Abstract: There is provided a core pin for injection molding of a ferrule accompanied by a small amount of wear by forming a core pin constituted by a circular cylinder portion having a first diameter at a portion thereof for forming one end face of the ferrule and having a first angle of inclination by which a diameter thereof is enlarged toward other end thereof, a circular cone portion having a second diameter larger than the first diameter at a portion thereof for forming other end of the ferrule and having a second angle of inclination an angle of which is larger than the first angle of inclination by which a diameter thereof is reduced toward the one end face and a curved face in contact with the circular cylinder portion and the circular cone portion and having a section in a circular arc shape.

Abstract: In the recording apparatus of this invention, liquid crystal light shutter operates by using the double frequency drive. The double frequency drive utilizes signals of a high frequency f.sub.H and lower frequency f.sub.L. The dielectric anisotropy of liquid crystal matrial becomes positive in the case of the frequency f.sub.L lower than crossover frequency f.sub.C and becomes negative in the case of the frequency f.sub.H higher than the frequency f.sub.C. When the data signal including the signal of the frequency f.sub.L for a final period of a writing cycle Tw, is applied to write selection electrodes and data signal electrodes, liquid crystal light shutter is kept open for the final period of the writing cycle Tw, namely, opening or closing state of the shutter which is caused during a selection period can be eliminated.

Abstract: In a recording apparatus of this invention, liquid crystal light shutter operates by using the double frequency drive. The double frequency drive employs a higher frequency f.sub.H and lower frequency f.sub.L. The dielectric anisotropy becomes positive in the case of the lower frequency f.sub.L than crossover frequency f.sub.C and becomes negative in the case of the higher frequency f.sub.H than the frequency f.sub.C of liquid crystal material. The driver circuit of liquid crystal light shutter includes a delay circuit (146). Both a recording data delayed through the delay circuit (146) and a recording data formed without going through the delayed circuit (146) are produced in an LSI, to be supplied to write selecting electrodes and signal electrodes of the liquid crystal light shutter, thereby driving the liquid crystal light shutter in a time sharing manner.