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Does the term "projection lens" have a specific optical implication? Could a "projection lens" be a "scan lens"? I have done some preliminary research and cannot seem to find any specific optical formulas that would state conditions for a "projection lens" whereas a scan lens seems to have a pretty specific definition.

As I understand it, regarding a scan lens, this is a "lens having f-theta distortion correction and telecentricity;" where "conventional lens distortion correction results in a scan position of f.tan theta for a scan angle of q. By designing into the lens the correct amount of barrel distortion, the scan position can be made to be f.theta;" and "a telecentric scan lens is one in which the chief ray of the focused beam is parallel to the optical axis at all scan angles." Given these assumptions, would you have a "projection lens?"

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  • $\begingroup$ In the context of lithography (for semiconductor manufacturing) they can have slightly different meanings - a projection system images the entire chip at once (step-and-repeat), while a scan system, well, scans over the chip area (step-scan-repeat). This allows for a higher precision lens to be produced more easily since the field area is smaller. $\endgroup$ – Jon Custer Nov 4 '16 at 16:18
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I don't know what a "scan lens" is, but a projecting lens is the lens on the front of a projection lantern. It is a converging lens that produces a real image on a distant screen of a nearby object. (That object is the image of the light source/LCD screen/slide produced close to the projecting lens by a condensing lens or lens system.)

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  • $\begingroup$ Regarding scan lens: "lens having f-theta distortion correction and telecentricity;" where "conventional lens distortion correction results in a scan position of f.tan theta for a scan angle of q. By designing into the lens the correct amount of barrel distortion, the scan position can be made to be f.theta;" and "a telecentric scan lens is one in which the chief ray of the focused beam is parallel to the optical axis at all scan angles." Given these assumptions, would you have a "projection lens?" $\endgroup$ – RG_Simpleton Nov 4 '16 at 21:31

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