US 2037191 A
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Description (OCR text may contain errors)
April 14, 1936.
F. E. BACKER 2,037,191
REGISTERING DEVICE Filed Sept. 50, 1932 2 Sheets-Sheet l INVEN TOR I F. 5.. HACKER A TTORNEV April 14, 1936. BACKER 2,037,191
REGISTERING DEVICE Filed Sept. 30, 1932 2 Sheets-Sheet 2 REG/SEA INVENTOR ATTORNEY Patented Apr. 14, 1936 UNITED STATES PATENT OFFICE REGISTERING DEVICE Application September 30, 1932, Serial No. 635,506
This invention relates to apparatus for automatically counting or registering persons or objects passing a selected point and more particularly to such apparatus employing light sensitive cells.
An object of the invention is to provide a light responsive counting device for registering the number of persons or objects passing a selected point which is of simple construction, reliable in operation and proof against fraudulent manipulation.
One feature of the present invention provides on one side of a passageway a source of light projecting a sheet or curtain of light normal to the path of the persons or the objects to be counted and means on the opposite side of the passageway for intercepting and reflecting light from a plurality of points in the light sheet, or curtain, on a light sensitive cell controlling a counting mechanism, thereby rendering the counting device less sensitive to partial interruptions of the light screen.
Another feature of the invention provides two light screens and two light sensitive devices, one for operating the counting mechanism when the light screens are interrupted successively by a person or an object passing in one direction, and the other for rendering the counting mechanism inoperative when the light screens are interrupted successively in the opposite direction, both light sensitive devices being under the control of both light screens.
Still another feature of the invention provides a light sensitive device for controlling a counter circuit and a separate light sensitive device for controlling a guard circuit and means associated with the counter circuit to prevent additional count after the counter has been operated until the light is shut off from the light sensitive device controlling the guard circuit.
In accordance with one embodiment of this invention there is provided on one side of a passageway two adjacent sources of light which project vertical sheets of light across the passageway on two sets of reflectors which direct the light from each source on two adjacent photoelectric units, one for operating a registering circuit and the other for operating a guard circuit which limits the operationsof the device to the counting of persons or objects when they move in one direction only.
Referring to the drawings:
Fig. l is a perspective view of the optical apparatus of the counting device in accordance with the invention showing the units partly in sectionand their relative positions when installed on opposite sides of a passageway;
Fig. 2 shows diagrammatically the optical system;
Fig. 3 is a cross-section of one light unit through 3-3 of Fig. 1;
Fig. 4 is a horizontal section through an alternative form of light unit;
Fig. 5 shows a modified form of reflector for the optical system;
Fig. 6 is a partial longitudinal section of ,a modification of the photoelectric unit; and
Fig. 7 shows diagrammatically a circuit suitable for use with the invention.
As shown in Fig. 1 there are on one side of a passageway such, for example, as that used for keeping persons entering a theater or other places of amusement in single file for the purpose of collecing tickets, two similar light sensitive or light detecting units 1 and 8. On the opposite side of the passageway there are two similar light sources or light units 9 and I which project two vertical sheets or curtains of light across the passageway on the detecting units.
The light sensitive unit 1 comprises a casing or hollow column having an open side facing the passageway and the light unit 9. Midway between the top and the bottom of the casin is a horizontal opaque partition ii on opposite sides of which are two photoelectric cells l2 and I3 which are protected from the direct rays of the light units 9 and ill by means of an opaque screen H. In the upper end of the casing and adjustably secured, by any suitable means, to the back 2i thereof are six similar mirrors l to 20, inclusive, adjusted as hereinafter described to reflect the light downwardly on the photoelectric cell I2, and in the lower end of the casing are six similar mirrors 22 to 21, inclusive, to reflect the light upwardly on the photoelectric cell i3. The unit 8 is identical with unit I with the exception of the adjustment of the mirrors. The photoelectric cells i2 and I3 are connected in multiple to the counting circuit by means of conductors 28 and 29 and the photoelectric cells l2 and E3 of unit 8 are connected in multiple by means of conductors 28' and 29' to the guard circuit.
The light unit 9, as shown, comprises a vertical casing or hollow column in which are secured two long counter lamps 30 and 3| one standing upright on the base of the casing and the other depending from the top. They project a vertical sheet of light practically the height of the unit. The front of the casing is provided with a vertical slit or opening 33 and behind the lamps is a vertical reflector 34. The light unit 10 is identical with light unit -9 and all of the lamps are connected in multiple to a suitable current supply by means of conductors 35 and 36.
In Fig. 4 there is shown an alternative arrangement for the light units 9 and ID. This has one light source for both light screens making use of two long vertical mirrors 31 and 38 on each side of the lamp to reflect the light through the openings 33 and 33. These mirrors may be considered as separate. light sources.
Fig. 2 represents diagrammatically the optical system of the arrangement shown in Fig. 1. For purposes of illustration and to simplify the description three points have been selected on each of the lamps and the mirrors adjusted accordingly. It will be noted that the light from the lower point of lamp 32 is reflected on the photoelectric cells IS and I3 by mirrors 21 and 21 respectively. (The prime characters represent elements in the photoelectric unit 8 and the light unit ||l similar to those in units 1 and 9, respectively, of the same numbers.) The light from the central point of lamp 32 is reflected on the photoelectric cells l2 and I2 by mirrors l8 and I8, respectively, and the light from the upper point is reflected on cells |3 and I3 by mirrors 23 and 23', respectively. In a similar manner the transmission of light may be easily traced from the three selected points on the lamps 32', 3| and 3|. Actually even with plane mirrors as shown in Fig. 2 the light from a substantial length of filament is reflected. In practice it is also preferable to adjust the mirrors so that they reflect light from different portions of the filament. Practically all the light is then utilized and the interruption of the light from any one lamp or portion thereof on any cell will not necessarily exclude the light from that lamp from any other cell. The number of reflectors depends upon the degree of sensitivity required, the more light reflected the less sensitive the device and therefore the more diflicult it is to defraud by intercepting the light with small objects such as the foot or the hand. The angle A of each wedge-shaped screen should be sufiicient for the light to cover the mirrors intended to reflect it in each unit. The least sensitivity may be obtained by using curved mirrors as shown in Fig. to reflect the light from substantially every point of the source on the photoelectric cell. Suitable curved mirrors may be made of chromium-plated or silver-plated sheet metal or other suitable material. Each mirror is preferably adjustable with respect to the light source. This may be accomplished by any suitable arrangement as a ball and socket joint or as shown in Fig. 5 where a vertical adjustment may be had by a friction hinge 40 and a rotatable adjustment may be had by means of a screw through the back 2| of the casing.
Fig. 6 shows a modification of the cell units 1 and 8 of Fig. 1 in which only one cell 60 is used in each unit with two mirrors BI and 52 for directing the light from the upper and lower mirrors, respectively, as indicated by the arrows.
In Fig. 7 which shows one circuit arrangement suitable for use in the invention there are two photoelectrically controlled circuits, namely, the counter circuit A and the guard circuit B. In the counter circuit A the cells l2 and I3 are connected in parallel in the input circuit of the amplifiers 4| and in series with opposing batteries 42 and 43. Connected between the common terminal of batteries 42 and 43 and theg'rld of the amplifier is a grid resistor 44. This circuit arrangement is commonly known as the reverse circuit, that is, when the cell is illuminated the current in the plate circuit is substantially zero. The input circuit of the amplifier 4 I. in the guard circuit B is identical'with that of the counter circuit A. The filaments of both amplifiers 4| and 4| are supplied with current from the battery 46, and the plate potential of the amplifiers is derived from battery 41 in series with relay .8 in the counter circuit and in series with a relay 49 in the guard circuit.
The relay 48 is provided with two sets of normally open contacts 50 and 5| and the relay 49 is provided with two sets of normally closed contacts 52 and 53. Contacts 52 are in series with the winding of relay 48 and open and close the plate circuit of amplifier 4|. The normally closed contacts 53 and the normally open contacts 5| are in series with each other and with a counter 54 including its own source of current, not shown. The contacts 50 in series with a resistance 55, the relay winding and the battery 41, and the contacts 52 provide a holding circuit for the relay 48.
Under normal operating conditions the light sensitive cells l2 and |3, and I2 and I3 are illuminated and the negative bias on the grid due to the drop of potential across the grid resistors 44 and 44' is sufficient to prevent current from the batteries 42 and 42' from flowing through the plate circuit of the amplifiers 4| and 4|, respectively. When the light cells are dark no current flows through the grid resistors 44 and 44' from the batteries 42 and 42'. The grids then have a positive bias due to the batteries 43 and 43 and current will flow in the plate circuit.
The operation is briefly as follows: A person or object passing in the direction indicated by the arrow will first interrupt the light falling on cells I2 and I3 in the counter circuit A. Relay 48 will then be energized and contacts 50 and 5| will be closed, the latter operating the counter 54 and the former completing a hold-up circuit for the relay 48 through the resistance 55, the battery 4'|, relay contact 52 and the relay winding. The object of the hold-up circuit is to prevent the subsequent operation of the counter until a person in passing has interrupted the light from cells l2 and I3 when relay 49 will be energized and open both the circuits through counter 54 and the relay 48. After the person passes the light sensitive cells I2 and I3 light again falls on all cells and the circuit returns to normal. The guard circuit B also prevents the operation of the counter by a person going in the opposite direction. If, for example, the light is first interrupted from the cells I2 and |3'the counter circuit being normal, relay 49 is energized and the contacts 52 and 53 are opened thus preventing the operation of relay 48 and the counter 54. It will be seen, therefore, that the device is unidirectional and that the counter cannot be operated successively by simply cutting oil! the light from the cells in the counter circuit. In practice the two light columns should be as close together as practicable and the cell units should also be close together so that the person or object in passing will at some instant cut off the light from all of the cells.
Although a device has been shown and described as a battery operated device, it may be modified in a manner well known to those skilled in the art of vacuum tube circuits so that it may be used on a direct or alternating current lighting system.
What is claimed is:
1. A counting device for registering the number of persons or objects passing a selected point in one direction only comprising a source of light, means for projecting the light beam from said source in the form of a vertical sheet across the path of the person or the object, a circuit including a counter, a light sensitive unit for controlling said circuit and counter, said unit being disposed on the opposite side of the path from the light source, and means disposed above and below said unit for intercepting and reflecting the light rays from a plurality of spaced points in said beam and focusing them on said unit.
2. A counting device for registering the number of persons or objects passing a selected point in a given direction, a source of light means for projecting the light beam from said source in the form of a vertical sheet across the path of the person or the object, a circuit including a counter and a photoelectric cell for controlling said counter, said cell being disposed on the opposite side of the path from said light source, and means disposed above and below said cell for intercepting and reflecting the light rays from a plurality of points in said beam and focusing them on said cell.
3. A counting device for registering the number of persons or objects passing a. selected point in one direction only, means projecting two vertical sheets of light normal to the path of the person or the object, a circuit including a counter and a light sensitive unit controlling the counter, a second circuit including a separate light sensitive unit for preventing the operation of said counter by said first circuit when a person or object passes in the opposite direction, and means reflecting and directing the light from each light sheet on both of the light sensitive units.
4. A counting device for registering the number of persons or objects passing a selected point, comprising a light source on one side of said point, means for projecting a vertical sheet of light from said source normal to the path of the person or object passing said point, a register, two light sensitive devices operably associated with said register opposite said light source, and means disposed substantially vertical above and below said light sensitive devices for reflecting the light rays from various points of said source on each of said devices.
5. A counting device for registering the number oi. persons or objects passing a selected point in one direction only, comprising a register, a light sensitive unit and a light source defining a path, a housing for said light source having an elongated vertical slit through which is projected a vertical sheet of light, said light sensitive unit comprising an elongated vertically disposed casing, a plurality of light sensitive cells disposed between the ends of the casing, means for shading said cells from the direct rays of said source, a partition between said cells and reflecting means at each end of said casing for reflecting and directing rays of said source on each of said cells, and means associated with said cells for operating said register.
6. A counting device for registering the numberof persons or objects passing a given point comprising a counting circuit having a light sensitive cell, a relay controlled thereby and a counter controlled by said relay, a holding circuit for said relay to prevent the false operation of said counting circuit, and a guard circuit including a second light sensitive cell and a second relay controlled by said second cell for opening said holding circuit to release said first relay and conditioning said counting circuit for subsequent operation.
'7. A counting device for registering the number of persons or objects passing a selected point in one direction only, comprising a register, two light sensitive units disposed side by side and two light sources disposed side by side forming with said light sensitive units a passageway, means for projecting a light beam in the form of a vertical sheet of light from each of said light sources on each of said light sensitive units, means associated with one of said light sensitive units for operating said register when an object passing in one direction interrupts the light on that unit, and means associated with the other light sensitive unit for preventing the operation of said register when an object passing in the opposite direction interrupts the light on said other unit.
8. A counting device for registering the number of persons or objects passing a given point comprising a light unit, a light sensitive device, said unit and said device defining a passage and a circuit including a counter and said light sensitive device, said light unit comprising elongated light sources disposed vertically, means for supporting said light sensitive device substantially midway between the uppermost and the lowermost horizontal rays from said sources and means for deflecting substantially said rays and other rays therebetween on said light sensitive device.
FRANKLYN E. BACKER.