In 1948, warmisham hired gordon cook, who was responsible for many cooke zoom lenses. A telecentric lens is a compound lens that has its entrance or exit pupil at infinity. The distance between the object and the edge of the lens mount at which the image is sharpest. With bitelecentric lenses, the magnification in both image and object space is independent of distance within the depth of field or the position in the field of view. In fact even the coatings are designed to reduce the light. The near telecentric construction of lenses optimised for the four thirds standard ensures light hits the sensor at almost perpendicular angles. Pdf telecentric largefield lenses using fresnel optics. Aug 20, 2012 order design of a doublesided telecentric zoom lens. Strictly speaking, a telecentric lens is a special lens with at least three very amazing properties. Telecentric lens sod10x 20xvi high magnifi cation machine micro lens sodx high magnifi cation machine micro lens super optical devicesod10x 10x optical magnifi cation capable of 15x and 20x with rear converter lenses high na of 0.
Figure 2 shows two different objects at different working distances, both imaged by a fixed focal length nontelecentric lens center and a telecentric lens right. The scale ratio is determined by the lens design ata fixed flangetosensor distance cmount as standard. Ideal for a wide range of applications, including precise dimensional measurement of objects or pattern recognition. Dec 19, 2006 a new cdrom accompanies this edition, offering extensive lens prescription data and executable zemax files corresponding to figures in the text. By design, the entrance pupil is infinitely far behind the objectspace lens so that looking in the front causes the aperture to appear very far away. At least one lens element will be larger than the field size to be scanned.
Telecentric lens this telecentric zoom lens series is used for high performance inspection and object recognition when a wide range of fov and long wd are required. Telecentric lenses are designed to have a constant magnification regardless of the objects distance or location in the field of view. L10 telecentric lens sod10x 20xvi high magnifi cation machine micro lens sodx high magnifi cation machine micro lens super optical devicesod10x 10x optical magnifi cation capable of 15x and 20x with rear converter lenses high na of 0. In lens design with large computers, proceedings of the conference, institute of optics, government superintendent, rochester, new york. Solutions include complete optomechanical and optoelectronic assembly and subassembly systems. In the example above, the now front element is quite small i remembered my olympus zuiko 501. Continuing the bestselling tradition of the authors previous books, lens design, fourth edition is still the most complete. In a telecentric lens system, all chief rays are parallel to the optical axis, maintaining the same image size through focus top left. But the not all the lens designs are simple lenses, we will look at newer and important lens design forms as well. This means that the chief rays oblique rays that pass through the center of the aperture stop are parallel to the optical axis in front of or behind the system, respectively. Vision telecentric lens wd145 series megapixel object side telecentric lens suitable for,12,11. In contrast, a nontelecentric system with its nonparallel chief rays causes image size to vary with focus top right. Changes in focus from the ideal point do not affect the magnification. The magnification does not depend on the distance from the lens to the object, nor on the distance from the lens to the film.
The mlz and mlz hr series offer integrated coaxial illumination, adapter lenses, and motorized zoom function options. Our products range from high magnification motorized zoom imaging systems to fisheye projection lenses used in a wide variety of industries including life sciences, industrial. In order to achieve a telecentric lens design, all. Thorlabs has collaborated with navitar to design and manufacture a line of telecentric lenses for machine vision applications.
Micro four thirds what about the importance of the telecentric lens design. The telecentric lens provides distortionfree and constant magnification within depth of field image, so it has become an indispensable key module in the amount of visual measuring system. Each lens also features a standard front filter thread for use with color filters, polarizers, protective windows, and illumination adapters for led or. For more than 40 years, computar has been the world leader in optics across industries including intelligent traffic systems, machine vision, defense, security and life sciences. This means the exit pupil after the telecentric barlow lies at infinity. Dtcm16k series linescan bi telecentric lenses are designed and optimized for highprecision application including metrology, inspectation etc. Techspec silvertl telecentric lenses are designed for metrology and gauging applications and offer inline illumination options for maximum versatility. This is accomplished by ensuring that the system stop is located at the front focal point of the lens system. When your application requires perfect vision, you know where to turn. In contrast, a nontelecentric system with its nonparallel chief rays causes. These lenses feature a 23 sensor format and a variety of different working distance and magnification options.
The primary advantage of a telecentric lens is that its magnification does not change in respect to depth. Each lens also features a standard front filter thread for use with color filters, polarizers, protective windows, and illumination adapters for led or fiberoptic ring lights. Accessories our tc family is complemented by a full set of accessories. Our bi telecentric lens has wide range of selection and is capable of fitting to many cameras available in the market, and shows the best fit to wide range of precise measurement application. Jenmetar telecentric lenses are designed for fixed scaleratios. Telecentric scanning lenses introduction telecentric scanning lenses are a special configuration in which the arrangement of optics are designed to focus down the beam such that it is always perpendicular to the flat field figure 10. But all of these software packages share one critical flaw. The other lens types behave pretty much like the human eye things that come nearer appear to grow. Like other types of telecentric lenses, objectspace lenses are larger, heavier, and more expensive than other optics with the same focal length and fnumber.
The thirdorder aberration analysis is also performed, and spot diagrams are calculated for two fnumber values. The design and fabrication of telecentric lens with large. Aug 07, 2008 when olympus launched the standard four third format they argued for the distance from the lens to the sensor, and today you can still find this information on their internet home page copypasted. Field guide to lens design 2012 bentley publications. The same principles of image and object space telecentricity hold true. Oct 01, 2004 strictly speaking, a telecentric lens is a special lens with at least three very amazing properties.
Figure 2 shows two different objects at different working distances, both imaged by a fixed focal length non telecentric lens center and a telecentric lens right. The telecentric lens consists of a zoom lens with a fixed distance between focal points and a lens with a fixed focal length. While advancements in the field over the past two centuries have done much to transform it from the former category to the latter, much of the lens design process remains encapsulated in the experience and knowledge of industry veterans. The so called telecentric barlow is image space telecentric. Optical lens design is the process of designing a lens to meet a set of. Dtcm16k series linescan bitelecentric lenses are designed and optimized for highprecision application including metrology, inspectation etc. This is the design position of the entrance pupil for most eyepieces. Filled with sage advice and completely illustrated, lens design, fourth edition supplies handson guidance for the initial design and final optimization for a plethora of commercial, consumer, and. The process of designing lenses is both an art and a science. Cmount, inspect application suitable mega telecentric lens wwh series. The true telecentric lens has a zero field of view in practice this means that its field of view is limited to the diameter of the lens front element. There is no shortage of lens optimization software on the market to deal with todays complex optical systems for all sorts of custom and standardized applications. Zoom telecentric lenses the 12x telecentric zoom system allows users to reach a true telecentric condition to within 0.
This tutorial introduced the concept and set up for the objectspace telecenric system and imagespace telecentric system and advantages of telecentric lens that can impact the system performance. Telecentric bi telecentric lens for machine vision. Navitar designs, develops and manufactures innovative optical solutions for clients and enterprises across the globe. Micro four thirds what about the importance of the. Our unique optical design capabilities result in the tightest object and image side. Precision lenses do an excellent job conveying contrast and color from object to image, but they can do a poor job of transferring accurate dimensions, especially if they have small focal lengths. If a non telecentric lens is image space telecentric, it will typically be denoted.
To affect the lens focus location and imaging performance in highly corrected pact design of an illumination unit with double telecentric optics to achieve. Video telecentric lenses navitar optical solutions. In practice, this means that for reasons of manufacture and cost that only small field sizes are possible, in turn implying short focal lengths. This change in magnification with respect to distance is partially what allows for depth. Double sided telecentric design techspec platinumtl telecentric lenses are designed for semiconductor and electronics inspection, measurement, and gauging applications. Standard telecentric lens high resolution telecentric lens bitelecentric lens fmount telecentric lens mc telecentric lens distance 9. While object space telecentricity provides a substantial boost to gauging accuracy over conventional lenses, even greater accuracy can be achieved if a lens is both object and image space telecentric doubly telecentric. This attribute is ideal for many machine vision measurement applications, as measurements of an objects dimension will be independent of where it is located. Telecentric lenses however keep the size of objects. Our bitelecentric lens has wide range of selection and is capable of fitting to many cameras available in the market, and shows the best fit to wide range of precise measurement application. A method is presented for the calculation of paraxial design parameters of a doublesided telecentric zoom lens with easy variation of the magnification range. The basic lens design forms are in here, and we can take a deep look into the development of lens design. Both tzsystems are not intended to work as a barlow lens. Although i have taken a great deal of effort to assure accuracy, the user of any of.
The article presents a design and development of telecentric lens module for the wide range of vision inspection system fieldofview 100 mm. Also, some recent advanced product of telecentric lens or systems. Tutorial of telecentric lens university of arizona. Traditional lenses work in the same way as the human eye. Spot diagrams were calculated for two f number va lues f 5.