Recording apparatus with laser beam

An apparatus for recording by use of a laser, comprising:

• semiconductor laser element means for generating a laser beam the wavelength of which varies in accordance with variation of temperature to which said laser element means is exposed;
• photosensitive means positioned to be exposed to and sensitive to the laser beam generated by said semiconductor laser element means, said photosensitive means having a wavelength dependency such that the photosensitivity characteristics thereof vary in accordance with the variation of the wavelength of the laser beam within a range of wavelength variation;
• and
• filter means disposed in the path of the laser beam between said semiconductor laser element means and said photosensitive means, said filter means having laser beam transmission characteristics substantially opposite to the wavelength dependency of said photosensitive means.

An apparatus for recording by use of a laser comprising:

• semiconductor laser element means for generating a laser beam the wavelength of which varies in accordance with variation of temperature to which said laser element means is exposed;
• photosensitive means positioned to be exposed to the laser beam generated by said semiconductor laser element means and characterized in that its photosensitivity is reduced as the wavelength of the laser beam increases within a range of wavelength variation;
• and
• optical filter means disposed in the path of the laser beam between said semiconductor laser element means and said photosensitive means and having such characteristics that the quantity of laser beam transmitted therethrough increases as the wavelength of the laser beam increases within the range of wavelength variation.

An apparatus for recording by use of a laser comprising:

• semiconductor laser element means for generating a laser beam the wavelength of which varies in accordance with variation of temperature to which said laser element means is exposed;
• photosensitive means positioned to be exposed to the laser beam generated by said semiconductor laser element means and having sensitivity characteristics equal to A (.lambda.) for the wavelength of the laser beam within a range of wavelength variation;
• and
• filter means disposed in the path of the laser beam between said semiconductor laser element means and said photosensitive means and having a transmission factor equal to (constant/A(.lambda.)) for the wavelength of the laser beam.

An apparatus for recording by use of a laser comprising:

• means for generating a laser beam the wavelength of which varies;
• casing means for encasing said laser beam generating means, and having an opening through which the laser beam projects;
• photosensitive means positioned to be exposed to the laser beam generated by said laser beam generating means encased in said casing means, said photosensitive means having photosensitive characteristics dependent on the wavelength of a laser beam incident thereon;
• and
• filter means disposed adjacent the opening in said casing means, said filter means having laser beam transmission characteristics such that the variation of the wavelength of the laser beam to which said photosensitive means is exposed causes the sensitivity of said photosensitive means to be reduced.