CN202996251U

CN202996251U - Liquid crystal color display control circuit and air conditioner

Info

Publication number: CN202996251U
Application number: CN 201220629365
Authority: CN
Inventors: 李秉樵; 郑绪成; 陈建昌
Original assignee: Guangdong Midea Refrigeration Equipment Co Ltd
Current assignee: GD Midea Air Conditioning Equipment Co Ltd
Priority date: 2012-11-23
Filing date: 2012-11-23
Publication date: 2013-06-12
Anticipated expiration: 2022-11-23

Abstract

The utility model is suitable for the field of display control, and provides a liquid crystal color display control circuit and an air conditioner. The utility model eliminates the special color liquid crystal management chip of high cost, and adopts an MCU control unit of chip price to realize the driving of liquid crystal color display; public output ends, segment code control output ends and color control output ends of the MCU control unit are synchronously output through a synchronous conversion circuit, and each segment code polling is displayed in color. Since the segment code polls are switched quickly, the segment codes appear to be continuously displayed from the user's perspective. In concrete implementation, the synchronous conversion circuit can be an operational amplifier or an analog-to-digital converter arranged in the universal MCU, and the synchronous clock signals can be obtained by means of software; and the synchronous conversion circuit can also be a physical circuit arranged outside the MCU control unit. No matter which means is adopted, the MCU control unit is a mature product and has low price.

Description

A kind of color liquid crystal display control circuit and air conditioner

Technical field

The utility model belongs to the demonstration control field, relates in particular to a kind of color liquid crystal display control circuit and air conditioner.

Background technology

on the display screen scheme of all kinds of household electrical appliances, the liquid crystal display of adopting at present is generally the black-and-white crystal display mode, non-dot matrix color liquid crystal is the development trend in this field cheaply, but present non-dot matrix color liquid crystal generally adopts modular manner, utilize special-purpose colour display tube reason chip, its connected mode is as shown in Figure 1: MCU is by communication interface and the communications of Special colored liquid crystal managing chip such as SPI, the color liquid crystal managing chip is according to receiving the idsplay order that MCU sends, drive liquid crystal respective field is shown, drive simultaneously the color of backlight output liquid crystal display field.Although effect is pretty good, but because the color liquid crystal managing chip is specific customization, on the high side, in some low-end products, only need simple non-dot matrix chromatic liquid crystal screen, the segment encode quantity that this series products need to show is few, need the color of demonstration also few, adopt color LCD module if basic 8 kinds of color relations can meet the demands, if adopt special-purpose color liquid crystal managing chip, can increase cost of products.

The utility model content

In view of the above problems, the purpose of this utility model is to provide a kind of color liquid crystal display control circuit, is intended to solve in the colored displaying scheme of available liquid crystal the technical matters that needs the higher Special colored liquid crystal managing chip of cost, increased production cost.

in order to solve the technical problem, the color liquid crystal display control circuit that the utility model provides, comprise the black-and-white crystal plate, be located at the color backlights of described black-and-white crystal plate bottom and the MCU control module that drives described black-and-white crystal plate and color backlights, described color backlights comprises a kind of color LED lamp of color at least, the color LED lamp of described every kind of color all is connected to the color control output end of described MCU control module by synchronous drive circuit, the public output of described MCU control module and segment encode control output end correspondence are connected to common port and the segment encode control end of described black-and-white crystal plate, as improvement, described color liquid crystal display control circuit also comprises: what be connected with the public output of described MCU control module synchronizes change-over circuit, be used for changing the output waveform of described MCU control module public output, obtain synchronizing clock signals, control segment encode control output end and the color control output end of described MCU control module and refresh simultaneously output.

The utility model also provides a kind of air conditioner that comprises above-mentioned color liquid crystal display control circuit.

The beneficial effects of the utility model are: technical solutions of the utility model have been saved the color liquid crystal managing chip of the higher special use of cost, realizing driving color liquid crystal with low-cost MCU control module shows, by a synchronous change-over circuit, synchronously export the public output of MCU control module, segment encode control output end and color control output end, and each segment encode poll is colored to be shown.Because the switching of segment encode poll is very fast, the user seems that each segment encode shows continuously, and during specific implementation, described synchronous change-over circuit can for being built in operational amplifier or the analog to digital converter in general MCU, obtain synchronizing clock signals by software mode; Also can be for being placed on the entity circuit of MCU control module.No matter adopt which kind of mode, described MCU control module is all matured product, and price is lower.

Description of drawings

Fig. 1 is existing color LCD module control circuit figure;

Fig. 2 is the circuit structure diagram of the color liquid crystal display control circuit that provides of the utility model embodiment;

Fig. 3 is the second circuit structure diagram of the color liquid crystal display control circuit that provides of the utility model embodiment;

Fig. 4 is color liquid crystal displaying principle schematic diagram;

Fig. 5 is the field schematic diagram of each segment encode on the black-and-white crystal plate;

Fig. 6 is the circuit structure diagram of synchronous drive circuit in the color backlights that provides of the utility model embodiment;

Fig. 7 is the first exemplary circuit structural drawing of synchronous change-over circuit;

Fig. 8 is the second exemplary circuit structural drawing of synchronous change-over circuit;

Fig. 9 is the third exemplary circuit structural drawing of synchronous change-over circuit;

Figure 10 is the synchronizing signal conversion timing sequence figure of above-mentioned three kinds of synchronous change-over circuits;

Figure 11 is the control chart of the colored backlight sequential that provides of the utility model embodiment;

Figure 12 is the another kind of synchronizing signal conversion timing sequence figure of synchronous change-over circuit.

Embodiment

In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explaining the utility model, and be not used in restriction the utility model.

Fig. 2 shows the circuit structure of the color liquid crystal display control circuit that the utility model embodiment provides, and for convenience of explanation, only shows the part relevant to the utility model embodiment.Referring to Fig. 2:

the color liquid crystal display control circuit that the present embodiment provides, comprise black-and-white crystal plate 1, be located at the color backlights 2 of described black-and-white crystal plate 1 bottom and the MCU control module 3 that drives described black-and-white crystal plate 1 and color backlights 2, described color backlights 2 comprises a kind of color LED lamp 21 of color at least, the color LED lamp 21 of described every kind of color all is connected with synchronous drive circuit 22, the input end of described synchronous drive circuit 22 is connected to the color control output end of described MCU control module 3, the public output of described MCU control module 3 and segment encode control output end correspondence are connected to common port and the segment encode control end of described black-and-white crystal plate 1,

As improvement, described color liquid crystal display control circuit also comprises: what be connected with the public output of described MCU control module 3 synchronizes change-over circuit 4, be used for changing described MCU control module 3 public outputs output waveform, obtain an effective synchronizing clock signals, control segment encode control output end and the color control output end of described MCU control module 3 and refresh simultaneously output.

In the utility model embodiment, increase by one be connected with the public output COM of MCU control module 3 synchronize change-over circuit 4, be used for changing described MCU control module 3 public output COM output waveform, obtain an effective synchronizing clock signals CLK-IN(rising edge/negative edge), control segment encode control output end and the color control output end of described MCU control module 3 and refresh simultaneously output.

When specific implementation, synchronous change-over circuit 4 can be divided into two large classes: a class is the circuit that is placed on MCU control module 3, as shown in Figure 2; Another kind of being built in described MCU control module 3 also is connected with public output COM, is generally by operational amplifier or analog to digital converter, obtains synchronizing clock signals CLK-IN by software mode, as shown in Figure 3.

In order to make the segment encode color show evenly, with reference to Fig. 4, described color backlights 2 also comprises light guide plate 23, the bottom of described light guide plate 23 is provided with diffuse reflector 24, described color LED lamp 21 is positioned at described light guide plate 23 1 sides, the light that colored electric lamp bulb 21 sends reflects in light guide plate 23, after through diffuse reflector 24 reflections, versicolor light is fully mixed, is radiated at equably on the black-and-white crystal screen, mix light and emit from effective field, finally form the color content that the user can see.

The black-and-white crystal plate 1 that the present embodiment provides includes common port and segment encode control end, suppose to have N common port, M segment encode control end, here N, M are natural number, the quantity of described common port is identical with the segment encode figure place that the black-and-white crystal plate can show, every next common port gating, the segment encode of M the current gating of segment encode control end control demonstrates concrete content, allow light to pass through when the segment encode demonstration is effective, if this moment, color backlights 2 sent colorama, just can demonstrate so colored content on black-and-white crystal plate 1.

Take Fig. 2 as example, in the black-and-white crystal plate 1 in figure, common port is 8, is respectively COM0 ~ COM7, and the segment encode control end is 7, is respectively SEGA ~ SEGG, and therefore, black-and-white crystal plate 1 can demonstrate 8 segment encodes, and each segment encode has 7 fields, as shown in Figure 5.Fig. 5 provides the field schematic diagram of each segment encode on black-and-white crystal plate 1, each segment encode is respectively by the corresponding gating of common port COM0 ~ COM7,7 fields of each segment encode are respectively A ~ F, when the segment encode control end SEGA ~ SEGG that is connected with described Related fields is loaded with effective voltage, this field effectively shows, can pass through light at this moment; If this moment, color backlights 2 was luminous, described field also can demonstrate corresponding color, goes out different fields by control display, can demonstrate corresponding colorful digital.Certainly described each segment encode can also have more or less field; such as the field that can also increase the expression radix point; can demonstrate the colorful digital of mixed decimal point like this, obviously the protection domain of the utility model embodiment does not limit the number of segment encode and the number of the field that each segment encode comprises.

In the present embodiment, described color backlights 2 comprises a kind of color LED lamp 21 of color at least, and this colored electric lamp bulb can be versicolor LED lamp.The corresponding a kind of color of each COM common port backlight, color backlight is synthetic according to the principle of true color (RGB).The performance of MCU control module 3 has determined the quantity of displayable backlight color, and take the LED lamp of 3 kinds of colors as example, minimum can show 8 kinds of color (RGB 1:1:1=2 ³That=8), performance is good can be 32768 kinds of (RGB 5:5:5=2 ¹⁵=32768) and 16777216 kinds of (RGB 8:8:8=2 ²⁴=16777216), or even more color.That is, suppose to have the colored electric lamp bulb of X kind color, luminous or extinguish according to controlling each color LED lamp so, have at least 2 ^XPlant color combination, the segment encode on the black-and-white crystal plate just can have 2 ^XPlant the selection that color shows.For Cost reduction, it is enough that common segment encode can demonstrate 8 kinds of colors, the colored electric lamp bulb that namely needs three kinds of colors, suppose to be respectively red light, green light and blue lamp, the color control output end of corresponding MCU control module 3 is just " LED-RED-OUT ", " LED-GREEN-OUT " and " LED-BLUE-OUT ", under the condition that the luminous intensity of the bulb of every kind of color is determined, 8 kinds of colors output combinations of color backlights output are also just decided, such as being respectively white, red, green, blue, Huang, pink, black, azure.

Can find out from foregoing description, public output COM and segment encode control output end SEG that described control module 3 needs except having black-and-white crystal plate 1 also need 1 synchronous clock input pin CLK_IN and 3 output pins (LED-RED-OUT, LED-GREEN-OUT and LED-BLUE-OUT) to be used for controlling color backlights 2.

when specific implementation, the structure of the synchronous drive circuit 22 in color backlights 2 can be as shown in Figure 6: with the color LED lamp 21(of every kind of color be red light here, green light and blue lamp) corresponding synchronous drive circuit 22, comprise respectively divider resistance R1, R2, R3 and NPN type triode, the base stage of NPN type triode meets respectively the color control output end LED-RED-OUT of described MCU control module 3, LED-GREEN-OUT and LED-BLUE-OUT, the collector of triode passes through respectively red LED, green LED, blue led and divider resistance R1, R2, R3 meets operating voltage VCC, the emitter of NPN type triode T is ground connection all.Adjust divider resistance Ry(and be R1, R2 and R3 here) size can adjust the light intensity of corresponding color LED lamp, the ON time of color LED lamp is controlled by LED-RED-OUT, LED-GREEN-OUT and LED-BLUE-OUT.

In the color liquid crystal display control circuit that the utility model provides, be mainly the output characteristics of utilizing the public output COM of MCU control module: the N of MCU control module public output COM is effective in turn, the order be T0 → T1 → T2 → ... → Tn-1 → T0, and effective time, T was identical.So, know T and beginning and ending time of one of them COM effective time, just can infer the beginning and ending time of next COM.For example, know effective start time of COM1, T is after second so, and COM2 begins effectively, and then T is after second, and COM3 begins effectively; Perhaps known effective concluding time of COM0, T is after second so, and COM1 effectively finishes, and then T is after second, and COM2 effectively finishes.The significant instant of all COM can be calculated out.

Below by the synchronous change-over circuits 4 of several concrete output waveforms that are used for conversion MCU control module 3 public output COM, the principle of work of the color liquid crystal display control circuit that the utility model is provided is carried out brief description.

Fig. 7 is the first exemplary circuit structural drawing of synchronous change-over circuit 22, comprise comparer A and B, the normal phase input end of described comparer A connects the first comparative voltage, the inverting input of described comparer B connects the second comparative voltage, the normal phase input end of the inverting input of described comparer A and comparer B is connected to the public output COM of described MCU control module 3, the output terminal of described two comparer A, B connects rear output synchronizing clock signals altogether to the synchronous clock input end CLK-IN of described MCU control module 3, is connected to operating voltage by pull-up resistor Rx simultaneously.

Fig. 8 is the second exemplary circuit structural drawing of synchronous change-over circuit 22, comprise comparer A, the normal phase input end of described comparer A connects the first comparative voltage, inverting input is connected to the public output COM of described MCU control module 3, the output terminal output synchronizing clock signals of described comparer A is to the synchronous clock input end CLK-IN of described MCU control module 3, and the output terminal of comparer A is connected to operating voltage by pull-up resistor Rx simultaneously.

Fig. 9 is the third exemplary circuit structural drawing of synchronous change-over circuit 22, comprise comparer A, the inverting input of described comparer A connects the second comparative voltage, normal phase input end is connected to the public output COM of described MCU control module 3, the output terminal output synchronizing clock signals of described comparer A is to the synchronous clock input end CLK-IN of described MCU control module 3, and the output terminal of comparer A is connected to operating voltage by pull-up resistor Rx simultaneously.

With reference to Fig. 7-Fig. 9, although it is different to form the components and parts of synchronous change-over circuit 22, the comparative voltage of input is also different, but effect is all the output waveform by the public output COM of conversion MCU control module 3, obtain an effective synchronizing clock signals CLK_IN(rising edge/negative edge), as shown in figure 10.Particularly, the synchronous change-over circuit 22 that above-mentioned Fig. 7-Fig. 9 provides, to the transformation result of the public output COM7 of MCU control module 3 as shown in following table one:

Table one

The effective time of CLK_IN	Beginning	Middle	Finish
				Fig. 7	Negative edge	/	Rising edge
Fig. 8	Negative edge	Rising edge	/
				Fig. 9	/	Negative edge	Rising edge

Concerning the MCU control module, synchronizing clock signals is to select rising edge or negative edge all to be fine, and key is the significant instant of CLK_IN in T7 and the method for the whole display timing generator of the anti-T0---T7 of pushing away.Concerning the MCU control module, synchronizing clock signals CLK_IN has 3 kinds in the sequential of T7: beginning, middle, end.As shown in following table two:

Table two

Take synchronous change-over circuit 22 shown in Figure 7 as example, when backlight comprises 3 backlights, be respectively: during red LED/green LED/blue led, adopt said method can extrapolate the sequential that refreshes backlight.The color that it can show such as following table three:

Table three

Effective common port	The display segment code pattern	Red backlight	The green colored backlights lamp	Blue backlight	Pattern color
						COM0	“0”	ON	ON	ON	White
COM1	“1”	OFF	OFF	OFF	Black
						COM2	“2”	ON	OFF	OFF	Red
COM3	“3”	OFF	ON	OFF	Green
						COM4	“4”	OFF	OFF	ON	Blue
COM5	“5”	OFF	ON	ON	Azure
						COM6	“6”	ON	OFF	ON	Pink
COM7	“7”	ON	ON	OFF	Yellow

What will indicate especially is, because black is light tight, so do not show.

When the synchronous drive circuit that adopts simultaneously as shown in Figure 6,3 output pins are controlled respectively switch situations red in backlight, green, blue 3 LED lamps, and the variation of color backlight as shown in figure 11.Synchronization only has 1 COM effective, and 8 COM are effective in turn.Corresponding liquid crystal segment encode demonstration is determined by SEG when some COM are effective.For example COM1 is effective, and SEGB=1, SEGC=1, other SEG are 0, liquid crystal display numeral " 1 ".And the color of liquid crystal is decided by the color LED lamp in backlight, corresponding LED-RED-OUT, LED-GREEN-OUT, LED-BLUE-OUT determine whether corresponding LED lights, for example: when COM2 is effective, LED-RED-OUT=1, " 2 " of a redness of demonstration; When COM3 is effective, LED-GREEN-OUT=1, " 3 " of a green of demonstration; In like manner, when COM5 is effective, LED-GREEN-OUT=1 and LED-BLUE-OUT=1, green LED lamp and blue led lamp are lighted simultaneously, show azure " 5 ".

Because the vision of eye has the stop effect, so what see is not that independent 0(is white), 1(is black) etc. image, a but figure as last in Fig. 9: 0(is white) 1(is black) 2(is red) 3(is green) 4(is blue) 5(is azure) 6(is pink) 7(is yellow) time demonstration.

In addition, of particular note: identical hardware circuit, by adjusting the ON time of backlight, can realize different color displays.Be for example peach demonstration equally, but adjust the ON time of backlight, make the ON time of red LED lamp and blue led lamp into different proportion, can present several different pink.

On the other hand, the voltage of the different corresponding invalidatings of display mode also can be different, and Figure 12 is exactly the another kind of synchronizing signal conversion timing sequence figure of synchronous change-over circuit, the i.e. another kind of output waveform of MCU control module public output COM.To the same waveform, comparative voltage is not unique; For the output waveform of different COM, the deviser can suitably adjust comparative voltage.The utility model includes but not limited to that several comparative voltages of occurring in accompanying drawing are to the drive form of black-and-white crystal plate, as long as effective voltage and dead voltage can be exported in the public output COM of MCU control module and color control output end, make the black-and-white crystal plate can show that corresponding contents gets final product.In addition, as another kind of embodiment, the present embodiment provides a kind of air conditioner, this air conditioner comprises described color liquid crystal display control circuit, can demonstrate the content of multiple color on the display interface of air conditioner, compare with the existing air conditioner of special-purpose color liquid crystal managing chip that adopts, reduced the production cost of air conditioner.

The above is only preferred embodiment of the present utility model, not in order to limit the utility model, although with reference to previous embodiment, the utility model has been carried out more detailed explanation, for a person skilled in the art, it still can be modified or part technical characterictic wherein is equal to replacement the technical scheme that aforementioned each embodiment puts down in writing.All any modifications of doing within spirit of the present utility model and principle, be equal to and replace and improvement etc., within all should being included in protection domain of the present utility model.

Claims

1. color liquid crystal display control circuit, comprise black-and-white crystal plate (1), be located at the color backlights (2) of described black-and-white crystal plate (1) bottom and drive described black-and-white crystal plate (1) and the MCU control module (3) of color backlights (2), described color backlights (2) comprises a kind of color LED lamp (21) of color at least, the color LED lamp of described every kind of color (21) all is connected to the color control output end of described MCU control module (3) by synchronous drive circuit (22), the public output of described MCU control module (3) and segment encode control output end correspondence are connected to common port and the segment encode control end of described black-and-white crystal plate (1), it is characterized in that, described color liquid crystal display control circuit also comprises: what be connected with the public output of described MCU control module (3) synchronizes change-over circuit (4), be used for changing the output waveform of described MCU control module (3) public output, obtain synchronizing clock signals, control segment encode control output end and the color control output end of described MCU control module (3) and refresh simultaneously output.

2. color liquid crystal display control circuit as claimed in claim 1, it is characterized in that, described synchronous change-over circuit (4) comprises two comparer (A, B), the normal phase input end of described comparer A connects the first comparative voltage, the inverting input of described comparer B connects the second comparative voltage, the normal phase input end of the inverting input of described comparer A and comparer B is connected to the public output of described MCU control module (3), described two comparer (A, B) output terminal connects rear output synchronizing clock signals altogether to the synchronous clock input end of described MCU control module (3), be connected to operating voltage by pull-up resistor Rx simultaneously.

3. color liquid crystal display control circuit as claimed in claim 1, it is characterized in that, described synchronous change-over circuit (4) comprises comparer A, the normal phase input end of described comparer A connects the first comparative voltage, inverting input is connected to the public output of described MCU control module (3), the output terminal output synchronizing clock signals of described comparer A is connected to operating voltage by pull-up resistor Rx simultaneously to the synchronous clock input end of described MCU control module (3).

4. color liquid crystal display control circuit as claimed in claim 1, it is characterized in that, described synchronous change-over circuit (4) comprises comparer A, the inverting input of described comparer A connects the second comparative voltage, normal phase input end is connected to the public output of described MCU control module (3), the output terminal output synchronizing clock signals of described comparer A is connected to operating voltage by pull-up resistor Rx simultaneously to the synchronous clock input end of described MCU control module (3).

5. color liquid crystal display control circuit as claimed in claim 1, is characterized in that, described synchronous change-over circuit (4) is built in described MCU control module (3), comprises operational amplifier or analog to digital converter.

6. color liquid crystal display control circuit as claimed in claim 1, is characterized in that, described color LED lamp (21) comprises red LED lamp, green LED lamp and blue led lamp.

7. color liquid crystal display control circuit as claimed in claim 6, it is characterized in that, the described synchronous drive circuit (22) corresponding with the color LED lamp (21) of every kind of color all comprises divider resistance Ry and NPN type triode, the base stage of described NPN type triode connects the color control output end of described MCU control module (3), the collector of described NPN type triode connects operating voltage by described color LED lamp (21) and divider resistance Ry successively, the grounded emitter of described NPN type triode.

8. an air conditioner, is characterized in that, described air conditioner comprises color liquid crystal display control circuit as described in claim 1-7 any one.