Arthur E Fleek

US Patent:

58752129, Feb 23, 1999

Filed:

Oct 26, 1994

Appl. No.:

8/329363

Inventors:

Arthur E. Fleek - Cary NC
William O. Camp - Chapel Hill NC
Gary M. Warchocki - Owega NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04L 2718

US Classification:

375329

Abstract:

A phase shift modulator at the transmitter has a control input connected to a binary signal source. A high frequency carrier signal is applied to a carrier signal input of the modulator. The modulated carrier signal is transmitted to a receiver where it is mixed with a local oscillator frequency. At the receiver, a modulated signal is amplified by a limit amplifier to form the received signal into square wave pulses of a uniform height. The demodulator detects when the spacing between the edges of the square wave signal change in response to the phase shift modulation at the transmitter. When the spacing between the edges of the square wave IF signal is detected to be shorter than the normal spacing for a steady IF signal with no modulation, this signifies a first binary value. A longer than normal spacing between the edges of the square wave IF signal signifies a second binary value. Frequency drift compensation circuits are disclosed to overcome frequency variations in the carrier and the local oscillator.

US Patent:

55330690, Jul 2, 1996

Filed:

Oct 26, 1994

Appl. No.:

8/329362

Inventors:

Arthur E. Fleek - Cary NC
William O. Camp - Chapel Hill NC
Gary M. Warchocki - Owego NY
Michael J. Bracco - Raleigh NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04L 2706

US Classification:

375344

Abstract:

A carrier sensing circuit coupled to a receiving amplifier, measures the frequency of a phase shift modulated carrier signal by counting a predetermined number of the pulses for a measured interval whose duration is determined by counting a first clock count value. A demodulator coupled to the amplifier, detects when the spacing between the edges of the square wave pulses changes in response to the phase shift modulation. The demodulator measures first intervals between consecutive rising edges of the received signal, by counting clock pulses for a second selected interval whose duration is determined by a second selected count value. The demodulator further measures second intervals between consecutive falling edges of the received signal by counting clock pulses for a third selected interval whose duration is determined by a third selected count value. A compensating circuit coupled to the carrier sensing circuit and to the demodulator, compensates for frequency drift in the carrier signal or in the local oscillator by adjusting the second selected count value and the third selected count value, using the first clock count value.

US Patent:

43354602, Jun 15, 1982

Filed:

Jan 28, 1980

Appl. No.:

6/115841

Inventors:

Richard D. Bolcavage - Kirkwood NY
Armand J. Ferraro - Endicott NY
Arthur E. Fleek - Cary NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1110

US Classification:

371 49

Abstract:

A printer control system for a belt printer has an arrangement for checking print hammer operating circuits by comparing a real time actual parity of the circuits with a precalculated expected parity. Prior to printing, a microprocessor calculates expected parity bytes for each subscan for storage in a storage device along with the print position fire data used for selecting the operating circuits to be activated in the related subscans. An actual parity byte is generated on a real time basis by ODD/EVEN parity circuits associated with groups of operating circuits for comparison with a composite parity byte generated each subscan by the microprocessor. The composite parity byte is generated by combining the expected parity bytes from the storage device for several successive subscans. The composite parity byte is updated each subscan by a process of subtracting the initial expected parity byte and adding a new subscan expected parity byte. Comparison is made when all the activating circuits are in stable condition.

US Patent:

42730414, Jun 16, 1981

Filed:

Jan 28, 1980

Appl. No.:

6/115856

Inventors:

Richard D. Bolcavage - Kirkwood NY
Armand J. Ferraro - Endicott NY
Arthur E. Fleek - Cary NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

B41J 120

US Classification:

101 9314

Abstract:

A belt printer control system for attachment to a host system has a first microprocessor connected by a dedicated bus to the host system and control elements operable to perform carriage control, belt drive, and ribbon drive operations of the printer mechanism. A second microprocessor is connected by a dedicated bus structure to controls for operating the print hammers. A common RAM is accessed by the two microprocessors through a common bus structure. The first microprocessor passes control and print information to the RAM for use by the second microprocessor in building print algorithm tables in the RAM for use by the second microprocessor to operate the print hammers. Communication between the microprocessors is done through control information stored by the microprocessors in the common RAM. Storing printing information and building of tables and controlling printing and nonprinting operations of the print mechanism are done concurrently.

US Patent:

58675337, Feb 2, 1999

Filed:

Aug 14, 1996

Appl. No.:

8/702412

Inventors:

Arthur E. Fleek - Cary NC
William O. Camp - Chapel Hill NC
Michael J. Bracco - Raleigh NC

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04L 12413
H04L 2718

US Classification:

375279

Abstract:

An apparatus and a method for detecting a carrier signal of a phase shift keyed modulated signal. A first counter circuit generates a plurality of counts, with each count being a number of cycles of a reference frequency signal occurring between two consecutive rising edges of an intermediate frequency signal. A comparison circuit compares a first count of reference frequency cycles to a second count of reference frequency cycles when a difference between an initial count of reference frequency cycles and a first predetermined number is less than a second predetermined number. The first predetermined number represents a time period of one cycle of the nominal center frequency, and the first count and the second count respectively represent time periods of first and second cycles of a pair of consecutive cycles of the intermediate frequency signal. The comparison circuit generates a difference signal when a difference between the first count and the second count is less than a third predetermined number. A second counter circuit counts cycles of the intermediate frequency signal and generates a carrier detect signal when a count of the intermediate frequency signal cycles equals a fourth predetermined number.

US Patent:

42756537, Jun 30, 1981

Filed:

Jan 28, 1980

Appl. No.:

6/115855

Inventors:

Richard D. Bolcavage - Kirkwood NY
Arthur E. Fleek - Cary NC
Mitchell P. Marcus - Boca Raton FL

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

B41J 120

US Classification:

101 9314

Abstract:

A printer system comprising a belt printer mechanism controlled by a stored program digital microprocessor to print lines of data on a print medium. Selective operation of a linear array of print hammers, paper feeding, data conversion and arranging in scan/subscan order are performed by the microprocessor. The fire data for operating hammers is precalculated and arranged in scan/subscan order during the print medium feeding interval with printing occurring immediately at the first print scan after print medium motion in which one or more desired characters become aligned with print hammers. An indirect addressing technique which eliminates sorting is used to arrange the print position fire data in scan/subscan order.

US Patent:

44481233, May 15, 1984

Filed:

Jun 30, 1982

Appl. No.:

6/394054

Inventors:

Arthur E. Fleek - Cary NC
Samuel C. Tseng - Pleasantville NY

Assignee:

International Business Machines - Armonk NY

International Classification:

B41J 312
B41J 120

US Classification:

101 9304

Abstract:

A variable speed printing (VSP) adaptor for a dot matrix printer which includes a monitoring means having a plurality of devices each capable of assuming one of two states. The monitoring means monitors the state of the pattern data to be printed, and, in the preferred embodiment, the monitoring means comprises a counter which is preset with a number equal to the number of column scans with a dot print line. The pattern data to be printed is scanned in a forward direction, i. e. , in the normal printing direction starting at the first print position and the count in the counter is decremented one count for each column data scanned. During the time interval between when this data is latched and the actual hammer actuation, the pattern data is scanned in the backward direction starting at the last print position. Each time the column data for a backward scan is zero, i. e. , no dot to be printed, prior to sensing a non-zero column, the count in the counter is decremented one count.

US Patent:

55330258, Jul 2, 1996

Filed:

Sep 26, 1994

Appl. No.:

8/313516

Inventors:

Arthur E. Fleek - Cary NC
Richard O. LaMaire - Yorktown Heights NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04J 302

US Classification:

370 852

Abstract:

A method for use in a single cell of a wireless communication system of the type having a leader station that coordinates communication among a plurality of remote stations that are in the cell. The method applies to systems that use slow frequency-hopping radios and a Carrier Sense Multiple Access (CSMA) type protocol. In this context, the method allows a remote station to initially acquire the frequency-hopping pattern and time base of the leader station and to maintain frequency synchronization in the face of control information loss due to radio transmission effects (e. g. , interference, noise or multipath fading). In the acquisition phase, the remote station actively generates probe messages that are sent to the leader station so as to rapidly achieve frequency synchronization with the leader station.