The VHR-200 Voltage Holding Ratio Measurement System
is a research and development tool designed to provide an affordable means
for determining the VHR of liquid crystal test cells.
Voltage Holding Ratio (VHR) is a critical electrical
parameter for liquid crystal displays (LCDs). VHR is a measure of the LCD
ability to retain a voltage during the time between pixel updates (frame
time). The VHR-200 has software adjustable drive pulse width and frame
time.
LCD manufacturers evaluate and test many new
alignment polymers and liquid crystals for LCDs. The type of alignment
polymer and liquid crystal can have a dramatic effect on the VHR of the
liquid crystal display and, therefore, manufacturers monitor VHR as part
of their evaluation. It was for this purpose that the VHR-200 was designed
and engineered.
The VHR-200 Voltage Holding Ratio Measurement System
includes such features as a laptop PC, CU-100 unit for independent testing
of the system, and VHRS acquisition software for the Windows operating
system.
Elsicon is currently marketing the VHR-200 Voltage
Holding Ratio Measurement System. If you are interested in discussing your
VHR measurement needs please contact the representative listed below.
VHR-200
Specifications
DUT* Charging and Measurement Parameters
User selectable parameters via software
Output Scan Voltage: ±1, 2, 4, 5, or 10Volts (± 5mV)
Charging Time: 64 or 512µs (±5%)
Output Frame Time: 0, 20, 50, 100, or 1000ms (±0.5%)
Number of measurement cycles: 1, 2, 5, or 10 cycles
Pre-condition cycles prior to measurement: 0, 1, 2, 5 or 10 cycles
Fixed parameters
Samples per frame: 100
System Properties
Input capacitance: <50 pf
Input leakage current: 100 pA maximum
Source impedance: ~130 ohms
D/A card included for data acquisition and control of VHR-200
Dimensions (w/o computer): Height: 33mm, Length: 105mm, Width:
126mm
Weight: 0.5Kg
VHRS Acquisition Software
Platform: Microsoft Windows
operating system
VHR value: 0-0.999 (0-99.9%)
Features:
VHR calculation method based on RMS value
Oscilloscope like display of measurement cycles including cursor readout
of the DUT voltage
Error indicators for unsymmetrical charging and offset in DUT voltage
Save DUT information and data to CSV file for further analysis using third
party software
System Requirements
Voltage Requirements:
VHR 200 is powered from the PC
100-120VAC, 50-60Hz, single phase for the PC
*DUT – Device Under Test
Specifications subject to change without
notice.
Contacts:
Wayne M.Gibbons
Elsicon, Inc.
Tel:(302)266-7030 ext.11
Fax:(302)266-7031
Email:wmgibbons@elsicon.com
Last updated 9/28/06