DE1272713B - Circuit arrangement for the sequential activation of an automatic exposure system and the shutter including film transport in a motion picture camera - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

G03b

German class: 57 a -43

Number: 1272713

File number: P 12 72 713.8-51 (L 57287)

Filing date: August 24, 1967

Opening day: Wed 11, 1968

There are automatic exposure systems on motion picture cameras known that are used for the photoelectric Receiver have their own feed battery. In such cameras, the photoelectric one Receiver when it is in the dark, and this is generally when the Camera the case, very high resistance, so that because of the extremely low power consumption in this case there is no need to install an off switch in the circuit.

On the other hand, it is different with cameras in which the automatic exposure control has a stabilization circuit is fed from the engine battery as well as with bridge or differential circuits. Consumed here the automatic exposure even then power, if the photoelectric receiver of the camera is in the dark. An off switch is essential here. However, this must be done before starting of the camera, and so early that the diaphragms move according to the respective have adjusted the room brightness.

There are already some suggestions for this. So you can turn the switch for the exposure controller in the handle of the camera. It is activated automatically when the camera is picked up. This switch is difficult to use when the camera is placed on a tripod. It is also possible to design the operating switch of the camera as a sequence switch, its first contact is assigned to the automatic exposure. You then press the button of the switch to the pressure point and holds it in this position until the automatic exposure control has reached its target position. Disadvantageous here is that the user is reluctant to push the power button all the way down and then again Receives incorrectly exposed images. The installation of an operating switch should also be considered here, the can shut off the power supply from the battery in its entirety. A conspicuous warning signal can be given to the user show when the power is on and when it is not. Finally it would be possible by pressing a single switch, the automatic exposure is activated and the camera is delayed in To put operation. If a constant delay time is provided for this, then this time would have to be approximately select the same time it takes the diaphragm to move from one end position to the other. That however, it takes several seconds with a motorized shutter. And this time turns out to be too long deems.

The object on which the invention is based is to remedy this situation.

Circuit arrangement for the logical
Activation of an automatic exposure and the shutter including film transport for one
Motion picture camera

Applicant:

Ernst Leitz G. m. B. H.,

6330 Wetzlar, Laufdorfer Weg

Named as inventor:

Dr. Werner Holle, 6330 Wetzlar;

Artur Keßler, 6331 Groß Altenstädten

The subject of the invention is a circuit arrangement for sequentially switching on an automatic exposure system and the shutter including film transport in a motion picture camera. This circuit arrangement is characterized by the fact that it contains means which enable the actuation of the Let the shutter and film transport begin when the automatic exposure control controlled diaphragm has approached its target position up to a residual value. These funds can come from a there are voltage-controlled switches parallel to the motor of the automatic exposure control, whose contact is in the power supply to the film drive motor. It is also possible to use the Motor of the automatic exposure controlled via a transistor circuit as voltage-dependent Switch to connect a flip-flop stage which controls the start-up of the film drive motor.

Furthermore, as is already known per se, the circuit arrangement can have a timing circuit controlled component be provided, which after pressing the operating switch after the film drive motor Expiry of the period of time which is equal to or greater than the time it takes to adjust the diaphragms from their one extreme position is required in the other extreme position, applies tension.

The advantage of the new circuit arrangement is that it significantly reduces the adjustment process for the diaphragm shortened without affecting the quality of the recordings made.

Exemplary embodiments of the circuit arrangement are shown in the figures.

809 569/349

3 4

In the example shown in Fig. 1, the feeding terminal of the motor is connected to ground. Parallel

Battery 1 via a switch S ₂ and a double to the motor M ₁ are two resistors R ₈ , R ₇ each in

switch S _{1 placed} on the circuit arrangement. This series with the base-emitter path of a transistor

includes both the motor 2 for the film drive as T ₃ or T ₄ . The collectors of these transistors are

also a motor 3 for the aperture adjustment. The 5 via resistors R ₁₀ , R ₈ and R ₉ , R _n with the stored

Photo resistor 4 of the automatic exposure is connected to sending sources. At the connection point

an ohmic resistor 7 connected in series of the resistors R ₁₀ and R ₈ is the base of a

and, viewed in the direction of light, lies behind the object transistor T ₆ , which at the same time has a resistor

tivblende 5, the opening of which is to be regulated. That was A ₁₂ with the collector of a transistor T ₅

from the components 4 and 7 existing voltage io is connected. This transistor T ₅ is with his

divider, a power amplifier 8 is connected downstream, base-emitter path to resistor R _{11 in} parallel,

the output signals of which feed the servomotor 3. Two switches S ₁ are attached to the emitter of this transistor

A neutral relay Rl _{1 is connected in} parallel and S ₂ downstream of this motor, of which the former is switched on, the normally closed contact T _{1 of} which is double switch with the motor 2. Its one pole is above one in series. When the switch S ₁ is actuated, the resistor R _{13 is} connected to the collector of the transistor T ₆ , both the diaphragm control circuit and the electric circuit. The base-emitter path of this Trandes motor 2 is connected to voltage. In this case, sistors are parallel to resistor A ₁₀ . At the same time, the voltage drops across the components 4 and 7 and the pole of the switch S ₁ is the same across a resistor A ₁₉ , that is, the base and the emitter of a transistor T _{8 are} not right from the start. The aperture of the diaphragm 5 is set, so that 20 is obtained. The collector of this transistor is voltage via a resistor motor 3 and relay Rl _1. This opens stood R ₁₅ and a diode D _{2 is} connected to the collector of the contact T ₁ and prevents the transistor T ₆ from starting.

Motor 2 until the voltage is applied to motor 3. Furthermore, the mentioned pole of the switch is S ₁

has dropped below a predetermined value. Then through a resistor A ₂₀ and a condenser

the relay Rl ₁ drops out and is via the now generator C with the terminal + U _{B of} the one feeding

closed contact T ₁ enables motor 2 to start. Source connected. The base of the capacitor C

The switch S ₁ is followed by a relay Rl ₂ , which is connected to the connection via a Zener diode D ₃

that should respond with a delay. This is connected through the point of diode D ₂ with resistor R ₁₈

the upstream JiC element indicated. The Verde. Also, this point is at the divider point

The delay time corresponds roughly to the time it takes for the 30 of a resistor A ₁₀ and R _{15 to} build up

Aperture 5 needs to be placed in the voltage divider from an extreme position. This voltage divider lies

others to arrive. The relay Rl ₂ with its parallel to a motor M ₂ . Its foot point is over

clock r ₂ is used to start the motor 2 then the collector-emitter path of a transistor T ₈

to leave if, for example, because of too tightly connected to the mentioned pole of the switch S ₁ .

Light conditions the contact r _x does not close. Also 35 the base-emitter path of this transistor will

in rapidly changing light conditions, for example bridged by a resistor R ₁₁ , which is connected to a

wise when swiveling , the relay _{Rl 2} of the series resistor A ₁₄ and the collector-emitter path

part, because it prevents the stopping of the film drive of a transistor T _{7 is} in series and across this

by responding again to relay JiZ ₁ . is connected to the + U _B terminal. The basis of this

In the figure, mechanical switches are shown, 40 transistor T ₇ is with the dividing point between the

which of course are connected by electronic switches to resistors R ₁₆ and R ₁₅ ,

can be replaced. It is also possible, instead of one pole of a switch S _4, is connected to the base of the

of the delayed relay Rl ₂ a memory arrangement, transistor T ₉ connected. The second pole of the

z. B. to use a flip-flop circuit, which is from the age S ₁ , to which the switch S _{2 is} parallel, is with

Relay JiZ _{1 is also} controlled and for so long in its 45 one input terminal of a voltage converter

Position remains until the switch S _{1 is connected} to its idle SpW , its second input terminal via

situation has returned. a switch S ₃ at the terminal + XJ _{B of} the one

The switch S ₂ allows the exposure auto-feeding source to be located. The output voltage U ₂

matic alone to put into operation and the diaphragm 5 of this converter is used to feed the from the

50 components FW, R ₁ , R ₂ and Ji ₃ assembled on the correct components before the start of the recordings

set the exposure value. Ground bridge circuit.

FIG. 2 shows a circuit arrangement, the mode of operation of that shown in FIG

in which the automatic iris can be switched off The arrangement is as follows:

The two transistors T ₁ and T ₂ form one can be carried out with the cross-fades during the recording. A bridge circuit which is controlled by one of the resistors FW, R ₁ , R ₂ , R ₃ is selected as the exposure meter circuit 55 current amplifier, which is connected to the bridge circuit. Photoresistor FW and three adjustable resistors The resistors Ji ₁ , R ₂ , R ₃ are included for the purpose of the states R ₁ , R ₂ and R _& . Between the resistance input of exposure parameters in their resistors R ₂ and Ji ₃ , a diode D _{1 is} placed, the level values of which are adjustable. Via the diode D ₁ , connections with the bases of two transistors ^, T ₂ 60, the two transistors T ₁ and T ₂ , are connected to a bias voltage. The emitters of these transistors are connected to one another via these transistors and the two resistors Ji ₄ , Ji ₅ , if R ₁₁ and R _{5 would} drive a quiescent current, the collectors of the transistors are connected to the resistors that stabilize the quiescent current. Will supply voltages + TJ _B and - U _B. The connecting bridge is detuned, one of the two connection points of the resistors R ^ R ₅ is blocked at one of the 65 transistors, while the other stronger pole of a two-pole changeover switch S _{4 is} placed, which conducts and drives _{a current through the MOTORM 1.} Switching arm with one terminal of this motor is a servomotor for the aperture B, which motor M _{1 is} connected. The second connection is connected upstream of the photoresistor FW.

The amplifier and thus also the motor M ₁ are fed from two series-connected voltage sources (not shown), while the bridge is supplied with a higher supply voltage via a voltage converter which is known per se and is therefore not further described here. By actuating the switch S ₃ , the voltage converter is de-energized and the automatic exposure is disabled.

As described above, the motor M ₂ , which is used to transport the film to the camera, should only start when the bridge has been largely aligned. In addition, however, the motor M ₂ should be able to start up by means of a switch in spite of the detuning of the bridge, if this is expressly desired, for example in the case of a cross-fade.

The voltage present at the motor M ₁ is a measure of the detuning of the bridge. This voltage is monitored by the transistors T ₃ and T ₄ in connection with the resistors R ₆ and R ₇ . If the voltage at the motor M _{1 is} greater than about 0.5VoIt, one of the transistors becomes conductive depending on the polarity of this voltage. If, on the other hand, the voltage at the motor falls below 0.5VoIt, which is equivalent to an incorrect exposure of less than half a light value, both transistors are blocked.

_{If transistor T 3 was} conductive before both transistors were blocked, transistor T _{6 is} blocked via resistors R ₈ and R _10. If, on the other hand, transistor T _{4 was} conductive, transistor T ₃ is initially blocked via resistors R ₉ and R ₁₁ and, as a result, transistor T ₆ via resistors R ₁₂ and R ₁₀ .

If the transistor T _{0 is} blocked, the transistor T ₇ becomes conductive via the resistor R _n and the diode D ₂ , which in turn switches on the transistor T ₈ and thus starts the motor M _2. The transistors T ₇ and T ₈ together with the resistors i? ₁₄ to i? ₁₇ a bistable flip-flop stage which prevents the film transport _{motor M 2} from being switched off in the event of strongly fluctuating scene brightnesses.

The transistors T ₃ to T ₆ , like the two transistors T ₁ and T _{2, are} permanently connected to voltage, since they do not consume any current as long as the bridge is not detuned or is not receiving _{a supply voltage EZ 2.} By means of the switch S ₁ , both the voltage converter SpW and thus the automatic coating system are put into operation and the flip-flop circuit with the film transport motor M _{2 is connected} to voltage in preparation. The switch S ₂ enables the exposure conditions to be checked before the film starts running. Both switches S ₁ and S ₂ can also be combined to form a _{sequence switch, the function of switch S 2 being} assigned to the first contact. By operating the switch S ₄ with the switch S ₁ closed, the MOtOrM ₁ , which is used to control the diaphragm, is disconnected from the bridge. However, it is immediately connected to voltage again via the base-emitter path of the transistor T ₉ and the resistor R _{19 connected in parallel.} The motor M ₂ receives independent of the state of the transistor T ₆ via the collector of the transistor T ₉ voltage and starts up.

If the motor M ₂ is to start even when the bridge is not balanced, which z. B. is the case when recordings are still to be made in poor lighting conditions, the motor M ₂ can be put into operation by briefly pressing the switch S _3. The voltage converter SpW and thus the bridge are de-energized, as is the motor M ₁ . But that the motor M ₂ starts. The same can be achieved by the delay element built up from the components R ₂₀ , C, D ₃ , which is dimensioned so that it drives the motor M ₉ after a time that is greater than the time it takes for the "aperture" to run from a Extreme position in the other needed, puts into operation.

Claims (6)

Patent claims: 1. Circuit arrangement for the consistent switching on of an automatic exposure control and the Shutter including film transport in a motion picture camera, characterized in that that means are present which the actuation of the shutter and the film transport then start when the aperture controlled by the automatic exposure control is down to one Residual value has approached its debit position. 2. Circuit arrangement according to claim 1, characterized in that a voltage-dependent controlled switch (Rl ₁ ) is connected in parallel to the motor (3) of the automatic exposure system, the contact of which is ^ r ₁ ) in the power supply to the film drive motor (2). 3. Circuit arrangement according to claim 1, characterized in that the motor (M ₁ ) of the automatic exposure via a transistor circuit as a voltage-controlled switch is followed by a flip-flop stage (T ₇ , T ₈ , A ₁₄ to R ₁₁ ) , which Start of the film drive motor (M ₂ ) controls. 4. Circuit arrangement according to one of claims 1 to 3, characterized in that the circuit arrangement contains a component (Rl ₂ , D ₃ ) controlled via a time circuit (R ₂₀ , C) which, after actuation of the operating _{switch (S 1} ), drives the film drive motor ( 2, M ₂ ) after a time that is equal to or greater than the time required to move the diaphragms from their one extreme position to the other extreme position, applies voltage. 5. Circuit arrangement according to one of claims 1 to 3, characterized in that a switch (S ₄ ) to be actuated when fading is followed by a voltage-controlled switch (T ₉ ) which releases the voltage supply to the film transport motor (M ₂ ). 6. Circuit arrangement according to one of claims 1 to 3, characterized in that an interrupter switch (S ₃ ) is inserted into the supply circuit of the bridge, upon actuation of which the film transport motor (M ₂ ) starts up regardless of the state of the bridge. 1 sheet of drawings 809 569 / 3Φ9 7.68 © Bundesdruckerei Berlin