Aspheric surface technology in the application of the CCTV camera
Aspheric technology is currently one of the more popular topic.
Actually aspheric technology is widely applied as early as in the photographic object, is introduced into the CCTV camera is about 10 years ago.
So what is a sphere?
Actually for the aspherical lenses, if with the naked eye observation, often look is still a roughly spherical shape, not flat.
For the face form of aspheric lens is on the basis of the spherical surface shape do slight adjustment, from the point of view of mathematics, the shape function of the spherical surface is a quadratic function, but the aspherical surface shape function is the function of four or more times, are usually designed to 10 times, so the aspherical surface shape is more complicated.
More figuratively speaking, aspherical surface shape is based on the spherical surface shape, on the basis of the sphere of human control, subtle surface shape ups and downs, good design in advance to make the lens surface shape presents the complexity of the aspheric surface.
Aspheric in each aperture with different focal power.
People tend to think that a beam of light through a convex lens (
The most common spherical lens)
, which can be gathered at the point.
For example, a lot of people who use a magnifying glass to gather the sun burn play experience.
But from optical perspective, the spherical lens does not actually gathered in the light point, it has gathered, is actually a flare.
Due to the naked eye sight is limited, so it looks as if a little.
This is due to the deficiency of spherical lens have a, it has a known as the 'spherical aberration' defects, and through single pieces of spherical lens itself cannot overcome this aberration, it is this aberration, so the light spot phenomenon.
This aberration can dramatically affect the imaging quality.
But the aspherical lenses can accurately to a point on the light, a spherical aberration, significantly improve the quality of imaging.
Aspherical lenses used to the camera, what is the specific advantages?
Aspherical lenses can make the lens of the application of optical structure relatively simplified, thus on the optical design and mechanical structure are more likely to gain greater diameter light, make the whole picture more bright.
Aspherical lenses can greatly improve the image quality, make the picture clearer, especially the edge image clarity.
When aspherical application in the main light high surface, it can also correct astigmatism and distortion of off-axis aberration, making off-axis imaging but also greatly increased, this tremendous implications in practical use, it makes the picture can clearly show in every detail, but due to the vague concepts cannot avoid have images as evidence of helpless situation.
One aspherical lens can replace a set of spherical lens, so using aspheric lens can realize miniaturization of the lens volume.
Aspherical lenses in design with the aid of sophisticated optical software is not difficult, but it needs high technology and its production and processing technology.
So in CCTV lens can be their own independent complete the development and production of aspheric lens makers are numbered, rather than the development and production of spherical lens technology became the core technology of an enterprise.