HDSP-2301 HP [Agilent(Hewlett-Packard)], HDSP-2301 Datasheet - Page 43

• Manufacturer Part Number: HDSP-2301
• Description: Four Character 5.0 mm (0.20 inch) 5 x 7 Alphanumeric Displays
• Manufacturer: HP [Agilent(Hewlett-Packard)]

Figure 31. Wide Range Intensity Modulation Control and Power Switching of Display I
The Intensity and Color
Matching
The luminous intensity and domi-
nant wavelength of LED displays
can vary over a wide range. If
there is too great a difference be-
tween the luminous intensity or
dominant wavelength of adjacent
characters in the display string,
the display will appear objection-
able to the viewer. To solve the
problem, all HDSP-2000 displays
are categorized for luminous in-
tensity. The category of each
display package is indicated by a
letter preceding the date code on
7
8
1
1 K
6
TO CLOCK
ENABLE CIRCUITRY
ICM 7555 TRIGGER INPUT
ICM 7555 OUTPUT
1 K
TO COLUMN
COUNTER
2
3
LOAD
1.5 K
9
t
11
V CC
DISPLAY
10
100 pF
2N3906
CA3084
ICM7555
LOAD
the package. When assembling
display strings, all packages in the
string should have the same inten-
sity category. This will insure
satisfactory intensity matching of
the characters. All HDSP-2000
family displays are categorized in
overlapping intensity categories.
All characters of all packages des-
ignated to be within a given letter
category will fall within an inten-
sity ratio of less than 2:1. For dot
matrix displays, a character-to-
character intensity ratio of 2:1 is
not generally discernible to the
human eye.
6
2
7
t
TH
TR
DIS
DISPLAY
R
GND
4
OUT
V C
1
V +
8
3
8 V
V +
74LS04
1 K
74LS00
0.01 F
IN
LM350
ADJ
2N2219A
12
13
14
15
OUT
D
C
B
A
74145
0
1
2
3
4
120
360
Since the human eye is very sensi-
tive to variations in dominant
wavelength in the yellow and
green region, all yellow and green
HDSP-2000 family displays are
also categorized for dominant
wavelength. The dominant wave-
length bin for each display
package is indicated by a number
code following the category letter
code on the back of the package.
The dominant wavelength bins
are 3.5 nm wide for yellow and 4.0
nm wide for green. These domi-
nant wavelength variations are
generally not discernible by the
human eye.
35
3
4
5
1
2
CC
74LS04
V CC 1 TO DISPLAY V CC ONLY
0.01 F
to Conserve Power
5 V, 3 A
V CC
COLUMN 1
COLUMN 2
COLUMN 3
COLUMN 4
COLUMN 5
V B
AN1016.31