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US 4,375,067 AGranted
Semiconductor laser device having a stabilized output beam
AssigneeCanon Kabushiki Kaisha
InventorTakashi Kitamura
Life of this patent
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Abstract
A semiconductor laser device in which a thermosensitive element exhibiting a resistance variation with temperature is installed at a location more faithfully transmitting the temperature of a semiconductor laser element and the thermosensitive element is connected to a circuit for taking out the output from a photodetector receiving the light from the laser element so that, when a wavelength fluctuation is caused by a temperature variation, information is fed back so that a required quantity of light corresponding to that wavelength is obtained, whereby an optimal quantity of light may always be maintained, and an image recording apparatus using the same.
Claims32
A semiconductor laser device having a stabilized output beam, comprising:
- a semiconductor laser element for emitting a front beam and a rear beam in a direction different from that of said front beam;
- and
- a light-receiving element for directly detecting the intensity of the rear beam from said laser element, said light-receiving element being disposed in opposition to the surface of said semiconductor laser element from which the rear beam is emitted and being inclined relative to the rear beam so as to be non-perpendicular thereto and so as not to mix the rear beam reflected from the light-receiving surface of said light-receiving element with the front beam.
A semiconductor laser device having a stabilized output beam, comprising:
- a semiconductor laser element;
- driving means for driving said semiconductor laser element;
- a light-receiving element for detecting the intensity of the output beam of said laser element;
- a temperature detecting element for detecting temperature provided near said laser element;
- and
- control means for controlling said driving means in accordance with the output of said temperature detecting element and the output of said light-receiving element and for thereby controlling the light quantity of the output beam of said laser element to vary in accordance with wavelength shift of the output beam caused by temperature variation.
3 more elements
An image recording apparatus comprising:
- a semiconductor laser element;
- a photosensitive medium receiving the output light of said laser element;
- means for forming an electrostatic latent image on said photosensitive medium in response to said output light;
- and
- compensation means for compensating for a variation in sensitivity of said photosensitive medium caused by an output wavelength shift based on a temperature variation of said laser element.
2 more elements
An image recording apparatus comprising:
- a photosensitive medium;
- charging means for uniformly charging said photosensitive medium;
- a semiconductor laser element;
- modulating means for giving strength and weakness to the output beam of said semiconductor laser element;
- deflector means for deflecting said output beam to form a latent image on said photosensitive medium by discharging said photosensitive medium by the modulated beam modulated by said modulating means;
- first detector means for detecting the intensity of said output beam;
- means for controlling the driving current of said laser element in accordance with the detection output of said first detector means;
- and
- compensation means for compensating for a variation in sensitivity of said photosensitive medium caused by the shift of the output wavelength of said laser element resulting from a temperature variation, said compensation means comprising second detector means for detecting the temperature of said semiconductor laser element and means for varying the driving current of said laser element in accordance with the output of said second detector means.
6 more elements
An image recording apparatus comprising:
- a semiconductor laser element;
- a photosensitive medium receiving the output light of said laser element;
- means for forming an electrostatic latent image on said photosensitive medium in response to said output light;
- detector means for detecting the intensity of said output light;
- an optical filter for compensating for a variation in sensitivity of said photosensitive medium caused by an output wavelength shift based on a temperature variation of said laser element, said optical filter having a transmission factor distribution corresponding to the spectrum sensitivity distribution of said photosensitive medium;
- and
- an adjusting mechanism capable of arbitrarily adjusting an angle of said optical filter with respect to the direction of emergence of said output light from said laser element.
4 more elements
An image recording apparatus comprising:
- a photosensitive medium;
- charging means for uniformly charging said photosensitive medium;
- a semiconductor laser element;
- modulating means for giving strength and weakness to the output beam of said semiconductor laser element;
- deflector means for deflecting said modulated output beam to form a latent image on said photosensitive medium by discharging said photosensitive medium in accordance with the modulated beam modulated by said modulating means;
- detector means for detecting the intensity of said output beam;
- means for controlling the driving current of said laser element in accordance with the detection output of said detector means;
- and
- compensation means for compensating for a variation in sensitivity of said photosensitive medium caused by the shift of the output wavelength of said laser element resulting from a temperature variation, said compensation means comprising an optical filter having a transmission factor distribution corresponding to the spectrum sensitivity distribution of said photosensitive medium.
6 more elements
Dependencies are inferred from the claim text.