The document provides an overview of various types of barcode readers, including pen wands, CCD scanners, and laser scanners, along with their advantages and disadvantages. It also discusses the function and technology behind flatbed, sheet-fed, handheld, and 3D scanners, detailing their applications, benefits, and limitations. Overall, it highlights the importance of these devices in efficiently capturing and processing information in various fields.

1. By:
Mahnoor Shehzad
Zuha Mazhar
Zainab Arif
X-S

2.  A barcode reader, also called a price scanner or point-of-
scale scanner, is an electronic device
for reading printed barcodes. Like a flatbed scanner,
it consists of a light source, a lens and a light sensor
translating optical impulses into electrical ones.

3.  There are five basic types of barcode readers..
- pen wands
- slot scanners
- charge-couple device (CCD) scanners
- image scanner
- laser scanners

4.  A pen wand is the simplest barcode reader. It consist of a
light source and a photo diode that are placed next to each
other in the tip of a pen or wand. To read a bar code, you
drag the tip of the pen across all the bars in a steady even
motion. The photo diode measures the intensity of the
light reflection back from the light source and generates a
waveform that is used to measure the widths of the bars
and spaces in the bar code.
 Dark bars in a barcode absorb light and white spaces reflect
light so that the voltage waveform generated by the photo
diode is an exact duplicate of a bar and space pattern in the
barcode. This wave form is decoded by the scanner in a
manner similar to the way Morse code dots and dashes are
decoded.

5.  A slot scanner remains stationary and the item with
the bar code on it is pulled by hand through the slot.
Slot scanners are typically used to scan barcodes on
identification cards.

6.  A CCD scanner has a better read-range than the pen
wand and is often used in retail sales. Typically, a CCD
scanner has a ‘gun’ type interface and has to be held no
more than one inch from the bar code. Each time the
bar code is scabbed, several readings are taken to
reduce the possibility of errors.
 A disadvantage of the CCD scanner is that it cannot
read a bar code that is wider than its input face.

7.  An image scanner, also called a camera reader, uses a
small video camera to capture an image of the bar code
and then uses sophisticated digital image processing
techniques to decode the bar code. It can read a bar
code from about 3 to 9 inches away and generally costs
less than a laser scanner.

8.  A laser scanner, either hand-held or stationary, does
not have to be close to the bar code in order to do its
job. It uses a system of mirros and lenses to allow the
scanner to read the bar code regardless of orientation,
and can easily read a bar code up to 24 inches away. To
reduce the possibility of error, a laser scanning may
perform up to 500 scans per second. Specialized long-range
laser scanners are capable of reading a bar code
to 30 feet away.

9.  There are five basic advantages of barcode readers…
- Speed
- Accuracy
- Data Integrity
- Ease of Implementation
- Cost Effectiveness

10. - System failure may cost more delays
- Scratched or crumpled barcodes may cause problems
- Data must be coded in the barcode
- In laser scanning, durability and cost are two
disadvantages.

11.  A scanner is a device that captures images from
photographic prints, posters, magazine pages, and
similar sources and converts them into digital data for
computer editing and display.

12.  The document is placed on the glass plate and the cover is closed. The inside of
the cover in most scanners is flat white, although a few are black. The cover
provides a uniform background that the scanner software can use as a reference
point for determining the size of the document being scanned. Most flatbed
scanners allow the cover to be removed for scanning a bulky object, such as a
page in a thick book.
 A cold cathode fluorescent lamp (CCFL) is used to illuminate the document.
 The entire mechanism (mirrors, lens, filter and CCD array) make up the scan
head. The scan head is moved slowly across the document by a belt that is
attached to a stepper motor. The scan head is attached to a stabilizer bar to
ensure that there is no wobble or deviation in the pass. Pass means that the
scan head has completed a single complete scan of the document.
 The image of the document is reflected by an angled mirror to another mirror.
In some scanners, there are only two mirrors while others use a three mirror
approach. Each mirror is slightly curved to focus the image it reflects onto a
smaller surface.
 The last mirror reflects the image onto a lens. The lens focuses the image
through a filter on the CCD array.
 Most scanners today use the single pass method. The lens splits the image into
three smaller versions of the original. Each smaller version passes through a
color filter (red, green & blue) onto a discrete section of the CCD array. The
scanner combines the data from the three parts of the CCD array into a single
full-color image.

13.  Flat Bed Scanner
 Sheet-fed Scanner
 Handheld Scanners

14. These are also called desktop scanners flatbed scanners are
the most versatile and popular format. These are capable of
capturing color pictures, documents, pages from books and
magazines, and, with the right attachments, even scan
transparent photographic film.
 Advantages:
They are widely known for their high quality scans.
They are extremely easy to use, especially for new users.
 Disadvantages:
They’re often large and bulky and tend to take up more
room than other scanners.
They are more expensive as compared to other scanners.
 Use of Application: Offices, Homes

15. These are similar to flatbed scanners except the document is
moved and the scan head is immobile. A sheet-fed scanner looks
a lot like a small portable printer.
 Advantages:
Sheet-fed scanners are great for scanning large documents like
manuals or transcripts.
A big advantage of a sheet-fed scanner is that it is smaller in size
than a flatbed scanner and uses much less desk space.
They are portable. Good for travelling.
 Disadvantages:
They are not good for scanning images because the document is
actually moving and the scanner itself remains stable. This is the
precise reason that these scanners are not very good at scanning
any type of graphics. Because the image is zooming past so fast,
the scanner must capture a moving target. As a result, the quality
and clarity of the image suffers.

16. These use the same basic technology as a flatbed scanner, but rely
on the user to move them instead of a motorized belt. This type
of scanner typically does not provide good image quality.
However, it can be useful for quickly capturing text.
 Advantages:
Small (portable)
Inexpensive
Disadvantages:
Poor quality.
You have to manually move it
Need to keep your hand steady or else, the image is messed up.
 Application of use: Used in warehouses and grocery stores to
track inventory, but variations of handheld scanners are used in
offices, homes and schools. Some handheld scanners are even
made to be taken in a briefcase or suitcase for mobile scanning
needs on the go.

17.  A 3D scanner is a device that analyzes a real-world object or
environment to collect data on its shape and possibly its
appearance (i.e. colour). The collected date can then be
used to construct digital three dimension models.
 Many different technologies can be used to built these 3D-scanning
devices; each technology comes with its own
limitations in the kind of objects that can be digitized are
still present, for example, optical technologies encounter
many difficulties with shiny, mirroring or transparent
objects. For example, industrial computed tomography can
be used to construct 3D models, applying non-destructive
testing.

18.  Collected 3D data is useful for a wide variety of
applications. These devices are used extensively by the
entertainment industry in the production of movies
and video games. Other common applications of this
technology include…
-industrial design
-orthotics
-prosthetics
-reverse engineering
-prototyping
-quality control

19.  Quickly capture all of the physical measurements of
any physical object.
 Save time in design work.
 Ensure parts will fit together on the first try.
 Capture engineering optimizations inherent in
manufactured parts.
 Utilize modern manufacturing on parts that we
originally manufacture before CAD Compare ‘a-designed’
model to ‘as-built’ condition of
manufactured parts of 3D scanners.

20.  The size of a 3D scanner can be as big as a small
refrigerator
 The price of a 3D scanner is expensive. Some small
businesses cannot afford them.
 Non-contact 3D scanners can be very slow in scanning
objects
 The clarity of the image may not be the best.