Dynamics Research Corporation

Other

Lowell E Thomas

Luke R Volpe, Jr

Luke Volpe

A tool for selectively compressing and expanding work, the tool comprising a handle including bar holders and at least two slidable bars having work engaging surfaces at ends thereof both of which are slidably received in a separate one of the bar holders and both being adapted to be selectively fixed therein whereby at least one of the slidable bars is adapted to be reversibly received in one of the bar holders of the handle.

Compression and expansion tool

An edge-type printhead and method of fabricating the same, eliminates the need for precision grinding, lapping, and polishing of a substrate, avoids the need for precision etching of electrode patterns, avoids the use of highly refined etchable thick film pastes, and avoids the need for precision glaze application in the construction thereof. Contact pads are provided on the printhead writing surface. The contact pads facilitate accurately and inexpensively delineated resistor lengths, provide resistor current spreading for full dot width printing and control resistor row straightness. Contact pads permit the use of standard wet or chemical etching with wide spacing between electrodes while facilitating full width printed dots with narrow spacing. The contact pads are applied to the writing edge after the edge-type substrate is laminated, sectioned and the writing surface is polished.

Edge-type printhead with contact pads

A true edge thermal printhead and method of fabrication wherein the printhead infrastructure is formed by thick film techniques and the individual laminations are formed in a predetermined order. The printhead infrastructure includes a dielectric substrate, a common electrode layer, a high temperature glaze, an electrode pattern, a low temperature glaze and a plurality of resistive heating elements formed on the edge of the infrastructure and interconnected to the electrode pattern and the common electrode layer. The common electrode layer is a unitary sheet of refractory conductive material that is compatible with the high firing temperatures required for the high temperature glaze, and includes multiple ground taps. The fine image electrode pattern is compatible with the reduced firing temperature of the low temperature glaze such that gold pastes may be efficaciously utilized in the formation of the electrode pattern. Driver chips for activating the resistive heating elements are mounted in the printhead infrastructure to enhance printhead performance. Thermistors may be mounted on the glaze and/or substrate to monitor printhead temperature.

True edge thermal printhead

A thermal print head is provided having a substrate with an arcuate edge ground to a selected radius upon which a layer of glaze is deposited and precision ground. Resistive film is patterned onto the glaze and conductive film is applied in electrical connection therewith.

Arcuate edge thermal print head

A modular thermal print head and method of fabricating same including a first member having at least one surface on which is arranged an array of electrodes, and a second member mounted in spaced relationship to the first member and having at least one surface on which is disposed a single conductor element. A thermal printing element having an array of electrically resistive members terminated at one end by conductor pads arranged in an array, and proximate a second end to a common conductive member is provided. The thermal printing element is disposed between the first and second members with its array of conductor pads in contact with the array of electrodes on the first member, and its common conductive member in contact with the single conductor element on the second member. Selected portions of the thermal printing element may be energized to produce thermal printing energy.

Modular thermal print head and method of fabrication

A large-scale printhead is made up of rows of styli patterned onto thin glass substrates sandwiched together between rugged support substrates, in which a series of thin glass substrate sections are internally butted one to the other. Fabrication of multiple rows of elements is accomplished by stacking the delicate styli-bearing substrates on an associated rugged substrate. In a preferred embodiment, all glass substrates are utilized, with the transparency of the glass permitting accurate alignment of the styli or nibs. The use of glass substrates also increases the wear resistance of the completed printhead. A specialized bus matrix permits reduction in the width of the substrates carrying the styli, with the bus structure being formed on a single side of the substrate carrying the styli, such that thru-holes need not be provided through the thin substrates. A staggered, offset, oppositely facing contact pad structure is provided at the base of styli-bearing substrates to accommodate multiple rows of printing elements.

Large-scale printhead for non-impact printer and method of manufacture

An optical grating is provided by the deposition of thin layers of alternating materials on a substrate, the cross-section of which provides a three-dimensional grating. In one embodiment an alternating layered structure is provided by vacuum deposition of optically differing materials on a planar substrate, thereby to provide alternating layers defining planes parallel one to the other. The resulting structure is sectioned and polished such that the exposed adjacent ends of the alternating layers provide either a reflective or transmission grating of exceptional precision and accuracy due to the linear sharply-defined interfaces between adjacent exposed layers. In one embodiment, the finished structure is utilized as an optical coupler for coupling light into and out of an optical integrated circuit. In another embodiment, the grating is incorporated into a substrate over which an optical waveguide or an electro-optical element may be formed.

Optical grating and method of manufacture

A thick film patterned substrate is provided by laminating together a number of layers of dry photoresist without utilizing a baking step so as to provide an increased thickness resist without shrinkage, coefficient of expansion mismatch or damage to the photographic properties of the final structure. The increased thickness resist is adhered to a substrate, followed by selectively exposing the resist in a single step, developing the resist by directing a pressurized mist to the top surface of the resist and depositing material at the exposed portions of the substrate to the level established by the laminated layers. In the lamination process, the polyethylene release sheet normally used for a layer is peeled off and the layer is laminated to the substrate with the application of heat and pressure. This is followed by peeling off the polyester oxygen barrier sheet from the top of the dry resist. The next resist layer with its release sheet removed is laid on top of the first layer and laminated to the first layer by the application of heat and pressure, with the process being repeated for a number of layers until the desired thickness is achieved. The laminated dry resist and pressurized mist permits patterning of conductive films having a thick film conductivity, with resolution and line uniformity comparable to that obtainable with thin film techniques. For increased pattern definition the top polyester layer is peeled off, with an oil film being substituted to perform as an oxygen barrier and to permit intimate contact of the mask with the top surface of the laminated resist.

Method for providing high resolution, highly defined, thick film patterns

A method of forming a monolithic structure is disclosed in which insulated conductors are embedded in a block or body of conductive material. The conductors are built up on a conductive substrate selectively coated with a dielectric layer to form oversized pads over which the conductors are to be formed. The entire structure is then provided with an overlying conductive layer to allow patterned electrodeposition in which the conductors to be embedded are built up over the pads. After the formation of one level of conductors, the previously deposited conductive layer is selectively removed between the conductors so as to leave the conductors insulated from each other and situated on the oversized pads. The conductors are then overlaid with a dielectric material so as to encase each conductor in an insulative sheath. This is followed by a masking step in which the tops of the conductors are masked off. Thereafter the original conductive substrate is built up so as to surround the sides of the encased conductors and the process is repeated so as to provide an overlying second set of embedded conductors, likewise insulated from the conductive substrate in which they are embedded. The multi-layer embedded conductor structure may be utilized as a magnetic recording head, in the formation of inductors as multiwire cables, or may be utilized as a read/write head for digital computers. The subject device may also be fabricated in the form of a magnetic transducer, used for example in rotary or linear encoders.

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Tewksbury, MA, United States of America

Lowell E Thomas