摘要:
When a trigger lever is depressed, both a focus adjuster ring and a control disk commence to rotate in unison, driven by a spring mechanism. Position-sensing switches receive signals indicating which subject-distance setting the focus adjuster ring should be arrested at, and furthermore are opened and closed by the control disk during movement of the latter. When the focus adjuster ring reaches the required subject distance setting, it is arrested and kept arrested, thereby completing an automatic focussing operation, but the control disk continues to turn on to its end position, at which it causes the shutter mechanism of the camera to open and furthermore the exposure-timing circuit of the camera to initiation a scene-light-dependent exposure-timing operation.
摘要:
When a trigger lever is depressed, both a focus adjuster ring and a control disk commence to rotate in unison, driven by a spring mechanism. Position-sensing switches receive signals indicating which subject-distance setting the focus adjuster ring should be arrested at, and furthermore are opened and closed by the control disk during movement of the latter. When the focus adjuster ring reaches the required subject distance setting, it is arrested and kept arrested, thereby completing an automatic focussing operation, but the control disk continues to turn on to its end position, at which it causes the shutter mechanism of the camera to open and furthermore the exposure-timing circuit of the camera to initiation a scene-light-dependent exposure-timing operation.
摘要:
A distance measuring system generates an in-range signal when an object is located within a range of focus or a zone of protection, as the case may be. The system utilizes a single infrared transmitter and two receivers in order to determine the position of the object by triangulation.
摘要:
A first photodetector arrangement comprises three adjoining photodetectors, and a second comprises six. First and second optics, and the two photodetector arrangements, are located immovable on the camera, and the optics project onto the first arrangement an image of a subject which is to form the basis of a subject-distance measurement, without shift between image and photodetectors of the first arrangement so long as the subject-distance is within one of the ranges the system is to furnish; whereas the image projected onto the second photodetector arrangement shifts relative thereto in dependence upon the distance to the subject. The six photodetectors of the second arrangement are subdivided, for signal-processing purposes, into four successive groups, respectively comprised of the first, second and third photodetector, the second, third and fourth, the third, fourth and fifth, etc. A plurality of comparisons are performed by signal-evaluating circuitry, on the basis of absolute-value versions of the differences between the output signals of individual photodetectors in the first arrangement and in successive photodetector-groups within the second arrangement, to automatically ascertain, sequentially or non-sequentially, which photodetector-group in the second photodetector arrangement is in receipt of an image best corresponding to that cast onto the first photodetector arrangement, thereby determining the subject-distance setting best corresponding to the true subject-distance value.
摘要:
Pulses of radiation are emitted from the camera to the subject, reflected back to the camera, and incident upon two detectors. The successive pulses produced by the two detectors are applied to respective integrators which trip respective threshold circuits when and if their integral signals reach the threshold value. This inherently reduces detector and other noise present in the processing circuitry. A tolerance-range counter ascertains whether or not, after one threshold circuit is tripped, the other becomes tripped within a predetermined time interval.
摘要:
First and second photodetector signals, whose relative amplitudes depend upon focus error, are integrated to form respective first and second integral signals whose relative rates of change are dependent upon focus error. Each integral signal is applied to two comparators, one whose threshold level is reached first and the other having a threshold level which would be reached second. When one or the other of the two integral signals reaches its first-reached threshold level, this applies a corresponding signal to the data input of a respective flip-flop, and when this faster-changing integral signal then reaches its second-reached threshold level this clocks both such flip-flops. The time elapsing between the faster-changing integral signal reaching its first-reached and then its second-reached threshold level constitutes a tolerance interval, during which the slower-changing integral signal is given an opportunity to try to reach its respective first-reached threshold level. If the slower-changing integral signal reaches its first-reached threshold level within the tolerance interval, then a corresponding signal is applied to the data input of its associated flip-flop as well before the two flip-flops are clocked, with the result that the states of the two flip-flops are the same as if both integral signals had indentical rates of change of value.
摘要:
A digital control circuit for use in automatic-focus cameras is disclosed, which is suitable for use in self-focusing systems which determine focus by means of triangulation. The system corrects for motor oscillation about a state of proper focus, defocusing caused by inertia, and for an inability to evaluate proper state of focus caused by large distances between the camera and a subject.
摘要:
A digital control circuit for use in automatic-focus cameras is disclosed, which is suitable for use in self-focusing systems which determine focus by means of triangulation. The system corrects for motor oscillation about a state of proper focus, defocusing caused by inertia, and for an inability to evaluate proper state of focus caused by large distances between the camera and a subject.
摘要:
At the start of each focussing operation, the camera objective is at a first extreme subject-distance setting and is moved in a first direction therefrom towards the second extreme subject-distance setting. A focus-evaluating circuit comprises first and second photodetectors located to receive light from the subject and a comparing circuit which compares the light incident on the photodetectors and in dependence upon the present subject-distance setting generates first and second signals respectively indicating that the subject-distance setting should be changed in the first direction or in the opposite second direction, such circuit having bidirectional character and furthermore establishing a tolerance range of acceptable distance-setting error within which both the first and second signals are generated. During the unidirectional change of subject-distance setting, the appearance of the first signal leads to generation of a stop signal commanding that the progressive change of distance setting be stopped. Accordingly, the unidirectional change of setting is commanded to stop at the point where the changing distance setting just enters into the tolerance range of the bidirectional evaluating circuitry.