Light beam recorder with an afocal anamorphic optical amplifier

Claim 2

A recording apparatus for recording information with a light beam, comprising: a beam source for emitting said light beam; light deflecting means for deflecting said light beam from said beam source in the direction of main scan by sine wave oscillation; an afocal anamorphic optical system for amplifying, in the direction of the main scan, the deflection angle of said light beam deflected by said deflecting means; and a scanning lens through which said light beam from said afocal anamorphic optical system is focused on a recording material.

Claim 3

A recording apparatus according to claim 1, wherein said anamorphic optical system has distortion characteristics which compensate for distortion of an image formed on said recording material in the direction of the main scan.

Claim 4

A recording apparatus according to claim 1, wherein at least one of said afocal anamorphic optical system and said scanning lens has an arcsine or an approximately arcsine distortion characteristic.

Claim 5

A recording apparatus for recording information with a light beam, comprising: a beam source for emitting said light beam; light deflecting means for deflecting said light beam from said beam source in the direction of main scan by sine wave oscillation; an afocal anamorphic optical system for amplifying, in the direction of the main scan, the deflection angle of said light beam deflected by said deflecting means, wherein said afocal anamorphic optical system has an arcsine or an approximately arcsine distortion characteristic, and wherein said scanning lens has an image forming characteristic represented by s=f×tan θ or approximately s=f×tan θ, where s represents the distance of the focal point from the optical axis, f represents the focal distance and θ represents the angle of incidence of the light beam with respect to the optical axis; and a scanning lens through which said light beam from said afocal anamorphic optical system is focused on a recording material.

Claim 6

A recording apparatus for recording information with a light beam, comprising: a beam source for emitting said light beam; light deflecting means for deflecting said light beam from said beam source in the direction of main scan by sine wave oscillation; an afocal anamorphic optical system for amplifying, in the direction of the main scan, the deflection angle of said light beam deflected by said deflecting means, wherein said afocal anamorphic optical system has an arcsine or an approximately arcsine distortion characteristic, and wherein said scanning lens has an image forming characteristic represented by s=f×tan θ or approximately s=f×tan θ, where s represents the distance of the focal point from the optical axis, f represents the focal distance and θ represents the angle of incidence of the light beam with respect to the optical axis; and a scanning lens through which said light beam from said afocal anamorphic optical system is focused on a recording material.

Claim 7

A recording apparatus according to claim 1, wherein said afocal anamorphic optical system does not have distortion characteristic while said scanning lens is an arcsine lens or a lens having a characteristic approximating the arcsine characteristic.

Claim 8

A recording apparatus according to claim 1, wherein said afocal anamorphic optical system is composed of a plurality of prisms.

Claim 9

A recording apparatus according to claim 1, wherein said afocal anamorphic optical system is composed of an even number of prisms.

Claim 10

A recording apparatus according to claim 1, wherein said afocal anamorphic optical system is composed of an even number of prisms and the prisms are arranged such that half of said prisms and the other half thereof are different in direction where the apex angles of the prisms face from each other with respect to the optical axis.

Claim 11

A recording apparatus for recording information with a light beam, comprising: a beam source for emitting said light beam; light deflecting means for deflecting said light beam from said beam source in the direction of main scan by sine wave oscillation; an afocal anamorphic optical system for amplifying, in the direction of the main scan, the deflection angle of said light beam deflected by said deflecting means, wherein said afocal anamorphic optical system is composed of an even number of prisms, the prisms are arranged such that half of said prisms the other half thereof are different in direction where the apex angles of the prisms face from each other with respect to the optical axis and the light beam incident to the incidence surface of said first prism at a right angle impinges upon the incidence surface of each of the remaining prisms at a right angle, respectively; and a scanning lens through which said light beam from said afocal anamorphic optical system is focused on a recording material.

Claim 12

A recording apparatus for recording information with a light beam, comprising: a beam source for emitting said light beam; light deflecting means for deflecting said light beam from said beam source in the direction of main scan by sine wave oscillation; an afocal anamorphic optical system for amplifying, in the direction of the main scan, the deflection angle of said light beam deflected by said deflecting means, wherein said afocal anamorphic optical system is composed of an even number of prisms, the prisms are arranged such that half of said prisms the other half thereof are different in direction where the apex angles of the prisms face from each other with respect to the optical axis and the light beam incident to the incidence surface of said first prism at a right angle impinges upon the incidence surface of each of the remaining prisms at a right angle, respectively; and a scanning lens through which said light beam from said afocal anamorphic optical system is focused on a recording material.

Claim 13

A recording apparatus according to claim 1, further comprising sub-scan means for effecting sub-scan of said recording material with said light beam.

Claim 14

A recording apparatus according to claim 1, wherein said afocal anamorphic optical system comprises a first prism, a second prism, a third prism and a fourth prism and wherein said first, second, third and fourth prisms are arranged such that the light beam incident to the incidence surface of said first prism at a right angle impinges upon the incidence surfaces of said second, third and fourth prisms at a right angle, respectively.

Claim 15

A recording apparatus according to claim 1, wherein said afocal anamorphic optical system includes a pair of cylindrical lenses which are spaced apart from each other by a predetermined distance.

Claim 16

A recording apparatus for recording information with a light beam, comprising: a semiconductor laser for emitting laser beam; a resonant scanner for deflecting said laser beam from said semiconductor laser in the direction of main scan by sine wave oscillation; an afocal anamorphic optical system for amplifying, in the direction of the main scan, the deflection angle of said laser beam deflected by said resonant scanner; and a scanning lens through which said laser beam from said afocal anamorphic optical system is focused on a recording material.

Claim 17

A recording apparatus for recording information with a light beam, comprising: a semiconductor laser for emitting laser beam; a resonant scanner for deflecting said laser beam from said semiconductor laser in the direction of main scan by sine wave oscillation; an afocal anamorphic optical system for amplifying, in the direction of the main scan, the deflection angle of said laser beam deflected by said resonant scanner; and a scanning lens through which said laser beam from said afocal anamorphic optical system is focused on a recording material.

Claim 18

A recording apparatus according to claim 13, further comprising a collimator disposed between said semiconductor laser and said resonant scanner.

Claim 19

A recording apparatus according to claim 13, wherein said afocal anamorphic optical system is composed of a plurality of prisms.

Claim 20

A recording apparatus according to claim 13, wherein said afocal anamorphic optical system comprises a first prism, a second prism, a third prism, and a fourth prism and wherein said first, second, third and fourth prisms are arranged such that the light beam incident to the incidence surface of said first prism at a right angle impinges upon the incidence surfaces of said second, third and fourth prisms at a right angle, respectively.

Claim 21

A recording apparatus according to claim 13 further comprising: photoelectric conversion means disposed between said scanning lens and said recording material at a position which is outside the path of the laser beam corresponding to the point of start of said main scan and capable of detecting passage of said laser beam; synchronizing signal generating means capable of generating a synchronizing signal composed of a pulse strain of a predetermined length after the passage of said laser beam is detected by said photoelectric conversion means; conversion means for converting the information to be recorded into a dot signal in accordance with said synchronizing signal; control means for effecting the sine wave oscillation of said resonant scanner and conducting on-off control of the semiconductor laser in accordance with said dot signal; and feeding means for feeding said recording material in the direction of sub-scan,

Claim 22

A recording apparatus according to claim 13, wherein said afocal anamorphic optical system is composed of a pair of cylindrical lenses which are spaced apart from each other by a predetermined distance.