Machine Vision Telecentric Lens

Telecentricity Definition

A telecentric imagingis a kind of lens that the chief rays are parallel to the optical axis. There are three kinds of telecentric lens, that is the object-space telecentric laserlens, image-space telecentric lens, and the bi-telecentric lens. Telecentric lens is always the core business of Canrill Lens. After continuous research and development for 11 years, Canrill has successfully developed 1700+ kinds of lenses, and the number is still increasing, to meet the diverse and growing applications at the best telecentric lens price.

Difference Between Object Space Telecentric Lens And Bi Telecentric Lens

Telecentric lenses have two types of telecentricity: object space and image space telecentricity (referring to the entrance and exit pupil positions, respectively). Therefore, telecentric lenses are divided into: object space telecentric lens, image space telecentric lens, and bi telecentric lens.

Object Space Telecentric Lens

In general, a machine vision telecentric lensrefers to an object space telecentric lens. If the entrance pupil of the lens is located at an infinite position in the image side (all objects behind the objective lens), it can be called an object space telecentric lens. The chief ray originated from optical axis is parallel with optical axis in object side ( or to say have very small angle θ which is called telecentricity in telecentric lens specs), while in image side is not parallel.

object space telecentric opticswith entrance pupil projected to infinity on the image side

In the optical design, object space telecentricity is achieved by placing the system's iris diaphragm at the intersection of the front-end groups. Since the entrance pupil is at infinity, the field of view is constant and has no field angle. Since the chief ray (which defines the system's field of view) passes through the optical axis at the aperture stop, when the pupil is at infinity, the ray is parallel to the optical axis and the field of view is zero. By contrast, any entrance pupil within a finite distance of the lens results in a non-parallel fiber.

An object space telecentric lens in which the chief ray is completely parallel to the optical axis in the object space. Note that the field of view does not change no matter where the object plane is, because the chief ray that defines the field of view is perfectly parallel to the optical axis.

The entrance pupil is located where the object-side principal ray passes through the optical axis.

Although object space telecentric lenses can provide much higher measurement accuracy than conventional lenses, bi telecentric lenses can also achieve higher accuracy if the lens is object and image space telecentric. The principle of image space and object space telecentricity also applies in bi telecentric lenses. In a bi-telecentric lens, the entrance and exit pupils project to their respective infinity. The chief ray originated from optical axis is parallel with optical axis in both object side and image side ( or to say have very small angle θ which is called telecentricity in telecentric lens specs).

Bi-telecentric lens with the entrance and exit pupils projected to infinity in the image and object spaces respectively

Bi-telecentric lenses are the most accurate type of telecentric lenses because their field of view is completely unaffected by changes caused by changes in object position or sensor position, nor does it operate any cos4θ attenuation. The diagram below shows the comparison of three different lenses: fixed focal length lens, object space telecentric lens, and double-telecentric lens. The X-axis represents the change in working distance (mm) from the nominal value, and the Y-axis represents the dimensional error percentage from the actual value.

As you can see, the bi -telecentric lens is the most accurate lens in the group, with a working distance offset of 4mm and an error of less than 0.2% during this period. Bi-telecentric lenses should be used in applications that require the highest accuracy and precision.

Non Telecentric Lens

The chief ray originated from optical axis has a angle θ with optical axis. For objects at different WD from the lens, the lens will have either smaller or larger mag.

If you want to know more about how to make a telecentric lens, please visit our website.

As a lens manufacturer, we will offer kinds of image space telecentric lensfor sale, anything you need, please contact us.

Другие товары поставщика

	Microscopy Lens	Suitable for ITO, particle detection, wafer inspection Infinity optical design can match infinity objective lens with a different mag High-contra...
	Telecentric Illuminator	Better clarity and WBC, higher telecentricity Especially suitable for round workpiece measurement、 Specification Of Telecentric Illuminator M...
	8k Line Scan (57.4mm) Telecentric Lens	Suitable for large format Area Scan Camera Line Scan Camera 16Kx3.5μm, 8Kx7μm, 8Kx5μm Adjustable iris makes it possible to balance DOF ...
	Low Mag 2/3' Sensor Telecentric Lens	Megapixels high-resolution object space telecentric lens Wide magnification ranges from 0.0282X to 0.5X Bi-telecentric design and object tele...
	1.1' (18mm) Sensor Telecentric Lens	Optimized bi-telecentric lens for 1.1' 3.45um cameras High mag and low mag of this series of machine vision telecentric lens are both available ...

Все товары поставщика

Похожие товары

	8.0MP 10-40mm Zoom Lens 1/1.8" F1.4 Format Machine Vision Lenses	Продавец: Shenzhen Wikshu Technology Co.	Описание Ручной зум 8.0mp C Mount 10-40mm объектив Ручная апертура объектив машинного зрения 1/1....
	Microscope Objective Lens	Продавец: Shenzhen Canrill Technologies Co., Ltd	Microscope Objective Lens Suitable for ITO, particle detection, wafer inspection Infinity opt...
	DMD Lithography Lens	Продавец: Shenzhen Canrill Technologies Co., Ltd	DMD Lithography Lens We have been in close cooperation with LDI (Laser Direct Imaging) manufactu...
	8k Line Scan (57.4mm) Telecentric Lens	Продавец: Shenzhen Canrill Technologies Co., Ltd	8k Line Scan Lens Suitable for large format Area Scan Camera Line Scan Camera 16Kx3.5μm, 8Kx7...
	16k Line Scan (82mm) Telecentric Lens	Продавец: Shenzhen Canrill Technologies Co., Ltd	16k Line Scan (82mm) Telecentric Lens Specially designed for large image circle up to 82mm in le...