JPH0529012U - Lens holding structure - Google Patents

Abstract

(57) [Summary] [Object] To provide a lens holding structure that does not deteriorate optical performance by removing deformation while minimizing axial misalignment. [Structure] When a lens is fitted to a cylindrical frame 2 having an elastic projection made up of a rigid projection 2a and a leaf spring 2b on its inner circumference, the lens has a dimensional variation and a dimensional change due to the environment.
The elastic protrusion formed of the leaf spring 2b is easily deformed by being positioned by the rigid protrusion 2a. [Effect] Dimensional variations of both the lens and the barrel and temperature,
Even if the dimensions of the lens change due to the environment such as humidity, the lens can be held without being deformed while the axis shift is minimized, and deterioration of optical performance can be prevented.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a holding structure for a lens outer periphery in a lens holding structure, and more particularly to a holding structure that prevents deformation while minimizing lens axis misalignment and does not deteriorate the optical performance of the lens.

[0002]

[Prior Art]

 Conventionally, in the holding structure of the outer peripheral portion of a plastic lens, the outer peripheral portion of the lens and the fitting portion formed in the synthetic resin cylindrical frame are elastic, as described in JP-A-60-32017. Fitted through the body. Alternatively, as described in Japanese Utility Model Laid-Open No. 2-85412, there is no gap between the outer peripheral portion of the lens and the fitting portion formed in the synthetic resin cylinder frame, and no force is applied to each other. The most commonly used retaining structure is to prevent lens deformation.

[0003]

[Problems to be solved by the device]

 As described above, the conventional holding structure for preventing the deformation of the lens outer periphery has a structure in which the lens outer peripheral portion and the fitting portion in the cylindrical frame are fitted with each other without a gap and without applying a force to each other, or an elastic body. Although the design is such that the fitting between the fittings in the tube frame and the lens outer circumference is considered, considering the dimensional variation between the two and the dimensional change after fitting due to environmental changes such as temperature and humidity. There is no choice but to provide a gap between them or to insert an elastic body that makes it difficult to set the shaft in all fitting parts. As a result, the lens causes axial misalignment due to the gap between the lens and the force received from the elastic body, which significantly deteriorates the optical performance. Therefore, in order to prevent axial misalignment of the lens, if the inner diameter of the fitting portion inside the barrel is smaller than the outer diameter of the lens and the fitting is performed without using an elastic body, the lens receives force from the fitting portion inside the barrel. There is a problem in that the optical performance is significantly deteriorated due to the deformation. SUMMARY OF THE INVENTION An object of the present invention is to provide a lens holding structure that eliminates deformation while minimizing the axial displacement of the lens and does not deteriorate the optical performance.

[0004]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention uses two or more rigid protrusions and one or more elastic protrusions that are formed at an equal angle in a cylinder frame to hold the lens outer periphery with a tight fit so that the lens axis is By minimizing the displacement and providing one or more elastic protrusions, lens deformation does not occur even when held with a tight fit.

[0005]

[Action]

 According to the present invention, holding the outer periphery of the lens by a tight fit with a plurality of rigid body ridges and one or more elastic protrusions formed at an equal angle in the cylinder frame means that the dimensional variation and temperature Even if the dimensions change with time due to changes in the environment such as humidity, the outer circumference of the lens and the projection inside the barrel are always fitted together without a gap. Further, by providing rigid projections at a plurality of points, the axis of the lens is always positioned by the projections, so that when a plurality of lenses are assembled, the misalignment can be minimized.

[0006] Further, if the lens frame is fitted with one or more elastic projections, even if the lens outer periphery is held by an interference fit, only the elastic projections are greatly deformed, and the lens receives from the fitting portion. The power becomes weak. As a result, the deformation of the lens can be minimized. In addition, even if the dimensions change over time due to dimensional variations of both the lens and barrel and environmental changes such as temperature and humidity, and the degree of fitting changes, the lens deformation should be minimized. You can

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. The cylindrical frame structure of the holding structure for the lens outer periphery will be described with reference to FIG. Two rigid projections 2a and notches 3 are formed at an equal angle of 120 degrees on the circumference inside the cylinder frame 2 made of synthetic resin, and a leaf spring 2b is formed in the notch 3 in an arc toward the center of the cylinder frame 2. The leaf spring 2b is arranged as drawn, and the length of the leaf spring is determined so that the tip of the arc of the leaf spring 2b is about 0.1 mm smaller than the inscribed circle 2c of the fitting portion 4 of the protrusion 2a. The thickness must be sufficient and elastic enough not to prevent dimensional changes of the lens.

FIG. 2 shows a state in which the lens 1 is fitted in the cylindrical frame 2 having the structure shown in FIG. The lens 1 is held by a fitting part 4 of the rigid projection 2a of the tube frame 2 and a leaf spring 2b with a trough fit, and the axis of the lens is positioned by the fitting part of the rigid projection 2a of the tube frame 2. By being placed, the lens axis deviation can be minimized even in the interference fit structure with the dimensional variation of multiple lenses and the elastic body that makes it difficult to align the axis. Further, since the elastic protrusion of the plate spring 2b of the cylindrical frame 1 is easily deformed, the lens is not subjected to an excessive tightening force even when the dimension of the lens varies and the dimension changes after fitting due to the environment. It can be held without being deformed.

It should be noted that the height d of the leaf spring 2b needs to be high enough so that the leaf spring is not deformed and always comes into contact with the cylindrical frame 1.

In the above embodiment, the case where the lens holding points are three is described, but the same effect can be obtained even when the lens holding points are four or more. However, the elastic protrusions and the rigid protrusions must be arranged so that the forces applied to the lens are balanced.

[0011]

[Effect of the device]

 According to the present invention, even if the dimensional variation of both the lens and the barrel and the dimensional change due to the environment such as temperature and humidity can be maintained without deformation while keeping the axis deviation to a minimum, deterioration of optical performance is prevented. it can.

Further, since only one part is required to realize this, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view of a cylinder frame according to an embodiment of the present invention,

FIG. 2 is an explanatory view showing a state where a lens is fitted in the tubular frame having the structure shown in FIG.

FIG. 3 is an explanatory view of holding an outer circumference of a lens in a conventional cylinder frame.

[Explanation of symbols]

1 ... Lens, 2 ... Cylindrical frame, 2a ... Rigid protrusion, 2b ... Leaf spring (elastic protrusion), 2c ... Inscribed circle, 3 ... Notch, 4 ...
Fitting part, d ... Leaf spring height.

Claims (1)

[Scope of utility model registration request] 1. A lens barrel in which a plurality of lenses and a spacer ring are arranged in a cylindrical barrel made of synthetic resin.
Arranging a plurality of rigid protrusions arranged at an equal angle and one or more elastic protrusions so as to form a circumference, and holding the outer periphery of the lens with an interference fit at the tip of the rigid protrusion. Lens holding structure characterized by.