Abstract: A precoded N-level HDTV digital video characterized by a sampling rate fs substantially equal to 3/2 the NTSC color subcarrier frequency is modulated for transmission on a carrier signal having a frequency substantially mid-way between the picture carrier and color subcarrier of an NTSC co-channel. The received signal is detected by a synchronous detector in response to a regenerated carrier signal and interfering NTSC beat components in the output of the detector are attenuated by a comb filter having a notch at fs/3. The output of the comb filter comprises an M-level signal, where M is greater than N, which is converted to an N-level signal corresponding to the demodulated video signal.

Abstract: Apparatus for converting a signal having a substantially continuous frequency spectrum to a signal having its energy concentrated at multiples of the line frequency of a video signal, includes circuitry for apportioning the signal into two intermediate signals including, in part, mutually exclusive portions of the original signal and inverting the polarity of portions of the signal. The two intermediate signals are thereafter used to quadrature phase modulate a carrier of multiple line frequency to generate a signal for combining with a video signal for transmission.

Abstract: A high-definition television system in which a production signal is spatiotemporally filtered to remove frequency components and remaining components are transmitted over a channel. In various aspects, the filter produces a generally diamond-shaped frequency response in each of the spatial and spatiotemporal planes; the components selected for transmission are selected in accordance with the amount of motion in the image; the remaining components of image data are transmitted using double-sideband quadrature modulation; a high frequency component of the production signal shares the channel with additional data; and when the image data is transmitted using double-sideband quadrature modulation, baseband signals are derived from closely related areas of the image.

Abstract: An adaptive rounder for avoiding truncation errors for digital video signal has a dither source that is modified by the bits of an integer portion of an input digital signal corresponding to the video signal. A dither signal from the dither source has a number of bits equal to a fractional portion of the input digital signal. The dither signal is added to the input digital signal and the result is truncated to produce an output digital signal having a number of bits equal to the integer portion.

Abstract: The relative gain and/or delay of two signal transmission channels may be measured by impressing on each channel a repetitive signal comprising a burst packet. The burst packets of the signals applied to the channels are of constant, but different, frequencies, and their amplitudes are related in predetermined manner. The two burst packets are timed to have a predetermined phase relationship at a selected time during the packets. The output signals of the two channels are additively combined, and a determination is made as to at least one of (a) the amplitude of the combined signal at a turning point in the amplitude of the signal envelope and (b) the time relative to the selected time at which a turning point in the amplitude of the signal envelope occurs.

Abstract: The luminance and chrominance signals of a PAL or SECAM composite video signal are separated by means of a method comprising the following steps:sampling and digitizing the composite video signal;determination of a luminance signal and a chrominance signal by means of a first processing channel, from the digital sample of the current point of the image, from a previous sample corresponding to the current point located on the line in the previous field which is spatially positioned in the image immediately beneath the current line, from the luminance signal values already determined in a spatiotemporal neighborhood of the current point and in accordance with an analysis of the local spatiotemporal context of the current point;determination of a luminance signal and a chrominance signal by means of a second processing channel by applying the digital composite signal to the input respectively of a luminance filter and a chrominance filter;selection of the luminance and chrominance signals which are present at th

Abstract: A video stream processing system frame buffer controller for controlling external dynamic random access memory (DRAM) of a frame buffer and interfacing to the video stream processing signal bus. The frame buffer controller has four interfaces, video input interface, video output interface, memory interface and processor interface. The circuit can input image data from a camera and store the frames in external DRAM. The circuit provides for external processor access to pixels in the frame buffer and for output of the frame or portions of the frame, as well as output of frames in a format of CRT display and external DRAM refresh.

Abstract: An apparatus, including a lookup table memory, for gamma correcting a digital video signal based on the assumption that for small gamma, gamma correction is a linear function so that for a digital video input signal value x a gamma correction value d to be added to x can be calculated as a function of an opertor selected variable a according to the formulae:d=10.multidot.0.multidot.(x-x.sup.1.10)ord=10.multidot.9.multidot.(x-x.sup..90 ).

Abstract: A fully compatible high definition signal, which can still be received with conventional resolution by conventional TV receivers without auxiliary apparatus is provided by the present invention. One TV channel carries the conventional TV signal while high frequency luminance and chrominance information is provided in a second TV channel. The baseband signal containing the high frequency components is derived from the lower sideband output of a product modulator whose inputs are taken from an anti-alias filtered (camera) source of wideband luminance information and a local oscillator whose frequency is a multiple of the conventional chrominance subcarrier frequency embedded in the conventional baseband signal for the other channel.

Abstract: A portable electric power tool incorporates in conjunction with its double-pole main switch mechanism (11) a separate carrier member (10) which carries two pairs of terminals (20; 41) for the attachment of the main electric leads and the motor stator leads. Four pairs of complementary connectors (23, 24, 32, 33; 48) are also provided, the two connectors of each pair being mounted one on the carrier member (10) and the other on the switch mechanism (11) and the four connectors on the carrier member (10) are respectively connected to the terminals (20; 41). The carrier member (10) is appropriately located in the tool and has two posts (44) which become engaged in apertures (45) in the body of the switch mechanism (11) as the mechanism (11) is placed in position. The connectors (23, 24, 32, 33; 48) of each pair are so disposed that the act of positioning the switch mechanism (11) in this way brings the connectors (23, 24, 32, 33; 48) of each of the four pairs into engagement.

Abstract: The invention relates to a bi-stable (toggle) mechanism for a vehicle anti-theft device comprising a lever 20 pivotally mounted by a shaft 21, the said lever being subject to the action of a spring 22 and movable from one stable position through a center position to a second stable position.In the mechanism according to the invention, the said spring 22 consists of a hairpin type spring of which one end 26 is connected to one end of the said lever 20 and the other end 23 mounted so as to pivot at a fixed point 24. The distance between the ends 23,26 of the spring 22 when the lever 20 is in either stable position is greater than the distance between the ends when the lever 20 is at its center position whereby the spring becomes more compressed as the lever approaches the center position where the lever is unstable. The distance between the two ends of the hairpin spring may be less than half that length of the lever which is included between its shaft 21 and the point 24 at which the hairpin spring is located.

Abstract: Line indicating apparatus is provided which is capable of suspending an elongated line indicator whereby it is movable in a direction substantially perpendicular to its linear axis, and is rotatable around a second axis which is angularly disposed with respect to the linear axis and the said direction of movement. A plurality of the basic apparatus may be arranged in a superimposed relationship, and the resultant plurality of superimposed line indicators may be individually moved and/or rotated to positions wherein they are angularly disposed with respect to each other. Preferably, the line indicators are movable and rotatable in closely adjacent fixed planes so that a substantially distortion-free image thereof may be produced and visually displayed.The line indicating apparatus is especially useful in navigational charting or plotting, and in navigational devices pertaining thereto.

Abstract: The invention relates to a bi-stable (toggle) mechanism for a vehicle anti-theft device comprising a lever 5 pivotally mounted by a shaft 6, the said lever being subject to the action of a spring 10 and movable from one stable position through a center position to a second stable position.In the mechanism according to the invention, the said spring 10 consists of a hairpin type spring of which one end 9 is connected to one end of the said lever 10 and the other end 11 mounted so as to pivot at a fixed point 12. The distance between the ends 9, 11 of the spring 10 when the lever 5 is in either stable position is greater than the distance between the point 12 of location of the spring 10 and the point of engagement of the spring end 9 with the lever end when the lever 5 is at its center position whereby the spring becomes more compressed as the lever approaches the center position where the lever is unstable.

Abstract: A gear pump comprising a driving and a driven gear, pairs of successive teeth of at least one gear each having a cut-out allowing a proportion of slip, the cut-outs each extending to the root of the tooth and the cut-outs in successive teeth being in axially differently located positions.

Abstract: A flow control valve having a valve chamber which is adapted to receive fluid under pressure and which comprises a valve member having a surface with a groove therein and an outlet passage terminating at one end in a port in the groove. A resilient element is provided in the valve chamber in confronting relationship with the groove. The resilient element has an aperture in registry with the groove. The resilient element and the valve member are mounted for relative movement so as to change the relative position of the groove and the aperture, and this permits the manual selection of the flow rate. The pressure in the valve chamber urges the resilient element into the groove an amount which is dependent on the magnitude of the pressure. In this way the selected flow rate is made independent of inlet pressure fluctuations.