adjusts the flash duration of the light-emitting unit based on the on / off control signal, thereby adjusting the light color temperature of the light-emitting unit. Therefore, by adjusting both the supply voltage and the flash duration of the light-emitting voltage, the flexibility of color temperature adjustment is improved.

[0043] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above and other objects, features and advantages of the present application will become more apparent by describing in detail example embodiments thereof with reference to the attached drawings.

[0045] Figure 1 The figure is a circuit structure block diagram of a flash color temperature control circuit according to one embodiment.

[0046] Figure 2 is a circuit structure block diagram of a flash color temperature control circuit according to another embodiment.

[0047] Figure 3 The figure is a flow chart showing a method for controlling the color temperature of a flashlight according to one embodiment. DETAILED DESCRIPTION

[0048] Although the present application can be easily embodied in different forms of embodiments, only some of the specific embodiments are shown in the drawings and will be described in detail in this specification. It should be understood that this description should be regarded as an exemplary illustration of the principles of the application and is not intended to limit the application to what is described herein.

[0049] Thus, a feature indicated in this specification will be used to illustrate one of the features of one embodiment of the present application, rather than implying that each embodiment of the present application must have the described feature. In addition, it should be noted that this specification describes many features. Although certain features can be combined together to illustrate possible system designs, these features can also be used in other, not explicitly described, combinations. Thus, unless otherwise stated, the described combinations are not intended to be limiting.

[0050] In the embodiments shown in the accompanying drawings, directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of various components of the present application are not absolute but relative. These descriptions are applicable when these components are in the positions shown in the accompanying drawings. If the descriptions of the positions of these components are changed, the directional indications will also change accordingly.

[0051] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of this application will be more comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The accompanying drawings are merely schematic illustrations of the present application and are not necessarily drawn to scale. Identical reference numerals in the figures indicate identical or similar parts, and thus repeated descriptions thereof will be omitted.

[0052] The preferred embodiments of the present application are further described in detail below in conjunction with the drawings of this specification.

[0053] The present application embodiment provides a flash color temperature control circuit for adjusting the light color temperature of the flash light emitting unit 10. Figure 1 , Figure 1 The figure is a circuit structure block diagram of a flash color temperature control circuit according to one embodiment.

[0054] Here, the flash color temperature control circuit includes a power supply circuit 10, a trigger circuit 20, and a control unit 30. The power supply circuit 10 has a first controlled terminal and a power output terminal; the first controlled terminal is used to receive a voltage adjustment signal; the power output terminal is electrically connected to the light-emitting unit 10 of the flash, so as to power the light-emitting unit 10 according to the voltage adjustment signal; the power supply circuit 10 and the light-emitting unit 10 are connected in series to form a power supply loop; the trigger circuit 20 has a second controlled terminal and a trigger control terminal; the second controlled terminal is used to receive an on-off control signal, and the trigger control terminal is electrically connected to the power supply loop to adjust the flash duration of the light-emitting unit 10 according to the on-off control signal; the control unit 30 is electrically connected to both the first controlled terminal and the second controlled terminal, and adjusts the color temperature of the light-emitting unit 10 by sending a voltage adjustment signal to the first controlled terminal and an on-off control signal to the second controlled terminal.

[0055] The specific structure of the light-emitting unit 10 is not limited herein. In one embodiment, the light-emitting unit 10 includes a xenon lamp. The light-emitting unit 10 generally includes a trigger coil. Power is supplied to the light-emitting unit 10 by applying a supply voltage across the trigger coil.

[0056] In one example, the light tube of the light emitting unit 10 contains xenon gas. When the voltage loaded on the trigger coil is higher than the trigger voltage, strong electricity strikes the xenon gas in the lamp tube, causing the xenon gas to emit strong light, thereby achieving flashing of the light emitting unit 10.

[0057] The power output terminal of the power supply circuit 10 and the trigger coil of the light-emitting unit 10 form a power supply loop. When the power supply loop is turned on, the power supply voltage output by the power supply circuit 10 is applied to the light-emitting unit 10, causing the light-emitting unit 10 to emit light. The higher the power supply voltage of the light-emitting unit 10, the higher the color temperature of its light.

[0058] See also Figure 2 , Figure 2 This is a block diagram of a circuit structure of a flashlight color temperature control circuit according to another embodiment. In one embodiment, the power supply circuit 10 includes a voltage regulator circuit 11 and a tank circuit 12 connected in series. The input of the voltage regulator circuit 11 is connected to a power source, and the output of the voltage regulator circuit 11 is connected to the tank circuit 12. The controlled end of the voltage regulator circuit 11 is connected to the control unit 30 to output a specific voltage under the control of the control unit 30. The tank circuit 12 is connected to the light-emitting unit 10 and stores the electrical energy output by the voltage regulator circuit 11. The output voltage of the tank circuit 12 is greater than or equal to the trigger voltage for the light-emitting unit 10 to emit light.

[0059] The power supply can be external or a battery inside the flashlight. Depending on the power supply voltage, the voltage regulator circuit 11 can be a step-down circuit or a step-up circuit. The step-down circuit can be a buck circuit or a charge pump circuit. The step-up circuit can be a boost circuit.

[0060] In one example, the voltage regulation circuit 11 includes a forward circuit or a flyback circuit, which includes a transformer and a control switch. The primary winding of the transformer is connected to a power source, and the secondary winding of the transformer is connected to the energy storage circuit 12. The control switch is connected in series with the primary winding, and its on / off state is controlled by the control unit 30.

[0061] Taking the forward circuit as an example, the primary winding of the transformer in the positive circuit can be directly connected to an AC power source or to a DC power source via an inverter circuit. Because the light-emitting unit 10 requires a relatively high supply voltage to trigger the xenon gas to emit light, its power supply safety needs to be considered. In this embodiment, since the forward circuit utilizes a transformer to achieve voltage conversion, the transformer's isolation function provides good isolation between the input and output ends of the voltage regulator circuit 11, thereby improving the safety of the input side of the voltage regulator circuit 11 and the control circuit.

[0062] The energy storage circuit 12 may include one or more capacitors. When powered on, the energy storage unit is gradually charged, and the output voltage gradually increases. The capacitance of the energy storage circuit 12 should be set so that the output voltage of the energy storage circuit 12 is greater than or equal to the light-emitting trigger voltage of the light-emitting unit 10. That is, when this trigger voltage is reached and the power supply circuit is connected, the flashlight emits light.

[0063] The trigger circuit 20 is electrically connected to the power supply circuit. In one example, the trigger circuit 20 can be connected to the light-emitting unit 10. When the trigger circuit sends a trigger signal, a structure within the light-emitting unit 10 is activated, turning on the power supply circuit, thereby emitting light. In another example, the trigger circuit 20 includes a switching circuit; the controlled end of the switching circuit is connected to the control unit 30, and the first and second ends of the switching circuit are connected in series to the power supply circuit. The control unit 30 controls the on / off of the power supply circuit by controlling the on / off of the switching circuit.

[0064] The switching circuit can include one or more switching transistors. Multiple switching transistors can be connected in parallel or series to increase the power that can be switched. Specifically, the switching transistor can be a MOS transistor or an IGBT. Here, using an IGBT as an example, the gate of the IGBT is the controlled terminal, the base of the IGBT is the controlled terminal, the emitter is the second terminal, and the collector is the first terminal.

[0065] Therefore, when the switch circuit is off, the power supply circuit is disconnected, and the light-emitting unit 10 is turned off; when the switch circuit is on, the power supply circuit is connected, and the light-emitting unit 10 flashes. The longer the flash duration of the light-emitting unit 10, the lower the color temperature of the light emitted. The shorter the flash duration of the light-emitting unit 10, the higher the color temperature of the light emitted. The flash duration here can refer to the duration of the flash in one flash-off cycle of the light-emitting unit 10. Of course, if the flash-off cycle is too short, the human eye cannot detect the off state of the light-emitting unit 10.

[0066] Here, the on / off control signal sent by the control unit 30 may be a PWM signal. The control unit 30 adjusts the duty cycle of the on / off control signal to control the duration of the flash of the light-emitting unit 10. Here, the switch in the switching circuit can be turned on and off at a higher frequency, to a degree imperceptible to the human eye. By adjusting the on-time / duty cycle of the switch, the color temperature of the light emitted by the light-emitting unit 10 can be controlled.

[0067] The control unit 30 is electrically connected to both the first controlled terminal of the power supply circuit 10 and the second controlled terminal of the trigger circuit 20. The control unit 30 sends a voltage adjustment signal to the first controlled terminal, causing the power supply circuit 10 to adjust the output voltage at the power output terminal based on the voltage adjustment signal, thereby adjusting the color temperature of the flashlight's light. The control circuit sends an on / off control signal to the second controlled terminal, causing the trigger circuit 20 to adjust the flash duration of the light-emitting unit 10 based on the on / off control signal, thereby adjusting the light color temperature of the light-emitting unit 10. Therefore, by adjusting both the light supply voltage and the flash duration, the light color temperature adjustment range and the precision of the light color temperature adjustment are increased.

[0068] For example, when it is necessary to adjust to a certain luminous color temperature value, a coarse adjustment can be performed by adjusting the power supply voltage of the light-emitting unit 10, and then a fine adjustment can be performed by adjusting the flash duration of the light-emitting unit 10, thereby improving the fineness of the luminous color temperature adjustment.

[0069] In one embodiment, the control unit 30 includes a main control circuit, which has a first control end and a second control end; the first control end is electrically connected to the first controlled end for sending a voltage regulation signal to the first controlled end; the second control end is electrically connected to the second controlled end for sending an on / off control signal to the second controlled end.

[0070] The main control circuit can be a single-chip microcomputer, MCU, CPU, or main control board. By having a single main control circuit simultaneously control the power supply circuit 10 and the trigger circuit 20, the layout of communication lines is reduced, the coordination of the control of the power supply circuit 10 and the trigger circuit 20 is improved, and the stability of the flash color temperature adjustment process is improved.

[0071] In another embodiment, the control unit 30 includes a first control circuit and a second control circuit; the first control circuit is electrically connected to the first controlled end for sending a voltage regulation signal to the first controlled end; the second control circuit is electrically connected to the second controlled end for sending an on / off control signal to the second controlled end.

[0072] Here, the first control circuit can be a single-chip microcomputer, an MCU, or a CPU. The second control circuit can also be a single-chip microcomputer, an MCU, or a CPU. This embodiment implements independent control of the power supply circuit 10 and the trigger circuit 20. Even if the first control circuit fails, the second control circuit can still adjust the light color temperature by controlling the flash duration of the light-emitting unit 10. Alternatively, even if the second control circuit fails, the first control circuit can still adjust the light color temperature by controlling the supply voltage of the light-emitting unit 10. Therefore, this embodiment improves the reliability of the flash color temperature control.

[0073] In one embodiment, the flash color temperature control circuit also includes a storage circuit, which stores the correspondence between control parameters and luminous color temperature; wherein the control parameters include power supply voltage information of the light-emitting unit 10 and flash duration information of the light-emitting unit 10; the controller generates a voltage adjustment signal and an on-off control signal based on the correspondence between the control parameters and the luminous color temperature, as well as the target luminous color temperature to be achieved.

[0074] Here, the flash duration information of the light emitting unit 10 may specifically include the specific duration of the flash of the light emitting unit 10 , and may also include the duty cycle of the on-off control signal.

[0075] The storage circuit may include a hard disk. The correspondence between the control parameters and the luminous color temperature may be expressed in the form of a table or a curve. The correspondence between the control parameters and the luminous color temperature may be stored in the storage circuit via data line transmission or network download.

[0076] In one embodiment, the target light color temperature can be generated by the flash based on a specific algorithm according to the shooting environment, or can be set by the user. The flash can also be configured to include a human-computer interaction component, such as a button, a touch screen, a voice input component, etc., for the user to input the target light color temperature.

[0077] Once the control unit 30 obtains the target color temperature, it can retrieve the control parameters based on the preset correspondence between the control parameters and the color temperature, thereby generating a voltage adjustment signal and an on / off control signal. The power supply circuit 10 outputs a corresponding voltage based on the voltage adjustment signal, and the trigger circuit 20 controls the flash duration of the light-emitting unit 10 based on the on / off control signal, thereby ensuring that the color temperature output by the light-emitting unit 10 matches the target color temperature. This embodiment improves the accuracy of matching the target color temperature by providing a storage circuit that pre-stores the correspondence between the control parameters and the color temperature.

[0078] In another embodiment, the flash color temperature control circuit further includes a storage circuit, which stores the correspondence between the luminous color temperature, flash power and control parameters; wherein the control parameters include the power supply voltage information of the light-emitting unit 10 and the flash duration information of the light-emitting unit 10; the controller generates a voltage adjustment signal and an on-off control signal according to the correspondence between the luminous color temperature, flash power and control parameters, as well as the target luminous color temperature and target flash power to be achieved.

[0079] Specifically, the corresponding relationship between the luminous color temperature, the flash power and the control parameters can be expressed in the form of a table or a curve, or can be stored in a storage circuit by means of data line transmission or network download.

[0080] After the control unit 30 obtains the target luminous color temperature and target flash power, it retrieves the control parameters based on the preset luminous color temperature, flash power, and control parameters, thereby generating a voltage adjustment signal and an on / off control signal. The power supply circuit 10 outputs a corresponding voltage based on the voltage adjustment signal, and the trigger circuit 20 controls the flash duration of the light-emitting unit 10 based on the on / off control signal, thereby ensuring that the luminous color temperature output by the light-emitting unit 10 matches the target luminous color temperature and the flash power of the light-emitting unit 10 matches the target power. This embodiment utilizes a storage circuit that stores the correspondence between control parameters and luminous color temperature to improve the accuracy of matching the target luminous color temperature.

[0081] In this embodiment, the flash power is also controlled to further improve the accuracy of color temperature control. Flash power affects the brightness of the light emitting unit 10, so by adjusting the flash light color temperature in combination with the brightness of the light emitting unit 10, the accuracy of color temperature control can be improved.

[0082] Here, the generation process of the correspondence between the luminous color temperature, the flash power and the control parameters is taken as an example for explanation.

[0083] In one embodiment, the flash color temperature control circuit further includes a color temperature sampling circuit; the color temperature sampling circuit is used to be electrically connected to the color temperature detection device to sample the light emitting color temperature of the light emitting unit 10 detected by the color temperature detection device; the color temperature sampling circuit is electrically connected to the control unit 30.

[0084] The control unit 30 controls the power supply circuit 10 and trigger circuit 20 according to specific control parameters. Specifically, the power supply circuit 10 outputs a specific supply voltage, and the trigger circuit 20 controls the light-emitting unit 10 to flash for a specific duration. Based on the color temperature value acquired by the color temperature sampling circuit, the control unit 30 generates a correspondence between the specific control parameters and the color temperature of the light. By continuously changing the control parameters and repeating this process of determining the correspondence, a color temperature control database can be formed.

[0085] Here, the luminous color temperature detection device may be a luminous color temperature sensor.

[0086] In another embodiment, the flash color temperature control circuit further includes a power detection circuit; the power detection circuit is electrically connected to the power supply circuit 10 to detect the flash power of the light-emitting unit 10; and the control circuit is electrically connected to the power detection circuit to obtain the flash power. The power detection circuit may include a voltage detection circuit and a current detection circuit to respectively detect the voltage and current of the light-emitting unit 10.

[0087] The control unit 30 controls the power supply circuit 10 and trigger circuit 20 according to specific control parameters. Specifically, the power supply circuit 10 outputs a specific supply voltage, which controls the trigger circuit 20 to cause the light-emitting unit 10 to flash for a specific duration. Based on the color temperature value acquired by the color temperature sampling circuit and the flash power detected by the power detection circuit, the control unit 30 generates a correspondence between the specific control parameters and the color temperature and flash power of the light-emitting unit 10. By continuously changing the control parameters and repeating this process of determining the correspondence, a color temperature control database can be formed.

[0088] See also Figure 3 , Figure 3 FIG1 is a flow chart showing a method for controlling the color temperature of a flashlight according to an embodiment. In the following embodiment, an embodiment of the method for controlling the color temperature of a flashlight is described.

[0089] In one embodiment, the flashlight color temperature control method includes:

[0090] S50 , obtaining a target light color temperature to be achieved by the light emitting unit 10 of the flash lamp.

[0091] As mentioned above, the target luminous color temperature can be generated by the flash according to the shooting environment based on a specific algorithm, or it can be set by the user.

[0092] S51, determining control parameters corresponding to the target luminous color temperature according to the preset correspondence between the luminous color temperature and the control parameters; wherein the control parameters include the power supply voltage information of the luminous unit 10 and the flash duration information of the luminous unit 10.

[0093] The correspondence between the preset luminous color temperature and the control parameters is stored in the storage circuit. The power supply voltage information of the light-emitting unit 10 includes the voltage value of the power supply voltage. The flash duration information of the light-emitting unit 10 includes the specific value of the flash duration, or the ratio of the on-time to the off-time (duty cycle) during the on-off cycle of the flash.

[0094] S52 , controlling the supply voltage of the light emitting unit 10 and the flashing duration of the light emitting unit 10 according to the determined control parameters.

[0095] Once the control unit 30 obtains the target color temperature, it can retrieve the control parameters based on the preset correspondence between the control parameters and the color temperature, thereby generating a voltage adjustment signal and an on / off control signal. The power supply circuit 10 outputs a corresponding voltage based on the voltage adjustment signal, and the trigger circuit 20 controls the flash duration of the light-emitting unit 10 based on the on / off control signal, thereby ensuring that the color temperature output by the light-emitting unit 10 matches the target color temperature. This embodiment improves the accuracy of matching the target color temperature by providing a storage circuit that pre-stores the correspondence between the control parameters and the color temperature.

[0096] In another embodiment, the method further comprises:

[0097] The target flash power to be achieved by the light-emitting unit 10 is obtained.

[0098] Here, the target flash power can be calculated by a power detection circuit.

[0099] S51, determining control parameters corresponding to the target luminous color temperature based on a preset correspondence between the luminous color temperature and the control parameters; wherein the control parameters include information about the power supply voltage of the luminous unit 10 and information about the flash duration of the luminous unit 10, including:

[0100] According to the preset correspondence between the luminous color temperature, the flash power and the control parameters, the control parameters corresponding to the target luminous color temperature and the target flash power are determined.

[0101] Specifically, the corresponding relationship between the luminous color temperature, the flash power and the control parameters can be expressed in the form of a table or a curve, or can be stored in a storage circuit by means of data line transmission or network download.

[0102] Here, the luminous color temperature and control parameters under a specific flash power can be determined by searching and comparing, and then compared with the target luminous color temperature to determine the control parameters corresponding to the target luminous color temperature.

[0103] After the control unit 30 obtains the target luminous color temperature and target flash power, it retrieves the control parameters based on the preset luminous color temperature, flash power, and control parameters, thereby generating a voltage adjustment signal and an on / off control signal. The power supply circuit 10 outputs a corresponding voltage based on the voltage adjustment signal, and the trigger circuit 20 controls the flash duration of the light-emitting unit 10 based on the on / off control signal, thereby ensuring that the luminous color temperature output by the light-emitting unit 10 matches the target luminous color temperature and the flash power of the light-emitting unit 10 matches the target power. This embodiment utilizes a storage circuit that stores the correspondence between control parameters and luminous color temperature to improve the accuracy of matching the target luminous color temperature.

[0104] In this embodiment, the flash power is also set to further improve the accuracy of color temperature control. Flash power affects the brightness of the light emitting unit 10, so by adjusting the flash light color temperature in combination with the brightness of the light emitting unit 10, the accuracy of color temperature control can be improved.

[0105] In one embodiment, the correspondence between the preset luminous color temperature, flash power, and control parameters is obtained from a color temperature control database; the luminous color temperature sampling database is generated by the following method:

[0106] The light emitting unit 10 is controlled to emit light using a plurality of sets of specific control parameters.

[0107] For each set of control parameters, the light color temperature and flash power of the corresponding light emitting unit 10 are obtained;

[0108] A correspondence between the control parameters and the light color temperature and flash power of the light emitting unit 10 is established, and multiple sets of correspondences are combined to generate a color temperature control database.

[0109] Specifically, the control unit 30 controls the power supply circuit 10 and the trigger circuit 20 according to specific control parameters. Specifically, the power supply circuit 10 outputs a specific supply voltage, and the trigger circuit 20 controls the flashing of the light-emitting unit 10 to a specific duration. For example, multiple supply voltages and multiple on-off duty cycles of the switching circuits can be set. Each supply voltage and multiple on-off duty cycles form a set of control parameters. Assuming four supply voltages and four on-off duty cycles of the switching circuits are set, 16 sets of control parameters can be formed.

[0110] Specifically, for each control parameter, the light color temperature detection device detects the light color temperature of the light emitting unit 10 under the control parameter. The power detection circuit detects the flash power under the control parameter. The light color temperature data and the flash power are stored in the control unit 30.

[0111] Then, the sampled light color temperature and flash power of the light emitting unit 10 are arranged in data, and a corresponding relationship with the control parameters is established to form a color temperature control database.

[0112] In step S52, the power supply circuit 10 may be adjusted first, and then the trigger circuit 20 may be adjusted. Of course, the reverse is also possible.

[0113] In one embodiment, in order to further improve the efficiency of color temperature adjustment, this solution also includes:

[0114] Get the set lighting mode;

[0115] According to the preset correspondence between the luminous color temperature and the control parameters, the control parameters corresponding to the target luminous color temperature are determined, including:

[0116] According to the correspondence between the preset luminous mode, luminous color temperature and control parameters, the control parameters corresponding to the target luminous color temperature and the set luminous mode are determined. The control parameters include the main control object and the auxiliary control object (the control objects are the power supply circuit 10 and the trigger circuit 20). Therefore, even if the target luminous color temperature is the same, but the luminous modes are different, the control parameters finally determined are also different. One may be based on the power supply circuit 10 as the main control object (in this case, the trigger circuit 20 is not adjusted or is only adjusted a few times). The other may be based on the trigger circuit 20 as the main control object (in this case, the power supply circuit 10 is not adjusted or is only adjusted a few times).

[0117] Depending on the different models and brands of flashes, there can be multiple lighting modes, such as constant lighting mode, flashing mode, cycle lighting mode, partial lighting mode, etc.

[0118] In another embodiment, the method further comprises:

[0119] Obtaining the set light-emitting mode of the light-emitting unit 10;

[0120] According to the preset correspondence between the luminous color temperature, the flash power and the control parameters, the control parameters corresponding to the target luminous color temperature and the target flash power are determined, including:

[0121] According to the corresponding relationship among the preset lighting mode, lighting color temperature, flash power and control parameters, the control parameters corresponding to the set lighting mode and target flash power are determined.

[0122] Similarly, even if the target light color temperature and target flash power are the same, but the light emission modes are different, the final control parameters determined will also be different. One may be based on the power supply circuit 10 as the primary control object (in which case the trigger circuit 20 is not adjusted or is only adjusted a few times). The other may be based on the trigger circuit 20 as the primary control object.

[0123] According to another aspect of the present application, a flash device is provided, comprising a light-emitting unit 10 and a flash color temperature control circuit. The flash color temperature control circuit is electrically connected to the light-emitting unit 10 to adjust the color temperature of the light emitted by the light-emitting unit 10. Specific embodiments of the flash color temperature control circuit are described above.

Claims

1. A flashlight color temperature control circuit, characterized in that: include: A power supply circuit having a first controlled end and an electric energy output end; The first controlled end is used to receive a voltage regulation signal; the power output end is electrically connected to the light-emitting unit of the flash lamp to supply power to the light-emitting unit according to the voltage regulation signal; The power supply circuit is connected in series with the light-emitting unit to form a power supply loop; a trigger circuit having a second controlled end and a trigger control end; the second controlled end is used to receive an on-off control signal, and the trigger control end is electrically connected to the power supply circuit to adjust the flash duration of the light-emitting unit according to the on-off control signal; a control unit, electrically connected to the first controlled end and the second controlled end, for adjusting the light color temperature of the light emitting unit by sending the voltage adjustment signal to the first controlled end and sending the on / off control signal to the second controlled end; a color temperature sampling circuit, the color temperature sampling circuit being electrically connected to a color temperature detection device to sample the color temperature of the light emitting unit detected by the color temperature detection device; the color temperature sampling circuit being electrically connected to the control unit; A storage circuit storing a correspondence between luminous color temperature and control parameters; wherein the control parameters include power supply voltage information of the light-emitting unit and flash duration information of the light-emitting unit; The control unit is used for: According to the set control parameters, the power supply circuit is controlled to output a set supply voltage, and the trigger circuit controls the flash of the light-emitting unit to last for a set duration; Generating a correspondence between the set control parameter and the luminous color temperature according to the color temperature value obtained by the color temperature sampling circuit, continuously changing and setting the control parameter, and cyclically generating the correspondence between the set control parameter and the luminous color temperature to obtain the correspondence between the luminous color temperature and the control parameter; The voltage adjustment signal and the on-off control signal are generated according to the corresponding relationship between the luminous color temperature and the control parameter, as well as the target luminous color temperature to be achieved.

2. The flash color temperature control circuit according to claim 1, wherein: The control unit includes a main control circuit having a first control terminal and a second control terminal; The first control end is electrically connected to the first controlled end, and is configured to send the voltage regulation signal to the first controlled end; The second control end is electrically connected to the second controlled end, and is configured to send the on / off control signal to the second controlled end.

3. The flash color temperature control circuit according to claim 1, wherein: The control unit includes a first control circuit and a second control circuit; The first control circuit is electrically connected to the first controlled end, and is configured to send the voltage regulation signal to the first controlled end; The second control circuit is electrically connected to the second controlled end, and is configured to send the on / off control signal to the second controlled end.

4. The flash color temperature control circuit according to claim 1, wherein: The power supply circuit includes a voltage regulating circuit and an energy storage circuit connected in series; The input end of the voltage regulating circuit is connected to a power supply, and the output end of the voltage regulating circuit is connected to the energy storage circuit; the controlled end of the voltage regulating circuit is connected to the control unit to output a specific voltage under the control of the control unit; The energy storage circuit is connected to the light emitting unit, and the energy storage circuit stores the electric energy output by the voltage regulating circuit. The output voltage of the energy storage circuit is greater than or equal to the light emitting trigger voltage of the light emitting unit.

5. The flash color temperature control circuit according to claim 4, characterized in that: The voltage regulating circuit includes a forward circuit or a flyback circuit, wherein the forward circuit or the flyback circuit has a transformer, the primary winding of the transformer is connected to the power supply, and the secondary winding of the transformer is connected to the energy storage circuit.

6. The flash color temperature control circuit according to claim 1, wherein: The trigger circuit includes a switch circuit; a controlled end of the switch circuit is connected to the control unit, and a first end and a second end of the switch circuit are connected in series in the power supply circuit; The control unit controls the on / off of the power supply circuit by controlling the on / off of the switch circuit.

7. The flash color temperature control circuit according to claim 1, wherein: The on-off control signal is a PWM signal, and the control unit adjusts the duty cycle of the on-off control signal to control the flash duration of the light-emitting unit.

8. The flash color temperature control circuit according to any one of claims 1 to 7, characterized in that: The control unit further includes a storage circuit, which stores the corresponding relationship between the luminous color temperature, the flash power and the control parameters; Wherein, the control parameters include the power supply voltage information of the light emitting unit and the flash duration information of the light emitting unit; The control unit generates the voltage adjustment signal and the on-off control signal according to the correspondence between the luminous color temperature, the flash power and the control parameters, as well as the target luminous color temperature and the target flash power to be achieved.

9. A flash device, characterized in that: A light emitting unit and a flash color temperature control circuit according to any one of claims 1 to 8; The flash color temperature control circuit is electrically connected to the light emitting unit to adjust the light color temperature of the light emitting unit.

10. A method for controlling the color temperature of a flash lamp, applied to the color temperature control circuit of a flash lamp according to any one of claims 1 to 8, characterized in that: include: Obtaining a target luminous color temperature to be achieved by the luminous unit of the flash lamp; Determining the control parameters corresponding to the target luminous color temperature according to a preset correspondence between the luminous color temperature and the control parameters; wherein the control parameters include the power supply voltage information of the luminous unit and the flash duration information of the luminous unit; According to the determined control parameters, the power supply voltage of the light emitting unit and the flashing duration of the light emitting unit are controlled.

11. The method according to claim 10, characterized in that The method further comprises: Obtaining a target flash power to be achieved by the light-emitting unit; The determining of the control parameters corresponding to the target luminous color temperature according to the preset correspondence between the luminous color temperature and the control parameters includes: According to the preset correspondence between the luminous color temperature, the flash power and the control parameters, the control parameters corresponding to the target luminous color temperature and the target flash power are determined.

12. The method according to claim 11, characterized in that The correspondence between the preset luminous color temperature, flash power and control parameters is obtained from a color temperature control database; the color temperature control database is generated by the following method: Controlling the light-emitting unit to emit light using a plurality of sets of specific control parameters; For each set of control parameters, obtaining the corresponding light color temperature and flash power of the light emitting unit; A correspondence between the control parameters and the light color temperature and flash power of the light emitting unit is established, and a plurality of sets of the correspondences are combined to generate the color temperature control database.

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