Патент USA US2409330код для вставки
Oct. 15, 1946. 2,409,328 R. S. WILDER ILLUMINATING- UNIT FOR OPTICAL PROJECTORS Filed Oct. 26, 1944 JP A E NW m iw..AMlI/vim' 34 h mania?’ I Patented Oct. 15, 1946 2,409,328 UNITED >_SJTATES PATENT" ‘ OFFICE G'UNITFOR OPTICAL I ‘ PROJECTORS . Raymond S: ,Wilder, Waltham,,Mass.. Application October 26, 1944", senarno. 560,138?‘ a claims; (01. arr-24)" 2 This invention pertains to optical‘ instruments, especially to an optical‘ comparator-or- micro-pro objective lens support of'such- an instrument and which is designed to‘ carry a series of independ ent lighti sources'disposed- symmetrically in a cir jector designed in particular to project onto , a screen, irr juxtaposition, enlarged images of’ a workpiece (for‘instance a- small machine part) and‘ a‘standard part with which the workpiece is to be compared. Forloptimum accuracy of‘com parison it‘ is essential that the light“ source be intense, in order to produce the desired contrast‘ . unit easily‘ applicable to andfremovablefrom the , cle coaxial with the optical axis of the‘lens. A further object is‘ to provide an instrument‘ of the class‘ described‘ having“ provision‘ for so‘sup- ‘ porting a‘series of incandescent lamps ofcom~ mercial type as to provide substantially» uniform between image and background, and also‘v that 10 illumination for- that surface of‘ the workpiece theillumination be uniform and such that, irreg > which is presented‘ toward the objective‘ lens. ular shadows, halos- or “ghost” images may not Other- and‘, further‘ objects and advantages of the be: formed, Customarily the light source em invention'will be~pointed~out in‘the following more ployed in such instruments is a sin'ge incan detailed description‘ and by referenceto the ac descent lamp arranged to‘ illuminate the back‘ of 16 companying drawing wherein the object, that‘ is to say, that‘ side of‘ the object Fig. 1 is a small scale, diagrammatic vertical‘ which is remote from the objective lens, and‘ section through a micro-projector of‘ a- commer thus the image formed on‘ the screen is merely cial type‘, showing the projector provided-1 with the a shadow image. However,‘ when comparing cer improved? illuminating» unit‘ of: the present‘ inven tain types of‘ work, for instance- pieces having; 20 tion; 1 . projecting portions, cavities, etc, it‘ is not‘ possible Fig; 2 is a side elevation, to larger scale, of to obtain‘ the desired results merely by‘ shadow the light unit; images produced by transmitted light; In such Fig. 3' is a vertical section substantially on the cases it is desirable to direct light’ from a‘ suit able source against the forward surface of the 25 line -3--3 ‘ of Fig. 21; , Fig; fl is a plan view of’ the ‘device. at Fig. 2:‘ work, that is to say, that‘surf‘ace which is toward the objective lens,‘ so that, an image is formed‘ by reflected‘ light, or partly by transmittedyand and; Q Fig. 5 is a bottom'pl‘an view, with partsiinihori zontali section, substantially on. theline 5-—-5 of partly by re?ected light. , However, the use of ‘re Fig. 3; 7 ?ected light is attended with; substantial di'?i 30 Referring to “the drawings; thelnumeral. I‘. dcs~ culties, .especially by reason of"the space I-iinita ignates one of: pair of. parallel posts or‘ stand; tionsof such an apparatus, in’ particular‘the pres‘ ards- rigidly" connected together and which form‘ ence of the objective lensandf its' support be a. supportior' a; vertically'mova ble horizontal arm» tween the work-supporting‘ table and the-‘screen, 2 which carries‘ thew worktable- 3; the, latter being Under these conditions, the re?ected light; as 35 of" glass or other" suitable transparent material; heretofore provided, has been non-uniform, with The posts: I alsosupport a bracket: lwhiclrv car-' the result: that‘ troublesome irregular shadows, halo eifects, etc. are produced which interfere ries-atruncatedlconical hollow‘ posti. > At‘its up-v greatly with-theaccurate-comparison OfilihGj-‘W?l‘ke per end. this post 5 is; provided witha; socket: for the.‘ reception of any one of. a plurality of in piece and standard: part: asztheir'images‘i appear: 40 terchangeable objective-lens sets . of 1 different magnifying power,‘ respectively. Each lens set has The principal: object of theinvention. is to..=pro a‘baseportion 6‘ (Fig. 3')? each of said base'por Vide. an. illuminating unit, applicable to an in; tions: being‘ at the same-external. diameter so: as strument of.‘ the, kind referred to,. bymeans: of to‘l?t into the-.socketthc.‘ post 5. The‘ objec which the front surfaces: ottthe workpiece; and 45 tive' lens;_ when thus» mounted, hassits axis. ver standard: part may be intensely illuminatedcby tical? and is: designed! to. direct an 1. image of van light of‘ such uniform ‘character. as to provide object‘ mounted on they worktable onto a. mirror sharp, clear and substantially- shadowless; images 1' which re?ects thi'simage- ontcra screen. 8iwhere onthe screen, A further‘ obiect is; to. provide an itlmay be observed; The mirror ‘I ishousedwith~ onthe screen; ' ' . ‘ ‘ ‘ illuminatingunit designed to form animage. oi ' the workpiece, by re?ected light, which will. be substantially free. from‘ halo, “ghosts” or‘ other troublesome effects‘such ascommonly resultfrom the use of. a single light! source-j-forthispurposes. A, further object. in. a, darkaboac 9: whichsmaytifr desired; form the At‘. their upper ends the posts’ or standards. I support. a bracket H] which carries adjusting ‘mechanism H‘ by means; of which.‘ the position of theworktable ‘ support. for‘ the posts or‘ standards. l. tov provide an. illuminating 75.5 may the vertically adjusted“ relatively to; the ob 2,409,328 4 jective lens. The bracket It may also support a housing l2 within which a light source, for in stance a single incandescent lamp, having its ?lament at the optical axis of the objective lens, and which furnishes a beam of light directed onto the worktable by condensing lenses within the lamps are out of the ?eld of vision of the ob jective lens so that images of the ?laments are not formed by the lens. Preferably the outer wall IQ of the unit extends upwardly above the top of the lamps 26 so as to protect them from the housing l2 so as to form an image of the surface of the wall [9 is of re?ecting character mechanical injury. Preferably, also, the inner thereby to utilize the light from the lamps in The base 60f each objective-lensset'is a heavy the'mosteffective way. Since the outside dimen hollow cylindrical part-having a bottom ?ange 10 sions of the illuminatingunit are so small it may 6a which seats in the socket in the top of the post _ readily be mounted upon the lens tube I3 and 5. Within this hollow cylindrical member 6 there ' ‘beneath the work table without interfering with the normal operation of the apparatus, and the is mounted a cylindrical tube l3 in which the ob object by transmitted light. jective lenses l4 and I5 are mounted. Q ' "work table may be adjusted downwardly until The structure thus far described is of substan 1.5 the work is very close to the light source if de tially usual type, designed to form a shadow image "sired. ~ In use, the .unit..l6 is slipped down over the of the workpiece by transmitted light, it being. lens-supporting tube," and when the lamps 26 are understood that the lamp within the housing vl2 ' may be provided with a switch so that this light " lighted‘ (being supplied with current from any source may be used or not as desired. 20 suitable source) a powerful beam is directed up wardly against the workpiece resting on the table I In accordance with the present invention there 3. Although the several light sources, constituted is provided an illuminating unit [6 for use with by theindividual cylindrical lamps 26 are inde any one of the objective lens sets. This illumi nating unit comprises an annulus l'l, whichmay pendent, yet by reason of the arrangement of be a casting, or which may be made by machining 25 these light sources in closely spaced relation and symmetrically in a circle, the light thrown onto it from bar stock, Or which, if desired, may be of the workpiece is substantially uniform; moreover, the angle of incidence of the light from the sev eral lamps is the same so that allsides of the ?ning an aperture of a size to receive the upper 30 workpiece are equally illuminated and the image of the workpiece (formed by the objective lens) end of the lens tube [3, preferably with an easy is uniformly bright, free from shadows, distor-v sliding ?t. To limit downward movement of the suitably moulded synthetic resin or the like. This annulus I‘! has inner and outer radially spaced cylindrical walls l8 and [9, the inner wall de illuminating unit relatively to the tube IS, the tions, halo effects, etc., thus providing the op timum condition for comparison of the images of as an inwardly directed ?ange or shoulder 20 at 35. the‘ workpiece and a standard part. It may be noted that the sources of light are, the upper edge of the inner wall IS. The walls [8 commercial incandescent lamps, readily availand H] are radially spaced apart a distance such able at reasonable cost, so that the illuminating as to provide an annular chamber of substantially unit is relatively cheap to make and to maintain the minimum radial dimensions capable of ac commodating commercial incandescent lamps of 40 and in these respects is far superior to devices heretofore suggested in which special annular the type illustrated and as hereinafter described, lamps are depended upon to provide the light. the walls l8 and I9 being united by an annular, Moreover, this improved unit is readily applicable horizontal web 2| (Fig. 4) in which there is to and removable from a lens-supporting tube so formed a series of circumferentially spaced bores that the interchange of lenses is not interfered with ‘their faxes vertical. These bores are ar with. When it is not desired to use re?ected light, ranged symmetrically with reference to the axis the unit may be removed for storage, leaving the of the annulus and, as here shown, there are ten apparatusexactly as it was before application of; of these bores spaced 36° apart; a greater or the illuminating unit. I I lesser number of such bores may be provided, if While one desirable embodiment of the inven-' desired, but it is believed that there should be at 50 unit is provided with a suitable stop, here shown least four of these bores. " Each bore has mount ed within it a socket 22 of a standard kind; such as is employed for holding an-incandes'cent lamp of - commercial type. Each of these sockets is tion has been shown by way-of examplepit is to be understood that the invention is to beregard ed. as broadly inclusive of any and all modi?ca tions which fall within the scope of the appended; provided with an insulated contact 23, here shown I claim: 7 ' ' as resiliently supported for engagement with the 1. A micro-projector of the kind wherein the center contact of the lamp, the wall of the socket image of an object supported upon a work table being grounded on the annulus I‘! if the latter is is projected onto a screen by an objective lens of metal and if not, being connected to a suit able electrical conductor (not shown). Obvious 60 mounted in a tubular support, characterized in having an illuminating unit mounted on the lens ly, if desired, screw type sockets may be used in support and comprising an annular housing hav stead of the push type sockets here shown. The ing an inner cylindrical wall de?ning an aper contacts 23 of the several sockets are connected ture designed to receive the upper end of the axial by individual insulated conductors 24 to- a con cluctor 25 which extends concentrically around ' cylindrical walls united by a radial web and spaced the tube“ below the annulus l1 and out of con apart a distance only su?icient to accommodate tact with the tube when the illuminating unit is the lamps employed, the inner wall‘ de?ning mounted on the lens-supporting tube. The sev a stop shoulder engageable with the end of the eral conductors 24 pass through'openings in a disk tubular support to limit axial movement of the 24“ ofinsulating material which holds the con_. 70 housing, the housing also having a, radially ex ductors 24 inwproper relative positionv and which tending web portion provided with a. series of also holds the conductor 24a outwardly and away spaced lamp sockets whose axes ‘are parallel to from the tube ‘l3. " ' that ofv the housing, the sockets being disposed Each socket 22 receives a lamp 26, the axes of symmetrically with respect to the optical axis the sockets being so located that the ?laments of 75 of the lens and being so spaced laterally- from claims. - - _ 5 2,409,328 said axis that lamps disposed inthe sockets are out of the ?eld of vision of the lens, the housing also having an outer cylindrical wall of a depth greater than the heights of the ?laments of lamps disposed in the sockets, said outer wall being of an internal diameter such as to a?ord rap-proximate ly just sui?cient space for the lamps arranged in the sockets and having an inner re?ecting sur face. 2. An illuminating unit for use in a, micro projector of the kind wherein the image of an object, supported on a work table, is projected onto a screen by an objective lens mounted in a tubular support, said unit comprising an annulus having a central aperture of such diameter as to receive the tubular lens support, the annulus hav 6 7/ ing inner and outer radially spaced coaxial walls united by a radial web, the inner wall de?ning the aperture which receives the tubular lens support, said inner wall having an inwardly directed stop shoulder engageable with the end of the tubular lens support thereby to limit axial movement of the annulus relatively to the support, the web having therein a, series of circumferentially spaced sockets designed to receive incandescent lamps of commercial type, the sockets being disposed symmetrically relatively to the axis of the annulus and the outer wall of. the annulus being of a depth to provide a protective shield for lamps mounted in the sockets. RAYMOND S. WILDER.