JPS62187808A - Lens holder - Google Patents

Abstract

PURPOSE:To reduce the deformation of a lens barrel made of resin and to fix the lens barrel accurately for a long period by providing an external frame, a hole part almost perpendicular to an optical axis, a long hole part arranged opposite the hole part, and a fixing member which fixes the hole part and long hole part. CONSTITUTION:When assembly and adjustment are performed, lenses 21-23 are inserted into one split lens barrel 20 firstly, which is covered with the other split lens barrel 20 to complete a master lens part 36; and the master lens part is fitted in a master flange 37 and a fixing screw 41 is inserted into the long hole 40 formed in the master flange 37 and clamped lightly in the screw hole 35 of the split lens barrels 20. Then, an eccentric pin is inserted into the guide hole 42, the tip of the eccentric pin is engaged with the groove 33 of the split lens barrel 20, and the eccentric pin is moved in the optical axis direction of the master lens part 36 to make a back focus adjustment. At this time, a projection part and a recessed part 38 engage each other, so the master lens part 36 is guided in the recessed part 38 to move in the optical-axis direction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a lens holding device that can be used in optical equipment such as video cameras.

BACKGROUND OF THE INVENTION In recent years, the applications of optical-related equipment have rapidly expanded due to advances in electronics, and along with this, the demand for improved productivity has also increased. Attempts are being made to improve productivity and reduce costs by using resin for so-called lens barrels that support optical elements.

Hereinafter, an example of the conventional lens assembly mentioned above will be described with reference to the drawings.

FIG. 6 shows a perspective view of a conventional lens holding device, and the structure in which a lens barrel 2 holding several lens groups (1 is one of them) is fixed to another lens barrel 3 is as follows: This is often used to fix a so-called master lens group. To explain in more detail, the lens barrel 3 is supported on the device main body through the mounting hole 5 provided in the 7 flange portion 4 of the lens barrel 3, the lens barrel 2 is fitted inside the lens barrel 3, and the lens barrel The groove 6 provided in the lens barrel 3
After that, using the eccentric pin 1Q in which the shaft 8 and filj9 are eccentric, the shaft 9 is engaged with the hole 7, and the shaft 8 is inserted into the groove 6. By rotating the eccentric pin 10 in the engaged state, the lens barrel 2
Adjust the back focus by moving all lenses in the optical axis direction. After the adjustment is completed, screw the screw 12 into the screw hole 11 provided in the lens barrel 3, press the tip of the screw 12 against the lens barrel 2 and fix it, and then remove the eccentric bottle. Focusing of the lens system is completed.

Problems to be Solved by the Invention [7]However, with the above configuration, there is no problem at all in the case of a lens barrel using metal parts, but in the case of a lens barrel using resin materials, there may be problems during use. There was a risk that the tightening force of the screws would decrease due to changes over time, and the position of the lens barrel would move, causing the focus to shift.

Furthermore, there is a problem in that the tightening force of the screw increases by the amount of the decrease in tightening force, and if the screw is tightened strongly in advance, the lens barrel will be deformed and the optical performance will deteriorate.

In view of the above-mentioned problems, the present invention provides a lens holding device that accurately fixes a lens barrel made of resin material over a long period of time.

Means for Solving the Problems In order to solve the above problems, the lens holding device of the present invention includes a lens barrel that accommodates a lens and is movable in the optical axis direction;
an outer frame for holding the outer periphery of the lens barrel; a hole provided in a side surface of the lens barrel in a direction substantially perpendicular to the optical axis; and a hole provided in the outer frame at a position facing the hole. A fixing member is provided for fixing the hole and the elongate hole.

Effects of the Invention With the above-described configuration, the present invention does not directly press the outer periphery of the lens barrel with a strong force, so that the lens barrel is less deformed and the resin lens barrel can be accurately fixed for a long period of time.

EXAMPLE Hereinafter, a lens holding device according to an example of the present invention will be described with reference to the drawings.

Fig. 1 is a sectional view of a lens holding device according to an embodiment of the present invention, Fig. 2 is a side view thereof, Fig. 3 is a plan view of the main part thereof, and Fig. 4 is a perspective view of the master lens section. be. In FIGS. 1 to 4, two identically shaped split lens barrels 20 made of glass and polycarbonate resin each have a lens 2.
1,22°23 is inserted. The outer peripheral part of the lens 21 is held by a lens holding part 24 on the inner peripheral surface of the divided lens barrel 2o, and an elastic piece 26 provided on the inner surface of the divided lens barrel 2o.
By pressing the lens 21 against the lens regulating portion 26, positioning in the optical axis direction is performed. Similarly, the lens 22 is attached to the lens holding portion 279 of the split lens barrel 20, the elastic piece 28. Fixed by the lens regulating part 29, the lens 2
3 is a lens holding part 30. Elastic piece 31. Lens regulation section 32
Fixed by

The outer periphery of the split lens barrel 20 has a groove 33 in the circumferential direction and an optical axis 34.
A screw hole 36 is provided in a direction substantially perpendicular to the master lens portion 36, and a master lens portion 36 composed of two divided lens barrels 2o and lenses 21, 22° and 23 is housed in a master flange 37. In this case, the recess 3 provided in the master flange 37
8 and a convex portion 39 provided on the split lens barrel 20 engage with each other, and the optical axis 3
Positioning in the rotational direction with respect to 4 is performed. Also,
The master flange 37 has an elongated hole 40 at a position facing the screw hole 35, and a fixing screw 41 is inserted through the elongated hole 40.
It is configured so that it can be tightened into the screw hole 36 of the split lens barrel 20. Furthermore, the elongated hole 40 of the mask-flange 37
On the opposite side, there is provided a guide hole 42 for an eccentric bin (not shown) for finely adjusting the master lens portion 3θ in the optical axis direction.

When assembling and adjusting the lens holding device of this embodiment configured as described above, first insert one of the divided lens barrels 20 [lenses 21, 22, and 23], and then insert the other divided lens barrel 20. The completed master lens part 36 is covered and fitted onto the master flange 37, and the fixing screw 41 is lightly tightened into the screw hole 36 of the split lens barrel 20 through the elongated hole aof provided in the master flange 37.

Next, an eccentric bottle similar to the conventional example is inserted into the guide hole 42, the tip of the eccentric bottle is engaged with the groove 33 of the divided lens barrel 2o, and the master lens section 36 is moved in the optical axis direction by rotating the eccentric bottle. to adjust the puck focus. At this time, since the convex part 39 and the concave part 38 are engaged, the master lens part 36 is guided by the concave part 38 and can move only in the optical axis direction. After the adjustment is completed, the fixing screw 41 is strongly tightened, the eccentric pin is removed from the master flange 37, and the bank focus adjustment is completed.

As described above, according to this embodiment, there is an outer frame for holding the outer periphery of the lens barrel, a hole provided on the side surface of the lens barrel in a direction substantially perpendicular to the optical axis, and a position facing the hole. Equipped with an elongated hole located in the outer frame and a fixing member that fixes the hole and the elongated hole, there is less deformation of the lens barrel and the resin lens barrel can be fixed accurately for a long period of time. can.

Effects of the Invention As described above, according to the present invention, even when the fixing screw is tightened with a strong force, the outer periphery of the lens barrel is not directly pressed with a strong force, so the lens barrel does not deform and the optical performance is not deteriorated. There is no. Therefore, even if the lens barrel is made of resin material,
This provides the excellent effect of being able to fix the lens barrel with high precision over a long period of time without worrying that the position of the lens barrel will shift due to changes over time.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a lens holding device according to an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a plan view of the main part thereof, and FIG. FIG. 6 is a perspective view of a conventional lens holding device. 20-1...Divided lens barrel, 21, 22.23...
Lens, 35...screw hole, 3a...master flange, 4o...elongated hole, 41...fixing screw. Name of agent: Patent attorney Toshio Nakao and 1 other person 20
...9 劃餞体J Fig. 5 1θ

Claims (1)

[Claims] A lens barrel that accommodates a lens and is movable in the optical axis direction, an outer frame for holding the outer periphery of the lens barrel, and a hole provided in a side surface of the lens barrel in a direction substantially perpendicular to the optical axis. 1. A lens holding device comprising: a long hole provided in the outer frame at a position facing the hole; and a fixing member for fixing the hole and the long hole.