It tells brief information about microscope

1. MICROSCOPE
SALAL MOHAMMAD
B.OPTOM, 2ND YEAR

2. CONTENTS
HISTORY
INTRODUCTION
PARTS
TYPES
MAGNIFICATION POWER
RESOLVING POWER
USES

3. HISTORY-
• Zacharias Janssen invented the first compound
microscope in 1590.
• Antony van Leeuwenhoek (1632-1723) is credit with
developing the first microscope.
• Antony was the first to see bacteria ,red blood cells,
yeast and so much more.
• Antony is the father of microscope.
• Robert Hooke’s famous “Micrographia”
is published ,which studies by the using microscope.
• Joseph Jackson Lister,1830 discovers that using weak
lenses together at various distance provided clear
magnification.

4. INTRODUCTION-
• Microscope is an optical instrument used to see very small
object.
• Microscope is derived from Greek word-‘micro’ means tiny or
small, and ‘scopian’ means to view.
• Microscopic means invisible to the eye unless aided by a
microscope.

5. TYPES-
• Microscope is mainly 3 types-
 Optical microscope
 Electron microscope
 Scanning probe microscope
OPTICAL MICROSCOPE
It is of also 2 types-
 Simple microscope
 Compound microscope

6. SIMPLE MICROSOPE
Introduction-
• It is a single convex lens of lesser focal length.
• It is also called magnifying glass /reading lens.
• A convex lens of short focal length can be used to magnified
image of a small object.
Principle –
• When a small object is placed b/w the optical centre and focus
of a convex lens .
• It is virtual, erect and magnified image is formed on the same
side of lens.
• The lens is held close the eye and the distance of the object is
adjusted till the image is formed at least distance of distinct
vision from the eye.
• The least distance of distinct vision is 25cm.

8. Uses –
• Jewelers and watch makers makes uses of a convex lens or
simple microscope.
• In science lab. a magnifying glass is used to see slides and to
read the vernier scale attached to the instruction.
• The use of magnifying glass enables us to place the objects
close to the eye, making it appear bright and yet clearly visible.

9. COMPOUND MICROSCOPE
Introduction-
• It’s consist of 2 converging lenses called objective lens and eye
piece lens.
• It’s formed intermediate image is real and enlarge.
• And final image is formed at infinite.
• Feye lens > Fobjective lens (Dia.) eye lens >(Dia.)objective lens
Objective lens-
• It is having short focal length ,short aperture and facing the
object. It's k/a objective lens..
Eye piece lens-
• It is having having large focal length, large aperture and facing
towards eye.it’s k/a eye piece lens.

10. Principle –
• When a small object is placed just outside the focus (Fo) ,of
object lens.
• It’s real ,inverted and magnified image is produce on the other
side of the lens beyond 2Fo.
• The image produce by the object lens act as an object from the
object lens is so adjusted that the final image is formed at the
least that the final image is formed at the least distance of
distinct vision from the eye.

12. Eyepiece
Body Tube
Revolving Nosepiece
Arm
Objective Lens
Stage
Stage Clips
Coarse Focus
Fine Focus
Base
Diaphragm
Light

13. PARTS OF MICROSCOPE FUNCTION
Coarse adjustment knob General focus particularly for 10X lens
Fine adjustment knob Fine focus ,particularly for 100X lens
Arm Infrastructure of the microscope
Power switch/brightness
control
On /Off switch for light ,changes intensity
Base Infrastructure of the microscope
Condenser knob Condenser movement
Iris diaphragm lever Control of cone of light coming through condenser
Objective lens Magnification of 10X, 40X, and 100X
Revolving nose piece Attachment of objective lens
Ocular eye piece lens Magnification of 10X
Stage holder Hold slide in place
Stage holder knob Movement of stage ,2 directions
Stage Placement of slide

14. • General Procedures
• 1. Make sure all backpacks and materials are out
of the aisles and off the tops of desks.
• 2. Plug your microscope in to the outlet.
• 3. Store with cord wrapped around microscope and
the scanning objective clicked into place.
•
• 4. Carry by the base and arm with both hands.

15. Let’s give it a try ...
1 – Turn on the microscope and then rotate the nosepiece to click the red-banded
objective into place.
2 – Place a slide on the stage and secure it using the stage clips. Use the coarse
adjustment knob (large knob) to get it the image into view and then use the fine
adjustment knob (small knob) to make it clearer.
4 – When you are done, turn off the microscope and put up the slides you used.
3 – Once you have the image in view, rotate the nosepiece to view it under different
powers. Draw what you see on your worksheet!
Be careful with the largest objective! Sometimes there is not enough
room and you will not be able to use it!

16. Magnification
Your microscope has 3 magnifications: Scanning, Low
and High. Each objective will have written the
magnification. In addition to this, the ocular lens
(eyepiece) has a magnification. The total magnification
is the ocular x objective

17. Magnification of simple microscope
M=1+d/f
Magnification of compound microscope
M= -Vo/Uo(1+d/fe)

18. RESOLVING POWER
The ability of an optical instrument or type of film to separate or
distinguish small or closely adjacent images.
It is 3 types-
Angular resolution
Spectral resolution
Optical resolution
Resolving power of microscope-
R.P=2usinØ/1.22ʎ

19. Difference b/w Simple and Compound microscope
SIMPLE MICROSCOPE COMPOUND MICROSCOPE
 It has only one type of lens i.e. objective
lens ,eye piece is absent.
 It had both types of lens ,objective a
well as eye piece lens.
 It has no variable magnification.  It has variable magnification ,10X ,40X,
100X
 The image is formed erect ,enlarged
and virtual.
 The image formed is enlarged ,inverted
and virtual.
 Refractive error can’t be corrected by
this microscope.
 Refractive error can be corrected
through this microscope.
 Vernier callipers is not present in
simple microscope
 Verniers callipers is present in
compound microscope.