various test benches for a projector

1. MEASURING & TESTING
BEAMER / PROJECTOR.
Manish Abraham & Reinhard Pollhamer

2. Table of Contents
 Product Description.
 Technical Aspects.
 LCD Memory Effect.
 Humidity and Temperature.
 Cooling Fan Defect.
 Lamp Durability.

3. Product Description
 Video projector
 Receives a video signal from TV-receiver, PC, BluRay-
Player, gaming console etc.
 Projects the pictures on a projection screen.
 Uses a lens system.

4. Product Description
 Lens system of a LCD-Projector.

5. Technical Aspects
 Light output
 measured in lumens.
 from 1500 lm for small rooms with low ambient light up
to over 4000 lm for big screens and/or no lighting
control.
 Resolution
 common resolutions are 800x600, 1024x768,
1280x720 and 1920x1080 pixels.
 other formats have to be scaled.

6. Technical Aspects
 Picture deformation
 when projector has a horizontal or vertical offset to the
projection screen.
 digital or analog correction.
 Temperature and noise
 heat is produced by the lamp.
 fans are needed to protect from
overheating.

7. What could be tested?
 LCD Memory Effect.
 Button durability.
 Remote control (distance, obstacles).
 Lamp durability (3000-6000h; On/Off).
 Humidity and temperature differences.
 Defect of cooling fan.
 Light output (decreasing over lifespan).

8. What is to be tested?
 LCD Memory Effect: places on the lense can get
darker if they are exposed to bright pictures.
 Lamp durability: lamp is designed for 5000
operating hours.
 Humidity and Temperature: the projector should be
resistant to inside as well as outside conditions.
 Defect of cooling fan: overheating of critical
components should be prevented.

9. LCD Memory Effect Test
 To give an idea of different test parameters, I
would like to show a presentation on different
parameters and then show our test.

10. LCD Memory Effect
 2 test pictures
 Testing durations: 15 / 30 / 45 / 60 / 70 / 80 /
90 / 100 / 120 / 150 / 180 minutes

11. LCD Memory Effect
 Results
 Check image quality of a pure black respectively pure
white image after each time period.
 Protocol at which time and place/color
the effect occured.

12. LAMP DURABILITY
 The Lamp inside a Projector.

13. Lamp Durability
 Lamp should endure 5000 hours of usage
(>200 days).
 Long time usage and many Power-On/Off
procedures have a bad influence on durability.
 To shorten the test time the projector is switched
On/Off frequently.
 Randomized On/Off-signals or fixed values.

14. Humidity and Temperature
 Intended temperature range for use
 between -5° C and +40° C
 Intended humidity range for use
 between 20 and 90 %
 Protocol sheet with intervals
 shorter intervals at critical temp. or humidity levels
 Test environment
 climate chamber

15. Humidity and Temperature
Humidity [%] Temperature [°C] Status
20 20 OK
40 20 OK
60 20 OK
70 20 OK
75 20 …
80 20 …
85 20 …
90 20 …
92 20 …
94 20 …

16. Cooling Fan Defect
 System must shut down before overheating
 Temperature sensors in the projector case

17. Cooling Fan Defect
 1st task: find the critical temperature.
 2nd task: configure the built-in temperature sensor.
 3rd task: test if the system shuts down when the
critical temperature is reached.

18. Questions ?????