US 3822493 A
A display apparatus for displaying a plurality of items on a curtain wherein the items are back-lighted by a light source and the curtain further contains coded position information associated with each item which is also backlighted by the same light source so that photo-sensitive devices may sense the position of the curtain.
Description (OCR text may contain errors)
United States Patent 1191 Maley 3,822,493 July 9, 1974 DISPLAY APPARATUS 3,151.409 10/1964 Boganrtwt... Inventor: William B. y, g Conn 3,386,088 5/]968 Johnston..............  Assignee: Techlite, lnc., Milford, Conn.
[ 22] Filed:
Primary ExaminerJoseph S. Reich Assistant Examiner-J. H. Wolfe Feb. 4, 1972 Attorney, Agent, or FirmDeLio and Montgomery  Appl. No.: 223,473
 ABSTRACT A display apparatus for displaying a plurality of items on a curtain wherein the items are back-lighted by a light source and the curtain further contains coded position information associated with each item which is also backlighted by the same light source so that photo-sensitive devices may sense the position of the curtain.
 US; 40/31, 340/324 R ] Int. G09f 11/28  Field of Scarch........... 40/52, 53, 53 A, 31, 32; 353/25, 26; 340/324 B, 278 MW, 324 S  References Cited UNITED STATES PATENTS 7/1938 3: re and BEE-22:.
PATENTED JUL 91974 SHEET 1 BF 2 K nw SHEET 2 0F 2 KQEMEQEQU hag PAIENIEDJUL 91w w Hm.
This invention relates to display signs and more particularly relates to display signs and positioning controls therefor of thetype adapted to be mounted to a public vehicle to display the destinations thereof.
In vehicles used for public transportation, such as rail cars, a destination sign is utilized to indicate to boarding passengers the destination and/or route of the train. Upon reaching one destination, signs on all the cars must be changed to show the next destination. In more modern rail transit vehicles this is accomplished by providing a plurality of possible destinations on a curtain and the curtain is driven to a commanded position on all cars from a central control.
One way that this may be accomplished is by placing on the curtain a code and a source of illumination therebehind and then reading through the use of photocells and associated logic circuitry agiven destination on the curtain as it passes the photocells. In these known devices, two sources of illumination have been required, one for the code reading and the other to backlight the destination intelligence on the curtain. This type of arrangement is such that the overall housing for the destination sign and the logic controls therefor become rather bulky. In addition, most of the known destination signs of the type described are in the form of an endless belt movable in only-one direction.
The present invention provides a new and improved destination display containing means for automatically positioning a given display in a window and backlighb ing the same while illuminating both the destination in telligence and the position with a single illuminating or light source, and moreover also displaying destination inside the vehicle as well as outside thereof. The invention further comprises a new and improved positioning bidirectional curtain positioning control.
Briefly stated, the invention in one form thereof comprises a housing member which is adapted to be received in a receptacle provided therefor in a transit vehicle, and which utilizes a generally opaque curtain with translucent destination and coding intelligence thereon. The curtain has the ends thereof mounted to different rollers which may be alternatively driven dependent upon the direction of location desired. The drive rollers and idler rollers about which the curtain passes are so arranged that a portion of the curtain defines a U-shape and a single illuminating source is dis posed within the bight of the arms of the U. The intelligence on the curtain is so positioned that photocells carried on the housing sense the position code while at the same time the destination intelligence is displayed through a viewing window. The invention further comprises new and improved logic means for comparing.
position intelligence read from the curtain with a commanded position and driving the curtain to display the desired destination.
An object of this invention is to provide a new and improved display sign and operating mechanism therefor.
Another object of this invention is to provide apparatus of the type described having a new and improved construction which permits a single light source to both illuminate the destination display and a coding to be.
read by photo-sensitive elements.
A further object of this invention is to provide a device of the type described having new and improved simplified drive means for driving a display curtain in either direction.
The features of the invention which are believed to, be novel are particularly set forth and distinctly FIG. 4 is a view of a section of a display curtain utilized in the invention;
FIG. 5 is a diagram partly in block and partly inschematic form showing the curtain drive and positioning logic therefor;
FIG. 6 is a diagram of an end view oiian alternate are rangement using an endless curtain; and
FIG. 7 is a diagram of an. end view of another" an. rangement of the invention.
Apparatus embodying the invention generally com.- prises a frame member 10 havingtop-and bottom members l1 and 12, respectively, together with side members 13. A side of a vehicle 1 5 with a window Ititherein may provide the front cover for theapparatus. The rear cover has been removed for simplicity and cIarit-yof il lustration. Flange members 17 and 18: maybe integral with side members 13 and have handles W'at'hereoni to facilitate placement and removalof the apparatus: for servicing or repair.
' Supported from the frame members. isra circuitboarcl I 20 which mounts a plurality of photo-sensitive elements such as photocells 21 in a givensspaced relatioir and adapted to read coded information fromra curtain 22. Curtain 22 has one end thereof afiixedfto arol let 23 and the other end thereof affixed toa roller 24?...
In FIG. 3, the size of the destination display on; curl tain 22 is indicated by the dimension W. The dimensions V represents the area viewed by the photocells.
The rollers 23 and 24 have collars 25athereon adjacent shaft ends of reduced diameter. The shaftends'26; are rotatably received in mounting brackets. 21' andJ' ZSQ. respectively, on one side frame. The other endstof rollers 23 and 24 are attached to one element of clutches. 29 and 30, respectively. The clutches. and30tarer carried on gears 31 and 32 on shafts 33'sandfl34,.respec tively, rotatably mounted in a side frame IBLCurtaihs guides 35 and 36 extend between side. frame: 113, and! together with rollers 23 and 24 define. a. generally, U shaped path for curtain 22. Clutches 29 andc30 areot7 the one-way type arranged to drive in.opposite:direc:- tions and to slip when the otherclutch isina adriving condition. The brackets 28 may contain. retarding: means to prevent slack in the curtain.
The drive for rollers 23 and.24isfromaureversirble; motor 38 through a gear box 39 mounteditosidefname member 13 through support members 4lltqThe'rollers. are driven through a gear train comprisinggeartliliom the shaft of gear box 39, gears 42", 43*andr44irallrof FIG. 3 is a view seen in the plane of lines13-3 of FIG.
which are mounted on shafts rotatably mounted in the end wall 13; as well as gears 31 and 32.
When motor 38 is operated a direction to drive gear 41 in a counterclockwise direction as viewed in FIG. 3, then clutch will be engaged and the curtain will be drawn from roller 23 to roller 24. At this time, clutch 29 will be disengaged. When the direction of motor 38 is reversed clutch 29 will drive and the curtain will be taken up on roller 23.
As shown in FIG. 4 illustrating a section of the curtain, the curtain 22 is gene rally opaque and the destinatio'n intelligence is translucent. Therefore, the destination intelligence will be backlighted by a lamp source shown as fluorescent lamp 46. Lamp 46 mounted between sockets 47 extending from the side frame mem ber 13 provides a source for light transmission through the position code marks 48 associated in a fixed relation to each of the destinations on the curtain. Each of the position codes includes a block 48a disposed beyond the destination on the curtain so that the photocells will not be fooled by light passing the destination letters. Also associated with each exterior destination display and coding is an interior destination display 49 for which a window in the back cover (not shown) may be provided.
The arrangement described permits backlighting of the outside destination display and also operation of the position coding and logic from a single lamp source.
In positioning the curtain to display a given destination the vehicle operator or conductor will operate a reference number selector where each member corresponds to a given destination on the curtain.
As shown in FIG. 5, a comparator 50 compares the actual position number (P) sensed by photocells 21 with a reference number (R) set by a selector 51 which may comprise a multiple position rotary switch and suitable coding logic. The comparator is of the type adapted to compare two numbers (R and P) and yield signals indicative ofR P, R P, and R P. However, with the logic herein described only R P, and R P need be utilized.
The logic network comprises transistors 52 57, motor directional relays KD and KU together with controlled contacts and control relay KC and controlled contacts, and a timer TD together with a controlled contact. Transistor 52 is normally off, and only turns on when a signal R P is sensed from comparator 50. Transistor 54 is turned on to operate motor 38 in a first direction when a new curtain position is commanded. Transistor 55 is responsive to a signal that P R and acts to reverse the operation of motor 38. Transistor 53 acts as a latch on transistor 52 and also to open a latching circuit established about relay KC. Transistor 57 acts as a switch to turn off transistor 56.
When selector 51 is set to the desired position and switch 58 is closed, relay KC is energized. The contacts KC close to latch in relay KC through transistor 56, and to apply B-lto line 60, and the collector of transistor 52. Transistor 52 is off in the absence of a P R signal from comparator 50. A base drive is applied to transistors 53 and 54 over line 60a. When time delay TD times out it closes contact TD and 8+ is applied to the collectors of transistors 53 and 54. When contact TD closes, relay KD is energized and closes its contacts to energize motor 38. Motor 38 turns in a direction to drive roller 24 and roll curtain 22 from roller 23 to roller 24. When operating in this direction the position numbers (P) increase in numerical value; however, so long as the selected number R is greater than P, the curtain will continue in this direction until comparator 50 signifies that P R. Then a high signal is applied to the base of transistor 52 which turns on. The collector of transistor 52 goes low as does the base of transistor 54. Transistor 54 turns off and relay KD is deenergized, dropping out its contacts to de-energize motor 38. At the same time, the base of transistor 53 goes low and transistor 53 turns off. The higher voltage at the collector of transistor 53 turns on transistor 57, and the resulting drop in voltage at the base of transistor 56 turns off transistor 56. Relay KC is then deenergized dropping out its contacts, delay circuit TD is dropped out, B-lto transistors 53 and 54 is terminated and the network is inactive.
If when the curtain started to move on roller 24, the initial P number sensed was greater than R indicating that the curtain should be rolled onto roller 23, a signal P R would be applied to transistor 55 to turn it on. Relay KU would be energized, and open its contact in series with transistor 54, and close its contacts in the motor circuit. At this time, transistor 52 is off and transistor 53 is on. The motor will run to wind the curtain on roller 24 until the P R disappears and the P R signal appears and turns on transistor 52. When this occurs transistor 53 turns off and the circuit operation thereafter is as previously described.
The logic described above provides a simplified bidirectional motor positioningcontrol. In cases where P R initially, this non-equality will generally be sensed from the position number on the stationary curtain by photocells 21 before the curtain moves, due to the time delay. In any event, practice has shown that if the curtain commences to move when KD is energized and P R, the curtain will be reversed after advancing one destination. Therefore, the logic as described eliminates the need for an R P signal and the circuitry that would be necessary to utilize such signal.
The curtain 22 may be arranged with the display information and code translucent and the background opaque or vice versa. In the latter case, the photosensitive elements would be responsive to the absence of light. The term translucent as used herein refers to the selected areas of the curtain being capable of transmitting light and would include the condition of selected areas of the curtain being transparent.
While it is preferred to utilize an elongated curtain with the display and accompanying position code information displayed along the length thereof in order to provide room for a large number of displays, the invention may be practiced with an endless curtain as shown in FIG. 6. In FIG. 6 an endless curtain 60 moves over one or more drive rollers 61 and 62 of the type described which may be connected by a gear train (not shown) and loop about guides or idler rollers 63 67. A single light source 68 is disposed within the outline of curtain 60. The coding information is inlcuded on the curtain in the area A adapted to be sensed by photo-sensitive devices 69. The display is in the area B.
In another arrangement shown in FIG. 7, the display intelligence in the area C and the position code information area D may be arranged so that C and D reside in transverse planes as a curtain 70 passes over a guide 71 between drive rollers 72 and 73. A single light source 74 backlights the display and transmits light through the code to photocells 75.
In general, the rollers and guides are so arranged that a portion bearing a display resides in one plane, and the portion bearing the accompanying position code resides in another plane.
It may thus be seen that the objects of the invention set forth as well as those made apparent from the preceding description are efficiently attained. While preferred embodiments of the invention have been set forth for purposes of disclosure further embodiments of the invention as well as modifications to the disclosed embodiments which do not depart from the spirit and scope of the invention may occur to others skilled in the art. Accordingly, the appended claims are intended to cover all embodiments and modifications of the invention which do not depart from the spirit and scope of the invention.
What is claimed is:
1. A display device comprising a housing member, a curtain having a plurality of displays thereon and a code associated with each display in predetermined relation therewith, curtain guide means in said housing, first and second spaced apart rollers, said curtain being movable on said guide means between said rollers to position said displays in a predetermined position for viewing, lighting means for simultaneously illuminating said displays for viewing and said codes for curtain position sensing, photo-sensitive means for sensing the codes, said photo-sensitive means being positioned and supported in relation to said curtain to continuously sense said codes on said curtain while a display is positioned for viewing in said predetermined position, means for reversibly driving said rollers, display posi tion selection means, comparator means responsive to said selection means and said photo-sensitive means for actuating said drive means to move said curtain in a first direction in response to an unequal relation of a reference number set by said selection means and a sensed code number, and means responsive to said comparator means sensing that one of said reference number and a code number bears a predetermined relation to the other for reversing said drive means.
2. The device of claim 1 wherein said curtain defines a generally U-shaped path between said rollers, said light source is disposed in the bight of said U-shape, and the display and its associated position code reside in different planes defined by said curtain.
3. A display device comprising an elongated curtain having a plurality of displays thereon and a code associated with each display in predetermined relation therewith, guide means for said curtain, means for moving said curtain on said guide means, lighting means for illuminating said displays and said codes, photo-sensitive means for sensing the codes, destination display selection means, a numerical comparator adapted to compare a code number with a reference number set by said selection means, means responsive to an unequal relation of the reference number and a sensed code number as determined by said comparator for initiating operation of said means for moving said curtain in a first direction, and means responsive to said comparator sensing that one of said reference and a code number bears a predetermined relation to the other for reversing said means for moving.
4. The device of claim 3 wherein said guide means includes a pair of rollers, said means for moving drives said rollers.
5. The device of claim 3 wherein said curtain is formed in an endless loop.