Round Tip Display Films
Manufacturer's part number :
Luminit Round-Tip Display (RTD) Film is designed to increase the brightness of displays by making use of refracted and reflected light to recycle otherwise wasted light and direct more light toward the viewer. The RTD film can provide a brightness gain of 30% to 40% in a display. The round tips are more rugged than sharp tip prisms which can break off in use causing contamination in the display. The Round-Tip pattern is embossed on a 10 mil polycarbonate substrate which has higher temperature durability when compared to polyester films. The RTD film is available with or without an integrated diffuser on the back. The combined RTD film and diffuser reduces the number of films in the display stack. The RTD film is typically used in a display stack with the first RTD film with diffuser on the bottom facing the light source, and a second RTD film without a diffuser oriented crosswise to the bottom layer with a cover sheet and the LCD panel on top. Other brightness enhancement films may be used in conjunction with the RTD films, typically between the top RTD film and the cover sheet.
View our wide range of Light Shaping Diffusers
View our portfolio of Photonics
See all products from our supplier Luminit
Technical Data :
Quote and availability
Ask our experts
- RTD film can provide a brightness gain of 30% to 40% in a display.
Lighting in direct view - Reduce hot spot
Format option capabilities
General view of light shaping diffusers
Beam angle capabilities
Ask our team of experts
Read our FAQs below, and submit your own.
New question? Ask the team
What are Light Shaping Diffusers?
Light Shaping Diffusers are a micro-structures pseudo randomly embedded on a substrate (such as film). When applied to a lighting structure, the Light Shaping Diffuser can manipulate light by changing the direction of its energy, allowing it to clean up and shape a light beam to suit a particular purpose.
Where are LSDs used?
LSDs are often applied in architectural lighting, can lights, decorative lighting, pool lighting, set/event lighting and wall wash lighting where the effects of LSDs can be quite dramatic. LSDs are also used in illumination systems such as aircraft inspection lights
What sizes of LSDs are available?
Thin film LSDs are available in rolls, sheets or parts cut to your specifications. Standard rolls are 508mm wide and 150m long. Strip rolls are also available in your specified width.
Are LSDs available for smaller applications?
Yes, Luminit LSDs are available in various circular and elliptical angles in pre-cut sheet format for lower volume applications.
What angles are available?
LSDs are available in a variety of circular and elliptical angles from 1° to 80° on thin film or rigid substrates.
What is the transmission efficiency of Luminit LSDs?
The transmission efficiencies of Luminit LSDs are rated between 85-92% (depending on the angle). This very high efficiency rating is due to the fact that the technology is based on diffractive microstructures. Smaller angle diffusers have the highest transmission.
Is the angle of diffusion and transmission wavelength dependent?
Since the microstructures are random and non-periodic, the LSD is not wavelength dependent, so it works well from 400nm to 1500nm.
Can LSDs reduce hotspots with LED lights?
Yes, Luminit LSDs eliminate the hotspots without a significant reduction in the amount of the light, provided that the diffuser is placed a sufficient distance from the LEDs. A rule of thumb is that the diffuser must be at least as far away from the LEDs as the LEDs are spaced apart.
Can LSDs shape light beams?
Yes, Luminit LSD are so precise that beam shaping is possible. A patented holographic master recording process allows a variety of circular and elliptical light patterns. Standard circular angles range from 0.5° to 80° FWHM. A wide variety of standard elliptical angles, ranging from 10° x 0.2° to 95° x 35°, are available.
What does FWHM mean?
FWHM is an abbreviation for Full-Width Half-Maximum, which is the angle of diffusion that would be seen after a collimated laser passes through the diffuser.
How long does an LSD last?
For indoor applications, an LSD would last as long as the light structure. For outdoor applications, measures may need to be taken to prevent a yellowing of the film due to exposure to the sun. For outdoor lighting applications, Luminit offers an optional UV-stable substrate to help prevent yellowing.
Should I face the diffuser towards or away from the light source?
The diffuser has improved transmission characteristics if the microstructure side is facing the light source, but it has better source hiding characteristics if the microstructure side is facing away from the light source.
How should I handle the diffuser and can I clean it if it gets dirty?
Handle the diffuser with clean latex gloves. High angle diffusers are very prone to damage due the height of the microstructures. They can be cleaned carefully using optical wipes and ethanol using the industry-standard "drop and drag" technique.
How do I mount the diffuser in my system?
We recommend you find a mechanical means of securing the diffuser into your system, for example using the natural tension of a film on curved surface. Luminit offer pressure sensitive adhesive (PSA) as an option but this process is difficult and you may experience the incorporation of air bubbles during the lamination process.
Does the LSD’s angle of diffusion or transmission change if I use a thicker LSD diffuser?
No, since the technology is based on a surface relief pattern, these parameters are not dependent on the thickness of the substrate. However, there are inherently additional transmission losses if very thick substrates are utilised (Beer’s Law).
What is the effective working distance of the diffuser to eliminate hotspots under direct view?
This depends on the angle of divergence and spacing of the light sources. With 110° Field of View, surface mount LEDs, the relationship is around 1:1. That is, if the LEDs are spaced 1 inch apart then you will need a little more than 1 inch distance from the LEDs to our largest diffuser angles.
How can I determine which angle will work for me?
We can offer a sample page with 9 samples about 1 inch square as well as larger A4 sized sheets of select single angles on 0.010 inch thick polycarbonate. Contact us for more information.
Can the LSD diffuser replace a secondary optic?
No, an LSD cannot decrease the divergence of a light source, it can only increase its angle of divergence.
What is a DTF?
Luminit’s DTF (Direction Turning Film) is a non-symmetrical linear micro-prismatic that imparts a 20° shift in the angle of a semi-collimated light source. The DTF works well with LED light sources that utilise secondary optics. Some applications include recessed can lights to allow for more wall washing, pathway/stair lighting to reduce glare and increase ground illumination, and pool lighting to increase illumination of the bottom.
How do DTFs work with LSDs?
Direction Turning Films can be combined with Light Shaping Diffusers to shape and homogenize the beam in addition to changing the direction. The beam can be shaped in a circular or elliptical pattern dependent on the diffuser angle chosen. These light bending films enable off-axis placement of the incoming beam when direct line of sight is impractical. Applications include LED lighting, avionics displays, traffic signs/displays and LCD backlights. They are also used to change the light beam direction to light a wall, walkway or other lighting target.
Can we model the diffuser in optical software?
Yes, we can provide BTDF data. Contact us for more information.
How linear is the transmission and diffusion angle with drive signal?
The diffusivity has a natural "sigmoidal" (ie "S" curve) response to drive signal strength.
What angles of diffusion can I achieve?
You can achieve a range of angles from 1° FWHM in the clear state to 70° FWHM in the fully diffused state.
What is the transmission of the EVD-M?
The EVD unit has an 81% transmission efficiency in the "on" state and 78% in the "off" state measured at 550nm at 28°C. Anti-reflection coated glass laminates are available on a special order basis to improve transmission.
What can I do with an Electronically Variable Diffuser?
The EVD unit is useful in dynamically and precisely adjusting the beam divergence of a collimated or semi-collimated light source. Typical applications include bio-photonics and bio-chemical research, neutral density filtering, detector sensitivity control, and optical characterisation of materials.
How is the EVD-M powered?
The EVD-M is powered by a RoHS compliant wall transformer that accepts 100 to 240 volts AC and transforms it to 9 volts DC for the EVD-M. It uses up to 100mA of current at 9 volts.
Over what temperature range can EVDs operate?
EVDs can operate at temperatures from 10°C to 55°C.
How do I clean the EVM-M?
The special liquid crystal in the aperture of the EVD-M can be cleaned with a conventional compressed gas spray duster. Oils and other more adherent contaminants can be removed with the "drop and drag" cleaning technique using an isopropyl alcohol moistened optical lens tissue.