JP2010066297A - Fixing method of optical element, optical scanning device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing method of an optical element capable of acquiring a desired adhesion area, applying widely an adhesive onto the whole adhesion domain on an adhesive surface of a cylindrical lens, and preventing peeling caused by deficiency of an adhesive strength or decline of an optical characteristic caused by turning-around to a lens surface, and to provide an optical scanning device and an image forming device using the method. <P>SOLUTION: In this fixing method of the optical element for sticking and fixing the cylindrical lens 4 with an adhesive 21 onto the first casing 14, the cylindrical lens 4 having a narrow gap groove 35 formed thereon is stuck and fixed onto an adhesive seat surface 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for bonding and fixing optical elements used in digital copying machines, laser printers, and the like.

  Optical scanning devices are widely used in digital copying machines and laser printers.

  As a technique related to fixing an optical element used in an optical scanning device at a predetermined position, there is a “light source device” disclosed in Patent Document 1. The invention described in Patent Document 1 attempts to improve the adhesive strength of the collimator lens by adhering and fixing the collimator lens to a holding member at a plurality of outer peripheral portions.

  The quality degradation of the optical scanning device includes mechanical degradation represented by an optical element mounting error, shape error, and the like, and temperature characteristic degradation due to a temperature change of the device.

  Regarding mechanical degradation, a method of absorbing degradation during assembly, such as mounting while adjusting an optical element, is widely used, and a number of proposals have been made regarding adjustment methods related thereto.

  When performing the adjustment, there is a problem of at which point in the assembly the adjustment is to be performed and from which optical element is to be adjusted. Depending on the setting, the developability of the adjustable range and the assembly method varies.

  Therefore, how to select the adjustment method and the adjustment order is as important as the design of the optical system.

  Patent Document 2 discloses an optical scanning device that aims to improve the quality of a scanning line, adjusts the position of a scanning lens (fθ lens) and a cylindrical lens with an adhesive applied, and irradiates and fixes ultraviolet light after adjustment. An adjustment method is disclosed.

In addition, by providing an adhesive reservoir near the bonding position, it is possible to prevent excessive adhesive from adhering to the effective surface of the optical element, thereby suppressing accuracy changes before and after bonding and preventing deterioration of optical performance. It is disclosed.
JP 2004-158586 A JP-A-7-234370

  However, if an adhesive is applied to the central part of the adhesive seating surface of the housing, the adhesive is not applied to the entire adhesive region of the cylindrical lens, and the desired adhesive area cannot be obtained. There is a risk of peeling due to insufficient adhesive strength.

  In addition, if adhesive is applied to multiple locations in the center of the adhesive seating surface of the housing, the adhesive spreads in areas other than the adhesive area on the cylindrical lens adhesive surface, causing problems such as wrapping around the lens surface and causing optical problems. There is a risk of deteriorating the characteristics.

  The present invention has been made in view of such problems, and it is possible to obtain a desired bonding area without complicating an apparatus such as an adhesive dispenser and a manufacturing process or increasing the cost unnecessarily, and the bonding surface of the cylindrical lens. A method for fixing an optical element capable of preventing an adhesive from spreading over the entire adhesive region and preventing peeling due to insufficient adhesive strength and deterioration of optical characteristics due to wrapping around the lens surface, and an optical scanning device and an image forming apparatus using the same The purpose is to provide.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a method for fixing an optical element in which an optical element is bonded and fixed to a fixing member with an adhesive. An optical element fixing method for bonding and fixing to a surface is provided.

  In order to achieve the above object, the present invention provides, as a second aspect, an optical scanning device comprising an optical element bonded and fixed by the optical element fixing method according to the first aspect of the present invention. A device is provided.

  In order to achieve the above object, the present invention provides, as a third aspect, an image forming apparatus equipped with the optical scanning device according to the second aspect of the present invention.

  According to the present invention, a desired adhesion area can be obtained, and the adhesive is spread over the entire adhesion area of the cylindrical lens adhesion surface, preventing peeling due to insufficient adhesion strength and deterioration of optical characteristics due to wrapping around the lens surface. An optical element fixing method that can be used, and an optical scanning device and an image forming apparatus using the same can be provided.

  FIG. 1 shows a housing according to this embodiment. The casing holds a first casing 14 that holds the light source 1, the coupling lens 2, the aperture 3, the cylindrical lens 4, the optical deflector 5, and the scanning lens 6, and a bending mirror 7 that is a light guide optical element. The second casing 15 is composed of two casings.

  At the time of adjustment, the position and posture of the main scanning plane of the coupling lens 2, the cylindrical lens 4, and the scanning lens 6 are adjusted by measuring the adjustment light beam 16 using only the first housing 14, and the adhesive 21 is used. Use and glue. The adhesive 21 is an acrylic ultraviolet curable adhesive, and for example, UVSERIES PC-2 manufactured by Denki Kagaku Kogyo Co., Ltd. is applicable.

  As the adjustment method, a known method as disclosed in Japanese Patent Application Laid-Open No. 2007-249002 can be applied, and detailed description thereof is omitted.

  Hereinafter, a case where the cylindrical lens 4 is fixed will be described as an example, but the same applies to a case where other optical elements are fixed.

  As shown in FIG. 2, the cylindrical lens 4 is made of plastic or glass and has a substantially semi-cylindrical shape. The incident surface 31 has no refractive power on the incident side of the beam 30 and has a curvature on the outgoing side. And a bonding surface 33 on the lower surface parallel to the main emission direction of the beam light.

  The adhesive surface 33 has an adhesive region 34 in the center, and a slit groove 35 that is a hairline-shaped fine groove is formed in the adhesive region 34. The narrow groove 35 is formed in parallel to the longitudinal ridge line 34a of the bonding region 34, and has a desired bonding area. For example, it is preferable to form several tens of slit grooves 35 with a depth of about 0.3 mm and a width of about 0.1 mm.

  As shown in FIG. 3A, when an adhesive is applied to one central portion of the adhesive seating surface 20 of the first housing 14, the adhesive surface 33 of the cylindrical lens 4 is applied as shown in FIG. Thus, the adhesive 21 does not spread over the entire bonding region 34, and a desired bonding area cannot be obtained.

  Further, when a large amount of adhesive is applied to obtain a desired bonding area, the adhesive 21 is applied to a plurality of central portions of the bonding seating surface 20 of the first housing 14 as shown in FIG. When applied, as shown in FIG. 4 (b), the adhesive 21 spreads out in addition to the adhesive region 34 on the adhesive surface 33 of the cylindrical lens 4, causing problems such as wrapping around the entrance surface 31 and the exit surface 32. End up.

  Therefore, as shown in FIG. 5, using the adhesive dispenser 22, the adhesive 21 is applied to one central portion of the adhesive seating surface 20 of the first housing 14, and the cylindrical lens 4 is placed thereon. As shown in FIG. 6, the adhesive region 34 and the adhesive 21 come into contact with each other, and the adhesive 21 advances in the direction indicated by the arrow along the slit groove 35 formed in the adhesive region 34. A desired adhesion area can be obtained by spreading in the region 34.

  Further, even when the application amount of the adhesive 21 is large, the adhesive 21 is cylindrical along the slit grooves 35 formed in the adhesive region 34 as shown in FIGS. By wetting and spreading toward the side wall surface 4 a side at both ends in the longitudinal direction of the lens 4, wraparound to the entrance surface 31 and the exit surface 32 can be prevented.

  Even when the application amount of the adhesive 21 is small, the adhesive 21 is cylindrical along the slit groove 35 formed in the adhesive region 34 as shown in FIGS. Proceeding toward the side wall surface 4a at both ends of the lens 4 in the longitudinal direction, wetting and spreading into the adhesion region 34, a desired adhesion area is obtained.

As described above, the fixing method of the optical element according to the present embodiment spreads and spreads the adhesive on the entire bonding area provided on the optical element such as the cylindrical lens, so that a desired bonding area can be obtained, and the adhesive is cured. A tough adhesive strength is obtained.
Furthermore, even if variations in the amount of adhesive applied due to temperature changes in the environment of use, the adhesive spreads over the entire bonding area along the slit groove formed in the bonding area, so a desired bonding area is obtained, A tough adhesive strength is obtained after the adhesive is cured.

  Since the optical characteristics can be stabilized by fixing the optical element in this manner, a highly accurate optical scanning device can be provided. Also, by mounting such an optical scanning device on an image forming apparatus, it is possible to obtain a high-quality image.

In addition, the said embodiment is an example of suitable implementation of this invention, and this invention is not limited to this. For example, in the above-described embodiment, the case where an ultraviolet curable adhesive is used has been described as an example. However, the optical element is bonded and fixed to the first housing 14 using an electron beam curable adhesive or a thermosetting adhesive. Also good.
As described above, the present invention can be variously modified.

1 is a diagram illustrating a configuration of an optical scanning device according to a preferred embodiment of the present invention. It is a figure which shows the structure of a cylindrical lens. It is a figure which shows the fixing method of the conventional optical element. It is a figure which shows the fixing method of the conventional optical element. It is a figure which shows the state by which the adhesive agent apply | coated to the center part of an adhesive seat surface is spread by a cylindrical lens. It is a figure which shows a mode that an adhesive agent spreads along a slit groove. It is a figure which shows the state which wets and spreads to a side wall surface side, and the wraparound to an incident surface and an output surface is prevented when the application amount of an adhesive agent is large. It is a figure which shows the state which wets and spreads to the side wall surface side, and an adhesion area is ensured when there are few application amounts of an adhesive agent.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Coupling lens 3 Aperture 4 Cylindrical lens 4a Side wall surface 5 Optical deflector 6 Scan lens 7 Bending mirror 14 1st housing | casing 15 2nd housing | casing 20 Adhesive seating surface 21 Adhesive 30 Beam light 31 Incident surface 32 Outgoing surface 33 Adhesion surface 34 Adhesion area 34a Edge line of adhesion area 35 Slot groove

Claims (6)

An optical element fixing method in which an optical element is bonded and fixed to a fixing member with an adhesive,
An optical element fixing method comprising: fixing an optical element having a slit groove to an adhesive seating surface.   The method of fixing an optical element according to claim 1, wherein the slit groove is formed in a longitudinal direction of an adhesive surface of the optical element.   The method of fixing an optical element according to claim 2, wherein the slit groove is formed in parallel to a longitudinal ridge line of the adhesion surface.   The method for fixing an optical element according to claim 1, wherein the adhesive is an ultraviolet curable adhesive.   An optical scanning device comprising: an optical element bonded and fixed by the optical element fixing method according to claim 1.   An image forming apparatus equipped with the optical scanning device according to claim 5.

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