JPH04180006A - Optical lens for optical scanner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an optical lens for an optical scanning device used in an imaging optical system of an optical scanning device used, for example, in a digital copying machine or a laser beam printer. It is.

[Prior Art] Conventionally, in an optical scanning device in which a laser beam emitted from a laser light source is scanned by a deflector to form an image on a photoreceptor, for example, Japanese Patent Publication No. 62-36210 and U.S. Pat. As disclosed in Japanese Patent No. 4639072, it has become common to use a toric lens, cylindrical lens, etc. as a correction optical system in the imaging optical system in order to correct the surface tilt of a rotating polygon mirror. There is.

Furthermore, as a method of fixing such a wide optical lens to an apparatus, a method is often adopted in which a spring material such as a sheet metal or plastic is pressed against the optical lens and the material is fixed with a screw. In addition to this, optical lenses are also bonded and fixed using various adhesives.

As a typical example, FIG. 8 shows a conventional example in which a glass lens 1 is bonded to a base 3 via an ultraviolet curing adhesive layer 2. In this case, the ultraviolet rays from the ultraviolet irradiation device 4 are The edge portion 1b of the glass lens 1, which is perpendicular to the lens surface 1a, is irradiated with light.

[Problems to be solved by the invention] The method of pressing an optical lens with a spring material and fixing it with a screw requires spring material, screws, screw holes, etc.
The drawback is that it requires a large number of parts and is relatively expensive.

In addition, as shown in FIG. 8, in the method of fixing with adhesive, the light for curing the adhesive is applied to the edge portion 1b of the lens 1.
Since the adhesive layer is irradiated from above, the light is scattered by the rough surface of the edge portion 1b, causing a problem in that the light reaching the adhesive layer is weakened and the amount of light varies. Furthermore, if the glass lens 1 has a low transmittance of ultraviolet rays, in order to cure the ultraviolet curable adhesive, it is necessary to extend the irradiation time, which increases the takt time and increases the cost. If the ultraviolet rays are too strong, there is a risk of causing chemical changes and adversely affecting other parts, and if the adhesive strength is too strong, the lens surface 1a
There is also the problem of distorting the

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide an optical lens for an optical scanning device with high mounting accuracy and high adhesion rate.

[Means for Solving the Problems 1] In order to achieve the above-mentioned object, an optical lens for an optical scanning device according to the present invention is an optical lens used in an imaging optical system of an optical scanning device, and a lens The device is characterized in that it has a non-lens portion that is wider than the edge portion of the lens, and that the non-lens portion is bonded to a base.

[Function] The optical lens for an optical scanning device having the above-mentioned configuration weakens the adhesive force per unit area by bonding the non-lens portion, which is wider than the edge portion of the lens, to the base, and prevents the lens from forming due to excessive adhesive force. Reduce surface distortion.

[Example] The present invention will be described in detail based on the example illustrated in FIGS. 1 to 7.

1 to 3 show an example of a toric lens to which the present invention is applied. This type of toric lens is known from the aforementioned Japanese Patent Publication No. 62-36210 and US Patent No. 463.
It can be used in an optical system for correcting the surface inclination of a rotating polygon mirror as described in Japanese Patent No. 9072, and the refractive power in the longitudinal direction of the lens is different from the refractive power in the short side direction.

In this toric lens 10, the lens portion 10a
Plano-convex non-lens portions 10b are integrally provided on both sides of the lens. Here, the dimension A of the non-lens portion 10b is sufficiently larger than the edge dimension B of the lens portion 10a. In FIG. 2, rl and r2 indicate lens surfaces in the short side direction of the lens, and in this embodiment, both have a spherical meniscus shape. On the other hand, the lens surface in the longitudinal direction, R2, is
As shown in Fig. 3, both have an aspherical meniscus shape, and are bonded at three locations: Sl, S2, and S3.

FIG. 4 shows how this toric lens 10 is adhered to the base 11, 12 is an ultraviolet curing adhesive layer, x, y
, z indicate the irradiation direction of the ultraviolet irradiation device 13, respectively. Here, since the toric lens 10 is molded from a synthetic resin material whose UV transmittance is considerably lower than that of the general glass material BK7, when bonding it,
X, Y where the thickness of the synthetic resin material is thinner than when irradiating from the direction
It is more effective to irradiate from this direction. Further, as described above, the dimensions of the non-lens portion 10b are larger than the edge dimensions of the lens portion 10a, and the bonding area of the non-lens portion 10b can be made sufficiently large, so that the adhesive force per unit area can be weakened. Therefore, the problem of distortion of the lens surface due to localized strong adhesive force is solved.

In this way, when fixing the lens 10 with adhesive, the non-lens part 1 which has a wider area than the edge part of the lens 10 is used.
By providing 0b, distortion of the lens surface can be reduced, and mounting accuracy and adhesion rate can be increased.

In the above-described embodiment, an example was shown in which the present invention was applied to a wide toric lens 10, but it goes without saying that the present invention can also be applied to other similar cylindrical lenses, spherical lenses, etc.

Further, as shown in FIG. 5, a non-lens portion 10c may be added to a portion of the edge of the lens 10, and the non-lens portion 10c may be used for adhesive fixation.

Furthermore, as shown in FIG. 6, the non-lens portion 10b may be provided only on the edge portion of the lens portion 10a on the adhesive side, or as shown in FIG. Even if the non-lens portion 10d is provided, the lens 10 can be fixed with adhesive in the same manner.

"Effects of the Invention" As explained above, in the optical lens for an optical scanning device according to the present invention, since the area of the adhesive part of the non-lens part is wider than the edge part of the lens, the adhesive force per unit area is weakened. Surface distortion can be alleviated and positioning can be performed with high precision.Also, when using a photocurable adhesive, the light path length that passes through the material is short, so the light that reaches the adhesive layer is weak. It is possible to increase the adhesion efficiency without causing curling or variations in the amount of light.It is also suitable for planar polarized lenses such as wide-width toric lenses and cylindrical lenses, and eliminates the problem of complex external shapes. This problem can be solved by molding synthetic resin.

[Brief explanation of the drawing]

1 to 7 show an embodiment of the optical lens for an optical scanning device according to the present invention, FIG. 1 is a perspective view of a toric lens, FIG. 2 is a cross-sectional view of the lens in the short side direction, and FIG. The figure is a side view seen from the non-lens part, Figure 4 is an explanatory diagram of the bonded state,
FIGS. 5 to 7 are configuration diagrams of other embodiments, respectively.
The eighth section is a configuration diagram of a conventional example. Reference numeral 10 is a toric lens, lOa is a lens portion, 10
b, loc, and 10d are non-lens parts, 11 is a base, 12 is an adhesive layer, and 13 is an ultraviolet irradiation device. Patent Applicant Canon Co., Ltd., +-1 Patent Attorney Yukihiko Hibiya - Figure 1 Figure 3 Figure 4\ Figure 5 11 Figure 6

Claims (1)

[Scope of Claims] 1. An optical lens used in an imaging optical system of an optical scanning device, which has a non-lens part wider than the edge of the lens, and the non-lens part is adhered to a base. An optical lens for an optical scanning device characterized by: 2. The optical lens for an optical scanning device according to claim 1, wherein the adhesive for bonding the non-lens portion is a photocurable adhesive. 3. The optical lens for an optical scanning device according to claim 1, wherein the optical lens is made of a synthetic resin material, and the adhesive for bonding the non-lens portion is an ultraviolet curing adhesive.