US4368457A — Analog-to-digital converter

Claim 1

Independent Claim 108 words

An analog-to-digital converter comprising a storage means connected to an input terminal and storing a signal corresponding to the analog input signal, a discharging means connected to the output terminal of said storage means and discharging said stored signal, and a counter means for counting the number of clock pulses till the time at which the voltage at said output terminal of said storage means reaches a certain detection level during discharging; wherein said analog-to-digital converter further comprises a constant DC bias voltage supply means connected in series with said storage means to shift the voltage at said output terminal of said storage means above said detection level.

Claim 2

Dependent Claim 108 words

An analog-to-digital converter comprising a storage means connected to an input terminal and storing a signal corresponding to the analog input signal, a discharging means connected to the output terminal of said storage means and discharging said stored signal, and a counter means for counting the number of clock pulses till the time at which the voltage at said output terminal of said storage means reaches a certain detection level during discharging; wherein said analog-to-digital converter further comprises a constant DC bias voltage supply means connected in series with said storage means to shift the voltage at said output terminal of said storage means above said detection level.

Claim 3

Dependent Claim 69 words

An analog-to-digital converter according to claim 1; wherein said storage means comprises a first switch one end of which is connected to said input terminal and a capacitive element the one end of which is connected to the other end of said first switch and the other end of which is connected to the earth; said DC bias voltage supply means being connected in series with said capacitive element.

Claim 4

Dependent Claim 23 words

An analog-to-digital converter according to claim 1, wherein said discharging means comprises a series connection of a resistance element and a second switch.

Claim 5

Dependent Claim 17 words

An analog-to-digital converter according to claim 2, wherein said DC bias voltage supply means comprises an inverter.

Claim 6

Dependent Claim 35 words

An analog-to-digital converter according to claim 2, wherein said DC bias voltage supply means comprises a parallel circuit of a third switch and a series connection of a fourth switch and a bias voltage source.

Claim 7

Dependent Claim 128 words

An analog-to-digital converter comprising a storage means for storing an analog input signal voltage applied at an input terminal, a discharging means connected to the output terminal of said storage means and discharging said analog input signal voltage stored in said storage means, a level detection means for detecting the time at which the voltage at the output terminal of said storage means reaches a detection level voltage, and a counter for counting the number of clock pulses from the beginning of discharging to the detection times of said level detection means; wherein said analog-to-digital converter further comprises a constant DC bias voltage supply means connected in series with said storage means to shift the voltage at said output terminal of said storage means above said detection level.

Claim 8

Dependent Claim 128 words

An analog-to-digital converter comprising a storage means for storing an analog input signal voltage applied at an input terminal, a discharging means connected to the output terminal of said storage means and discharging said analog input signal voltage stored in said storage means, a level detection means for detecting the time at which the voltage at the output terminal of said storage means reaches a detection level voltage, and a counter for counting the number of clock pulses from the beginning of discharging to the detection times of said level detection means; wherein said analog-to-digital converter further comprises a constant DC bias voltage supply means connected in series with said storage means to shift the voltage at said output terminal of said storage means above said detection level.

Claim 9

Dependent Claim 18 words

An analog-to-digital converter according to claim 6, wherein said level detection means comprises a multistage connection of inverters.

Claim 10

Dependent Claim 86 words

An analog-to-digital converter according to claim 7, wherein said storage means comprises a first switch one end of which is connected to said input terminal and a capacitive element the one end of which is connected to the other end of said first switch and the other end of which is connected to the earth; said discharging means comprising a series circuit of a discharging circuit and a second switch inserted between the connection point of said first switch and said capacitive element and the earth.

Claim 11

Dependent Claim 42 words

An analog-to-digital converter according to claim 8, wherein said DC bias voltage supply means comprises a parallel circuit of a third switch and a series connection of a fourth switch and a voltage source, and connected in series with said capacitive element.

Claim 12

Dependent Claim 18 words

An analog-to-digital converter according to claim 9, wherein said first, second, third and fourth switches comprise an MOSFET.

Claim 13

Dependent Claim 13 words

An analog-to-digital converter according to claim 7, wherein said inverter comprises an MOSFET.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-01-10	1986-07-12	1987-01-11	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-01-10	1990-07-12	1991-01-11	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-01-10	1994-07-12	1995-01-11	$7700.00	Window Closed / Lapsed

Analog-to-digital converter

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