Abstract: A camera module for use in a surveillance camera system is provided. The camera module includes a housing and a pan-and-tilt mechanism that is mounted to the housing. The pan-and-tilt mechanism includes a pan motor for panning a camera and a tilt motor for tilting the camera. The pan motor is mounted on the pan-and-tile mechanism so as to be stationary relative to the housing. A slip ring, mounted to the pan-and-tilt mechanism, provides electrical connections to the tilt motor and the camera and a flex cable connects the camera to the slip ring. Also provided are methods for controlling unique functions of the surveillance camera system. Calibration of a home pan position for the camera is achieved by monitoring an optical homing sensor. Calibration of a home tilt position for the camera is accomplished by driving the camera against a stop. Thereafter, pan and tilt positions of the camera are tracked relative to the home pan and tilt positions.

Abstract: A video surveillance system includes a plurality of remote surveillance units, each of which has a video camera mounted in a dome housing. The video camera is panned and/or tilted to a desired orientation within the dome by a pan motor and/or a tilt motor. The surveillance system also includes a keyboard for entering user commands, a joystick for controlling the positioning of the cameras, a central processing unit for interpreting the user commands and the joystick movements, and a communication system for issuing operating commands to the remote surveillance units. Each remote surveillance unit is constructed and arranged to store and to recall selected camera control parameters in association with selected pan and tilt coordinates in response to commands entered by the user. The camera control parameters include white balance, focus, and shutter speed settings for the camera. Additionally, automatic control of the camera exposure, white balance, and focus is provided.

Abstract: A stylus cleaner arm is pushed back to a retracted position when a record-bearing caddy is inserted into the player to load an enclosed record therein. The cleaner arm is held in the retracted position by a record retaining spine upon subsequent jacket withdrawal. The cleaner arm follows the caddy as it is withdrawn from the player after record playback. The cleaner arm engages a switch which actuates a stylus lowering device to lower a pickup stylus onto a cleaning pad disposed on the cleaner arm. The cleaning pad wipes the stylus as the cleaner arm swings back. A timing device deenergizes the stylus lowering device after a preselected time interval to lift the stylus away from the cleaning pad.

Abstract: Audio signals recovered from a video disc record are applied to a dual mode decoder matrix via track and hold circuits which mute the audio signals in response to defect indicating signals and player mode control signals. A selected one of the mode control signals is applied to the matrix for causing the matrix to form sum and difference output signals at first and second output terminals thereof when at a first logic level and for causing the matrix to produce identical output signals at the output terminals when at a second logic level. Logic circuitry controls the muting and the matrix operating mode to provide compatibility with monophonic, matrixed two channel (e.g., stereophonic) and un-matrixed two channel (e.g., bilingual) video disc records and suppression of record noise in all operating modes.

Abstract: A video disc player designed to play video disc records having either non compressed monophonic wide band audio signals or video disc records having compressed stereophonic limited band audio signals recorded thereon. The player includes expander circuitry which may be selectively operated as a time invariant amplifier in the absence of stereo audio signals and as an amplifier with a time varying transfer function for expanding the stereo signals. The expander circuit operating mode is controlled by a circuit which detects the presence of a second or stereo sound carrier in the signal recovered from the record being played. Concurrently with the amplifier being rendered time invariant during the playback of monophonic records, electronic filter circuitry is switched into the amplifier circuitry to reduce the monophonic audio bandwidth and effectively increase the resultant audio signal-to-noise ratio.

Abstract: The envelope of an input signal to be expanded is detected and applied via an adaptive filter to the gain control input of a variable gain device which expands the input signal. The adaptive filter provides improved ripple reduction and transient response characteristics and comprises a low pass filter for producing a smoothed control signal and an analog gate for coupling the greater of the smoothed control signal or a further signal to the variable gain device, the further signal being equal to the filter input signal less two predetermined constants. The gate further includes plural current paths selectively enabled for different conditions of the low pass filter input and output signals for augmenting the supply of current to the filter.