PD4
PERIPHERAL DEVICES
Bogdan Bartosiński
Department of Metrology and Optoelectronics
PERIPHERAL DEVICES
3. Input devices
Bogdan Bartosiński
Department of Metrology and Optoelectronics
User interface devices
PANELS AND TOUCH SCREENS
Touchpad
• a pointing device with
specialized surface that can
translate the motion and
position of a user's fingers to a
relative position on screen
• a common feature of laptop
computers, and are also used
as a substitute for a mouse
• the most commonly used is
capacitive technology
User interface devices
PANELS AND TOUCH SCREENS
TrackPoint
• TrackPoint (IBM), TrackStick
(Dell), Pointstick (HP, Compaq),
• can be used in ultra-compact
netbooks (Sony Vaio) where no
place for a touchpad
• operates by sensing applied
force (isometric joystick), using
a pair of resistive strain gauges
• the velocity of the pointer
depends on the applied force
• the touchpad operates 15%
faster than the trackpoint
User interface devices
JOYSTICK
User interface devices
JOYSTICK (joy – zabawa, stick –drążek)
– manipulator mounted on a fixed basis, moved in two
directions, that contains one or more additional buttons
– joystick classification: digital and analog
• digital - gives only on/off signals for four different
directions
• analog - a joystick which has continuous states, i.e.
returns an angle measure of the movement in any
direction in the plane or the space
– joystick classification: controlled by movement or pressure
• movement (absolute joystick) - position of joystick
coresponds to position of cursor
• pressure (isometric or velocity controlled joystic) pressure on stick corresponds to velocity of cursor
User interface devices
JOYSTICK
– application
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computer games
wheelchairs
cranes
excavators
in nearly all modern hydraulic control systems
Unmanned Aerial Vehicles (UAVs)
Remotely Operated Vehicles (ROMs)
– control vehicle
– control on board cameras
– control manipulators
• planes with system Fly-By-Wire
User interface devices
JOYSTICK
– the first electrical 2-axis joystick was probably invented
around 1944 in Germany for military application
– in the 1960s the use of joysticks became widespread
in radio-controlled model aircraft
– in 1963 of joystick was used to control of powered
wheelchairs
– the first video game joysticks was created in 1967
– from the 1980s the joystick used to control the flight
(Airbus), replacing the traditional yoke
User interface devices
JOYSTICK
digital joystick
User interface devices
JOYSTICK
digital joystick
User interface devices
JOYSTICK
digital joystick
User interface devices
JOYSTICK
Schematic diagram of digital joystick
User interface devices
JOYSTICK
analog joystick
User interface devices
JOYSTICK
Construction of analog joystick
User interface devices
JOYSTICK
Schematic diagram of analog joystick
User interface devices
JOYSTICK
Schematic diagram of analog joystick
User interface devices
JOYSTICK
Construction of contactless optical joystick
User interface devices
JOYSTICK
Construction of contactless Hall Effect joystick
• single, dual & triple axis
• output voltage 0 ÷ 5V DC
(proportional to handle travel)
• center voltage 2.5 V DC
• joystick handle travel
– X,Y axis ±18º from center
– Z axis ±40º
• linearity ±2% FS
• MTBF 3,000,000 cycles, normal
operation
• also USB version
User interface devices
JOYSTICK
Construction of contactless Hall Effect joystick
-MLX90333 monolithic IC
• absolute 3D position sensor
• selectable outputs: analog
(ratiometric), PWM, serial protocol
• 12 bit angular resolution
• applications
• 3D position sensor - joystick
• 4-Way scroll key - joypad
• Man Machine Interface Device
- linear position sensor
User interface devices
JOYSTICK
Construction of contactless Hall Effect joystick MLX90333
Block Diagram
(Analog & PWM)
Block Diagram
(Serial Protocol)
User interface devices
JOYSTICK
Construction of contactless Hall Effect joystick
-MLX90333 monolithic IC
User interface devices
JOYSTICK
Construction of force sensitive joystick
• force sensitive (izometric)
consists of a force sensitive
spring fixed into a base and strain
gauges bonded to the spring
• strain gauges are connected to
form two half Wheatstone bridges
• analogue output is proportional to
applied force
• typically a movement less than
1mm for full scale output
User interface devices
JOYSTICK
Construction of force sensitive joystick
Benefits
• no moving parts - extreme
reliability 10 000 000 full scale
cycles in both directions
• require less space for mounting
• no space is needed to
accommodate an arc of travel
• lends itself to miniaturization
• interface none or USB
User interface devices
JOYSTICK
Construction of force sensitive joystick
Specification
• resistance (half bridge) 325 Ω nominal
• sensitivity 95 mV/N
• maximum non-linearity 1% FS
• maximum hysteresis at zero 0.3% FS
• full scale force 10.5N nominal
User interface devices
JOYSTICK
Construction of force sensitive joystick- IBM trackpoint
User interface devices
JOYSTICK
Construction of joystick with feedback capability
User interface devices
JOYSTICK
• Force feedback is an all-encompassing term used to
describe input devices equipped with actuators, motors
and resistance-inducing elements that are used for
exerting vibration-based forces
Input devices
Scanner
Scanner is a device that optically scans images, printed text,
handwriting, or an object, and converts it to a digital form
Input devices
The scanning process
•
Division the image to small areas and
identifying the degree of gray or color
•
The scanned image is illuminated by
light source with continuous spectrum
– CCFL (cold-cathode fluorescent
lamps)
– halogen lamp
– xenon lamp
– Contact Image Sensors (CIS) with
LEDs
Input devices
The scanning process (continued)
•
•
Light is reflected from given area and falls on light sensitive elements
– photomultipler tubes
– CCD charge coupled device semiconductor elements (simpler, cheaper
and maintenance free)
The device has a row of photosensitive elements determining the width of
the scanned image strip
CCD line sensor
Input devices
The scanning process
– electric potential of the photosensitive element is proportional to
the light intensity which depends on the level of gray of scanned
image
– potential is amplified and converted into a digital signal
•
Scanning of color images
– additive color model: RGB (Red Green Blue) the distribution of
the intensity values of the three component of image is required
– three running scanning (cheaper and easier)
• scanning runs three times, separately for each of the
components
• in each running in the optical track is another filter
• final image results by addition of 3 images
Input devices
The scanning process
• Scanning of color images
– one running scanning
• the image is viewed once
• 3 systems:
– dispersion of light by prism
reflected light after dispersion by prism goes on a
precisely placed photosensitive elements
– translucent mirror
using the mirrors reflected light is separated into three
beams; in the track of each is placed color filter
– three sources of light
consists of set of red, green and blue LEDs strobed for
illumination image
Input devices
Types of scanners
Flat bed scanners (CCD)
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composed of a glass pane under
which there is a bright light and a
movable light source and a
moving optical array
CCD-type scanners typically
contain three rows of sensors with
red, green, and blue filters
image is acquired by placing the
document face down on the glass
the scanner head lies beneath the
glass and moves along the item,
capturing the image
Input devices
Types of scanners
Flat bed scanners (CIS)
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Contact Image Sensors (CIS) place the
image sensor in near direct contact
with the object to be scanned in
contrast to CCD scanners
CIS consists of a linear array of
detectors, covered by a focusing lens
and flanked by red, green, and blue
LEDs for illumination
•
CIS devices typically produce lower
image quality compared to CCD
•
CIS contact sensor is smaller and
lighter than a CCD line sensor, and
allows optical elements to be included
in a compact module
•
CIS consumes less than a tenth of the
electricity used by CCD
Input devices
Types of scanners
Sheetfed scanners
OCR A4 Paper Scanner-Document
• Scanning sensor CIS
• Resolution 600 dpi
• Media Width 2.2'' to 14''
Scan Length 14''
• Scan Mode 24 bit color, 8 bit gray,
1 bit black & white
• Scan time A4, 600 dpi / color 123s
Fujitsu ScanSnap S1500
• Max Scan Speed 20 page/min (color)
• Resolution 600 x 600 dpi
• Color Depth 24-bit
• Grayscale Depth 256
• One button PDF creation
• Duplex Scanning
• Automatically recognizes document
size from 2 x 2” to 8.5 x 14.17”
Input devices
Types of scanners
Drum scanners
•
reflective and transmissive
originals are mounted on an
acrylic cylinder, the scanner drum,
which rotates at 1000-1500 rev/s
•
drum scanners capture image
information with very sensitive
photomultiplier tubes (PMT) which
move linearly from left to right
•
color drum scanners use three
matched PMTs, whith red, blue,
and green light, respectively
•
drum scanners produce a highquality scanned image used for
high-end reproductions, such as
archiving photographs in
museums
Input devices
Types of scanners
Handheld scanners
•
hand scanners are manual devices
that are dragged across the surface of
the image to be scanned.
•
scanning documents in this manner
requires a steady hand, as an uneven
scanning rate would produce distorted
images
An example
•
A4 Color hand scanner,
standard resolution : 300x300 dpi
high resolution: 600x600 dpi
Scanning sensor CIS
power source: 2*AA battery
USB2.0
16 GB memory
Input devices
Types of scanners
All-in-one Scanners
• An all-in-one (AIO) device
combines the functionality of
multiple into one physical
piece of hardware (scanner,
printer, copier and fax)
• An AIO is a small desktop
unit, designed for home or
home office use
• SOHO - a large desktop or
small freestanding unit,
designed for Small
Office/Home Office use
Input devices
Technical details of scanners
Flat bed scanners (CCD)
lamp
inverter
Input devices
Technical details of scanners
Flat bed scanners (CCD)
step motor
mirrors
Input devices
Skanner parameters
•
tonal resolution
The number of bits necessary to describe the shade of single bit image (1-36). .
•
optical resolution
The number of points recognized by the scanner per inch (ppi). For flatbed
scanners, resolution in one axis defines the number of elements of the CCD. In
second axis resolution depends of resolution of moving head mechanism.
Sometimes there are distinguish the term of the mechanical resolution.
Optical resolution of flatbed scanner is from 600 to 5000 ppi and for drum
scanner between 3000 and 24 000.
•
output resolution
Scanner resolution possible to obtain by interpolation.
•
optical density
Otherwise dynamic range ; the ratio of the brightness of the brightest
distinguishable point to the brightness of the darkest point. Decimal logarithm of
reflection coefficient. Values from 0 D to 4 D. 2D -> bright points are 100 times
brighter then dark points. The best scanners (drum) about 3.7 D.
Input devices
Scanner interfaces
– parallel port IEEE1284,
The slowest of the transmission method.
– SCSI bus
You can use an existing in computer or usually use additional card.
– USB bus
Favourable ratio of price, speed and ease of use.
– Firewire bus
Fastest, used in high-end scanners
Input devices
3D scanners
– contact
– non contact
• active
• passive
Input devices
3D scanners
• a device that analyzes a real-world object
to collect data on its shape and its
appearance (i.e. color)
• collected data can be used to construct
digital three dimensional models
• 3D data are useful for a wide variety of
applications
– reverse engineering
– quality control
– entertainment industry - movies and
video games
– documentation of cultural artifacts
Input devices
3D contact scanners
• contact 3D scanners probe the
object through physical touch
• the scanner mechanism may
have two different forms
– a carriage system with rigid
arms; best with flat profile
shapes or simple convex
curved surfaces
– an articulated arm with rigid
bones and high precision
angular sensors; ideal for
probing interior spaces
Input devices
3D contact scanners
A carriage system
Input devices
3D contact scanners
An articulated arm
Input devices
3D contact scanners
An articulated arm
Input devices
3D Non-contact active
scanners
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active scanners emit some kind of radiation
or light and detect its reflection
possible types of emissions include light,
ultrasound or x-ray
3D laser scanner uses laser light to probe
the object
the scanner finds the distance of a surface
by measuring the round-trip time of a pulse
of laser light
the scanner scans its entire field of view one
point at a time by changing the direction of
view to scan different points
the view direction can be changed either by
rotating the range finder itself, or by using a
system of rotating mirrors
Input devices
3D Non-contact passive scanners
• passive scanners do not emit any kind of
radiation themselves, but instead rely on
detecting reflected ambient radiation
• most scanners of this type detect visible light,
infrared could also be used
• stereoscopic systems usually employ two
video cameras, slightly apart, looking at the
same scene
• by analyzing the slight differences between
the images seen by each camera, it is
possible to determine the distance at each
point in the images
Input devices
3D Non-contact passive scanners
Scanning time 8 h, CAD model generation 2 week
Input devices
3D Non-contact passive scanners
Input devices
Bar code readers
•
specialized scanners to read the images made of light and dark
various widths bar
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•
•
Construction
– electrooptical lightening system
• LED
• laser light source (a range of few meters)
– system of measuring the reflected light beam
• single CCD
• line CCD
• CCD array
Desktop and manual readers
Parameters
– distance
– angle of work
Input devices
Bar code readers - laser
The most well known scanner type. It uses
a red diode laser to read the reflectance of
the black and white spaces in a barcode.
Motorola LS 3408ER
Long Range scanner excellent for industrial
environments.
•Specification
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scanner type - retrocollective
flexible working range: 15 cm to 14.6 m
light source: 650 nm visible laser diode
scan repetition: 36 scans per second
tilt +/- 10 °, pitch: +/- 65 °, skew +/- 60 °
minimum element width: 0,18 mm
(7 mil)
Input devices
Bar code readers - Linear Imager
Linear imager scanners instead of reading
reflected light from the laser, they take a
picture of the barcode. It then analyzes
this image to extract the information from
the code.
Honeywell Hyperion 1300g
The ability to read to 18" on 13 mil bar codes
and high density bar codes in a single device
• Specification
– scan pattern - single line
– decode capabilities - reads standard
1D and GS1 DataBar symbologies
– scan rate up to 270 scans per second
– print contrast 20% minimum
reflectance difference
– pitch +/- 65°, skew +/- 65°
Input devices
Bar code readers - 2D Area Imager
Like linear imagers, full 2D imagers also
capture an image to analyze. These
scanners can read any type of barcode:
1D, stacked, and 2D. The orientation of
the barcode isn't important when reading.
Honeywell Xenon 1900
Reads standard 1D, PDF, 2D, Postal and
OCR symbologies
• Specification
– scan pattern - area image (838 x 640
pixel array)
– pitch +/- 45°, skew +/- 65°
– can also read barcodes off of any
surface including a monitor or phone
screen.
Input devices
Bar code readers - Terminology
• Density—the number of narrow bars
and spaces represented in the symbol
divided by the total width of the symbol
• Symbology—the combination of bar
code characters and spaces which
provide information
• Read window—the region within which
the scanner is capable of reading bar
code
• Focal point— the specific measured
distance between the scanner and the
label at which a bar code can be
optimally read.
• Depth of field—the region in front of and
behind the focal distance within which
the scanner can still read bar codes.
Input devices
Bar code readers Terminology
• Tilt—Rotation of a bar code symbol
about an axis Z perpendicular to
the substrate.
• Pitch—The rotation of a bar code
symbol about an axis X
perpendicular to the bars.
• Skew—the rotation of a bar code
symbol about an axis Y parallel to
the bars.
• Omnidirectional—a scanner that
can read in both horizontal and
vertical label positions, or any
position between horizontal and
vertical.
• Scan rate—scanner speed, in
scans per second.
Input devices
Bar code readers - Code 39 (Code 3 of 9, Barcode39)
*
8
6
7
narrow spaces (white)
wide spaces (white)
narrow bars (black)
wide bars (black)
5
3
0
separator
0
1
9
*
* = 0-0110
0 = 00-110
1 = 10-001
2 = 01-001
3 = 11-000
4 = 00-101
5 = 10-100
6 = 01-100
7 = 00-011
8 = 10-010
9 = 01-010
* = 0-0110
A-Z
Input devices
Bar code readers - barcode EAN13
(European Article Number)
Country Code
00, 01, 02... 09 USA
400, 401, ... 440 Germany
50 Great Britain
590 Poland
594 Romania
599 Hungary
Country
Code
Manufactures
ID
Product
ID
Check
Digit
Input devices
Bar code readers - matrix code (2D barcode, 2D code)
timing pattern
finder pattern
10 x 10 - 144 x 144
Input devices
Bar code readers - matrix code application
• Marking small items - ability to encode fifty characters in a
symbol that is readable at 2 mm2 square
• The United States of America's Electronic Industries Alliance (EIA)
recommends using Data Matrix for labeling small electronic
components
• Aerospace where quality control is tight and a black market exists
for counterfeit parts. Data Matrix codes identify manufacturer ID,
part number and a unique serial number
• Data Matrix codes are becoming common on printed media such
as labels and letters
• Healthcare industry
• Data Matrix codes can also be read with smartphones - when
people scan the barcode, they instantly can online see
information about a product on custom internet site
Input devices
Image sensors
• Are used in several types of peripheral devices
– scanners
– bar code readers
– optical mouse
– camcorders and digital cameras
• Basic types of image sensors
– CMOS
– CCD
– photomultiplier
Input devices
Image sensors
• CMOS sensors
– CMOS structure with photodiodes and located near
transistors, produced by using classic technology (low
cost)
– part of the photons strikes in the transistors amplifier and
not in photodiode - low resolution
– sensor sensitive to noises
– CMOS can potentially be implemented with fewer
components, use less power, and provide faster readout
than CCDs
Input devices
Image sensors
• CMOS sensors
Input devices
Image sensors
• CCD sensors
Input devices
Image sensors
• CCD sensors
– electric charge proportional to the illumination is drained
from one side of the matrix
• fewer electrical connections
• better resolution (no transistor amplifiers and their pins)
– high power consumption in comparison with CMOS
– higher resolution and quality due to the mature technology
resulting from long presence on the market
Input devices
Image sensors
• Photomultiplier sensors (PMT)
Input devices
Image sensors
• Photomultiplier sensors (PMT)
– photomultiplier tubes,extremely
sensitive detectors of light in the
ultraviolet, visible, and near-infrared
ranges of the electromagnetic
spectrum
– these detectors multiply the current
produced by incident light by as much
as 100 million times (i.e., 160 dB)
– the combination of high gain, low
noise, high frequency response, and
large area of collection has earned
photomultipliers an essential place in
high-end image drum scanners
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