Non-Failure Information - Pioneer KRP-500P Service Manual

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5.5 NON-FAILURE INFORMATION

A
[1] FUNCTION OF DECREASING THE BRIGHTNESS LEVEL
If the panel temperature becomes high or a video signal that requires activation of panel protection is input, the unit will
protect the panel by decreasing the brightness level.
* While a mask is being displayed, the panel protection function will not be activated.
Protection Function
Name
High-temperature For protection of
protection function 1 parts (DCF)
High-temperature For reducing
protection function 2 heating in the unit
B
Panel protection For preventing
function 1 burn-in
Panel protection For protection of
function 2 SCAN ICs
Panel protection For protection
function 3 against panel
cracking
Limiting for the maximum number of SUS pulses
By gradually decreasing the limit for the maximum number of SUS pulses, the temperature of the panel will be lowered.
• The limit for the maximum number of SUS pulses will be decreased by 8 per 5 seconds.
• The lower limit for the maximum number of SUS pulses is about 700.
C
• The maximum number of SUS pulses will begin to increase gradually if the conditions that led to activation of the
protection function return to normal.
ABL adjustment value offset
By gradually offsetting the ABL adjustment value, the temperature of the
panel will be lowered. The number of SUS pulses, which is determined
based on the input APL (average picture level), will be decreased.
• The ABL adjustment value will be offset by one step per 30 seconds.
• The ABL adjustment value will be gradually restored if conditions that
let to activation of the protection function return to normal.
D
2000
E
700
F
Fig. 1: Relationship between input APL and number of SUS pulses
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1
2
Purpose Conditions
Panel temperature (TEMP1)
reaches 65 ºC.
Panel temperature (TEMP1)
reaches 80 ºC.
A still image is displayed for
3 minutes or more.
An image with which a particular
load is applied to one SCAN IC
is displayed. (See Fig. 2)
An image with which the heat of
part in the panel is increased is
displayed. (See Fig. 3)
Limiting for the maximum number
of SUS pulses
Offsetting of the ABL adjustment value
The number of SUS pulses with regard
to the input APL will be decreased.
2
3
Protection Function
Offsetting the ABL
adjustment value
Limiting for the maximum
number of SUS pulses
Limiting for the maximum
number of SUS pulses
Limiting for the maximum
number of SUS pulses
Limiting for the maximum
number of SUS pulses
Fig. 2: Detection example: SCAN IC protection
Fig. 3: Detection example: Protection against panel cracking
Input APL
KRP-500P
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Remarks
The picture will be considered to be still
if only the mouse cursor is moved.
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