An optical gun for use in combination with computer game and computer simulation systems is provided. The optical gun includes a pistol shaped chassis, a USB computer control circuit, an optical sensor, a set of manual buttons, a trigger, a thumbpad, an optical wheel and a hardware accelerator. A game player grasps the pistol shaped chassis with one hand around a hand grip, while supporting a barrel section with a second hand. The optical wheel is located on the barrel and is manipulated by the player's second hand. The player points the barrel at a video screen of a game system. A pull of the trigger indicates that the player has fired a simulated round within a simulation context. Turns of the optical wheel indicate movement of the game player's virtual location within a simulated game space or volume. The player may press against the thumbpad or actuate one of the buttons to communicate movement within the game scenario, or to transmit other instructions to the computer simulation system. The controller receives information from the game system that specifies the pixel illumination data sequence of the video screen. Alternatively, the optical gun may generate a pixel illumination sequence and thereby impose a screen flash on the video screen via the hardware accelerator. The controller calculates the position of the video screen at which the optical gun was pointed by comparing the time of illumination detection reported by the optical sensor within the period of time that the trigger was pulled against the pixel illumination sequence pattern information provided by the game system. The controller then transmits the calculated position on the screen at which the simulated round firing was intended, and any manipulation or activation of the buttons, the optical wheel or the thumbpad, to the host computer. The game system thereupon integrates the game player's inputs regarding virtual movement within the simulated game space or volume and the simulated firing of rounds within the context of the game simulation. The game player may thus ergonomically explore and interact within a simulated two or three dimensional game space. The optical gun and the game system may incorporate USB Bus and Human Interface Device, or HID, standards into their design, use and architecture.

A pointer remotely points a display screen of a large screen display device. The display screen is picked up by a monitor camera. An image processing unit extracts a feature of the pointer used for pointing based on the resulting image signal to identify the position of the pointing point and the pointer based on the feature. A computer generates information on an object to be displayed at a position pointed by the pointer. The generated information is displayed on a display device (CRT display device or large screen display device) assigned to the pointer. Even when a plurality of pointers are used, the information on the object to be displayed pointed by the pointer is properly displayed.