On the lighting environment of visual comfort

Abstract: the intense rhythm of life has aroused people's attention to the lighting environment. The anti glare brightness and suitable ratio is the basic factor of visual comfort, should be the basic consideration to the office and other types of environmental lighting, and has shot light, enough power, basic height and reasonable position and so on is reading lamps provide a comfortable lighting environment.

Key words: glare; luminance ratio; reading and writing lighting; office lighting; classroom lighting

More and more attention to the protection of the vision, the market "eye protection desk lamp" came into being, people are very concerned about the "eye lamp" in the end to protect the eyes? How can ability protect vision? Involved in the family, the office of reading and writing operations, with the popularity of computers, computer screen reading and writing before the operation, compared with the traditional reading and writing operations, the display may bring new visual problems. The quality of reading and writing homework has become the focus of attention of the public.

Elements of visual comfort

1 avoid glare

To establish a comfortable lighting environment to avoid all kinds of glare. There are two reasons for the glare: brightness is too high or brightness ratio is too high.

- the brightness is too high is the most common sunshine brings too much light, the observer is squinting, blink or far too much light on the simple light response, and the most appropriate solution to this problem include reduced retinal brightness, such as wearing a top hat edge, the bright part of the field of view for occlusion handling; such as wearing sunglasses, in order to reduce the brightness of the entire field of view.

- brightness ratio is too large in the visual environment of the brightness range is too large, it will produce glare, reduce visual function.

2 brightness limit

For the design of a direct lighting fixture, the use of a special brightness value is important. Figure 1 shows the geometric relationship of the VDT lighting to highlight the area.

The luminance of a specific angle luminaire is a calculated value. Because some screens provide wide angle reflection of the space, in the open layout of the environment, many lamps may be in the glare area, when the vertical, horizontal or 45 degrees to observe the lamp, should limit the average brightness. And is usually provided with an increment of 5 degrees or 10 degrees. Determination of the light intensity at a given angle and the projected surface area of the luminaire in the photometric laboratory. The luminance values of the lamps of different sizes are different, even if the actual light intensity at a specific angle is the same. Table 1 gives the recommended values and maximum values for the average luminance at a specific angle. VDT (video display terminal) office operation should be used to optimize the recommended value. It provides the possibility for the lowest reflection curtain or reflected glare. The maximum value provides a greater possibility for the VDT on the screen or reflection reflection glare, which is suitable for VDT operation, and only occasionally is not the main visual task office.