CN211047304U

CN211047304U - L ED display lamp control circuit for vehicle

Info

Publication number: CN211047304U
Application number: CN201922194527.3U
Authority: CN
Inventors: 刘兴岭
Original assignee: Shanghai Mottnick Automobile Technology Co ltd
Current assignee: Shanghai Mottnick Automobile Technology Co ltd
Priority date: 2019-12-10
Filing date: 2019-12-10
Publication date: 2020-07-17
Anticipated expiration: 2029-12-10

Abstract

The utility model relates to a control technical field discloses an automobile-used L ED display lamp control circuit, including control signal generation module, data retention module, L ED drive module and L ED light source group, L ED drive module is at least one constant current drive circuit, and a plurality of L ED lamps in every constant current drive circuit connection L ED light source group, a plurality of L ED lamps of constant current drive circuit timesharing turn-on connection, the utility model discloses a constant current drive circuit only drives a L ED in a section very short time quantum, and each L ED of circulation drive reduces constant current circuit in turn, by a wide margin reduce cost.

Description

L ED display lamp control circuit for vehicle

Technical Field

The utility model relates to the field of control technology, especially, relate to an automobile-used L ED display lamp control circuit.

Background

Referring to FIG. 1, with the widespread use of L ED lighting technology in automobiles, it is becoming more and more popular to utilize L ED for dynamic lighting displays in automobiles, such as running turn lights and ambience lights, etc. the system is generally made up of L EDs, each L ED is illuminated by a control system at programmed times and sequences to create the effect of a dynamic display.

The intelligent control module is generally composed of an MCU, the data shifting and maintaining module is used for reducing the requirement on the number of input and output pins of the MCU, the input and output pins of the MCU are needed if a plurality of L EDs are directly controlled by the MCU, and after the data shifting and maintaining module is arranged, the MCU only needs two pins of data and a clock to serially input L ED switch data into the data shifting and maintaining module, so that the cost of the MCU is reduced.

Referring to fig. 2, each L ED needs a constant current driving circuit to operate in the constant current mode, and when L EDs are provided in large numbers, the number of the constant current driving circuits is increased accordingly, thereby increasing the cost of the whole circuit.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving the above problem, provide an automobile-used L ED display lamp control circuit, only drive a L ED through a constant current drive circuit in a section very short time quantum, each L ED of cycle drive in turn reduces constant current circuit, reduction cost by a wide margin.

The utility model adopts the technical proposal that:

an L ED display lamp control circuit for a vehicle is characterized by comprising a control signal generation module, a data shift holding module, a L ED driving module and a L0 ED light source group, wherein the control signal generation module is used for generating a first clock signal and a data signal and transmitting the first clock signal and the data signal to the data shift holding module, the data shift holding module comprises a shift register, the data shift register is used for carrying out data shift on the data signal according to the first clock signal, the data shift holding module generates a driving control signal and transmits the driving control signal to the L ED driving module, the L ED driving module is used for driving corresponding L ED lamps in the L ED light source group to be turned on according to the driving control signal, the L ED driving module is at least one constant current driving circuit, each constant current driving circuit is connected with a plurality of L ED lamps in the L ED light source group, the control signal generation module comprises a time sharing conduction unit, and the constant current driving circuit conducts the connected plurality of L ED lamps in a time sharing mode according to signals of the time sharing conduction unit.

Further, the time interval of the time-sharing conduction unit is less than 0.05.

Further, when the constant current driving circuit is switched on in a time-sharing mode, the conducting current of the L ED lamps is N times of the original current, and N is the number of L ED lamps connected with the constant current driving circuit.

Furthermore, the data shift holding module also comprises a data holding register, the data holding register is connected to the data shift register, and the data shift register is correspondingly connected with each bit of the data holding register in parallel.

Further, the control signal generating module generates a second clock, and the data holding register is configured to hold data of the data signal according to the second clock signal.

Further, the control signal generation module is an MCU, and the time-sharing conduction unit is integrated in the MCU.

Further, the data shift holding module uses the chip 74HC594 or 74HC 595.

Furthermore, the number of the data shift holding modules is multiple, and a plurality of L ED lamps are controlled in a chip cascade mode.

The utility model has the advantages that:

(1) several L EDs share one constant current driving circuit, and the number of MCU pins is greatly reduced by data serial output, so that the circuit cost is reduced;

(2) a time-sharing conduction mechanism is adopted, and the flicker of each L ED lamp cannot be felt by utilizing the visual persistence effect of human eyes;

(3) by increasing the current through L ED lamp, the L ED brightness remained substantially unchanged;

(4) the lighting operation of the predetermined L ED lamp is realized by the data shift register and the data hold register connected in parallel.

Drawings

FIG. 1 is a diagram of a conventional L ED lamp dynamic control module layout;

FIG. 2 is a schematic diagram of an L ED constant current driving circuit in the prior art;

fig. 3 is a schematic diagram of an L ED constant current driving circuit of the present invention;

fig. 4 is a schematic diagram of the data shift register with an additional stage of data holding register for each bit based on fig. 3.

Detailed Description

The following describes in detail an embodiment of an L ED display lamp control circuit for a vehicle according to the present invention with reference to the accompanying drawings.

Referring to fig. 1 and 3, an L ED display lamp control circuit for a vehicle includes a control signal generating module, a data shift and hold module, a L ED driving module and a L ED light source group, wherein the control signal generating module is configured to generate a first clock signal (clk 1 in the figure) and a data signal and transmit the first clock signal and the data signal to the data shift and hold module, the data shift and hold module is configured to perform data shift on the data signal according to the clock signal and generate a driving control signal to transmit the driving control signal to the L ED driving module, and the L ED driving module is configured to drive a corresponding L ED lamp in the L ED light source group to light according to the driving control signal.

The L ED drive module is at least one constant current drive circuit, and each constant current drive circuit connects a plurality of L ED lamps in L ED light source group, and the control signal generation module includes the unit that switches on in a timesharing, the constant current drive circuit switches on a plurality of L ED lamps that connect according to the signal timesharing of unit that switches on in a timesharing.

Referring to fig. 4, the data shift holding module further includes a data holding register connected to the data shift register, and the data shift register is correspondingly connected in parallel to each bit of the data holding register. The control signal generation module generates a second clock signal (clk 2 in the figure), and the data holding register is used for carrying out data holding on the data signal according to the second clock signal.

The utility model discloses a reduce constant current drive circuit's quantity, make several L ED sharing a constant current drive circuit, then can reduce circuit cost by a wide margin.

When several L EDs share one constant current driving circuit, a time-sharing conduction mechanism is needed, namely, one constant current driving circuit only drives one L ED within a short period of time, each L ED. is driven in a rotation and circulation mode, due to the fact that the time interval is short, human eyes can not feel flickering when each L ED is lighted in the rotation and circulation mode through the visual persistence effect of the human eyes, the visual persistence of the human eyes can be achieved by setting the time interval of the time-sharing conduction unit to be less than 0.05s, and all L ED lamps of the L ED lamp group are in a continuously lighted state.

Referring to fig. 3, D1, D2, D3 and D4 share a constant current driving circuit, and a time-sharing conduction mechanism is adopted, D1 is conducted at time t1, D1 is turned off and D2 is conducted at time t2, D2 is turned off and D3 is conducted at time t3, D3 is turned off and D4 is turned on at time t4, and then the next cycle starts from time t1, because each 1ED has a short conduction time, the time period of one lighting cycle (from lighting to lighting again) of one 1ED (such as D1) is short, because the human eye has a persistence effect, the alternating change of brightness and darkness of the 1ED is not perceived, because each 1ED is not continuously conducted but only a fraction of the conduction time, and in the figure, four 1 EDs share one constant current driving circuit, the time of 1 is the same as the current of the continuous conduction current of the D1, and the current of the human eye is not perceived by the extinction of the 1 ED.

However, the average brightness of L ED is reduced a lot, therefore, it is necessary to increase the on-current of L ED, since the light intensity of L0 ED is proportional to the current value flowing through L1 ED, the increase of L ED current value can increase L ED brightness, thus making use of the persistence effect of human vision, and compensating the brightness decay of L ED caused by extinction in the period of time when L ED is extinguished, if the current of L ED when continuously conducting is i1, the on-current of L ED when time-sharing conducting is N x i1. times N, which can be selected according to the fact that several L ED share one constant current driving circuit and different types of L ED.

In fig. 3, if L ED lamps to be lit are not sequentially lit one by one, such as the middle L ED lamp, but since the data is serially input sequentially, the data for lighting the middle L ED lamp will necessarily pass through the previous data register first, causing the front L ED lamp to be lit first, and then the middle L ED lamp to be lit.

This problem is solved by a method, see fig. 4, in which a data holding register is provided between the data shift register and the driving circuit, the number of bits of the data holding register corresponds to the number of bits of the data shift register one-to-one, and the data shift register and the data holding register are connected in parallel, in the process of changing the data of the data shift register, there is no clock pulse (clk 2 in fig. 4) to trigger the change of the value of the data holding register, and the value of the data holding register will remain unchanged.

In practical application, chips with data shift registers and data holding registers integrated therein, such as 74HC594 and 74HC595, may be selected and directly connected to the MCU, and when L EDs are large in number, control may be implemented in a chip cascade manner.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims

1. An L ED display lamp control circuit for a vehicle is characterized by comprising a control signal generation module, a data shift holding module, a L ED driving module and a L0 ED light source group, wherein the control signal generation module is used for generating a first clock signal and a data signal and transmitting the first clock signal and the data signal to the data shift holding module, the data shift holding module comprises a data shift register, the data shift register is used for carrying out data shift on the data signal according to the first clock signal, the data shift holding module generates a driving control signal and transmits the driving control signal to the L ED driving module, the L ED driving module is used for driving corresponding L ED lamps in the L ED group to be turned on according to the driving control signal, the L ED driving module is at least one constant current driving circuit, each constant current driving circuit is connected with a plurality of L ED lamps in the L ED group, the control signal generation module comprises a time-sharing conduction unit, and the constant current driving circuit conducts the connected plurality of L ED lamps in a time-sharing conduction mode according to signals of the time-sharing conduction unit.

2. The L ED display lamp control circuit for vehicle according to claim 1, wherein the time interval of the time-sharing conducting unit is less than 0.05.

3. The L ED display lamp control circuit for vehicle according to claim 1, wherein when the constant current driving circuit is turned on in a time-sharing manner, the turn-on current of L ED lamps is N times of the original current, and N is the number of L ED lamps connected with the constant current driving circuit.

4. The L ED display lamp control circuit for vehicle according to any one of claims 1-3, wherein the data shift and hold module further comprises a data hold register connected to the data shift register, the data shift register is connected in parallel with each bit of the data hold register.

5. The L ED display lamp control circuit for vehicle according to claim 4, wherein the control signal generating module generates a second clock, and the data holding register is used to hold the data signal according to the second clock.

6. The L ED display lamp control circuit for the vehicle according to any one of claims 1 to 3, wherein the control signal generating module is an MCU, and the time-sharing conducting unit is integrated in the MCU.

7. The L ED display lamp control circuit for vehicle according to claim 5, wherein the data shift holding module uses a chip 74HC594 or 74HC 595.

8. The L ED display lamp control circuit for vehicle according to claim 7, wherein the data shift and hold module is multiple, and controls multiple L ED lamps in a chip cascade manner.