Multimedia Input Devices
Are devices which transfer sound, images, video or a combination therein to or from a computer system. Multimedia devices can be either input or output devices and common types of this device are digital cameras and sound devices.
Digital cameras capture and store photographic or video images through the use of electronic signals. The captured files are most often stored on removable memory cards, although they may sometimes be stored on embedded cards or optical discs.
It’s possible to transfer, print, save or otherwise work and edit with the information stored on the digital camera or removable memory by connecting the camera or storage media to a computer system.
If the camera has a removable storage media, it’s possible to transfer the data by connecting the card itself to the system through a media card reader.
Camcorders & Video Recording Cameras
Video recording cameras work in very much the same way as other digital cameras. Often, data is stored on removable or optical media and the data is captured through analogue or digital electronic signals.
As with digital cameras, video recording cameras can often be connected to a computer system through a USB or Firewire port. However, some professional grade cameras may use tapes or disks that will need an alternate transfer method, sometimes additionally requiring digitisation.
A webcam, or Web Camera, is used to send a continual video feed or periodic images to a website for display. In the majority of cases, webcams capture the data in the form of JPEGs (images) or MPEGS (video) before uploading them to a web server.
Webcams are also used a lot within instant messaging software (such as Skype) and by some video applications. In some cases, companies and corporations might use webcams as a security measure.
As with digital cameras and camcorders, webcams are very often connected to computer systems through USB or Firewire ports.
A computer microphone allows audio data to be sent into a computer system. Normally this would be either for the data to be recorded or for use in ‘real time’, such as an audio feed that accompanies a webcam or video conference feed.
In the vast majority of cases, the microphone is connected to the computer system through a microphone jack or sound card. If the sound-card has colour coded ports, the microphone connection will be pink in colour. Otherwise, the ports will be marked with the word ‘mic’ or with a small microphone icon.
Most microphones have a 1/8-inch phono plug built into the cable to enable connection.
Optical Input Devices
Optical Input Devices offer a way for users to be able to transfer information from a paper, ‘hard-copy’ source into a digital format that the computer system is able to work with.
Scanners are used to take a photo-identical copy (scan) of a physical copy of any document (known as ‘hard-copy’) and create a digital format copy which can be stored, transfered or edited on a computer system.
A scanner works in a similar fashion to a photocopier but, ordinarily, has a much smaller footprint. Scanners can be attached directly to a computer system to import the scanned copies of documents. With the correct software, imported documents can be edited, manipulated for transmitted.
Typically, a scanner is connected to a computer system through a USB or High-Speed USB connection. In todays world, scanners are very often incorporated into multi-function printers.
Barcodes are able to provide a simple and inexpensive method of encoding textual information that can be easily read by electronic readers.
A bardcode reader scans a light source across the barcode and converts the pattern of reflected light into an electronic signal that is then decoded back into it’s original data format.
There are currently four styles of barcode reader available:
- Pen-type readers (also known as barcode wands)
- Laser scanners
- Charge Coupled Device (CCD) readers
- Camera-based readers
As with the majority of peripheral input devices, barcode scanners are connected to computer systems through USB connections.