CHROMAFILTER
INFORMATION
GUIDE

PLASTIC CONTRAST ENHANCEMENT LIGHT FILTERS FOR DISPLAYS

Eliminate Glare, Maintain High Resolution and Improve Viewing Contrast

CHROMAFILTER® thermoplastic filters are ideal for enhancing the readability of various optoelectronic/video displays. Chromafilter® products are transparent clear, neutral density gray, red, blue, green or amber flat plastic substrates, which have been surface treated with PCI Lab’s patented coatings,to produce abrasion and chemical resistant displays, while eliminating glare and maintaining high resolution. The neutral gray and colored Chromafilter® materials provide optimum contrast enhancement for all types of energy­ emitting and transmissive displays. Chromafilter® standard sheets are available in polycarbonate or acrylic substrates in thicknesses from .030″ (.76 mm) to .125″ [3.18 mm).

Chromafilter® products are used to enhance the readability of all types of optoelectronic and video displays. Chromafilter® sheets reduce glare for non-energy-emitting displays such as backlit LCDs.

Neutral gray Chromafilter® materials are used additionally to improve display contrast by reducing the light transmitted from the unit portion of the display devices as in white phosphor or full-color CRT monitors, vacuum fluorescent, plasma, LED, and EL displays.(Fig. 1)

Colored Chromafilter® with light transmission properties matched to the spectral energy output of the display device itself, make characters stand out in vividcontrast on the non-reflective surface. Ambient light, which would otherwise be reflected from the display, is absorbed as it passes through the filter and back again providing contrast enhancement. The Vueguard® 901 AG front-surface anti-glare coating dramaticallyreduces specular reflection (Fig. 2).

A unique Anti-Newton Ring rear surface treatment may be used to cancel annoying Newton interference patterns developed when plastic surfaces come in contact.

Both emmissive and non-emissive display technologies employ colored Chromafilter® products.

Transmission Curves for Neutral Gray Chromafilters
Energy Distribution for typical Red LED Display

TRANSMISIION CURVES

and X, Y, Z Coordinates for Standard Chromafilter® Materials

Transmission Curves for Chromafilters

The transmission curves are obtained using a Beckman DB-G Grating Spectrophotometer. The X, Y, Z coordinates are established in accordance with the CIE 1976 USCV Chromaticity diagram, Source C.

Transmission curves and X, Y, Z values are nominal and are to be used as design guidelines only (not to be used for specification and reference). Curves are for 54 gloss units.

chromafilter chart
contrast enhancement filters

Note 1: Specifying the Optimum Chromafilter® Gloss to Suit the Display Type.

In general, Vacuum Fluorescent and Liquid Crystal Displays should utilize higher gloss Chromafilter® than other types of displays to maintain high character resolution. For these displays, a nominal gloss of 75 units should be specified. Other displays normally
employ standard gloss Chromafilter® with a nominal gloss of 54 units.

Note 2: Custom Colored Sheets.

For displays requiring transparent colors other than the standards listed above, PCI color-matching laboratory can provide sample chips for your approval. For small sheet quantities, the approved color can be produced as a Chromafilter® acrylic substrate. Larger quantity sheet requirements can be furnished in polycarbonate as well as acrylic substrates.

OPTICAL COATINGS FOR DISPLAYS

VueGuard 901®

This high-performance family of UV-curable coatings provide exceptional resistance to abrasion and chemical attack. This front surface treatment provides superior mechanical, chemical and environmental properties, while maintaining excellent resolution. Inks and adhesives should be tested for their ability to adhere to the chemical-resistant coating.

VueGuard 901® AG

PCI Labs offers this coating in different finishes. The 901® AG treatment provides an anti-glare finish offered at various gloss levels, designed to reduce unwanted glare and coherent reflection, thereby increasing readability.

Amount of Glare Reduction Gloss Units (Nominall) 60° Gloss Meter
Very Light >85 gloss units
Light 75 gloss units
Standard 54 gloss units
Low 32 gloss units
Very Low 10 gloss units
Extra Low
<5 gloss units

VueGuard 901® WC

A high-gloss, water-clear finish, resembling polished glass, The VueGuard 901® WC resists chemical attack and steel-abrasion. This treatment is used when glare is not a problem and optimum resolution is important.

VueGuard 901® ANR

This unique Anti-Newton ring treatment is offered for applications where the rear surface of the Chromafilter® is in direct contact with the front of the display. Its use eliminates annoying Newton interference patterns, while offering good physical and chemical properties.

VueGuard 801®

This super hard UV-curable, optical clear coating is available as a Water-Clear [WC] treatment for plastic sheets, offering superior resistance to scratching and abrasion. This surface treatment is not machinable.

PRODUCT SPECIFICATIONS

Product Specifications

Optical Properties

Resolution

The resolution of the Chromafilter® 901 AG materials are such that, at 54 gloss units, the observer will resolve not less than 28 line pairs/ mm, ANSI/HRS 100-1988 and ISO 9241-3 standards at a specified distance between the target and Chromafilter® surface is 1.5″(38mm.)The anti-reflection property of Chromafilter® surface is defined as the measure of the front surface mirror reflection with a reflectometer or spectrophotomer with readings of less than 1%.

Gloss

Gloss is the visual impression, resulting from the surface evaluation of specular and luminous reflectance. The more uniform the light is scattered, the less intense the reflection in the main direction and the surface will appear duller. The degree of matte surface finish may be defined and measured by using a 60° gloss meter as specified in ASTM D-523-78 and ASTM D-2457. In general, there is a trade-off between gloss and resolution. When the display employs very fine character elements, such as a .3 mm CRT display, then a higher gloss is required on the filter.

This is also generally true for vacuum, fluorescent and liquid crys­tal displays, where the characters are spaced behind the front of the display element itself. Normally, a gloss of 75 +/- 6 units should be specified for these applications.

LED, gas discharge, plasma and monochrome CRT displays normally use 54 +/- 6 units of gloss on the Chromafilter® materials.

Scratch Resistance – Rotary Steel Wool Test

This test represents severe scratching using a 1.25 sq.-in. #0000 steel wool pad. The steel wool pad is loaded with appropriate weights to provide 24 psi and rotated for 100 cycles. The results of the testing are reported as haze change measured using ASTM D-1003.

Rotary Steel Wool Test Results(1) Haze Change
Material Treatment 100 REV
Acrylic, Untreated 31.1
Acrylic, Vueguard 901WC(1) 0.4
Polycarbonate, Untreated 28.1
Polycarbonate, Vueguard 901WC (1) 0.4

1. For anti-glare treatments, the haze is reduced.

Chemical Resistance

The chemical resistance testing was performed using a method far more rigorous than ASTM D-1308, spot test, covered. In the ASTM test, volatile liquids tend to evaporate rather rapidly, thus shortening the true exposure time. The tests reported here were performed by exposing the specimen to continuous contact with reagents by means of a wick or pad in the mouth of an inverted bottleplaced onto the specimen.

Chemical Resistance(2), (3), (4) Uncoated Coated
Gasoline X M
Toluene X S
Acetone X S
Ethanol L L
Trichloroethylene X S
5% Ammonia S S
10% Caustic Soda S S
50% Caustic Soda X S
10% Sulfuric Acid                                                L L

2. Chemical Resistance: Similar to ASTM 0-1308 but more severe.
Evaporation minimized through continuous contact with reagent by means
of a pad in the mouth of an inverted bottle placed on the specimen

3. L-Long-term contact, greater than 24 hours
    M- Medium-term contact, up to 8 hours
    S-Short Term contact, up to 1 hour
    X-lmmediate attack: do not use

4. Polycarbonate Test Data

Uncoated Thermal Properties and Flammability Ratings

Substrate Continuous Use Temp UL Flammablity Rating
Polycarbonate -45°C to 93°C
(-50°F to 200°F)
94V-2
Acrylic -40c to 71°C
(-40°F to 160°F)
94 HB

Display Readout Windows

In addition to supplying Chromafilter® materials in sheet form, PCI Labs can provide fully fabricated Display Windows, ready to install,with the optimum clarity and readability. Chromafilter® colors have been carefully developed to match or complement the spectral energy outputs of every type of optoelectronic display, thus providing maximum contrast. The viewing surface of the windows is treated with an abrasion and chemical resistant hardcoat which serves to eliminate annoying glare from incident light, while protecting the substrate surface.

EMC Display Filters

PCI Labs offers Electromagnetic Compatability (EMC) Display Filters in PMMA ensuring the optimum balance between light transmission and reduction of electromagnetic interference below levels disruptive to the proper operation of optoelectronic systems.

A complete range of contrast enhancement filters with embedded metal wire mesh are offered, to further attenuate electromagnetic fields and provide excellent shielding effectiveness.

Fully Fabricated/Printed Display Windows

Performance Coatings International is a vertically integrated manufacturing facility. Finished, fabricated, and graphic printed displays, ready to install, are provided using the Chromafilter® substrates with the front surface treatment specified.

Manufacturing capabilities include:

• CNC High Speed, Precision Cutting
• Shearing
• Punching/Blanking (Die-Cut)
• Steel Rule Die Cut
• CNC Routing/Drilling

Printed Graphics

Display Readout Windows and Instrument Displays may incorporate legends, symbols, or logos. When they are required, PCI Labs screen prints on the front or rear surface of the displays.

Background Borders and Masks

A single readout window may be used over several separated displays. A background mask can be screen printed on the rear of the window material to hide all areas between the displays. For aesthetic or mechanical design reasons, it is often desirable to use a window of larger dimensions than the display itself, with a rear screen printed border, to leave only the display visible.

Mounting Adhesive Tapes

Display windows are often installed with pressure sensitive adhesive tape. PCI Labs can provide parts with the adhesive tape applied, ready for installation.

Recommended Cleaning Instructions

The Chromafilter® surface treatment is impervious to most conventional cleaning agents. To clean, a non-abrasive cloth or paper wipe should be employed with any of the following:

• Window cleaners
• Mild detergent
• Ammonia and water
• Propanol

Cosmetic

The cosmetic acceptance criteria for Chromafilter® standard materials are detailed in PCI Labs Quality Assurance Procedure QAP-1354.

HOW TO ORDER

Chromafilter® materials are offered either in sheet form or as fully fabricated windows. For those users planning to fabricate or otherwise process the sheets, a protective low-adhesion, easily removable masking is provided on both sides.

To order, specify:

– Color
– Material
– Thickness
– Sheet Size
– Gloss or Water Clear Surface Treatment
– Masking