Browse Prior Art Database

Digitizer Over Head Projector Panel

IP.com Disclosure Number: IPCOM000113192D
Original Publication Date: 1994-Jul-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Suzuki, H: AUTHOR

Abstract

Disclosed is an overhead projector using LCD (Liquid Crystal Display) Panel. This LCD panel has a backlight which can be removed from LCD panel. When the backlight is removed, the LCD panel can function as transparent display device in which the presentation screen is generated by the PC. The PC and this LCD panel are connected through a cable. This LCD is placed on the conventional overhead projector which usually uses the transparent film. This LCD panel is used with a screen in which the sensor grids are embedded, and are able to detect the location of the OHP pointer.

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Digitizer Over Head Projector Panel

      Disclosed is an overhead projector using LCD (Liquid Crystal
Display) Panel.  This LCD panel has a backlight which can be removed
from LCD panel.  When the backlight is removed, the LCD panel can
function as transparent display device in which the presentation
screen is generated by the PC.  The PC and this LCD panel are
connected through a cable.  This LCD is placed on the conventional
overhead projector which usually uses the transparent film.  This LCD
panel is used with a screen in which the sensor grids are embedded,
and are able to detect the location of the OHP pointer.

      The Figure shows one of the implementation of this digitizer
Overhead Projector (OHP) panel.  This is composed of the transparent
LCD module, a screen, a pointer, a connection cable and the PC.

      The screen has sensor grids, and functions as the digitizer
with the pointer which has photo-detector.  By removing the backlight
and a back cover from the LCD module, the LCD module becomes
transparent, then the light can pass through the LCD module to the
screen.

      A button image is displayed on the screen, and the PC knows the
location of this button.  The pointer is generating the magnetic
field.  Then the sensor grids detect the magnetic field which is
generated by the pointer when the operator make the pointer close to
the button on the screen.  The information of the button location is
sent to the PC.  Then the PC can...