Henry A Lewis

US Patent:

46774823, Jun 30, 1987

Filed:

Dec 31, 1985

Appl. No.:

6/815449

Inventors:

Henry G. Lewis - Hamilton Square NJ

Assignee:

RCA Corporation - Princeton NJ

International Classification:

H04N 701

US Classification:

358140

Abstract:

The line rate of a video input signal is doubled for display in progressive scan fashion by dual mode processor which generates added lines for the display by interpolation when displaying normal television pictures and by replication (repeating lines) when displaying characters. The processor mode is automatically controlled by an image analyzer which identifies fields of text by counting "major" transitions of the video input signal occurring within a field and comparing the count with a threshold value. Errors in identification are minimized by a further counter which integrates the field count and a hysteresis detector which controls the processor operating mode in accordance with high and low limits of the integrated field count.

US Patent:

45660280, Jan 21, 1986

Filed:

May 25, 1983

Appl. No.:

6/498102

Inventors:

Henry G. Lewis - Hamilton Square NJ
Thomas V. Bolger - Merchantville NJ

Assignee:

RCA Corporation - Princeton NJ

International Classification:

H04N 1104

US Classification:

358 21R

Abstract:

In a digital signal processing system, an analog-to-digital converter producing digital representations of an analog signal is dithered to increase its apparent quantizing resolution. Certain processing of the digital signals, however, can result in the loss of the dither information, because of either the form of digital filtering employed or the number of bits of the digital signals processed. To avoid the effects of such loss, the least significant bit of the digital signals is delayed and is applied to an analog output device to reintroduce a dither signal thereat having a magnitude substantially equivalent to that of the lost bit. The present invention is useful in processing digital television signals in a television receiver having a digital signal processing section.

US Patent:

46986804, Oct 6, 1987

Filed:

Dec 24, 1985

Appl. No.:

6/813396

Inventors:

Henry G. Lewis - Hamilton Square NJ

Assignee:

RCA Corporation - Princeton NJ

International Classification:

H04N 514
H04N 521

US Classification:

358166

Abstract:

A television deghosting system includes an IIR filter having programmable filter coefficients which processes the input signals to remove ghost signal components. The IIR filter may be reconfigured as an FIR filter, having its coefficient and delay values changed to operate as a matched correlation filter. In this mode the filter is used to correlate a training signal to determine the relative delays of ghost signals with respect to the direct signal. The training signal used is the sum of the squared differentials of the in-phase and quadrature-phase components of the video IF signal during an interval defined by the leading edge of the vertical sync pulse and the first equalization pulse.

US Patent:

47033576, Oct 27, 1987

Filed:

Dec 24, 1985

Appl. No.:

6/813256

Inventors:

Henry G. Lewis - Hamilton Square NJ

Assignee:

RCA Corporation - Princeton NJ

International Classification:

H04N 514
H04N 538

US Classification:

358166

Abstract:

An adaptive television deghosting system operates on modulated video signals including a direct signal component and one or more ghost signal components. The system uses synchronously demodulated in-phase and quadrature-phase baseband video signals as the respective real and imaginary input signals to a complex IIR filter. The filter coefficients are developed adaptively from preset initial values using the signals provided by the filter during a training interval. The training interval includes the interval between the leading edge of the vertical sync pulse and the first serration pulse of each field. The filtered training signals are subtracted from a sync-tip reference value to develop a signal which is proportional to the error in the filter coefficient values. The error signal values corresponding to ghost signals are multiplied by the complex conjugate of the training signal values which represent the analogous sampling points of the direct signal. The values produced by this multiplication operation are scaled by an adaptation constant and accumulated to produce the filter coefficients which are used to cancel the ghost signals.

US Patent:

44159188, Nov 15, 1983

Filed:

Aug 31, 1981

Appl. No.:

6/297556

Inventors:

Henry G. Lewis - Hamilton Square NJ

Assignee:

RCA Corporation - New York NY

International Classification:

H04N 950

US Classification:

358 23

Abstract:

A digital filter arrangement is provided which both demodulates and filters the color mixture signals in a television receiver. Samples of a digital chrominance signal are clocked into first and second registers such that the first register is loaded with samples of a first color mixture signal and the second register contains samples of a second color mixture signal. Output taps are connected between various ones of the stages of the first and second registers and weighting function circuits. The weighting function circuits associated with each register are in turn coupled to respective ladder networks of adders, which combine the weighted signals samples so as to exhibit, at an output stage adder, a lowpass response characteristic which is appropriate for the respective color mixture signal. The two digital registers are aligned in time in accordance with their respective peak impulse response characteristic to product filtered color mixture signals in a proper timed relationship.

US Patent:

43957293, Jul 26, 1983

Filed:

Aug 31, 1981

Appl. No.:

6/298255

Inventors:

Henry G. Lewis - Hamilton Square NJ

Assignee:

RCA Corporation - New York NY

International Classification:

H04N 946
H04N 521

US Classification:

358 21R

Abstract:

A digital output tapped filter is provided in which the filtered output signals are latched into a first latch circuit by the clock signal which clocks the serial shift register. Output signals are thereby held in the register during the time that new data values from the shift register are propagating through the adder tree and weighting function circuits. By the time that the clock signal again clocks the shift register, the filter output signal has settled, and can again be latched into the latch circuit. The signals at the output of the latch circuit are thus immunized from signal ripple. A second latch circuit is coupled to the output of the first latch circuit, and is clocked by the same clock signal as the first latch circuit. Consecutively produced filtered data words are thereby held in the latches, and the latched signals of N bits are applied to inputs of an N bit adder. The N bit adder produces an output signal of N+1 bits.

US Patent:

44633718, Jul 31, 1984

Filed:

May 17, 1983

Appl. No.:

6/493805

Inventors:

Henry G. Lewis - Hamilton Square NJ

Assignee:

RCA Corporation - New York NY

International Classification:

H04N 504

US Classification:

358 13

Abstract:

A digital signal processing system of a television receiver includes a digital to analog converter for converting an analog television signal to representative digital samples at times corresponding to pulses of a sampling signal. Clock signal generating is provided to selectively shift the phase of the sampling signal from that corresponding to the -(B-Y) and (R-Y) color reference vectors to that corresponding to the I and Q, color reference vectors as modified by a tint adjustment, at a time during each horizontal scanning interval before beginning of the image interval. In this manner, digital -(B-Y) chrominance samples corresponding to the peaks of the color burst signal component are made available for digital automatic chrominance gain control and digital I and Q chrominance samples are made available for digital color demodulation.

US Patent:

46880968, Aug 18, 1987

Filed:

Jun 25, 1986

Appl. No.:

6/878260

Inventors:

Edward R. Campbell - Tabernacle NJ
Henry G. Lewis - Hamilton Square NJ

Assignee:

RCA Corporation - Princeton NJ

International Classification:

H04N 521

US Classification:

358167

Abstract:

A television receiver which includes an automatic deghosting system synchronously demodulates IF television signals to generate baseband signals representing the in-phase and quadrature phase modulation components of the IF signals. A signal representing the phase difference between the carrier of the signal as broadcast and the carrier of the received signal, which may include ghosts, is generated from the in-phase and quadrature signals. This signal is applied to circuitry which develops signals proportional to the sine and cosine of the phase angle separating the broadcast carrier phase and the received carrier phase. The demodulated in-phase and quadrature phase baseband signals are multiplied by the sine and cosine signals in a complex multiplier to correct distortion resulting from the synchronous demodulation using the carrier of the received signal.