Matrix amplifier

Claim 2

In a television receiver of the type having a cathode-ray tube image reproducer, a source of luminance signals, and a source of chrominance signals, both derived from a received television transmission, a matrix amplifier stage comprising: an amplifier device having input, output and common electrodes; means for supplying operating power to said amplifier device; means for concurrently applying luminance and chrominance signals to respective input and common electrodes of said amplifier device; a first voltage divider having first and second end terminals and an adjustable tap, said first end terminal being coupled to said output electrode, and said tap being direct-current coupled to said image reproducer; means for establishing a predetermined voltage level at said output electrode corresponding to a reference beam-current condition in said image reproducer; and means for applying to said second end terminal of said voltage divider a voltage substantially equal to said predetermined voltage level at said output electrode to permit said tap to be varied without varying the DC level applied to said image reproducer.

Claim 3

A matrix amplifier stage as described in claim 1, wherein said means for applying said voltage to said second end terminal of said voltage divider comprises a second voltage divider having a first end terminal for receiving unidirectional operating current, a second end terminal maintained at a reference potential, and a tap coupled to said second end terminal of said first voltage divider.

Claim 4

A matrix amplifier stage as described in claim 2, wherein said second voltage divider has a second tap located between said first tap and said second end terminal and coupled to the input electrode of said amplifier device, for simultaneously establishing a degenerative feedback path between said output and input electrodes of said device for stabilizing both the direct-current and alternating-current operation thereof and for providing operating bias to said input electrode.

Claim 5

A matrix amplifier stage as described in claim 3, wherein said second voltage divider has a third tap coupled to said chrominance signal source for applying said chrominance signal to said input electrode.

Claim 6

A matrix amplifier stage as described in claim 4, wherein said third tap is located between said second tap and said second end terminal.

Claim 7

A matrix amplifier stage as described in claim 3, wherein said stage comprises: an additional amplifier device also having input, output and common electrodes; means for supplying operating power to said additional amplifier device; an additional voltage divider having first and second end terminals anD an adjustable tap, its first end terminal being coupled to the output electrode of said additional amplifier device, and its tap being direct-current coupled to said image reproducer; means for establishing a predetermined voltage level at the output electrode of said additional amplifier device corresponding to a reference beam-current condition in said image reproducer; means comprising a further voltage divider having a first end terminal for receiving unidirectional operating current, a second end terminal maintained at a reverence potential, a first tap coupled to the second end terminal of said additional voltage divider, and a second tap located between such first tap and such second end terminal and coupled to the input electrode of said additional amplifier device, for applying to the remaining end terminal of said additional voltage divider a voltage substantially equal to said predetermined voltage level at the output electrode of said additional amplifier device, and for simultaneously establishing a degenerative feedback path between the output and input electrodes of said additional amplifier device for stabilizing both the direct-current and alternating-current operation thereof and for providing operating bias to the input electrode of said additional device; and means including a frequency selective network interposed between said base electrodes of said amplifier devices and said reference potential for establishing a predetermined frequency response characteristic for said degenerative feedback paths.

Claim 8

A matrix amplifier stage as described in claim 6 wherein said frequency selective network comprises an inductor having one end terminal maintained at a reference potential, and first and second capacitors coupled from the input electrodes of respective ones of said amplifier devices to the remaining end terminal of said inductor.

Claim 9

A matrix amplifier stage as described in claim 7, wherein said inductor and said capacitors are series resonant in the range of 2 to 3 mHz. to accentuate high frequency luminance signal information, and said inductor is self-resonant at frequencies between 40 and 50 MHz. to reduce undesired radiation.

Claim 10

A matrix amplifier as described in claim 1, wherein said predetermined voltage level corresponds to the cutoff point of the electron beam in said image reproducer.

Claim 11

A matrix amplifier as described in claim 1, wherein said amplifier device is a transistor having input-base, output-collector and common emitter electrodes and wherein said means for establishing said predetermined voltage level comprises means for establishing a predetermined emitter-base bias on said amplifier device.

Claim 12

In a matrix amplifier stage for combining a received luminance signal with a plurality of color-difference signals to form color control signals for a color image reproducer: first and second amplifier devices each having input, output and common electrodes; means for applying said luminance signal to said common electrodes and said color-difference signals to respective ones of said input electrodes; means for applying negative feedback from the output electrodes of the first and second amplifiers to the input electrodes of the first and second amplifiers; and means including a frequency selective network comprising a common inductive element coupled between the input electrodes of said amplifier devices and a reference potential for establishing a predetermined frequency response characteristic in each of said amplifier devices.

Claim 13

In a matrix amplifier stage for combining a received luminance signal with a plurality of color-difference signals to form color control signals for a color image reproducer: first and second amplifier devices each having input, output and common electrodes; means for applying said luminance signal to said common electrodes and said color-difference signals to respective ones of said input electrodes; means for applying negative feedback from the output electrodes of the first and second amplifiers to the input electrodes of the first and second amplifiers; and means including a frequency selective network comprising a common inductive element coupled between the input electrodes of said amplifier devices and a reference potential for establishing a predetermined frequency response characteristic in each of said amplifier devices.

Claim 14

A matrix amplifier as described in claim 11, wherein said frequency selective network comprises an inductor having one end terminal maintained at a reference potential and one end terminal coupled by first and second capacitors to the input electrodes of respective ones of said amplifier devices.

Claim 15

A matrix amplifier as described in claim 12, wherein said inductor and said capacitors are series resonant in the range of 2 to 3 MHz. to accentuate high frequency luminance signal information, and said inductor is self-resonant at frequencies between 40 and 50 MHz. to reduce undesired radiation.