HP L1940 Service Manual

73
HP L1940
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GENERALPRODUCT SPECIFICATION(Continued)
23
BRAND : HP L1940
19 inch LCD Monitor
TYPE :EJ6B50/02
8639 000 15804
2004-08-31
2004-08-31
590
28
Jacky Lee
patternsmaybe visible when viewed from off-axis.
10.7 Optical Light Leakage
There shall not be visible light from the back-lighting systemaround theedges of the screen as seen froma
distanceof20inchesfrom the screen withanoverhead light level of10lux. The manufacturer shall furnish
samples of the monitorwith each supported LCD module showing the maximumamount oflight leakage. This
sample shall be con
sidered the worst case light leakage sample and all panels used forproduction shall
have alesseramount oflight leakage.
10.9 LCD Inspection
Put LCD panel on inspection table and illuminate the panelwithadaylight fluorescent lamp located abovethe
panels
urface such thattheilluminance atthe LCD panel isbetween 1000 luxand 1500 lux. Defect limitsare
given in Table 3for the combined defectsfrom this inspection and theelectrical and mechanical de
fectsfrom
Table 4.
Table 4 DefectInspection
AverageDiameter
smaller of (L+W)/2 or L/20+2W
Acceptable
Number
Minimum
separation
<0.1mm Non countableN/a
0.1 mm 0.3 mm
10 15 mm
0.31 mm 0.5 mm
10 15 mm
0.51 mm 1.25 mm
515mm
1.26 mm 2.5 mm
3 25.4 mm
2.51 mm 3.75 mm
3 25.4 mm
Greater than 3.75 mm none Not applicable
Allowabledistance between spots of two sizes is the minimumseparation numberfor the smallerspot.
Therefore, if there aretwo spots, 1.30 mm and 0.4 mm in diameter, theymust be at least 15 mm apart
.
11.0 USB 2.0 HUB
TheUSBhub shall be powered by the internal supply of the monitor. The communication protocolshallcomply
with USBspecification revision 2.0. A singleupstream connector shall serve as connection to theCPUor other
USBhub. Each of the 2 downstream ports shall include current-limited power of5VDC at 500mA for use by an
attached device.
USB Signals
USBsignals shall meet thetimingand signal levelstandardsforhi
gh speed devicesset forthbyindustry
standardUSBspecification revision 2.0. Each downstream port shall provide 5VDC atup to 500mA for use by
an attached USB device.
Communication Protocol
USBconnections shall bees
tablished via4-conductor USB cables. USB cablesmust be shielded in
accordance with theUSBspecification forhigh speed devices.

HP L1940 Specifications

General

Brand	HP
Model	L1940
Category	Monitor
Language	English