A USB pen camera is a pen with a camera hidden inside that typically comes apart to allow the camera to connect to a computer through a USB port. Typically, the pen is designed to be functional both as a pen and a camera at the same time, but some may not be able to record while the pen is writing. This type of camera is often advertised for spy activities, but many models are not able to record with enough detail to be of much use in professional spy operations. In many cases, a USB pen camera is able to record both video and sound, so it can be used for recording memos and personally relevant information as well.
The basic design of a USB pen camera includes a pen with a small supply of ink, a recording mechanism, and a storage device, all of which fit within the body of a normal pen. Usually, the camera's aperture is small enough to be nearly invisible, although it may be more conspicuous in some designs. It is important that the camera's opening and microphone are not in a place that the hand would normally cover when writing. They must also be above the pen's clip so the camera can be used while being held in a chest pocket. Otherwise, the internal design is relatively open to innovation.
Storage within a pen is problematic due to the small space, but as technology advances, more storage becomes possible. It is usually possible to fit as much memory inside a USB pen camera as it is possible to fit within a stick USB drive. Sometimes, lowering the quality of the recording can make it possible to fit a longer video on the pen, but this is not a good idea if the video must be clear. Still images are also a good option if a user needs to record over a long period of time.
For secret recordings, it is important that the USB pen camera be at least partially functional as a pen. It is not, however, usually very easy to take clear recordings while writing with the pen. Audio messages, such as voice memos to oneself or recordings of others, can usually be taken while the pen is being used for writing. Video, on the other hand, is highly disturbed by the act of writing and is therefore best taken while the pen is clipped to the user's shirt pocket. When using this type of pen, it is important to think about how the final recording will look or sound while the recording is being made so that the resulting recording will be usable.
