Transmissive: The transmissive liquid crystal cell does not have reflective properties. Utilizing a backlight behind the display creates the image that is displayed on the screen, and the transmissive liquid crystal cell acts as a light valve to either allow the light to pass through the display or to block the light. This technology is used when there are few ambient light sources available.
Transflective: Utilizing a transflector, which is a reflector that will still allow some light to pass through, transflective ...
A capacitive touch screen is constructed out of glass with a coating of capacitive material
electrodeposited over its surface. Oscillator circuits at the corners of the capacitive glass measure
the capacitance of a person touching the glass surface. Each oscillator will vary in frequency
according to where a person touches the surface. The touch screen controller measures the
frequency changes to determine the X and Y coordinates of the touch. The drawback is that
capacitive touch screen cannot be activated by any non-conductive material, including a ...
The four most common touch screen technologies are: resistive, infrared, capacitive, and SAW
(surface acoustic wave). Resistive and capacitive touch screen technologies are the most popular
for industrial and small format applications. If the application requires that operators wear gloves
when using the touch screen, then resistive is preferred over capacitive. Generally, capacitive
technology offers better optical and touch performance, including multiple touch, but is more
expensive than its resistive counterpart.
An LCD is nothing more than a light valve that either allows light to go through the display or
blocks the light from passing. To create a full-color display, each pixel is actually divided into
three rectangular sub-pixels. When combined, these three sub-pixels are dimensionally similar
to a typical square pixel. These sub-pixels are then aligned perfectly with an RGB color filter
that is printed into the LCD cell itself. The color filter is a repeating pattern of Red-Green-Blue
columns, with each color the width of ...
common drivers and segment drivers are the two unique types of driver ICs. common drivers
produce signals to create rows or numbers of lines. Segment drivers produce signals to create the
characters or columns.
The controller IC receives data written in ASCII or JIS code from the MPU. This data in stored
in RAM and is then converted into serial character patterns and transferred to the LCD driver IC.
The most commonly used in monochrome graphic and newer TFT LCD modules, the driver/controller IC receives data ...
Twisted Nematic (TN) was one of the earliest fluid types to be implemented in LCD displays. Twisted Nematic LCD fluid uses a 90-degree twist between the top and bottom alignment layers of the LCD cell. The contrast of TN fluid displays is very high, but the limitations are that TN fluid can only support a limited multiplex rate, or limited number of rows. These displays are ideal for low information content, like simple character, segmented, or icon-based displays, commonly found in ...
Segment LCD: In the most common format, the display segments are arranged to form a figure 8 to display numbers and letters. The same technology can be implemented to construct custom icons of any shape or pattern in an LCD display, as well.
Character Display: The individual pixel units are arranged in 5×7 or 5×8 clusters to form characters. These displays are then characterized by how many rows and columns of pixel clusters, or characters, they can support. For example a 2×16 ...
EL (Electroluminescent Lamp)
An EL backlight is a solid-state component, which uses colored phosphors to generate light.
These EL backlights are thin, lightweight, and provide very uniform lighting. EL panels are
available in a wide variety of colors. While their power consumption is moderately low, they
require voltages of 100 VAC @ 400 Hz supplied by an inverter that converts a 5, 12, or 24 VDC
input to the AC output. EL backlights also have a limited half-life of 3,000 to 5,000 hours. The
biggest drawbacks to ...
Backlights are the light-emissive components positioned behind the LCD cell. Backlights are a
part of all transmissive or transflective displays. When an LCD display is used in an environment
where the ambient lighting will not support good reflective-mode visibility, the backlight
luminance is required to give the display contrast and be legible. Backlights are also required
in almost all full-color TFT displays due to the inherently low efficiency of the transmissive
structure of the TFT cell.