COMPOUND

MICROSCOPE

Mr. Govardhan Joshi

Microscope

•Microscope is the combination of two

words; "micro" meaning small and

"scope" meaning view.

•Compound deals with the microscope

having more than one lens.

History

•Optical microscopes are the oldest and simplest of the microscopes.

A 1879 Carl Zeiss Jena Optical microscope

The History • Hans and Zacharias Janssen of Holland in the

59 ’s reated the first o pou d i ros ope

• Anthony van Leeuwenhoek and Robert Hooke

made improvements by working on the lenses

Anthony van Leeuwenhoek Hooke Microscope Robert Hooke

The History

Zacharias Jansen The First Mi ros ope

Diagram Showing Light

Traveling Through The

Microscope

Parts of Microscope

Parts and function of

Microscope Mechanical supporting system

Optical system

Illumination system

Adjustment system

Mechanical supporting system

• Base: Support microscope

• Arm: Supports the tube and connects it to the base

• Revolving nose piece/ turret: holds two or more objective

lenses and can be rotated to easily change power

• Stage: horizontal platform with central opening

• Mechanical stage: gives controlled movement to the object on

the slide

Optical system

• Objective:

• one or more lens held in the position by hollow metal cylinder

• Magnify the object

• They almost always consist of

• 4X- scanning objective

• 10X- low power objective

• 40X- high power objective- retractable

• 100X- oil immersion objective- retractable

• Eyepiece:

• Consist of upper eye lens and lower field lens

• They are usually 10X or 15X power

Illumination system

• Source of light: day light and electric light

• Mirror:

• Reflect light rays from light source to object

• One side is concave and other side is plane

• Concave mirror- used for near light source

• Plane mirror- used for distant source of lighted day light

• Condenser: focus the light onto the specimen

• Diaphragm: used to regulate amount of light passing into the

condenser

• Filter: contain blue and white filter below condenser

Adjustment system

• Coarse adjustment: raises / lowers stage to bring image into

focus

• Fine adjustment: brings image into sharp focus

Other parts

• Power Switch

• Stage Clips

• Stage Stop

• Stage adjustment

• Condenser adjustment

• Rheostat control knob

Use of microscope

Principle:

A focused beam of light passes through the

material under study into the microscope.

Parts of the specimen that are optically

dense and having high refractive index or

are colored when stain cast a potential

shadow which is magnified in to main stage

as it passes into the o server’s eye.

Focusing under low power

• Put the slide on the stage and bring specimen over central

aperture

• Lower the condenser and partly close the diaphragm

• Focus the object using coarse adjustment

• Use fine adjustment as required

Focusing under high power

• Rotate the nose piece to high power

• Adjust the condenser and open the diaphragm to admit

enough light

• Use fine adjustment as required

Focusing under oil immersion

• Focus the object first under low power

• Rotate nose piece to oil immersion objective

• Raise the condenser completely

• Open the iris diaphragm

• Keep a drop of immersion oil

• Use fine adjustment as required