Planar LC640.480.33-AC manual Temperature Considerations, Thermal Shutdown

Page 24

Temperature Considerations

Thermal Shutdown

A thermal sensor referenced to the center of the backlight/inverter ECA prevents the inverter from starting at an ambient temperature of –30 °C or below, and will shut off the backlight at an ambient temperature of approximately +90 °C and above.

Luminance Variation Due to Ambient Temperature

Although the inverter features regulated lamp current drive, luminance will vary across the temperature range due to the characteristics of the CCFL tubes. Lamp luminance decreases at low temperatures as the mercury condenses out of the gas and it decreases again at high temperatures as the tube phosphors become less efficient. The LC640.480.33-AC has been designed to provide peak luminance at normal room temperatures.

Backlight power consumption decreases as temperatures climb as the working voltage of the CCFL tubes decreases. The graph in Figure 13 indicates typical performance across temperature.

Figure 13. Luminance vs. Temperature.

 

 

 

 

Luminance vs. Temperature

 

 

 

100

 

 

 

 

 

 

 

 

 

30.0

 

 

90

 

 

 

 

 

 

 

 

 

25.0

W

 

80

 

 

 

 

 

 

 

 

 

Luminance,%

 

 

 

 

 

 

 

 

 

5.0

BacklightPower,

20

 

 

 

 

 

 

 

 

 

 

70

 

 

 

 

 

 

 

 

 

20.0

 

 

60

 

 

 

 

 

 

 

 

 

 

 

 

50

 

 

 

 

 

 

 

 

 

15.0

 

 

40

 

 

 

 

 

 

 

 

 

10.0

 

 

30

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

 

 

 

 

0.0

 

 

-20

-10

0

10

20

30

40

50

60

70

80

Lum, %

ta, C

 

 

 

PH, W

 

 

 

22 LC640.480.33-AC Operations Manual (OM600-01)

Image 24
Contents LC640.480.33-AC Date Description Contents Figures Features and Benefits LC640.480.33-AC DisplayInstallation and Handling Mounting the DisplayMounting Display Face Down Mounting ECA Face DownCleaning Cable LengthAvoiding Image Retention Specifications Environmental CharacteristicsMechanical Characteristics Environmental CharacteristicsOptical Characteristics Safety and EMIOptical Characteristics Reliability and Backlight LifePower Requirements Power Sequencing LCD onlyInterfacing and Operation Control BasicsBacklight Signals Backlight Signal DC CharacteristicsVideo Signals Video Signal CharacteristicsVideo Signal DC Characteristics Video ModesSignal Timing Video signal timingVertical mode video signal timing Timing Diagram, 480-line mode Timing Diagram, 400-line mode Timing Diagram, 350-line mode Video Characteristics Video Data Color/Grayscale MapConnectors Pixel PositionVideo Connector J3 Video Connector J3 PinoutsDimming Connector J2 Backlight Power Connector J1Dimming Connector J2 Pinouts Backlight Power Connector J1 PinoutsOptical Features Viewing AngleResponse Times DimmingBacklight Dimming Modes Dimming Control InterfacingBacklight Dimming Modes Inverting the Display Inverting the DisplayTemperature Considerations Luminance Variation Due to Ambient TemperatureThermal Shutdown Display Dimensions Warm-up CharacteristicDisplay Dimensions Description of Warranty Support and ServiceOrdering Information OM600-01