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| Custom glass |
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In cost sensitive applications such as utility meters (which require segments only or simple alphanumeric text), LCD glass only is the best solution, with the LCD driven directly from the host microprocessor/controller IC. For a small tooling charge, we can fully customize this LCD glass (size, image, temperature range etc.) to provide you with 100% satisfaction.
 Feasibility stage
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Technical Feasibility: We evaluate your specifications to determine whether or not the LCD can be manufactured. We can use either a basic outline or full specification. This stage is carried out by the UK engineering team
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QA feasibility: We evaluate your QC requirements and specifications to determine whether or not we can satisfy them. This may also include the customer test specification.
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Commercial Feasibility: We evaluate your specifications and requirements to determine whether the LCD can be manufactured within your budget. This stage is carried out by the UK and Far East offices. At this stage we also determine and agree with you the minimum order quantities and minimum production quantities.
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Design
stage
| | | Upon receipt of the tooling order we proceed with the design. Based on your specifications and results of the feasibility study, our engineering departments in the Far East will produce counter drawings and specifications. These drawing are checked and approved by our UK engineering team before being sent to you for approval. Counter drawings take from 1 to 3 weeks according to the complexity. |
Prototype
stage
| | | Once you formally approve the counter drawings, we proceed with the prototypes.
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| | | The prototypes take from 4 to 12 weeks according to the complexity of the design and the availability of the materials.
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| | | The prototypes are manufactured in the Far Eastern LCD factories. Before being sent to you, the prototypes are tested against the approved specification by both the UK engineering team and the Far Eastern engineering department.
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| | | At this stage we also review the current lead times and materials to determine whether or not the results of the feasibility study are still applicable.
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Production
stage
| | | Production can proceed once you have formally approved the prototypes.
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| | | The LCDs are manufactured to all approved specifications and all previously agreed specifications, e.g. test and QC specs. |
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Criteria
for custom glass quotation: |
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| | To ensure that our custom glass solution is the perfect match for your specific needs, and to ensure that we provide you with an accurate initial quotation, please make sure that you supply us with specific information about your requirements, as per the criteria below. If you need clarification of any kind, please consult our sales support team. It is their job to help you make the right decisions. The custom glass criteria are:
| | | | LCD technology |
| | | Overall Dimensions |
| | | LCD image |
| | | Polarisers |
| | | Display mode |
| | | Operating environment |
| | | Drive method |
| | | Connection method |
LCD
Technology
We need to know which of the following technologies best meets your custom glass requirements
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Twisted Nematic (TN)
TN is the simplest LCD technology. Common applications
include calculators, heating controllers and utility
meters. The LC twist angle is 90°, making this technology
ideal for simple "digit" or "icon" images, with
little or no need for multiplexing. Suitable for
mux. rates of 1:1 to 4:1. Typical temperature range:
-30°C to +85°C.
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First Minima TN (FMTN)
When the transmission of monochromatic light is
measured through a TN cell between parallel polarisers,
zero transmission occurs at several points, 1st
minima, 2nd minima, 3rd minima. In a positive mode
display, maximum contrast is achieved by selecting
the 1st minima point, hence the name First Minima
TN displays. Temperature range: -30°C to +85°C.
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Enhanced TN (ETN)
Designed for negative mode displays, using the higher
minima points with the higher cell gap to produce
a 'blacker' background. This technology originated
in the automotive industry where bright backlighting
makes a high "black value" - important for avoiding
bleed through of light in non selected areas.
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Super Twisted Nematic (STN)
As the multiplex rate of a display increases, the
voltage between the non selected and selected voltages
(Von/Voff) decreases. For drive schemes from static
through to 1/4 mux, this voltage difference is large
enough in a TN cell to maintain an acceptable contrast
level and avoid cross talk. However, multiplex drive
schemes from 1/8 to 1/480 mux require the steeper
electro optical characteristics of STN, which has
a slightly more limited temperature range (-30 to
+80°C) than TN due to its higher complexity.
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Overall
Dimensions
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We need to receive the exact measurements of your
custom glass requirements.
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LCD
Image
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We need to know what type of data imaging you
require on the display, e.g. 7 segment digits (6mm)
plus icons, alphanumeric dot matrix (5 x 7 dots
per character) or Graphics etc.
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Polarisers
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LCDs are constructed with three types of polariser
films: Transmissive, Reflective or Transflective.
Front surface polarisers are always transmissive.
Rear surface polarisers can be any of the three.
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Transmissive polarisers are used in low ambient
applications that require backlighting, and allow
maximum transmission of the backlight brightness.
The image is not viewable when the backlight is
not switched on.
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Reflective rear polarisers are used in applications
with no backlight, either because of insufficient
backlight power or because of high ambient light.
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Transflective rear polarisers combine transmissive
and reflective polarisers, which means that the
image can be viewed in high or low ambient light
when the backlight is switched on.
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Display
Modes
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Display modes are available in two options:
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Positive mode (dark characters on light background)
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Negative mode (light characters on dark background)
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Operating
Environment
| | | PWe need to know the precise details of the operating environment in which the display will be used. |
Drive
Method
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We need to know the multiplex rate (also known
as the duty.) For example: 1/4, 1/8 duty or 4 mux,
64 mux.
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Connection
Method
Connection methods are available in three options:
| | | Elastomeric Connection: Provides a low-cost, solderless, high density connection. In order to achieve the necessary compression (typically 10 to 15%), the glass will also require a bezel. Elastomeric is also known as Zebra strip.
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| | | Pin Connections: The pins are epoxy-bonded to the edge of the glass. Typical pitch is 2.54mm, but 1.80mm and 2.0mm also available.
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| | | Heatseal Connection (HSC): A foil of alternating conductive and insulating material is bonded by heat and pressure to the LCD to provide a highly reliable connection. The other end can be either bonded to a PCB or inserted into a suitable ZIF connector. |
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