參數(shù)資料
型號(hào)： LM9831
廠商： National Semiconductor Corporation
英文描述： LM9831 42-Bit Color, 1200dpi USB Image Scanner
中文描述： LM9831 42位彩色，1200dpi的USB圖像掃描儀
文件頁(yè)數(shù)： 25/41頁(yè)
文件大小： 320K
代理商： LM9831
25
www.national.com
When the Resume Scan signal is received, the stepper motor
controller waits the appropriate number of pixel periods after the
next TR pulse and then starts stepping again at the normal rate.
The first new line transmitted is determined by the
Lines to Dis-
card After Resume Scan Signal
register. The discard value
must be the same as the value in the
Lines to Process After
Pause Scan Signal
register.
a
4.4 Pause Behavior - Reversing Mode
If the
Full Steps to Reverse When Buffer is Full
register is >0,
then the Reversing Mode is enabled.
The Reversing Mode eliminates spatial distortion due to the
pausing of a scan. When the Pause Scan signal is received, the
line currently being processed is completed and stored in RAM
(line “b” in Figure 17). When the scan resumes, ideally the
LM9831 would send out lines “c” and after under the exact same
speed and positional conditions the scanner was in before the
scan paused (as indicated by the dotted line in Figure 17).
When the Pause Scan signal is received, the LM9831 processes
the remainder of the line currently being read from the CCD (line
b), and stores the offset (in pixel periods) between the last TR
pulse and the last step. It then stops, reverses, stops, and waits
for the Resume Scan signal. Once Resume Scan is asserted, the
motor controller waits for the previously stored number of pixels
periods, then starts moving forward again, maintaining the same
phase relationship between the TR pulse and the stepper motor
control signals. The result is as if the stepper motor had never
paused.
Stopping, reversing, and resuming forward motion all follow the
curve programmed in the
Acceleration Profile
configuration reg-
ister. There are 3 segments (Stopped, 25%, and 50%), and the
number in each register indicates the number of full steps to stay
at that acceleration. A value of 0 indicates that that segment is to
be skipped. For example, a value of 0 in all three registers would
mean that the motor would instantly reverse when the buffer is
full, then instantly stop after going back the specified number of
lines.
This acceleration profile is used any time the motor is started,
stopped, or reversed.
The acceleration profile for stopping, reversing, stopping, and
going forward again is this:
Full speed forward (1 microstep = #pixels in
Scanning Step
Size
register) until the Pause Scanning signal is received.
50% speed forward for z full steps (1 microstep = 2* #pixels in
Scanning Step Size
register)
25% speed forward for y full steps (1 microstep = 4*#pixels in
Scanning Step Size
register)
Stopped for x full steps (1 microstep = #pixels in
Scanning
Step Size
register).
25% speed backward for y full steps (1 microstep = 4*#pixels in
Scanning Step Size
register)
50% speed backward for z full steps (1 microstep = 2* #pixels in
Scanning Step Size
register)
Full speed backward (1 microstep = #pixels in
Scanning Step
Size
register) for number of microsteps in the
Steps to
Reverse
register
50% speed backward for z full steps (1 microstep = 2* #pixels in
Scanning Step Size
register)
25% speed backward for y full steps (1 microstep = 4*#pixels in
Value
Additional Lines to Store in DRAM
0
1
2
...
7
0(a only)
1 (a and b)
2 (a, b and c)
...
7
Figure 14: Lines to Process after Pause Scan Signal
Register
Value
First Line to Transmit After Pause
0
1
2
...
7
b
c
d
...
i
Figure 15: Lines to Discard After Resume Scan Signal
Register
Figure 16:
Stepper Motor Resuming
TR
Microstep
Pulse
Resume
Scanning
Signal
b
c
d
Speed
Register
DAC output
Stopped
(x = 0 to 3)
x = number of full step clocks to wait
before reversing motor.
y = number of full steps at 25% of final
speed. Full step period = 4 full step
clocks.
z = number of full steps at 50% of final
speed. Full step period = 2 full step
clocks.
25%
(y = 0 to 3)
50%
(z = 0 to 3)
Figure 18: Acceleration Profile Settings
Figure 17:
Reversing - The Goal
TR
Microstep
Pulse
Pause
Scanning
Signal
a
b
c
d
Microstep Pulse
(if motor had not
paused)
e
相關(guān)PDF資料
PDF描述
LM9831CCVJDX LM9831 42-Bit Color, 1200dpi USB Image Scanner
LM9832CCVJD LM9832 42-Bit Color, 1200dpi USB Image Scanner
LM9832 LM9832 42-Bit Color, 1200dpi USB Image Scanner
LM9833CCVJD LM9833 48-Bit Color, 1200dpi USB Image Scanner
LM9833 LM9833 48-Bit Color, 1200dpi USB Image Scanner
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM9831CCVJD 制造商:NSC 制造商全稱:National Semiconductor 功能描述:LM9831 42-Bit Color, 1200dpi USB Image Scanner
LM9831CCVJDX 制造商:NSC 制造商全稱:National Semiconductor 功能描述:LM9831 42-Bit Color, 1200dpi USB Image Scanner
LM9832 制造商:NSC 制造商全稱:National Semiconductor 功能描述:LM9832 42-Bit Color, 1200dpi USB Image Scanner
LM9832B-B WAF 制造商:Texas Instruments 功能描述:
LM9832B-E WAF 制造商:Texas Instruments 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*