CN107277982A - LED light emission drive circuits - Google Patents
LED light emission drive circuits Download PDFInfo
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- CN107277982A CN107277982A CN201710655562.3A CN201710655562A CN107277982A CN 107277982 A CN107277982 A CN 107277982A CN 201710655562 A CN201710655562 A CN 201710655562A CN 107277982 A CN107277982 A CN 107277982A
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- Prior art keywords
- bjt
- led light
- branch road
- light emission
- led
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/10—Controlling the intensity of the light
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- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
- Control Of El Displays (AREA)
Abstract
The embodiments of the invention provide a kind of LED light emission drive circuits.The LED light emission drive circuits are used to drive LED light emitting arrays, the LED light emitting arrays are made up of multiple branch circuit parallel connections, multiple LED are in series with every branch road, the dipole triode BJT for brilliance control is in series with every branch road, the colelctor electrode of the BJT is connected on the branch road with emitter stage, and the base stage of the BJT is used for the input of drive signal.LED light emission drive circuits provided in an embodiment of the present invention can improve the brightness uniformity of LED array of display.
Description
Technical field
The present embodiments relate to technical field of semiconductors, more particularly to a kind of LED light emission drive circuits.
Background technology
Fig. 1 shows the LED array of existing LED display.Referring to Fig. 1, LED array is parallel with one another by different branch roads
Constitute.On each branch road, different LED are sequentially connected in series.The driving voltage of display by each branch road first LED sun
Pole is inputted.When driving voltage is high level, the LED in respective branch is lit.
The type of drive of existing LED array has following defect, and multiple branch roads are controlled by an output port, often
When multiple LED forward drop deviations of one branch road are cumulative, the current deviation for flowing through each branch road is larger, ultimately results in LED
LED brightness irregularities in matrix lamp plate.
The content of the invention
For above-mentioned technical problem, the embodiments of the invention provide a kind of LED light emission drive circuits, shown with improving LED
The brightness uniformity of array.
The embodiments of the invention provide a kind of LED light emission drive circuits, for driving LED light emitting arrays, the LED lights
Array is made up of multiple branch circuit parallel connections, is in series with multiple LED, every branch road and is in series with for brilliance control on every branch road
Dipole triode BJT, the BJT colelctor electrode are connected on the branch road with emitter stage, and the base stage of the BJT is used to drive
The input of dynamic signal.
LED light emission drive circuits provided in an embodiment of the present invention, by the BJT that connected on each LED branch road, improve LED
The brightness uniformity of array of display.
Brief description of the drawings
By reading the detailed description made to non-limiting example made with reference to the following drawings, of the invention is other
Feature, objects and advantages will become more apparent upon：
Fig. 1 is the circuit structure diagram for the LED light emission drive circuits that prior art is provided；
Fig. 2 is the circuit structure diagram for the LED light emission drive circuits that first embodiment of the invention is provided；
Fig. 3 is the circuit structure diagram for the LED light emission drive circuits that second embodiment of the invention is provided；
Fig. 4 is the circuit structure diagram for the LED light emission drive circuits that third embodiment of the invention is provided；
Fig. 5 is the circuit structure diagram for the LED light emission drive circuits that fourth embodiment of the invention is provided.
Embodiment
The present invention is described in further detail with reference to the accompanying drawings and examples.It is understood that this place is retouched
The specific embodiment stated is used only for explaining the present invention, rather than limitation of the invention.It also should be noted that, in order to just
Part related to the present invention rather than entire infrastructure are illustrate only in description, accompanying drawing.
First embodiment
Present embodiments provide a kind of technical scheme of LED light emission drive circuits.In the technical scheme, for brightness control
The bipolar junction transistor (Bipolar junction transistor, BJT) of system is NPN type BJT, also, the BJT
Colelctor electrode is connected with the last negative electrode in the LED being serially connected on the branch road, the emitter stage of the BJT and the branch road
The current-limiting resistance connection of upper series connection, also, the other end ground connection of the current-limiting resistance.
Fig. 2 shows the circuit theory diagrams of the present embodiment.Referring to Fig. 2, LED light emission drive circuits are parallel with one another by several
Branch road constitute.Being in series with several on each branch road is used for the LED of luminescence display, for the BJT T21-T25 of brilliance control,
And the current-limiting resistance R21-R25 for current limliting.
In the LED light emission drive circuits shown in Fig. 1, whether the LED connected on each branch road conducting passes through one
Input port is controlled.So, transient current on each direct current differs greatly, and eventually results in different branch
LED display brightness it is uneven.
In the LED light emission drive circuits that the present embodiment is provided, the driving DC voltage of each branch road parallel with one another is protected
Hold constant, be+15V, and series connection one is used for the NPN type BJT of brilliance control on each branch road.This NPN type BJT's
Colelctor electrode is connected with the last negative electrode in the LED being serially connected on the branch road, its emitter stage limit corresponding with the branch road
Leakage resistance R21-R25 connections.Moreover, NPN type BJT base stage is used for the input of drive signal.
When inputting effective drive signal by NPN type BJT base stage, colelctor electrode and the emitter stage of the BJT are switched on, right
Answer the LED connected on branch road to be also switched on, start to light.Because the current-limiting resistance R21-R25 connected on each branch road has identical
Conducting electric current in resistance, therefore each direct current is stabilized on fixed current value.Because each LED conducting electric current takes
Value is identical, is not in obvious luminance difference between the LED on each branch road, it is achieved thereby that the display of LED display modules
Brightness uniformity.
Further, in the present embodiment, the BJT connected on each branch road base stage also connects with an input diode
Connect.When connecting above-mentioned input diode, the negative electrode of the input diode is directly connected with BJT base stage.The input diode
Effect is, it is ensured that the one-way conduction of driving voltage.
The present embodiment is by the BJT that is connected in different branch for brilliance control, and the display for realizing LED display is bright
Degree homogenization.
Second embodiment
Present embodiments provide another technical scheme of LED light emission drive circuits.In the technical scheme, for brightness
The BJT of control is similarly NPN type BJT, also, the colelctor electrode of the BJT is connected with the current-limiting resistance connected on the branch road, institute
State BJT grounded emitter.
Referring to Fig. 2, the difference of the present embodiment and first embodiment of the invention is, on each branch road different elements it
Between series sequence can change.In the first embodiment of the invention, the series sequence of element is on each branch road：LED、
BJT T21-T25, current-limiting resistance R21-R25.And in the present embodiment, on each branch road the series sequence of element then become in order to：
LED, current-limiting resistance R31-R35, BJT T31-T35.
It is with first embodiment of the invention something in common, each BJT type is constant, is still NPN type BJT.In addition,
It is still the high-pressure side that colelctor electrode connects each branch road, and emitter stage connects the low-pressure end of each branch road.
In addition, each BJT base stage is still used for the input of drive signal.Further, aforementioned base equally can be with
With for ensureing that the input diode of one-way conduction is connected.In the case, what is be directly connected to base stage is input diode
Negative electrode.
The present embodiment is by the BJT that is connected in different branch for brilliance control, and the display for realizing LED display is bright
Degree homogenization.
3rd embodiment
Present embodiments provide the yet another technique scheme of LED light emission drive circuits.In the technical scheme, for brightness
The BJT of control type is no longer NPN type, and is become for positive-negative-positive.Meanwhile, the emitter stage of the BJT is connected with current-limiting resistance,
The colelctor electrode of the BJT is connected with the anode of first LED in the LED being serially connected on the branch road, also, the current-limiting resistance
The other end be connected with the driving voltage input of the branch road.
Referring to Fig. 3, the difference of the present embodiment and first embodiment of the invention is, BJT type is changed into from NPN type
Positive-negative-positive.Meanwhile, the series sequence on each branch road between different elements is also changed.In first embodiment of the invention
In, the connection order of element is on each branch road：LED, BJT T21-T25, current-limiting resistance R21-R25.And in the present embodiment,
The series sequence of element is changed on each branch road：Current-limiting resistance R41-R45, BJT T41-T45, LED.
In the present embodiment, BJT base stage is still used for the input of drive signal.Unlike, effective drive signal
Polarity is changed.
In addition, aforementioned base can equally connect input diode.But, in the present embodiment, it is directly connected to base stage
Be input diode anode.The function of the input diode is still guarantee one-way conduction.
The present embodiment is by the BJT that is connected in different branch for brilliance control, and the display for realizing LED display is bright
Degree homogenization.
Fourth embodiment
Present embodiments provide also a kind of technical scheme of LED light emission drive circuits.In the technical scheme, for brightness
The BJT of control type is positive-negative-positive.Meanwhile, the BJT is positive-negative-positive BJT, the driving of the emitter stage of the BJT and the branch road
Voltage input end is connected, and the colelctor electrode of the BJT is connected with the current-limiting resistance connected on the sub- road.
Referring to Fig. 4, the difference of the present embodiment and first embodiment of the invention is, BJT type has NPN type to be changed into
Positive-negative-positive.Meanwhile, the series sequence on each branch road between different elements is also changed.In first embodiment of the invention
In, the connection order of element is on each branch road：LED, BJT T21-T25, current-limiting resistance R21-R25.And in the present embodiment,
The series sequence of element is changed on each branch road：BJTT51-T55, current-limiting resistance R51-R55, LED.
In the present embodiment, BJT base stage is still used for the input of drive signal.Unlike, effective drive signal
Polarity is changed.
In addition, aforementioned base can equally connect input diode.But, in the present embodiment, it is directly connected to base stage
Be input diode anode.The function of the input diode is still guarantee one-way conduction.
The present embodiment is by the BJT that is connected in different branch for brilliance control, and the display for realizing LED display is bright
Degree homogenization.
The circuit of the present invention can be applied not only to the brightness stability of LED display, can also be applied to OLED, LCD etc.
The brightness stability of other species display screens.
The preferred embodiments of the present invention are the foregoing is only, are not intended to limit the invention, for those skilled in the art
For, the present invention can have various changes and change.It is all any modifications made within spirit and principles of the present invention, equivalent
Replace, improve etc., it should be included in the scope of the protection.
Claims (7)
1. a kind of LED light emission drive circuits, for driving LED light emitting arrays, the LED light emitting arrays are by multiple branch circuit parallel connection structures
Into being in series with multiple LED on every branch road, it is characterised in that be in series with the dipole for brilliance control on every branch road
Triode BJT, the BJT colelctor electrode are connected on the branch road with emitter stage, and the base stage of the BJT is used for drive signal
Input.
2. LED light emission drive circuits according to claim 1, it is characterised in that the BJT is NPN type BJT, the BJT
Colelctor electrode be connected with the last negative electrode in the LED being serially connected on the branch road, the emitter stage of the BJT and the branch
The current-limiting resistance connection connected on road, also, the other end ground connection of the current-limiting resistance.
3. LED light emission drive circuits according to claim 1, it is characterised in that the BJT is NPN type BJT, the BJT
Colelctor electrode be connected with the current-limiting resistance connected on the branch road, the grounded emitter of the BJT.
4. LED light emission drive circuits according to claim 1, it is characterised in that the BJT is positive-negative-positive BJT, the BJT
Emitter stage be connected with current-limiting resistance, first LED sun in the LED being serially connected on the colelctor electrode of the BJT and the branch road
Pole is connected, also, the other end of the current-limiting resistance is connected with the driving voltage input of the branch road.
5. LED light emission drive circuits according to claim 1, it is characterised in that the BJT is positive-negative-positive BJT, the BJT
Emitter stage be connected with the driving voltage input of the branch road, the current limliting that the colelctor electrode of the BJT is connected with the sub- road
Resistance is connected.
6. according to any described LED light emission drive circuits of claim 2 to 5, it is characterised in that the base stage of the BJT with it is defeated
Enter diode connection.
7. LED light emission drive circuits according to claim 6, it is characterised in that connected on each branch road parallel with one another
Current-limiting resistance has identical resistance value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710655562.3A CN107277982A (en) | 2017-08-03 | 2017-08-03 | LED light emission drive circuits |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710655562.3A CN107277982A (en) | 2017-08-03 | 2017-08-03 | LED light emission drive circuits |
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| CN107277982A true CN107277982A (en) | 2017-10-20 |
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| CN201710655562.3A Pending CN107277982A (en) | 2017-08-03 | 2017-08-03 | LED light emission drive circuits |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109377940A (en) * | 2018-11-22 | 2019-02-22 | 北京双竞科技有限公司 | A kind of LED display character driving circuit of Auto-matching section brightness |
| CN112287630A (en) * | 2019-07-09 | 2021-01-29 | 苏州市悠越电子有限公司 | Method for improving resistance value of inner loop of keyboard and optimizing layout of printed circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101106852A (en) * | 2007-06-25 | 2008-01-16 | 四川大学 | Current constant and light adjusting control circuit for luminescent LED array |
| CN102970803A (en) * | 2012-12-05 | 2013-03-13 | 成都芯源系统有限公司 | Apparatus and method for driving multiple strings of light emitting diodes |
| CN204721658U (en) * | 2015-05-25 | 2015-10-21 | 延锋伟世通电子科技（南京）有限公司 | With the automobile multiple constant current LED illumination circuit of temperature detection |
| CN207518896U (en) * | 2017-08-03 | 2018-06-19 | 苏州瑞光电子科技股份有限公司 | LED light emission drive circuits |
-
2017
- 2017-08-03 CN CN201710655562.3A patent/CN107277982A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101106852A (en) * | 2007-06-25 | 2008-01-16 | 四川大学 | Current constant and light adjusting control circuit for luminescent LED array |
| CN102970803A (en) * | 2012-12-05 | 2013-03-13 | 成都芯源系统有限公司 | Apparatus and method for driving multiple strings of light emitting diodes |
| CN204721658U (en) * | 2015-05-25 | 2015-10-21 | 延锋伟世通电子科技（南京）有限公司 | With the automobile multiple constant current LED illumination circuit of temperature detection |
| CN207518896U (en) * | 2017-08-03 | 2018-06-19 | 苏州瑞光电子科技股份有限公司 | LED light emission drive circuits |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109377940A (en) * | 2018-11-22 | 2019-02-22 | 北京双竞科技有限公司 | A kind of LED display character driving circuit of Auto-matching section brightness |
| CN112287630A (en) * | 2019-07-09 | 2021-01-29 | 苏州市悠越电子有限公司 | Method for improving resistance value of inner loop of keyboard and optimizing layout of printed circuit |
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