Monochrome LCD displays have been the popular choice in electronics industry for decades. Mono LCD displays offer cost-effective and reliable solution for displaying information in variety applications, such as industrial control panels, medical equipment, and consumer electronics. In this article, we will explore the basics of monochrome lcd displays, their applications, and benefits they offer. We will also discuss the various types of monochrome LCD displays available in the market and their features. Monochrome LCD displays are also popular in custom making displays, because of its cheaper tooling fee for custom displays.
1. What is a Monochrome LCD Display?
A monochrome LCD display is a type of display that uses a single color to display information. Monochrome LCD displays typically use black or dark gray pixels on a light-colored background to create images or text.
Monochrome LCD displays are common used in applications where color is not necessary, and a simple display is sufficient. They offer several benefits over color displays, including lower cost, lower power consumption, and better readability in bright light conditions.
2. Why we need the Monochrome LCD Displays
There are many benefits by using monochrome LCD displays for electronic devices. Benefits are included:
Low Cost: Monochrome LCD displays are typically less cost than color displays, making them an ideal choice for cost-sensitive applications.
Low Power Consumption: Monochrome LCD displays consume less power than color displays, making them ideal for battery-powered devices or applications where power consumption is a concern.
Better Readability in sunlight: By using transflective technology on LCD polarizers, monochrome LCD displays are easier to read in bright light conditions than color displays in transmissive TFT. Monochrome LCD also offer better contrast under sunlight, making them ideal for displaying text or simple icons or graphics by economy way than transflective tft LCD technology.
Simple interface: Monochrome LCDs have less pixels and resolution than color TFT display, it is easy to be driven by simple interface with less I/O ports, such as IIC interface, 3-wires / 4-wires SPI, 6 bits/8 bits parallel interface. The simple interface could decrease I/O ports of MCU in economy way.
Long Lifetime: Monochrome LCD displays have a long lifetime, 50k hours typically, up to 10K hours lifetime, making them a reliable choice for applications that require long-term use.
Low cost in customization: Monochrome LCD display can be custom LCD display, custom LCD could meet specific requirements for particular application. Monochrome LCDs can be made in various sizes, resolutions, aspect ratios, and abnormal shape in much lower tooling cost than TFT LCD displays.
3. Disadvantages of Monochrome LCD Displays
There are some disadvantages for monochrome LCD.
Less color: Mono LCD can not display images in full colors, the background is monochrome color with one color such as only white, or black, blue, gray color. The display color is only mono color, sometimes, by silk printing technology, it can be 4 multi-colors for TN, stn lcd in Maximum.
Low resolution: a monochrome LCD is mainly by using TN and STN LCD technology, the maximum resolution is up to 240 lines maximum. That is 320*240 pixels, or 640*240 pixels (except monochrome TFT).
Lower contrast than TFT displays: except monochrome TFT LCD, because monochrome TN LCD and STN LCD have cross-talk effect inside LCD cell, the contrast of monochrome LCD is lower than color TFT LCD panel.
4. Types of Monochrome LCD Displays
There are several types of monochrome LCD display technologies are available.
4.1. Upon display technologies, the display types include:
TN LCD Displays: TN LCD (Twisted Nematic, twisted angle: 90°) offer a fast response time and low power consumption, low cost, However, they have limited viewing angles and color reproduction.
HTN LCD Displays: HTN LCD(High-Temperature Nematic,twisted angle: 110°) offer a wider viewing angle than TN LCD displays, making them ideal for applications that require wider viewing angle than TN display, lower power consumption.
STN LCD Displays: STN LCD(Super-Twisted Nematic,twisted angle: 240°) offer high contrast and low power consumption, wider viewing angle than TN and HTN LCD, STN LCD offer more display contents for characters or graphic display, However, STN LCD also have limited color reproduction.
FSTN LCD Displays: FSTN LCD(Film Compensated Super-Twisted Nematic), a kind of STN lcd, because of film compensation, FSTN offer better viewing angles and color reproduction than STN LCD displays. FSTN LCD is black-white display with more similar to E-paper display.
VA TN LCD displays: VA TN LCD provide super wide viewing angle and high contrast than TN and STN LCD. It has black background with white display content, backlight is necessary for VA TN LCD module.
Monochrome TFT LCD: Monochrome TFT LCD is a kind of TFT LCD technology, but it is without color filter on the tft panel, there is thin film transistor on each pixel to open or close the pixel on and off, because no crass-talk influence, TFT LCDs have much better contrast than TN or STN LCDs. Monochrome TFT LCD could be made in high resolution that up to 4k or 8k resolution, The disadvantage of monochrome TFTs is the cost is costly and very high tooling fee. Therefore, monochrome TFT is mainly used on particular application, such as projector, 3D printer.
4.2. Upon configuration, monochrome LCD displays include:
LCD panel: LCD panel is the LCD glass without IC driver and backlight, the structure is only LCD glass and polarizers. It is the simplest structure of LCD display. Customer could use the LCD panel connected to their master board that has been combined LCD driver on the master board. The LCD panel connection ways have conductive rubber stripe, metal pins, and flex cable by ZIF connection or soldering way.
COB LCD module: COB LCD module means driver IC Chip on PCB board, the LCD panel is connected to driving PCB by conductive rubber stripe, the conductive rubber stripe and LCD are fixed by metal frame and PCB, while LCD drivers are located on the rear side of PCB.
COG LCD module:Driver IC Chip on LCD glass technology.
The advantage of COG LCD module: COG LCD module is cheaper than corresponding COB LCD module, because its structure is simple. The COG IC driving chip is bonded on the LCD glass, no need PCB board, metal frame.
Therefore, COG LCD module is thinner than COB LCD module due to no needing PCB board.
On the other hand, the unit cost of COG LCD module is also cheaper than corresponding COB LCD module, because its structure is simple than COB module, with less components and production processes, that means lower cost for the products.
The IC driver of COG LCD is connected to LCD glass by ACF (Anisotropic Conductive Film) tape, the golden particles in ACF tape provide better connection reliability than COB LCD module.
Disadvantage: the NRE tooling fee of COG LCD is much expensive than COB LCD module.
COF LCD module: Driver Chip on flexible film. The COF technology is fitting for the device that with strictly space limited, because COF LCD module is thinner than COB LCD, COF IC is not on the LCD glass, it is on the thin film with less room in the device.
Monochrome touch LCD screen: Monochrome LCD could be made with touch screen, as the familiar ways, either resistive touch panel or capacitive touch panel could be added on the top layer of LCD panel or LCD module. The inner touch technology could be made for monochrome LCD touch screen, the inner touch is also a kind of capacitive touch technology, the touch function is realized on some key points as button function, the key touch screen of monochrome LCD is the most economy way for touch screen LCD.
4.3. Upon display content, monochrome LCD displays include:
Segment LCD modules:
A seven segment LCD display is like the below picture, it can display numbers from 0 to 9 and several letters such as C, A, b E, L, and F by control some segments "on" and "off". it is the cheapest LCD display panel.
The segment LCD also could be in icon LCD display, that is the display content are included custom icons based on customer's application. Each segment means one icon, we could design the icon's shape and pattern based on our application.
Character LCD modules:
The familiar Characters LCD modules have 16x1, 16x2, 16x4 characters, 20x1, 20x2, 20x4 characters, and 40x2, 40x4 etc., characters LCD display module. A 16x2 LCD display means 16 characters x 2 lines character on the LCD. Normally, each character is made by 5x8 pixels, Character LCDs could display numbers 1~9, and A~Z letters, most characters have 5x8 pixels on each character.
Graphic LCD module:
The familiar graphic LCD resolutions have 96x64 pixels、96x96、 122x32、128x64、128x128、160x128、160x160、192x64、240x64、240x128、320x240 etc. it could display characters and image in the graphic LCD display. Of course, the higher resolution LCD, the display effect of image would be looked better.
5. Applications of Monochrome LCD Displays
Monochrome LCD displays are used in wide range of applications, including:
- Industrial control panels, Test and measurement equipment, Cash registers and POS machines
- Consumer electronics, such as digital watches and calculators, and other handheld devices.
- Automotive displays and medical equipment, Appliances, such as microwaves and ovens.
6. How can we get Monochrome LCD Displays:
6.1. Choose the standard monochrome LCD module from reliable supplier.
If you need small quantity monochrome LCD display for your project, choose a standard monochrome LCD module would be a good choice, you could save the tooling fee by choosing standard LCDs, Maclight have wide range standard Characters LCDs and Graphic LCD modules, including COB LCDs and COG LCD modules for your choosing, please visit Maclight website(www.szmaclight.com) or simply contact us at [email protected] for more details.
6.2. Custom make monochrome LCD for your project
The things we need to concern before custom making mono LCD
displays:
First, we need to make a design for the custom LCD, we need to
confirm some necessary information for custom LCD:
1. Outline
dimensions: Confirm the sizes what you would like to custom
making, the custom mono LCD displays would be mainly less than 10", the
custom sizes is up to the mother glass of LCD panels that is less than
14"x16". The custom mono LCD can be custom made in random sizes
below 10".
2. Color:
The color of the custom LCD display, the monochrome LCDs have difference
colors, such as blue mode, yellow-green mode, gray mode.
3. Display
content: it can be segment display or graphic display. The
graphic display can be up to 240 rows and 480 columns in maximum.
4. IC
driver: With or without IC driver.
5. LCD
connection way and interface: such as LCD pins connect to
master PCB by flex cable, metal pins, or conductive rubber stripe. If with IC
driver on the LCD module, the LCD module interface can be IIC, SPI, 6 bits/
8bits parallel interface.
6. Viewing
direction: TN and STN LCDs have limited viewing angle, so
we have to choose the best viewing direction for monochrome LCDs. If wide
viewing angle is necessary, we suggest VA TN LCD technology and DFSTN
technologies.
7. Backlight: With
or without the backlight, if choose the displays mode in transmissive LCD
or transflective lcd, backlight is essential parts of LCD display.
A counter drawing would be created upon upper characters by
designer or LCD manufacturer, after drawing approval by customer, LCD
manufacturer would make tooling mould for the custom LCD, the tooling fee
of moulds are difference based on the configuration of the custom LCD module.
Finally, the custom LCD displays would be produced in LCD factory.
If it is LCD panel, the custom LCD panel would be made in LCD panel factory
only, if it is LCD module with driver, backlight, FPC, touch components, the
custom LCD displays would be made in LCD module factory.
6.3. The tooling fee for custom making
monochrome LCD display.
The tooling fee of custom-make mono LCD panel would be a
few hundred dollars, if only simple segment LCD panel, such as TN display mode,
the tooling fee would be cheaper, but if the custom LCD screen is
monochrome graphic LCD panel, such as STN display panel, the tooling fee would
be little higher than TN LCD panel. Because the tooling mask for STN LCD would
be costly than TN LCD panel. it is the tooling fee for monochrome LCD panel
only.
If we need to custom make monochrome LCD module with
IC chip on glass(COG LCD module), the tooling fee would be higher than
only LCD panel, because if for custom TN or STN LCD panel, the
tooling mask can be made by PI film, while for custom COG LCD module, the
custom COG LCD tooling mask would be made by metal mask, so its tooling fee is
much higher, it would be upper to thousand of dollars.
Besides the custom LCD panel, for some custom LCD mode
that in transmissive LCD or transflective LCD display mode, because LCD
panel is passive display, different to OLED display panel, LCD panel can not
emit light by itself, it have to work with backlight, the backlight tooling fee
would be upper than 1000 USD, the more complicating structure on the backlight,
the tooling fee would be more. For saving the cost of tooling fee on LCD
backlight, the backlight with simple flat structure would be cheaper.
6.4. Concerning MOQ when in custom making
monochrome LCD:
The MOQ of custom LCD display for monochrome LCD is calculated
based on the mother-glass of LCD panel, some person may ask, what is
mother-glass of LCD panel? is it the mother of LCD panel? no, no,no..., it is
just a joke, the mother-glass of LCD is the primary glass of LCD, we also call
it ITO glass, because it has an ITO layer on the glass. LCD panels are
arrayed on the mother glass in manufacturing LCD panel, and cutting it one by
one after LCD cell production finished. The main mother glass sizes if
14"x16", as in LCD manufacturing, for stable running in the full-auto
machine line, it is at least 50 set of 14"x16" for an production
running, that is the smaller sizes of LCD, the bigger MOQ of LCD quantity is
necessary.
6.5. What is lead time for custom making
monochrome LCD in Maclight?
The lead time for custom LCD would be 3~5 working days for counter
drawing, after counter drawing approval from customer, lead time would
be 2 weeks only for tooling samples of LCD panel, if the solution is COG LCD
(chip on glass) or COB LCD module (chip on board), the samples lead time would
be 2~3 weeks for COG IC bonding and final assembly.
Part of standard monochrome LCD modules from Maclight : (click the picture to check more)
Maclight
Display is profession in custom making mono LCD displays, if you need
monochrome LCD or custom LCD displays, please contact us at [email protected].
