6.11 Micromirror Array Optical Characteristics

PARAMETER

TEST CONDITIONS

MIN

NOM

MAX

UNIT

Micromirror tilt angle

DMD landed state(1)

17

degree

Micromirror tilt angle tolerance(2) (3) (4) (5)

–1.4

1.4

degree

Micromirror tilt direction (6) (7)

Landed ON state

180

degree

Landed OFF state

270

Micromirror crossover time(8)

Typical performance

1

3

µs

Micromirror switching time(9)

Typical performance

10

Image

performance(10)

Bright pixel(s) in active area

(11)

Gray 10 Screen (12)

0

micromirrors

Bright pixel(s) in the POM (13) Gray 10 Screen (12)

1

Dark pixel(s) in the active

area (14)

White Screen

4

Adjacent pixel(s) (15)

Any Screen

0

Unstable pixel(s) in active

area (16)

Any Screen

0

(1)

Measured relative to the plane formed by the overall micromirror array.

(2)

Additional variation exists between the micromirror array and the package datums.

(3)

Represents the landed tilt angle variation relative to the nominal landed tilt angle.

(4)

Represents the variation that can occur between any two individual micromirrors, located on the same device or located on different

devices.

(5)

For some applications, it is critical to account for the micromirror tilt angle variation in the overall system optical design. With some

system optical designs, the micromirror tilt angle variation within a device may result in perceivable non-uniformities in the light field

reflected from the micromirror array. With some system optical designs, the micromirror tilt angle variation between devices may result

in colorimetry variations, system efficiency variations, or system contrast variations.

(6)

When the micromirror array is landed (not parked), the tilt direction of each individual micromirror is dictated by the binary contents of

the CMOS memory cell associated with each individual micromirror. A binary value of 1 results in a micromirror landing in the ON state

direction. A binary value of 0 results in a micromirror landing in the OFF state direction. See Figure 6-18.

(7)

Micromirror tilt direction is measured as in a typical polar coordinate system: Measuring counter-clockwise from a 0° reference which is

aligned with the +X Cartesian axis.

(8)

The time required for a micromirror to nominally transition from one landed state to the opposite landed state.

(9)

The minimum time between successive transitions of a micromirror.

(10) Conditions of Acceptance: All DMD image quality returns will be evaluated using the following projected image test conditions:

Test set degamma shall be linear

Test set brightness and contrast shall be set to nominal

The diagonal size of the projected image shall be a minimum of 20 inches

The projections screen shall be 1X gain

The projected image shall be inspected from a 38 inch minimum viewing distance

The image shall be in focus during all image quality tests

(11) Bright pixel definition: A single pixel or mirror that is stuck in the ON position and is visibly brighter than the surrounding pixels

(12) Gray 10 screen definition: All areas of the screen are colored with the following settings:

Red = 10/255

Green = 10/255

Blue = 10/255

(13) POM definition: Rectangular border of off-state mirrors surrounding the active area

(14) Dark pixel definition: A single pixel or mirror that is stuck in the OFF position and is visibly darker than the surrounding pixels

(15) Adjacent pixel definition: Two or more stuck pixels sharing a common border or common point, also referred to as a cluster

(16) Unstable pixel definition: A single pixel or mirror that does not operate in sequence with parameters loaded into memory. The unstable

pixel appears to be flickering asynchronously with the image

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DLP4710LC

DLPS178C – MAY 2020 – REVISED JULY 2023

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