TI assumes no responsibility for end-equipment optical performance. Achieving
the desired end-equipment optical performance involves making trade-offs between
numerous component and system design parameters. See the related application
reports in Section 12.2.1 for guidelines.
PARAMETER |
TEST CONDITIONS |
MIN |
NOM |
MAX |
UNIT |
α |
Micromirror tilt angle |
DMD parked state (1)
(3)
(4), see (10) |
|
0 |
|
degrees |
DMD landed state
(1)
(5)
(6), see (10) |
11 |
12 |
13 |
β |
Micromirror
tilt angle variation (1)
(5)
(7)
(8)
(9) |
See (10) |
–1 |
|
1 |
degrees |
|
Micromirror
crossover time (2)
(11) |
|
|
5 |
|
μs |
|
Micromirror
switching time (11) |
|
|
16 |
|
μs |
|
Orientation of
the micromirror axis-of-rotation (12) |
|
89 |
90 |
91 |
degrees |
|
Micromirror
array fill factor (13)
(14)
(17) |
f/3
illumination at 24 degree angle, mirrors tilted toward
illumination |
|
92% |
|
|
|
Mirror metal
specular reflectivity (13)
(14) |
700 nm to 2500
nm |
|
89% |
|
|
|
Window material |
|
Corning
Eagle XG |
|
|
Window
aperture |
|
|
See (15) |
|
|
|
Illumination
overfill (16) |
|
|
See (16) |
|
|
|
Window transmittance (single pass through
two window surfaces) (13)
(14) |
2000 nm to 2500 nm, See Figure 7-5 |
|
90% |
|
|
Image performance(18) |
Bright
pixel(s) in active area (19) |
Gray 10 Screen
(20) |
|
|
0 |
micromirrors |
Bright
pixel(s) in the POM (21) |
Gray 10 Screen
(20) |
|
|
1 |
Dark pixel(s)
in the active area (22) |
White
Screen |
|
|
4 |
Adjacent
pixel(s) (23) |
Any
Screen |
|
|
0 |
Unstable
pixel(s) in active area (24) |
Any
Screen |
|
|
0 |
(1) Measured relative to the plane formed by the overall
micromirror array.
(2) Micromirror crossover time is primarily a function of the
natural response time of the micromirrors.
(3) Parking the micromirror array returns all of the
micromirrors to a relatively flat (0°) state (as measured relative to the plane
formed by the overall micromirror array).
(4) When the micromirror array is parked, the tilt angle of
each individual micromirror is uncontrolled.
(5) Additional variation exists between the micromirror array and
the package datums.
(6) When the micromirror array is landed, the tilt angle 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 an nominal angular position of +12°.
A binary value of 0 results in a micromirror landing in an nominal
angular position of –12°.
(7) Represents the landed tilt angle variation relative to
the nominal landed tilt angle
(8) Represents the variation that can occur between any two
individual micromirrors, located on the same device or located on different
devices.
(9) 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 or system
contrast variations.
(11) Performance as measured at the start of life.
(12) Measured relative to the package datums B and C, shown in the
Package Mechanical Data section in
Section 13.
(13) The nominal DMD total optical efficiency results from the
following four components:
- Micromirror array fill
factor
- Micromirror array
diffraction efficiency
- Micromirror surface
reflectivity (very similar to the reflectivity of bulk Aluminum)
- Window Transmission
(single pass through two surfaces for incoming light, and single pass
through two surfaces for reflected light)
(14) The DMD diffraction efficiency and total optical efficiency
observed in a specific application depends on numerous application-specific
design variables, such as:
- Illumination wavelength,
bandwidth or line-width, degree of coherence
- Illumination angle, plus
angle tolerence
- Illumination and
projection aperture size, and location in the system optical path
- Illumination overfill of
the DMD micromirror array
- Aberrations present in
the illumination source or path, or both
- Aberrations present in
the projection path
Does not account for the effect of micromirror
switching duty cycle, which is application dependent. Micromirror switching duty
cycle represents the percentage of time that the micromirror is actually
reflecting light from the optical illumination path to the optical projection
path. This duty cycle depends on the illumination aperture size, the projection
aperture size, and the micromirror array update rate.
(15) See the Package Mechanical Characteristics in
Section 13 for details regarding the size and location of the window
aperture.
(16) The active area of the DLP4500NIR 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 aperture is sized to anticipate
several optical conditions. Overfill light illuminating the area outside the
active array can scatter and create adverse effects to the performance of an end
application using the DMD. Design the illumination optical system as to limit
light flux incident outside the active array to less than 10% of the light flux
level in the active area. Depending on the particular system's optical
architecture and assembly tolerances, the amount of overfill light on the
outside of the active array may cause system performance degradation .
(17) The Micromirror array fill factor depends on numerous
application-specific design variables, such as:
- Illumination angle, plus
angle tolerance
- Illumination and
projection aperture size, and location in the system optical path
(18) 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
(19) Bright pixel definition: A single pixel or mirror that is stuck in the ON
position and is visibly brighter than the surrounding pixels
(20) Gray 10 screen definition: All areas of the screen are colored with the
following settings:
Red = 10/255
Green = 10/255
Blue = 10/255
(21) POM definition: Rectangular border of off-state mirrors surrounding the active
area
(22) Dark pixel definition: A single pixel or mirror that is stuck in the OFF
position and is visibly darker than the surrounding pixels
(23) Adjacent pixel definition: Two or more stuck pixels sharing a common border or
common point, also referred to as a cluster
(24) 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