Summagraphics Corporation

Alexander M Purcell

David A Siefer

Thomas C Zalenski

A digitizer system comprises a source of a light for producing an image, a shutter, and a transparent or translucent digitizer tablet. The source is positioned to direct the image to the tablet via the shutter. The shutter comprises a liquid crystal layer and transparent planar conductors on opposite surfaces of the layer. The system further comprises a source of an adjustable voltage connected between the planar conductors for adjusting the transmissivity of the shutters.

Liquid crystal shutter for backlit digitizer

A digitizer tablet is provided in which the working surface is illuminated by a light source which includes optical structure located over the grid or electrode array of the position determining structure of the digitizer to provide a surface-lit tablet, or beneath the grid or electrode array to provide a back-lit tablet. Preferably, a space is provided adjacent the working surface to reduce undesirable lighting effects. A fiber optics panel or an electroluminescent panel may be used as the optical structure placed above or beneath the grid to illuminate the working surface. The position determining structure and the optical structure may be integrated into a single unit to form a digitizer with an illuminated working surface, or the optical structure may be provided as a separate unit for use with a digitizer to provide an illuminated working surface for the digitizer.

Digitizer tablet with illuminable working surface

Stylus for digitizer tablet, with the stylus provided with a finger-actuated side control for controlling the magnitude of a Z-axis signal. The side control remains in the position placed by the user, and preferably comprises a slide switch mounted on the side of the stylus housing.

Digitizer stylus with z-axis side control

A method and apparatus for indicating the position of a cursor on a surface in first and second different directions. The cursor is mounted on a member such as a gantry, and the gantry is guided for movement in the first direction on a carriage. The carriage is mounted for movement in the second direction on a member such as a rail. Radiation reflection strips extending and an acute angle with respect to one another are mounted on the gantry, and adapted to reflect light from a linear light source on said rail and extending in the second direction. Reflected light is sensed by a linear detector on said rail, for producing signals corresponding to the locations from which light was reflected. The coordinates of the cursor are determined by triangulation from these signals.

Method and apparatus for producing signals corresponding to the position

A digitizer stylus with Z-axis side pressure control, comprising a nib front end resiliently mounted on the stylus housing and cooperating with a Hall-effect transducer such that side pressure on the nib, used like a calligraphic pen or brush, modifies the Hall-effect output, which can be used to modify an additional parameter, such as line width, of a drawing.

Digitizer stylus with Z-axis side pressure control

Digitizer tablet and digitizer tablet structure having an illuminable working surface are disclosed. A space between a top translucent layer having the working surface and a source of light is provided so as to eliminate or minimize undesirable lighting effects at the working surface. In the preferred embodiments, the space is an air gap (e.g. 0.060-0.250 inch) immediately adjacent the top translucent layer. The air gap is formed by transparent optical fibers or solid glass or acrylic rods. Back-lighted, translucent, back-lightable (without light source) and surface lighted digitizer tablet embodiments are described.

Digitizer with illuminable working surface

A stylus having a pressure sensitive side switch for use with digitizer apparatus is disclosed. The pressure sensitive side switch is activated by the application of pressure thereto substantially normal to the axis of the stylus by the finger of a user. In the illustrated embodiments, the pressure sensitive switch comprises a movable element, and the switch provides a signal related to movement of the movable element substantially normal to the stylus axis. The switch output in the preferred embodiment is linearly related to movement of the movable element. The switch may comprise a magnet and a Hall-effect device mounted in the stylus for movement relative to each other. The pressure sensitive side switch may be used to control line width, coloring, gray scaling, Z-axis input, etc.

Digitizer stylus having side switch

An optical device comprising a sheet of optical fibers having different lengths so that the fiber ends are distributed uniformly over a given area. The device is mounted in a digitizer tablet above or below its electrode array. When light is pumped into the free fiber ends, a pattern of light spots are formed which can be spread out to illuminate the tablet's working surface. When driven by a light pen, a similar optical device can be used to locate the light pen for menu-picking functions.

Distributed optical fiber device for digitizer tablet

A coordinate determining system, tablet, and method wherein the tablet is formed of a sequence of triangular electrodes extending in a first direction, with alternate electrodes having their apexes extending in opposite directions perpendicular to the first direction, and the bases of alternate electrodes are aligned to define the sides of the tablet. The cursor is round, having a diameter substantially equal to the length of the bases of the electrodes, and is adapted to be electrostatically coupled to the electrodes. Signals are sequentially applied to the electrodes and voltages generated at the cursor are employed to address look up tables for determining the location of the cursor.

Position determining and digitizing method and device

A coordinate position determining system and method includes a liquid crystal material separating first and second groups of conductors. The tablet is at least partially light transmissive, but may include a partially reflective layer. The first and second groups or conductors are sequentially scanned at different times. A wand adapted to be positioned against the tablet includes a light detector, and may also include a light source.

Liquid crystal position determining system and wand device

A low-power electromagnetic digitizer table employing triangular-shaped electrodes arrayed in a single plane. A pointing device coil when energized induces signal voltages in the electrodes underneath. The electrodes are scanned in timed relation, and the induced voltages digitized and compared to determine the X/Y coordinates of the pointing device with respect to the electrode array.

Low-power electromagnetic digitizer tablet

A backlit digitizer tablet providing uniform illumination of the working surface, comprising biaxial fluorescent lamps supplying wide-area light emission under a sandwich top construction including an apertured shield electrode, a first clear spacer, an electrode array, a second clear spacer, and a translucent top, with optically transparent support means for the top.

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Guilford, CT, United States of America

Alexander M Purcell