JPH0644268U - Optical scanning device - Google Patents

Abstract

(57) [Summary] [Object] To provide an optical scanning device capable of adjusting an optical path accurately and easily. In an optical scanning device configured to provide a casing with a light source, an optical deflector, and a mirror, and deflect and scan a light beam emitted from the light source by using the optical deflector and the mirror, a reference plane 20 is set in a casing 19. , One optical path L ₃ of the light beam defined by the mirrors 14 and 15
An optical scanning device characterized by being arranged in parallel with.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical scanning device having a structure in which a casing is provided with an optical deflector and a mirror, and a light beam emitted from a light source is deflected and scanned using the optical deflector and the mirror.

[0002]

[Prior art]

 Optical scanning devices have been widely used in image scanners and optical printers in recent years.

Generally, an optical scanning device is provided with an optical deflector such as a polygon mirror (rotary polygon mirror), and the polygon mirror is rotated at a high speed to deflect and scan a light beam emitted from a light source. .

In the image scanner, the aforementioned light beam scans the surface of the object as a scanning beam. For large image scanners, the scanning beam scanning width is correspondingly large. Therefore, it is very important to stabilize the scanning beam path in order to read the image of the surface of the object with high accuracy.

Usually, a light beam deflected and scanned by a polygon mirror is applied to an object through a plurality of mirrors. Therefore, some optical paths are defined by a plurality of mirrors in the casing. In order to finally stabilize the optical path of the scanning beam that scans the surface of the test object, it is necessary to strictly control the path of the optical beam inside the casing.

[0006]

[Problems to be solved by the device]

In the conventional optical scanning device, the optical path inside the casing is adjusted as follows. That is, as shown in FIG. 2, the predetermined optical path is separated from the first reference point P ₁ on the inner surface of the casing by the distance D _{1 in the} direction perpendicular to the reference surface, and the second reference point P ₂ on the inner surface. The mirror was adjusted so that it was separated by a distance D ₂ .

However, such an adjusting method is complicated and has a large error. This is because if the distance measurement location deviates even slightly from the reference point, the optical path cannot be adjusted accurately. In the case of a large-sized image sensor, even if the error of the light beam upstream is small, a large error will occur in the path of the scanning beam scanning the surface of the object to be inspected.

In view of the problems of the conventional techniques as described above, an object of the present invention is to provide an optical scanning device capable of accurately and easily adjusting an optical path.

[0009]

[Means for Solving the Problems]

The present invention is an optical scanning device in which a casing is provided with an optical deflector and a mirror, and a light beam emitted from a light source is deflected and scanned by using the optical deflector and the mirror, and a reference plane 20 is set on a casing 19. The optical scanning device is characterized in that one optical path L ₃ of the optical beam defined by the mirrors 14 and 15 is arranged parallel to the reference plane 20.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual diagram showing a large-sized image scanner equipped with an optical scanning device according to the present invention.

The image scanner 10 is mainly composed of an optical scanning system (device) 9 and a detection system 8. The optical scanning system 9 is provided in the casing 19. The detection system 8 is installed outside the casing 19.

First, the optical scanning system 9 will be described. A light source 11, a polygon mirror 13, fixed mirrors 12 and 14 to 16 are arranged in the casing 19. A semiconductor laser can be used as the light source 11. The polygon mirror 13 is also called a rotary polygon mirror and can rotate at high speed around a rotation axis.

The light beam emitted from the light source 11 is first reflected rightward by the first mirror 12 and is incident on the polygon mirror. Then, this light beam is deflected and scanned on the deflecting surface of the polygon mirror, and again reflected upward by the first mirror 12. In FIG. 1, the optical path from the polygon mirror to the first mirror 12 is indicated by the symbol L ₁ .

The light beam reflected upward by the first mirror 12 follows the optical path L ₂ and is reflected downward by the second mirror 14. The light beam is further reflected by the third mirror 15 and the fourth mirror 16 and scans the surface of the test object 18 below the casing 19 via the optical paths L ₃ , L ₄ and L ₅ . The scanning direction of the scanning beam is the direction perpendicular to the paper surface in FIG. By moving the test object 18 in the direction of the arrow, the entire test object 18 or a predetermined part can be scanned.

The scanning beam obtained by scanning the surface of the test object 18 is detected by the main light receiver 17 or the sub-light receiver 17 ′. The light beam detected by the light receiver 17 (17 ') is processed by the information processing unit 21.

A generally flat reference surface 20 is set on the inner wall of the casing 19. The present proposal is not limited to just such a reference plane 20. For example, it is possible to divide the reference plane into multiple parts and separate them.

The optical path L ₃ defined by the second mirror 14 and the third mirror 15 is arranged parallel to the reference plane 20. The optical path arranged parallel to the reference plane 20 may be an optical path other than L _{3 or} an optical path defined by only one mirror.

In the above-mentioned optical scanning device, the method of adjusting the optical path is very simple. That is, the distance between any two points on the reference plane 20 and the optical path L ₃ is adjusted so as to have a predetermined value D.

In the illustrated embodiment, the optical path L ₃ is the longest of all optical paths. Therefore, more accurate optical path adjustment can be performed by adjusting the distance from the reference surface 20 near both ends.

[0021]

[Effect of device]

In the optical scanning device of the present invention, since one path of the light beam (for example, L ₃ ) is arranged in parallel with the reference plane, the optical path can be adjusted easily and accurately.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an image scanner equipped with an optical scanning device of the present invention.

FIG. 2 is a conceptual diagram of an image scanner including a conventional optical scanning device.

[Explanation of symbols]

9 Optical scanning system 10 Image scanner 13 Optical deflector 12, 14, 15, 16 Mirror 19 Casing 20 Reference plane L ₁ , L ₂ , L ₃ , L ₄ , L ₅ Optical path P ₁ 1st reference point P ₂ 2nd reference Point ◆

Claims (1)

[Scope of utility model registration request] 1. An optical scanning device having a structure in which a light deflector and a mirror are provided in a casing, and a light beam emitted from a light source is deflected and scanned by using the light deflector and the mirror. ), Set the mirror (1
4. An optical scanning device, characterized in that one optical path (L ₃ ) of the light beam defined by 4, 4) is arranged parallel to the reference plane (20).