卧式光学计英文翻译

卧式光学计英文翻译 With horizontal optical plan closed device ring gauges measured in internal threads diameter MC008 - JD2A projection horizontal optical meter 1, adopting new technology, additional wax screen brightness reading a magnifying glass, view is well-balanced, like faceted clear. 2, instrument accuracy, high measurement data is stable and reliable. Three, one will projection optical plan and take Chong tube in the machine tool, something can directly control processing size. 4, use optical projection reading method. Projection horizontal optical meter is precision optical mechanical length measurement instruments. It is to use standard LiangKuai compared with the measured thing tested a method to measure short-delay size, shape also use instrument brings the closed beta device comparison of internal dimensions measurement, is a factory, verification tester is standing, manufacturing tools, measuring tools or the processing precision parts of the workshop measuring instrument used by optical.Instrument measurement range (mm) : outside dimensions: 0 ~ 500, inner dimensions:13.5 ~ 300 use big measuring hook: 26.5 ~ 200, use quiz hook: 13.5 ~ 26.5 The main optical plan projection horizontal specifications: projection optical millions of totalmagnification 1650 times projection of magnification 18.75 times objective 1.1 times the reading a magnifying glass multiple optical mechanical magnification is 80 times partition board partition value 0.001 mm measuring pressure (N) 2 + 0.2 zero adjustment range + 0.01 mm projection horizontal optical plan 28h6 pipe outer diametermeasuring shaft with size phicolumn and measuring the inner diameter od with cap 6g6 outside dimensions measurement usually instrument accuracy: 0.25 muon m outsidedimensionsof the measurement and value stability: 0.1 u m when measuring the internaldimensions of the over-error of indication stability: 0.5 muon m diameter measuring cap with size: phi 6D the tailstock and projectionhorizontal optical plan with 28D aperture of tube workbench activities range: usually workbenchvertical journey (mm) > 100 workbench lateral movement range (mm) > 25 workbench micro-distance measuringdrum indexing value: 0.01 mm workbench load (KG) > 10 tail pipe budge each ride range: > 1.5 mm instrument shape dimension (mm) 1000 x 370 x 620 instrument weight (KG) 80 We restructuring horizontal optical plan within hole measuring device, make for screw pitch inside the measurement, a preliminary test and evaluation, this testing method, measurement results more stable, and universal length measurement instrument measured results are much closer to see the appendix. Below this inside measurement device calculation of the modification and testsquare Law stated below. Why Lens Design design used to be a skill reserved for a few professionals. They employed company proprietary optical design and analysis software whichwas resident on large and expensive mainframes. Today, with readilyavailable commercial design software and powerful personal (and portable) computers, lens design tools are accessible to the general optical engineering community. Consequently, some rudimentary skill in lens design is nowexpected by a wide range ofemployers who utilize optics in their products. Lens design is, therefore, a strong component of a well-rounded education in optics, and a skillvalued by industries employing optical engineers. Type of Course This is an introductory lens design course at the first-year graduate level. It is a nutsand bolts, hands一on oriented course. A good working knowledge of geomet-ric optics (as may be found in such textsas Hecht and Zajac's Optics or Jenkins and White's Fundamentals ofOptics) is presumed. Photographic lenses will form the backbone of the course. We will follow an historic progression (which also has correspondence fromsimpler to more complex systems). The code usedis Focus.Software's ZEMAX. andthe student must have access toa PC running ZEMAX. The math level required is not taxing: algebra, trigonometry, geometry (planeand analytic), and some calculus. A book list of references is provided in Appendix A. This course will provide you with three basic skills: manual, design code, and designphilosophy. The manual skills will include first andthird order hand calcu-lations and thin lens pre-designs. (Analysis skills are illustrated in Figure 1 .1).The code skills will include prescription entry, variable selection, merit function construction and optimization, and design analysis. The design philosophy includes understanding specifications,selecting a starting point, and developing a plan of attack. Consider the two optical systems in Figure 1.2. Both are viewing the same distant object. Both have the same focal length (so the image is the same size). System a is simple, whilesystem b is complex. If both systems yield thesame image size, why not use the simplersystem? Why does system b have extra lenses? Aside from image size, we assume that you want good, crisp, uniformly bright images across the entire field-of-view (FOV) over a flat recording format. System b will give that. System a will not. The latter's images will be of poor quality because there is inadequate correction for:The extra lenses in b are made fromdifferent kinds of glass to correct for color.The glass curvatures and thicknesses, and the air-spaces between them, help8 Chapter 7 Agenda.Detectors have sensitivity over certain color ranges, hence the next impor-Tant pecification concerns spectral bandwidth and location. Monochromatic designs or designswhere color does not matter are generally easier than polychro-matic designs. As the bandwidth of a polychromatic design increases, the design task gets harder. Designs can also become more difficult if the location of the bandwidth lies outside the visible spectrum. Here there are fewer choicesof mate-rialsfor color correction.The above mentioned design specifications are those of primary interest.However, there are several other constraints on designs. Theremay be volume,packaging, and/or weight constraints. There are constraints imposed by the ther-mal environment in which the optics will function. There may be constraints imposed by atmospheric or oceanic pressures. There may be constraints onglass choice imposed by humidity (or salinity) in the operational environment. Finally, there are fabrication, alignment, metrology, and cost constraints. It is preferable to design refractive systems with spherical surfaces rather thanaspheric surfaces. The latter are harder to make and test, and thus cost more. You do not want to design a system whose tolerances are so tight that it cannot be made. Again, tighter tolerances increase fabrication, assembly, andmetrology costs. If possible, you want to avoid systems that will be difficultto align; e.g., off-axis systems are harder to align than on一axis systems. They are alsoharder to test. You usually will have to find a compromise between what the customerwants and what he can afford.The optical design and analysis code ZEMAX0 from Focus Softwarewill be used as the main workhorse throughout this course. This user-friendly soft ware is both powerful and cost effective. In addition, the code is one used extensively in today's workplace. There are othermajor codes you will encounter in your profes-sional career such asCode-V0, Synopsis0, and SuperOslo0. However, it is impor-taut for the student to become adept in at least one major program. This chapter will provide a general introduction and basic orientation to ZEMAX. More detailed information can be found in theZEMAX manual.Before you can begin your design and analysis work, you need to enter an initial prescription into the code. There are four areas requiring input of basicinforma-tion aboutthe lens, aperture, field, and wavelength. As an example, we will enter a biconvex lens.Inserting a Prescription in the Lens Data Editor The main ZEMAX screen (Figure 2.1) shows a toolbar at the top with File, Editor,System, etc. Below that is a row of buttons designated as Upd, Gen, Fie, Wav, etc. Beneath that is the Lens Data Editor (LDE). Under Surface Type is a column on the extreme left with OBJ, STO, and IMA. With the mouse, move the arrow to the box just to the right of STO and click. The box (Standard) will be highlighted. (You can also do this using the arrow keys.) Now press the Insert key. You have just added a surface designated as 1 .Go to Standard next to the IMA row, click, and then press Insert twice. You have now added two more surfaces designated as 3 and 4. To the right of the Surface Type row are columns labeled Comment, Radius,Thickness, Glass, Semi-Diameter and Conic. Under the Radius column, move the cursor toSurface 3 and enter 100. Drop down to Surface 4 and enter -100. Under the thickness column, move the cursor to Surface 1 and enter 25. Drop down to Surface 3 and enter 10. Drop down to Surface 4 and doubleclick on the box to the immediate right of the data entry line. A submenu will appear. On the line labeled Solve Type,click on the arrow. Several optionswill appear. Select marginal Ray Height. (On the height and pupil zone linesthe number 0 should also appear.) Click on OK to exit this submenu. The letter M will appear in the little box. This solve will automatically locatethe paraxialback focal length since the object is at infinity. Go to the Glass column. Drop down to Surface 3 and insert BK7.Go tothe Semi-Diameter column. Drop down to Surface 3 and enter 25. Do the same on Surface 4.(Note that the letter U appears in the narrow column on the right. This indicates a user-defined quantity.) The semi-diameter specified here defines the actual size of the lens and how it is drawn. It does hot define the system aperture. This will be done inthe dialog boxes.This completes the information needed in the Lens Data Editor. Dialog Boxes Click on the Gen button. A submenu will appear. This is where the system aperture size is defined, glass catalogs are selected, and are chosen. Click the arrow on the lineAper Type. Another submenu willappear. Click on EntrancePupil Diameter. On the lineAper Value insert 40. This defines the system aperture.Note thatthe default units are millimeters. Leave this as it is.Had we not specified lens size inthe LDE, all surface aperture sizes would be automatically defined by the EPD just inserted. Also note that the default glass catalog is Schott. Click on OK to exit thissubmenu. Click on the Fie button. A new submenu appears through whichfield angles are selected. The zero field (on一axis) is already activated. Click on the little box on the extreme left to activate fields 2 and 3. Under the Y-Field column, move the cursor tofield 2 and click. Enter 7.07. Go to field 3, click, and enter 10. We have active fieldangles now at 00, 7.070, and 100. Click OK.Click on the Wav button. A new submenu will appear. One wavelength is already activated, but this is not the one we want. Move the cursor to row 1 under wavelength, click on the box, and enter 0.486. Activate two morewavelengths by clicking on the little boxes to the extreme left. Underwavelength, click on row 2 and enter 0.587. For row 3 enter 0.656. You have just inserted the three classic wavelengths (in microns)' used to define the visible spectrum.Theyare also designated as the F, d and C lines. In the column marked Primary, click onthe buttonon row 2. This designates the reference wavelength that will be usedinthe calculation of all first and third order properties.It may seem confusing at first, but with a little practice it will become second nature. The Lens Data Editor should look like that shown in Figure 2.2. (Toget ahardcopy of the prescription click on the Pre button } Settings } surface data} OK } Print.) To see what the system looks like, click on the Lay button. The diagram is shown inFigure 2.3. To obtain the scale for this diagram click on Settings. In the Scale.Factorbox insert 1 .Click on OK. The drawing reappears with ascale bar illustrated below it.Note that the Settings box allows you to choose the number of rays and also whatfiel ds and wavelengths to display. Explore these to gain a better under-standing of these options. Our object is at infinity, so we have collimated light coming inat the three selected field angles. But we are only seeing 25 mm ofcollimated space in front of the lens. The stop lies in the plane of the vertex of the first lenssurface. The stop diameter (40 mm) is smaller than the 50 mm diameter of the lens. Recall that the semi-diameter column in the LDE designates how big the surfaces are drawn on the SI units usemicrometer layout and nothing more. The image plane designated in the plot is wherethe parax-ial marginalray height is zero (defined by the M-solve). The back focal length is foundinthe LDE in the thickness column on Surface 4 and is95.068 mm. First Order Properties We are left with the question, "What is the effective focal length (EFL) and f-numberof the system?" To find out what these are as well as other first order prop-erties, click on the Sys button. This will bring up a chart with all the system infor-mation listed as shown inFigure 2.4We see that the EFL is 98.42 mm. The totaltrack=130.07mmand is the sum of thicknesses as measured from the first surface to the image plane. Note that there are three f-numbers listed. The first, image space f-number, is f/2.46 or EFL divided by EPD (object at infinity). The others will he discussed in Section At the main menu, clicking on Analysis provides the user with options for calcula-dons, plots and graphs that cover nearly every aspect of design analysis. What is available is summarized in Figure 2.5. For example, to find ray trace information, click on Calculations. Another menu box will appear to the right. Click on Ray Trace. Information on the marginal ray for both the real and paraxial rays is thendisplayed. Ray selection can be made by clicking on Settings. You can choose the object point's fieldlocation (H) and the ray pierce location in the entrance pupil (p). Both are given in normalized coordinates; i.e., they have values between 0 and 1.The more frequently used anal-ysis plot options can be accessed either through Analysis or by using the buttons Ray, Opd, Spt, and Mtf. As anexample, Figure 2.6 shows ray fan, spot diagram,and field curvature and distortion plots. In the heat of doing battle with aberrations, many different things are tried to opti-mize a design. It is very easy to lose track of how you got to a certain point. There-fore, documentation of each step of your design process is extremely important.This documentation should include not only what variableswere manipulated and what merit function structure was used, but also the step-by一step file names. For this course, all design homework will be handed in on a 3.5" floppy disk. The following character file name protocol will be used:the first four characters will be letters which will identify the type of sys-tem with which we are working;the fifth character will be a number(1-9) which will either identify sep-arate designs within the same type or different optimization approaches for thesame design problem;the sixth character will always be the letter o which stands forthe opti-mization path;the next characters)will be a number which designates a particularstep in the optimization path;the last character will be either the letter b or a, indicating the condition of the design before and after the optimization step. For example, TRIP2o4b indicates a second triplet design at the fourth step ofthe optimization process just prior to the new optimization run. It is also recommend-ed that each design problem be kept in a separately named folder. For example,the folder containing TRIP2o4b would be called "Triplet." The naming protocol also serves another important and practical function.It allowsthe instructor to keep his sanity. It is much easier to grade homework when every student follows the same protocol. When homework is handed in on disk, a script should accompany it. The script should describe what is being done at each optimizationstep. An example of scripting will be found in your second home-work assignment (in Chapter 3). All subsequent ZEMAX assignments should be scripted in a similar manner. When you insert data under the parameter heading Glass in the LDEyou willusually do so using a designation supplied by the manufacturer, e.g., Schott,Ohara, or Corning.ZEMAX has a library of glass designations in folders identi-fied by the company name. Different folders are accessed by ZEMAX only when the manufacturer is identified in the Gen menu. There is also a folder which contains commonly used IR transmissive materials such as zinc selenide. Finally,there is a miscellaneous folder that is a mixed bag of different materials including air, water, and plastics. Glass in ZEMAX is not stored as a refractive index versus wavelength look-up table. Rather, glass is stored as a polynomial function; it is the first six coeffi-Section 2.8: Odds and Ends 19dents of this polynomial that are stored. If you click on the Gla button, the glass catalog menu will appear. Thecoefficients for any particular glassare represented by the numbers just to the right of the AO-AS alpha-numerics. ZEMAXuses these coefficients to calculate the refractive index at any selected wavelength within the valid domain of the polynomial. Of course these coefficients are based on a poly-normal fitto meascered data over a certain spectral range. The ZEMAX glass catalog provides explicit index data only for "d”light(λ=587 n m). If you want to find out what the indices are for the wavelengths you have selected, you must click on Pre } Settings } Index Data } OK. We saw that there are three distinct f-numbers shown in ZEMAX's General Lens Data list. The traditional f-number is given by the "image space f-number." What about the other two? Consider a ray parallel to the optical axis incident on a thin singletat a height y as shown in Figure 2.7.image space f-number:EFL paraxial working2 tanU' Here we see that f-number is related to the bend angle on the ray coming to a focus in image space. We'll call this the "paraxial working f-number." It will be the same as the "image space f-number"only when the object is at infinity. If the object is at some finite distance, then the bend angle U' will be different resulting is called the"working f-number." It is in a different effective f-number.The last f-number ZEMAX defined as:working 2 si n U.This f-number applies to real aberrated systems where U'departs from its ideal unaberrated path.We will talk more about paraxial and real raysin Chapter 4 Consider a unit circle as shown in Figure 2.8. Its area is 3.1416 units. What is the subradius that will enclose has this value Subrad‘=0.707’ The subradius 0.7071 divides the unit circle into two regions (an inner circle andan outer annulus) having the same area. There aretwo traditional applications of this in lens design and in ZEMAX. The first is in selecting where in a circular object field rays emanate;the second, where in the circular entrance pupil rays are incident. When we use the dexult merit function inZEMAX to set up the ray ensemble for tracing through the system for optimization, you'll see that use is made of this subradius. Back in Section 2.2.2 we selectedfields of 00, 7.070, and 100. The middle value was not an arbitraryselection; it was 0.707 times the maxi-mum field angle.In the last chapter you gained some familiarity with ZEMAX. In this chapteryou willstart using it. The problem assignment in Section3.6 will walk youthrough an extensiveexercise set involving the singlet from the first homework. Part of that exercise will involve bending the lens, while maintaining power, to minimize spherical aberration.You will also be using an aspheric surface to drive the spher-ical aberration to zero.Much of this chapter providesbackground material for this ZEMAX exercise. The prescription information fed into ZEMAX and the data for manual calcula-dons will follow a specific sign convention. Figure 3.1 will serve as a guide and reminder of those conventions. Radius of curvature, R, and curvature, C[=1/R],are positive if thecenter of curvature lies to the right of the surfacevertex; nega-tive if the center is to the left of the vertex. Shown in the figure are the front and rear principal planes. The former lies to the right of the first surface vertex and the separation (cS) is positive; the latter (b') is negative. The effective focal length, f ;(measured from the rear principle plane) is positive. The front focal length, f, is negative. The object distance (l),measured from the front principal plane, is nega-tive. The image distance (l'), measured from the rear principal plane, is positive. A ray angle is positive if it has an upward slope; negative if downward. Figure 3.2 shows five lenses, all of which have the same focal length or power.The shape of the lens is defined by the shape factor, X. It is defined as:(C,一Ca) An equi一biconvex lens has a zero shape factor. A plano一convex lens has a一1 s hape factor while a convex-plano lens is+1 .In the exercise, the lens shape will be21 changed, and the amount of spherical aberration in image space will also change.Also note that the principal planes will shift position relative to the lens for differ-ent bendings. An important property of an optical surface is surface sag, which is illustrated in Figure 3.3.In optical shops, the radii of curvatures specified in your design will be verified by measuring their sags (using a device called a spherometer). Sag will also showup in our discussion on aspheric surfaces. A convenient approximation is now derived. Rewriting Eq. Aspheric Surfaces All of the optical surfaces we have dealt with thus far have been either flat or spherical. We must now enter the realm of aspherics. Such optics play a very important role in optical systems. For example,almost all reflective astronomical telescopes have at least one asphericcomponent, either on the primary or second-ary. In most cases both components are aspheric. Closer to earth,the Kodak disc camera uses injection-molded glass elements, some of whichare aspheric. The primary reason for using aspheric components is to eliminate spherical aberration(especially when there is a constraint on the number of optical surfaces and indices allowed). However, most designers still prefer to use spherical rather than aspher-ical surfaces. The reason has more to do with fabrication issues than anything else. Aspherics are much harder to make and measure. More time and skill are required of the optician and metrologist, thereby driving up costs. Consequently,the use of aspherics is limited to cases where (a) there is no other way, or (b) a trade-off study has shown it to be cost effective in the long run. Finally, it should be noted that the useof an aspheric does not change any of the first order design characteristics(cardinal points). All paraxial data remains thesame. The modification made to an optical surface designating it as aspheric is the presence of the conic constant. We will begin by deriving the standard form employed ingeometrical optics. Consider the diagrams in Figure 3.4. On the left we have a circle concentric with the origin of the coordinate system.the equation describing the circle is:Now we translate the coordinate system as shown on the right. The origin of thecoordinate system is now coincident with the vertex of the optical surface. The equation for this translated circle is given by: The region of the surface we are interested in is the darkened arc passing through thevertex.The equation describing a conic asphere is given by:where P=1+K, and K=一e2, and a is the numerical eccentricity. (Note that e2=(a一b2)la2, where a is the semimaj or, and b the semiminor axis of the conic respectively.) The conic constant is identified with P by some authors(Kingslake), and K by others (Malacara). One must be careful to ascertain which author is using which constant. This text uses K as does ZEMAX. We now use the quadratic equation to solve Equation 3.8 for:(where when its light is reflected from a spherical mirror. This reduces the detail in the image. A parabolic mirror, on the other hand, introduces no spherical aberration. Imagery is sharper. In the classical Cassegrain telescope, the primarymirror isparabolic. The secondary mirror is also aspheric and hyperbolic. A hyperbola has two foci. As illustrated in Figure 3.6, a ray directed toward the focus behind a hyperbolic reflector will be redirected toward the primed focus. In theCassegrain telescope configuration,the parabolic focus coincides with the hyperbolic focus FH as shown in Figure As a designer you must have a good feel for the manufacturability and metrology of your optics. It may be the best diffraction-limited design ever——but if it can not be built what's the point. Also, it may prove difficult, or impossible, to align and test. Meeting spec is not the only criteria of a good design. Consequently, when aspherics are employed, be mindful of the fabrication and testing issues that arise,as well as the added costs and increased delivery times such surfaces usually entail. When discussing an aspheric design with people in the optics shop, be prepared to provide information on how far the aspheric surface departs from a spherical surface at full aperture (or marginal ray height). This is illustratedin Figure 3.8. The mathematical description of a spherical surface, Equation 3.7, can be recast into an expansion as was done for the aspheric surface in Equation 3.12.(The form can be quickly obtained by setting P=1 in Equation 3.12.) Of interest is the difference between Equation 3.13 and Equation3.12 whit is the departure from sphere:when its light is reflected from a spherical mirror. This reducesthe detail in the image. A parabolic mirror, on the other hand, introduces no spherica Imagery is sharper. In the classical Cassegrain telescope, the primarymirror is parabolic. The secondary mirror is also aspheric and hyperbolic. A hyperbola has two foci. As illustrated in Figure 3.6, a ray directed toward the focus behind a hyperbolic reflector will be redirected toward the primed focus. In the cassegrain telescope configuration, the parabolic focus coincides with the hyperbolic focus FH as shown in Figure 3.7. As a designer you must have a good feel for the manufacturability and metrology of your optics. It may be the best diffraction-limited design ever一but if it can not be b uilt what's the point. Also, it may prove difficult, or impossible, to align andtest. Meeting spec is not the only criteria of a good design. Consequently, when aspherics are employed, be mindful of the fabrication and testing issues that arise,as well as the added costs and increased delivery times such surfaces usually entail. When discussing an aspheric design with people in the optics shop, be prepared to provide information on how far the aspheric surface departs from a spherical surface at full aperture (or marginal ray height). This is illustratedin The mathematical description of a spherical surface, Equation 3.7, can berecast into anexpansion as was done for the aspheric surface in Equation 3.12.(The form canbe quickly obtained by setting P=1 in Equation 3.12.) Of interest is the difference between Equation 3.13 and Equation3.12 which is the departure from sphere:This exercise consists of 11 parts. Its purpose is to give you some initial experi-ence in the use of ZEMAX as a design and analysis tool. You will alsostart learn-ing howto select variables and build a merit function for optimization.You will start by entering the lens used in the Homework for Chapter1and the radii calcu-lated there. Use the same wavelength and dimensional unit (namely mm). Also, use the M-solve on the thickness after the second lens surface. Surface No.l will be the first glass surface of the lens. (So initially you will have lines O，STO[which is s urf no.l」，2, and IMA.) The merit function editor (MFE) is accessedby clicking on Editors } Merit Function. Get in the habit of inserting all the Seidel operands as a means of keeping track of their values. (While on the first operand row, hit Insert several times for more rows to appear.) Whether operands are used in the optimization will be determined by the number under the weight column (keep moving cursor to rightuntil you see the Weight, Value, and%Contribution column headings). Initially your MFE should look like Table 3.2. Currently, all operands in the above table are turned off. The EFL and Seidels will be computed for wavelength 1 (the only one we're using). Insert1 under the wavelength column for all operands.Load the lens from Homework for Chapter 1.That was a thin lens com-putation. Now use a real thickness: 4 mm. Field angles are: 00, 3.50,50,andλ=0.587. Units are mm. Put M-solve on thickness of the second glass surface. Note: EFL and f-number are not quite the paraxial values. This is due to theinsertionof real thickness..Use f-number solve on R2 to tweak back to paraxial. Double click (DC) on R2 Select f-number Insert 10 SING101 a Check out spherical aberration: look at the ray fan plot; spot diagram;Seidel value. Bend lens to reduce spherical. Remove F-solve on R2. (DC on R2, select variable). Make R} variable.SING1o2b } OPT } SING1o2a Note: SPHA has dropped from 1.716 to 1.09λ!column headings). Initially your MFE should look like Table 3.2. Currently, all operands in the above table are turned off. The EFL and Seidels will be computed for wavelength 1 (the only one we're using). Insert 1 under the wavelength column for all operands. Load the lens from Homework for Chapter 1.That was a thin lens com-putation. Now use a real thickness: 4 mm. Field angles are: 00, 3.50, 50,andλ=0.587. Units are mm. Put M-solve on thickness of the second glass surface. Note: EFL and f-number are not quite the paraxial values. This is due to theinsertionof real thickness.Use f-number solve on R2 to tweak back to paraxial. Double click (DC) on R2 Select f-number Insert 10SING101 a Check out spherical aberration: look at the ray fan plot; spot diagram;Seidel value.Bend lens to reduce spherical. Remove F-solve on R2. (DC on R2,select variable). Make R} variable. Note: SPHA has dropped from 1.716 to 1.09λ! correct aberrations over the FOV. The result will be high-quality imagery over a flat recording surface (whether that be film or a CCD). Aberration and Imagery Figure 1.3 a shows a resolution target being imaged by a "perfect" optical system. The image is simply a scaled version of the object. In Figure 1.36 we have a point source being imaged by an imperfect optical system.The resulting image is a fuzzy blob instead of a point. If we now combine the two so that we image the resolution target with the imperfect system, the image is of poor quality, as illus-trated in Figure 1.4. What has happened is that we have essentially replaced every image point in Figure 1.3 a with the blob image inFigure 1.3 b. Fundamentally, aberrated point images that degrade image quality arecaused by the nonlinear behavior of Snell's Law. Aberrations arise when the angle of inci-deuce of a ray with the normal of an optical surface starts getting large.This can happen in two ways for a givenradius of curvature. For a ray parallel to the optical axis, as per Figure 1.5a and b, the angle of incidence increases as the ray height increases (from 3.50 in Figure 1.5a to 170 in Figure 1.5b). If the ray strikes at the same height but from a different field angle, the angle of incidence can increase (as shown for the upperray from 3.50 inFigure 1.5 a to 230 in Figure 1.5 c). When both conditions happen at the same time, the angle of incidence is even larger(from 3.50in Figure 1.5a to 370 in Figure 1.5c}. For the lower ray in c and d,the angle of incidence decreases. Butnow there is an asymmetry between upper and lower rays, which is indicative of oaxisaberrations. As a system f-number decreases and field angles (and spectral bandwidth)increase,the complexity of optical systems (required to maintain good imagequality) also increases. Figure 1.6 shows a qualitative plot of optical system types as a function of f-number (x-axis) and field angle (y-axis). For a 1/40 field at f/10,a simple parabolic mirror would suffice. However, for a field of200 at f/2, a six-element double-Gauss lens might be employed. Before any design can commence, the designer must have a clear understanding of the customer's requirements. This is not as straightforward as it seems.There are times when the customer is not sure of the requirements. This may lead to unexpected specification changesafter much design work has alreadybeen done.In this case, the designer must take an active role in helping the customer solidify the requirements. At the other extreme is over-specification. Here the customer has placed unrealistic constraints on the design. For example, tolerances may be beyond current fabrication or metrology capabilities. Here again the designer must interact with the customer to arrive at realistic specifications. Field coverage depends on the format size and effective focal length (EFL)of theoptics. For example, the format size may be fixed by the use of 35mm film,or an 8x6 mm CCD chip. The customer will say how much of the outside world or sceneis to fit on the given format. This defines a certain FOV or field angle which then dictates an EFL. One, the measurement device modification Modification method is simple, as long as take down horizontal optical plan inside quantityhead 1. mount a strip steel ball measuring head，2.within the form screw pitch test devices(Figure 1 )Measurement of the first two distant diameter size, can press ball next type calculation type of D—Round steel ball diameter, mm t—Pitch, mm; 2/a—Tooth-type half horn; To pitch for 1 ~ 6 mm metric thread application under the ball diameter watch list Units:mm t Minimum diaBiggest diametPriority to adopt size ra meter er nge 1~1.5 0.5774 0.8660 0.722 0.75~0.80 2~2.5 1.1547 1.4434 1.299 1.25~1.30 3~3.5 1.7321 2.0208 1.876 1.80~2.00 4~4.5 2.3094 2.5981 2.454 2.30~2.50 5~6 2.8868 3.4642 3.157 3.20,3.50 Note: according to universal length measurement instrument attached measurement using steel ball head as a priority. Round steel ball can choose ball bearings ball to binder (epoxy resin or metal glue) or soldering fixed axis stem. Second, instrument zero adjustment calculation of basin block combination size Instrument zero adjustment method and abbe universal length measurement meter test method of adjusting the same diameter. Test the actual situation of thread ring gaugesas shown in figure 2. Can see from figure 2, when in measuring thread ring gauges, and not in a horizontal position, but with a horizontal position constitute a thread litres Angle Angle. The figure 2 is simplified to figure 3. Can see from figure 3 M and measuring axis diameter in the direction of the axis P is not coincidence between Angle, there is a measureφ, as this will cause the phi error. Whenφ phi and corner cutting very hour, calculation, this error is proved, please refer to "work" 76 years measuring 25 pages, vol. 4 in GaoKeMing comrades being measured about measuring axis in rift diameter line produces error computation part. Figure 4 shows is a steel ball and threads, toothcontact， Can be obtained by figure 4 the following various relations Will AB, AC into (1) type, get Type the name of internal threads in -- d2 diameter Below zero adjustment according to the measurement instrument axis LiangKuai combination size needed calculation formula for derived. Figure 3 knowable by Figure , knowable by Will (,) into (1) type, get The type of d2, t, a, are nominal size, D is known ball diameter, calculated from theLiangKuai combination size L, to adjust the horizontal optical plan, can compare testring gauges of internal threads diameter. This is in no universal side long instrumentand threaded tooth-type gap under the condition of KuaiGui attachment and dosage of distant block ball diameter, can also measure to positioning Try ring gauges of internal threads diameter Exhibit: horizontal optical plan and universal length measurement instrument measurem ent result comparison