Apparatus and system for spot position control in an optical output device employing a variable wavelength light source

Claim 2

In an optical output device wherein a beam of light is generated and focused to a spot upon an image plane means, an apparatus for controlling the position of the spot in the slow scan plane of the image plane means, comprising: a light source capable of emitting the beam of light at a selected one of at least two selectable wavelengths; and beam deflecting means for deflecting the beam of light an amount which depends on the wavelength of the beam of light, the amount of deflection determining the position of the spot in the slow scan plane on the image plane means.

Claim 3

The apparatus of claim 1, wherein the light source is a variable wavelength laser.

Claim 4

The apparatus of claim 1, wherein the beam deflecting means is a prism.

Claim 5

The apparatus of claim 3, wherein the prism is composed of glass.

Claim 6

The apparatus of claim 3, wherein the prism is composed, at least in part, of a crystalline material.

Claim 7

The apparatus of claim 5, wherein the crystalline material is AlGaAs.

Claim 8

The apparatus of claim 5, further including means to vary a bias applied to the crystalline portion of the prism such that a selected change in bias applied to the semiconducting portion of the prism results in a selected change in the refractive index of, and hence the amount the beam is deflected by, the prism.

Claim 9

The apparatus of claim 1, wherein the beam deflecting means is a diffraction grating.

Claim 10

In an optical output device capable of simultaneously emitting a plurality of light beams which are focused to individual spots upon an image plane means, an apparatus for controlling the position of the spots in the slow scan plane of the image plane means, comprising: a light source capable of emitting the beams of light at a selected one of at least two selectable wavelengths; and beam deflecting means for deflecting the beam of light an amount which depends on the wavelength of the beam of light, the amount of deflection determining the position of the spot in the slow scan plane on the image plane means.

Claim 11

In an optical output device capable of simultaneously emitting a plurality of light beams which are focused to individual spots upon an image plane means, an apparatus for controlling the position of the spots in the slow scan plane of the image plane means, comprising: a light source capable of emitting the beams of light at a selected one of at least two selectable wavelengths; and beam deflecting means for deflecting the beam of light an amount which depends on the wavelength of the beam of light, the amount of deflection determining the position of the spot in the slow scan plane on the image plane means.

Claim 12

The apparatus of claim 9, wherein the light source is variable wavelength laser.

Claim 13

The apparatus of claim 10, wherein the beam deflecting means is a prism.

Claim 14

The apparatus of claim 11, wherein the prism is composed of glass.

Claim 15

The apparatus of claim 11, wherein the prism is composed, at least in part, of a semiconducting material.

Claim 16

The apparatus of claim 13, wherein the semiconductor material is AlGaAs.

Claim 17

The apparatus of claim 13, further including means to vary a bias applied to the semiconducting portion of the prism such that a selected change in bias applied to the semiconducting portion of the prism results in a selected change in the refractive index of, and hence the amount the beam is deflected by, the prism.

Claim 18

The apparatus of claim 10, wherein the beam deflecting means is a diffraction grating.

Claim 19

In an optical output device capable of simultaneously emitting a plurality of light beams which are focused to individual spots upon an image plane means, an apparatus for independently controlling the position of each spot in the slow scan plane of the image plane means, comprising: a light source capable of emitting each beam of light at an individually selected one of at least two selectable wavelengths; and beam deflecting means for deflecting each beam of light an amount which depends on the wavelength of the beam of light, the amount of deflection determining the position of the spot in the slow scan plane on the image plane means.

Claim 20

In an optical output device capable of simultaneously emitting a plurality of light beams which are focused to individual spots upon an image plane means, an apparatus for independently controlling the position of each spot in the slow scan plane of the image plane means, comprising: a light source capable of emitting each beam of light at an individually selected one of at least two selectable wavelengths; and beam deflecting means for deflecting each beam of light an amount which depends on the wavelength of the beam of light, the amount of deflection determining the position of the spot in the slow scan plane on the image plane means.

Claim 21

The apparatus of claim 17, wherein the light source is a variable wavelength laser.

Claim 22

The apparatus of claim 17, wherein the beam deflecting means is a prism.

Claim 23

The apparatus of claim 19, wherein the prism is composed of glass.

Claim 24

The apparatus of claim 19, wherein the prism is composed, at least in part, of a semiconducting material.

Claim 25

The apparatus of claim 21, wherein the semiconductor material is AlGaAs.

Claim 26

The apparatus of claim 22, further including means to vary a bias applied to the semiconducting portion of the prism such that a selected change in bias applied to the semiconducting portion of the prism results in a selected change in the refractive index of, and hence the amount the beam is deflected by, the prism.

Claim 27

The apparatus of claim 18, wherein the beam deflecting means is a diffraction grating.

Claim 30

The system of claim 25, further including means for scanning the light beam in a raster fashion in a fast scan plane, and further wherein said beam deflecting means is oriented such that a shifting of the light beam from one to another of the at least two selectable wavelengths causes the beam deflecting means to change the amount that the beam is deflected and thereby reposition the spot on the image plane means in a slow scan direction which is orthogonal to the fast scan direction.

Claim 31

The system is claim 25, wherein the light source comprises a variable wavelength laser, and further wherein the system includes means for selecting one of at least two selectable wavelengths of the output of the laser.

Claim 32

The system of claim 27, wherein the the beam deflecting means is a prism.

Claim 33

The system of claim 28, wherein the prism is composed of glass.

Claim 34

The system of claim 28, wherein the prism is composed, at least in part, of a semiconducting material.

Claim 35

The system of claim 30, wherein the semiconductor material is AlGaAs.

Claim 36

The apparatus of claim 30, further including means to vary a bias applied to the semiconducting portion of the prism such that a selected change in bias applied to the semiconducting portion of the prism results in a selected change in the refractive index of, and hence the amount the beam is deflected by, the prism.

Claim 37

The system of claim 27, wherein the beam deflecting means is a diffraction grating.

Claim 38

The system of claim 27, further including means for determining the existence and extent of any error in the position of the spot in the slow scan plane, and means for application of such determination to the means for controlling the wavelength of the output of the laser, such that an appropriate shift of the light beam from one to another of the at least two selectable wavelengths is caused, and further that such a shift in wavelength causes the beam deflecting means to change the amount that the beam is deflected and thereby reposition the spot on the image plane means in the slow scan direction to compensate for the determined existence and extent of error.

Claim 39

The system of claim 34, further including means for determining the need for, and the extent of, the application of predetermined spot position correction, and means for application of such determination to the means for controlling the wavelength of the output of the laser, such that an appropriate shift of the light beam from one to another of the at least two selectable wavelengths is caused, and further that such a shift in wavelength causes the beam deflecting means to change the amount that the beam is deflected and thereby reposition the spot on the image plane means in the slow scan direction in accordance with the predetermined correction.

Claim 40

The system of claim 27, further including means located in the path of said light beam for modulating the light beam in accordance with a data signal applied to said means for modulating.

Claim 43

An improved printing apparatus, the improvement comprising: a variable wavelength laser light source capable of emitting a beam of laser light at a selected one of at least two selectable wavelengths; means for selecting the one of at least two selectable wavelengths of the output of the laser light source; rotating output scanning means located in the path of said light beam for scanning the light beam in a raster fashion in a fast scan plane; a beam deflecting element located in the path of said light beam whose index of refraction varies as a function of the wavelength of light passing therethrough, for deflecting the beam of light in a slow scan plane, which is orthogonal to the fast scan plane, an amount which depends on the wavelength of the beam of light; a photoreceptive element for receiving the light beam; means for focusing the light beam to a spot on the photoreceptive element; means for determining the existence and extent of any error in the position of the spot on the photoreceptive element; means for determining the need for, and extent of, the application of predetermined spot position correction; and means for application of such determinations of the existence and extent of any error and the need for, and extent of, the application of predetermined spot position correction to the means for selecting the wavelength of the output of the laser such that an appropriate shift of the light beam from one to another of the at least two selectable wavelengths is caused, and further that such a shift in wavelength causes the beam deflecting element to change the amount that the beam is deflected and thereby reposition the spot on the photoreceptive element in the slow scan direction to compensate for the determined existence and extent of error and the determined needed and extent of the application of predetermined spot position correction.

Claim 44

An improved printing apparatus, the improvement comprising: a variable wavelength laser light source capable of emitting a beam of laser light at a selected one of at least two selectable wavelengths; means for selecting the one of at least two selectable wavelengths of the output of the laser light source; rotating output scanning means located in the path of said light beam for scanning the light beam in a raster fashion in a fast scan plane; a beam deflecting element located in the path of said light beam whose index of refraction varies as a function of the wavelength of light passing therethrough, for deflecting the beam of light in a slow scan plane, which is orthogonal to the fast scan plane, an amount which depends on the wavelength of the beam of light; a photoreceptive element for receiving the light beam; means for focusing the light beam to a spot on the photoreceptive element; means for determining the existence and extent of any error in the position of the spot on the photoreceptive element; means for determining the need for, and extent of, the application of predetermined spot position correction; and means for application of such determinations of the existence and extent of any error and the need for, and extent of, the application of predetermined spot position correction to the means for selecting the wavelength of the output of the laser such that an appropriate shift of the light beam from one to another of the at least two selectable wavelengths is caused, and further that such a shift in wavelength causes the beam deflecting element to change the amount that the beam is deflected and thereby reposition the spot on the photoreceptive element in the slow scan direction to compensate for the determined existence and extent of error and the determined needed and extent of the application of predetermined spot position correction.