LCM (LCD Module) Introduction
LCD module is a liquid crystal display devices , connectors , integrated circuits , PCB circuit board , backlight, structural pieces fitting together components. English name called "LCD Module", referred to as "LCM", Chinese generally known as " liquid crystal display module ."
Liquid crystal display device is a high-tech base components , although its application Pat is very broad, but for many people, the use , still find it difficult to assembly. Especially the dot matrix liquid crystal display device , the user is unable to start feel . Connections and special equipment is required to understand and who have a non-human , a liquid crystal display device of the user therefore want someone do it , and control the liquid crystal display device , the driver IC mounted together to form a feature , the user can with the traditional process can be assembled into a whole system .
First, the digital display LCD module
It is assembled from a segment type liquid crystal display device integral with a dedicated integrated circuit features , only some of the identification numbers and symbols displayed . Segment type liquid crystal display devices are mostly used in the portable, pocket-sized device . Because of these devices are small, so as not to display the portion designed as a separate part , even though some applications require a separate display unit , it should also be in addition to a display function , but also has some of the information received, processed, storage transfer functions, because they have some kind of generic, specific functions and welcomed by the market. Common digital display LCD module are the following.
1 . Counting Module
This is a different digit seven-segment liquid crystal display drive and decoder , or assembled together with the count of the counter display unit . It has a record, process, display digital functions. Currently our main products on the market can be seen there by the CD4055 decoder drive unit driven liquid crystal display modules, as well as by the ICM72ll, ICM7231, ICM7232, CDl4543, UPDl45001, HD44100 , such as integrated circuits and corresponding sets of liquid crystal display devices are assembled into the 4 , 6 , 8 , 10 , 12 , 16 counting module . In the selection of such a counter module must note the following:
Understand the function: Although called " counter module ", but most of them can not be directly counted. They are just some of the input port interface forms BCD code , BCD code plus some strobe terminal input interface forms , there is a direct serial , parallel port interface contact forms , etc., such as the need to calculate or record a serial number, you must also configure the circuit , of course, there will be counting circuit with good news product module.
Look for structure: liquid crystal display has a different installation method and mounting structure. This solid, in the selection should pay attention to its structural features , in general, most of these counting module zebra conductive rubber , plastic ( or metal ) press box and PCB board with integrated liquid crystal display devices are assembled together . Lead solder type outer end there , plug pin , pin board style several.
Note Power supply: one device should try to use a unified power , the common liquid crystal display module with a single count -and dual power supply type , there are different specifications 5V and 9V .
2 . Measurement Module
This is a section of a number of liquid crystal display device having the decoding drive count , the integrated circuit chip A / D conversion function of the assembled module . Because of having an integrated circuit used in A / D conversion , the analog electrical signal may be inputted into the digital display. We know that any physical , chemical or even quantity ( such as pH , etc. ) can be converted to an analog power, so long as accompanied by certain sensors, such modules can be achieved towers and displays the amount of any money , very convenient to use . Metering module used in integrated circuit models are ICL7106, ICL7116, ICL7126, ICL7136, ICL7135, ICL7129 , these integrated features, characteristics determine the functions and features of metering module. As a measurement products, must be measured according to the provisions of identification . Metering department approved products posted a measurement certificate .
3 . Timing module
Timing module for liquid crystal display timing oldest history , a liquid crystal display device with a timer integrated circuit is assembled together a fully functional timer. It does not sound finished watches in the shell, so called timing module . Although the timing module is widely used, but common , standard timekeeping module is difficult to buy in the market , only to electronic timepiece manufacturers to buy or order the appropriate form the core , although the timing module and counting module similar in appearance , but they have different display, digital timing module displays a set of two by two groups of numbers. The figures are counting module for each successive order. As many timing module also has a timer , control functions, so these modules can be fitted to a wide range of some of the added power devices such as tape recorders , CD players , microwave ovens, rice cookers and other appliances.
Second, the character dot matrix LCD module
It is composed of dot matrix character LCD display and a dedicated row, column drivers, controllers, and the necessary connectors, assembled the structure , you can display numbers and Latin characters . This module itself has character dot matrix character generator , display capacity, feature-rich. Usually this type of module can display at least more than 8 or 16 l Line 1 line character . The module is arranged in matrix by a bundle of 5 × 7,5 × 8 pixels , or 5 × 11 matrix arrangement thereof. Each of a , a bit between each interval between each line is a line interval , it can not display graphics , the specifications are as follows:
8 ( a line ; line 2) 16 ( 1 row ; two rows ; row 4 ) 20 ( 1 row ; two rows ; 4 rows )
24 ( 1 line ; 2 lines ; 4 lines ) 32 ( 1 line ; 2 lines ; 4 lines ) 40 ( 1 line ; 2 lines ; 4 lines )
Generally in the module control , the drive has been cured of a good 192 -character font character library CGROM, but also allows users to custom build with special characters in random access memory CGRAM, allowing users to create 8 5 × 8 dot matrix characters.
Third, the dot matrix graphics LCD module
The module is also a module matrix , which matrix is characterized by continuous pixels arranged in rows and columns are not arranged in an empty compartment . So you can display a continuous , full graphics. Since it is also a XY matrix of pixels , so in addition to display graphics , you can also display characters.
1 row, column -driven
This is a must add special controller module , which is only equipped with a universal module row, column drive, this drive is actually only the pixel generally drive output , while the input to only four of the following data input , shift signal input terminal , the latch input terminal , the AC signal input terminal , etc. , such as HD44100, IID66100 so on. Such modules must be external control circuits, such as HD61830, SEDl330 etc. connected to the computer . The largest number of module types , the most common. Although the need to use self-made controller, but it also gives the customer can choose to leave the different controllers freedom.
2 . Row , column drivers - controlled
This is a direct interface with the computer , relying on the computer to control the drive module. Column driver has used this type of module I / O bus data interface module can be directly linked to the computer's bus , eliminating the need for dedicated controller, so the whole system cost reduction benefits . For the small number of pixels , the machine features small, computer software programming and very familiar with the user very applicable. But it will take some of the resources of your system.
3 . Row, column control type
This is a type of bitmap graphics controller module built . One type is more popular . This module is provided with only the first type such as row , column drivers , and the like are assembled like a dedicated controller T6963C . This controller is the interface between the liquid crystal driver from the computer , which in the most simple way controlled by the computer , the computer receives the various information and feedback , through their independent information processing to achieve the management of the display buffer , the drive shaft to provide all the required signal pulses , operating the drive module implements display . This controller has its own special set of instructions , and have their own character generator CGROM. Users must be familiar with the detailed description of this controller can be summarized as . This module allows the user to get rid of the controller design , processing, production and a series of work , and also allows the computer to avoid the cumbersome controls the display , saving the internal resources of the host system.