1. Field of the Invention
The present invention relates to a camera, zooming means, focusing means, motion detection means and a power source provided in combination, and in particular to camera apparatus and a camera system which are capable of performing speed control of a rotating body facilitating tracking of a subject and are preferably used for surveillance, crime prevention and monitoring, and a method for controlling the camera system.
2. Description of the Related Art
A surveillance camera, a security camera or a monitor camera equipped with a zooming function and a focusing mechanism (hereinafter referred to as a composite camera) is known. A composite camera is also known comprising a rotating body (panhead) equipped with a rotating mechanism which can rotate the camera main body in order to keep photographing a subject by changing the photographing direction following the motion of the subject.
In the related art, there is known a composite camera for tracking a subject with a composite camera attached is known which performs speed control dependent on the zooming magnification information held in the camera irrespective of the environment of the location of the rotating body or distance to the subject (refer to, for example, the Japanese Patent Laid-Open No. 145430/1979, pp. 1-2). Also is known a composite camera which adjusts and controls the swivel speed in accordance with the angle of the camera direction with respect to the subject (refer to, for example, the Japanese Utility Model Laid-Open No. 47933/1993, p3).
However, on the former composite camera which performs speed control depending on the zooming magnification information held in the camera alone, it is difficult to track a subject at an optimum speed in case the height of the camera location or distance to the subject has changed.
On the other hand, on the latter composite camera which adjusts and controls the swivel speed in accordance with the angle of the camera direction, there remains the problem: in case the angle of the camera direction is the sole information available, it is possible to capture a subject within the sight but could be impossible to focus on the subject when the distance to the camera changed while the subject was moving.
For example, in a system which operates and controls a plurality of cameras using a same controller, it may be necessary to employ separate operations for separate cameras. The composite camera according to the related art cannot possibly address this problem.