JPS6167002A - Multi-optical axis lens - 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 Application of the Invention] The present invention relates to a multi-optical axis lens used in an optical fiber gyro etc. The present invention relates to a multi-optical axis lens that is easy to define minutely and accurately.

[Background of the invention]

In the optical fiber gyro consisting of d, it is necessary to divide a bundle of parallel rays with a finite thickness and focus the number of beams with the same focal length.In such a case, conventionally,
For example, a multi-optical axis lens l consisting of a compound lens as shown in FIG. 2 has been used. Note that FIG. 2 shows a multi-optical axis lens 1 having four optical axes, and four convex lenses la, lb, lc, and ld, each having a mutually parallel optical axis.
It shows that it is composed of. As such a conventional multi-optical axis lens 1, four convex lenses having the same predetermined focal length are prepared in advance, and each of these four lenses is arranged as shown in FIG. The prismatic elementary lenses la to ld were left in the center, the peripheral portion 2 was cut off, and the thus obtained prismatic elementary lenses 1a to 1d were bonded together, and these were mainly used.

However, in such a conventional multi-optical axis lens, as shown in FIG. 4, the distance between the optical axes of the respective elementary lenses 1a and 1b is llI! Since d is determined by the dimension between the centers of these elementary lenses 1a and 1b, that is, the diameter of the elementary lenses (however, since these lenses are prismatic, it is the length of one side), this distance d must be made small. TameK)'! , the diameter (length of the side) of the elementary lenses 18 to 1d must be made small.

In addition, in this FIG. 4, La and Lb are incident parallel light and Fa.

Fb is the focal point of each lens la, lb.

Therefore, each of these five elementary lenses 1a to 1 (H
), its diameter (length of side) becomes smaller, which makes it difficult to manufacture, and it is extremely difficult to manufacture lenses of several millimeters or less at low cost and with high precision.

However, in the optical fiber gyro mentioned above, the distance between the optical axes is required to be on the order of several tens of micrometers, rather than on the order of millimeters as mentioned above. It was not possible to obtain a low-cost, high-precision axial lens.

An example of an optical fiber gyro requiring such a multi-optical axis lens is the invention disclosed in Japanese Patent Application No. 58-232751.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to easily obtain a distance between optical axes of several tens of micrometers or less with good accuracy, and to provide a multi-optical axis at low cost. To provide lenses.

[Summary of the invention]

In order to achieve this objective, the present invention has been developed to form a single lens when combined, such as aa lens pieces obtained by cutting a single lens symmetrically with respect to its optical axis. A plurality of lens pieces are positioned with a predetermined gap between their combined surfaces such as cut surfaces to form a point 1ks image as a multi-axis lens.

[Embodiments of the invention]

A multi-optical axis lens made from a single EIIJK will be explained in detail below using illustrated embodiments.

FIG. 1 shows an embodiment of the present invention, in which a single convex lens is cut into two pieces 3a and 3b at the center.

These are joined by sandwiching a sag material 4 having a thickness of the cut surface KPIr, and 5 represents 4 (contact layer) at the joint. In addition, the lens 3 shown with a dotted line shows the lens 3 before cutting.

Now, if the lens pieces 3a and 3b were cut along the plane passing through the optical axis of the original lens 30, each lens piece 3
The optical axis of a and 3b is straight paddy A passing through each cut UTrHJ.
tB, and these lens pieces 3a.

When the 3bK parallel beams La and Lb are incident, focal points F a and k' b appear on extensions of the respective optical axes A and B, respectively.

However, at ℃, the cut surfaces of these lens pieces 3a and 3b are bonded and fixed via a thin plate member 4, and as a result, between the optical axes A and B, the thin plate member 4 and the bonding layer 5 are placed with a spacer. A predetermined distance d is formed, and the lens functions as a multi-optical axis lens. In addition, in reality,
Since the thickness of the bonding layer 5 can be made extremely variable, the distance d is almost determined by the thickness of the thin plate member 4.

On the other hand, if gold MPi, for example, is used as the thin plate member 4, the tube 9 having the same thickness can be formed extremely easily down to the micron order.

Therefore, according to this implementation f%lK, 11 of 4ei member 4
Any minute distance between optical axes pI4 can be achieved by simply selecting the width.
A multi-optical axis lens that can provide d with high precision can be easily obtained at low cost.

It is possible to increase the Mf of optical fiber gyros and the like.

In the above embodiment, there are two lens pieces 3a.

3b is obtained by cutting one convex lens 3, and as a result, the lens pieces 3a and 3b having a predetermined shape can be easily obtained, but the present invention is not limited to this. , if the given shape is obtained,
Each lens piece 3a.

It goes without saying that 3b may be made independently and then joined.

Next, FIG. 5 shows another embodiment of the present invention, in which the embodiment of FIG. 1 is a lens with two optical axes, but it is implemented as a lens with four optical axes.

3a, 3b, 3c, and 3d are lens pieces obtained by cutting one lens 3 into four parts, and these pieces are assembled into four plate members 4.
and are bonded and fixed via the bonding layer 5.

According to the embodiment shown in FIG. 5, a lens having four optical axes can be obtained as in the conventional example shown in FIG. A multi-optical axis lens with a sufficiently small value and high precision can be easily obtained at low cost.

Furthermore, FIG. 6 also shows an embodiment of the present invention, in which the junction points of the four lens pieces 3a to 3d in the embodiment of FIG. Piece 3
b is shifted to the left side in the figure, and the lens piece 3d is further slid to the left side, and the lens piece 3C is shifted to the right side, so that the original axes of the valley lens pieces 3a to 3d are set to the 4th edition as in the case of the alignment in Fig. 5. 4 by the distance determined by the thickness of the member 4.
ft.

In addition to making it an axial lens, the focal position of each lens piece due to parallel light is left - for the focal point FaK of the lens piece 3a, the focal point Fb of the lens piece 3b, and the focal point Fd of the lens piece 3d.
1, and the illumination point Fc- of the lens piece 3c appears shifted to the right.

Therefore, according to this embodiment, it is possible to easily obtain at low cost a multi-optical axis lens that has four optical axes with a sufficiently small distance d maintained at all times and has a well-defined focal position.

In the above embodiment, the thin plate member 4 is used as a spacer for each lens piece, but if the distance d' between optical axes is further reduced, this scattered member 4 may be eliminated and only the bonding layer 5 used. may be interposed.

Furthermore, the board member 4 is not limited to metal foil, but may also be a thin plate of plastic or glass.

Additionally, one of these materials can be applied to the cemented surface of the lens piece (
It may also be used as a spacer by attaching it to a predetermined thickness by steaming or the like on the mating surface.

On the other hand, each lens piece is not limited to a general optical glass lens, but may also be formed of quartz glass, plastic, multi-component glass, etc. Moreover, it is not limited to a single lens structure, but may also be a bonded compound lens. Needless to say.

〔Effect of the invention〕

As explained above, according to the present invention, the distance between the optical axes can be determined only by the thickness of the spacer, regardless of the size of the lens piece. A multi-optical axis lens having a sufficient distance distance can be easily provided at low cost.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an embodiment of the multi-optical axis lens according to the present invention, Fig. 2 is a perspective view showing a conventional example of the multi-optical axis lens, Fig. 3 is an explanatory diagram of its manufacturing method, and Fig. 4 1 is an explanatory diagram showing problems with the conventional multi-optical axis lens, and FIGS. 5 and 6 are explanatory diagrams each showing another embodiment of the present invention. 3a to 3d... Lens piece, 4... Root-like member, 5... Bonding layer. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. Forming one lens when combined,
A multi-optical axis lens comprising a plurality of lens pieces symmetrical with respect to the optical axis of the lens, which are bonded and fixed at their combined surfaces via a spacer of a predetermined thickness. . 2. The multi-optical axis lens according to claim 1, wherein the plurality of lens pieces are cut from one lens. 3. A multi-optical axis lens according to claim 1, characterized in that the plurality of lens pieces are bonded and fixed parallel to the optical axis of the lens and deviated from each other by a predetermined distance. 4. In claim 1, the spacer comprises:
A multi-optical axis lens characterized in that only an adhesive is used to fill between the combined surfaces of the plurality of lens pieces. 5. The multi-optical axis lens according to claim 1, wherein the spacer is composed of an adhesive layer and a thin plate member having a substantially uniform thickness.