Browse Prior Art Database

Field Use Front-of Screen Geometry Gauge

IP.com Disclosure Number: IPCOM000112433D
Original Publication Date: 1994-May-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 84K

Publishing Venue

IBM

Related People

McLachlan, GR: AUTHOR

Abstract

Disclosed is a gauge for front of CRT screen adjustments by plant or field engineers. It provides an economic, compact, durable tool to set height, width, vertical and horizontal centring of a range of displays by a single gauge.

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This is the abbreviated version, containing approximately 52% of the total text.

Field Use Front-of Screen Geometry Gauge

      Disclosed is a gauge for front of CRT screen adjustments by
plant or field engineers.  It provides an economic, compact, durable
tool to set height, width, vertical and horizontal centring of a
range of displays by a single gauge.

      The gauge is made fron clear polycarbonate sheet (1) of
suitable thickness (2) typically 2 mm.  The example shown in the
Figure is 100 mm wide by 120 mm high.  The top (3) and bottom (4)
ends are bent at opposite right angles to the main plane of the gauge
to form reference edges.  The width of the strips 3 and 4 are sized
to suit the bezel slot.  Three strips 20 mm wide of mirror tape X, Y
and Z are provided for three product types X, Y and Z of screen on
this single gauge.  All strips are laid parallel to each other on the
sheet (1) across ends 3 and 4.

      Two slits (5) are cut in each tape at a distance from the
appropriate reference edge 3 or 4 to achieve the specified
height/width (6) for that machine type image size measured from the
centre of the slit (7).  Specified tolerances in the measurement are
accommodated by selecting a width of the slits (5) to suit the
designated product type X, Y or Z.  The identifying product type
legend at the "height" end (4) of the gauge are shown mirror imaged
and inverted because they are viewed from the opposite side of the
gauge and with the gauge turned 90º  for the height adjustment.

      To achieve the best possible results with the gauge it is
necessary to position the eye correctly when looking at the gauge.
This is done by looking at the mirror tape and positioning the
reflection of the eye so that the reflection of the pupil is in the
slit in the mirror tape.  The distance from the eye to the gauge is
not critical but an approximate 300 mm viewing distance is
recommended.

When presetting the geometry the following procedure is observed:

1.  The appropriate geometry pattern should be displayed on the
    screen.

2.  Preset the geometry in the following manner:
     a.  Using the HEIGHT and VCENT pots obtain the maximum picture
         HEIGHT within the bezel aperture.
     b.  Reduce the HEIGHT by approximately 10 mm on each side.
     c.  Using the WIDTH and HCENT pots obtain the maximum picture
        WIDTH within the bezel aperture.
     d.  Reduce the WIDTH by approximately 10 mm on each side.

When adjusting the Height/Vcent the following procedure applies:

1.  Ensure the correct gauge...