7.5.1.2 Pupil Match

The optical and image quality specifications assume that the exit pupil of the illumination optics is nominally

centered within 2° of the entrance pupil of the projection optics. Misalignment of pupils can create objectionable

artifacts in the display border or active area. These artifacts may require additional system apertures to control,

especially if the numerical aperture of the system exceeds the pixel tilt angle.

7.5.1.3 Illumination Overfill

The active area of the device is surrounded by an aperture on the inside of the DMD window surface that masks

structures of the DMD device assembly from normal view. The window aperture is sized to anticipate several

optical operating conditions. Overfill light directly illuminating the window aperture can create adverse imaging

effects, and additional device heating leading to reduced device lifetime. Direct incident illumination should be

prevented from striking the DMD window aperture.

7.6 Micromirror Array Temperature Calculation

Window Edge

(4 surfaces)

TP3

TP2

TP2

TP3

TP1

TP1

Illumination

Direction

Off-state Light

Figure 7-1. Thermal Test Point Location - FQK Package

Micromirror array temperature cannot be measured directly, therefore it must be computed analytically from

measurement points on the outside of the package, the package thermal resistance, the electrical power, and

the illumination heat load. The relationship between array temperature and the reference ceramic temperature

shown as TP1 in Figure 7-1 is provided by the following equations:

(1)

(2)

where

DLP300S

DLPS214A – JULY 2021 – REVISED AUGUST 2021

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