Optical-element holding device, method of adjusting shape of optical element, optical-element shape adjusting device, method of correcting scanning line variation, optical scanning device, and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorsTaku Amada, Tomohiro Nakajima, Akihisa Itabashi
Life of this patent
Estimating the term…
Abstract
An optical-element holding device includes an elastic member that presses an optical element with an elastic force in a direction orthogonal to an optical axis of the optical element and orthogonal to a longitudinal direction of the optical element, and a support member that forms a pair with the elastic member and supports the optical element against a pressing force of the elastic member. At least three pairs of the elastic member and the support member are provided.
Claims97
An optical-element holding device comprising:
- an elastic member that presses an optical element with an elastic force in a direction orthogonal to an optical axis of the optical element and orthogonal to a longitudinal direction of the optical element;
- and
- a support member that forms a pair with the elastic member and supports the optical element against a pressing force of the elastic member, wherein
- at least three pairs of the elastic member and the support member are provided.
An optical-element holding device comprising:
- a holding member that is provided on at least one of one side and other side of an optical element, and includes two supporting portions that supports the optical element, the two supporting portions being separated with a distance L;
- an adjusting member that is provided in the holding member, and deforms the optical element with a pressing force;
- and
- an elastic member that is arranged in opposite to the adjusting member, to press and fix the optical element to the holding member, wherein
- both ends of the optical element and the holding member are rotatably supported by the two supporting portions, and
- when an elastic modulus Ki is defined as Ki=(Wi×L3)/(48×di), where a deflection of the optical element at a time of applying a load Wi to a center of the optical element and the holding member is di, the elastic modulus of the optical element K1 and the elastic modulus of the holding member K2 satisfies
- K2/K1≧0.5.
An optical scanning device comprising:
- a light deflector that deflects a light beam emitted from a light source;
- at least one optical element that focuses the deflected light beam on a surface to be scanned as a beam spot;
- and
- an optical-element holding unit including
- an elastic member that presses an optical element with an elastic force in a direction orthogonal to an optical axis of the optical element and orthogonal to a longitudinal direction of the optical element;
- and
- a support member that forms a pair with the elastic member and supports the optical element against a pressing force of the elastic member, wherein
- at least three pairs of the elastic member and the support member are provided.
An image forming apparatus comprising:
- an optical scanning unit that includes
- a light deflector that deflects a light beam emitted from a light source;
- at least one optical element that focuses the deflected light beam on a surface to be scanned as a beam spot;
- and
- an optical-element holding unit including
- an elastic member that presses an optical element with an elastic force in a direction orthogonal to an optical axis of the optical element and orthogonal to a longitudinal direction of the optical element;
- and
- a support member that forms a pair with the elastic member and supports the optical element against a pressing force of the elastic member, wherein
- at least three pairs of the elastic member and the support member are provided.
An image forming apparatus comprising:
- an optical scanning unit that includes
- a light deflector that deflects a light beam emitted from a light source;
- at least one optical element that focuses the deflected light beam on a surface to be scanned as a beam spot;
- and
- an optical-element holding unit including
- an elastic member that presses an optical element with an elastic force in a direction orthogonal to an optical axis of the optical element and orthogonal to a longitudinal direction of the optical element;
- a support member that forms a pair with the elastic member and supports the optical element against a pressing force of the elastic member, wherein at least three pairs of the elastic member and the support member are provided;
- and
- a detecting unit that detects an amount of deflection of the optical element, wherein
- the support member is capable of adjusting an amount of movement based on a result of detection by the detecting unit, and
- the detecting unit detects the amount of deflection of the optical element from a toner image formed on a transfer belt.
A method of adjusting shape of an optical element in an optical-element holding device that includes an elastic member that presses an optical element with an elastic force in a direction orthogonal to an optical axis of the optical element and orthogonal to a longitudinal direction of the optical element, and a support member that forms a pair with the elastic member and supports the optical element against a pressing force of the elastic member, wherein at least three pairs of the elastic member and the support member are provided, the method comprising:
- adjusting deflection of the optical element by adjusting a position of the support ember forming the pair with the elastic member.
A method of adjusting shape of an optical element in an optical-element holding device that includes a holding member that is provided on at least one of oneside and other side of an optical element, and includes two supporting portions that supports the optical element, the two supporting portions being separated with a distance L, an adjusting member that is provided in the holding member, and deforms the optical element with a pressing force, and an elastic member that is arranged in opposite to the adjusting member, to press and fix the optical element to the holding member, wherein both ends of the optical element and the holding member are rotatably supported by the two supporting portions, and when an elastic modulus Ki is defined as Ki=(Wi×L3)/(48×di), where a deflection of the optical element at a time of applying a load Wi to a center of the optical element and the holding member is di, the elastic modulus of the optical element K1 and the elastic modulus of the holding member K2 satisfies K2/K1≧0.5, the method comprising:
- adjusting deflection of the optical element by adjusting the optical element with the adjusting member.
A method of adjusting shape of an optical element, the method comprising:
- adjusting deflection of the optical element by applying an external force to the optical element, wherein
- the shape of the optical element after the adjusting is a shape with a number of peaks equal to or less than three by making the external force act to one place.
A mechanism for adjusting shape of an optical element, the mechanism comprising:
- an elastic member that presses an optical element with an elastic force in a direction orthogonal to an optical axis of the optical element and orthogonal to a longitudinal direction of the optical element;
- and
- a support member that forms a pair with the elastic member and supports the optical element against a pressing force of the elastic member, wherein
- at least three pairs of the elastic member and the support member are provided, and
- an external force is to one place of the optical element by the elastic members and the support members to adjust the shape of the optical element so that the shape of the optical element after adjustment becomes a shape with a number of peaks equal to or less than three.
A mechanism for adjusting shape a optical element to which a method of adjusting the shape of the optical element is applied, the method including applying a counteracting elastic force against each of adjustable external forces applied to the optical element in a preliminary assembly stage in an adjusting process and making the external force act to one place so that the shape of the optical element after the adjusting is a shape with a number of peaks equal to or less than three, the mechanism comprising:
- a first plate elastic member and a second plate elastic member that are longer than the optical element, arranged on both sides of the optical element in a direction perpendicular to a longitudinal direction, and nip the optical element;
- a plurality of press adjusting members that are arranged in a row on one of the first and the second plate elastic members in the longitudinal direction to press and deform the optical element, the press adjusting members including a first press adjusting member, a second press adjusting member, and a third press adjusting member;
- two support members that are arranged between other of the first and the second plate elastic members and the optical element in opposite to the first and the second press adjusting members, respectively;
- and
- a third elastic member that is arranged between the first and the second plate elastic members and applies an elastic force to the optical element in opposite to a pressing force by the third press adjusting member.
An optical scanning device comprising:
- a mechanism for adjusting shape an optical element to which a method of adjusting the shape of the optical element is applied, the method including adjusting deflection of the optical element by applying an external force to the optical element so that the shape of the optical element after the adjusting is a shape with a number of peaks equal to or less than three by making the external force act to one place, wherein
- the shape of the optical element is adjustable in a state in which the optical element is mounted on the optical scanning device.
An image forming apparatus comprising:
- an optical scanning unit that includes a mechanism for adjusting shape an optical element to which a method of adjusting the shape of the optical element is applied, the method including adjusting deflection of the optical element by applying an external force to the optical element so that the shape of the optical element after the adjusting is a shape with a number of peaks equal to or less than three by making the external force act to one place, wherein
- the shape of the optical element is adjustable in a state in which the optical element is mounted on the optical scanning unit.
An optical scanning device comprising:
- a first focusing optical system that collimates a light beam from a light source;
- a deflector that deflects the light beam from the first focusing optical system to a medium to be scanned;
- a second focusing optical system that is arranged between the first focusing optical system and the deflector, and forms a long line image in a deflection direction near a reflection surface of the deflector;
- a third focusing optical system that scans the medium at a constant speed using the deflected light beam from the deflector as a light spot, the third focusing optical system including a plurality of optical elements;
- and
- a pressing member that presses at least one of optical elements at a plurality of places in a direction orthogonal to the deflection direction to hold the optical element, and controls a position of the optical element, wherein
- the pressing members are made of different materials depending on a pressing place.
An optical scanning device comprising:
- a first focusing optical system that collimates a light beam from a light source;
- a deflector that deflects the light beam from the first focusing optical system to a medium to be scanned;
- a second focusing optical system that is arranged between the first focusing optical system and the deflector, and forms a long line image in a deflection direction near a reflection surface of the deflector;
- a third focusing optical system that scans the medium at a constant speed using the deflected light beam from the deflector as a light spot, the third focusing optical system including a plurality of optical elements;
- and
- a pressing member that presses at least one of optical elements at a plurality of places in a direction orthogonal to the deflection direction to hold the optical element, and controls a position of the optical element, wherein
- the pressing members have different thicknesses depending on a pressing place.
An optical scanning device comprising:
- a first focusing optical system that collimates a light beam from a light source;
- a deflector that deflects the light beam from the first focusing optical system to a medium to be scanned;
- a second focusing optical system that is arranged between the first focusing optical system and the deflector, and forms a long line image in a deflection direction near a reflection surface of the deflector;
- a third focusing optical system that scans the medium at a constant speed using the deflected light beam from the deflector as a light spot, the third focusing optical system including a plurality of optical elements;
- and
- a pressing member that presses at least one of optical elements at a plurality of places in a direction orthogonal to the deflection direction to hold the optical element, and controls a position of the optical element, wherein
- the pressing members have different contact areas with respect to the optical element depending on a pressing place.
An image forming apparatus comprising:
- an optical scanning unit that includes
- a first focusing optical system that collimates a light beam from a light source;
- a deflector that deflects the light beam from the first focusing optical system to a medium to be scanned;
- a second focusing optical system that is arranged between the first focusing optical system and the deflector, and forms a long line image in a deflection direction near a reflection surface of the deflector;
- a third focusing optical system that scans the medium at a constant speed using the deflected light beam from the deflector as a light spot, the third focusing optical system including a plurality of optical elements;
- and
- a pressing member that presses at least one of optical elements at a plurality of places in a direction orthogonal to the deflection direction to hold the optical element, and controls a position of the optical element, wherein
- the pressing members are made of different materials depending on a pressing place.
An image forming apparatus comprising:
- an optical scanning unit that includes
- a first focusing optical system that collimates a light beam from a light source;
- a deflector that deflects the light beam from the first focusing optical system to a medium to be scanned;
- a second focusing optical system that is arranged between the first focusing optical system and the deflector, and forms a long line image in a deflection direction near a reflection surface of the deflector;
- a third focusing optical system that scans the medium at a constant speed using the deflected light beam from the deflector as a light spot, the third focusing optical system including a plurality of optical elements;
- and
- a pressing member that presses at least one of optical elements at a plurality of places in a direction orthogonal to the deflection direction to hold the optical element, and controls a position of the optical element, wherein
- the pressing members have different thicknesses depending on a pressing place.
An image forming apparatus comprising:
- an optical scanning unit that includes
- a first focusing optical system that collimates a light beam from a light source;
- a deflector that deflects the light beam from the first focusing optical system to a medium to be scanned;
- a second focusing optical system that is arranged between the first focusing optical system and the deflector, and forms a long line image in a deflection direction near a reflection surface of the deflector;
- a third focusing optical system that scans the medium at a constant speed using the deflected light beam from the deflector as a light spot, the third focusing optical system including a plurality of optical elements;
- and
- a pressing member that presses at least one of optical elements at a plurality of places in a direction orthogonal to the deflection direction to hold the optical element, and controls a position of the optical element, wherein
- the pressing members have different contact areas with respect to the optical element depending on a pressing place.
An optical scanning device that scans a surface to be scanned with a light beam from a light source by a rotary polygon mirror and forms an image on the surface with a focusing optical system, the optical scanning device comprising:
- a scanning-line-variation correcting unit that corrects a variation of a scanning line on the surface, wherein
- the scanning-line-variation correcting unit generates a variation of the scanning line of a curve component of equal to or higher than a third-order function having peaks at a plurality of portions along a main scanning direction, and offsets the curve component by generating a variation of the scanning line of an opposite shape.
An optical scanning device that scans a surface to be scanned with a light beam from a light source by a rotary polygon mirror and forms an image on the surface with a focusing optical system, the optical scanning device comprising:
- a scanning-line-variation correcting unit that corrects a variation of a scanning line on the surface, the scanning-line-variation correcting unit including
- a first scanning-line-variation correcting unit that adjusts a first curve component of a quadratic function having a peak at one portion in a main scanning direction;
- and
- a second scanning-line-variation correcting unit that adjusts a second curve component of equal to or higher than a third-order function having peaks at a plurality of portions along a main scanning direction.
An optical scanning device that scans a surface to be scanned with a light beam from a light source by a rotary polygon mirror and forms an image on the surface with a focusing optical system the optical scanning device comprising:
- a focal-line varying unit that varies a focal line of an optical element having a convergent action at least in a sub-scanning direction from among optical elements constituting the focusing optical system, so that the focal line has peaks at a plurality of portions along a main scanning direction, wherein
- a variation of the focal line is corrected by the focal-line varying unit.
An image forming apparatus for obtaining a color image by forming electrostatic latent images on a plurality of image carriers, developing the electrostatic latent images with toners of different colors for each of the image carriers to form toner images, and sequentially transferring the toner images onto a sheet-type recording medium in a superposing manner, the image forming apparatus comprising:
- an optical scanning device that scans a surface to be scanned with a light beam from a light source by a rotary polygon mirror and forms an image on the surface with a focusing optical system, the optical scanning device including a scanning-line-variation correcting unit that corrects a variation of a scanning line on the surface, wherein
- the scanning-line-variation correcting unit generates a variation of the scanning line of a curve component of equal to or higher than a third-order function having peaks at a plurality of portions along a main scanning direction, and offsets the curve component by generating a variation of the scanning line of an opposite shape.
An image forming apparatus for obtaining a color image by forming electrostatic latent images on a plurality of image carriers, developing the electrostatic latent images with toners of different colors for each of the image carriers to form toner images, and sequentially transferring the toner images onto a sheet-type recording medium in a superposing manner, the image forming apparatus comprising:
- an optical scanning device that scans a surface to be scanned with a light beam from a light source by a rotary polygon mirror and forms an image on the surface with a focusing optical system, the optical scanning device including a scanning-line-variation correcting unit that corrects a variation of a scanning line on the surface, the scanning-line-variation correcting unit that includes
- a first scanning-line-variation correcting unit that adjusts a first curve component of a quadratic function having a peak at one portion in a main scanning direction;
- and
- a second scanning-line-variation correcting unit that adjusts a second curve component of equal to or higher than a third-order function having peaks at a plurality of portions along a main scanning direction.
An image forming apparatus for obtaining a color image by forming electrostatic latent images on a plurality of image carriers, developing the electrostatic latent images with toners of different colors for each of the image carriers to form toner images, and sequentially transferring the toner images onto a sheet-type recording medium in a superposing manner, the image forming apparatus comprising:
- an optical scanning device that scans a surface to be scanned with a light beam from a light source by a rotary polygon mirror and forms an image on the surface with a focusing optical system, the optical scanning device including a focal-line varying unit that varies a focal line of an optical element having a convergent action at least in a sub-scanning direction from among optical elements constituting the focusing optical system, so that the focal line has peaks at a plurality of portions along a main scanning direction, wherein
- a variation of the focal line is corrected by the focal-line varying unit.
An image forming apparatus for obtaining a color image by forming electrostatic latent images on a plurality of image carriers, developing the electrostatic latent images with toners of different colors for each of the image carriers to form toner images, sequentially transferring the toner images onto an intermediate transfer member in a superimposing manner, and collectively transferring the superposed toner images onto a sheet-like recording medium, the image forming apparatus comprising:
- an optical scanning device that scans a surface to be scanned with a light beam from a light source by a rotary polygon mirror and forms an image on the surface with a focusing optical system, the optical scanning device including a scanning-line-variation correcting unit that corrects a variation of a scanning line on the surface, wherein
- the scanning-line-variation correcting unit generates a variation of the scanning line of a curve component of equal to or higher than a third-order function having peaks at a plurality of portions along a main scanning direction, and offsets the curve component by generating a variation of the scanning line of an opposite shape.
An image forming apparatus for obtaining a color image by forming electrostatic latent images on a plurality of image carriers, developing the electrostatic latent images with toners of different colors for each of the image carriers to form toner images, sequentially transferring the toner images onto an intermediate transfer member in a superimposing manner, and collectively transferring the superposed toner images onto a sheet-like recording medium, the image forming apparatus comprising:
- an optical scanning device that scans a surface to be scanned with a light beam from a light source by a rotary polygon mirror and forms an image on the surface with a focusing optical system, the optical scanning device including a scanning-line-variation correcting unit that corrects a variation of a scanning line on the surface, the scanning-line-variation correcting unit that includes
- a first scanning-line-variation correcting unit that adjusts a first curve component of a quadratic function having a peak at one portion in a main scanning direction;
- and
- a second scanning-line-variation correcting unit that adjusts a second curve component of equal to or higher than a third-order function having peaks at a plurality of portions along a main scanning direction.
An image forming apparatus for obtaining a color image by forming electrostatic latent images on a plurality of image carriers, developing the electrostatic latent images with toners of different colors for each of the image carriers to form toner images, sequentially transferring the toner images onto an intermediate transfer member in a superimposing manner, and collectively transferring the superposed toner images onto a sheet-like recording medium, the image forming apparatus comprising:
- an optical scanning device that scans a surface to be scanned with a light beam from a light source by a rotary polygon mirror and forms an image on the surface with a focusing optical system, the optical scanning device including a focal-line varying unit that varies a focal line of an optical element having a convergent action at least in a sub-scanning direction from among optical elements constituting the focusing optical system, so that the focal line has peaks at a plurality of portions along a main scanning direction, wherein
- a variation of the focal line is corrected by the focal-line varying unit.
A method of correcting a variation of a scanning line formed on a surface to be scanned by a focusing optical system by mechanically applying a force to an optical element constituting the focusing optical system, the method comprising:
- dividing the variation of the scanning line into a curve component of a quadratic function having a peak in one portion in a main scanning direction and a curve component of equal to or higher than a third-order function having peaks at a plurality of portions along a main scanning direction;
- and
- correcting the curve component of the quadratic function and the curve component of the equal to or higher than a third-order function individually.
Dependencies are inferred from the claim text.