Lens mirror array, optical unit and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9778591-B2
Application number	US-201514933071-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Jan 27, 2015
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

An example is a lens mirror array in which a plurality of optical elements, which comprises a first lens surface formed at the top of convex portion protruding outwards for converging light, a protrusion which includes a first mirror surface that reflects the light emitted from the first lens surface at the top and a light-shielding surface that has side walls at two sides thereof with respect to a light advancing direction and prevents advance of the light through the side walls, a second mirror surface that reflects the light reflected by the first mirror surface of the protrusion and a second lens surface that images the light emitted from the second mirror surface on an image plane, is arranged in a horizontal scanning direction.

First claim

What is claimed is:

1. A lens mirror array, comprising:
a plurality of optical elements each optical element comprising
a first lens surface at a top of a convex portion protruding outwards and configured to converge light,
a protrusion comprising a first mirror surface configured to reflect the light emitted from the first lens surface at the top and a light-shielding surface having side walls at two sides thereof with respect to a light advancing direction and configured to prevent advance of the light through the side walls,
a second mirror surface configured to reflect the light reflected by the first mirror surface of the protrusion, and
a second lens surface configured to image the light emitted from the second mirror surface on an image plane,

the plurality of optical elements arranged in a horizontal scanning direction; and
when viewing the first lens surface side between the side-wall surfaces of arranged adjacent optical elements in a horizontal scanning direction, the protrusion keeps a predetermined distance with the first lens surface and a principal ray of the light emitted from the first lens surface is formed into a shape protruding towards the first lens surface side.

2. The lens mirror array according to claim 1 , wherein,
a light-shielding film is formed on the side walls at two sides of the protrusion and on the surface of the surface of the first lens surface side between the side-wall surfaces of the adjacent optical elements.

3. The lens mirror array according to claim 2 , wherein
the light-shielding film is coated with UV ink.

4. An optical unit, comprising:
a light source array comprising a light source to emit light; and
a lens mirror array comprising a plurality of optical elements, each optical element comprising
a first lens surface at a top of a convex portion protruding outwards and configured to converge the light emitted from the light source array,
a protrusion comprising a first mirror surface configured to reflect the light emitted from the first lens surface at the top and a light-shielding surface having side walls at two sides thereof with respect to a light advancing direction and configured to prevent advance of the light through the side walls,
a second mirror surface configured to reflect the light reflected by the first mirror surface of the protrusion, and
a second lens surface configured to image the light emitted from the second mirror surface on an image plane,

the plurality of optical elements is arranged in a horizontal scanning direction; and
when viewing the first lens surface side between the side-wall surfaces of arranged adjacent optical elements in a horizontal scanning direction, the protrusion keeps a predetermined distance with the first lens surface and a principal ray of the light emitted from the first lens surface is formed into a shape protruding towards the first lens surface side.

5. An image forming apparatus, comprising:
a light source array comprising a light source to emit light;
a lens mirror array comprising a plurality of optical elements, each optical element comprising
a first lens surface at a top of a convex portion protruding outwards and configured to converge the light emitted from the light source array,
a protrusion comprising a first mirror surface configured to reflect the light emitted from the first lens surface at the top and a light-shielding surface having side walls at two sides thereof with respect to a light advancing direction and configured to prevent advance of the light through the side walls,
a second mirror surface configured to reflect the light reflected by the first mirror surface of the protrusion, and
a second lens surface configured to image the light emitted from the second mirror surface on an image plane,

the plurality of optical elements is arranged in a horizontal scanning direction; and
when viewing the first lens surface side between the side-wall surfaces of arranged adjacent optical elements in a horizontal scanning direction, the protrusion keeps a predetermined distance with the first lens surface and a principal ray and is formed into a shape protruding towards the first lens surface side;
a photoconductor comprising a photoconductive surface on the image plane to form an latent image thereon; and
a developing section configured to visualize the latent image formed on the photoconductor.

Assignees

• Toshiba Tec Kk

Inventors

• Shiraishi Takashi

Classifications

• G03G15/0409 Primary

  Details of projection optics (for projection printing apparatus G03B27/522) · CPC title

• G02B17/002

  Arrays of reflective systems · CPC title

• G03G2215/0132

  vertical medium transport path at the secondary transfer · CPC title

• G02B17/086

  wherein the system is made of a single block of optical material, e.g. solid catadioptric systems · CPC title