US2964742A

US2964742A - Decimal storage and display unit

Info

Publication number: US2964742A
Application number: US630863A
Authority: US
Inventors: Godet Sidney
Original assignee: Reeves Instrument Corp
Current assignee: Reeves Instrument Corp
Priority date: 1956-12-27
Filing date: 1956-12-27
Publication date: 1960-12-13
Anticipated expiration: 1977-12-13

Description

Dec. 13, 1960 s. GODET DECIMAL STORAGE AND DISPLAY UNIT 3 Sheets-Sheet 1 Filed Dec. 27, 1956 IN V EN TOR. S/DNEY Gops'r @6 4 flTTORNEYS Dec. 13, 1960 s. GQDET 2,9 4,742

DECIMAL STQRAGE AND DISPLAY UNIT Filed Dec.- 27, 1956 3 Sheets-Sheet 2 INVENTOR. SIDNEY GQDET Dec. 13, 1960 s. GODET 2,964,742

DECIMAL STORAGEYAND DISPLAY UNIT Filed Dec. 27, 1956 s Sheets-Sheet 3 T1r:1-1l.

EN'PG/ZED (1) f/vEPG/ZED O was 12:13

ENEPG/ZED INVENTOR. S/DA/EY @0251 BY @AW @614 Z #W United States Patent DECIMAL STORAGE ANDDISPLAY UNIT Sidney Godet, Great Neck, N.Y., assignor to Reeves Instrument Corporation, New York, N.Y., a corporation of New York Filed Dec. 27, 1956, Ser. No. 630,863

13 Claims. (Cl. 340--324) This invention relates to storage and display devices and more specifically to a novel and improved device responsive to a coded decimal or binary system for visually displaying reference characters such as Arabic numerals.

In addition to displaying a numeral set up on the input lines, the device will retain the information after removal of power from the input lines and will provide output signals corresponding to the stored information in binary form. Through the use of a number of these devices simultaneous multi-digit numbers can be displayed.

One object of the invention is the provision of an improved display device responsive to a coded decimal system for visually reproducing digits 0 through 9 and at the same time storing information pertaining to the digit being displayed for the control of other apparatus.

Another object of the invention is to provide a decimal storage and display device that is characterized by its simplicity, dependability and relatively low cost. Through an improved arrangement and combination of elements the number of moving parts are reduced to a minimum and the device will respond substantially instantaneously to a given signal or set of signals representing or denoting the digit to be displayed.

The above and other objects of the invention will become more apparent from the following description and accompanying drawings forming part of this application.

In the drawings:

Fig. l is a plan view in section along the line 11 of Fig. 2 of a display device embodying the present invention;

Fig. 2 is a side elevational view of the apparatus shown in Fig. 1 in section along the line 2-2 thereof;

Fig. 3 is a cross-sectional view of the apparatus shown in Fig. 1 taken along the line 33 thereof;

Fig. 4 is a bottom view of the portion of the apparatus shown in Fig. 3;

Fig. 5 is a cross-sectional view of the apparatus shown in Fig. 1 taken along the line 55 thereof;

Fig. 6 is a perspective view of the rotary solenoid armature and rotary mirror shown in the cross-sectional view of Fig. 5;

Fig. 7 is a diagrammatic view of the solenoid stator shown in Fig. 5 with the wiring connections thereto;

Figs. 8, 8a, 9, and 9a are diagrammatic illustrations of portions of the rotary solenoid illustrating the organization of elements and operation thereof;

Fig. 10 is a circuit diagram illustrating the operation of the device shown in Figs. 1 through 9a, inclusive; and

Fig. 11 is a chart illustrating one binary system and the manner in which the apparatus illustrated is operated to attain the desired results.

Broadly, the invention provides an improved device embodying an optical system having four moving elements arranged and coordinated to provide for the optical display of ten digits. It is actuated by coded data in the form of four voltages that are either present or absent in four separate circuits. Each of the circuits controls the operation of one of the moving elements so that 2,964,742 Patented Dec. 13, 1960 selected operation of the moving elements will function to project a visible reproduction or image of the selected number or digit.

In the illustrated embodiment of the invention, the four individual solenoid units are associated with the

numbers

1, 2, 4, and 8, combinations of which can be used to reproduce all of the digits 1 through 9. For instance, the digit 3 can be obtained by energizing the solenoid units associated with the

numbers

1 and 2. The digit 7 can be produced by energizing the solenoid units associated with the

numbers

1, 2, and 4. 0 is produced when all the solenoid units are deenergized. It is to be understood that while the foregoing binary system was selected for use in connection with the illustrated embodiment of the invention, any other suitable system may be used.

The storage feature on this invention is preferably obtained by mechanically coupling electric switches with each of the four moving elements so that actuation of selected moving elements to reproduce a given digit will actuate the associated switches to store the binary information in any suitable and well-known manner. Through the utilization of an improved rotary solenoid forming the actuating means for the moving elements, a single clearing signal may be applied to all of the elements after display of a selected digit and prior to the transmission of a new set of signals for the display of a new digit or set of digits.

Referring to the drawings, there is illustrated a single display unit which includes a housing 10 having substantially parallel side walls 11 and 12 and contoured upper and lower surfaces, the latter functioning not only to enclose the optical elements within the housing, but also as part of the optical system as will be described.

The four moving elements of the optical system for the selection of the digit or character to be displayed by the apparatus are generally denoted by the letters A through D, inclusive. The element A includes a two position rotary solenoid 13 mounted on the outside of the side wall 11 for the operation of a mirror 14 disposed within the housing. The element B includes a two position rotary solenoid 15 and an associated mirror 16 disposed within the housing as in the case of the mirror 14. The axis of rotation of the mirrors 14 and 16 are disposed transversely of the housing and in this embodiment of the invention are in a horizontal plane. The element C which is similar to elements A and B, includes a two position rotary solenoid l7 and a mirror 18 coupled thereto. The mirror 18 rotates about an axis in a vertical plane and is positioned adjacent a projector lens 19 mounted in the right-hand end of the housing 10. The fourth moving element D also includes a two position rotary solenoid 20 which is similar to the solenoids used in connection with the other elements and is disposed at one end of a rotatable turnstile-like member 21 having four elongated opaque panels 22 spaced at intervals about and extending from a central supporting shaft 23. The panels 22 disposed in one plane carry the

numerals

1, 5, 9, 0, 4, 8 as illustrated in Fig. 2, while the panel 22 disposed in a plane perpendicular to the first panels, carry the

numerals

3, 7, 2, and 6. The numerals or other characters on the elongated panels 22 may be formed of translucent or transparent material or they may be formed by openings in the panels 22 to permit the passage of light therethrough. In the present embodiment of the invention, the numerals or digits on the turnstile 21 are illustrated as being illuminated by a suitable light source such as the lamps 24 disposed at the lefth-and portion of the housing 10, as shown in Figs. 1 and 2. However, it will be understood that any suitable procedure or struc ture may be used for illuminating the characters to be displayed.

, In addition to the elements of the optical system referred to above, the upper wall of the housing includes an inclined section 25 having a reflecting surface on the inner side thereof. The top of the housing further includes a horizontal surface 26 for mounting the solenoid 20 and providing a bearing'surface for the turnstile 21 and a lower horizontal portion 27 on which the solenoid 17 driving the mirror 18 is mounted. The lower wall of the housing includes an inclined portion 28 having a reflector surface on the inside thereof. The lower end of the inclined portion 28 joins with a horizontal portion 29 which provides the bottom bearing surface for the turnstile member. The upper end of the inclined wall part 28 terminates in a substantially vertical portion 30 which joins with a horizontal portion 31 that provides the lower bearing for the mirror 18. A vertically disposed end piece 32 extends between the

horizontal portions

27 and 31 at the right-hand end of the housing and carries a suitable objective lens 19.

Two additional reflecting surfaces denoted by the numerals 33 and 34 are formed on the inner surface of the right-hand ends of the side walls 11 and 12 as may be observed in Fig. 1. The ends of these side walls are bent inwardly at angles of approximately 45 and terminate short of the objective lens 19 so that they will not block the transmission of light through the lens. Another set of reflecting surfaces denoted by the

numerals

35 and 36 are positioned approximately midway between the turnstile member 21 and the objective lens 19. The reflecting

surfaces

35 and 36 are each aligned with one of the numerals at the center of the panel 22 and may be formed by tabs partially cut from the side walls 11 and 12 and bent inwardly to form incline surfaces at angles of 45 with respect to the vertical axis of the turnstile 22.

As will be seen best from Fig. 2, light rays emanating from the numerals on the turnstile panels are deflected and directed toward the reflecting surfaces 33 and 34 adjacent the lens by means of the reflecting surfaces on the

inclined walls

25 and 28, and the

tabs

35 and 36 in conjunction with the mirrors 14 and 16. As will now be explained, the position of the mirrors 14 and 16 will determine the particular horizontal pair of numerals which will be projected to the reflecting surfaces 33 and 34. In general, the reflecting surfaces are inclined at approximately 45 to the light rays striking them and thus the reflected light rays will be deflected at approximately 90 from the incident light rays.

Specifically, the light rays from the top pair of numerals (three and two or one and zero) will first strike the reflecting surface of the inclined wall 25 and be deflected downward to the mirror 14. The mirror 14 deflects the light rays toward a lower point on the reflecting surface of the inclined wall 25 which in turn deflects the light rays downward to the mirror 16 and the mirror 16 will deflect the light rays toward the reflecting surfaces 34 and 33.

If the mirror 14 is shifted 90 (to the dot and dash line position), light from the top pair of numerals is cut oif at this point and light rays from the middle pair of numerals (seven and six or five and four) will strike the reflective surfaces on the

inclined tabs

35 and 36 and be deflected upwardly to the reflective surface of the mirror 14. The mirror 14 again deflects these light rays toward the reflecting surface on the inclined wall 25 which in turn deflects the light rays to the mirror 16. The mirror 16 then deflects the light rays to the reflecting surfaces 33 and 34 as it did previously. Hence, the shift from the top pair of numerals to the middle pair of numerals is controlled by the position of the mirror 14.

When the reflecting surface mirror 16 is shifted 90 (to the dot and dash line position), the light rays from the top and middle rows of numerals are cut off and the light rays from the lower pair of numerals (nine and eight) will be directed toward the reflecting surfaces 33 and 34. In this case, the light rays from the lower pair of numerals strike the reflecting surface on the inclined wall 28 of the housing and are deflected upwardly toward the mirror 16 and thence to the reflecting surfaces 33 and 34. V

As will be seen best from Fig. 1, the position of the mirror 18 controls the projection of either the left or right hand numeral of the pair of numerals to the lens 19. For example, when light rays from the reflecting surface 34 strike the reflecting surface of the mirror 18, the rays will be deflected by the mirror toward the lens while light rays from the other reflective surface 33 are cut off. When the reflective surface of the mirror 18 is shifted (to the dot and dash line position), the light rays from the reflecting surface 33 are deflected by the mirror toward the lens 19 and the light rays from the reflecting surface 34 are cut 011.

From the above it will be observed that by positioning of the turnstile 21 and the three reflecting

mirrors

14, 16, and 18, any one of the ten numerals may be selected for projection to the objective lens 19. If desired, a series of numerals can be projected simultaneously by the use of a number of the devices positioned side by side.

The positions of the turnstile 21 and the

mirrors

14, 16, and 18 are controlled by the two

position rotary solenoids

13, 15, 17, and 20. The rotary solenoids are all identical in structure and therefore only one of the solenoids need be described in detail. As shown in Fig. 5, the operable elements of the solenoid 17 are contained within an outer generally circular housing 37 that is preferably of a magnetic material. A pair of

armatures

38 and 39 are fixedly secured to a central shaft 40 rotatably mounted within the housing 37 and extending therefrom to carry the operable element such as the mirror 18 or in the cases of the other solenoids the mirrors 14 and 16 and the turnstile member 21.

The

armatures

38 and 39 are arranged in spaced relationship and are preferably angularly displaced with relation to each other. In the illustrated embodiment of the invention, the armatures are displaced by an angle of about 30 degrees (see Fig. 6). The field structures for the

armatures

38 and 39 comprise a pair of

pole pieces

41 and 42 associated with the armature 39 and a second pair of

pole pieces

43 and 44 associated with the armature 38. The arrangement and disposition of the pole pieces 41 through 44 is shown more clearly in Fig. 7. The pole pieces in this embodiment of the invention have arcuate lengths of 90 degrees and are provided with coils or windings denoted by the numerals 41a to 44a, inclusive. The

pole pieces

41 and 42 comprise the stator for the armature 39 and are magnetically coupled to the casing 37 so that when the respective coils 41a and 42a are energized either in series or parallel, a magnetic field will be generated therebetween. The

pole pieces

43 and 44 comprising the stator for the armature 38 are offset from the

pole pieces

41 and 42 and also utilize the casing 37 as part of the magnetic circuit.

As will be shown, energization of the stator associated with one armature will function to rotate the shaft 40 in one direction while energization of the stator associated with the other armature will function to rotate the shaft 40 in the opposite direction. In order to insure precise movement of the shaft 40 through an angle of 90 degrees, a toggle spring assembly, generally denoted by the numeral 45, is utilized to cooperate with the solenoid to attain this end. The bottom view of the turnstile assembly, as shown in Fig. 4, will serve to illustrate the structure and operation of this toggle control. The bottom end of the shaft 23 of the turnstile 21 includes a pair of outwardly extending

arms

46 and 47. A tab or post 48 is secured to and extends from the bottom part 29 of the casing 10 and is disposed at a point in alignment with the

arms

46 and 47 when the turnstile is positioned at a point midway of its throw and at the side of the arm 47. A spring 49 is connected between the arm 46 and the post or stud 48 so that movement of the arm 46 from a position on one side of center through the center position will enable the spring to cause .the armtocontinue its movement to its other end position. By reason of this toggle action,,the driving solenoid need only effect rotation slightly past the center position when going in either direction, whereupon the action of the spring 49 will complete the rotation. Rotation of precisely 90 degrees is controlled by a pair of

stops

50 and 51 which cooperate with the arm 47.

In order to store information fed to the driving solenoids or for the purpose of control of other equipment, each arm 47 is provided with a short extension 47 for actuating a suitable micro switch 52. With this arrangement, when thearm 47 is in one position, the switch 52 is closed while in the other position of the arm 47 the switch is open. Thus, either momentary or continuous energization of certain of the solenoids to display a given character or digit will function to actuate the associated switches. By connecting each of the four switches to suitable apparatus (not shown), information indicating the numeral represented by the information fed to the display device may be transmitted to such apparatus.

The relay casings 37 which include the stator structure may be secured to the wall of the casing 10 in any suitable manner as, for instance, by tabs 37', as shown in Fig. 5. The shafts 40 for the several mirrors and shaft 23 for the turnstile are preferably supported by the walls of the casing, although separate bearing structures may be provided for this purpose if desired.

In order to illustrate more clearly the operation of the rotary solenoids, the two positions of eachof the

armatures

38 and 39 relative totheir associated pole pieces are shown in Figs. 8, 8a, 9, and 90.

As was pointed out above, each of the pole pieces 41 to 44 comprise 90 degree segments with reference to the center of rotation of the

armatures

38 and 39. In addition, the arcuate length of the pole faces 38 and 39 of the armatures 38 andf39 are approximately 60 degrees as measured from the center of rotation. In the counterclockwise position of the armature 39, as shown in Fig. 8, it will be observed that the leading edges a and c of the faces 39 of the armature 39 are aligned with the

edges

41 and 42 of the

pole pieces

41 and 42 forming part of the stator. With the armature in this position it is to be understood that the toggle spring 49 has moved the arm 47 against one of the

stops

50, 51 as previously described. In the corresponding position of the armature 38, as shown in Fig. 9, it will be observed that the trailing edges b and d of the pole faces 38 of the armature 38 are in line with the edges 43' and 44 of the

stator pole pieces

43 and 44. Since the trailing edges 1) and d of the armature 39 are spaced 30 degrees from the edges 41" and 42" of the

poles

41 and 42, the armature 39 will move in a clockwise direction when the field coils-41a and 42a associated with the

pole pieces

41 and 42 are energized momentarily. Positive motion is imparted to the armature 39 by the stator until the points b and d are in alignment with the

edges

41 and 42 of the poles 41- and 42. Since the arcuate length of the armature pole faces is 60 degrees, the positive clockwise movement imparted to the armature will be approximately 60' degrees, at which time the magnetic effects of the

pole pieces

41 and 42 will no longer function to rotate the armature 39. At this point the armature can be readily moved through the remaining angle of 30 degrees without moving the pole faces 39' from beneath the

stator poles

41 and 42. The initial 60 degree clockwise motion imparted by the stator will function to move the arm 46 of the toggle assembly past a dead center position and the spring will carry the armature 39 from a position wherein the edges of the armature pole faces b and d are in alignment with the edges of the

stator poles

41 and 42 to the position shown in Fig. 8a wherein the edges of the armature poles a and c are in alignment with the edges 41" and 42" of the

poles

41 and 42.

During the displacement of the armature 39 in a clockwise direction as described in Figs. 8 and 8a, the armature 54 to 5 7 is the number or digit to be presented. If, for

33 will have been moved from the position shown in Fig. 9 to the position shown in Fig. 9a. The energization of the field coils 43a and 44a associated with the

stator poles

43 and 44 will function to move the armature 38 in a counterclockwise direction from the position shown in Fig. 9a. More specifically, energizing the

poles

43 and 44 will move the armature 38 in a counterclockwise direction through an angle of 60 degrees, at which point the toggle spring 49 will take over and move the armature to the position shown in Fig. 9. Thus, a relatively short electrical impulse applied to field coils for the respective stators will effect clockwise or counterclockwise motion of the shaft 40. In either case, the rotation of the shaft will be precisely degrees and the solenoids will function with either short electrical pulses or continuous signals.

The binary system for controlling the operation of the

solenoids

13, 15, 17, and 20 is illustrated in Figs. 10 and 11. The binary system selected for the operation of the display and storage device described above utilizes four individual circuits each of which represents some integral power of two.

Referring now to Fig. 10, the leads projecting from the top of each solenoid A through D, inclusive, are coupled with the stator that functions to move the solenoids in a clockwise direction as viewed in Fig. 10. The leads extending from the bottom of each solenoid are used to move them in a counterclockwise direction. One lead from the stators of each solenoid is connected to the ground terminal 53.. The remaining leads extending from the upper side of each solenoid are connected to the terminals 54 to 57, inclusive. The other lead extending from the bottom side of each solenoid is connected to the terminal 58 to which is applied a clearing signal for returning the system to a zero position. For convenience, the solenoids A through D, inclusive, in Fig. 10 have been illustrated diagrammatically along with their associated switches 52 actuated by varms 47 so that movement of a given solenoid will actuate a switch inorder to store the information applied to the system.

Specifically, the terminal 54 isassociated with the number 4 and application of energy between it and the ground terminal 53 functions to move the solenoid A (13) in a clockwise direction.- The signal applied to the. terminal 55 is associated 'with the number 8 and functions to move the solenoidB, (15) in a clockwise direction. Similarly, the signal applied to terminal 56 is associated with the numberl and functions to.move the solenoid C (17) in a clockwise direction. The signal applied to the terminal 57 is associated with the number 2 and functions to move the solenoid D 20) in a clockwise direction. With this arrangement, the sum of thenumbers represented by the voltages at one or more of the terminals instance, voltages representing the

numbers

1 and 2 are presented, the digit that will be displayed by the device will be number 3. If it is intended todisplay number 7, voltages will be applied to the terminals 54, S6, and 57 which represent the

numbers

1, 2, and 4 which total 7.

The chart in Fig. 11 illustrates the system utilized for attaining the display of any given numeral from zero through 9. For example, if all of the units A through D are deenergized (in their counterclockwise positions), the number that will be projected through the objective lens 19 will be zero. Momentarily energizing the unit C associated with the mirror 18 will produce the digit 1. If the unit D is energized and all other units are deenergized, the number indicated will be the numeral 2. If both units C and D are energized, the number indicated will be 3, etc. With the present embodiment of the invention it is possible to obtain the

numerals

8 and 9 with two different arrangements of signals inasmuch as it will.

be noted that once the mirror 16 is rotated to the clock-.

wise position shown in Fig. 2, movement of the mirror 14 in response to the operation of the rotary solenoid forming part of unit A will have no effect on the system. A similar situation applies to the blank spaces on the turnstile below the

numerals

6 and 7.

The arrangement described above will provide a dependable relatively low cost device that will respond to a suitable binary code to project images such as the numerals through 9, inclusive, and may also be used to store the information for use in controlling other apparatus if desired. By reason of the improved rotary solenoids, the system will respond to signals in the form of momentary pulses or continuous voltages. Similarly, the clearing signal applied to the terminal 58 may be either a continuous or momentary signal and will function to bring all of the units A through D to their counterclockwise or zero positions. Any unit being in the zero or counterclockwise position when the zero signal is applied will be unaffected by such clearing signal. It may also be noted that once a signal is applied to a unit or a number of units in order to move them in a clockwise direction, subsequent application of another signal to such unit will not affect its position. In certain cases it is not necessary to apply a clearing signal before presenting the code for the display of a different digit. For instance, if the numeral 1 is being displayed and the binary code calls for the presentation of the numeral 3 it would only be necessary to energize the unit D. However, for simplicity it may be desirable to clear the display device each time a new numeral or digit is to be presented.

In illustrating the invention, the switches 52 have been illustrated as single-pole, single-throw devices though it is understood that other types of switches may be employed for operation by the rotary solenoids A through D. Instead of operating electrical switches, the solenoids may, of course, be employed to operate other mechanical or electromechanical devices as may be desired.

It should be noted that the lengths of the several light paths from lens element 19 through the reflecting mirror system to each of the numerals on the turnstile panels 22 are identical. Thus, a focusing adjustment for lens 19 is unnecessary as the different numbers are projected by the display unit.

The numerals 0-9 in Figs. 2 and 3 have been shown, for convenience, as appearing right side up. These numerals, however, would be projected upside down upon a screen due to the optical inversion through lens 19. To project the numerals right side up, the display unit may be operated in an inverted position.

It will be understood that various modifications, alterations and changes may be made in the embodiment of the invention illustrated and described herein without departing from the scope of the invention as defined by the claims appended hereto.

I claim:

1. A display device comprising an objective lens, at least two groups of light emitting characters, electromechanical means for positioning said groups of characters to emit light in the direction of said lens, a plurality of fixed reflectors and movable reflectors interposed in the path of said emitted light and a plurality of electromechanical positioning devices each coupled to one of said movable reflectors for individually positioning each of the movable reflectors in predetermined positions for presenting light from individual characters to said lens while blocking light from the other of said characters, said electromechanical devices being responsive to coded sets of electric signals representing said characters.

2. A display device according to claim 1 wherein said electromechanical positioning devices coupled to each of the movable reflectors comprise a two position rotary solenoid, said solenoid being rotatable in opposite directions through an arc of predetermined magnitude.

3. A display device according to claim 1 wherein said groups of characters are carried by panels disposed at right angles one to the other and movable through an angle of approximately 90 to position said groups individuallyw for the projection of light from selected characters to said lens.

4. A display device responsive to coded binary electric signals for optically displaying digits represented by said signals comprising a plurality of light emitting characters in the form of digits to be displayed, a lens spaced from said light emitting characters, fixed reflectors disposed between said characters and said lens, at least three rotatable reflectors each individually movable from one position to another, and electromechanical positioning devices coupled to each of said rotatable reflectors, said electromechanical positioning devices being responsive to said signals for positioning said rotatable reflectors in positions where the light from a character represented by a coded signal is directed to said lens while light from other characters is blcckedfrom the lens.

5. A display device according to claim 4 wherein said characters including the numbers 0 through 9 are carried on two panels disposed at right angles one to the other in the form of a rotatable turnstile and said device further includes electromechanical means for rotating said turnstile in opposite directions in response to said coded signals, and said code includes at least four individual signals each applied to one of said electromechanical devices and to said electromechanical means representing the

digits

1, 2, 4, and 8 and a clearing signal representing zero.

6. A display device according to claim 4 wherein said electromechanical positioning devices each comprises a rotary solenoid having a driven shaft and toggle spring means coupled to the shaft, said solenoid being movable through a predetermined angle first in one direction and then the other in response to electrical signals applied thereto and the cooperating action of said toggle spring means.

7. A display device according to claim 4 including switch means responsive to said electromechanical means for storing said coded signals.

8. A display device for optically displaying characters in response to an applied electric signal comprising in combination, an opaque panel member having a plurality of transparent openings therethrough shaped according to the characters to be displayed, a light source situated adjacent said panel member for passing light rays through each of the openings in said panel member, fixed mirrors located in the paths of each of the groups of light rays passing through the openings in said panel member, said fixed mirrors being angularly inclined with respect to the light rays for reflecting the light rays passing through each of the openings in said panel member, a rotatable 2- position mirror situated in the reflected light paths of at least two of the characters to be displayed and being angularly inclined with respect to the reflected light rays, electromechanical means coupled to said rotatable mirror and responsive to an applied signal for varying the angular position of said rotatable mirror from a first angular position to a second angular position, said rotatable 2- position mirror reflecting light rays from one of the characters to be displayed when disposed in said first angular position and reflecting another of said characters when disposed in said second angular position, and lens means situated in the path of the light rays reflected from said rotatable 2 position mirror for projecting said latter reflected light rays.

9. A display device for optically projecting a symbol selected from a plurality of illuminated symbols arranged in rows and columns comprising a group of fixed row reflectors, each fixed row reflector being located directly in the path of light rays from a corresponding row of said illuminated symbols, a group of fixed column reflectors, each fixed column reflector being located directly in the path of light rays from a corresponding column of said illuminated symbols, said fixed row and column reflectors being angularly inclined -with respect to said light rays, a group of first movable reflectors, one of said first movable reflectors being located between pairs of said fixed row and column reflectors and adapted for selectively reflecting light from one or the other of said pairs of fixed row and column reflectors, a group of angularly inclined secondary reflectors including at least one secondary fixed reflector and at least one secondary movable reflector, each of said secondary fixed reflectors being located directly in the path of light from a movable reflector and each of said secondary movable reflectors being located between each of said fixed reflectors not having a first movable reflector receiving light directly therefrom, and lens means adapted to rece.ving light transmitted by said reflectors from any of said illuminated symbols.

10. A selective display device for optically projecting a symbol selected from a group of illuminated symbols arranged in rows and columns, comprising a group of fixed row reflectors, each of said fixed row reflectors being located in the path of light rays emanating from a corresponding row of said illuminated symbols, said fixed row reflectors being angularly inclined with respect to said light rays, a pair of angularly inclined fixed column reflectors, first and second movable reflectors, said first movable reflector being situated between a pair of fixed row reflectors, said second movable reflector being situated between said pair of fixed column reflectors, said first and second movable reflectors being adapted for selectively reflecting light from one or the other of said pair of fixed row reflectors and said pair of fixed column reflectors respectively, an angularly inclined secondary fixed reflector situated in the path of light reflected from said first movable reflector, a secondary movable reflector situated between said secondary fixed reflector and one of said fixed row reflectors, said fixed column reflectors being situated in the path of light reflected from said secondary movable reflector, and lens means situated in the path of light reflected from said second movable reflector for projecting one of said selected symbols.

11. A display device for selecting and optically projecting one of a plurality of symbols in response to a coded input signal comprising housing means, panel means mounted within said housing means, said panel means including a plurality of illuminated symbols, lens means spaced from said panel means, a plurality of fixed reflectors located within said housing means between said panel means and said lens means, a plurality of individually movable reflectors located within said housing means between said panel means and said lens means, and a plurality of electromechanical positioning devices responsive to said coded input signal, each of said electromechanical positioning devices being coupled to one of said movable reflectors, said positioning devices positioning said movable reflectors to permit light rays from only the selected symbol to reach said lens means.

12. A display device as defined in claim 11 wherein the panel means is rotatable and which further comprises means for positioning said panel means in accordance with said coded input signal.

13. A display device as defined in claim 11 wherein said movable reflectors are rotatable and said plurality of positioning devices individually position each of said reflectors to either a first or a second angular position in accordance with said coded input signal.

References Cited in the file of this patent UNITED STATES PATENTS 1,893,158 Chireix Jan. 3, 1933 2,646,732 Ofleman July 28, 1953 2,738,450 Matthews Mar. 13, 1956 2,767,628 Higonnet Oct. 23, 1956 2,779,016 Shell Jan. 22, 1957 2,784,397 Branson Mar. 5, 1957 2,800,614 Thornbery July 23, 1957 2,803,178 Lotz Aug. 20, 1957