U.S. patent number RE29,599 [Application Number 05/698,384] was granted by the patent office on 1978-03-28 for control circuit for photographic apparatus.
This patent grant is currently assigned to Honeywell Inc.. Invention is credited to Francis T. Ogawa.
United States Patent |
RE29,599 |
Ogawa |
March 28, 1978 |
**Please see images for:
( Reexamination Certificate ) ** |
Control circuit for photographic apparatus
Abstract
An automatic photographic camera, which features automatic
focusing, automatic exposure control, automatic flash operation and
automatic film advance and shutter cocking, includes an electronic
control circuit. The electronic control circuit includes a binary
logic circuit which is responsive to a number of parametric signals
to effect a control of the timing and actuation of the several
automatic functions of the camera.
Inventors: |
Ogawa; Francis T. (Lakewood,
CO) |
Assignee: |
Honeywell Inc. (Minneapolis,
MN)
|
Family
ID: |
23477830 |
Appl.
No.: |
05/698,384 |
Filed: |
June 21, 1976 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
374691 |
Jun 28, 1973 |
03917395 |
Nov 4, 1975 |
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Current U.S.
Class: |
396/48; 396/165;
396/166 |
Current CPC
Class: |
G03B
7/17 (20150115); G03B 7/003 (20130101); G03B
7/093 (20130101) |
Current International
Class: |
G03B
7/00 (20060101); G03B 7/00 (20060101); G03B
7/091 (20060101); G03B 7/091 (20060101); G03B
7/093 (20060101); G03B 7/093 (20060101); G03B
7/16 (20060101); G03B 7/16 (20060101); G03B
007/08 (); G03B 003/00 (); G03B 015/05 () |
Field of
Search: |
;354/23D,25,32,33,34,50,51,6R,145,149,195 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hix; L. T.
Assistant Examiner: Gellner; M. L.
Attorney, Agent or Firm: Hanson; H. L. Ungemach; C. J.
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. In an automatic photographic camera featuring a plurality of
automatic functions, a control system for controlling the sequence
and actuation of said automatic functions, said control system
comprising:
means for producing a plurality of parametric signals
representative of parameters related to said automatic
functions,
a binary logic control circuit responsive to said parametric
signals for producing a plurality of control signals,
said binary logic control circuit including means for establishing
the selection and sequence of the actuation of said automatic
functions,
means responsive to said control signals to effect the actuation of
said automatic functions,
said control system including an automatic exposure control means
for controlling the operation of the shutter of said camera,
said control means including an integrating light sensing
means,
voltage reference means,
signal comparator means connected to said light sensing means and
to said voltage reference means for producing one of said
parametric signals as a function of the comparison of the outputs
of said voltage reference means and said light sensing means,
said binary logic control circuit including gating means responsive
to said one parametric signal for controlling the operation of the
shutter of said camera,
said automatic functions including an automatically controlled
electronic flash means, said automatic exposure control means
including means for sampling the ambient light at a point in time
early in the opening phase of the shutter of said camera,
means for producing a further parametric signal representative of
the result of the sampling of said ambient light, and
said binary logic control circuit includes means responsive to said
further parametric signal to control the actuation of said
electronic flash means, in accordance with the value of its ambient
light whereby said electronic flash means is actuated to produce a
flash whenever said ambient light is below a predetermined value
and to block the actuation of said electronic flash means whenever
the ambient light is above said predetermined value. .[.
2. In an automatic photographic camera featuring a plurality of
automatic functions, a control system for controlling the sequence
and actuation of said automatic functions, said control system
comprising:
means for producing a plurality of parametric signals
representative of parameters related to said automatic
functions,
a binary logic control circuit responsive to said parametric
signals for producing a plurality of control signals,
said binary logic control circuit including means for establishing
the selection and sequence of the actuation of said automatic
functions,
means responsive to said control signals to effect the actuation of
said automatic functions,
said control system including an automatic exposure control means
for controlling the operation of the shutter of said camera,
said control means including an integrating light sensing
means,
voltage reference means,
signal comparator means connected to said light sensing means and
to said voltage reference means for producing one of said
parametric signals as a function of the comparison of the outputs
of said voltage reference means and said light sensing means,
said binary logic control circuit including gating means responsive
to said one parametric signal for controlling the operation of the
shutter of said camera,
said control system further including focus control means for
automatically adjusting the focus of the lens system of said
camera,
said focus control means including an electric motor for driving
the adjusting means for said lens system, and
means correlated with the lens system for producing a focus related
parametric signal representative of the condition of focus of said
lens system,
said binary logic control circuit including means responsive to
said focus related parametric signal for controlling the
energization of said electric motor whereby to deenergize said
motor when a condition of best focus is indicated by said focus
related parametric signal..].
3. The control system as set forth in claim .[.2.]. .Iadd.7
.Iaddend.wherein said binary logic control circuit includes further
means responsive to said focus related parametric signal to block
the initiation of others of said automatic functions until the
completion of said automatic focus adjustments.
4. In an automatic camera featuring a plurality of automatic
functions, a control system for controlling the sequence and
actuation of said automatic functions, said control system
including means for producing a plurality of signals representative
of parameters relating to the operation of said camera,
control circuit means responsive to said signals for producing a
plurality of control signals,
said automatic functions including focussing control, exposure
control and electronic flash producing means, and
means connected to be responsive to said control signals for
effecting adjustment of the focus of said camera, for effecting
said automatic exposure control of said camera in accordance with
the illumination of a scene to be photographed, and for effecting
the control of the actuation of said electronic flash producing
means in accordance with the value of the ambient light whereby
said electronic flash producing means is enabled to produce a flash
whenever the ambient light is below a predetermined value and to
timely actuate said flash producing means.
5. The control system as set forth in claim 4 wherein one of said
control signals is effective to block the actuation of said
electronic flash producing means when the ambient light is above
said predetermined value.
6. The control system as set forth in claim 4 wherein said camera
includes means for resetting said automatic functions preparatory
to a new photographic cycle, and wherein said control circuit
includes means for completing the sequence of photographic
operations comprising means for effecting the actuation of said
means for resetting said automatic functions. .Iadd. 7. In an
automatic photographic camera featuring a plurality of automatic
functions, a control system for controlling the sequence and
actuation of said automatic functions, said control system
comprising:
means for producing a plurality of parametric signals
representative of parameters related to said automatic
functions,
a binary logic control circuit responsive to said parametric
signals for producing a plurality of control signals,
said binary logic control circuit including means for establishing
the selection and sequence of the actuation of said automatic
functions,
means responsive to said control signals to effect the actuation of
said automatic functions,
said control system including an automatic exposure control means
for controlling the operation of the shutter of said camera,
said control means including an integrating light sensing
means,
voltage reference means,
signal comparator means connected to said light sensing means and
to said voltage reference means for producing one of said
parametric signals as a function of the comparison of the outputs
of said voltage reference means and said light sensing means,
said binary logic control circuit including gating means responsive
to said one parametric signal for controlling the operation of the
shutter of said camera,
said control system further including focus control means for
automatically adjusting the focus of the lens system of said
camera,
said focus control means including motion producing means for
driving the adjusting means for said lens system, and
means correlated with the lens system for producing a focus related
parametric signal representative of the condition of focus of said
lens system,
said binary logic control circuit including means responsive to
said focus related parametric signal for controlling said motion
producing means whereby to inactivate said motion producing means
when a condition of best focus is indicated by said focus related
parametric signal. .Iaddend.
Description
CROSS REFERENCE TO RELATED APPLICATION
Subject matter disclosed but not claimed herein is described and
claimed in a copending application of Dean M. Peterson for
Photographic Apparatus filed on even date herewith. That Peterson
application was subsequently abandoned and refiled as application
Ser. No. 453,888 on Mar. 22, 1974 .Iadd.now U.S. Pat. No. 3,928,859
issued Dec. 23, 1975. .Iaddend.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to photographic apparatus. More
particularly, it relates to automatic control circuitry for an
automatic camera.
2. Description of the Prior Art
Heretofore many structures have been devised for providing what are
called automatic camera operations. Some of these have included
automatic exposure control systems which feature control either of
the time of exposure or the iris opening of the camera, or both.
Others have shown means for effecting an automatic focus in a
camera but not related to the automatic exposure control. Some
cameras have provided means for indicating that an insufficient
ambient light was available for a proper exposure of the film. Such
means however, were merely indicators and did not effect a control
function within the camera. Some camera included a built in
electronic flash unit. These however, required a selection by the
operator of the camera prior to the taking of the picture to effect
an operation of the flash unit.
SUMMARY OF THE INVENTION
In the above referenced copending application of Dean M. Peterson a
fully automatic camera is provided which teaches means for
effecting an automatic focus of the optical system of the camera,
means for effecting an automatic control for the exposure of the
film in the camera to a predetermined amount of light (the control
being effected by controlling both the aperture and the shutter
opening time). That camera also includes a built in electronic
flash unit which is automatically operative whenever insufficient
ambient light is available to effect a proper exposure of the film
in the camera.
It is an object of the present invention to provide an electronic
control circuit for an automatic camera of the type set forth in
the aforementioned copending application. It is another object of
the present invention to provide an improved electronic control
circuit for controlling timing and coordinating the operation of a
number of automatic features of an automatic camera.
It is yet another object of the present invention to provide an
automatic control circuit for an automatic camera which circuit
features binary logic control circuitry.
In accomplishing these and other objects, there has been provided,
in accordance with the present invention, a control circuit for an
automatic photographic camera which features a binary logic control
system connected to respond to each of several input parameters
developed by appropriate sensors built into the camera for
programming and controlling the sequence of a plurality of
automatic operations within the camera. For example, when a film
cartridge is loaded into the camera and a compartment door of the
film cartridge chamber is closed the film in the cartridge is
automatically advanced to the first film frame position by the
energization in one direction of a reversible electric motor.
Simultaneously, a built in electronic flash unit is charged in
readiness for use if needed in the subsequent taking of a picture.
When the operator of the camera aims the camera at a chosen object
and actuates the shutter release mechanism to initiate the picture
taking process, an automatic focus system is energized to
automatically adjust the lens system of the camera to bring the
object of the photograph into focus on a film plane. Through the
logic control system, other features of the camera operation are
blocked until such time as the focussing of the camera has been
accomplished. Upon completion of the focus adjustment, the shutter
of the camera is allowed to begin to open to admit light into the
film chamber of the camera. Means are provided for sensing the
amount of light so admitted through the shutter opening and to
provide a first and a second control signal. The first control
signal is in the nature of a sampling of the ambient light at a
time near the beginning of the opening of the shutter to determine
if there is sufficient light for the proper exposure of the film in
the camera. If insufficient light is available, the logic control
circuit responds to the sampling to provide, at a proper time in
the opening phase of the shutter, to trigger the operation of the
electronic flash unit. If, on the other hand, adequate light is
indicated by the sampling, a signal is applied through the logic
control circuit to block the actuation of the electronic flash
unit. The second control signal is an indication that enough light
has been admitted through the opening of the shutter to properly
expose the film in the camera. That control signal is also applied
through the logic circuit to effect a closure of the shutter.
Following the completion of the closure of the shutter the motor is
automatically actuated to advance the film in the camera to the
next film frame position and at the same time to reset the shutter
mechanism in readiness for a subsequent picture. Again
simultaneously, the electronic flash unit is recharged for a
subsequent use.
BRIEF DESCRIPTION OF THE DRAWING
A better understanding of the present invention may be had from the
following detailed description when read in connection with the
accompanying drawings, in which:
FIG. 1 is a schematic representation of a shutter mechanism for a
camera suitable for use in connection with the presen
invention;
FIG. 2 is a schematic representation of an adjustable lens system
for a camera embodying the present invention;
FIG. 3 is a schematic diagram of an electronic control system
embodying the present invention; and
FIG. 4 is a schematic diagram of a portion of an electronic control
system also embodying the present invention.
THE DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is illustrated a shutter mechanism basically of the
same type as that shown in the aforementioned copending Peterson
application. The shutter comprises a first shutter blade 2 and a
second shutter blade 4. The two shutter blades are constrained to
oppositely directed translational motion. Each of the shutter
blades has a configured opening 6, and 8, respectively, comprised
essentially of a circular opening and having a substantially
triangular radial extension protruding therefrom. In the shutter
closed position, as shown in FIG. 1, it may be seen that the two
openings completely out of alignment with each other, blocking the
admittance of light into the camera chamber. A complementary
driving member 10 in the form of an annulus or ring is coupled to
the two shutter blades 2 and 4, respectively. The shutter blade 2
includes a tab 12 extending from the edge thereof. A similar tab 14
extends from the lower edge of blade 4. The ring 10 has a radial
tab 16 which carries a driving pin 18. Pin 18 extends through a
slot in the tab 12 to couple the driving ring 10 to the first blade
2. Diametrically opposite from the radial tab 16 is a tang 20
extending from the periphery of the ring 10. The tang 10 carries a
pin 22 which, in turn, extends through a slot in the tab 14 of the
blade 4 to couple the blade 4 to the ring 10. At the other
extremity of the tang 20, there is coupled a driving link 24. The
driving link 24 is carried by a first driving plate 26 of a shutter
driving mechanism. Also included in the shutter driving mechanism
is a second driving plate 28. A first spring 30 is coupled between
the first driving plate 26 and a shoulder or boss 32 of the second
driving plate 28. A second spring 34 is connected between the boss
32 on the second driving plate 28 and a fixed reference point 36.
The spring 30 is arranged to bias the first driving plate 26 toward
the left, as shown in the illustrative embodiment. A latch member
38 engages the driving plate 26 to restrain it against the urging
of the spring 30. In the structure illustrated in FIG. 1 the latch
38 is kept in engagement with the plate 26 by the energization of a
magnet 40. Deenergization of the magnet 40 allows the latch 38 to
be disengaged from the plate 26 by the force of a spring 42.
Similarly, the second driving plate 28 is restrained against the
urging of the spring 34 by a latch 44. The latch 44 is held in
engagement with the plate 28 by the energization of a magnet 46.
Deenergization of the magnet 46 allows the latch 44 to be
disengaged from the plate 28 by operation of the force of a spring
48.
In the process of operating the camera, when the latch 38 is
released by the deenergization of the magnet 40, the drive plate 26
begins to move, under the urging of the spring 30, toward the left,
as shown in the illustrative embodiment. Since the ring 10 is
constrained to move in a rotational direction about a virtual axis,
concentric with the optical axis of the camera, the movement of the
drive plate 26 causes the ring 10 to be rotated in a clockwise
direction about its axis. The movement of the ring, in turn, causes
the two shutter blades to be moved in oppositely directed
translational motion such that the openings in the two shutter
blades move toward each other in an overlapping relationship to
produce a progressively larger aperture window through which light
is admitted to the chamber of the camera. When sufficient light has
been admitted for a proper exposure of the film in the camera, as
will be hereinafter shown, the magnet 46 is deenergized releasing
the second driving plate 28 to be moved to the right under the
urging of the spring 34. As the plate 28 moves to the right, it
carries the first plate 26 with it to return that plate to its
original position as shown in FIG. 1. The returning coupling
between the plate 28 and the plate 26 may be a simple abuttment
such as a shoulder or boss 32 which would then engage the end of
the plate 26 on the release of the latch 44. Returning the plate 26
to its original position restores the shutter blades to their
closed position as shown in FIG. 1. A reversible electric motor 50
is provided which, upon energization for movement in one direction
is operative to restore the second driving plate 28 to its original
position, the position shown in FIG. 1. At the same time the motor
50 is operative to restore the second driving plate 28 to its
original position, it is also operative through a coupling (not
here shown) to advance a film in the camera to the next film frame
position.
The mechanism thus far described and illustrated in FIG. 1 as well
as the mechanism illustrated in FIG. 2 and to be hereinafter
described is schematic in presentation for the purpose of
illustrating the environment for the electronic control circuit
constituting the present invention. The details of the mechanism is
shown, described, and claimed in the aforementioned copending
application of Dean Peterson.
In FIG. 2 there is shown a schematic representation of a lens
barrel 52 of a type suitable for use in conjunction with the
present invention. Within the lens barrel there is positioned a
multielement lens system. The first element 54 and the second
element 56 are fixed lens elements as is the fourth lens element
58. The third lens element is an adjustable lens element which may
be moved to effect the adjustment of the focus of the lens system.
To this end the third lens element 60 is mounted in a collar 62
which is externally threaded. A sleeve 64 is fixedly mounted within
the lens barrel 52 and is internally threaded to make with the
threads on the exterior of the collar 62. The upper surface of the
collar 52 is provided with a series of longitudinal grooves 56
which constitute a gear sector. A slide plate 68 is arranged to be
moved transversely of the axis of the lens barrel 52. At the
portion of the slide plate 68 adjacent the lens barrel 52 there is
formed a rack of gear teeth 70 which is arranged to engage the
grooves or gear teeth on the upper surface of the collar 52. Thus,
as the slide plate 68 is moved backward or forward transversely of
the lens barrels 52, the engagement of the rack 70 with the gear
teeth 66 on the collar 62 causes the collar and the third lens
element carried thereby to move axially of the lens system thereby
changing the focus adjustment of the lens system.
The slide plate 68 may be caused to move transversely of the lens
barrel manually by engaging the knurled member 72 by a finger of
the operator. On the other hand, the slide plate 68 may be caused
to move transversely of the lens barrel, thereby adjusting the
focus of the lens system automatically. To this end, the slide
plate 68 carries a second rack 74 which is engaged and driven by a
spur gear 76. The spur gear 76 is, in turn, driven by the motor 50
(the same motor used to accomplish a resetting of the shutter
mechanism and the advancement of the film to the next film frame
position). It is contemplated that the operation of the reversible
motor 50 in the one direction, as previously mentioned, effects the
resetting of the shutter mechanism and the film advancement
function, and when operated in the opposite direction is controlled
to effect the automatic focus adjustment of the lens system.
The slide plate 68 also carries a normally open switch 78. It will
be noted that the contacts of the switch 78 changed their position
as the position of the slide plate, itself, is changed. That is,
the position of the switch contact changes in accordance with the
focus adjustment of the camera. Means associated with the shutter
driving mechanism are provided for actuating or closing the
contacts of the switch 78 as the shutter blades are moved toward
their open position. This relationship is schematically represented
in FIG. 2 as a switch actuator or boss 80 mounted on and carried by
a first driving plate 26 (shown in fragmentary form). Again, the
structure shown in FIG. 2 is illustrative of the environment to
which the circuit of the present invention pertains.
In FIGS. 3 there is shown an automatic camera control circuit
embodying the present invention. Power for the circuit is obtained
from a battery 82 the positive terminal of which is connected to
the movable blade of a double-pole, single-throw switch 84. The
switch 84 is normally closed on a first contact connected to a
first positive bus 86. When the switch 84 is actuated, the positive
terminal of the battery 82 is connected to a second positive bus
88. The negative terminal of the battery 82 is connected through a
first and a second single-pole, single-throw switch 90 and 92,
respectively, serially connected, to a negative bus 94. The first
positive bus 86 is connected to a first terminal of a reversible
motor 50. The second terminal of the motor 50 is connected through
a switch 96 to the negative bus 94.
The first positive bus 86 is also connected to energize an
electronic flash circuit 98. Specifically, the bus 86 is connected
to one terminal of the primary of a transformer 100. The
transformer 100 is connected, with the capacitor 102, a transistor
104, a resistor 106, and the negative bus 94 in a free-running
oscillator configuration. The oscillatory pulses from the
aforementioned oscillator are applied by way of a capacitor 108 and
a diode 110 to establish a high voltage across a capacitor 112. It
will be noted that a flash tube 114 is connected directly across
the capacitor 112. Also connected directly across the capacitor 112
is a series circuit comprising a resistor 116, a zener diode 118,
and a resistor 120. An indicator lamp such as a neon bulb 122 is
connected across the resistor 120. When a predetermined charge has
been established on the capacitor 112, the indicator lamp will be
illuminated to indicate the readiness of the charging circuit for
the flash unit, although the high voltage charge on the capacitor
112 is applied across the electrodes of the flash tube 114, the
tube will not produce a flash of light until such time as a trigger
pulse has been applied to the trigger electrode 124 thereof. A
trigger circuit for the flash unit includes an SCR (silicon
controlled reactifier) 126 has its anode connected through a
resistor 128 to the junction between the resistor 116 and the zener
diode 118. The cathode of the SCR 126 is connected directly to the
negative bus 94. The gate electrode of the SCR 126 is connected
through a bias resistor 130 to the negative bus 94. The gate
electrode is also connected to a control circuit to be described
hereinafter. The anode of the SCR 126 is also connected through a
capacitor 132 to a primary winding of an autotransformer 134. The
secondary winding of the autotransformer 134 is connected directly
to the trigger electrode 124 of the flash tube 114.
The second positive bus 88 is connected to one energizing terminal
of an autofocus circuit 136, the other energizing terminal of which
is connected to the negative bus 94. The specific details of the
autofocus circuit are not a part of the present invention and are
not shown herein. Any of a number of automatic focus determining
circuits are suitable for use herein; the only requirement being
that at the point of determination of best focus, a minimum or null
signal be applied to the output lead 138.
The second positive bus 88 is also connected to energize an
automatic exposure control circuit 140. The other energizing leads
of the automatic exposure control circuit 140 are also connected to
the negative bus 94. The automatic exposure control circuit
includes a photosensitive detector 142 such, for example, as a
silicon diode detector. The photosensitive detector 142 has one
electrode connected to the positive supply bus 88. The other
electrode thereof is connected through the emitter-collector path
of a transistor 144 to the negative supply bus 94. The junction
between the photosensitive detector 142 and the collector of the
transistor 144 is connected to the gate electrode of a field effect
transistor (FET) 146. The source electrode of the FET 146 is
connected to the positive bus 88; while the drain electrode is
connected through a resistor 148 to the negative bus 94. The FET
146 thus comprises an amplifier for the output signal of the
photosensitive detector 142. The output terminal, the drain
electrode, of the FET 146 is connected through a resistor 150 to
one input terminal of a first comparator 152. The same output
terminal of the FET 146 is also connected through a second resistor
154 to one input terminal of a second comparator 156. A voltage
reference circuit 158 is connected between the positive supply bus
88 and the negative supply bus 94. A first reference voltage from
the voltage reference circuit 158 is applied to a second input
terminal of the first comparator 152 while a second reference
voltage from the voltage reference circuit 158 is applied to a
second input terminal of the second comparator 156. The first
comparator 152 is so arranged that when the signal applied to the
two input terminals is equal, a relatively low or logical "zero"
signal appears at the output thereof. On the other hand, the second
comparator 156 is so arranged that when the two signals applied to
the input thereof are equal, a relatively high or logical 1 appears
at the output terminal thereof. It should be noted, at this point,
that the reference signal applied to the second terminal of the
second comparator 156 is a much lower voltage signal then is the
reference signal applied to the second terminal of the first
comparator 152. The purpose of these different level voltage
reference signal will appear hereinafter.
The positive bus 88 is also connected to energizing relationship to
the motor control circuit 160. It will be remembered that for
energization of the motor for rotation in one direction, the motor
control circuit was connected to the first positive bus 86 with the
energization of the motor going from the positive bus 86 through
the motor and a closed switch 96 to the negative bus 94. For
energization of the motor for operation in the opposite direction,
the energizing current flow is from the bus 88 through the
emitter-collector path of a transistor 162, through the motor then
through the collector-emitter path of a transistor 164. The base
electrode of the transistor 162 is connected through a resistor 166
to the collector electrode of a transistor 168 the emitter of the
transistor 168 is connected to the negative bus 94. The base of the
transistor 154 is connected through a resistor 170 to the positive
bus 88. So long as the switch 84 is in contact with the first
positive bus 86, the transistor 164 is biased to an "off"
condition. Similarly, the transistor 162 is normally bias to an
"off" condition until turned on by a signal to be defined
hereinafter.
The positive bus 88 is also connected in an energizing relationship
with the first and second magnets 40 and 46, respectively,
previously referenced in the discussion of FIG. 1. One terminal of
the coil of the magnet 40 is connected to the positive supply bus
88. The other terminal of the coil 40 is connected, through the
collector-emitter path of a transistor 172, to the negative supply
bus 94. Similarly, one terminal of the coil of the magnet 46 is
connected to the positive supply bus 88 while the other terminal is
connected, through the collector-emitter path of a transistor 174,
to the negative supply bus 94.
The interrelationship of the foregoing circuit components is under
the control of a logic circuit 176. The logic circuit 176 is
brought into operation whenever the switch 84 is closed on the
second positive supply bus 88. A resistor 178 and a capacitor 180
are serially connected between the positive supply bus 88 and the
negative supply bus 94. That arrangement supplies a positive bias
signal at the junction between the resistor 178 and the capacitor
180 to initially "set" a plurality of flip-flop units, as will be
described hereinafter. The first of the flip-flop unit comprised of
a pair of cross-coupled NAND gates 182 and 184, respectively. A
second flip-flop unit is comprised of a second pair of
cross-coupled NAND gates 186 and 188, respectively. A third
flip-flop unit includes a third path of cross-coupled NAND gates
190 and 192, respectively. A fourth flip-flop unit includes a
fourth pair of cross-coupled NAND gates 194 and 196, respectively.
The junction between the resistor 178 and the capacitor 180 is
connected to one of the input terminals of each of the NAND gates
182, 186, 190 and 194. This connection assures that when the switch
84 is closed on the second positive bus 88 each of the NAND gates
182, 186, 190 and 194 will be controlled to produce a "high" or
logical 1 at the output thereof. The output terminal of the first
NAND gate 182 is connected to the base electrode of a transistor
144 through a resistor 198. The output terminal of the gate 182 is
also connected through a resistor 200 to the base electrode of the
transistor 168. That same output terminal is further connected
through a resistor 202 to the base electrode of a transistor
172.
In the cross-coupling relationship, the output terminal of the gate
182 is connected to one of the input terminals of the gate 184. In
turn, the output terminal of the gate 184 is connected to the other
input terminal of the gate 182. The output lead 138 from the
autofocus control circuit is connected to the second input terminal
of the gate 184. In the cross-coupling relationship, in the second
flip-flop unit, the output terminal of the gate 188 is connected to
the second input terminal of the gate 186 while the output terminal
of the gate 186 is connected to one of the input terminal of the
gate 188 is connected through a selectively operated switch 204 to
the negative supply bus 94. The output terminal of the gate 186 is
connected to one input terminal of a NAND gate 206. The other input
terminal of the NAND gate 206 is connected to the output terminal
of the second comparator 156.
The output terminal of the gate 206 is connected to one input
terminal of the gate 192 forming a part of the third flip-flop
unit. The output terminal of the gate 192 is connected to the
second input terminal of the gate 190 while the output terminal of
the gate 190 is connected to the other input terminal of the gate
192 to complete the cross-coupled relationship. The output terminal
of the gate 190 is also connected to one input terminal of a NAND
gate 208. The second input terminal of the NAND gate 208 is
connected through a resistor 210 to the negative supply bus. The
second input terminal of the gate 208 is also connected through a
selectively operated switch 78 to the positive supply bus 88. The
output terminal of the gate 208 is connected through an inverter
212 to the gate electrode of the SCR 126 in the trigger circuits of
the flash unit 98.
The output terminal of the gate 208 is also connected to one of the
input terminals of the gate 196 forming part of the fourth
flip-flop unit. It will be noted that the gate 136 is a 3 input
NAND gate the output terminal of which is connected to the second
input terminal of the gate 194. In its cross-coupled relationship
the output terminal of the gate 194 is connected to a second input
terminal of the gate 196. The third input terminal of the gate 196
is connected to the output terminal of the first comparator 152.
The output terminal of the gate 194 is also connected through a
resistor 214 to the base electrode of the transistor 174.
MODE OF OPERATION OF THE PREFERRED EMBODIMENT
The switch 92 may be in the form of a conventional on-off switch.
On the other hand it may serve the same function by being
interlocked with a functional member of the camera such, for
example, as a retractable view finder. In the latter case, the
switch would be closed whenever the view finder is withdrawn from
its retracted position to make the camera ready for use. In either
case to render the camera ready for use, the switch 90 would be
closed. The switch 92, it is contemplated, will be a safety
interlock switch correlated with the operation of a door member
which must be opened to insert a film cartridge. The switch 92 will
be closed whenever the door to the film cartridge chamber is
closed. Both switches must be closed in order to render the circuit
operational.
Assume that the switch 90 has been closed either manually or by the
actuation of the functional element such as a view finder. The door
to the film cartridge chamber is opened for the insertion of a film
cartridge. At that time the switch 92 will be opened. When the film
cartridge has been inserted and the door closed, the circuit
becomes functional. As in substantially all of the cameras designed
for use with the so-called easy-load film cartridges, the camera
includes a feeler which is positioned to sense the presence or
absence of a perforation placed in the edge of the film by the film
manufacturer to indicate appropriate film frame positions. The
switch 96 is so interlocked with such a feeler that the switch 96
is closed whenever a perforation is not present under the feeler.
Accordingly, when the switch 92 is closed after having inserted a
cartridge, the switch 96 will also be closed as a result of the
absence of a perforation in the film. With the switch 96 closed,
current will flow from the first positive supply bus 86 through the
motor 50, and to the negative supply bus 94. The current flow
through the motor under these conditions will cause the motor to
rotate in one predetermined direction. This rotation will be
coupled into the camera apparatus to cause the film to be advanced
until such time as a perforation is engaged by the feeler, causing
the switch 96 to be opened.
At the same time, if the shutter mechanism had not previously been
reset to its ready or cocked position, the operation of the motor
in this predetermined direction will also cause the shutter
mechanism to be so reset.
Simultaneously, the electronic flash unit will be energized, the
oscillator 100 will start oscillating thereby charging the
capacitor 112 to a predetermined level. When the predetermined
level has been reached, the indicator lamp 122 will be lit to
indicate that the flash unit is ready for operation. At that point
the switch 84, which is coupled to the shutter release button of a
camera may be actuated to initiate the taking of a picture.
The actuation of the switch 84 causes the power supply battery 82
to be connected to the second positive bus 88. When the voltage is
applied to the positive bus 88, the signal developed at the
junction between the resistor 78 and the capacitor 180 in the logic
circuit 176 causes the gates 182, 186, 190 and 194 all to be
actuated to their "set" condition. That is, a relative high or
logical 1 appears at the output terminal of each of those gates. As
was previously mentioned, the output of the gate 182 is connected
simultaneously to the base electrode of the transistor 144,
transistor 168 and transistor 172. The application of the high or
logical 1 to the base of the transistor 144 causes that transistor
to turn "on" to a conductive condition. While the transistor 144 is
conductive, the automatic exposure control circuit is
inoperative.
Similarly, the application of the logical 1 to the base of the
transistor 168 causes that transistor to be conductive. When the
transistor 168 becomes conductive, the transistor 162 becomes
conductive. In the meantime the transistor 164 has been rendered
conductive simultaneously with the closure of the switch 84 to the
positive bus 88. With the transistors 162 and 164 now conductive,
current from the bus 88 flows through the motor 50 in the opposite
direction from that previously discussed. This causes the motor to
be operated in the opposite direction. As was previously mentioned
it is contemplated that when the motor is operated in the opposite
direction it will be coupled through the gear 76 to the rack 74 to
effect an adjustment of the focus of the lens system of the camera,
as was discussed in connection with the description of the
structure illustrated in FIG. 2. Correlated with the adjustment of
the lens system of the camera is the autofocus control circuit 136.
When a condition of best focus is obtained through operation of the
autofocus system and the automatic adjustment of the lens system, a
relatively low or logical 0 is applied to the output lead 138 from
the autofocus control circuit. That logical 0 is applied to one of
the input terminal of the gate 184 forming a part of the first
flip-flop unit. The application of that logical 0 to the input of
the gate 184 causes the flip-flop to change states, producing a
relative low or logical 0 at the output of the gate 182. That
logical 0 when applied to the base electrode of the transistor 168
causes the transistor 162 to become non-conductive, thereby
stopping the operation of the motor 50.
Simultaneously, the logical 0 from the output terminal of the gate
182 is applied to the base electrode of the transistor 172,
rendering that transistor non-conductive, de-energizing the magnet
40 thereby allowing the shutter mechanism to begin to open.
At the same time, the logical 0 from the output of the gate 182 is
also applied to the base electrode of the transistor 144 rendering
that transistor non-conductive. When the transistor 144 is rendered
non-conductive, the exposure control circuit 140 becomes
operative.
It was previously mentioned that it is contemplated that the
photosensitive detector 142 will be located in the camera chamber
between the shutter and the film frame. Therefore, as the shutter
mechanism begins to open, light is admitted to the chamber and
falls on the photosensitive detector 142. In the preferred
embodiment of the present invention, the photosensitive detector is
of a type which provides self-integration. A silicon photocell is a
detector of the type which will provide such self-integration for a
time period sufficient for the purposes of this invention. The
output signal from the photosensitive detector 142 is amplified by
the FET 146 and compared separately with the two reference signals
from the voltage reference source 158. Again as was previously
mentioned, the reference signal applied to the second comparator
156 is a relatively low valued signal. The output terminal of the
comparator 156 is connected to one of the input terminals of the
gate 206. The other input terminal of the gate 206 is connected to
the output terminal of the gate 186 in the second flip-flop unit.
Initially, the second flip-flop unit is in its "set" condition with
a logical 1 appearing at the output of the gate 186. That logical 1
is applied as one of the input signals to the gate 206. Until such
time as the signal from the photosensitive detector reaches a point
of equivalence with the reference voltage applied to the input of
the second comparator 156, the output of the voltage comparator 156
is a relatively low or logical 0. That logical 0 is applied as the
other output signal to the gate 206. Consequently, the output of
the gate 206 is a relatively high or logical 1, which is applied as
one of the input signals to the gate 192 of the third flip-flop
unit. The third flip-flop unit has also been established in its
"set" condition with a logical 1 appearing at the output of the
gate 190. That logical 1 applied to one of the input terminals of
the gate 208 together with the logical 0 applied to the other input
terminal thereof produces a logical 1 at the output of the gate
208. The logical 1 at the output of the gate 208 is inverted by the
inverter 212 to produce a logical 0 at the trigger electrode of the
SCR 126 in the electronic flash unit 98.
At this point it might be noted that when the switch 84 was
switched from contact with the bus 86 to effect a contact with the
bus 88, the oscillator of the electronic flash unit would be
deenergized. The deenergization of the oscillator in the electronic
flash unit 98 reduces any possibility of the oscillator signal
producing a spurious or noise signal in any of the other circuit
components during subsequent operation. Notwithstanding the
deenergization of the oscillator, the high voltage charge remains
stored on the capacitor 112.
The switch 204 connected to one of the input terminals of the gate
188 of the second flip-flop unit is normally opened. However, that
switch is correlated with the movement of the shutter blades such
that very shortly after the shutter begins to open, for example,
when the opening has reached a condition equivalent to a stop of
f/11, the switch will be closed. When the switch 204 is closed, a
relative low or logical 0 is applied to the input terminal of the
gate 188, causing the second flip-flop unit to change its state to
produce a relative low or logical 0 at the output of the gate 186.
If, before the switch 204 is actuated, the signal from the
photosensitive detector has reached a level which is equal to or
greater than the reference signal applied to the comparator 156,
the output signal from the comparator 156 will be switched to a
relative high or logical 1. That logical 1 applied to the input of
the gate 206 causes that gate to produce an output signal which is
a logical 0. The logical 0 from the gate 206 applied as an input to
the third flip-flop unit causes the flip-flop unit to change its
state to produce a logical 0 at the output of the gate 190. That
logical 0 applied to the input of the gate 208 maintains the output
of that gate at a logical 1 which, in turn, holds the logical 0 at
the trigger electrode of the SCR 126 in the electronic flash
circuit 98. When, subsequently, the switch 204 is closed causing
the second flip-flop unit to change its state to produce a logical
0 at the output of the state 186, the gate 206 will change its gate
to produce a logical 1 at its output. That logical 1 applied to the
input of the gate 192 will not, however, cause the second flip-flop
unit to change its state. Therefore, a logical 0 will be applied
from the output of the gate 190 to one input to the gate 208.
It will be remembered that the switch 78 is also correlated with
the movement of the shutter mechanism and is positionally adjusted
in accordance with the adjustment of the focus system. When during
a later stage in the opening of the shutter, the switch 78 is
closed, a high or logical 1 signal is applied to the other input
terminal of the gate 208. Since the output of the gate 190 had been
switched to a logical 0, the gate 208 is disabled and does not
respond to the closure of the switch 78 to cause a change in its
output state. Therefore the output of the inverter 212 remains at a
low or logical 0 and the electronic flash unit is not fired.
Therefore it can be seen that the value of the reference signal
applied to the input of the comparator 156 is such a value that
when the scene brightness, as determined by the light sampling at a
shutter opening of f/11, is sufficient to produce a proper exposure
of the film in the camera within the time frame suitable for
hand-held cameras (1/30 of a second) the electronic flash unit will
not be fired.
On the other hand, if the switch 204 were to be closed before the
comparator 156 changed its output from a logical 1 to a logical 0,
a different situation would exist. The closure of the switch 204
causes the second flip-flop unit to change its state to produce a
logical 0 at the output of the gate 186. That logical 0 applied to
the input of the gate 206 does not change the state of the output
of the gate 206, nor will the subsequent switch of the output of
the comparator 156 from a logical 0 to a logical 1 change the
output state of the gate 206. Therefore the condition of the third
flip-flop is not changed and a logical 1 is still applied from the
output terminal of the gate 190 to one of the input terminals of
the gate 208. This relationship indicates that the scene
brightness, as sampled at f/11, is not sufficient to produce an
adequate exposure of a film in the camera within the alloted time
frame. Therefore, a subsequent closure of the switch 78 applies a
logical 1 to the other input of the gate 208, causing the state of
that gate to switch to produce a logical 0 output. That signal,
inverted by the inverter 212, produces a logical 1 or a high signal
applied to the trigger electrode of the SCR 126 in the electronic
flash unit 98. The application of that logical 1 or high signal to
the trigger electrode of the SCR 126 causes the SCR 126 to become
suddenly conductive, dumping the charge on the capacitor 132 and
producing a triggering signal across the transformer 134 to the
trigger electrode 124 of the flash tube 114, thereby initiating a
flash discharge through the tube 114.
The fourth flip-flop unit had also been established in its "set"
condition with a logical 1 at the output terminal of the gate 194.
That logical 1 when applied to the base electrode of the transistor
174 maintains the magnet 46 in an energized condition. It will be
noted that in the fourth flip-flop unit the gate 196 is a three
input gate. In the initial condition a logical 1 is applied to each
of the three input terminals of the gate 196. When the gate 208 was
caused to change its state to produce a logical 0 at its output,
that logical 0 causes the fourth flip-flop unit to change its state
to produce a logical 0 at the output of the gate 194. The logical 0
at the output of the gate 194, when applied to the base electrode
of a transistor 174, renders the transistor 174 non-conductive,
de-energizing the magnet 46, thereby releasing the second driving
plate 28 of the shutter mechanism and allowing the shutter
mechanism to close.
If, on the other hand, the scene brightness, as sampled by the
photosensitive detector at f/11, was sufficient to allow a proper
exposure of the film in the camera within the alotted time frame,
as hereinbefore noted, the gate 208 will not have changed its state
when the switch 78 is closed. Under those conditions, the magnet 46
remains energized, holding the shutter mechanism in the open or
opening condition. In the meantime, the photosensitive detector 146
continues to integrate the light admitted through the shutter
opening until such time as the magnitude of the signal from the FET
amplifier 146 is equal to the magnitude of the reference voltage
applied to the comparator 152. When the equality has been reached,
the output signal from the comparator 152 switches from a logical 1
to a logical 0. That logical 0 is applied directly to one of the
input terminals of the gate 196 of the fourth flip-flop unit. That
logical 0 also causes the fourth flip-flop unit to change its state
to produce a logical 0 at the output of the gate 194, rendering the
transistor 174 non-conductive, de-energizing the magnet 46, and
allowing the shutter mechanism to close. Thus it may be seen that
the magnitude of the reference voltage applied to the comparator
152 is such as to indicate that sufficient light has been admitted
through the shutter opening to effect a proper exposure of the film
within the camera.
After completion of the exposure, the returning movement of the
second driving plate 28 causes the switch 96 to be again closed.
Also coincident with the completion of the exposure of the film in
the camera to produce a photograph, the operator of the camera
would release his finger from the shutter release button, thereby
allowing the switch 84 to return to its initial position in
engagement with the first positive bus 86. With the switch 84
closed on the positive bus 86, the returning movement of the
driving plate 28 causing a closure of the switch 96, again
establishes an energization of the motor 50 in the first mentioned
direction. The shutter mechanism is thereby reset to its ready or
cocked condition and the film in the cartridge is advanced to the
next film frame position. Simultaneously, the oscillator in the
electronic flash unit is again energized and the capacitor 112
recharged in readiness for a subsequent flash.
DETAILED DESCRIPTION OF THE SECOND EMBODIMENT
In FIG. 4 there is shown a somewhat modified circuit. If, in the
circuit of FIG. 3 there were no provision for the automatic focus
control circuit, there would be no way of turning "off" the
transistor 144 to allow the automatic exposure control circuit 140
to begin operating. Accordingly, the embodiment shown in FIG. 4
does not include an autofocus circuit. Instead, the second positive
bus 88 is connected through a resistor 216 to the input terminal of
an inverter 218. The output of the inverter 218 is applied to the
control input terminal of the gate 184.
Without the automatic focus feature, the camera lens would be
manually adjusted, as by manual adjustment of the slide plate 68
(FIG. 2) before the shutter release mechanism is actuated. Thus,
there would be no need to effect a time delay before the shutter
mechanism and the automatic exposure means is put into operation.
Accordingly, when the shutter release button is actuated by the
camera operator, the switch 84 is again moved from engagement with
the first positive bus 86 to engagement with the second positive
bus 88. As soon as the positive potential from the battery 82 is
applied the output of the gate 182 of the first flip-flop unit is
driven to a "low" or logical 0. The application of that logical 0
to the base of the transistor 144, causes that transistor to become
non-conductive, thereby allowing the automatic exposure control
circuit 140 to be operative.
At the same time, the logical 0 from the gate 182 is applied to the
base electrode of the transistor 172, de-energizing the first
magnet 40. The de-energization of the magnet 40 allows the shutter
mechanism to begin to open. From there on out, the operation of the
control circuit is the same as that set forth in the discussion of
the circuit of FIG. 3.
It will, of course, be appreciated that, if the automatic focus
feature is not include in the camera, there will be no need for the
control circuit controlling the operation of the motor 50 in the
"autofocus" direction, shown in FIG. 3 as counter clockwise.
Therefore, without the automatic feature, transistors 162, 164 and
168, their associated circuitry and their functions would be
deleted from the circuit shown in FIG. 3.
Thus, it may be seen that there has been provided, in accordance
with the present invention, an automatic control circuit for an
automatic camera, the circuit providing control of the timing and
sequential coordination of the several automatic features of the
camera.
* * * * *