Motor drive apparatus for photographic camera

A motor drive apparatus comprises phase switches adapted to assume a first state upon shutter release of a camera, to cause the film advancement to be started upon receipt of an exposure completion signal from the camera in the first state and to assume a second state upon completion of the film advancement to enable succeeding shutter release. A timer circuit is adapted to start counting time upon receipt of the exposure completion signal from the camera and to release a timer signal upon completion of counting after the lapse of a predetermined period. Release apparatus is adapted to generate a release signal during the second state of the phase switches and upon release of the timer signal from the timer circuit thereby causing the shutter release of camera to be started. The motor drive apparatus can avoid the influence of variation in the film advancing period in continuous photographing and achieve an always constant actual interval.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a control apparatus for a photographic camera 
wherein a motor drive device performs the film advancement, shutter 
charging and shutter release to enable electrically driven photographing. 
2. Description of the Prior Art 
In conventional motor drive apparatus, an interval for determining the rate 
of continuous photographing is provided between the shutter release and 
the start of film advancement. In such apparatus, however, the interval 
from the completion of exposure of a frame to the start of exposure of a 
succeeding frame in continuous photographing (hereinafter called "actual 
interval") is equal to the sum of the above-mentioned interval and the 
period from the start of film advancement to the start of exposure of the 
succeeding frame. In ordinary motor drive apparatus wherein the drive 
motor is not controlled at a fixed speed, the period required for film 
advancement is subject to variation in the power supply voltage or in the 
film advancing torque, and the actual interval is significantly affected 
by the variation of the film advancing period if it occupies a major 
portion in said actual interval. For this reason an accurate actual 
interval cannot be expected in such motor drive apparatus. 
SUMMARY OF THE INVENTION 
An object of the present invention, therefore, is to provide a control 
apparatus for a photographic camera provided with a motor drive device 
eliminating the above-mentioned drawbacks and avoiding the influence of 
variation in the film advancing period in continuous photographing thereby 
allowing a constant actual interval. 
An another object of the present invention is to provide a control 
apparatus for a photographic camera provided with a motor drive device 
eliminating the above-mentioned drawbacks and allowing selection of 
various photographing modes.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Now the present invention will be explained in detail with respect to the 
preferred embodiments thereof. In the following embodiments the camera and 
the motor drive apparatus are supposed to be mutually detachable, but the 
present invention will not be limited to such particular form of 
embodiment. In FIG. 1 illustrating a first embodiment of the present 
invention, a block indicates the circuitry on the camera side. Upon 
closure of a release switch SW1 connected with the shutter button on the 
camera, an electromagnetic release device 2 actuates a shutter mechanism 3 
through a shutter time control device 4 to initiate the exposure. The 
shutter time control device 4 determines the exposure time according to 
the setting of a shutter dial 5. The camera is designed to allow selection 
of exposures, according to the setting of the shutter dial 5, for example 
automatic exposure by an electronic shutter followed diaphragm opening, 
manual bulb exposure or manual bulb exposure or manually selected exposure 
time. An exposure completion switch SW2 is turned OFF upon closure of the 
shutter and thus completion of exposure to generate an exposure completion 
signal and is turned ON just before the completion of shutter charging. A 
first sequence selecting switch SW10 on the camera side is adapted to be 
turned ON or OFF in combination with a selecting switch SW6 and a second 
sequence selecting switch SW9 of the motor drive apparatus to enable 
various operating modes in combination with the motor drive apparatus as 
will be explained later. 
The first sequence selecting switch SW10 is turned ON when an automatic 
exposure followed diaphragm opening or a manually selected slow shutter 
speed (for example an exposure of 1/60 sec. or is selected by the shutter 
dial 5, and is turned OFF when a manually selected fast shutter speed (for 
example an exposure of 1/25 sec. or a bulb exposure is selected. 
The electric connections between the camera and the motor drive apparatus 
are achieved through the contacts T1 to T5 and through the contact between 
the camera body and the body of motor drive apparatus. The rotation of a 
motor M, which is controlled by means of a switch SW3, is transmitted to a 
known drive mechanism 6, which in turn controls shutter charging and film 
advancing mechanisms (not shown) of the camera through a film winding link 
mechanism 7. The switch SW3 cooperates with a relay coil L and assumes the 
position b or a respectively when said relay coil L is energized or not. A 
trigger switch SW4 is turned ON upon actuation of a trigger button (not 
shown) of the motor drive apparatus to cause a predetermined photographing 
operation of the apparatus to be initiated. A resistor R1 and a Zener 
diode D1 connected in series between the terminals of the power source 
upon closure of the trigger switch SW4 constitute a voltage stabilizing 
circuit for the timer circuit which will be explained later. 
A capacitor C1, resistors R4 and R5 and a transistor Q2 constitute a start 
circuit wherein the transistor Q2 is rendered conductive to shortcircuit a 
resistor R6 only during an instant of the closure of the trigger switch 
SW4. Also a timer circuit is composed of a capacitor C2, resistors R2, R3, 
R6, R7 and R8, transistors Q1 and Q3. 
The resistor R6 is variable to adjust the required timer period. Upon lapse 
of a predetermined timer period, a circuit interconnection from the timer 
capacitor C2 to the base of the transistor Q1 causes that element to be 
rendered conductive to generate a timer signal. A phase switch SW5 which 
is controlled by the drive mechanism 6 is changed over to the terminal d 
upon completion of shutter release and to the terminal e upon completion 
of film advancement. A selecting switch SW6 is provided to select 
single-frame photographing or continuous photographing at the position s 
or c, respectively. A transistor Q6 controls the current through the relay 
coil L when the phase switch SW5 is in the terminal position e. 
Transistors Q8, Q7, and resistors and a diode connected thereto constitute 
a circuit for stopping the function of the motor drive apparatus. When the 
camera 1 is in a state allowing photograph taking, there is provided at 
the terminal T1 a potential or a normal photographing signal, which can 
shift the transistor Q7 to conductive state. Therefore, when the camera 1 
is in a state allowing photographing operation, the transistor Q7 is made 
conductive by means of the potential to shift the transistor Q8 to 
non-conductive state. As the result the transistor Q6 is controlled 
according to the ON or OFF state of the transistor Q1 to allow 
photographing by means of the motor drive apparatus. When the camera 1 is 
in a state not allowing the photographing operation, for example if 
photographing by automatic exposure mechanism is not feasible, if the 
power switch on the camera is not turned on, if the power voltage on the 
camera is outside a predetermined range or if frames of a predetermined 
number are already exposed, there will not be provided at the terminal T1 
a potential allowing the transistor Q7 to be turned on, which therefore 
remains in non-conductive state even when the trigger switch SW4 is 
closed. Consequently the transistor Q8 is in a conductive state to retain 
the transistor Q6 in non-conductive state thereby suspending the function 
of the motor drive apparatus. A switch SW7 connected in parallel with the 
release switch SW1 of the camera through the terminals T2 and T3 and a 
switch SW8 connected in series with the exposure completion switch SW2 
through the terminal T4 are turned on and off in approximate 
synchronization. These switches SW7, SW8 are turned ON by the drive 
mechanism 6 upon closure of the trigger switch SW4 and subsequent rotation 
of motor M, and turned OFF at the film advancement by the motor M through 
the drive mechanism 6 after the completion of exposure. Upon closure of 
the switch SW7 the electromagnetic release device 2 causes the exposure to 
be initiated. A second sequence selecting switch SW9 provided on the motor 
drive apparatus and connected in parallel with said first sequence 
selecting switch SW10 through the terminal T5 is turned on or off 
according to the selected operation mode. The details of the circuit shown 
in FIG. 1 and explained in the foregoing will be further clarified through 
the explanation of function thereof. 
Now there will be given an explanation on the function of the present 
embodiment. FIG. 1 illustrates a state wherein the function of camera and 
motor drive apparatus is suspended after a film advancement. 
In a first operating mode the selecting switch SW6 is positioned at the 
terminal c, representing the continuous photographing mode selected by the 
motor drive apparatus, and the second sequence selecting switch SW9 is in 
ON state allowing the transmission of the signal from the exposure 
completion switch SW2 to the motor drive apparatus. On the camera any 
photographing mode other than bulb exposure may be arbitrarily selected. 
In this state a normal photographing signal is provided to the terminal T1 
since the camera is in a state allowing photographing operation. Now, upon 
closing the trigger switch SW4 to start the photographing, the potential 
of the connecting point between the condenser C1 and resistor R4 becomes 
instantaneously equal to the source voltage to shift the transistor Q2 to 
conductive state for an instant, thereby shortcircuiting the resistor R6. 
Also the base of transistor Q1 assumes same potential as that of the 
connecting point between the Zener diode D1 and resistor R1 to render the 
transistor Q1 instantaneously conductive regardless of the resistor R6, 
thereby shifting the transistor Q6 to conductive state. In this state the 
phase switch SW5 is in the terminal position e because the shutter release 
has not yet occurred. Consequently a current is supplied through the phase 
switch SW5 to the relay coil L to change over the switch SW3 to the 
terminal b, thus supplying current to the motor M. The motor rotation, 
through the drive mechanism 6, closes the switches SW7 and SW8 to perform 
the shutter release of the camera 1. Simultaneously the phase switch SW5 
is changed over from the terminal e to d, whereby the transistor Q5 is 
maintained in OFF state until the exposure completion switch SW2 is turned 
OFF, thus interrupting the current in the relay coil L. As the result, the 
switch SW3 returns to the position a, thus rapidly stopping the motor M by 
electromagnetic braking. Also, upon turning on of the switch SW8 the 
transistor Q3 is turned on through said switch SW8, exposure completion 
switch SW2 and second sequence selecting switch SW9 to discharge the 
capacitor C1, thereby shifting the transistor Q1 to non-conductive state 
and resetting the timer circuit. Subsequently, upon completion of exposure 
of the camera 1, the exposure completion switch SW2 is turned off to shift 
the transistor Q5 to conductive state, thus allowing current supply to the 
relay coil L. As the result the switch SW3 is changed over the terminal 
position b to initiate the rotation of motor M for film advancement. In 
this state since the transistor Q2 is in OFF state and also since the 
transistor Q3 is also in OFF state due to the turning off of the exposure 
completion switch SW2, the capacitor C2 initiates charging through the 
resistor R6, thus starting the time counting function of the timer 
circuit. The rotation of motor M is transmitted, through the drive 
mechanism 6 and winding link mechanism 7, to the shutter charging and film 
advancing mechanisms (not shown) of the camera to perform shutter charging 
and film advancement. Also the switches SW7 and SW8 are turned OFF before 
the shutter charging and turning on of the exposure completion switch SW2 
by the drive mechanism 6. Upon completion of the film advancement the 
phase switch SW5 is changed over from the terminal position d to e. The 
length of the time period from the turning OFF of the transistor Q3 at the 
completion of exposure (when the switch SW2 is turned OFF) to the turning 
ON of the transistor Q1 by the charging of capacitor C1 through the 
resistor R6 can be arbitrarily selected by the magnitude of the resistor 
R6, and such period is selected at a value greater than the maximum period 
required for film advancement, namely the film advancing period required 
at the lowest voltage in the usable power voltage range (for example ca. 
0.3 sec.). In such state, if the trigger switch SW4 continues to be 
actuated after the phase switch SW5 is changed over from the terminal 
position d to e, the transistor Q6 remains in OFF state until the 
transistor Q1 is turned ON, and the relay coil L is therefore not 
energized to cause the changeover of the switch SW3 to the position a, 
thus stopping the motor M by electromagnetic braking. Subsequently, 
shutter release is attained by means of the invention as follows: a 
release circuit, including transistor Q1, having its emitter coupled to 
the voltage divider R2, R3, and a transistor Q6, is energized, wherein the 
transistor Q1 is turned ON, and also the transistor Q6 is turned ON upon 
generation of a timer signal from the timer circuit. The transistor Q6 
generates a release signal to energize the relay coil L thereby causing 
the rotation of motor M and closing the switch SW7 through the drive 
mechanism 6. Thus the camera shutter is released again. The 
above-explained function is repeated by the motor drive apparatus as long 
as the trigger switch SW4 is actuated, thereby achieving continuous 
photographing. Upon opening of said trigger switch SW4 the function is 
terminated at the state after the film advancement shown in FIG. 1. The 
function in the above-mentioned first operation mode is illustrated in the 
time chart of FIG. 2. 
In FIG. 2 illustrating functions of various components versus time, t1 
represents the time of start of function of the motor drive apparatus upon 
closure of the trigger switch SW4, t2 the time of start of release of 
camera shutter, t3 the time of exposure completion and start of film 
advancement, t4 the time of completion of film advancement, and t5 the 
time of generation of timer signal or start of succeeding shutter release. 
Thus the actual interval or the length of period from the completion of an 
exposure to the start of next shutter release is solely determined by the 
timer circuit and is not affected by the period required for film 
advancement which is subject to the variation of source voltage, as long 
as the timer period is selected to be longer than the maximum period 
required for film advancement. 
Now there will be given an explanation of a case wherein the selecting 
switch SW6 is in the terminal position c and the second sequence selecting 
switch SW9 is in the OFF position. In this state, the function of the 
motor drive apparatus is dependent on the photographing mode selected on 
the camera 1. In case an automatic exposure or a manually selected slow 
shutter speed (for example and exposure of 1/60 sec. or slower) is 
selected by the shutter dial 5, the first sequence selecting switch SW10 
is positioned in the ON state, and the function of the motor drive 
apparatus is same as that in the aforementioned first operating mode 
wherein the second sequence selecting switch SW9 is in the ON position. On 
the other hand, a second operating mode is conducted when a high shutter 
speed (for example an exposure of 1/125 sec. or faster) is manually 
selected by means of the shutter dial 5. In this mode the signal of 
exposure completion switch SW2 is not transmitted to the motor drive 
apparatus since the first sequence selecting switch SW10 is in the OFF 
position. Upon closure of the trigger switch SW4, the transistor Q2 is 
rendered conductive as explained before to apply a bias voltage to the 
base of transistor Q1 which is thus rendered instantly conductive thereby 
further shifting the transistor Q6 to the conductive state and causing the 
rotation of motor M. As the result the camera shutter is released and the 
phase switch SW5 is changed over from the terminal e to d. In the 
above-explained first operating mode, since the second sequence selecting 
switch SW9 is in the ON position, the ON/OFF signal of the exposure 
completion switch SW2 in the state is transmitted through the switch SW8 
to the transistor Q5 thereby holding the transistor Q5 in the 
non-conductive state and arresting the rotation of motor M until the 
exposure is completed. However, in the present second operating mode 
wherein the first and second sequence selecting switches SW9, SW10 are 
both in the OFF position, the ON signal from the exposure completion 
switch SW2 is not transmitted to the transistor Q5. Consequently the 
transistor Q5 is always in the conductive state while the phase switch SW5 
is in the terminal position d, and thus the motor M continues to rotate 
after the phase switch SW5 is changed over from the terminal position e to 
d. Thus, in this mode, the motor drive apparatus intends to start the film 
advancement simultaneously with the release of camera shutter. There is 
however provided a certain delay time from the shutter release to the 
start of actual film advancement by the drive mechanism 6 through the 
winding link mechanism 7 due to the presence of a certain play provided in 
the stroke of said drive mechanism 6 and of the film winding mechanism 
(not shown) in the camera 1. The delay time, being dependent on the 
revolution of motor M, is minimum when the power source voltage of the 
motor drive apparatus is maximum within the usable range. The duration 
from the shutter release to the completion of exposure of the 
above-mentioned manually selected high shutter speed (for example an 
exposure of 1/125 sec. or shorter) of the camera 1 is selected so as to be 
shorter than the minimum delay time. Consequently, even though the motor M 
continues to rotate after the shutter release, the exposure is completed 
before the actual start of film advancement, thereby preventing image 
streaking resulting from eventual film movement during the exposure. The 
phase switch SW5 is changed over from the terminal d to e upon completion 
of the exposure and of the film advancement. On the other hand, since the 
first and second sequence selecting switches SW9, SW10 are both in the OFF 
position, the transistor Q3 remains in the non-conductive state and the 
capacitor C1 is therefore not discharged. Thus, the transistor Q1, after 
being shifted to the conductive state upon closure of the trigger switch 
SW4, remains in said state as long as the trigger switch SW4 remains 
thereafter in the closed state, whereby the relay coil L continues to be 
energized and the motor M continues to rotate even after the phase switch 
SW5 is shifted to the terminal position e. Consequently the motor drive 
apparatus again releases the camera shutter and thereafter repeats the 
above-explained functions to perform continuous photographing until the 
trigger switch SW4 is turned OFF. In this manner the second operating mode 
achieves continuous photographing by continuous rotation of motor M for a 
limited range of high shutter speeds, enabling high-speed continuous 
photographing though the number of frames exposed per unit time is 
dependent on the power source voltage. 
The functions of the above-explained second operaing mode is shown in the 
time chart of FIG. 4, wherein t1 represents the time of closure of trigger 
switch SW4, t2 the time of start of shutter release, t3 the time of 
completion of exposure, and t4 the time of completion of film advancement. 
Now there will be explained a third operating mode wherein the selecting 
switch SW6 is in the position s and the second sequence selecting switch 
SW9 is in the ON position, representing a single-frame photographing mode. 
In this state the ON, OFF signal of the exposure completion switch SW2 is 
always transmitted to the motor drive apparatus because of said second 
sequence selecting switch SW9 in the ON position. In this state any 
photographing mode other than bulb exposure may be selected on the camera 
1. The function of the third operating mode is as follows. 
Upon closure of the trigger switch SW4, the transistor Q1 is instantly 
rendered conductive by the transistor Q2 in the manner explained before to 
shift the transistor Q6 to the conductive state, thereby initiating the 
rotation of motor M. Thus the drive mechanism 6 releases the camera 
shutter and shifts the phase switch SW5 from the terminal e to d. The 
transistor Q5 is then turned off as the base thereof is connected to the 
common terminal through the diode D3, selecting switch SW6 and the trigger 
switch SW4. Also the transistor Q5 is turned off when the exposure 
completion switch SW2 is in the ON state as the base of said transistor is 
connected to the negative terminal of the power source through the second 
sequence selecting switch SW9, the switch SW8 and the exposure completion 
switch SW2. Consequently the transistor Q5 is maintained in the 
non-conductive state unless the trigger switch SW4 and the exposure 
completion switch SW2 are both turned OFF. Thus upon shifting of the phase 
switch SW5 to the terminal position d, the relay coil L ceases to be 
energized and the motor M is stopped if the transistor Q5 is in the OFF 
state. The transistor Q5 is shifted to the conductive state when the 
trigger switch SW4 is turned off before the completion of exposure because 
the exposure completion switch SW2 is turned OFF, or when the trigger 
switch SW4 is turned off after the completion of exposure, thus causing 
the motor M to rotate and the film to advance. Upon completion of film 
advancement the phase switch SW5 is changed over to the terminal e to 
terminate the rotation of motor M as the trigger switch SW4 is then 
already in the OFF state. Thus, upon reclosure of the trigger switch SW4, 
the above-explained functions are repeated to perform single-frame 
photographing. In this manner this third operating mode securely performed 
single-frame photographing regardless of the timing of turning OFF of the 
trigger switch SW4. 
The functions of the third operating mode are illustrated in the time chart 
of FIG. 3, wherein t1-t5 represent the functions in case the trigger 
switch SW4 is turned OFF appropriately after the completion of exposure, 
t1 representing the time of closure of trigger switch SW4, t2 the time of 
start of shutter release, t3 the time of completion of exposure, t4 the 
time of opening of trigger switch SW4, and t5 the time of completion of 
film advancement; while t6-t10 represent the functions in case the trigger 
switch SW4 is turned OFF before the completion of exposure, t6 
representing the time of the closure of trigger switch SW4, t7 the time of 
shutter release, t8 the time of opening of trigger switch SW4, t9 the time 
of completion of exposure, and t10 the time of completion of film 
advancement. 
Now there will be given an explanation on a fourth operating mode wherein 
the selecting switch SW6 of the motor drive apparatus is positioned at the 
terminal s and the second sequence selecting switch SW9 is in the OFF 
position. On the camera the bulb exposure is selected so that the first 
sequence selecting switch SW10 is, as explained before, in the OFF 
position. In this operating mode the camera shutter is opened to perform 
exposure during the ON state of trigger switch SW4, of which turning OFF 
causes the shutter to be closed to complete the exposure and the film to 
be advanced. 
In this mode, upon closure of the trigger switch SW4, the transistor Q6 is 
instantly rendered conductive as explained before to cause the motor M to 
rotate, thereby releasing the camera shutter and shifting the phase switch 
SW5 from one terminal position e to d. In this state the transistor Q5 is 
in the OFF state as the base thereof is connected to the negative pole of 
the power supply through the diode D3, selecting switch SW6 and trigger 
switch SW4. Consequently the motor M stops upon turning ON of the switch 
SW7, i.e. after the shutter release. As the bulb exposure is selected on 
the camera 1, the shutter remains open while the switch SW7 is in the ON 
state. The closing of the shutter is performed by opening the trigger 
switch SW4. The ON signal of exposure completion switch SW2 is not 
transmitted to the motor drive apparatus as the first and second sequence 
selecting switches SW9, SW10 are positioned in the OFF state, so that the 
opening of trigger switch SW4 shifts the transistor Q5 to the conductive 
state thereby causing the rotation of motor M, which however initiates the 
advancement of film after the closing of shutter due to a certain play 
provided in the stroke of the drive mechanism 6 and the film winding 
mechanism (not shown) of camera 1 as explained in the foregoing, thereby 
preventing the streaking of photographed image. Upon completion of film 
advancement the phase switch SW5 is changed over to the terminal e whereby 
the motor stops as the trigger switch SW4 is open in this state. Upon 
reclosure of the trigger switch SW4 the above-explained functions are 
repeated to open the shutter while the trigger switch SW4 is in the ON 
state and to close the shutter upon opening of the switch and thereafter 
perform the film advancement. 
The functions of this fourth operating mode are illustrated in the time 
chart of FIG. 5 wherein t1 represents the time of closure of trigger 
switch SW4, t2 the time of start of shutter release, t3 the time of 
opening the trigger switch SW4, t4 the time of completion of exposure, and 
t5 the time of completion of film advancement. 
In a fifth operating mode the selecting switch SW6 of the motor drive 
apparatus may be positioned either at the position s or c, but the second 
sequence selecting switch SW9 is positioned in the ON state. The bulb 
photographing mode is selected on the camera 1 so that the first sequence 
selecting switch SW10 is in the OFF state. In this operating mode the 
camera shutter is opened to perform exposure upon closure of the trigger 
switch SW4, remains open after the opening of trigger switch SW4 and is 
closed by turning OFF of the second sequence selecting switch SW9 thereby 
achieving so-called time exposure, followed by film advancement. 
Upon closure of the trigger switch SW4 the motor M is caused to rotate as 
explained in the foregoing thereby releasing the camera shutter and 
shifting the phase switch SW5 from the terminal e to d, whereupon the 
transistor Q5 is rendered non-conductive as the base thereof is connected 
to the negative pole of the power source through the switch SW8, exposure 
completion switch SW2 and second sequence selecting switch SW9, thus 
stopping the motor M in the ON state of switch SW7, i.e. after shutter 
release. Since bulb exposure is selected on the camera 1, the shutter 
remains open as long as the switch SW7 is in the ON state. In this state 
the shutter is maintained open even if the trigger switch SW4 is turned 
OFF since the transistor Q5 is maintained in the OFF state due to the ON 
state of the exposure completion switch SW2, thus maintaining the motor M 
in standstill. The shutter closing is achieved by turning OFF of the 
second sequence selecting switch SW9, whereby the transistor Q5 is 
rendered conductive to cause the rotation of motor M which opens the 
switches SW7, SW8 to close the shutter and also performs the film 
advancement. Upon completion of film advancement the phase switch SW5 is 
changed over from the terminal d to e to stop the motor M as the trigger 
switch SW4 is already in the OFF state. For closing the shutter the second 
sequence selecting switch SW9 needs to be opened only for a short period 
required for the steps of rotation of motor M to open the switches SW7 and 
SW8, shutter closing and opening of the exposure completion switch SW2, 
and may be thereafter reclosed to prepare for the time exposure of the 
succeeding frame. Upon reclosure of the trigger switch SW4 the 
above-explained functions are repeated whereby the shutter is maintained 
open even after the trigger switch SW4 is opened and is closed upon 
turning OFF of the second sequence selecting switch to achieve the time 
exposure followed by film advancement. In this manner it is no longer 
necessary, in case of an exposure of an extended period, the maintain the 
trigger switch SW4 in the ON state throughout the exposure period as 
required in the fourth operating mode. 
In the following there will be explained another embodiment of the present 
invention illustrated in FIG. 6, in which the same components as those in 
FIG. 1 are given the same numerals and are omitted from the following 
explanation. 
The embodiment shown in FIG. 6 is different from that in FIG. 1 in that, 
whereas the start circuit in FIG. 1 is structured to render the transistor 
Q2 conductive only for an instant upon closure of the trigger switch SW4 
thereby immediately rendering the transistor Q1 conductive without any 
delay determined by the timer circuit, the start circuit in FIG. 6 is 
structured such that a capacitor C2 is charged while the trigger switch 
SW4 is open and renders the transistor Q1 conductive immediately upon 
closure of the trigger switch SW4. 
Referring to FIG. 6, the capacitor C2 is charged through a diode D10 and a 
resistor R10 when the trigger switch SW4 is in the OFF state, or the motor 
drive apparatus is not functioning. A diode D11 for blocking reverse 
current is provided to block unnecessary current supply to the circuit of 
resistor R10 and diode D10 through the resistors R1, R2 and R3 or through 
the resistor R2 and base of transistor Q1, and also to compensate the 
fluctuation, of the timer period resulting from temperature-dependent 
variation of base-emitter voltage of the transistor Q1. The transistor 
Q10, being a PNP type, has no current through the base and collector 
thereof to the resistor R10 when the trigger switch SW4 is in the OFF 
state, and does not involve, therefore, unnecessary current consumption 
once the condenser C2 is charged during the stand-by period wherein the 
trigger switch SW4 is maintained open. 
Upon closure of the trigger switch SW4, a Zener potential generated across 
the Zener diode D1 provide a forward bias to the transistor Q10 through a 
resistor connected to the base thereof thereby rendering the transistor 
conductive. Thus the diode D10, becoming biased backwards with the cathode 
thereof assuming a potential substantially equal to that of the positive 
pole of power source, shows no current therethrough, and the function of 
timer circuit thereafter is not affected by the capacitor C2. The 
capacitor C2, being charged to a potential higher than the activating 
level of the transistor Q1, renders, upon closure of the trigger switch 
SW4, the transistor Q1 conductive which in turn renders the transistor Q6 
conductive to energize the relay coil L and to cause the rotation of motor 
M whereby the drive mechanism 6 releases the camera shutter. The turning 
OFF of the trigger switch SW4 renders the transistor Q10 non-conductive 
whereby the capacitor C2 is charged again through the diode D10 and 
resistor R10 to prepare for the next closure of the trigger switch SW4. 
Explanation of the operating modes will be omitted since the same 
operating modes as in the first embodiment can be achieved by suitably 
positioning the selecting switch SW6 and the first and second sequence 
selecting switches SW9, SW10 in the same manner as explained with respect 
to the first embodiment. 
FIG. 7 shows a third embodiment of the present invention wherein a 
transistor Q20 is designed to provide the start signal upon closure of the 
trigger switch SW4, and the turning ON of the transistor renders the 
transistor Q6 conductive to cause the rotation of motor M thereby 
releasing the camera shutter. It is now assumed that the switches in the 
motor drive apparatus are positioned to perform the first operating mode 
as illustrated in FIG. 7. Upon closure of the trigger switch SW4 in this 
state, the transistor Q20 is rendered conductive by a charging current of 
a capacitor C20 through a resistor R21. As the result the transistor Q6 is 
rendered conductive to cause the rotation of motor M, whereby the switch 
SW7 is turned on to release the camera shutter and changing over the phase 
switch SW5 from the terminal e to d. The duration the conductive state of 
the transistor Q20 is substantially determined by the time constant of the 
capacitor Q20 and resistor R21 and is selected longer than a period 
required for the steps of closure of trigger switch SW4, shutter release 
by the motor rotation and changing over of the phase switch SW5 from the 
terminal e to d. Upon the changing over of the capacitor C20 is charged 
through the relay coil L and diode D20. Because of a sufficiently low 
resistance in the relay coil L, the capacitor C20 is charged within a 
short period to a level sufficient to shut off the transistor Q20 which is 
thereby rendered non-conductive. The transistor Q20 remains in the 
non-conductive state since there is no charging current in the capacitor 
C20 as long as the trigger switch SW4 is in the ON state. Upon the opening 
of the trigger switch SW4, the capacitor C20 is rapidly discharged through 
a discharge accelerating diode D21 and resistors R2, R3 and R1 to prepare 
for the reclosure of the trigger switch SW4. In the second operating mode 
wherein the selecting switch SW6 is positioned at the terminal c, the 
second sequence selecting switch SW9 is in the OFF position, the camera 1 
is manually set for a high shutter speed and the first sequence selecting 
switch SW10 is in the OFF state as explained with respect to the first 
embodiment, the closure of trigger switch SW4 initiates the rotation of 
motor M whereby the shutter release is conducted and the phase switch SW5 
is simultaneously changed from the terminal e to d. However the motor M 
continues to rotate since the transistor Q5 is not rendered 
non-conductive, to close the shutter after a predetermined period and 
conduct film advancement, upon the completion of which the phase switch 
SW5 is changed over from the terminal d to e. At this point the transistor 
Q6 should already be in conductive state for the following reason. In the 
circuit of FIG. 1, the capacitor C2 is instantaneously charged above a 
level rendering the transistor Q1 conductive upon closure of the trigger 
switch SW4, and is not discharged in the second operating mode to 
continuously maintain the transistor Q1 in the conductive state. On the 
other hand, in the circuit of FIG. 7, as the charging of capacitor C2 is 
initiated at the closure of trigger switch SW4, high-speed continuous 
photographing cannot be achieved unless the capacitor C2 is charged to the 
level enough for rendering the transistor Q1 conductive when the phase 
switch SW5 is changed over from the terminal d to e as otherwise the 
transistors Q1 and Q6 cannot be turned ON. For this reason, the time 
constant of the timer circuit is selected by means of the variable 
resistor R6 to satisfy the above-mentioned conditions. The functions in 
other operating modes are not explained in detail because they are 
obtained by appropriately positioning the selecting switch SW6, and the 
first and second sequence selecting switches SW9 and SW10 as explained 
with respect to FIG. 1. 
FIG. 8 shows a fourth embodiment of the present invention which differs 
from the foregoing embodiments in that a bistable circuit for starting the 
rotation of motor M for the shutter release upon closure of the trigger 
switch SW4 without the delay by the timer circuit, and in that the phase 
switch SW51 is composed of a simple on-off switch instead of change-over 
switch between the terminals e and d. The switch SW51 is turned ON 
simultaneously with the closure of the switch SW7 upon rotation of motor M 
and is turned OFF upon completion of the film advancement. The bistable 
circuit which functions as the start circuit is composed of transistors 
Q31, Q32, and resistors R32, R33. A capacitor C30 functions for preventing 
the erraneous operation resulting from noise. 
In the first operating mode, upon closure of the trigger switch SW4, as the 
transistors Q31 and Q32 are maintained in OFF state, the transistor Q6 is 
biased conductive through the resistor R30 and diode D30 to energize the 
relay coil L, thereby causing the rotation of motor M to effect the 
shutter release and to close the phase switch SW51. Upon the turning ON of 
the phase switch SW51, the bistable circuit composed of the transistors, 
Q31, Q32 applies a bias through the phase switch SW51 and diode D32 to the 
transistor Q32 to render the transistor, conductive, whereby the 
transistor Q32 and Q31 are maintained in conductive state by means of 
positive feedback action as long as the trigger switch SW4 is in closed 
state. When the transistor Q32 assumes conductive state, the transistor 
Q6, of which bias is clamped by the diode D33, is not rendered conductive 
by the bias caused by the resistor R30. Also as the transistor Q8 is 
biased conductive through the phase switch SW51, resistor R35 and diode 
D31 when the switch SW51 is closed, the current to the relay coil L is 
solely governed by the on-off state of transistor Q5. Thus, as the 
transistor Q6 can be shut off regardless of the state of transistor Q1, 
the motor M stops when the transistor Q5 is shut off. The motor M starts 
rotation upon the turning on of the transistor Q5, and, upon completion of 
the film advancement, the phase switch SW51 is opened to shut off the 
transistor Q5. If the trigger switch SW4 is maintained closed, the 
transistor Q8 is shut off whereby the transistor Q6 is truned on 
simultaneously with the turning on of the transistor Q1 to perform the 
shutter release for the succeeding frame. Upon the opening of the trigger 
switch SW4, the transistors Q31, Q32 are reset of OFF state. The 
above-explained steps are repeated upon reclosure of the trigger switch 
SW4. In the second operating mode, the resistor R6 of the timer circuit, 
as explained in connection with the third operating mode of FIG. 7, should 
be adjusted to a value that will render the transistor Q1 conductive upon 
closure of the trigger switch SW4 before the phase switch SW51 is turned 
off. The functions of other operating modes are not explained in detail as 
they are achieved by appropriately positioning the selecting switch SW6 
and the first and second sequence selecting switches SW9, SW10 as 
explained in connection with the circuit of FIG. 1. 
FIG. 9 shows a fifth embodiment of the present invention wherein the phase 
switch SW51 is structured, as in FIG. 8, to be closed simultaneously with 
the closure of switch SW7 upon rotation of motor M and to be opened upon 
completion of the film advancement. The transistors Q41, Q42, Q43, Q44, 
resistors R37, R38, capacitor C22 and diodes D32, D33 constitute a circuit 
for current feeding and electromagnetic braking for motor M, which circuit 
is composed by the relay coil L and switch SW3 in other embodiments. Upon 
the turning on of the transistor Q41, the transistor Q42 is turned on 
through the resistor R37 to supply current to the motor M and also to 
discharge the capacitor C22 through the diode D33 and transistor Q42. Also 
since the transistor Q41 is in conductive state, the transistors Q43 and 
Q44 are clamped in non-conductive state by means of the diode D32. When 
the transistor Q41 is turned off, the transistor Q42 is also shut off to 
interrupt the current to the motor M and also render the transistors Q43, 
Q44 conductive by the charging current for the capacitor C22 through the 
resistor R38. Thus the motor M is short-circuited through the transistor 
Q43, and is rapidly stopped by electromagnetic braking. The transistors 
Q43, Q44 are shifted to the non-conductive state upon completion of the 
charging of capacitor C22. The timer circuit and start circuit are 
composed of resistors R2, R3, R7, R8, R61, transistors Q1, Q21, Q31, and 
capacitor C21. While in the embodiment of FIG. 1 the transistor Q1 in the 
timer circuit is rendered conductive upon the charging of the capacitor 
C2, the transistor Q1 in the present embodiment is rendered conductive 
upon discharge of the capacitor C21. The function of the present 
embodiment is as follows. 
Upon closure of the trigger switch SW4, as the capacitor C21 being in the 
discharged state, the transistor Q1 is shifted to conductive state to 
render the transistor Q6 conductive, whereby the transistor Q41 is 
rendered conductive through resistor R36 to cause the motor M to rotate. 
The transistor Q21, being inversely biased, remains in non-conductive 
state. The rotation of motor M turns on the switch SW7 to conduct shutter 
release and also closes the phase switch SW51. Thereupon the transistor 
Q8, being biased through the phase switch SW51, diode D31 and resistor 
R35, is shifted to the conductive state to render the transistor Q6 
non-conductive. Thus the transistor Q41 is turned on according to the 
state of transistor Q5. In case of an operating mode wherein the 
transistor Q5 is non-conductive, for example the first operating mode, the 
transistor Q5 is maintained non-conductive while the transistor Q31 is 
maintained conductive until the completion of the exposure. When the 
transistor Q5 is shut off the transistor Q41 is likewise shut off to apply 
elechromagnetic braking to the motor M to hold the same in standstill. 
Also as the transistor Q31 is in conductive state until the completion of 
exposure, the capacitor C21 is immediately charged to a potential 
substantially equal to the voltage across the Zener diode D1 thereby 
shutting off the transistor Q1. Upon completion of the exposure the 
exposure completion switc SW2 is opened to render the transistor Q5 
conductive thereby causing the rotation of motor M to effect the film 
advancement and shutting off the transistor Q31 to discharge the capacitor 
C21 through the resistor R61. Upon completion of the film advancement the 
phase switch SW51 is opened and the transistor Q5 is shut off. If the 
trigger switch SW4 is maintained in closed state, the transistor Q8 is 
shut off, and the transistor Q6 is rendered conductive since the 
transistor Q1 is in conductive state. When the voltage across the 
capacitor C21, being discharged through the resistor R61, is lowered to 
the level rendering the transistor Q1 conductive, the transistor Q1 
therefore becomes conductive to render the transistor Q6 conductive 
thereby effecting shutter release for the succeeding frame. Upon the 
opening of the trigger switch SW4, the film advancement is completed and 
the phase switch SW51 is opened to stop the motor M and to apply a bias to 
the transistor Q21 by the retentive charge in the capacitor C21 applied 
through the resistors R2, R3. Thus the transistor Q21 is rendered 
conductive whereby the capacitor C21 is immediately discharged below the 
ON level for the transistor Q1 thereby preparing said transistor Q1 for 
next function for succeeding photograph taking upon reclosure of the 
trigger switch SW4. Other operating modes will not be explained in detail 
as they can be achieved by appropriately positioning the selecting switch 
SW6, and the first and second sequence selecting switches SW9, SW10 as 
explained in connection with FIG. 1. 
In the foregoing explanation of FIGS. 1, 6, 7, 8 and 9 the selecting switch 
SW6 and the second sequence selecting switch SW9 are structured to be 
individually operable for achieving various operating modes, but it is 
also possible to provide the motor drive apparatus with a suitable member 
for selecting the operating modes, the member being structured, when 
pointing at a particular operating mode, to correspondingly make 
connections of the selecting switch SW6 and the second sequence selecting 
switch SW9. Also in the foregoing explanation, the shutter release of the 
camera 1 is electrically connected with the motor drive apparatus, but 
such connection can also be achieved by mechanical means for example a 
shutter release pin, and in such case it will be evident that the 
functions in the foregoing embodiments can be achieved if the shutter 
release pin is structured to close the switch SW8 when it is in a position 
to release the camera shutter and to open the switch SW8 when it is in a 
position not to release the shutter. 
As explained in the foregoing the present invention allows, in the first 
operating mode thereof, to exactly determine the actual interval from the 
completion of exposure to the shutter release for the succeeding frame 
solely by the timer period and without the effect of variation in the film 
advancing time which is dependent on the power source voltage and load, as 
long as the timer period is selected to be greater than the period from 
the completion of exposure to film advancement. Also the present invention 
provides a motor drive apparatus allowing the selection of various 
operating modes.