An optical type information recording medium has guide grooves for tracking formed in a concentric or spiral shape at a predetermined pitch; and a pre-format pit formed approximately midway between the guide grooves in the normal direction thereof and recording at least address information. The optical type information recording medium is constructed such that the predetermined pitch is a value ranged from 1.4 .mu.m to 2.0 .mu.m, and the depth of the pre-format pit is a value ranged from 0.46 .lambda./n to 0.58 .lambda./n where n shows the refractive index of a substrate of the medium and .lambda. shows a wavelength of a light source for reading the information recorded to the medium, and the cross-sectional shape of the pre-format pit in the normal direction is provided in a range represented by a first predetermined inequality using a function of the second degree, and the cross-sectional shape of the guide grooves in the normal direction is provided in a range represented by a second predetermined inequality using a function of the second degree.

An optical recording element comprising a recording medium which includes an information recording area formed at every unit in a non-continuous condition, the recording medium further including sample pits disposed at intervals of a fixed distance for providing basic information about the locations of the recording units in same track. Each sample pit comprises a plurality of pits disposed next to the sequence of the recording units so that the spacing between the pits differs from the spacing between the recording units. At least one of the plurality of pits is a long-sized inclined pit which is inclined at an angle in the range of 6.degree. to 80.degree. to a recording track. A driving system for driving the optical recording element for recording information in the non-continuous recording area or erasing information stored therein with a light beam the output of which is varied as required and checking whether said recording or erasing has been correctly performed, within a very short time in which the light beam passes through the non-continuous recording area. By using the optical recording element in combination with its driving system, the processing speed for reducing, erasing and verifying these functions can be greatly improved and the irradiating position of the light beam at every recording unit can be correctly controlled.

A magneto-optical disc includes a pit forming region and a groove forming region on a surface of a substrate and a recording layer covering the pit and groove forming regions. The pit forming region includes a row of pits having a width of 0.40-0.55 .mu.m and a depth of 600-900 .ANG. and the groove forming region includes a spiral groove having a width of 0.95-1.15 .mu.m and a depth of 600-900 .ANG.. The disc is recorded and read by using an optical head with an objective lens having a numerical aperture of 0.40 to 0.50 and directing linearly polarized laser light having a wavelength of 600 to 900 nm to the disc such that its electric field vector has a direction perpendicular to the groove and the pit row. Tracking, seeking and information retrieval can be done with minimal errors using the same laser light beam in both the pit and groove forming regions.

An optical recording element comprising a recording medium which includes an information recording area formed at every unit in a non-continuous condition, the recording medium further including sample pits disposed at intervals of a fixed distance for providing basic information about the locations of recording units in the same track. Each sample pit comprises a plurality of pits disposed next to the sequence of the recording units so that the spacing between the pits differs from the spacing between the recording units. At least one of the plurality of pits is a long-sized inclined pit which is inclined at an angle in the range of 6.degree. to 80.degree. to a recording track. A driving system for driving the optical recording element for recording information in the non-continuous recording area or erasing information stored therein with a light beam the output of which is varied as required and checking whether said recording or erasing has been correctly performed, within a very short time in which the light beam passes through the non-continuous recording area. By using the optical recording element in combination with its driving system, the processing speed for reducing, erasing and verifying these functions can be greatly improved and the irradiating position of the light beam at every recording unit can be correctly controlled.

An optical recording medium is made up of an optically transparent substrate having a groove and a land which have approximately the same width and are formed spirally or concentrically, where the groove has an optical depth described by (1/8+(1/2)n).lambda., n is 0 or a positive integer and .lambda. is a wavelength of a laser. At least one of two walls defining the groove is zigzag shaped and the groove is capable of having digital information recorded thereon.