DLP500YX: DLP500YX 8-bit gray pattern rate(prestored patterns with illumination modulation)

Hello Pan,

My apologies, I wrote the section in the EVM Guides that cover this and it is not clear enough.  I will have to clarify this when I next update the Guides.

Here is how it is done.  I will use the DLP500YX as the example.  You need to build the 8 1-bit images (bit-planes) of the 8 bit image you wish to display.  Then enter them as 8 1-bit images in the Pattern Design box with an "exposure" of 62 us.

Here is the part that I poorly explained.  In the Dual DLPC900 EVM Guide (DLPU102C) section 4.6.7 Pattern Settings it says, "The LED enable signals from the DLPC900 can be used to control the illumination modulation of the LEDs."

Actually it should say that you can control the enable directly (not from the C900) to create shorter illuminations times.  You can either use Trigger out 2 or the LED enable from the controller to start your LED illumination, but you must arrange to cut it short at the right illumination timing.  The system will not cut the time short on it's own.

Let me walk through the example for 8 bits.

1. LSB - cut the enable to the LED after (62us / 128) = 484 ns
2. LSB + 1 - cut the enable to the LED after (62us / 64) = 969 ns
3. LSB + 2 - cut the enable to the LED after (62us / 32) = 1.94 us
4. LSB + 3 - cut the enable to the LED after (62us / 16) = 3.88 us
5. LSB + 4 - cut the enable to the LED after (62us / 8) = 7.75 us
6. LSB + 5 - cut the enable to the LED after (62us / 4) = 15.5 us
7. LSB + 6 - cut the enable to the LED after (62us / 2) = 31 us
8. MSB - cut the enable to the LED after (62us / 1) = 62 us

Now the total 8-bit pattern time is 8*62us = 496 us.  Which gives an 8-bit pattern rate of (1 / 496us) = 2016 Hz,

Fizix

Hello Pan,

You wrote, "But this method can be fully implemented through DLPC900, rather than through external LED enabled control."

Did you mean this as a question?  Through the GUI it is not possible to directly cut the enable short.  

The ns LED minimum pulse width is only for use with 16-bit sequences and only with the DLP500YX DMD (DLPC900 data sheet [DLPS037H] Table 6-4).  The Programmers Guide [DLPU018J] section 2.3.7.4 Minimum LED Pulse Width in nanoseconds (ns) discuss this.

The DLPC900 data sheet indicates that it is possible to achieve 2016 8-bit operation, but does require special implementation by the user, and is not directly supported by the GUI.  Please note - There are many things that can be done that are not supported in the GUI.

Fizix

Hello again Pan,

I have sent you a friend invite so we can potentially set up a telephone conference.

Fizix