Multicolor light mixing circuit applied to LED light source flash lamp, photographing camera and video camera

Abstract

The multi-color light mixing circuit comprises a red light emitting diode light source group, a green light emitting diode light source group, a blue light emitting diode light source group, an energy storage capacitor, a red light NMOS (N-channel Metal Oxide Semiconductor) switching tube, a green light NMOS switching tube, a blue light NMOS switching tube, a red light fly-wheel diode, a green light fly-wheel diode, a blue light fly-wheel diode and a red light choke inductor, and a green light choke inductor and a blue light choke inductor. A three-path simultaneous flashing mode is adopted, in the shutter time of camera exposure, three light sources emit light at the same time, and the amplitude of current flowing through each light source group is adjusted by changing the PWM duty ratio of each branch, so that different light mixing effects are achieved; when the camera is not used for photographing, the camera does not emit light, and flashes for extremely short exposure time when the shutter is pressed, thereby achieving a light supplementing effect. Through the LED flash lamp with the ultra-small size, the photographing effect of the LED normally-on lamp with the power of 50-100 times of the larger size is achieved, the portability is extremely high, and meanwhile the cost of photographing equipment is obviously reduced.

Description

Technical Field

[0001] The utility model relates to the field of power electronics, in particular to a multi-color light mixing circuit applied to an LED light source flash lamp, a camera and a video camera. Background Art

[0002] At present, LED light source lighting has become the mainstream lighting choice, especially RGB (red, green and blue) three-primary color LED lights have been widely used in landscape lighting and photography fill lighting.

[0003] In the process of realizing the multi-color light mixing circuit of the embodiment of the utility model, the inventor of this patent found that at least the conventional RGB lighting lamps on the market have the following technical disadvantages in the application of film and television photography:

[0004] The first disadvantage: Most RGB lamps use RGB complementary light mixing, which means that R, G, and B light sources emit light alternately in a switching cycle. When using a camera to shoot at high speed, the camera only exposes part of the RGB light-emitting period. The RGB three primary colors of light do not emit light at the same time, and the camera cannot actually capture the ideal mixed light effect.

[0005] The second disadvantage: ordinary small and medium power RGB lamps cannot achieve the fill light effect when using a camera's high-speed shooting. If you choose conventional RGB lamps that increase the power by 50-100 times, the cost of the fill light equipment will increase. The ultra-high power lamps will always be on, causing discomfort and damage to the eyes of the photographer, and will also require more electricity fees. It is neither economical nor environmentally friendly, and is not suitable for outdoor shooting.

[0006] In summary, existing flash lamps cannot meet actual usage requirements. Utility Model Content

[0007] The embodiments of the utility model provide a multi-color light mixing circuit applied to an LED light source flash lamp, a camera and a video camera, which solve the problem that the existing flash lamp cannot meet the actual use requirements.

[0008] On the one hand, an embodiment of the utility model provides a multi-color mixing circuit applied to an LED light source flash, comprising: a red light emitting diode light source group; a green light emitting diode light source group; a blue light emitting diode light source group; an energy storage capacitor, one end of which is electrically connected to the input ends of the red light emitting diode light source group, the green light emitting diode light source group and the blue light emitting diode light source group, and the other end is grounded; a red light NMOS switch tube, a gate electrically connected to a PWM-R red light control signal, and a source electrode is grounded; a green light NMOS switch tube, a gate electrically connected to a PWM-G green light control signal, and a source electrode is grounded; a blue light NMOS switch tube, a gate electrically connected to a PWM-B blue light control signal, and a source electrode is grounded; a red light freewheeling diode, an input end of which is electrically connected to the drain of the red light NMOS switch tube, and an output end of which is electrically connected to the input end of the red light emitting diode light source group; a green light freewheeling diode, an output end of which is electrically connected to the drain of the red light NMOS switch tube The input end is electrically connected to the drain of the green light NMOS switch tube, and the output end is electrically connected to the input end of the green light LED light source group; the blue light freewheeling diode, the input end is electrically connected to the drain of the blue light NMOS switch tube, and the output end is electrically connected to the input end of the blue light LED light source group; the red light choke inductor, one end of which is electrically connected to the output end of the red light LED light source group, and the other end is electrically connected to the input end of the red light freewheeling diode and the drain of the red light NMOS switch tube; the green light choke inductor, one end of which is electrically connected to the output end of the green light LED light source group, and the other end is electrically connected to the input end of the green light freewheeling diode and the drain of the green light NMOS switch tube; the blue light choke inductor, one end of which is electrically connected to the output end of the blue light LED light source group, and the other end is electrically connected to the input end of the blue light freewheeling diode and the drain of the blue light NMOS switch tube.

[0009] Optionally, the current amplitude of the red light emitting diode light source group, the current amplitude of the green light emitting diode light source group and the current amplitude of the blue light emitting diode light source group are the same.

[0010] Optionally, the current amplitude of the red light emitting diode light source group, the current amplitude of the green light emitting diode light source group and the current amplitude of the blue light emitting diode light source group are different.

[0011] Optionally, the number of the red light emitting diode light source groups, the number of the green light emitting diode light source groups and the number of the blue light emitting diode light source groups are the same.

[0012] Optionally, the number of the red LED light source groups, the number of the green LED light source groups, and the number of the blue LED light source groups are different.

[0013] Optionally, the number of light sources in the red LED light source group, the number of light sources in the green LED light source group, and the number of light sources in the blue LED light source group are the same.

[0014] Optionally, the number of light sources in the red LED light source group, the number of light sources in the green LED light source group, and the number of light sources in the blue LED light source group are different.

[0015] Optionally, the number of light sources in the red LED light source group, the number of light sources in the green LED light source group, and the number of light sources in the blue LED light source group are 2 or more.

[0016] On the other hand, an embodiment of the utility model further provides a camera, comprising: the multi-color light mixing circuit described in the above embodiment; and a camera body electrically connected to the multi-color light mixing circuit.

[0017] In a third aspect, an embodiment of the utility model further provides a camera, comprising: the multi-color light mixing circuit described in the aforementioned embodiment; and a photographic subject electrically connected to the multi-color light mixing circuit.

[0018] One or more technical solutions provided in the embodiments of the present utility model have at least the following technical effects or advantages:

[0019] The utility model mainly realizes the flash output of red, green and blue RGB three primary colors mixed light of the LED light source flash lamp, and realizes the RGB mixed light photography technology with high optical quality.

[0020] First, most traditional RGB lamps use the RGB complementary on-off method. During the short shutter time of the camera's high-speed shooting, the camera can only capture a certain color of light, and the photo effect does not meet the expected mixed light requirements. Compared with traditional RGB lamps, this patented circuit uses a three-way simultaneous flash method, that is, during the camera's shutter time, the three RGB color LEDs emit light at the same time, and by changing the PWM duty cycle of each branch to adjust the current amplitude flowing through each LED light source group to achieve different mixed light effects.

[0021] Second, under normal lighting comfort conditions, only small and medium-power traditional RGB lamps can be used for lighting. However, when using a camera to take photos at high speed, traditional RGB lighting fixtures cannot achieve the ideal fill-in light effect. Compared with small and medium-power traditional RGB lamps, this patented circuit does not emit light when not taking photos. The staff will not be exposed to strong light for a long time. It will flash for an extremely short exposure time when the shutter is pressed to achieve the fill-in light effect. Compared with traditional LED constant-on lights, the ultra-small LED flash can achieve the photo-taking effect of a larger LED constant-on light with 50-100 times the power. It is highly portable and significantly reduces the cost of photographic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is a structural diagram of a multi-color light mixing circuit applied to an LED light source flash lamp in one embodiment of the utility model;

[0023] Figure 2 for Figure 1 The current waveform diagram of the RGB light emitting diode light source group corresponding to the different duty cycle driving signals of PWM-R, PWM-G and PWM-B in the multi-color light mixing circuit;

[0024] In the figure:

[0025] LED-R—red light emitting diode light source group;

[0026] LED-G—Green light emitting diode light source group;

[0027] LED-B—blue light emitting diode light source group;

[0028] D1-R—Red freewheeling diode;

[0029] D2-G—green freewheeling diode;

[0030] D3-B—blue freewheeling diode;

[0031] L1-R—red light choke inductor;

[0032] L2-G—Green choke inductor;

[0033] L3-B—Blue light choke inductor;

[0034] Q1-R—red light NMOS switch tube;

[0035] Q2-G—Green light NMOS switch tube;

[0036] Q3-B—Blue light NMOS switch tube;

[0037] EC1—Energy storage capacitor. DETAILED DESCRIPTION

[0038] The embodiments of the utility model provide a multi-color light mixing circuit applied to an LED light source flash lamp, a camera and a video camera, which solve the problem that the existing flash lamp cannot meet the actual use requirements.

[0039] First, the terms that appear in the specification will be explained respectively.

[0040] 1. PWM

[0041] PWM (Pulse Width Modulation) is a method of digitally encoding analog signal levels. Through the use of high-resolution counters, the duty cycle of a square wave is modulated to encode the level of a specific analog signal. The PWM signal is still digital because at any given moment, the full-amplitude DC power supply is either fully present (ON) or completely absent (OFF). The voltage or current source is applied to the analog load in a repetitive sequence of pulses that are either on (ON) or off (OFF). The on time is when the DC power supply is applied to the load, and the off time is when the power supply is disconnected.

[0042] The main features of PWM pulses include:

[0043] Duty cycle: In a PWM cycle, the ratio of the time that the pulse is at a high level (pulse width) to the entire cycle time is called the duty cycle. The size of the duty cycle determines the average voltage or current level of the PWM signal.

[0044] Frequency: The frequency of a PWM signal is the inverse of its period. It determines how fast the PWM signal changes.

[0045] Resolution: The resolution of PWM depends on the number of bits in the counter or register used to control the pulse width. The more bits there are, the higher the resolution and the higher the simulation accuracy that can be achieved.

[0046] The PWM signal of this patent is divided into three paths. The first path is used to generate a red light control signal, represented by the symbol PWM-R; the second path is used to generate a green light control signal, represented by the symbol PWM-G; the third path is used to generate a blue light control signal, represented by the symbol PWM-B.

[0047] 2. LED

[0048] LED (Light Emitting Diode) is a solid-state semiconductor device that can convert electrical energy into visible light and can directly convert electricity into light.

[0049] The RGB LED light source groups of this patent include three types. The first type is a red LED light source group, represented by the symbol LED-R; the second type is a green LED light source group, represented by the symbol LED-G; and the third type is a blue LED light source group, represented by the symbol LED-B.

[0050] 3. MCU

[0051] MCU (Microcontroller Unit), also known as a single-chip microcomputer or single-chip microcomputer, is an integrated circuit chip that contains peripheral devices such as a processor, memory, timer, and input / output ports.

[0052] 4. RGB

[0053] RGB is a color model that obtains a variety of colors by changing the three color channels of red, green, and blue and superimposing them on each other. This standard covers almost all colors that can be perceived by human vision and is one of the most widely used color systems.

[0054] This patent uses light-emitting diodes as light sources, and according to the RGB classification, the red light, green light and blue light emitted by the light-emitting diodes are represented by R, G and B respectively. R represents red light, G represents green light, and B represents blue light.

[0055] In order to better understand the above multi-color light mixing circuit, the above multi-color light mixing circuit will be described in detail below in conjunction with the drawings and specific implementation methods of the specification. Obviously, the embodiments described in the present utility model are part of the embodiments of the present utility model, not all of the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present utility model.

[0056] 1. Structure of multi-color mixing circuit

[0057] Please refer to Figure 1 The utility model is a multi-color light mixing circuit applied to an LED light source flash lamp, comprising:

[0058] Red light emitting diode light source group LED-R;

[0059] Green light emitting diode light source group LED-G;

[0060] Blue light emitting diode light source group LED-B;

[0061] The energy storage capacitor EC1 has one end electrically connected to the input ends of the red light emitting diode light source group LED-R, the green light emitting diode light source group LED-G and the blue light emitting diode light source group LED-B, and the other end is grounded;

[0062] The red light NMOS switch tube Q1-R has a gate electrically connected to the PWM-R red light control signal and a source grounded;

[0063] Green light NMOS switch tube Q2-G, the gate is electrically connected to the PWM-G green light control signal, and the source is grounded;

[0064] A blue light NMOS switch tube Q3-B, the gate of which is electrically connected to the PWM-B blue light control signal, and the source of which is grounded;

[0065] A red freewheeling diode D1-R, whose input end is electrically connected to the drain of the red NMOS switch tube Q1-R, and whose output end is electrically connected to the input end of the red light emitting diode light source group LED-R;

[0066] A green freewheeling diode D2-G, whose input end is electrically connected to the drain of the green NMOS switch tube Q2-G, and whose output end is electrically connected to the input end of the green light emitting diode light source group LED-G;

[0067] A blue light freewheeling diode D3-B, whose input end is electrically connected to the drain of the blue light NMOS switch tube Q3-G, and whose output end is electrically connected to the input end of the blue light emitting diode light source group LED-B;

[0068] A red light choke inductor L1-R, one end of which is electrically connected to the output end of the red light emitting diode light source group LED-R, and the other end of which is electrically connected to the input end of the red light freewheeling diode D1-R and the drain of the red light NMOS switch tube Q1-R;

[0069] A green light choke inductor L2-G, one end of which is electrically connected to the output end of the green light emitting diode light source group LED-G, and the other end of which is electrically connected to the input end of the green light freewheeling diode D2-G and the drain of the green light NMOS switch tube Q2-G;

[0070] The blue light choke inductor L3-B has one end electrically connected to the output end of the blue light emitting diode light source group LED-B, and the other end electrically connected to the input end of the blue light freewheeling diode D3-B and the drain of the blue light NMOS switch tube Q3-B.

[0071] Among them, the current amplitude of the red light emitting diode light source group, the current amplitude of the green light emitting diode light source group and the current amplitude of the blue light emitting diode light source group are the same. In a specific application, according to actual needs, the current amplitude of the red light emitting diode light source group, the current amplitude of the green light emitting diode light source group and the corresponding current amplitude in the blue light emitting diode light source group can be adjusted to be the same to achieve the target color mixing effect.

[0072] The current amplitude of the red light emitting diode light source group, the current amplitude of the green light emitting diode light source group and the current amplitude of the blue light emitting diode light source group are different. In a specific application, the current amplitude of the red light emitting diode light source group, the current amplitude of the green light emitting diode light source group and the current amplitude of the blue light emitting diode light source group can be adjusted according to actual needs to change the ratio of the luminous energy of the three light sources to achieve a color mixing effect in a target range.

[0073] The number of red LED light source groups, the number of green LED light source groups, and the number of blue LED light source groups are the same. In specific applications, the number of red LED light source groups, the number of green LED light source groups, and the number of blue LED light source groups can be set to be the same according to actual needs. For example, the number of red LED light source groups, the number of green LED light source groups, and the number of blue LED light source groups are all 1, and for another example, the number of red LED light source groups, the number of green LED light source groups, and the number of blue LED light source groups are all 2, so as to achieve the target color mixing effect.

[0074] The number of red LED light source groups, the number of green LED light source groups, and the number of blue LED light source groups are different. In specific applications, the number of red LED light source groups, the number of green LED light source groups, and the number of blue LED light source groups can be set to be different according to actual needs. For example, the number of red LED light source groups is 1, the number of green LED light source groups is 2, and the number of blue LED light source groups is 3, so as to change the ratio of the luminous energy of the three light sources to achieve the color mixing effect in the target range.

[0075] The number of light sources in the red LED light source group, the number of light sources in the green LED light source group, and the number of light sources in the blue LED light source group are the same. In specific applications, the number of light sources in the red LED light source group, the number of light sources in the green LED light source group, and the corresponding number of light sources in the blue LED light source group can be set to be the same according to actual needs. For example, the number of light sources in the red LED light source group, the green LED light source group, and the blue LED light source group are all 1, and for another example, the number of light sources in the red LED light source group, the green LED light source group, and the blue LED light source group are all 2, so as to achieve the color mixing effect in the target range.

[0076] The number of light sources in the red LED light source group, the number of light sources in the green LED light source group, and the number of light sources in the blue LED light source group are different. In a specific application, the number of light sources in the red LED light source group, the number of light sources in the green LED light source group, and the number of light sources in the blue LED light source group can be set to be different according to actual needs. For example, the number of light sources in the red LED light source group is 3, the number of light sources in the green LED light source group is 2, and the number of light sources in the blue LED light source group is 1, so as to change the ratio of the luminous energy of the three light sources to achieve the color mixing effect in the target range.

[0077] The number of light sources in the red LED light source group, the number of light sources in the green LED light source group, and the number of light sources in the blue LED light source group are 2 or more. In specific applications, the number of light sources in the red LED light source group, the number of light sources in the green LED light source group, and the number of light sources in the blue LED light source group can be adjusted according to actual needs, for example, the number of light sources in the red LED light source group is 3, the number of light sources in the green LED light source group is 2, and the number of light sources in the blue LED light source group is 2, so as to achieve a color mixing effect in a target range.

[0078] 2. The role of electronic components in multi-color mixing circuits

[0079] First, the energy storage capacitor EC1 provides luminous energy to the red light emitting diode light source group LED-R, the green light emitting diode light source group LED-G, and the blue light emitting diode light source group LED-B respectively;

[0080] Second, the red light source group control module circuit:

[0081] Red light emitting diode light source group LED-R, red light emitting element, light source capable of withstanding large pulse current;

[0082] The red light choke inductor L1-R has the following functions: first, it limits the current through the red light emitting diode light source group LED-R to ensure that the red light emitting diode light source group LED-R will not be burned out by overcurrent; second, it stabilizes the current of the red light emitting diode light source group LED-R when a single working red light control signal PWM-R pulse group is in operation, so as to emit a stable red light;

[0083] The red light NMOS switch tube Q1-R controls the on-time and off-time of the red light emitting diode light source group LED-R and the red light high level open branch to GND (i.e., grounding), so as to adjust the current value of the red light emitting diode light source group LED-R and the red light high level open branch;

[0084] Red light freewheeling diode D1-R, when the red light NMOS switch tube Q1-R is turned off, the red light choke inductor current L1-R cannot change suddenly, and flows through the red light freewheeling diode D1-R to the red light emitting diode light source group LED-R to form a discharge circuit.

[0085] Third, the green light source group control module circuit:

[0086] Green light emitting diode light source group LED-G, green light emitting element, light source with the ability to withstand large pulse current;

[0087] The green light choke inductor L2-G has the following functions: first, it limits the current through the green light emitting diode light source group LED-G to ensure that the green light emitting diode light source group LED-G will not be burned out by overcurrent; second, it stabilizes the current of the green light emitting diode light source group LED-G when a single working green light control signal PWM-G pulse group is in operation, so as to emit a stable green light;

[0088] The green NMOS switch tube Q2-G controls the on-time and off-time of the green light emitting diode light source group LED-G and the green light high level open branch to GND (i.e., grounding), so as to adjust the current value of the green light emitting diode light source group LED-G and the green light high level open branch;

[0089] Green freewheeling diode D2-G, when the green NMOS switch tube Q2-G is turned off, the current of the green choke inductor L2-G cannot change suddenly, and flows through the green freewheeling diode D2-G to the green light emitting diode light source group LED-G to form a discharge loop.

[0090] Fourth, blue light source group control module circuit:

[0091] Blue light emitting diode light source group LED-B, blue light emitting element, light source with the ability to withstand large pulse current;

[0092] The blue light choke inductor L3-B has the following functions: first, it limits the current passing through the blue light emitting diode light source group LED-B to ensure that the blue light emitting diode light source group LED-B will not be burned out by overcurrent; second, it stabilizes the current of the blue light emitting diode light source group LED-B when a single working blue light control signal PWM-B pulse group is in operation, so as to emit a stable blue light;

[0093] The blue light NMOS switch tube Q3-B controls the on-time and off-time of the blue light emitting diode light source group LED-B and the blue light high level open branch to GND (i.e., grounding), so as to adjust the current value of the blue light emitting diode light source group LED-B and the blue light high level open branch;

[0094] Blue light freewheeling diode D3-B, when the blue light NMOS switch tube Q3-B is turned off, the current of the blue light choke inductor L3-B cannot change suddenly, and flows through the blue light freewheeling diode D3-B to the blue light emitting diode light source group LED-B to form a discharge circuit.

[0095] It should be noted that the multi-color mixing circuit based on the LED light source flash lamp has a red light high-level open branch, a red light low-level closed branch, a green light high-level open branch, a green light low-level closed branch, a blue light high-level open branch, and a blue light low-level closed branch.

[0096] The red light high level turn-on branch refers to the route through which the current flows when the red light control signal PWM-R is high level and the red light NMOS switch tube Q1-R is turned on. In the red light high level turn-on branch, the current passes through the energy storage capacitor EC1, the red light emitting diode light source group LED-R, the red light choke inductor L1-R, and the red light NMOS switch tube Q1-R in sequence.

[0097] The red light low level off branch refers to the discharge circuit through which the current flows when the red light control signal PWM-R is low level and the red light NMOS switch tube Q1-R is off. In the red light low level off branch, the current passes through the red light emitting diode light source group LED-R, the red light choke inductor L1-R, and the red light freewheeling diode D1-R in sequence.

[0098] The green light high level turn-on branch refers to the route through which the current flows when the green light control signal PWM-G is high level and the green light NMOS switch tube Q2-G is turned on. In the green light high level turn-on branch, the current passes through the energy storage capacitor EC1, the green light light emitting diode light source group LED-G, the green light choke inductor L2-G, and the green light NMOS switch tube Q2-G in sequence.

[0099] The green light low level off branch refers to the discharge circuit through which the current flows when the green light control signal PWM-G is low level and the green light NMOS switch tube Q2-G is turned off. In the green light low level off branch, the current passes through the green light light emitting diode light source group LED-G, the green light choke inductor L2-G, and the green light freewheeling diode D2-G in sequence.

[0100] The blue light high level turn-on branch refers to the route through which the current flows when the blue light control signal PWM-B is high level and the blue light NMOS switch tube Q3-B is turned on. In the blue light high level turn-on branch, the current passes through the energy storage capacitor EC1, the blue light emitting diode light source group LED-B, the blue light choke inductor L3-B, and the blue light NMOS switch tube Q3-B in sequence.

[0101] The blue light low level off branch refers to the discharge circuit through which the current flows when the blue light control signal PBM-B is low level and the blue light NMOS switch tube Q3-B is turned off. In the blue light low level off branch, the current passes through the blue light emitting diode light source group LED-B, the blue light choke inductor L3-B, and the blue light freewheeling diode D3-B in sequence.

[0102] (III) Working conditions of multi-color mixing circuit

[0103] like Figure 2 As shown, the R red light duty cycle of the pulse group of the red light control signal PWM-R is the largest, and the current IR passing through the red light high level opening branch and the red light low level closing branch has the largest current amplitude.

[0104] The green light duty cycle of the pulse group of the green light control signal PWM-G is in the middle, and the current amplitude of the current IG passing through the green light high level opening branch and the green light low level closing branch is in the middle.

[0105] The B blue light duty cycle of the pulse group of the blue light control signal PWM-B is the smallest, and the current IB passing through the blue light high level opening branch and the blue light low level closing branch has the smallest current amplitude.

[0106] 1) Before the control circuit gives a light-emitting signal:

[0107] The red light control signal PWM-R, the green light control signal PWM-G and the blue light control signal PWM-B remain at a low level; the three groups of light sources do not emit light;

[0108] The energy storage capacitor EC1 is charged by the charging power supply and maintained at a set voltage value.

[0109] 2) When the MCU control circuit simultaneously sends out pulse group control signals of the same duration for the red light control signal PWM-R, the green light control signal PWM-G and the blue light control signal PWM-B but with different duty ratios:

[0110] A) The principle of current regulation by the red light control signal PWM-R, green light control signal PWM-G and blue light control signal PWM-B of each branch is described as follows:

[0111] a) When the red light control signal PWM-R is at high level (PWM-RH):

[0112] The red light NMOS switch tube Q1-R is turned on, and the energy storage capacitor EC1 discharges through the red light emitting diode light source group LED-R, the red light choke inductor L1-R, and the red light NMOS switch tube Q1-R. The current of the red light emitting diode light source group LED-R rises linearly, wherein the red light choke inductor L1-R determines the rising slope.

[0113] b) When the red light control signal PWM-R is at low level (PWM-RL):

[0114] The red light NMOS switch tube Q1-R is turned off, and the current of the red light choke inductor L1-R cannot suddenly drop to zero. Instead, it turns to the red light freewheeling diode D1-R to the red light emitting diode light source group LED-R to form a discharge loop, and the current of the red light emitting diode light source group LED-R decreases linearly.

[0115] c) Red light control signal PWM-R duty cycle adjustment result:

[0116] When the duty cycle is increased, the time ratio of the high level PWM-RH of the red light control signal to the low level PWM-RL of the red light control signal increases, the current rise ratio of the red light choke inductor L1-R increases, and the overall current is larger, achieving the effect of increasing the current, which is manifested as an increase in the flash energy;

[0117] When the duty cycle is adjusted to a small value, the time ratio of the high level PWM-RH red light control signal to the low level PWM-RL red light control signal is reduced, the current drop ratio of the red light choke inductor L1-R increases, and the overall current is small, achieving the effect of reducing the current, which is manifested as a reduction in flash energy.

[0118] Since the red light source group control module circuit of the red light control signal PWM-R, the green light source group control module circuit of the green light control signal PWM-G, and the blue light source group control module circuit of the blue light control signal PWM-B have similar current regulation principles, for the sake of brevity of the specification, the specification takes the red light source group control module circuit of the red light control signal PWM-R as an example to describe the current regulation principle, and does not repeat the current regulation principle of the green light source group control module circuit of the green light control signal PWM-G and the blue light source group control module circuit of the blue light control signal PWM-B.

[0119] B) By changing the duty ratio of the red light control signal PWM-R, the green light control signal PWM-G and the blue light control signal PWM-B, the luminous energy of the red light emitting diode light source group, the green light emitting diode light source group and the blue light emitting diode light source group can be controlled respectively, and the three PWM signals are emitted and cut off at the same time, and the two different proportions of light are mixed together to form a mixed light effect of various colors.

[0120] The embodiment of the utility model further provides a camera, comprising: the multi-color light mixing circuit of the aforementioned embodiment; and a camera body electrically connected to the multi-color light mixing circuit.

[0121] The embodiment of the utility model further provides a camera, comprising: the multi-color light mixing circuit of the aforementioned embodiment; and a photographic subject electrically connected to the multi-color light mixing circuit.

[0122] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A multi-color light mixing circuit applied to an LED light source flash lamp, characterized in that: include: Red light emitting diode light source group; Green light emitting diode light source group; Blue light emitting diode light source group; an energy storage capacitor, one end of which is electrically connected to the input ends of the red light emitting diode light source group, the green light emitting diode light source group and the blue light emitting diode light source group, and the other end of which is grounded; The red light NMOS switch tube has a gate electrically connected to the PWM-R red light control signal and a source grounded; A green light NMOS switch tube, the gate of which is electrically connected to the PWM-G green light control signal, and the source of which is grounded; A blue light NMOS switch tube, the gate of which is electrically connected to the PWM-B blue light control signal, and the source of which is grounded; A red freewheeling diode, an input end of which is electrically connected to the drain of the red NMOS switch tube, and an output end of which is electrically connected to the input end of the red light emitting diode light source group; A green freewheeling diode, whose input end is electrically connected to the drain of the green NMOS switch tube, and whose output end is electrically connected to the input end of the green light emitting diode light source group; A blue light freewheeling diode, whose input end is electrically connected to the drain of the blue light NMOS switch tube, and whose output end is electrically connected to the input end of the blue light emitting diode light source group; A red light choke inductor, one end of which is electrically connected to the output end of the red light emitting diode light source group, and the other end of which is electrically connected to the input end of the red light freewheeling diode and the drain of the red light NMOS switch tube; A green light choke inductor, one end of which is electrically connected to the output end of the green light emitting diode light source group, and the other end of which is electrically connected to the input end of the green light freewheeling diode and the drain of the green light NMOS switch tube; A blue light choke inductor has one end electrically connected to the output end of the blue light emitting diode light source group, and the other end electrically connected to the input end of the blue light freewheeling diode and the drain of the blue light NMOS switch tube.

2. The multi-color light mixing circuit according to claim 1, characterized in that: The current amplitude of the red light emitting diode light source group, the current amplitude of the green light emitting diode light source group and the current amplitude of the blue light emitting diode light source group are the same.

3. The multi-color light mixing circuit according to claim 1, characterized in that: The current amplitude of the red light emitting diode light source group, the current amplitude of the green light emitting diode light source group and the current amplitude of the blue light emitting diode light source group are different.

4. The multi-color light mixing circuit according to claim 1, characterized in that: The number of the red light emitting diode light source groups, the number of the green light emitting diode light source groups and the number of the blue light emitting diode light source groups are the same.

5. The multi-color light mixing circuit according to claim 1, characterized in that: The number of the red light emitting diode light source groups, the number of the green light emitting diode light source groups and the number of the blue light emitting diode light source groups are different.

6. The multi-color light mixing circuit according to claim 1, characterized in that: The number of light sources in the red light emitting diode light source group, the number of light sources in the green light emitting diode light source group and the number of light sources in the blue light emitting diode light source group are the same.

7. The multi-color light mixing circuit according to claim 1, characterized in that: The number of light sources in the red light emitting diode light source group, the number of light sources in the green light emitting diode light source group and the number of light sources in the blue light emitting diode light source group are different.

8. The multi-color light mixing circuit according to claim 1, characterized in that: The number of light sources in the red light emitting diode light source group, the number of light sources in the green light emitting diode light source group, and the number of light sources in the blue light emitting diode light source group are 2 or more.

9. A camera, characterized in that: include: The multi-color light mixing circuit according to any one of claims 1 to 8; The camera body is electrically connected to the multi-color light mixing circuit.

10. A camera, characterized in that: include: The multi-color light mixing circuit according to any one of claims 1 to 8; The photographic subject is electrically connected to the multi-color light mixing circuit.

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