US3676759A

US3676759A - On-off motor control push button switch for photographic apparatus

Info

Publication number: US3676759A
Application number: US74353A
Authority: US
Inventors: Helmut Mayr; Richard Pelte; Theo Hubert; Helmut Strasser
Original assignee: Agfa Gevaert AG
Current assignee: Agfa Gevaert AG
Priority date: 1969-09-26
Filing date: 1970-09-22
Publication date: 1972-07-11
Anticipated expiration: 1989-07-11
Also published as: DE1948631A1; DE1948631B2

Abstract

Pressing a release turns on, or triggers, a bistable electronic switch, such as a multivibrator or a semiconductor tetrode, which in turn renders an amplifying transistor conductive through which an electromagnet is energized, closing a switch that operates the motor of the photographic apparatus. Re-pressing the release shuts off, or reverses the state, of the bistable switch, and thereby turns off the amplifying transistor. Another release is so connected that the bistable multivibrator is conductive, or triggered to the right state, as long as the release is depressed. The two releases can be combined into a single release by using a selector switch.

Description

United States Patent Mayr et a1. 1 1 July 11, 1972 s41 ON-OFF MOTOR CONTROL PUSH [56] MM cm BUTTON SWITCH FOR UNlTED STATES PATENTS PHOTOGRAPHIC APPARATUS 2,962,634 1 1/1960 Griffin ..307/112 X 1 Inventors: Helm! y Richard 3,428,830 2/1969 McEvoy ..328/206X bert; l m m. all of Munich. 3,290,551 12/1966 Cake .307/252.26 x many 3,064,522 11/1962 Fukuoka............ ...........3l8l446 X [73] Assignee: gla-Gevaert Aktlengesellschalt, Munich, Primary fixaminer l D'Miller "many Assistant ExaminerRobert .I Hickey [22] Filed: Sept. 22, I970 Attorney-Michael S. Striker [21] Appl. No.: 74,353 57 ABSTRACT Pressing a release turns on, or triggers, a bistable electronic 8" Allpuflfion switch, such as a multivibrator or a semiconductor tetrodc, which in turn renders an amplifying transistor conductive Sept. 26, 1969 Germany ..P 19 48 631.8 through which an elect-roman is energized, closing a switch that operates the motor of the photographic apparatus. Re- [52] 1.1.5. CL ..318/446, 2301070115296 3305721113728, I P 8 the release shuts om or reverses the mate of the l 1 In. C um bistable switch, and thereby turns 011 the amplifying transistor.

d that h M [58] FieldolSeamh ..307/112,113, 132, 252 o, 247 A, Ammemkm'swmnma': m mumwbmm is conductive, or triggered to the right state, as long as the release is depressed. The two releases can be combined into a single release by using a selector switch.

l0Clahns,4DrawlngFlgures s Ln PATENIEDJUL 1 I I972 3.6 76, 7 59 saw 1 OF 1 IN V EN TOR HELMUT STRASSER HELMUT MAYR BY RICHARD PELTE THEODO UBER 141/04! fi ffprfi PATENTEUJUL 1 1 4912 sum :2 BF 4 [NI EN TOR HELMUT STRASSER HELMUT MAYR BY RlCHARD PELTE THEODOR UBER PATENTEDJUL 1 1 1912 3. 676 T59 sum 3 or a INVENTOR ama BY RICHARD PELTE THEODOR HUBER If? [/f'll/ PKTENTEDJUL 1 H972 SHEEI B [If 4 INVENTOR HELMUT STRASSER BY HELMUT MAYR RICHARD PELTE THEODOR HUBER 4 ,m/ I a m ##r a ON-OFF MOTOR CONTROL PUSH BUTTON SWITCH FOR PI-IOTOGRAPI'IIC APPARATUS BACKGROUND OF THE INVENTION The invention relates to motor control arrangements for photographic apparatus, such as motion picture cameras and photographic cameras, having an electric motor for driving the mechanism of the camera.

Motor control arrangements of the prior art incorporate, as a rule, switches that must be manually actuated for as long as the drive motor is to be in operation.

SUMMARY OF THE INVENTION An object of the invention is to provide motor control arrangements for photographic apparatus, wherein the arrangement keeps the motor energized after a switch means of the arrangement is freed.

The invention consists essentially of electronic amplifier means having a conductive and a non-conductive state, electromagnetic means connected to the amplifier means to be energized when the latter is in its conductive state, motor switch means for the motor operated by the electromagnetic means to close and open when the latter is energized and deenergized, respectively, thereby turning the motor on or off, manually operated switch means, and bistable electronic switch means connected to the amplifier means and to the manually operated switch means to render the amplifier means alternately conductive and non-conductive upon operation of the manually operated switch means, whereby the motor is alternately turned on and off.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a schematic diagram of a first embodiment of the invention;

FIGS. 2 and 3 are further schematic diagrams of two additional embodiments of the invention; and

FIG. 4 is an embodiment of the invention employing a diaphragm switch.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, a voltage source I is connected by an operating switch 2 to the circuit arrangement. A capacitor 3 and a resistor 4 connected in series are shunted across the voltage source 1. The common junction between the capacitor 3 and the resistor 4 is connected by way of a switch 6, operated by a release element 5, to the base of an amplifying transistor 7. A spring 8 biases the release element 5, which latter incorporates a slanting shoulder 9 that operates the switch 6. The base of the transistor 7 is connected by a resistor 10 through the operating switch 2 to the negative pole of the voltage source 1. The emitter of the transistor 7 is connected directly to the switch 2. The collector of transistor 7 is connected through an electromagnet 11 to the positive pole of the voltage source 1. The electromagnet ll actuates a switch 12, which, when closed, connects an electric motor 13 directly to the switch 2, which latter connects the motor across the voltage source I. A resistor 14 and a capacitor 15 are connected in series with the motor 13, the switch 12, when closed, causing a short across the resistor 14 and capacitor 15.

Two

contact electrodes

16 and 17 of a semiconductor tetrode l8 connect the latter across the switch 6. The tetrode is a four-layer semiconductor with alternating positive and negative doped layers. A resistor 20 connects the control electrode 19 of the tetrode to the positive pole of the voltage source I. When the operating switch 2 is closed a resistor 22 connects the other control electrode 21 of the tetrode to the negative pole of the voltage source I. The control electrode 2] is abo connected by a switch 23 to the junction between the capacitor 15 and the resistor 14. The switch 23 is operated by slanting shoulder 24 of a further release element 25, which latter is biased by a spring 26.

The circuit just described operates in the following manner. It will be assumed that only the release element 5 is operated. First of all, the operating switch 2 is closed, whereupon the capacitors 3 and I5 charge themselves to the full voltage of the source 1. When, now, the release element 5 is pushed in the direction of the arrow A the slanting shoulder 9 closes the switch 6. After the latter is closed the positive potential of the capacitor 3 is conducted to the base of the transistor 7, causing the latter to be turned on hard. Consequently, sufiicient current flows through the electromagnet ll to attract the armature of the latter. In a manner not shown the electromagnet ll closes the switch 12, whereby the electric motor I3 is connected across the voltage source I, turning the motor on. The capacitor 3 discharges through the resistor 10, so that after a predetermined time there is at the base of the transistor 7 a voltage determined by the ratio between the

resistors

4 and 10. The transistor 7, which had been turned hard on, is now somewhat less conductive, but sufficient current still flows in its emitter path to keep the armature of the electromagnet l l attracted. If the photographer releases the element 5, the switch 6 opens, and the transistor 7 is turned off. The electromagnet 11, therefore, is de-energized, and the switch 12 opens. The motor 13, consequently, is shut 011'.

It will now be assumed that only the release element 25 is operated. When the element 25 is moved in the direction of the arrow B, the slanting shoulder 24 closes the switch 23. The capacitor 15, which has previously been charged to the full voltage of the source I, is connected with its positive plate to the control electrode 21 of the semiconductor tetrode 18. The resulting positive pulse turns on the tetrode I8, thereby connecting the positive plate of the previously charged capacitor 3 to the base of transistor 7. The transistor 7 is turned on hard, and the electromagnet II is energized, thereby closing the switch 12 and energizing the electric motor 13. As soon as the switch 12 is closed, the capacitor 15 begins to discharge through the resistor 14. By suitably choosing the values of the resistor 14, and the capacitor 15, the discharge occurs so slowly that it has no effect on the tetrode 18. Once the motor I3 is started up, the photographer can release the element 25. In other words, the release 25 is only momentarily depressed.

When the motor 13 is to be shut off, the release element 25 is again pressed, reclosing the switch 23. Since the plate of the capacitor I5 connected to the resistor 14 is negative after the capacitor is discharged, a negative pulse is conducted to the control electrode 21 of the tetrode I8. The tetrode 18 is thereby rendered non-conductive, shutting off the transistor 7. The electromagnet II is therefore de-energized, and the switch I2 is opened; and the motor I3 is shut ofl.

With reference to the embodiment shown in FIG. 2, all of those components that play the same role that they do in FIG. are denoted by the same reference numerals. A release element 30 is biased by a spring 31, the slanting shoulder 32 of the release element operating the switch 6. A selector switch W is shown in its D-D position, in which it connects switch 6 with the base of transistor 7. The selector switch comprises two ganged two-pole switches with respective

movable contacts

33 and 34, which are connected to the switch 6. In the other position l-l of the selector switch W, the switch 6 is connected to the control electrode 21 of the semiconductor tetrode 18, which latter in this embodiment, as in the previous embodiment, acts as a bistable electronic switch.

If the operating switch 2 is closed, the release element 30 moved in the direction of the arrow C, and the selector switch W moved to its position D-D, as shown in FIG. 2, the electromagnet 11 is energized, as in accordance with the embodiment shown in FIG. I, and the electric motor 13 turned on as long as the release element 30 is depressed, and consequently the switch 6 is kept closed. The circuit operates in precisely the same way as does the circuit of the previous embodiment.

If the selector switch is moved in the direction of the arrow E to its position I] and the release element 30 is pressed, the tetrode 18 is turned on through the switch 6, as in the first embodiment, and the electric motor 13 is turned on. If the element 30 is released and then again pressed, the tetrode I8 is turned off, as in the first embodiment, and the motor 13 is deenergized. In this instance also the circuit operates precisely in the manner of the previous embodiment.

The release elements and 25, or the release element 30, can be replaced by diaphragm switches. The embodiment shown in FIG. 4 illustrates the case in which the release element 30 is replaced by a diaphragm switch 65. The switch 6 is arranged in the camera housing 59 and operated by a lever 60 mounted to pivot about a pin 61. The lever is biased by a spring 62, and is limited in its clockwise movement by a stop 63. The lever 60 comprises an arm 64 that contacts the diaphragm switch 65. If the diaphragm switch 65 is pressed upon in the direction of the arrow F, the lever 60 is pivoted against the force of the spring 62 in the direction of the arrow G, so that the shoulder 66 of the lever 60 closes the switch 6. All other operations of the circuit 4 are precisely the same as described in connection with the embodiment shown in FIG. 2.

In precisely the same way the membrane switch shown in FIG. 4 can also be used to replace the release element 30 employed in the embodiment shown in FIG. 3, which latter embodiment will now be described.

All components in this embodiment that have the same function as in the previous embodiments are denoted by the same reference numerals. With reference to FIG. 3, a switching transistor 40 connects the positive plate of the capacitor 3 to the base of transistor 7. The base of transistor 40 is connected to the collector of a transistor 41 of a bistable switch means, here in the form of a bistable multivibrator. A resistor 42 is connected to the collector of transistor 41. This collector is also connected to a voltage divider comprised of resistors 43 and 44, the common junction of which is connected to the base of the other transistor 45 of the bistable multivibrator. A resistor 46 is connected to the collector of this latter transistor. This collector is also connected to a voltage divider comprised of

resistors

47 and 48 the common junction of which is connected to the base of the transistor 41. A capacitor 49 is shunted across the resistor 43. The emitters of the transistors 41 and 45 of the bistable multivibrator are connected together, and are connected to the positive pole of the voltage source 1 by a resistor 50 and a capacitor 51 connected in parallel. The base of transistor 45 is connected by a decoupling capacitor 52 to the selector switch W.

The circuit just described operates in the following manner. If the operating switch 2 is closed, the capacitor 49 conducts a negative pulse to the base of transistor 45, thereby turning the latter on. Consequently, the base of transistor 41 receives a positive pulse, so that this transistor is turned off. The base of transistor 40 is therefore negative, and this transistor, as well as transistor 7, is also turned 011'.

If the selector switch W is in its position l-I and the release element 30 is pushed in the direction of arrow C, the switch 6 is closed, and a positive pulse is conducted through the capacitor 52 to the base of transistor 45 of the bistable multivibrator. Transistor 45 is turned ofi, whereas transistor 41 is turned on through the feedback path composed by the

resistors

47 and 48. The base of the switching transistor 40 is positive, thereby turning on both this transistor and transistor 7. As previously described, the electromagnet 11 is energized and, after closing of the switch 12, the motor 13 is turned on.

If after a determined time the switch 6 is again closed, a negative pulse is conducted to the base of transistor 45 since the capacitor is discharged. Transistor 45 is turned on hard, and transistor 41 is once again turned 05, thereby turning off the switching transistor 40 and the amplifying transistor 7. Thus, the electromagnet 11 is de-energized, and the motor 13 is shut off.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of circuits differing from the types described above.

While the invention has been illustrated and described as embodied in a motor control for photographic apparatus, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended 1. In a motor control arrangement for photographic apparatus having an electric motor for driving the mechanism of the apparatus, in combination, electronic amplifier means having a conductive and a non-conductive state; electromagnet means connected to said amplifier means to be energized when the latter is in said conductive state; motor switch means for the motor operated by said electromagnet means to close and open when the latter is energized and de-energized, respectively, thereby turning the motor on or off; manually operated switch means; bistable electronic switch means connected to said amplifier means and to said manually operated switch means to render said amplifier means alternately conductive and non-conductive upon operation of the manually operated switch means, whereby the motor is alternately turned on and off, said amplifier means having an input and said bistable electronic switch means being a semiconductor tetrode having two contact electrodes and two control electrodes, said two contact electrodes being connected to said amplifier means input, and one of said control electrodes being connected to said manually operated switch means, said manually operated switch means comprising first and second switch means, said first switch means being connected across said two contact electrodes of said tetrode and said second switch means being connected to said one control electrode of said tetrode.

2. In a motor control arrangement as defined in claim 1, including respective switch operating release means for actuating each of said first and second switch means.

3. In a motor control arrangement as defined in claim 2, wherein each of said release means is a diaphragm switch.

4. In a motor control arrangement for photographic apparatus having an electric motor for driving the mechanism of the apparatus, in combination, electronic amplifier means having a conductive and a non-conductive state; electromag net means connected to said amplifier means to be energized when the latter is in said conductive state; motor switch means for the motor operated by said electromagnet means to close and open when the latter is energized and deenergized, respectively, thereby turning the motor on or off; manually operated switch means; bistable electronic switch means connected to said amplifier means and to said manually operated switch means to render said amplifier means alternately conductive and non-conductive upon operation of the manually operated switch means, whereby the motor is alternately turned on and off, said amplifier means having an input and said bistable electronic switch means being a semiconductor tetrode having two contact electrodes and two control elec trodes, said two contact electrodes being connected to said amplifier means input, and one of said control electrodes being connected to said manually operated switch means; switch-operating release means for operating said manually operated switch means; and two-position selector switch means for connecting said manually operated switch means across said two contact electrodes of said tetrode, in one position, and to said one control electrode of said tetrode, in the other position.

5. in a motor control arrangement as defined in claim 4, including switch operating release means for operating said manually operated switch means.

6. in a motor control arrangement as defined in claim 5, wherein said release means is a diaphragm switch.

7. In a motor control arrangement as defined in claim 4, wherein said selector switch means comprises two ganged switch means having each a movable contact connected to said manually operated switch means.

8. In a motor control arrangement for photographic apparatus having an electric motor for driving the mechanism of the apparatus, in combination, electronic amplifier means having a conductive and a non-conductive state; electromagnet means connected to said amplifier means to be energized when the latter is in said conductive state; motor switch means for the motor operated by said electromagnet means to close and open when the latter is energized and deenergized, respectively, thereby turning the motor on or 05; manually operated switch means; bistable electronic switch means connected to said amplifier means and to said manually operated switch means to render said amplifier means alternately conductive and non-conductive upon operation of the manually operated switch means, whereby the motor is alternately turned on and ofi, said amplifier means having an input and said bistable electronic switch means being a semiconductor tetrode having two contact electrodes and two control electrodes, said two contact electrodes being connected to said amplifier means input, and one of said control electrodes being connected to said manually operated switch means, said amplifier means including a transistor, said electromagnet means being connected to the collector of said transistor; an output circuit for said tetrode; voltage-dividing means comprising series-connected resistance means and capacitance means, said manually operated switch means and said tetrode output circuit connecting the base of said transistor to the common junction between said series-connected resistance means and capacitance means; voltage source means; resistance means for connecting said one control electrode of said tetrode to one pole of said voltage source means; first capacitor means connected in series with the motor, said manually operated switch means connecting said one control electrode to said first capacitor means.

9. in a motor control arrangement as defined in claim 8, including first resistance means connected in series with said first capacitor means.

10. In a motor arrangement as defined in claim 9, wherein said motor switch means when closed connects the motor directly to said voltage source means and shorts said seriesconnected first capacitor and resistance means.

Claims

1. In a motor control arrangement for photographic apparatus having an electric motor for driving the mechanism of the apparatus, in combination, electronic amplifier means having a conductive and a non-conductive state; electromagnet means connected to said amplifier means to be energized when the latter is in said conductive state; motor switch means for the motor operated by said electromagnet means to close and open when the latter is energized and de-energized, respectively, thereby turning the motor on or off; manually operated switch means; bistable electronic switch means connected to said amplifier means and to said manually operated switch means to render said amplifier means alternately conductive and non-conductive upon operation of the manually operated switch means, whereby the motor is alternately turned on and off, said amplifier means having an input and said bistAble electronic switch means being a semiconductor tetrode having two contact electrodes and two control electrodes, said two contact electrodes being connected to said amplifier means input, and one of said control electrodes being connected to said manually operated switch means, said manually operated switch means comprising first and second switch means, said first switch means being connected across said two contact electrodes of said tetrode and said second switch means being connected to said one control electrode of said tetrode.

4. In a motor control arrangement for photographic apparatus having an electric motor for driving the mechanism of the apparatus, in combination, electronic amplifier means having a conductive and a non-conductive state; electromagnet means connected to said amplifier means to be energized when the latter is in said conductive state; motor switch means for the motor operated by said electromagnet means to close and open when the latter is energized and deenergized, respectively, thereby turning the motor on or off; manually operated switch means; bistable electronic switch means connected to said amplifier means and to said manually operated switch means to render said amplifier means alternately conductive and non-conductive upon operation of the manually operated switch means, whereby the motor is alternately turned on and off, said amplifier means having an input and said bistable electronic switch means being a semiconductor tetrode having two contact electrodes and two control electrodes, said two contact electrodes being connected to said amplifier means input, and one of said control electrodes being connected to said manually operated switch means; switch-operating release means for operating said manually operated switch means; and two-position selector switch means for connecting said manually operated switch means across said two contact electrodes of said tetrode, in one position, and to said one control electrode of said tetrode, in the other position.

8. In a motor control arrangement for photographic apparatus having an electric motor for driving the mechanism of the apparatus, in combination, electronic amplifier means having a conductive and a non-conductive state; electromagnet means connected to said amplifier means to be energized when the latter is in said conductive state; motor switch means for the motor operated by said electromagnet means to close and open when the latter is energized and deenergized, respectively, thereby turning the motor on or off; manually operated switch means; bistable electronic switch means connected to said amplifier means and to said manually operated switch means to render said amplifier means alternately conductive and non-conductive upon operation of the manually operated switch means, whereby the motor is alternately turned on and off, said amplifier means having an input and said bistable electronic switch means being a semiconductor tetrode having two contact electrodes and two control electrodes, said two contact electrodes being connected to said amplifier means input, and one of said control electrodes being connected to said manually operated switch means, said amplifier means including a transistor, said electromagnet meaNs being connected to the collector of said transistor; an output circuit for said tetrode; voltage-dividing means comprising series-connected resistance means and capacitance means, said manually operated switch means and said tetrode output circuit connecting the base of said transistor to the common junction between said series-connected resistance means and capacitance means; voltage source means; resistance means for connecting said one control electrode of said tetrode to one pole of said voltage source means; first capacitor means connected in series with the motor, said manually operated switch means connecting said one control electrode to said first capacitor means.

10. In a motor arrangement as defined in claim 9, wherein said motor switch means when closed connects the motor directly to said voltage source means and shorts said series-connected first capacitor and resistance means.