What is the mainstream laser TV display technology today?

    Laser TV and laser projection are words that are completely unfamiliar to consumers. Although Mitsubishi, Sony and other manufacturers have launched such products before, due to the high cost and the gradual maturity of the LCD market, they have finally become just a mark in the history of home appliances. However, with Hisense's high-profile launch of its 100-inch laser TV not long ago, this product, which has always been high on the list, has once again entered the eyes of consumers.

    At present, the so-called laser TV is actually more similar to projection in form, but what is different is that it can project hundreds of inches of images at a distance of less than 1 meter. With the release of Hisense laser TV, this type of product is technically divided into two camps, one is the ALPD technology represented by Lightpeak, and the other is the laser cinema system that Hisense claims to have independently developed. So, what are the differences between these two technologies, and can laser TV become the next king in the field of television?

Laser TV is not like this

Early Mitsubishi Laser TV

    In fact, laser TVs have been around for 10 years. According to data, Sony once displayed a 500-square-meter laser theater in 2005, and Mitsubishi and Sony also launched laser TVs of different sizes in 2006 and 2007. At that time, these giants predicted that laser TVs would enter a period of rapid growth in 2012 and would replace existing LCD TVs in 2015.

    However, after nearly a decade of development, the seemingly bright road of laser TV has not only failed to advance as the giants imagined, but a group of manufacturers such as Mitsubishi and Sony have turned from pioneers in the field of laser TV into martyrs, and have left in disgrace.

    In terms of form, the original laser TV was not a separate host and screen like today, but a real TV. Technically, it is a display system composed of a laser emitter, a modulator, a deflector and a screen. When the system receives the video signal, it is separated into three-color (red, blue, and green) image signals, and the semiconductor laser diodes that control the three colors emit light of corresponding intensity after processing. After modulated output and signal synchronization control, the light beam of the optical deflector is scanned onto the screen to form an image.

Principle of early laser TV

    However, the biggest problem with this technology is that it is too expensive. The three colors of red, green, and blue are all produced by lasers, but the energy of green lasers is not enough and the cost is very high. In addition, the laser will generate high temperatures and burn the screen during operation, and a large heat dissipation system is required. Obviously, this technology is difficult to enter ordinary households.

    However, in recent years, a new form of laser TV has emerged, which is the host + screen format that everyone sees now. It technically uses a monochromatic blue laser to stimulate phosphor conversion and present it in the form of ultra-short-focus lens projection. This solution, called laser phosphor, not only effectively controls costs, but also solves the heat dissipation problem to a certain extent. Therefore, although the current price of laser TVs will range from 70,000 to more than 100,000, the actual price has dropped a lot compared to before, and because it is presented in a similar projection manner, it has also made breakthrough progress in the size of the screen.

Currently, mainstream laser TVs all use the same technical solution

    Just now we mentioned that the current laser TV products are roughly divided into two camps in terms of technology. One is the ALPD technology represented by Guangfeng, and the other is the laser cinema system that Hisense claims to have independently developed. In terms of price, the Changhong laser TV in the Guangfeng camp is priced at around 60,000 yuan, the Xuanmu laser TV equipped with an audio system is priced at 120,000 yuan, and the Hisense laser TV is priced at 69,999 yuan. Obviously, even in different technical camps, the prices of these products are almost at the same level. The reason for this situation is not unrelated to the similarity of their actual technical architecture.

Mainstream laser TV display solutions

Hybrid laser source technology

    It is understood that both ALPD technology and Hisense's self-developed technology have actually abandoned the previous use of red, green and blue lasers, and turned to using relatively low-cost semiconductor blue lasers to emit blue lasers to excite high-speed rotating phosphor wheels, thereby forming different color light sources. The only difference is that they differ in their internal details.

Lightpeak ALPD phosphor laser display technology

    For example, Hisense said that although its laser TV also uses the blue laser to excite phosphor, the red and green light are both excited by phosphor, while some red parts are excited by LED, so it is called a hybrid light source. Similarly, Guangfeng said that their technology can not only convert green and red light from blue laser, but also innovatively excite yellow light here to achieve a more realistic color effect.

Working principle of Hisense laser fluorescent light source

    In addition, it is understood that Hisense Laser TV's internal optical and mechanical modules, light source modules, and ultra-short-focus lenses are all independently developed. According to industry insiders, in terms of optical and mechanical modules, Guangfeng and Changhong use LG's optical and mechanical modules, while some other domestic manufacturers use products from other Japanese companies.

    In addition, even though LG's optical module also uses an ultra-short focus lens, the principle is different from the technology of the ultra-short focus lens on the reflector in Hisense's laser TV optical module. Hisense uses a flat mirror, while other products mostly use curved reflectors, which may result in some deviations in distortion.

    Of course, as mentioned before, even if the details of the technology used by each company are different, the overall design concept and usage plan are basically the same, so there is basically no difference between good and bad. And it is precisely because of the emergence of this plan that the current new laser TVs with relatively low prices and large screen sizes have appeared, and they are fully prepared for the next step of entering ordinary households.

The image effect is still different from that of TV

    From the current form of laser TV, the appearance is more similar to that of projection, which makes consumers compare it with projection. In terms of ease of use, laser TV is indeed superior to current short-throw projection products in many aspects. For example, due to its own principle, laser TV can project a picture of more than 100 inches at a distance of less than one meter. This is closer to the use environment of ordinary families than any projector in terms of practicality.

    In addition, laser TV users who buy projector products usually project the image directly onto a white wall or screen, and the quality of the white wall or screen, including light reflectivity, white balance, etc., will affect the final projection effect. Laser TV is different, it is usually equipped with a professional screen. The screen is made by combining a variety of material technologies, coating technologies, and Guangyu micro-lens principles, so that the projected image can be reflected as originally as possible to the human eye. Compared with ordinary projection screens, it can more effectively resist the interference of ambient light, making the picture effect more outstanding.

    However, since laser TV belongs to the category of television products, even though it has the characteristics of large screen, strong resistance to ambient light, and long service life, these are only advantages compared with projector products. There is still a certain gap in its actual imaging quality compared with ordinary LCD TVs.

    Taking the 100-inch Lightpeak Screen Projector we have tested as an example, no matter how good the projected display effect is, it cannot reach the effect of an LCD TV with its own backlight, especially because the ambient light has a significant impact on it. In addition, in terms of viewing angle, due to the special reflective principle of the panel, the viewing angle of laser TV cannot achieve an ultra-wide angle like LCD TV. After exceeding 120 degrees, the brightness will drop significantly.

    Although the performance of laser TVs in NTSC color gamut is above average compared to that of LCD TVs, there is still a big gap in actual experience. Data shows that the maximum brightness of Xuanmu laser TV is 200nit and Hisense laser TV is 250nit. The mainstream LCD TVs on the market generally have a brightness of about 500nit due to their own backlight luminescence principle. In comparison, the viewing experience will still be more beautiful, transparent and eye-catching on LCD TVs. Coupled with the influence of ambient light, the slight advantage of laser TV in color gamut is even more ruthlessly killed.

Summarize

    After talking about some technical aspects, let's take a look at the price. The mainstream laser TVs are priced between 60,000 and 100,000 yuan. Whether it is Guangfeng's Xuanmu or Hisense's Laser Cinema, they are compared with LCD TVs of the same size in their promotional strategies. Obviously, if we simply compare them in this way, the price of laser TVs is much lower than that of LCD TVs of the same size even if they are hundreds of thousands, but such a comparison is obviously unscientific. After all, for a TV product, the size of the screen is only one aspect of the visual experience, and the picture quality is the decisive factor that determines the final viewing experience.