Some modern televisions incorporate features designed to enhance the display for gaming. These include DLG (Dual Line Gate) and HSR (Hardware Super Resolution) technologies, which increase smoothness by offering higher refresh rates than those natively supported by the screen. Both methods rely on special image processing that modifies the way lines of pixels are displayed on screen.
DLG (Dual Line Gate)
DLG technology doubles the panel’s native refresh rate. To achieve this, DLG uses an alternating scan method in which two lines of pixels are displayed simultaneously instead of just one. In concrete terms, instead of reproducing all the lines of the source image, the TV displays certain lines twice in succession. For example, the first line of the image is duplicated, the third also, and so on, while even-numbered lines are omitted. This way, refresh rates ranging from 120 to 240Hz can be achieved, depending on the model.
This process changes the vertical definition of the image from a 3840 × 2160 pixel signal to an equivalent 3840 × 1080 pixel representation when DLG mode is active. This method offers improved image smoothness in games, by doubling the display frequency, which improves responsiveness and legibility of fast movements. In practice, and for reasons of compatibility with games consoles, the definition then changes to 1920 × 1080 pixels. This option is available in TV menus, notably those of TCL and Philips.
HSR (Hardware Super Resolution)
HSR is based on a similar principle to DLG, modifying the way pixel lines are rendered on screen to enable higher-frequency display. However, instead of simply duplicating the visible lines, this technology calculates intermediate lines from the available data. For example, if the television displays the first and third lines of a source image, it generates a second line by interpolation between these two lines. In this way, the processing aims to reproduce a more complete image despite an effective reduction in vertical resolution.
In direct comparison with DLG, HSR offers finer visual reproduction. The calculated lines retain more information than those simply copied, resulting in a sharper image, despite the reduction in definition. Some TVs, such as those from Hisense, use this process to offer displays at up to 240Hz in 1080p, for smoother playback of fast-moving games.
🗒️ Expert's note
HSR (High-Speed Refresh) technology improves display smoothness by simulating a higher refresh rate, ideal for sharper images in fast-moving scenes. However, this interpolation can introduce a slight latency, imperceptible to most gamers. For competitive games, where every millisecond counts, the native refresh rate should be used for optimum responsiveness. In this case, a dedicated gaming monitor may be more appropriate.
DLG and HSR technologies represent two different approaches to improving display fluidity in video games, by increasing the number of frames per second displayed on screen. The former relies on a system of line duplication to reach 120Hz or more, while the latter introduces an interpolation calculation that enables more precise rendering, despite a similar reduction in vertical definition. These devices do not replace a native high-frequency display, but provide a technical solution for taking advantage of the capabilities of compatible TVs without the need for additional external hardware.
