US2394649A - Scanning apparatus - Google Patents

Description

' SCANNING APPARATUS Filed April 29, 1942 2 Sheets-Sheet 1 INVENTOR CHARLE; J. YOUNG ATTORNEY SCANNING APPARATUS Filed Apfil 29, 1942 2 Sheets-Sheet 2 INVENTOR (HA RL E6 J. YOU/V6 A TTORNE Y Patented Feb. 12, 1945 Charles J. YoungQArdmore, la., assignor to Radio Corporation of America, a corporation of Delaware Application April 29, 1942, Serial No. 440,923

12 Claims. (Cl, 178-71) My invention in general relates to apparatus for the transmission and reception of intelligence, and more particularly to a form oi facsimile apparatus.

A number of diflferingtypes of facsimile scan nershave been known and suggested in the prior art, and by the term scanner isincluded receivmg means as well as transmitting means. Popular amongst the previously known scanners is an arrangement whereby the material to be transmitted is placed on a rotating drum, and either the drum is traversed with. respect to the pick-up unit, or vice versa. Also, there are other arrangements in which relative motion between the scanning element and the scanned material is necessary, and heretofore where these elements have been inclosed'it has resulted in a more or less inaccessible or awkward apparatus. cordingly, it is one of the objects of my invention to provide an arrangement which, although entirely inclosed, and having no outwardly movmg parts, is easily accessible, substantially dust tight, and otherwise desirable.

In the heretofore known prior art 'the scanning of material to be transmitted has been initiated by the engagement of a clutch member between the driving motor and the moving elements, or the scanning has been stopped for the purpose of adding material to be scanned to' the moving elements by the disengagement of 'a clutch. This clutch naturally can be a sourceof great trouble since it must not only be accurate, but must be definitely energized with considerable force in order to' insure accurate engagement. It is the object of the present invention to provide a device in which no clutch member will be necessary between the scanning drum and the driving means in a facsimile apparatus; Again, in the arrangements previously known to the prior art, and wherein the material to be scanned has been fastened into position, and wherein the signals developed depended on the reflection of light from the surface to be scanned onto photo-electric means, varying thicknesses of material containing the intelligence affected the correct focus of the lens systems associated with-the pick-up or scanning unit. Itis another of the objects of my invention to provide an apparatus in which the material to be scanned will, of necessity, be accurately and definitely focused with, respect to the optical systems ofthe pick-up or projection means.

At the present time, facsimile apparatus has.

scansion a military standpoint since, for instance, in the 7 case .of airplanes, it is preferable to be able to transmit materials such as maps, or even written intelligence and the like, from an observing plane to its base, rather than depend purely on photographs, since there is no definite assurance that the plane'ultimately will return toits base,.and where photographic means are used this means that a flight has been wasted, as well as a plane,

unless the'plane returns. On the other hand, by utilizing facsimile apparatus the flight has not transmitted from the plane at the time that it is picked up by the plane, whether the plane been rendered useless if the material can besubsequently returns to its base or not. It will be appreciated that such apparatus necessarily must be not only accurate, but must be compact r after appended description, and it will be appreciated that the foregoing have been listed only as indicative of some of the objects and purposes tating double optical system, which not only rotateswith respect to the cylindrical surface, but also is caused to traverse along the axis of the semi-cylinder. Appropriate means are provided been found to be of considerable interest from for causing this optical system to direct. a beam of light onto the material to be scanned, and in the case of a transmitter photo-electric means are provided which will pick up light reflected from the surface which is scanned. Since a double optical system is provided, that is to say, since two optical systems apart from each other are provided, scanning is continuous despite the fact that the surface against which the intelligence is held '15 a 180 semi-cylinder. The driving means for causing the optical systems to rotate as well as traverse are mounted and travel along with the optical systems, although it will be appreciated that separate driving means might be used for rotating and traversing the optical systems. An appropriate ore-amplifier also is provided and rides along with the optical systems during their traversal of the surface to be device utilizing my invention.

' Fig. 3 is a view showing other details of a device My invention will best be understood by refer- 5 ence to the drawings, in which: Fig. 1 is a schematic showing of a device in accordance with my invention.

Fig. 2 is a partial illustration'of a side view of a according to my invention.

Fig. 4 is a partial view of a dual scannin unit.

Referring to Fig. 1, there is shown a schematic view of a device embodying the principles of my invention. In this view. av semi-cylindrical transparent merfloerfiil has placed in intimate contact with the outer surface thereof a planar material H on which is recorded the intelligence to be transmitted, and of which scansion signals are to be developed which are representative of theoptical values thereof. ,Positioned so as to be in scanning relationship through the semi-cylindrical member it is a dual scanning arrangement contained within the rotatable element l2 which may also contain a pre-amplifier. In general, the scanning arrangement will comprise two complete scanning units disposed 180 apart with respect to each other and adapted to be rotated by rotation of the shaft l3. These scanning units each contain a light source with means for directing the light from the source through an aperture and through the transparent support-' ing member i onto the material to be scanned. Positioned adjacent the light source and hav- .ing an optical system adapted to project light reflected from the surface of the image to be scanned is a photo-electric member and the reflected light may find its way to the directing optical system through another aperture. This arrangement will be shown schematically in somewhat greater detail in Fig. 3, and since such devices per se have been known heretofore, and since the particular arrangement of For purposes of simplicity the means of energizing the various elements of the scanning unit have not been illustrated, as these means will be well known to those skilled in the art. .By way of example, the lamp in each scanning unit might be energized by means of running the leads thereof to a pair of slip rings and impressing the necessary voltage and current onto the sli rings to light the lamp. Similarly, the biasing voltage. for the photo-electric cells might be impressed in the same manner. Such means are well known to those skilled in the art, and do not need elaboration. v

The shaft I3 is connected to a gear 28, the

gear being driven by the worm 28, the latterbeing rotated by means of motor means 22. The

worm 2| also rotates a gear 23 which isjoined through a shaft 24 to worm 25, the latter meshing with gear 26. The gear 26 is fixed on a shaftcontaining an elongated lead screw 27.

There has been shown as partially broken-away 70 a housing 30, the purpose of which is to act as a mounting means for the motor 22, the lead screw 21, the gear 20, the associated dual scanning arrangement l2, and a pre-amplifier ma- The housing with these elements is supported in 7 that. the shaft 34 will rotate and will bring half such a manner that the housing can bemoved along .in the device with all of the elements recited, and such mounting means will be more fully illustrated in Fig. 2. The supporting housing on which is mounted not only the driving motor means 22, but the supports for the dual scanning apparatus having the casing l2 and also for the pre-amplifler I00, has been broken away in this figure for purposes of clarity. It will be appreciated, however, that the two sections which are identified by the numeral 30 relate to one and the same housing,

part of which is illustrated in somewhat more detail hereinafter in Fig. 4. n

Positioned adjacent the lead screw. 21 is a pivoted at 31 and joins the shaft 3 at the position 31. At the extremity of the arm .35 which is remote'from the position 31 there is connected a spring means 38. co-operative relationship with arm 35 is a second pivoted leverarm to which is pivoted at the point AI, and which also has fastened to the end thereof the spring 38. Substantially at the end of lever. arm' lfl remote from its connection to the spring 38'is a push button or lever means 62 which contains a slot through which 'passes the lever arm Ml. l

Positioned in co-operative relationship with the lever arm 40 is a third lever arm arrangement which is pivoted at the point 5|. A sub- 'stantially L shaped section of this third lever arm has the lower portion thereof running under the lever arm 40 and on the other side of the pivot it this lever arm continues and forms two L shaped members having a common arm, with the other two sections thereof being positionedsubstantially at rightangles each"; to the other to form a substantially L shaped arrangement. Fastened to the' housing 30 is an arm 55. Also fastened to the housing 30 is a pin 56 to which is joined a flexible member 51 which in turn is joined to a take-up spring arrangement partially illustrated at 58.

The action of the device is as follows. The transparent member Hi is always maintained in a fixed position, and the entire arrangement is mounted within a substantially light-tight housing. It will be apparent, therefore, that there are no moving parts to the outer portion of the machine which may be struck or interfered with in any fashion during operation of the machine. Since the member I0 is a semi-cylinder, the material tobe scanned may be merely placed over the semi-cylinder and a coverdrawn over it,.

and thus there is complete accessibility in either placing or removing material to be scanned from the device. In this illustration the scanning takes place along a line which travels-from right to left in the drawings. If it be assumed that 'the machine is at the starting position and operation' is desired, the button on the leverarm '42 is pushed downwardly. This causes the opposite end of the lever arm 40 to move upwardly and the lever armMl has joined to the end thereof a spring 38 which is maintained in compression. This means that when'the am All moves upwardly past the center point the spring 38'will force the portion of lever arm 35 to which it is Positioned in I nut 33 into engagement with the lead screw 21.

Since it has been indicated hereinbefore that the driving element and the scansion means and the lpre-amplifier all are mounted on a housing or scanning unit of the two scanning units which are displaced 180 with respect to each other,

. Y a plained hereinbefore to remove the half nut 33 from its engagement with the lead screw 21 and the support member is pulled back to a positionwhere scanning can start again; It is entirely as it passes adjacent the semi-cylindrical mem-' her In. The dual scanning units will be illustrated more clearly hereinafter in Fig. 4, and accordingly there will be stated at this point that the bottom portion of the machine has contained therein a non-reflecting, light absorbing member so that while one portion of the scanning unit is traversing this particular portion of the machine, no signals will be developed in the'photoelectric cell. As a result thereof, a commutating arrangement is avoided, and the advantages of a' dual scanning arrangement are provided. As the housing 30 moves along due to the engagement of lead screw 2'! with the half nut 33, it

feasible, however, to make the device completely automatic. A lever arm might be arranged to act with a member such as the member 55 on the support or housing 30 so that when the spring member pulls the support back to its initial position, the lever arm could be actuated to move the half nut arrangement into engagement with the lead screw 21, and again scanning would take place and the cycle would be repeated. This might be accomplished, for'in'stance, by having a slightly tilted member to push gradually downwardly against a lever arm joined directly to the shaft 34. On the other hand, one contact of a switch arrangement could be mounted on any of the traveling members supported by the support 30, and the other contact mounted at an appropriate place toclose an electrical circuit armature of a solenoid, this armature acting to will gradually reach a position where arm 55 willcome into contact with a portion of lever arm 50, as illustrated. When this is done, this lever arm will be rotated around the pivot 5| and the L shaped portion of the arm co-operating with lever 40 will be forced upwardly, thus turning lever arm 49 about its pivot point 4| so that the end thereof adjoining spring 38 will be forced downwardly. When thisis done the arm 40 will pass the center or neutral position of, the spring 38, and when it does the portion'of the lever arm joined to the spring 38 will be forced upwardly sharply. This means that the shaft 34 will be rotated and the half nut 33 will-be removed from engagement with the lead screw 21.

When the half nut 33 is removed from engageby the output light reflected from the object un-i dergoing scansion. Since such preamplifiers per push or pull the half nut arrangement into engagement with the lead screw 21. This might be done in, other ways,- but the two examples given are illustrative.

Referring to Fig 2, there is shown a portion of the support member 30 which illustrates the mounting of some parts thereof. A cross-sectional view of the container for the whole apparatus is shown' to illustrate the general working arrangement. Here the shaft l3 ends in a bearing in a gear box housing 60 and the motor 22 is mounted under the base 6| of the support member 30 by means of an appropriate bracket arrangese are well known, and since Well known forms may be used, it is entirely within the skill of persons practiced in the art to which this invention 1 belongs to construct and use and correctly connect such pre-amplifying. arrangements.

ment 62. The shaft'24 which ends in a worm 25 co-acting with the gear 26 fastened to thelead screw is illustrated, and bearing means 63 are illustrated as joined to the base plate 6| of the housing 30 for supporting the lead screw 21. It 1 will be noted that the base plate 6| has a sliding bearing arrangement 64 which fits around a guide rod 65, theguide rod being fastened at either end of the cabinet, or at other appropriate positions for the sake of supporting. the traveling housing 30.. Again, one side of the base plate 6| is cut in the form of a keyway 66 which fits onto a bracket member 61 and slides along the bracket, the bracket acting as a guide and supportrod. In

this instance, the guide is fastened to the wall 68 of the container. The semi-cylindrical trans? parent member is illustrated, as well as the member l2 containing the dual scanning arrangement and the pre-amplifi'er. Again, it should be noted thatin actual practice the pre-amplifler is not contained in the member I2, but is fastened onto the base plate 6|.

Referring to Fig. 3, there is shown a partial view of the apparatus that would be shown on a cutting plane transverse to the cabinet. In this to which this invention belongs to provide bea:

view the shaft I3 is shown, as well as the member 12. The path of rotation and the general direction of rotation has been indicated by the dashed and dotted circle 14. The edges of the transparent seml-cylindrical member in this case .are held between the edge 'I6 of the cabinet of the device and the bracket 11, so that this member does not move at all. The cover which allows accessibility to the semi-cylinder, and also holds the material in intimate contact with the semi-cylinder, is illustrated, and some parts are shown in detail. For instance, the outer sectionof the cover is formed of two sections 18 and E9, the two being 1 Joined by an elongated hinge 80. Also joined to 1 the cover is a resilient member 8| which is adapted to fit in intimate contact with the top of the semi-cylinder, and this member fits around a 1 rod- 82 and is held by one end of a spring member '83, the other of which is connected to the top at the position 84. It will be seen, therefore, that the further down that the cover is pulled, the more tensionis placed onthe member 8| by the action of the spring 83, and so the material which contains the intelligence to be transmitted is held in intimate contact with the top or the transparent semi-cylinder. This is a distinct advantage,

since no matter how thick the material may be,

the face thereof is always the same distance from the optical systems in the dual scaning elements, and hence focus is maintained at all times.

The subject matter of this particular arrangement forms the basis of another patent application, Serial No. 450,855, filed July 14, 1942, and

accordinglyjs not claimed in the present case.

Referring to Fig. 4, there is shown a partial view of the apparatus with the dual scanning arrangement illustrated. The shaft I3 .joins the housing l2 which contains therein a single source of light 92, and there is positioned so as to embrace this source of light two reflecting members What I claim is: 1. A scanning apparatus for developing electrical signals from a record surface representative of the optical values of said surface, comprising a plurality of scanning elements, each for developing electrical signals, means for supporting said record surface in a position to be scanned, said latter means comprising at least a portion of a substantially cylindrical member, a light absorbing member positioned diametrically opposite the record surface supporting means, means for rotating said scanning elements about the axis of placed apart from each other about the axis of rotation, and wherein each scanning element 95, each of-which has an aperture therein identi- Y fied by the numeral 96. At each extremity of the housing I2 is a lens holder arrangement 94 containing the lens 93 for directing light from the.

source onto the object to be scanned which is identified by the numeral ll, the object bein placed about the periphery of the 180 drum 10. Light from the object undergoing scansion will be reflected by means of reflectors 9 0 and 9| to the mirror arrangements consisting of the two elements 95, and from the mirror 95 onto the photoelectric cell 99, the latter being connected so as to feed its output energy into a well known form of pre-amplifying apparatus which is schematically represented at I00. The lower part of the apparatus has contained therein a non-reflecting material which allows one of the scanning units to direct light onto the object to be scanned and receive light therefrom in accordance with the optical values along the elemental sections thereof, while simultaneously the other scanning unit is positioned adjacent the light absorbing material 'so that no reflection takes place from the latter material, and the unit which is adjacent the light absorbing material at any time will be brought into a scanning relationship with the member In by the rotation of the shaft I3. Ac-

cordingly, nocommutating means are necessary for the photoelectric cell, and in addition a single source of light has been provided for use with both ends of the dual scanning head. The figure brings out the fact that there is no reflection back through the aperture 98 when the scanning head is in the position illustrated.

The means for and method of centering the scanning elements relatively to the transparent plastic member ID constitute very important means in conjunction with this apparatus, and

' accordingly are more particularly shown and disclosed in an additional patent application, Serial No. 450,856, filed July 14,1942,

' wherein a single motor means is provided for scans alternatelines of the record surface.

3. Apparatus in accordance with claim 1, wherein a single motor means is provided for rotating thescanni g elements and for traversing the scanning leinents longitudinally relative to the object o be scanned.

4. Apparat in accordance with claim 1,

rotating the scanning elements and for traversing the scanning elements longitudinally relative to the object to be scanned, and wherein said single motor means is mounted on a housing supporting the scanning elements and pre-amplifier means mounted on the same housing.

5. A scanning apparatus for developing signals from a record surface which are indicative of the optical values of said record surface, comprising means for supporting said record surface, said latter means comprising at least a partial cylinder, a plurality of rotatable scanning means spaced apart from each other and positioned adjacent said supporting member, means for retating said scanning means about the axis of symmetry of said record support means, a nonreflecting surface positioned diametrically opposite said record support means, and means for traversing said scanning means longitudinally the spirit and scope thereof, and accordingly I claim to be entitled to all such departures as fall fairly within the spirit and scope of the invention as defined in the hereinafter appended claims.

with respect to said record supporting member whereby the record surface is linearly scanned by each of the scanning means by means of the sequential scanning of the surface by the scanning means during their longitudinal traversal of the surface. 1

6. Apparatus in accordance with claim 5,

wherein said plurality of scanning means comprises a pair of individual scanning members spaced apart from each other.

7. A scanning apparatus for developing signals from a record surface which are indicative of the optical values of said record surface, comprising means for supporting said record surface, said latter means comprising a substantially semicylindrical transparent member, means for holding the record surface in intimate contact with said semi-cylindrical member, a pair of rotatable scanning elements adapted to be rotated simultaneously, and spaced apart from each other, means for rotating said scanning elements about the longitudinal axis of the semi-cylindrical transparent member whereby each of the scanning elements scans a linear section cf-the record 8. Apparatus in accordance with claim 7,

wherein said rotatable pair of individual scanning elements are spaced apart from each other substantially 180 relative to their axis of rotation.

9. A scanning apparatus for developing signals from a record surface which are indicative of the optical values of said record surface, comprising means for supporting said record surface, said latter means comprising a substantially semicylindrical transparent member, a pair of rotatable scanning elements positioned adjacent said transparent support member, housing' means, means for rotating said rotating scanning ele- -ments about the longitudinal axis 01 said semicylindrical transparent member, lead screw means, means for driving said meansfor rotating said scanning elements and said lead screw means simultaneously, said means for rotating said scanning elements, said lead screw means, and

tudinally traverse the transparent support member while rotating adjacent thereto, whereby at least a. portion of said record surface is linearly scanned sequentially by said rotating scanning elements, and light absorbing surfaces to substantially preclude the development of signals from thescanning elements except during the intervals that they are opposite the semi-cylindrical support means.

10. Apparatus in accordancewith claim 9,

wherein said means for engaging said lead screw I means comprises a threaded member and -wherein there is provided in addition means for actuating said'threaded member to bring it into or out of engagement with said lead screw means.

11. Apparatus in accordance with claim 9, wherein means are provided for slidably supporting said housing, whereby the housing may cause the longitudinal traversal of the transparent support member by said rotating scanning elements. 12. Apparatus in accordance with claim 9, wherein said means for engaging said lead screw means comprises a threaded member and wherein there isprovided in addition means for actuating. said threaded member to bring it into engagement with said lead screw means, means for automatically disengaging said threaded member from said lead screw means, means for returning said housing member to an initial scanning position, and means for slidably supporting said housing. 1

CHARLES J. YOUNG.

Images