Abstract: A power source device to and from which an interchangeable first device can be attached and detached and operating in such a manner that when the first device is attached and when the first device is judged to be normally operating, electric power is supplied at all times to the first device, while when the first device is not attached, or when, though the first device is attached, the first device is judged not to be normally operating, electric power is supplied in a predetermined periodicity to the first device.

Abstract: Disclosed is an interchangeable lens system which comprises an interchangeable lens and a camera. the interchangeable lens includes a driving circuit controlled by data transmitted from the camera to the lens such that it displaces a controlled member of the lens, a detection circuit for detecting a displacement of the driving circuit, and a correction circuit for converting the output characteristics of the detection circuit into predetermined common characteristics. The camera includes a control circuit for driving the driving circuit in the interchangeable lens in response to the output of the detection circuit in the interchangeable lens.

Abstract: In a rotation phase control device which forms phase control information by carrying out at least an integrating process on phase error information obtained according to a phase difference between a rotation phase detection signal indicating the rotation phase of a rotary body and a reference signal, the phase control information is temporarily invalidated when the phase difference becomes a value within a given range.

Abstract: An interchangeable lens system comprising a lens unit; a camera body provided with a first electric power supplying battery; a conversion adapter for connecting the camera body with the lens unit, thereby enabling electric power supply from the battery in the camera body to the lens unit; a second electric power supplying battery connected to the conversion adapter and controllable independently from the first battery; and a control circuit for enabling electric power supply from the second battery to the lens unit only when the camera body is connected to the conversion adapter.

Abstract: A camera system, which controls the function of a lens assembly on the basis of control information serially transmitted from a camera assembly, is provided with a communication circuit which effects communication of the control information and which is capable of changing the number of communication words associated with the communication, and a circuit for transmitting, if the number of communication words is changed, the changed number of communication words from the camera assembly to the lens assembly.

Abstract: An interchanageable-lens type camera system having a camera body and a lens unit includes an actuator disposed on the side of the lens unit, a control signal source disposed on the side of at least one of the camera body and the lens unit to control the actuator, an identification data forming circuit for forming identification data indicative of the presence, kind or absence of the control signal source in the camera body or the lens unit, and a communication part for transmitting the identification data between the camera body and the lens unit, wherein a control signal produced by the control signal source is supplied to the actuator on the basis of the identification data.

Abstract: A camera system comprising a lens unit and a camera unit detachably attached to each other, the camera system having a control circuit for controlling the operation of the lens unit and the operation of the camera unit so as to synchronize a phase of the operation of the lens unit with a phase of operation of the camera unit, and a communication circuit for effecting communication between the camera unit and the lens unit by using a reference signal for obtaining the synchronization between the phase of operation of the lens unit and the phase of operation of the camera unit.

Abstract: A condensed polycyclic, polynuclear aromatic thermosetting resin with improved moldability which is prevented from forming a cloud on a mold during molding is disclosed. The resin is a prepolymer derived by condensation polymerization of a condensed polycyclic aromatic compound or a mixture thereof with a monocyclic aromatic compounds and an aromatic compound having at least two hydroxymethyl groups as a crosslinking agent in the presence of an acid catalyst. The resin has a flow temperature of not higher than 150.degree. C. The acid catalyst is water-insoluble or when it is water-soluble the resin has an insolubilized acid ratio of at least 50%. The resin is useful in the manufacture of thermoset molded articles having good heat resistance and good mechanical and electrical properties. It can be blended with a filler and/or reinforcing agent to form a molding compound.

Abstract: Disclosed is an interchangeable lens system which comprises an interchangeable lens and a camera. The interchangeable lens includes a driving circuit controlled by data transmitted from the camera to the lens such that it displaces a controlled member of the lens, a detection circuit for detecting a displacement of the driving circuit, and a correction circuit for converting the output characteristics of the detection circuit into predetermined common characteristics. The camera includes a control circuit for driving the driving circuit in the interchangeable lens in response to the output of the detection circuit in the interchangeable lens.

Abstract: In an information signal reproducing apparatus of the kind reproducing an information signal from a tape-shaped recording medium on which pilot signals of four different kinds having different frequencies are cyclically recorded in rotation along with the information signal, reference signals of four different kinds which correspond to the pilot signals of four different kinds and are generated one after another in a switch-over cycle to be used for tracking control together with these pilot signals. The reference signals are arranged to be generated one after another in a switch-over cycle which differs from the normal switch-over cycle during a specific period following change-over of the tape-shaped medium moving speed from one speed to another.

Abstract: An apparatus for reproducing an information signal from a tape-shaped record bearing medium on which many helical tracks are formed, which is so constructed that while the tape-shaped record bearing medium is intermittently moved in longitudinal direction, the moving distance during traveling of the medium is determined by using a reproduced signal from the head when the medium is stopped, whereby the precise tracking is maintained constantly during travelling.

Abstract: A system for recording and reproducing includes a first instruction and display device, a second instruction and display device separably electrically connected with the first such device and sensing apparatus for detecting whether the second device is connected to or disconnected from the first device. A recording/reproducing controller is operably responsive to instructions generated by the devices to operate a recorder/reproducer unit and is dependent on the sensing apparatus for controlling the displays of the first and second devices. In a VTR application, the first device is included in the body of the VTR and the second device is a remote controller. The sensing apparatus detects when the remote controller is operatively connected to the VTR and the controller provides for activation of the display of the remote controller under such condition.