CN204836689U

CN204836689U - LED lamp plate

Info

Publication number: CN204836689U
Application number: CN201520564432.5U
Authority: CN
Inventors: 梁伟; 刘德福; 王伙荣
Original assignee: Xian Novastar Electronic Technology Co Ltd
Current assignee: Xian Novastar Electronic Technology Co Ltd
Priority date: 2015-07-30
Filing date: 2015-07-30
Publication date: 2015-12-02
Anticipated expiration: 2025-07-30

Abstract

The utility model relates to a LED lamp plate, including going scanning circuit, select switch circuit, many column rules, many alignments, LED array, display driver circuit and a plurality of capable discharge circuits of going, the scanning circuit that goes passes through to go select switch circuit electricity and connects many column rules, LED array electricity is connected many column rules with many alignments, display driver circuit electricity is connected many alignments, a plurality of capable discharge circuits electricity are respectively connected many column rules. Wherein, each line discharge circuit is the triode circuit. The utility model discloses an use the triode to put up capable discharge circuit, on the basis of not using extra control signal, reach LED lamp point effect out of control when letting out electricity elimination twilight sunset and preventing the reverse breakdown column rule parasitic capacitance fast.

Description

LED lamp panel

Technical field

The utility model relates to technical field of LED display, particularly a kind of circuit design of LED lamp panel.

Background technology

As shown in Figure 1, it is the structural representation of a kind of LED lamp panel of the prior art.Particularly, LED lamp panel comprises line-scan circuit 11, row selecting switch circuit 12, display driver circuit 13, many lines, many alignments, the LED array 15 being electrically connected described many lines and described many alignments and the multiple row discharge circuits 17 be electrically connected respectively with described many lines.Wherein, line-scan circuit 11 is electrically connected described many lines by row selecting switch circuit 12, and row selecting switch circuit 12 electric connection of power supply voltage VCC and comprise multiple PMOS to be electrically connected respectively with described many lines; Described many alignments of multiple current output terminal mouth electrical connection of display driver circuit 13; The anode of each the LED point in LED array 15 is electrically connected one of described many lines and cathodic electricity connects one of described many alignments; Each row discharge circuit 17 comprises and is serially connected in resistance between corresponding line and earthing potential GND and Zener diode.

Due to traditional LED lamp panel in actual applications, obviously can see there is faint twilight sunset above oblique line when beating oblique line, affecting display effect; Cause occurring that the reason of this phenomenon has a lot, its chief reason is that the line of LED lamp panel exists certain parasitic capacitance over the ground, when the current output terminal mouth of display driver circuit 13 is closed, control PMOS conducting, although can not lightening LED lamp point, but can charge to parasitic capacitance, when parasitic capacitance is filled with a certain amount of electricity, control PMOS is ended, this current output terminal mouth starting display driver circuit 13 sucks electric current, then parasitic capacitance is discharged by LED point forward, thus formation weak current causes LED appearance secretly bright.And the object that LED lamp panel shown in Fig. 1 increases row discharge circuit 17 is exactly electric discharge in order to increase parasitic capacitance/let out electric speed, thus eliminate the above-mentioned secretly bright afterglow issues caused.

Technical scheme shown in Fig. 1 has certain effect on twilight sunset is eliminated, but due to the non-ideal characteristic of Zener diode, time on certain current output terminal mouth of display driver circuit 13, in the several LED points connected in parallel there is reverse breakdown in certain LED, the effect of row discharge circuit 17 relative at this current output terminal mouth resistance in parallel to earthing potential GND, at this moment other LED points of all parallel connections can form loop by this resistance, even if close this current output terminal mouth also can there is electric current and flow through, thus cause LED point Chang Liang.

Refer to Fig. 2, it is the structural representation of another kind of LED lamp panel of the prior art.The structure of LED lamp panel shown in Fig. 2 is substantially identical with the LED lamp panel structure shown in Fig. 1, and difference is: Fig. 2 utilizes the combination of 74HC245 chip and inverter as row discharge circuit 27.Particularly, input/output end port B0 ~ the Bm of 74HC245 chip is electrically connected many lines respectively, input/output end port A0 ~ Am is electrically connected to earthing potential GND, direction controlling port DIR electric connection of power supply voltage VCC, output enable port G is electrically connected the output of inverter, and the latch signal LE in the input of inverter electrical connection display driver circuit.

In Fig. 2 using latch signal LE as electric discharge blanking signal use, LE be latched as high in line is discharged, but due to by 74HC245 chip discharge also can be uncontrollable due to discharging current, discharge excessive and cause LED point reverse breakdown.

Utility model content

Therefore, for defect of the prior art and deficiency, the utility model proposes a kind of LED lamp panel.

Particularly, a kind of LED lamp panel that the utility model embodiment proposes, comprise: line-scan circuit, row selecting switch circuit, many lines, many alignments, LED array, display driver circuit and multiple row discharge circuits, described line-scan circuit is by described many lines of described row selecting switch circuit electrical connection, described LED array described many lines of electrical connection and described many alignments, described many alignments of described display driver circuit electrical connection, described multiple row discharge circuit is electrically connected described many lines respectively.Wherein, row discharge circuit described in each is transistor circuit.

In an embodiment of the present utility model, described line-scan circuit comprises decoder, and multiple row selection signal outputs of described decoder are electrically connected described many lines and respectively respectively by pull-up resistor electric connection of power supply voltage.

In an embodiment of the present utility model, described row selecting switch circuit is electrically connected described supply voltage and comprises multiple PMOS, and described multiple PMOS is electrically connected described many lines respectively.

In an embodiment of the present utility model, described display driver circuit comprises constant-current source drive chip, and multiple constant current output ends of described constant-current source drive chip are electrically connected described many alignments respectively.

In an embodiment of the present utility model, described LED array comprises redness, green and blue led lamp point.

In an embodiment of the present utility model, described transistor circuit comprises triode, the first resistance, the second resistance and the 3rd resistance, described first resistance and described second resistance are serially connected between supply voltage and reference potential, one of described many lines of emitter electrical connection of described triode, the base stage of described triode is electrically connected to the node between described first resistance and described second resistance, and described 3rd resistance is connected electrically between the collector electrode of described triode and described reference potential.

As from the foregoing, the utility model embodiment builds row discharge circuit (or claiming blanking circuit) by using triode, on the basis not using extra control signal, reach and fast the effect that when electricity is eliminated twilight sunset and prevents reverse breakdown, LED point is out of control is let out to line parasitic capacitance.

By the detailed description below with reference to accompanying drawing, other side of the present utility model and feature become obvious.But it should be known that this accompanying drawing is only the object design of explanation, instead of as the restriction of scope of the present utility model, this is because it should with reference to additional claim.Should also be appreciated that, unless otherwise noted, unnecessaryly draw accompanying drawing to scale, they only try hard to structure described herein and flow process are described conceptually.

Accompanying drawing explanation

Below in conjunction with accompanying drawing, embodiment of the present utility model is described in detail.

Fig. 1 is the structural representation of a kind of LED lamp panel of prior art.

Fig. 2 is the structural representation of the another kind of LED lamp panel of prior art.

Fig. 3 is the structural representation of a kind of LED lamp panel of the utility model embodiment.

A kind of electrical block diagram that Fig. 4 is line-scan circuit shown in Fig. 3.

Fig. 5 is a kind of electrical block diagram of the discharge circuit of row shown in Fig. 3.

Embodiment

For enabling above-mentioned purpose of the present utility model, feature and advantage become apparent more, are described in detail embodiment of the present utility model below in conjunction with accompanying drawing.

Refer to Fig. 3, a kind of LED lamp panel that the utility model embodiment proposes comprises: line-scan circuit 31, row selecting switch circuit 32, display driver circuit 33, many line L1 ~ Lm, many alignment C1 ~ Cn, LED array 35 and multiple row discharge circuit 371 ~ 37m; These circuit elements are arranged on a printed circuit.

Wherein, line-scan circuit 31 is electrically connected described many line L1 ~ Lm by row selecting switch circuit 32, row selecting switch circuit 32 electric connection of power supply voltage VCC and comprise multiple switch element such as PMOS, each PMOS in row selecting switch circuit 32 is electrically connected described many line L1 ~ Lm respectively.Multiple current output terminal mouths of display driver circuit 33 are electrically connected described many alignment C1 ~ Cn respectively.LED array 35 is electrically connected described many line L1 ~ Lm and described many alignment C1 ~ Cn, and comprises multiple LED point such as red (R), green (G), blue (B) LED point; The anode of each LED point is electrically connected one of many line L1 ~ Lm and cathodic electricity connects one of many alignment C1 ~ Cn.Row discharge circuit 371 ~ 37m is electrically connected described many line L1 ~ Lm respectively.

Refer to Fig. 4, line-scan circuit 31 specifically can comprise decoder, such as 3-8 decoder or 4-16 decoder etc.Wherein, decoder has multiple row address signal input and row selection signal output the power supply termination supply voltage VCC of decoder and by electric capacity C1 ground connection, the earth terminal GND ground connection of decoder; The row selection signal output of decoder the grid (control end) of the corresponding PMOS in electrical connection row selecting switch circuit 32 and respectively by pull-up resistor R ₀~ R _jbe electrically connected to supply voltage VCC.

Refer to Fig. 5, row discharge circuit such as 37m is transistor circuit, and it specifically can comprise triode Qm and resistance R _l1, R _l2and R _l3.Wherein, resistance R _l1and R _l2be serially connected between supply voltage VCC and earthing potential (reference potential); The emitter electrical connection line Lm of triode Qm, collector electrode is by resistance R _l3ground connection, base stage is electrically connected to resistance R _l1and R _l2between node.

Below in conjunction with Fig. 3, Fig. 4 and Fig. 5, the operation principle of the LED lamp panel of the utility model embodiment is described:

In line-scan circuit 31, row address signal (or claiming sweep signal) is through Encoder driving decoding choice for traveling signal, row selection signal controls the switch of the power supply of corresponding LED point by the conducting or cut-off controlling PMOS, and the output signal of the constant current output end of itself and the constant-current source drive chip in display driver circuit 33 such as MBI5025 family chip controls the display of corresponding LED point together.

When a certain PMOS in row selecting switch circuit 32 is by row selection signal conducting, such as Lm is selected for corresponding line, and the LED point be connected on line Lm normally shows; Afterwards when PMOS cut-off, line Lm and supply voltage VCC disconnects, the voltage disconnected on moment line Lm is still VCC, triode Qm such as PNP pipe in row discharge circuit 37m is in magnifying state, thus electric current repid discharge, the electric charge on line Lm is released, when voltage on line Lm is less than or equal to the base voltage of triode Qm, triode Qm ends, and electric charge no longer lets out electricity, thus avoids LED point reverse breakdown.

In sum, the utility model embodiment builds row discharge circuit (or claiming blanking circuit) by using triode, on the basis not using extra control signal, reach and fast the effect that when electricity is eliminated twilight sunset and prevents reverse breakdown, LED point is out of control is let out to line parasitic capacitance.

Finally; it is worth mentioning that; the function of the transistor circuit 37m in above-described embodiment of the present utility model utilizes triode to be in magnifying state to realize letting out electricity fast and utilizing the automatic cut-off of triode to prevent LED point reverse breakdown; therefore those skilled in the art can carry out suitable change to the element in transistor circuit 37m under the prerequisite meeting described function, and the transistor circuit after these changes all should be included in protection range of the present utility model.

So far, apply specific case herein and set forth the principle of LED lamp panel of the present utility model and execution mode, the explanation of above embodiment just understands method of the present utility model and core concept thereof for helping; Simultaneously; for one of ordinary skill in the art; according to thought of the present utility model; all will change in specific embodiments and applications; in sum; this description should not be construed as restriction of the present utility model, and protection range of the present utility model should be as the criterion with appended claim.

Claims

1. a LED lamp panel, comprise: line-scan circuit, row selecting switch circuit, many lines, many alignments, LED array, display driver circuit and multiple row discharge circuits, described line-scan circuit is by described many lines of described row selecting switch circuit electrical connection, described LED array described many lines of electrical connection and described many alignments, described many alignments of described display driver circuit electrical connection, described multiple row discharge circuit is electrically connected described many lines respectively; It is characterized in that, row discharge circuit described in each is transistor circuit.

2. LED lamp panel as claimed in claim 1, it is characterized in that, described line-scan circuit comprises decoder, and multiple row selection signal outputs of described decoder are electrically connected described many lines and respectively respectively by pull-up resistor electric connection of power supply voltage.

3. LED lamp panel as claimed in claim 2, it is characterized in that, described row selecting switch circuit is electrically connected described supply voltage and comprises multiple PMOS, and described multiple PMOS is electrically connected described many lines respectively.

4. LED lamp panel as claimed in claim 1, described display driver circuit comprises constant-current source drive chip, and multiple constant current output ends of described constant-current source drive chip are electrically connected described many alignments respectively.

5. LED lamp panel as claimed in claim 1, it is characterized in that, described LED array comprises redness, green and blue led lamp point.

6. the LED lamp panel as described in claim 1 to 5 any one, it is characterized in that, described transistor circuit comprises triode, the first resistance, the second resistance and the 3rd resistance, described first resistance and described second resistance are serially connected between supply voltage and reference potential, one of described many lines of emitter electrical connection of described triode, the base stage of described triode is electrically connected to the node between described first resistance and described second resistance, and described 3rd resistance is connected electrically between the collector electrode of described triode and described reference potential.