Comparison of display technology between laser television, laser projection and large flat panel

Laser TVs are not equivalent to laser projection. There are also many differences between LCD TVs and OLEDs currently available on the market. The author will introduce them in detail and hope to give you answers.

Laser Television Technology Principle

Since the discovery of the laser, after many years of continuous development, it has been applied in many fields such as military, medical, and civil use. In laser display technology, technology is highly regarded as one of the important development directions in the laser field.

Laser TV is not a new concept. In the 1990s, there was a technology prototype. In 2003, laser television prototypes were launched. From 2006 to 2007, consumer electronics giants such as Mitsubishi and Sony also launched laser television prototypes in succession. In the early days of the development of laser television, foreign consumer electronics giants played the role of laser technology promoters.

Although in the wave of display technology, domestic manufacturers are in a state of follow-up, but in the field of laser television, domestic manufacturers have finally seized the opportunity. In 2014 alone, domestic manufacturers such as Hisense, Optoma, Changhong, Hualu, Konka, Meire, and Yidian launched laser televisions, which means that the “explosion period” of laser televisions seems to have come! So how about the display principle of laser television? Next, the author will give you a good introduction.

In fact, the working principle of laser television is also easy to understand, mainly composed of laser, optical deflector and screen. The laser television is mainly composed of a laser, an optical deflector, and a screen. A semiconductor-pumped solid-state laser is used to generate R (red), G (green), B (blue) continuous, three-wavelength laser light sources, and R is controlled by a television signal. , G, B laser scan images.

Laser projection technology principle

When it comes to laser television, then you have to mention laser projection. Laser projection uses red, green, and blue (trichromatic) monochromatic lasers with higher power (watt levels) as the light source, mixed into full color, and uses a variety of methods to achieve line and field scans when the scanning speed is higher than the imaged The critical flicker frequency can satisfy the human eye's "vision residue" requirement and can be clearly observed by the human eye.

The earliest laser projection technology used gas lasers as light sources, such as He-Ne, argon ions, xenon, and copper vapor lasers, radiating red, blue, and green lasers, respectively, to achieve full-color laser projection, but the gas laser's electro-optic efficiency was low and Relatively poor work reliability.

Laser, diode-pumped, all-solid-state lasers and frequency doublers can also obtain red, green, and blue radiation, with continuous output powers of several watts, tens of watts, and even hundreds of watts. These all-solid-state lasers have high electro-optical efficiency and stability, and they are compact. A few watts of power can be used for laser projection.

Now many people, laser television, laser projection silly unclear, after all, technically, laser television and laser home projector has many of the same place, but in essence, the former belongs to home audio-visual entertainment center, while the latter is It is only part of the entire video system.

In addition to the functions of projection display, laser television also incorporates many functions into one, allowing users to build a small world of audio and video entertainment without having to collaborate with other devices, while laser home projectors need to be matched with others. Projection screens, AV amplifiers, home theater speaker systems, and a variety of signal source devices can truly constitute a complete large-screen multi-channel audio and video entertainment overall solution.

Large LCD (LED LCD OLED)

LED technology principle

The LED display technology is a display screen for displaying various information such as characters, graphics, images, video signals, etc. by controlling the display mode of the semiconductor light emitting diodes. LED displays have gone through the development of monochrome, bi-color graphic displays, picture displays, and today's full-color video displays. The level of ultra-high-brightness full-color video display that has been achieved so far has been applied in various areas such as transportation, securities, telecommunications, advertising, and publicity.

The main controller acquires the brightness data of each color of each pixel of a screen from the computer display card, and then distributes it to several scanning boards. Each scanning board is responsible for controlling several rows (columns) on the LED display screen, and each row (column) LED display signals are serially transmitted through the display control units of the bank in a serial manner. Each display control unit directly faces the LED display screen body.

The work done by the main controller is the format of the data and control signals needed to convert the signal from the computer display to the LED display screen. The function of the display control unit is similar to that of the image display screen and is generally constituted by a shift register latch having a gray scale control function. Only video LED displays are often larger, so integrated circuits with larger scales should be used. The role played by the scanner is the same as the previous one. On the one hand, it accepts the main controller's video signal. On the other hand, it transmits the data belonging to the current level to each display control unit, and at the same time, the data that does not belong to this level is A cascaded scan pulls the transmission. Video signals and LED display data, in the space, time, sequence, and other differences, all need to have a scanning board to coordinate.

LCD technology principle

For many people, LCD is not a strange name, and it can even reach a familiar stage. After all, most of the TVs that occupy our living room are also this. Because of price and technological maturity, it will continue to occupy us. Living room for a long time.

The principle of LCD display is to place the liquid crystal between two conductive glasses, driven by the electric field between the two electrodes, causing the liquid crystal molecules to distort the electric field effect of the column to control the transmission or shielding function of the light source. When light and dark are generated, the image is displayed. If a color filter is added, a color image can be displayed.

Since alignment films are arranged on the two glass substrates, the liquid crystals are aligned along the grooves. Since the grooves of the alignment film on the glass substrate are deviated by 90 degrees, the liquid crystal molecules become twisted. When the glass substrate is not applied with an electric field, the light passes through the polarizing plate. With the liquid crystal to make a twist of 90 degrees, through the lower polarizer, the liquid crystal panel displays white; when the glass substrate is added with an electric field, the liquid crystal molecules produce a collocation change, the light maintains the original direction through the gaps of the liquid crystal molecules, and is blocked by the lower polarizer, and the light is absorbed and cannot be penetrated. Out, LCD panel shows black. The liquid crystal display is based on this voltage, so that the panel achieves the display effect.