CN212851109U

CN212851109U - Anti-flicker circuit in LED dynamic scanning

Info

Publication number: CN212851109U
Application number: CN202022012451.0U
Authority: CN
Inventors: 陈翔
Original assignee: China Key System and Integrated Circuit Co Ltd
Current assignee: China Key System and Integrated Circuit Co Ltd
Priority date: 2020-09-15
Filing date: 2020-09-15
Publication date: 2021-03-30
Anticipated expiration: 2030-09-15

Abstract

The utility model discloses a prevent scintillation circuit in LED dynamic scanning, including a plurality of LED lamps, the LED lamp includes first lamp L1, second lamp L2, fourth lamp L4, sixth lamp L6, seventh lamp L7, ninth lamp L9, and sixteenth lamp L16, first lamp L1, second lamp L2, fourth lamp L4, sixth lamp L6, seventh lamp L7, ninth lamp L9, and sixteenth lamp L16 are the LED lamp at same public end, and the public end is connected with the singlechip through COM4, the condition of adding the triode on not in hardware, public end through the software is virtual can be when certain LED lamp scintillation, avoid appearing the LED lamp and produce the light and shade and change, and can reduce certain cost.

Description

Anti-flicker circuit in LED dynamic scanning

Technical Field

The utility model relates to a LED dynamic scanning technical field specifically is an anti-flicker circuit among LED dynamic scanning.

Background

When a plurality of LEDs are displayed, each LED is in a unique row and column, and the dynamic scanning is to operate only the LEDs in the same row or column in a short time, and the LEDs in other rows or columns are turned off. The LED dynamic scan display is used in many electronic products. When the singlechip pin is used for driving the heavy-current LED to dynamically scan and display, the general maximum driving current of the singlechip pin cannot exceed 100ma, so when the LED is displayed in a scanning mode, the driving current is insufficient, the LEDs which can be controlled simultaneously can be arranged, and when some LEDs flicker, other LEDs which should be normally bright can also follow obvious brightness change.

At present, the common end of the LEDs which can be controlled simultaneously is a cathode and is connected with a triode, so that the common end can be directly connected to the ground by using the small driving current of a pin of a singlechip to drive the on-off of the diodes, the controllable differential pressure on each LED at the same time is constant, and the LED flicker can not be influenced by other LEDs, and the problems existing in the solution are as follows: firstly, a triode is required to be added to hardware, so that the cost is increased; secondly, the large current pin of the single chip microcomputer which originally meets the LED driving condition does not need large current actually, and resources are wasted.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an anti-flicker circuit among LED dynamic scan to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides a prevent scintillation circuit in LED dynamic scanning, includes a plurality of LED lamps, the LED lamp includes first lamp L1, second lamp L2, fourth lamp L4, sixth lamp L6, seventh lamp L7, ninth lamp L9, and sixteenth lamp L16, first lamp L1, second lamp L2, fourth lamp L4, sixth lamp L6, seventh lamp L7, ninth lamp L9, and sixteenth lamp L16 are the LED lamp at same common terminal, and the common terminal is connected with the singlechip through COM 4.

Preferably, one end of the first lamp L1, which is far away from the common end, is connected with the single chip microcomputer through a fifth interface SEG5, and one end of the second lamp L2, which is far away from the common end, is connected with the single chip microcomputer through a second interface SEG 2.

Preferably, one end of the fourth lamp L4, which is far away from the common end, is connected to the single chip microcomputer through a third interface SEG3, and one end of the sixth lamp L6, which is far away from the common end, is connected to the single chip microcomputer through a first interface SEG 1.

Preferably, one end of the seventh lamp L7, which is far away from the common end, is connected to the single chip microcomputer through a fourth interface SEG4, and one end of the ninth lamp L9, which is far away from the common end, is connected to the single chip microcomputer through a seventh interface SEG 7.

Preferably, one end of the sixteenth lamp L16 far away from the common end is connected with the single chip microcomputer through a sixth interface SEG 6.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the utility model discloses, pull down COM4 after COM4, COM5, COM6 again and pull down COM4, can increase 2 milliseconds on the basis of original scanning cycle 6 milliseconds again, handle sixth lamp L6 and go on and off the operation when COM4 was pulled down for the first time, other first lamp L1, second lamp L2, seventh lamp L7, fourth lamp L4, ninth lamp L9 and the sixteenth lamp L16 that are in same public end with sixth lamp L6 are in the go out state, handle other LEDs except sixth lamp L6 on the COM4 public end when COM4 is come for the second time. The sixth lamp L6 and other LEDs are processed in a time-sharing manner, so that the influence of the operation of the sixth lamp L6 on other LEDs can be avoided, and the condition that other LEDs are turned off in a dimming manner when the sixth lamp L6 is subjected to flicker processing can be avoided.

2. The utility model discloses, need not to increase the triode on hardware, can reduce cost.

Drawings

Fig. 1 is a far-away view of the LED circuit connection according to the embodiment of the present invention;

fig. 2 is a timing control diagram according to an embodiment of the present invention.

Detailed Description

In order to prevent the LEDs which need to be normally lighted from generating obvious brightness and darkness changes when certain LED lamps flicker, the anti-flicker circuit in the dynamic scanning of the LEDs is particularly provided. 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. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1

Referring to fig. 1-2, the present embodiment provides an anti-flicker circuit in LED dynamic scanning, including a plurality of LED lamps, where the LED lamps include a first lamp L1, a second lamp L2, a fourth lamp L4, a sixth lamp L6, a seventh lamp L7, a ninth lamp L9, and a sixteenth lamp L16, the first lamp L1, the second lamp L2, the fourth lamp L4, the sixth lamp L6, the seventh lamp L7, the ninth lamp L9, and the sixteenth lamp L16 are LED lamps at the same common end, and the common end is connected to a single chip microcomputer through COM 4.

One end of the first lamp L1, which is far away from the public end, is connected with the single chip microcomputer through a fifth interface SEG5, and one end of the second lamp L2, which is far away from the public end, is connected with the single chip microcomputer through a second interface SEG 2.

One end of the fourth lamp L4, which is far away from the common end, is connected with the single chip microcomputer through a third interface SEG3, and one end of the sixth lamp L6, which is far away from the common end, is connected with the single chip microcomputer through a first interface SEG 1.

One end of the seventh lamp L7, which is far away from the common end, is connected with the single chip microcomputer through a fourth interface SEG4, and one end of the ninth lamp L9, which is far away from the common end, is connected with the single chip microcomputer through a seventh interface SEG 7.

And one end of the sixteenth lamp L16, which is far away from the public end, is connected with the single chip microcomputer through a sixth interface SEG 6.

When controlling a plurality of LEDs, driving the LEDs to turn on and off may be divided into two types, i.e. a common cathode and a common anode, as shown in fig. 1, i.e. when the common terminal is at a low voltage, the SEG high and low levels of the corresponding LED lamps are operated to turn on and off, and when the dynamic scanning common terminal of the LEDs is determined, firstly, the blinking LEDs and the normally on LEDs on the same common terminal are respectively marked.

As shown in fig. 1, the sixth lamp L6, the first lamp L1, the second lamp L2, the seventh lamp L7, the fourth lamp L4, the ninth lamp L9, and the sixteenth lamp L16 are all LEDs on the same common terminal, the common terminal is COM4, and the cathode controlled by the LEDs is directly connected to the pin of the single chip microcomputer; the first interface SEG1, the fifth interface SEG5, the second interface SEG2, the fourth interface SEG4, the third interface SEG3, the seventh interface SEG7 and the sixth interface SEG6 are used as anodes controlled by LEDs and are also connected to pins of a single chip microcomputer, when the 7 LEDs are controlled, the COM4 level needs to be pulled down at regular time, then the level of an anode end corresponding to the LED needing to be controlled is pulled up or pulled down, and when other LEDs are controlled, the COM4 level needs to be pulled up.

The timing pull-down time of the level is generally millisecond level, because a plurality of public ends need to be dynamically scanned when a plurality of LEDs are generally controlled, assuming that the timing time is n milliseconds, a public end is provided in total, and the same public end is pulled down after every (a × n) milliseconds; as shown in fig. 1, if there are a common terminals and COM4 is one of the common terminals, the COM4 port is changed to low level every (a × n) milliseconds, where if the sixth light L6 flickers, the other LEDs are kept normally on, and if nothing is done, the other normally-on LEDs in the background art will change brightness and darkness when the sixth light L6 flickers.

A common end is virtually simulated on software, namely the LED lamps processed in the software correspond to (a +1) common ends, the sixth lamp L6 needing flicker processing is independently treated on a (a +1) port, namely the first lamp L1, the second lamp L2, the seventh lamp L7, the fourth lamp L4, the ninth lamp L9 and the sixteenth lamp L16 are subjected to COM4 level lowering processing in a certain n millisecond operation time sequence, and the sixth lamp L6 is in an off state in the time sequence; in another n-mm timing sequence, the first lamp L1, the second lamp L2, the seventh lamp L7, the fourth lamp L4, the ninth lamp L9 and the sixteenth lamp L16 are turned off, and the sixth lamp L6 is correspondingly turned off and dimmed, and the COM4 port is also pulled low.

The operation sequence is shown in fig. 2, that is, it is ensured that the LED which needs to blink and the LED which is located at the same common end and needs to be normally lit operate at different operation sequences, so that it can be ensured that the blinking LED causes the blinking phenomenon of other LEDs in the dynamic scanning.

Fig. 1 shows three common cathode terminals COM4, COM5 and COM6, which are respectively connected to a control pin of a single chip microcomputer, and SEG terminals of LEDs connected to the common terminals are also respectively connected to a control IO pin of the single chip microcomputer. When the SEG end is high, and the common port is low, LED is similar to the diode characteristic, switches on and give out light, because singlechip IO driving capability is limited to lead to inside supply current can appear the saturated condition when all LEDs are bright simultaneously, during this saturated condition, if there is LED to do the scintillation processing on the common port, current variation can appear in other LED, and LED bright light intensity can appear changing.

In fig. 1, the sixth lamp L6 needs to be turned on for 1 second and turned off for 1 second in function implementation, other lamps need to be turned on or turned off normally within a certain time, the single chip microcomputer sets a timer to perform 2-millisecond interruption, one of the three public terminals is pulled down in each interruption process, and then the corresponding SEG high-low level is operated to achieve the turning on and turning off of the corresponding LED.

In summary, COM4 is pulled down for 2 milliseconds within 6 milliseconds of a scanning period, and in the 2 milliseconds, the corresponding LEDs are turned on and off, and when the sixth light L6 is turned on and off, because the current at the COM4 end changes to some extent, the other first light L1, second light L2, seventh light L7, fourth light L4, ninth light L9 and sixteenth light L16, which are located at the same common end as the sixth light L6, are affected when the light is normally turned on, and change to some extent in darkness.

In this embodiment, the COM4 is pulled down again after the COM4, COM5 and COM6 are pulled down, that is, the original scanning period is increased by 2 milliseconds on the basis of 6 milliseconds, when the COM4 is pulled down for the first time, the sixth lamp L6 is turned on and off, other first lamp L1, second lamp L2, seventh lamp L7, fourth lamp L4, ninth lamp L9 and sixteenth lamp L16 which are at the same common end as the sixth lamp L6 are in an off state, and when the COM4 is received for the second time, other LEDs except the sixth lamp L6 at the COM4 common end are processed. The sixth lamp L6 and other LEDs are processed in a time-sharing mode, the influence of the sixth lamp L6 on other LEDs during working is avoided, and the situation that other LEDs are turned off in a dark mode cannot be caused when the sixth lamp L6 conducts flicker processing.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides an anti-flicker circuit in LED dynamic scanning, includes a plurality of LED lamps, its characterized in that: the LED lamps comprise a first lamp L1, a second lamp L2, a fourth lamp L4, a sixth lamp L6, a seventh lamp L7, a ninth lamp L9 and a sixteenth lamp L16, the first lamp L1, the second lamp L2, the fourth lamp L4, the sixth lamp L6, the seventh lamp L7, the ninth lamp L9 and the sixteenth lamp L16 are LED lamps at the same common end, and the common end is connected with a single chip microcomputer through COM 4.

2. The LED flicker prevention circuit in dynamic scanning of claim 1, wherein: one end of the first lamp L1, which is far away from the public end, is connected with the single chip microcomputer through a fifth interface SEG5, and one end of the second lamp L2, which is far away from the public end, is connected with the single chip microcomputer through a second interface SEG 2.

3. The LED flicker prevention circuit in dynamic scanning of claim 1, wherein: one end of the fourth lamp L4, which is far away from the common end, is connected with the single chip microcomputer through a third interface SEG3, and one end of the sixth lamp L6, which is far away from the common end, is connected with the single chip microcomputer through a first interface SEG 1.

4. The LED flicker prevention circuit in dynamic scanning of claim 1, wherein: one end of the seventh lamp L7, which is far away from the common end, is connected with the single chip microcomputer through a fourth interface SEG4, and one end of the ninth lamp L9, which is far away from the common end, is connected with the single chip microcomputer through a seventh interface SEG 7.

5. The LED flicker prevention circuit in dynamic scanning of claim 1, wherein: and one end of the sixteenth lamp L16, which is far away from the public end, is connected with the single chip microcomputer through a sixth interface SEG 6.