Patents by Inventor Dolf Landheer
Dolf Landheer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20040156164Abstract: The use of doped or undoped rare-earth silicates, according to the formula MSixOy wherein M is a rare-earth element, in semiconductor technology is disclosed. In particular, gadolinium silicate as a gate dielectric of a metal-insulating-semiconductor device is disclosed. The insulator of the metal-insulating-semiconductor device is fabricated by exposing a suitably cleaned and terminated surface of a semiconductor substrate to a simultaneous or sequential flux of rare-earth atoms, silicon atoms and oxygen atoms, and annealing the resulting rare-earth containing layer. The use of higher dielectric constant material, such as provided by the invention, reduces the tunneling current through the device, since layers of greater thickness can be used.Type: ApplicationFiled: February 11, 2004Publication date: August 12, 2004Applicant: National Research Council of CanadaInventors: Dolf Landheer, James Gupta
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Patent number: 6700171Abstract: The use of doped or undoped rare-earth silicates, according to the formula MSixOy wherein M is a rare-earth element, in semiconductor technology is disclosed. In particular, gadolinium silicate as a gate dielectric of a metal-insulating-semiconductor device is disclosed. The insulator of the metal-insulating-semiconductor device is fabricated by exposing a suitably cleaned and terminated surface of a semiconductor substrate to a simultaneous or sequential flux of rare-earth atoms, silicon atoms and oxygen atoms, and annealing the resulting rare-earth containing layer. The use of higher dielectric constant material, such as provided by the invention, reduces the tunneling current through the device, since layers of greater thickness can be used.Type: GrantFiled: October 29, 2001Date of Patent: March 2, 2004Assignee: National Research Council of CanadaInventors: Dolf Landheer, James Gupta
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Publication number: 20020050608Abstract: The use of doped or undoped rare-earth silicates, according to the formula MSixOy wherein M is a rare-earth element, in semiconductor technology is disclosed. In particular, gadolinium silicate as a gate dielectric of a metal-insulating-semiconductor device is disclosed. The insulator of the metal-insulating-semiconductor device is fabricated by exposing a suitably cleaned and terminated surface of a semiconductor substrate to a simultaneous or sequential flux of rare-earth atoms, silicon atoms and oxygen atoms, and annealing the resulting rare-earth containing layer. The use of higher dielectric constant material, such as provided by the invention, reduces the tunneling current through the device, since layers of greater thickness can be used.Type: ApplicationFiled: October 29, 2001Publication date: May 2, 2002Inventors: Dolf Landheer, James Gupta
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Patent number: 4745421Abstract: The invention provides a method of making an ionographic cartridge for use with a dielectric coated drum to lay electrostatic images on the drum for subsequent toning. The method includes the steps of making a printed circuit board carrying on one of its faces a plurality of driver electrodes; attaching to the face of the board a dielectric layer sufficient to cover the driver electrodes; providing finger electrodes supported individually between parallel strips of dielectric tapes; and adhering the finger electrodes to the dielectric layer with the finger electrodes straddling the driver electrodes and the tapes spaced to either side of the printed circuit board.Type: GrantFiled: April 17, 1987Date of Patent: May 17, 1988Assignee: Delphax SystemsInventors: Robert S. McCallum, Paul E. Plasschaert, Dolf Landheer, Hemant M. Gandhi
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Patent number: 4679060Abstract: In one of its aspects the invention provides an ionographic print cartridge for use in placing discrete dots of electrostatic charge on a drum to build a latent image for subsequent toning. The print cartridge includes a substrate of a dielectric material having sufficient rigidity to resist deformation during assembly; driver electrodes printed on the substrate and consisting of parallel conductors extending longitudinally and having lead portions terminating at the conductors and extending generally transversely from ends of the conductors for making electrical connections to the driver electrodes. A dielectric layer covers at least the conductors with the conductors at a first side of the layer, and finger electrodes are positioned at the opposite side of the dielectric layer. The finger electrodes define edge structures straddling the driver electrodes and having individual contacts at the sides of the driver electrodes for making electrical connections to the finger electrodes.Type: GrantFiled: November 28, 1984Date of Patent: July 7, 1987Inventors: Robert S. McCallum, Paul E. Plasschaert, Dolf Landheer, Hemant M. Gandhi
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Patent number: 4619515Abstract: This invention provides an electrostatic printing apparatus comprising a rotatable electrostatically chargeable drum and ion deposition means for forming an electrostatic image on the electrostatically chargeable drum, the improvement comprising means for discharging a flow of air along the path of flow extending between the periphery of the electrostatically chargeable drum and the ion discharge means.Type: GrantFiled: March 25, 1985Date of Patent: October 28, 1986Assignee: Delphax SystemsInventors: Andrzej Maczuszenko, Ernest Davison, Brian Otter, Brian F. Whittaker, Christopher Novak, Dolf Landheer
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Patent number: 4595277Abstract: The invention provides an agitator for releasing powder toner through a bottom opening of a hopper. The agitator has a screen for placing over the opening and an element which, when positioned in the hopper, is in contact with the upper surface of the screen. Toner normally bridges the openings in the screen so that there is normally no flow through the screen and the element is operable to brush over the upper surface of the screen to break down the bridging locally, thereby effectively sifting powder toner through the screen. On stopping the element, the toner again bridges the openings and flow of toner stops. The invention also provides a feeder which magnetically transports toner received from the hopper, and an applicator which takes the toner magnetically from the feeder and transports the toner to the point of use.Type: GrantFiled: January 30, 1984Date of Patent: June 17, 1986Inventors: Andrzej Maczuszenko, Sotos M. Theodoulou, Kenneth L. Hurley, Dolf Landheer
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Patent number: 4516847Abstract: Apparatus is provided for printing on a receptor such as paper. An electrostatic image is formed on a dielectric-coated drum in a controlled environment to minimize the creation of chemical contaminants. The image is then toned by wiping toner over the image from a toner delivery system which includes a mouth shaped to cause a vortex in the toner to improve toner flow. After toning the image is transferred to the receptor under pressure from a roller which is skewed with reference to the drum. The pressure in the nip is sufficient to also cause the toner to be fused to the receptor. An image eraser is also provided in the controlled environment.Type: GrantFiled: December 3, 1982Date of Patent: May 14, 1985Assignee: Delphax SystemsInventors: Andrzej Maczuszenko, Ernest Davison, Brian Otter, Brian F. Whittaker, Christopher Novak, Dolf Landheer
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Patent number: 4514781Abstract: The invention provides a support member which carries at least one axially aligned corona electrode, and a conductive biasing member wrapped around both the support member and the electrode. The biasing member is preferably a wire wrapped about the support and electrode to form a coil and preferably there are four electrodes. A conductor extends the length of the coil to ensure continuity should the biasing member fail locally.Type: GrantFiled: June 10, 1983Date of Patent: April 30, 1985Inventors: Paul E. Plasschaert, Dolf Landheer, Harold W. Cobb
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Patent number: 4254424Abstract: The present disclosure is directed to electrostatic recording devices wherein a latent electrostatic image is recorded on a dielectric coated sheet by a stylus array spaced apart from the sheet to form an ionization gap. There is now taught a means to accurately establish the distance between the recording stylus and the dielectric surface upon which the latent image is created. A dielectric sheet containing a conductive layer is passed over a fixed recording head containing an array of styli. The fixed recording head is provided with a source of fliuid which maintains positive pressure in a cavity with the recording head, which cavity has outlets facing the dielectric sheet passing over the head. The length of the gap between the dielectric sheet and the recording head is maintained by the fluid pressure emanating from the head.Type: GrantFiled: June 4, 1979Date of Patent: March 3, 1981Assignee: Xerox CorporationInventors: Dolf Landheer, Shy-Shung Hwang, Charles Nesta, Gino F. Squassoni