COMPUTER HARDWARE (INPUT DEVICES

    
COMPUTER HARDWARE:
  Computer hardware refers to the physical parts of a computer and its related                     devices. Internal hardware devices include motherboards, 
   hard drives and memory.    The eternal hardware devices include monitors,    keyboards, mice, printers and scanners.

     The internal hardware parts of a computer are often referred to as components, while the external components are referred to as peripherals. 
    Together, they all fall under the category of computer hardware. The computer hardware can be categorized into the following;

Ø     Input Devices

Ø     Output Devices

Ø            System Unit

Ø     Storage Devices

Ø          Communication Devices

                             INPUT DEVICES

In computing, an input device is any peripheral (piece of computer hardware equipment). Used to input data into the computer and also interact with the computer.

   Ø  KEYBOARD.

A keyboard is a peripheral device that enables a user to input text into a computer allowing the user to control and interact with the computer.

  

  Ø  POINTING DEVICE.

A pointing device is a hardware input device that allows the user to move the mouse cursor in a computer. Using a pointing device allows you to point at or manipulate any object or text on the screen.

 Ø   MOUSE

A computer mouse (plural: mice) is an input device that is most often used with a personal computer.

A mouse is a handheld pointing device used to position a cursor on a computer screen. This allows the user to select items stored on a computer and, subsequently, perform actions on those items.

Moving a mouse along a flat surface can move the on-screen cursor to different items on the screen. Items can be moved or selected by pressing the mouse buttons (called clicking).

Ø           TRACK BALL.

A track ball is a computer input device that serves as an alternative to a computer mouse or touch pad for moving the pointer around a computer screen.

The track ball is a movable ball mounted on top of stationary device that can be rotated using your fingers or palm. The trackball looks like a mouse turned upside down.

Instead of moving the mouse around on the desktop, you move the trackball with the tip of your fingers.

The trackball is not as accurate as a mouse but it is a good alternative when desktop space is limited. Trackballs can be either wired or wireless.

   Ø  TOUCHPAD

A touchpad is a small flat surface over which you slide your finger using the same movements as you would with a mouse.

A touchpad or "trackpad" is a flat control surface used to move the cursor and perform other functions on a computer. Touchpads are commonly found on laptops and replace the functionality of a mouse. A touchpad is designed to be controlled with your finger.

Ø   TOUCH SCREEN.

A touch screen is a video display screen that has been sensitized to receive input from the touch of a finger.

When a touch screen is touched by a finger or stylus, it registers the event and sends it to a controller for processing.

A touch screen may contain pictures or words that the user can touch to interact with the device.

All touch screens are sensitive to pressure.

   Ø  JOYSTICK

In computers, a joystick is a cursor control device used in computer games and assistive technology.

The joystick, which got its name from the control stick used by a pilot to control the ailerons and elevators of an airplane, is a hand-held lever that pivots on one end and transmits its coordinates to a computer.

•      DIGITIZER: is a device used to convert analog signals into digital signals.

A digitizer uses an electronic pen that can convert drawings and photos to a digital data.

In the case of our cell phones, this device would be the glass that covers the LCD

Ø              SCANNER:

A scanner is an electronic device which can capture images from physical items and convert them into digital formats, which in turn can be stored in a computer, and viewed or modified using software applications. A scanner is used to send data/information onto a computer

Ø                                            BAR-CODE READER:

A barcode reader, also called a price scanner or point-of-sale ( POS ) scanner, is a hand-held or stationary input device used to capture and read information contained in a bar code . ... Barcode scanners can be connected to a computer through a serial port, keyboard port, or an interface device called a wedge.

Barcode readers consist of a light source, a lens and a light sensor that translates optical impulses into electrical ones

Ø                      MICROPHONE: A microphone is a device that captures audio by converting sound waves into an electrical signal.

Microphones are audio input devices that take varying air pressure, waves created by voice or other sound sources and convert them into varying electric signals.

Many micro computers come with inbuilt microphones

Ø                          SPEECH-RECOGNITION:

speech recognition or voice recognition is a computer software program or hardware device with the ability to decode the human voice. Voice recognition is commonly used to operate a device, perform commands, or write without having to use a keyboard, mouse, or press any buttons.

A speech recognition using a microphone as an input device converts a person’s speech into digital signals comparing the electrical patterns produced by the speaker’s voice with a set of pre-recorded patterns stored in the computer. Most of today’s speech recognition packages have a database of about 200,000 words from which they try to match the words you say.

These programs let you accomplish two tasks:

Turn spoken words into typed text and issue oral commands.

Ø                    

            DIGITAL CAMERA:

Digital camera uses a light-sensitive processor chip to capture photographic images in digital form and store them on flash memory cards.

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