Osram Opto ’s LED China visible light LED market manager Liang Zechun said: “Osram ’s excellent optical design and light contrast technology may one day play an important role in next-generation LED technology.”
Liang Zechun mentioned the importance of optical design at the LEDforum 2016 held by LEDinside in Taipei on September 30, 2016. He emphasized that optical design plays a very important role in several aspects.
Liang Zechun, Osram Opto's LED market manager for visible light LEDs in China (Image source: LEDinside)
To change the effect seen by the naked eye, the key to optical design is the distribution of light, and another core technology is to eliminate reflected light. In outdoor natural light or ambient light conditions, the human eye will also receive reflected light, which is why display manufacturers emphasize the brightness requirements of outdoor LED large screens to exceed 5,000nit or even 7000nit.
However, it is actually quite difficult to eliminate the interfering light by filtering the reflected light on the screen. At this time, optical design can come in handy. In various device applications, the direct output of light to the required angle is used to reduce the loss of light output and the impact caused by reflected light.
For example, LEDs may be able to help correct some display problems with micro lenses and optical design.
Liang Zechun also explained that Oval's Oval Optic designs can effectively overcome this problem without the need to add secondary optics to the SMD LED.
He said: "The main reason is that the horizontal angle needs to reach 120 degrees, but in practice it does not need to reach the same vertical angle of 120 degrees, which also indicates that it will cause waste in optics."
By using elliptical optical design, such as the Displix optical design package, the horizontal angle is controlled within 110 degrees, and the vertical angle is 60 degrees. It focuses the light to a specific area and reduces the cost of light output. In the case of vertical 60 degrees and horizontal 110 degrees, the error range of red light using oval optical design is very low in both horizontal and vertical directions, and its stability and consistency are maintained.
He pointed out that for different display applications, different lens angles should be adjusted. For example, common road information displays on highways require smaller 30-degree lens angles, but displays such as bus body information need wider 60-degree lens angle, bus stop signs and commercial advertising screens require a 120-degree viewing angle.
Manager Liang Zechun explained: "Basically, adding lenses to surface-mount devices has a total of 11 parameters that affect the light distribution; the results of optical design are also affected by the accuracy of the manufacturing process and the lens configuration. Details of each parameter.
Will the application of blackbody lighting contrast technology be incorporated into the future blueprint of next-generation LEDs?
In response to this new technology trend, OSRAM is also developing black-body LEDs. With the dark substrate of the LED, the area that reflects the surrounding light can be minimized and the light contrast can be improved to achieve improved light and color contrast and increased display performance. Reading effect.
This technology can be applied to LED indoor small pitch and LED outdoor large screen. The advantages of absorbing diffused light and reducing reflected direct sunlight can provide high contrast of the display screen and good visual color consistency, improving the playback effect of images and movies.
For example, placing the iPhone 6 and iPhone 5 in the sun at the same time and using the approximate black body SMD LED low-reflection display technology, the iPhone 6 can provide better image resolution and display than the control machine using traditional display technology. Effect, this is the difference between blackbody SMD LEDs.
In contrast, traditional display technologies have either insufficient light intensity in daylight, or their strong light can cause light damage at night. When the power is turned off, the display also appears mottled, and the picture quality is not satisfactory when playing video images.
This black-body backlight concept can be applied to LEDs that do not require a reflection cup and made into white LEDs. The reduction of white LEDs to 6 microns is equivalent to the size of an LED.
LEDs are suitable for indoor large, medium and small display screens; while black-body LEDs are suitable for larger display light sources and displays.
Manager Liang said that as a global pioneer in LED lighting technology, Osram launched three primary color LED display applications in 1999; in 2008, it launched the smallest package R.G, B three in one LED at the time.
However, in the future, after the overall layout of the 1010 and 0808 LED packages, the focus will be shifted from the miniaturization of the package to the operation of converting the LEDs to the black body wafer substrate, so that the large display screen will show high contrast.
Finally, the lamp beads for indoor LED large screens in the future will use new LEDs to form 16×3 in one and 64×3 in one packages, making products with smaller ppi, better optical design and more reliable products.