| 摘要 |
An audio-visual unit includes a disc mounting a plurality of discrete image transparencies arranged in a continuous pattern for successive visual display; a record co-axially mounted on the disc includes separate recorded messages corresponding to respective transparencies on the disc. The projector includes an advance mechanism manually operable successively for intermittently rotating the disc thereby to present the transparencies in seriatim for visual display. An indexing mechanism is operated in response to actuation of the advance mechanism for intermittently moving a tone arm to successive positions corresponding to the starting grooves of respective messages on the record. A reset mechanism is connected with the indexing mechanism for locating the tone arm in a position corresponding to the beginning groove of a selected one of said messages; the reset mechanism is automatically actuated either by manually actuating the advance mechanism a predetermined number of times or by moving the advance mechanism to a "load" position. |
