CN211831257U

CN211831257U - True and false flash compatible flash circuit and terminal equipment

Info

Publication number: CN211831257U
Application number: CN202020419780.4U
Authority: CN
Inventors: 丁永波; 吴胜广
Original assignee: Shenzhen Weibu Information Co Ltd
Current assignee: Shenzhen Weibu Information Co Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2020-10-30
Anticipated expiration: 2030-03-27

Abstract

The embodiment of the utility model discloses a true and false flash compatible flash circuit and terminal equipment, the terminal equipment comprises a mainboard, the mainboard is provided with a true and false flash compatible flash circuit, a processor and a light detection circuit; the flash circuit is connected with the processor, and the processor is connected with the light detection circuit; the light detection circuit is used for detecting the light brightness state in the environment and outputting a corresponding detection signal to the processor; when the processor detects that the photographing function is started, whether an effective true supply control signal or a false flash control signal is output or not is judged according to the detection signal; the flash circuit detects the input states of the true power supply control signal and the false flash control signal, starts true flash when the true power supply control signal is input, and starts false flash when the false flash control signal is input. The flash circuit can select true flash or false flash according to requirements, thereby solving the problem that the existing flash circuit can not select other flash control modes.

Description

True and false flash compatible flash circuit and terminal equipment

Technical Field

The utility model relates to the field of electronic technology, especially, relate to a true and false compatible flash of light circuit and terminal equipment that dodges.

Background

When terminal equipment such as panel computer, cell-phone uses the camera to shoot under the environment of night or light darker, need increase the luminance of light, can open the LED lamp usually to increase the luminance of light in the twinkling of an eye of shooing, even also can shoot out clear photo under the environment that light is darker. The LED lamp mainly has the effects of supplementing light in a dark environment and being used as a flashlight. However, the existing flash circuit is usually driven by a relatively high-end chip, two control signals (one signal controls whether to supply power to the chip, and the other signal controls whether to start flashing) are required, power consumption is relatively high, some terminal devices may not need a high-end flash control mode, but the existing flash circuit cannot select other flash control modes and cannot meet flash requirements of different customers.

SUMMERY OF THE UTILITY MODEL

To the above technical problem, the embodiment of the utility model provides a true and false compatible flash of light circuit and terminal equipment of dodging is provided to solve the problem that current flash of light circuit can not select other flash of light control modes.

The embodiment of the utility model provides a true and false flash compatible flash circuit connects the treater, and it includes true flashing module, false flashing module and LED lamp, and true flashing module and treater select to be connected, false flashing module and treater select to be connected, and the LED lamp is connected true flashing module and false flashing module;

when the real flash module receives an effective real power supply control signal output by the processor, the corresponding flash current is output to drive the LED lamp to flash;

and when the false flash module receives an effective false flash control signal output by the processor, the false flash module controls the on-off of a circuit from the LED lamp to the ground to control the LED lamp to flash.

Optionally, in the true-false flash compatible flash circuit, the true flash module includes a flash driving chip, a first resistor, a second resistor, a third resistor, and a first capacitor;

the VIN pin of the flash driving chip is connected with a power supply end, and the C1 pin of the flash driving chip is connected with the C2 pin of the flash driving chip through a first capacitor; the T/F pin of the flash driving chip is selectively connected with the SPI0_ MO pin of the processor, the EN pin of the flash driving chip is selectively connected with the SPI0_ MI pin of the processor, and the VOUT pin of the flash driving chip is connected with the false flash module and the anode of the LED lamp through a first resistor; the FB pin of the flash driving chip is connected with one end of the second resistor, the false flash module and the cathode of the LED lamp, and the RSET pin of the flash driving chip is connected with one end of the third resistor; the PGND1 pin, the PGND2 pin and the SGND pin of the flash drive chip are all grounded, and the other end of the second resistor and the other end of the third resistor are all grounded.

Optionally, in the true-false flash compatible flash circuit, the true flash module further includes a second capacitor, a third capacitor, and a fourth resistor;

the second capacitor is connected between the VIN pin of the flash driving chip and the ground, the third capacitor is connected between the VOUT pin of the flash driving chip and the ground, and the fourth resistor is connected between the EN pin of the flash driving chip and the ground.

Optionally, in the true-false flash compatible flash circuit, the false flash module includes a triode, a fifth resistor, and a sixth resistor;

the base electrode of the triode is connected with one end of the fifth resistor, the other end of the fifth resistor is selectively connected with the SPI0_ CK pin of the processor, the emitting electrode of the triode is grounded, the collecting electrode of the triode is connected with the FB pin of the flash driving chip and the negative electrode of the LED lamp, one end of the sixth resistor is connected with the positive electrode of the LED lamp, and the other end of the sixth resistor is connected with the power supply end.

Optionally, in the true-false flash compatible flash circuit, the false flash module further includes a seventh resistor and an eighth resistor, one end of the seventh resistor is connected to the base of the triode and one end of the fifth resistor, the other end of the seventh resistor is grounded, the eighth resistor is connected to the collector of the triode, and the other end of the eighth resistor is connected to the cathode of the FB pin LED lamp of the flash driving chip.

A second aspect of the embodiment of the present invention provides a terminal device, including a motherboard, wherein the motherboard is provided with a processor, wherein the motherboard is further provided with the flash circuit compatible with true and false flashes, the flash circuit compatible with true and false flashes is connected to the processor, and the processor is connected to the optical inspection circuit;

the light detection circuit is used for detecting the light brightness state in the environment and outputting a corresponding detection signal to the processor;

when the processor detects that the photographing function is started, whether an effective true supply control signal or a false flash control signal is output or not is judged according to the detection signal;

the flash circuit detects the input states of the true power supply control signal and the false flash control signal, starts true flash when the true power supply control signal is input, and starts false flash when the false flash control signal is input.

In the technical scheme provided by the embodiment of the utility model, the terminal device comprises a mainboard, and a flash circuit, a processor and a light detection circuit which are compatible with true and false flashes are arranged on the mainboard; the flash circuit is connected with the processor, and the processor is connected with the light detection circuit; the light detection circuit is used for detecting the light brightness state in the environment and outputting a corresponding detection signal to the processor; when the processor detects that the photographing function is started, whether an effective true supply control signal or a false flash control signal is output or not is judged according to the detection signal; the flash circuit detects the input states of the true power supply control signal and the false flash control signal, starts true flash when the true power supply control signal is input, and starts false flash when the false flash control signal is input. The flash circuit can select true flash or false flash according to requirements, thereby solving the problem that the existing flash circuit can not select other flash control modes.

Drawings

Fig. 1 is a block diagram of a terminal device according to an embodiment of the present invention.

Fig. 2 is a schematic circuit diagram of a flash circuit compatible with true and false flashes according to an embodiment of the present invention.

Fig. 3 is a schematic circuit diagram of a processor according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. The embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts, belong to the protection scope of the present invention.

Referring to fig. 1 and fig. 2, a terminal device provided in an embodiment of the present invention includes a camera and a motherboard, wherein the motherboard is provided with a flash circuit 10 compatible with true and false flashes, a processor 20 and a light detection circuit, the flash circuit 10 compatible with true and false flashes is connected to the processor 20, and the processor 20 is connected to the camera and the light detection circuit; the light detection circuit is used for detecting the light brightness state in the external environment of the camera and outputting a corresponding detection signal to the processor 20; when the processor 20 detects that the photographing function is started, whether a valid true supply control signal (FLASH _ T/F, FLASH _ EN) or a false FLASH control signal FLASH _ LED is output is judged according to the detection signal. The true-false flash compatible flash circuit 10 detects the input states of the true supply control signal and the false flash control signal, starts the true flash when the true supply control signal is input, and starts the false flash when the false flash control signal is input. The false flash of light is the same with the flash of light effect that the true flash of light is glistened, and only circuit structure between them is different, and the circuit that the false flash of light is glistened is simple and used material device less than the circuit that the true flash of light, leads to the power consumption that the false flash of light is lower than the default than the true flash of light.

The terminal equipment mainly comprises all terminal equipment for taking pictures through a camera, such as a tablet personal computer and a mobile phone. The circuit structure, connection relation and functional principle of the camera, the processor 20 and the optical detection circuit are the prior art; the processor 20 may be a processor of the concurrency department, for example, a processor of the model MT8765 (only pins related to this embodiment are shown here, and other pins are related to the prior art and are not described herein); the light detection circuit can adopt a light sensor, a light sensor and the like. The flash duration of the true and false flashes is consistent with the duration of the photo taking, which is the prior art and is not described herein.

In this embodiment, the real supply control signal (the real FLASH control signal FLASH _ T/F and the power supply control FLASH _ EN) which is currently output by the processor 20 and used for controlling whether the real FLASH is turned on is mainly used, and a dummy FLASH control signal FLASH _ LED is added to control whether the dummy FLASH is turned on. When the circuit board is produced, if a customer selects to use the false FLASH with low power consumption, the output pin of a false FLASH control signal FLASH _ LED of the processor is connected with the FLASH circuit 10, the output pin of a true power supply control signal (a true FLASH control signal FLASH _ T/F and a power supply control FLASH _ EN) is not connected with the FLASH circuit 10, and no matter whether the true FLASH control signal FLASH _ T/F and the power supply control FLASH _ EN are effective or not, the false FLASH can only be used due to the fact that the true FLASH control signal FLASH _ T/F and the power supply control FLASH _ EN are not connected; if the customer selects to use the true FLASH, the output pin of the false FLASH control signal FLASH _ LED is not connected with the FLASH circuit 10, the output pin of the true power supply control signal (the true FLASH control signal FLASH _ T/F and the power supply control FLASH _ EN) is connected with the FLASH circuit 10, and no matter whether the false FLASH control signal FLASH _ LED is effective or not, the false FLASH control signal FLASH _ LED can only be used for the true FLASH because the false FLASH control signal FLASH _ LED is not connected; the method and the device enable a client to select the true flash or the false flash according to the power consumption requirement, thereby solving the problem that the existing flash circuit can not select other flash control modes.

It should be understood that, in specific implementation, the flash circuit 10 may also be connected to all three control signals in the control signal group, a true flash icon and a false flash icon are added in the terminal device, and the processor controls the valid states of the three control signals according to the click states of the two icons, so that the true flash or the false flash can be selectively started. If the processor 20 detects that the true FLASH icon is clicked, the output true FLASH control signal FLASH _ T/F and the power supply control FLASH _ EN are valid, and the false FLASH control signal FLASH _ LED is invalid, that is, only the true FLASH line in the FLASH circuit 10 is started; similarly, if the processor 20 detects that the false FLASH icon is clicked, the output true FLASH control signal FLASH _ T/F and the power supply control FLASH _ EN are invalid, and the false FLASH control signal FLASH _ LED is valid, only the false FLASH line in the FLASH circuit 10 can be started; the control signal may be set to be active (pulse signal) when the control signal is at a high level, and the low level indicates inactive.

Referring to fig. 2 and fig. 3 together, the flash circuit 10 compatible with true and false flashes includes a true flash module 110, a false flash module 120, and an LED lamp CN, wherein the true flash module 110 is selectively connected to the processor, the false flash module 120 is selectively connected to the processor, and the LED lamp CN is connected to the true flash module 110 and the false flash module 120; when the true FLASH module 110 receives true supply control signals (two signals including a true FLASH control signal FLASH _ T/F and a power supply control FLASH _ EN) output by the processor, the corresponding FLASH current is output to drive the LED lamp CN to FLASH; when the false FLASH module 120 receives a false FLASH control signal (a false FLASH control signal FLASH _ LED) output by the processor, the on-off of the ground loop of the LED lamp CN is controlled to control the LED lamp to FLASH.

In this embodiment, the true flash module 110 includes a flash driving chip U1, a first resistor R1, a second resistor R2, a third resistor R3, and a first capacitor C1; the VIN pin of the flash driving chip U1 is connected with a power supply terminal VBAT (can supply power to a battery), and the C1 pin of the flash driving chip U1 is connected with the C2 pin of the flash driving chip U1 through a first capacitor C1; the T/F pin of the flash driving chip U1 is selectively connected with the SPI0_ MO pin of the processor, the EN pin of the flash driving chip U1 is selectively connected with the SPI0_ MI pin of the processor, and the VOUT pin of the flash driving chip U1 is connected with the false flash module 120 and the anode of the LED lamp CN through a first resistor R1; the FB pin of the flash driving chip U1 is connected to one end of the second resistor R2, the false flash module 120 and the cathode of the LED lamp CN, and the RSET pin of the flash driving chip U1 is connected to one end of the third resistor R3; the pin PGND1, the pin PGND2 and the pin SGND of the flash driver chip U1 are all grounded, and the other end of the second resistor R2 and the other end of the third resistor R3 are all grounded.

The model of the flash driving chip U1 is preferably SGM3140, the first resistor R1 is a resistor for isolating the power supply of the dummy flash module 120, the second resistor R2 is a flash current limiting resistor, and the third resistor R3 is a reset resistor of the flash driving chip U1. The selective connection is that the layout (position and routing) of a certain module (specifically, a device) is set on the circuit board, the input end or the output end (specifically, corresponding to the pin to be selectively connected to the device) of the module is suspended and is not connected to other modules or devices, and the connection is performed after the subsequent customer determines the connection (i.e., the pin is soldered to the corresponding pad).

In this embodiment, the T/F pin and the EN pin of the flash driver chip U1 are selectively connected to the SPI0_ MO pin and the SPI0_ MI pin of the processor, respectively, and are only really connected when the client confirms to use the real flash line. The power supply control signal FLASH _ EN is used for controlling whether the FLASH power supply switch of the FLASH driving chip U1 is turned on, the power supply to the FLASH driving chip U1 is turned on by the switch at a high level, and the power supply is stopped when the switch is turned off at a low level. The true FLASH control signal FLASH _ T/F is used for controlling whether to start the FLASH function or not, when the FLASH function is in a high level, the FLASH is started, and the VOUT pin of the FLASH drive chip U1 outputs corresponding FLASH current to drive the LED lamp CN to be lightened; and when the voltage is low level, the VOUT pin has no flash current output.

Preferably, the true flash module 110 further includes a second capacitor C2, a third capacitor C3, and a fourth resistor R4; the second capacitor C2 is connected between the VIN pin of the flash driver chip U1 and ground, the third capacitor C3 is connected between the VOUT pin of the flash driver chip U1 and ground, and the fourth resistor R4 is connected between the EN pin of the flash driver chip U1 and ground.

The second capacitor C2 is used for filtering the supply voltage input by the power supply terminal VBAT, so that the flash driver chip U1 operates more stably. The third capacitor C3 is used to filter the output flash current, making the flash effect more stable. The fourth resistor R4 is a pull-down resistor of the EN pin of the FLASH driving chip U1, and pulls down the EN pin when the power supply control signal FLASH _ EN is invalid, so that the FLASH driving chip U1 is controlled to stop working, and the FLASH driving chip U1 is prevented from being started by mistake due to pulse interference.

In this embodiment, the dummy flash module 120 includes a transistor Q1, a fifth resistor R5, and a sixth resistor R6; the base electrode of the triode Q1 is connected with one end of a fifth resistor R5, the other end of the fifth resistor R5 is selectively connected with an SPI0_ CK pin of the processor 20, the emitting electrode of the triode Q1 is grounded, the collecting electrode of the triode Q1 is connected with an FB pin of the flash driving chip U1 and the cathode of the LED lamp CN, one end of a sixth resistor R6 is connected with the anode of the LED lamp CN, and the other end of the sixth resistor R6 is connected with a power supply end VBAT.

The triode Q1 is an NPN triode; the fifth resistor R5 is a current-limiting resistor and is used for avoiding sudden change of high voltage of the processor from burning out the triode Q1; the sixth resistor R6 is a false flash current limiting resistor, and the brightness of the flash can be adjusted by selecting R6 with different resistance values.

The base of transistor Q1 is selectively coupled to the SPI0_ CK pin of the processor in this embodiment, and is only positively coupled if the customer confirms that a false flash line is used. The false FLASH control signal FLASH _ LED is used for controlling whether to start false FLASH, when the level is high, the triode Q1 is conducted, the LED lamp CN forms a loop to the ground to be lightened, and when the level is low, no loop enables the false FLASH to be turned off.

Preferably, the false flash module 120 further includes a seventh resistor R7 and an eighth resistor R8, one end of the seventh resistor R7 is connected to the base of the transistor Q1 and one end of the fifth resistor R5, the other end of the seventh resistor R7 is grounded, the eighth resistor R8 is connected to the collector of the transistor Q1, and the other end of the eighth resistor R8 is connected to the negative electrode of the FB pin LED CN of the flash driving chip U1.

The seventh resistor R7 is a pull-down resistor, and is used to prevent the transistor Q1 from being turned on by an interference signal when the false FLASH control signal FLASH _ LED is invalid. The eighth resistor R8 is a current limiting resistor, and further controls the brightness of the flash lamp.

In this embodiment, the LED lamp CN can also implement a flashlight function, and when the processor detects that the flashlight icon is clicked, outputs a continuous high-level true FLASH control signal FLASH _ T/F, a power supply control FLASH _ EN, and a false FLASH control signal FLASH _ LED; if the true flash module 110 is connected with the processor, the LED lamp CN is lightened by the output current of the flash driving chip; if the false flash module 120 is connected to the processor, the LED lamp CN is turned on by forming a loop through conduction of the triode.

Referring to fig. 1 to fig. 3, if the true flash is selected, the T/F pin and the EN pin of the flash driver chip U1 are respectively connected to the SPI0_ MO pin and the SPI0_ MI pin of the processor, and at this time, the other end of the fifth resistor R5 or the base of the transistor Q1 is floating, the operation principle of the terminal device is as follows:

when the light detection circuit detects that the light is dark, a dark light detection signal is output to the processor; when the processor 20 detects that the photographing function is started, a high-level pulse true FLASH control signal FLASH _ T/F and a power supply control FLASH _ EN are output according to the dim light detection signal, the rising edge of the power supply control FLASH _ EN is earlier than the rising edge of the true FLASH control signal FLASH _ T/F by a preset time (the specific numerical value is the prior art), and the falling edge of the power supply control FLASH _ EN and the falling edge of the true FLASH control signal FLASH _ T/F fall synchronously. The FLASH driving chip U1 controls the FLASH _ EN to be electrified to start working according to the high-level power supply, and outputs corresponding FLASH current from the VOUT pin according to the high-level true FLASH control signal FLASH _ T/F, the FLASH current flows in from the anode of the LED lamp CN, flows out from the cathode of the LED lamp CN and is fed back to the FB pin of the FLASH driving chip U1, so that a loop is formed to enable the LED lamp CN to emit light. When the high level is changed into the low level, the FLASH driving chip U1 stops working and stops the output of the FLASH current, the LED lamp CN is turned off, and the duration time of the high level of the true FLASH control signal FLASH _ T/F is consistent with the photographing duration time, so that one-time true FLASH is realized.

If false flash is selected to save power consumption, the other end of the fifth resistor R5 or the base of the triode Q1 is connected with the SPI0_ CK pin of the processor, and at this time, the T/F pin and the EN pin of the flash driver chip U1 are suspended, the operating principle of the terminal device is as follows:

when the light detection circuit detects that the light is dark, a dark light detection signal is output to the processor; when the processor 20 detects that the photographing function is started, the processor outputs a high-level pulse false FLASH control signal FLASH _ LED according to the dim light detection signal, the duration of the high level is consistent with the photographing duration, the triode Q1 is conducted to form a ground loop, the power supply end supplies power to the LED lamp CN, and the LED lamp CN is lightened. When the high level is changed into the low level, the triode Q1 is cut off to disconnect the loop, and the LED lamp CN is extinguished, so that one-time false flash is realized.

In specific implementation, in order to save material cost, the positions and the routing of each electronic element in the true flash module 110 and the false flash module 120 can be preset on the circuit board according to the circuit connection relationship shown in fig. 2, and when a customer selects to use the true flash or the false flash, only the electronic element of the true flash module 110 is soldered on the circuit board, or only the electronic element of the false flash module 120 is soldered; therefore, only the true flash module 110 and the flash lamp CN or only the false flash module 120 and the flash lamp CN are arranged on the circuit board, and partial material cost can be saved. The processor 20 still retains the pins of the true FLASH control signal FLASH _ T/F, the power supply control FLASH _ EN and the false FLASH control signal FLASH _ LED; when only the true FLASH module 110 is arranged on the circuit board, the pin of the false FLASH control signal FLASH _ LED is directly suspended without the fifth resistor R5 or the triode Q1, so that misoperation cannot be caused; similarly, when only the false FLASH module 120 is on the circuit board, the pins of the true FLASH control signal FLASH _ T/F and the power supply control FLASH _ EN are directly suspended because the FLASH driving chip U1 is not provided.

To sum up, the utility model provides a true and false compatible flash of light circuit and terminal equipment of dodging, under the condition that does not influence the current flash of light performance of terminal equipment, through increasing the false circuit of dodging and changing current true circuit of dodging, obtain a flash of light circuit that can compatible true and false dodge, this flash of light circuit is nimble changeable with the connected mode of treater, can confirm again for true dodging or false dodging according to customer's demand to satisfy different customer's consumption demand. Meanwhile, when false flashing is selected, due to the fact that the false flashing module is simple in circuit and few in material, flashing control can be conducted only through one false flashing control signal, and circuit power consumption is greatly reduced.

The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims

1. A flash circuit compatible with true and false flashes is connected with a processor and is characterized by comprising a true flash module, a false flash module and an LED lamp, wherein the true flash module is selectively connected with the processor, the false flash module is selectively connected with the processor, and the LED lamp is connected with the true flash module and the false flash module;

2. The flash circuit of claim 1, wherein the flash module comprises a flash driver chip, a first resistor, a second resistor, a third resistor, and a first capacitor;

3. The true-false flash compatible flash circuit of claim 2, wherein the true flash module further comprises a second capacitor, a third capacitor and a fourth resistor;

4. The true-false flash compatible flash circuit of claim 2, wherein the false flash module comprises a transistor, a fifth resistor and a sixth resistor;

5. The flash circuit of claim 4, wherein the flash module further comprises a seventh resistor and an eighth resistor, one end of the seventh resistor is connected to the base of the triode and one end of the fifth resistor, the other end of the seventh resistor is grounded, the eighth resistor is connected to the collector of the triode, and the other end of the eighth resistor is connected to the cathode of the FB pin LED lamp of the flash driver chip.

6. A terminal device, comprising a main board, wherein a processor and a light detection circuit are disposed on the main board, and the main board is further provided with a true-false flash compatible flash circuit according to any one of claims 1-5, the true-false flash compatible flash circuit is connected to the processor, and the processor is connected to the light detection circuit;