In this blog post, we’ll explain how 3D TVs work and compare the different implementation methods used by Samsung Electronics and LG Electronics.
Basic Principles of 3D Perception
The fundamental principle behind human perception of three-dimensional objects lies in the fact that each eye receives different visual information. When the brain combines the differences between the images received by the left and right eyes to extract depth information, we are able to perceive three-dimensional space. 3D TVs artificially replicate this physiological principle, providing viewers with a sense of depth by delivering different images to the left and right eyes, respectively.
Samsung Electronics’ Shutter Glasses Method
Samsung Electronics has adopted the “shutter glasses method,” which incorporates electronic shutters into the viewer’s glasses. In this method, the TV alternates between displaying images for the left eye and the right eye at a very high speed, and the shutters in the glasses are synchronized with the TV, repeatedly opening one lens while closing the other. Synchronization between the TV and the glasses is achieved using wireless technology such as Bluetooth, and by flickering the screen at a refresh rate so high that it is imperceptible to the human eye, it ensures that each eye receives a separate image.
The advantage of the shutter glasses method is that it uses the same screen as conventional 2D TV panels—simply alternating between left and right images—which requires minimal changes to the production process and is conducive to mass production. Additionally, since it can utilize existing high-definition technology designed for 2D, there is minimal degradation in basic picture quality. On the other hand, the disadvantages include the fact that the glasses are relatively heavy and expensive because they contain electronic circuits and a power supply, and some viewers may experience dizziness or discomfort due to afterimages caused by the alternating flickering. These drawbacks can significantly affect user comfort and immersion, making technical improvements necessary.
LG Electronics’ Polarization Method
LG Electronics uses the “polarization method,” which involves applying a polarizing film to the screen. This method creates microscopic irregularities (curvatures) on the screen’s surface, causing light with different polarization states to emerge from the left and right slopes. The glasses incorporate polarizing filters with different orientations in each lens, allowing only the respective left- and right-eye images to pass through. For example, light emitted from the left-hand side of the screen is vertically polarized, while light from the right-hand side is horizontally polarized; the left lens of the glasses then allows only vertically polarized light to pass through, and the right lens allows only horizontally polarized light to pass through.
The strength of the polarization method is that the glasses serve only as simple polarizing filters, so they do not require electronic components or a power source, making them lightweight and inexpensive. They are comfortable to wear and offer high design flexibility, making it easy to create them in a form similar to regular glasses. Additionally, since there is no shutter opening and closing, there is less afterimage caused by screen flickering, resulting in less dizziness. On the other hand, a drawback is that the screen must be textured and images must be displayed on different slopes, which requires a different panel design and may result in lower image quality.
Comparison of the Two Methods and Market Outlook
Given that Samsung and LG hold a significant share of the global TV market, the differences in the 3D implementation methods adopted by these companies have a major impact on the competitive landscape.
Technically, the shutter-glass method allows for the direct use of existing 2D panels, making it advantageous for maintaining high image quality in the short term, while the polarized method offers strengths in terms of lightweight glasses, low cost, and wearing comfort. Furthermore, while the shutter method must address issues such as afterimages, dizziness, and the weight and price of glasses, the polarized method faces the challenge of improving image quality degradation on the panel side.
In my personal view, I believe polarization-based solutions are likely to have an advantage when the era of glasses-free (autostereoscopic) 3D arrives. Since glasses-free technology cannot rely on synchronization via the opening and closing of shutters, as in the shutter method, technologies such as polarization or lenticular lenses—which separate light by direction directly on the screen—will inevitably become key. However, autostereoscopic 3D still faces technical challenges, such as viewing angle restrictions. As 3D content increases and the technology matures, it will be interesting to see what criteria consumers use to choose products and how Samsung and LG respond to these trends.
