Light source, light source device, laser image forming device and integrated circuit

Abstract

The light sources according to the present invention include a laser oscillator including a semiconductor laser, a drive circuit for the semiconductor laser, an ACC circuit, an APC circuit, and a switch, and a starting drive current storage device, and is controlled in such a manner that the driving current at the start of the laser driving be always constant, and after the start of the lighting, it is switched to the APC operation to carry out the power control of the laser light output.

1 . A light source device comprising:
 more than two light sources each comprising a laser oscillator and a starting drive current storage device for storing a starting drive current value for the laser oscillator, said laser oscillators having different wavelengths, respectively;   a power balancing storage device for storing the output ratio value between the lights from the more than two light sources having different wavelengths; and   photo detectors for detecting the optical powers of the more than two light sources having different wavelengths, respectively; and   said light source device performing a constant light output control in such a manner that the more than two light sources having different wavelengths initiate light emissions with the starting drive currents, respectively, the light outputs from the respective light sources are detected by the photo detector, and the driving currents of the respective light sources are varied so that the ratio between the outputs from the respective light sources becomes equal to the output ratio value that is stored in the power balancing storage device, thereby the more than two light sources having different wavelengths being controlled under a constant output control.   
     
     
         2 . A light source device comprising:
 more than two light sources each comprising a laser oscillator and a starting drive current storage device for storing a starting drive current value for the laser oscillator, said laser oscillators having different wavelengths, respectively;   a power balancing storage device for storing the output ratio value between the respective lights from the more than two light sources having different wavelengths;   photo detectors for detecting the optical powers of the more than two light sources having different wavelengths, respectively; and   said light source device performing a constant light output control in such a manner that the more than two light sources having different wavelengths initiate light emissions with the starting drive currents, respectively, the light outputs from the respective light sources are detected by the photo detector, the drive currents of the respective light sources are varied so that the ratio between the outputs from the respective light sources becomes equal to the output ratio value that is stored in the power balancing storage device, and after the output ratio is reached, one among the more than two light sources having different wavelengths is controlled under a constant current control, while the other remaining light sources are controlled under constant output control.   
     
     
         3 . A light source device as defined in  claim 2 , wherein
 the light source performing the constant current control is a light source having the largest reduction ratio with relative to the above-mentioned output ratio.   
     
     
         4 . A light source device as defined in  claim 3 , wherein
 the light source other than the light source having the largest reduction ratio among the more than two light sources is controlled to be driven while maintaining the above-mentioned output ratio, with following the output power of the light source having the largest reduction ratio.   
     
     
         5 . A light source device comprising:
 more than two light sources having different frequencies, and a power balancing storage device for storing the output ratio between the lights outputted from the more than two light sources having different wavelengths;   a first light source among the more than two light sources having different wavelengths comprising a laser oscillator and a starting drive current storage device for storing the starting drive current for the laser oscillator, and being operated to start light emission with a starting drive current which is stored in the starting drive current storage device and then to perform a constant light output control; and   light sources other than the first light source being controlled under constant light output control while maintaining the above-described output ratio, with following the output power of the first light source.   
     
     
         6 . A light source device comprising:
 more than two light sources having different wavelengths;   a first light source among the more than two light sources having different wavelengths performing a constant current control; and   light sources other than the first light source carrying out constant light output control based on the light output from the first light source after the light emission by the first light source is performed.   
     
     
         7 . A light source device as defined in  claim 6 , wherein
 a power balancing storage device for storing the output ratio between the light outputs from the more than two light sources having different wavelengths is provided, the light source having the largest light output reduction rate among the more than two light sources having different wavelengths is made as the first light source, and the light sources other than the first light source are controlled to be driven while keeping the above-described output ratio with following the output power of said first light source.   
     
     
         8 . An integrated circuit for driving and controlling light sources, wherein
 said light source is initiated with a light emission with a predetermined starting drive current, and after the light emission, a constant light output control is carried out.   
     
     
         9 . An integrated circuit for driving and controlling more than two light sources having different wavelengths, wherein
 light emissions by the light sources are initiated with predetermined starting drive currents,   light outputs of the respective light sources are detected after the light emissions are started,   driving current values of the respective light sources are varied so that the detected light outputs of the respective light sources have a predetermined output ratio between them, thereby carrying out constant light output controls for the respective more than two light sources.   
     
     
         10 . An integrated circuit for driving and controlling more than two light sources having different wavelengths, wherein
 light emissions by the light sources are initiated with predetermined starting drive currents,   light outputs of the respective light sources are detected after the light emissions are started,   the driving current values of the respective light sources are varied so that the detected light outputs of the respective light sources have a predetermined output ratio between them, thereby carrying out constant light output controls for the respective more than two light sources.   
     
     
         11 . An integrated circuit for driving and controlling more than two light sources having different wavelengths, wherein
 a first light source among the more than two light sources is controlled under a constant current control, and the light sources other than the first light source are controlled on the basis of the light outputs of the first light source after the light emission by the first light source is occurred.