Electric-component transferring apparatus, method of taking images of electric components, and electric-component mounting system

An electric-component mounting system comprising:

• a circuit-substrate supporting device which supports a circuit substrate;
• an electric-component supplying device which supplies electric components;
• at least one pair of component holders each of which sucks and holds an electric component supplied from the electric-component supplying device, by applying vacuum to the electric component;
• a movable member which supports said one pair of component holders;
• an image taking device which has a square range of view and which takes respective images of the electric components held by said one pair of component holders;
• an error detecting and correcting device which is connected to the image taking device and which detects and corrects, based on the taken image of each of the electric components held by said one pair of component holders, at least one of (a) a positional error of said each electric component from a reference position in at least one direction parallel to a plane on which the circuit substrate is supported by the circuit-substrate supporting device and (b) an angular error of said each electric component from a reference angular position about an axis line perpendicular to the plane, so that the electric components are mounted on the circuit substrate after said at least one of said positional error and said angular error of said each electric component is corrected;
• a moving device which moves the movable member from a component-receive position where each of the component holders of said one pair is opposed to the electric-component supplying device, to a component-mount position where said each component holder mounts the electric component on the circuit substrate supported by the circuit-substrate supporting device, via an image-take position where the moving device stops the movable member such that respective axis lines of the component holders of said one pair that are parallel to each other perpendicularly intersect one of two diagonal lines of the square range of view of the image taking device, at respective positions which are axis-symmetric with each other with respect to an optical axis of the image taking device, so that the image taking device simultaneously takes, in a direction parallel to said respective axis lines of the component holders, the respective images of the electric components held by the component holders.