Abstract: A method and an apparatus having a memory device for recording a time-varying image in an optical information record medium having an address of a code track corresponding to the image and reproducing the image therefrom, includes the steps of storing data into the memory device of the relationship between the address of the code track and an address of a time code in correspondence with the image, inputting the address of the time code in correspondence with the image to be recorded or reproduced, converting the inputted address of the time code into the address of the code track based on the data stored in the storing step, and accessing to the medium based on the address of the code track obtained by the converting step to record or reproduce the image in correspondence with the inputted address of the time code.

Abstract: A write laser power setting device for setting a write laser power for writing data on a recording medium, includes first and second oscillators and for producing carrier signals having high frequencies f1 and f2. The carrier signals are added with each other to produce a sum signal which is applied to a laser driver for producing a laser drive signal. The power of the laser drive signal is changed to various levels. Using the laser drive signal, the write/read head writes test signals at preselected areas on the recording medium such that different writing power levels are applied to different preselected areas, respectively. After writing the test signals, the write/read head reads the recorded test signals. From the read signal, an unwanted signal having a frequency f1-f2 is filtered, and the level of the unwanted signal is detected and stored. A minimum level of the stored levels is selected, and a preselected area at which the minimum level reading is obtained is detected.

Abstract: A rotatable slide holder adapted for use in slide projectors is disclosed. The slide holder includes first and second spaced members adapted to grip and maintain a slide to be projected in the space therebetween. Spring loaded screws between the first and second members for rotationally fixing the members relative to one another and for biasing the members toward one another. The first and second spaced members are rotationally coupled to the body of the projector so that the members can rotate about an axis perpendicular to a slide positioned in the space between the members. A drive motor is mounted on the projector body and is coupled to the slide maintaining members for causing their rotation. In a first embodiment of the invention one of the spaced members has a circular cross-section and is formed with four uniformly spaced detents in the outer surface thereof. The drive motor switch is a pantograph, one leg joint of which is positioned to cooperate with the detents.