Image Number 11 for United States Patent #5883873.
An optical recording and reproducing device of the present invention has an objective lens designed so as to form a light spot with a set diameter on a DVD, while to form, on a CD, a light spot with a set diameter different from the above diameter. Respective working distances WD1 and WD2 with respect to the DVD and the CD are set in accordance with deflection standards F for the DVD and the CD, respectively. By doing so, as compared with conventional cases where the deflection standards F are not taken into consideration, the working distance WD1 is decreased. As a result, the device is thinned, compared with the conventional cases.