| 摘要 |
PURPOSE:To increase the kinds of the data that can be handled by incorporating n-ways of optical conditions at the recording and reproducing. CONSTITUTION:Single wavelength light sources 111, 113 of wavelengths lambda1, lambda3 are opposed to a recording medium 12 by way of a half mirror 13. The single wavelength light of the wavelengths lambda1, lambda3 having transmitted through the half mirror 13 is made reference light. The single wavelength light of the wavelengths lambda1, lambda3 having been reflected by the half mirror 13 is passed through a total reflecting mirror 14 and an original information recording medium 15 to be made to object light. Both lights are so radiated onto the recording medium 12 that the angles assumed by them become theta1, theta3, whereby two kinds of holograms are made. The single wavelength lights of the single wavelength light sources 312, 314 of lambda2, lambda4 in wavelength which are so disposed that their optical axes assume a right angle are directed toward a photo sensor group 32 through a half mirror 33, whereby the holograms on the recording media 21, 22 on a data card 20 are reproduced. Thereby, two kinds of holograms are made and are taken out and reproduced by kinds. |
