JPH1020211A - Reversal optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a reversal optical system of an optical device thin in thickness without raising cost. SOLUTION: This optical system is provided with a roof reflection mirror 102 and a prism 16a arranged to face each other. Light entering the prism 16a from an objective side exits toward the mirror 102, is reflected on the mirror 102, returned to the prism 16a, reflected on one surface of the prism 16a and advances to an eyepiece side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device such as a camera or binoculars, and more particularly to a reversing optical system used for a flat and thin optical device.

[0002]

2. Description of the Related Art As a reversing optical system used in an optical apparatus, a reversing optical system of a Porro prism type combining two triangular prisms,
A roof type in which a roof prism having a right-angled surface and an auxiliary prism are combined is generally known.

[0003] Porro-prism type reversing optical systems can be manufactured at low cost, but have the disadvantage of increasing the size of the product. On the other hand, the roof type reversing optical system is easy to manufacture compactly and is suitable for making the binoculars thinner, but has a disadvantage of high cost.

In other words, in order to reduce the thickness of the optical device, it is preferable to use a roof type reversing optical system. In this case, however, there is a problem in how to reduce the manufacturing cost.

[0005]

Means, Action, and Effect for Solving the Problems In order to suppress an increase in cost, it is conceivable to employ a mirror instead of the prism. However, if both the roof prism and the auxiliary prism are replaced with mirrors, the size of the product is increased. Therefore, in the present invention, of these two prisms, only the one that has little effect on the size of the product when replaced with a mirror, that is, only the one with a small transmission / reflection shared surface, is replaced with a mirror, It achieves both thinning and cost reduction.

That is, an inverting optical system according to one embodiment of the present invention includes a roof reflecting mirror and a prism which are arranged to face each other. The roof reflecting mirror is a mirror element used in place of the roof prism, and forms a right angle with each other.
It has two mirror surfaces. Light that has entered the prism from the object side is emitted to the roof reflecting mirror. This light is reflected by the roof reflecting mirror, returns to the prism, is reflected by one surface of the prism, and travels to the eyepiece side.

It is preferable that one surface of the prism for reflecting the light returning from the roof reflecting mirror to the eyepiece side is constituted by a vapor deposition surface. The light returning from the Dach reflector is
Since it is necessary to reflect all the light to the eyepiece side, it is necessary to consider a critical angle in order to realize such reflection on a normal prism surface, and the degree of freedom of the prism shape is limited. However, by adopting a configuration in which this reflection is performed on the deposition surface, it is not necessary to secure a critical angle, and the freedom of the prism shape is not limited.

In the present invention, the roof reflecting mirror may be integrally formed with the prism holder holding the prism, or the roof reflecting mirror and the prism may be independently mounted in the binocular body. The former case is advantageous in terms of cost because the number of parts is reduced. On the other hand, in the latter case, the optical axis can be adjusted by adjusting the relative position between the roof reflecting mirror and the prism.

In addition, depending on the method of arranging the prisms,
In some cases, the auxiliary prism has fewer transmission / reflection shared surfaces than the roof prism. In this case, the auxiliary prism is constituted by a reflecting mirror instead of the roof prism.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a flat-shaped binocular according to an embodiment of the present invention;
FIGS. 1A and 1B show the appearance of flat binoculars to which the present invention is applied, wherein FIG. 1A shows the interpupillary state, FIG. 1B shows the interpupillary state, and FIG. FIG. 4 shows a view from the eyepiece side in an expanded state. FIG. 2 is an exploded view of the binoculars of FIG. FIG.
(a) shows the left and right covers 3, 2 removed from the binoculars of FIG. 1, and FIG. 4 shows the internal focus adjustment mechanism by further removing the upper base plate 6 from the state of FIG. 3 (a).

First, the overall structure of the binoculars will be described. The fixed body 4 shown in the exploded view of FIG.
0, a right optical system such as an eyepiece unit including a prism holder 15 and a prism 16, an eyepiece unit including an eyepiece frame 17 and an eyepiece moving frame 18, and a focus adjustment unit shown in FIG. . The right cover 2 is fixed to the fixed body 4.

On the opposite side of the right optical system with respect to the focus adjustment unit, a left movable lens barrel composed of a movable body 5, a left objective lens frame 10 ', prism units 15' and 16 ', an eyepiece unit 20, and the like. Is located. A left cover 3 is fixed to the left movable lens barrel using screws or the like.

FIG. 5A is an enlarged view of the lower base plate 7 shown in FIG. 2 and the guide 8 formed integrally therewith. The left movable lens barrel is slidably fitted to the guide 8, and is guided by the guide 8 to slide. As the guide means for the left movable lens barrel, in addition to the one integrally formed, as shown in FIGS. Alternatively, it is also conceivable to use one fixed in direct contact. However, the integrally formed guide 8 is not shown in FIG.
Compared with the configuration of (b), the thick portion surrounding the shaft is unnecessary, which is advantageous for thinning (Y <Z). Further, compared to the configuration of FIG. 5C, the cost is reduced by the reduction in the number of components due to the integration.

As shown in FIG. 3A, an upper base plate 6 and a lower base plate 7 extending toward the movable body 5 are fixed to the upper and lower surfaces of the fixed body 4, and the left and right sides are interposed between them. A movable lens barrel is sandwiched. A leaf spring 110 is arranged on the upper surface of the left movable lens barrel. The leaf spring 110 urges the left movable lens barrel toward the lower base plate 7 and forms an interpupillary distance adjusting mechanism together with the guide 8.

As an example of the prior art, there is known one in which two guides are provided near an eyepiece and near an objective lens. However, in the present invention, in order to achieve a reduction in the thickness of the binoculars, only one guide is used, and the guide 8 is used as the field masks 19, 1 that can narrow the light flux most.
It was located near 9 '. In the conventional configuration in which two guides are provided, the guide provided on the object side is intended to stop rotation. In the present invention, such a rotation stop slides the movable body 5 on the lower base plate 7. Achieved by contact. With such a configuration, not only can the binoculars be made thinner, but also the degree of freedom in designing the optical system is increased.

The operation of the focus adjustment mechanism is performed by holding the lens frames 10, 10 'for holding the objective lenses of the right fixed lens barrel and the left movable lens barrel.
Is moved in the optical axis direction. The structure for this focus adjustment is as follows. That is,
As shown in FIG. 4, a pin 10a is formed at the tip of the arm of the right objective lens frame 10, and this pin 10a is slidably fitted into the long hole 34a of the right adjustment plate 34. Similarly, a pin 10a 'is also formed at the tip of the arm of the left objective lens frame 10', and is slidably fitted in the long hole 33a of the left adjustment plate 33.

When the focus adjustment knob 31 is turned, the integrated focus adjustment shaft 30 also rotates, and the nut 32 linearly moves in the optical axis direction. The pins 10a and 10a 'of the objective lens frames 10 and 10' are fitted to the left and right adjustment plates 33 and 34 fixed to the nut 32, respectively.
10, 10 'move in the direction of the optical axis, and focus adjustment is performed.

FIG. 6 shows a diopter adjustment mechanism. The diopter adjustment operation is performed by rotating a diopter adjustment knob 24 pivotally supported on the side surface of the right cover 2 so as to be perpendicular to the optical axis. That is, the eyepiece frame 17 is screwed to the fixed body 4, and the eyepiece moving frame 18 integrally supporting the lenses G2, G3, and G4 constituting the eyepiece lens group 41 in the eyepiece frame 17.
Are mounted so as to be movable in the optical axis direction (see FIG. 7).

When the diopter adjustment knob 24 is turned, the eyepiece moving frame 18 is rotated by a rotation-linear motion conversion mechanism (not shown) using an eccentric shaft or the like.
Performs a linear motion. The outermost lens G1 is a single-sided lens having a flat outer surface. This lens G
1 is fixed to an eyepiece frame 17, and an internal lens group G2,
It plays a role in protecting G3 and G4.

As shown in FIG. 7, lenses G2, G3,
G4 is oval, while lens G1 is circular. The reason is that the lenses G2, G3, G4
This is because the upper and lower ends of the lens G1 need to be cut in order to incorporate the lens G1 into the inside of the moving frame 18, but since the lens G1 is fixed to the outside of the moving frame 18, it is not necessary to make such a cut. Further, since the lens G1 is located at a position where the light beam is converged, a smaller lens diameter may be used. In addition, since the lens G1 is located on the outermost side in the optical system, it is highly likely that the lens G1 will be damaged. Therefore, it is preferable to use a glass lens.

In the illustrated example, the mounting portion 100 has an oval shape in which the upper and lower portions of the wall are cut off for the circular lens G1. The total height of the eyepiece frame 17 can be reduced by the thickness of the cut peripheral wall of the mounting portion. Use of a circular lens also has advantages such as a reduction in lens component cost and a reduced possibility that the lens is mounted at an angle when the lens is assembled.

FIG. 8 shows an objective lens system, that is, FIG.
The right objective lens frame 10 shown in the exploded view of FIG. 1 and the lenses G5 and G6 attached thereto are shown. Also in the objective lens system, when the thickness of the binoculars is reduced, it is preferable that each lens is basically an oval shape in which the upper and lower parts of a circle are cut.
However, it is preferable to use a lens having a circular shape or a shape close to the circular shape in a range that does not hinder the thickness reduction, in the same manner as the lens G1 having a circular shape in the eyepiece lens system, in terms of cost reduction and improvement in accuracy. In the example shown in FIG. 8, the lens G6 has an oval shape, and the lens G5 placed at a position where the light beam is converged has a circular shape. Instead of the circular lens G5, it is also conceivable to use a lens having only one cut like G5 '. The lens G6
Protective glasses 14, 14 'held by glass holders 13, 13' are arranged outside (see FIG. 2). The protective glasses 14, 14 'play a role of preventing intrusion of dust and the like.

As shown in FIG. 3, on the upper surface of the upper base plate 6, a plurality of raised rails 25 extending perpendicular to the optical axis are provided in parallel with each other. Similarly, a plurality of rails 26 are provided on the lower surface of the lower base plate 7 in parallel with each other (FIG. 3B).
reference). The left cover 3 is guided by the upper and lower base plates 6 and 7 and slides in the horizontal direction. During the sliding, the left cover 3 is prevented from rattling in the vertical direction by the rails 25 and 26. Also, the front ends 6a, 7a and the rear ends 6b, 7b of the upper and lower base plates 6, 7 in the optical axis direction can prevent rattling in the optical axis direction when the left cover 3 slides. , And is in contact with the inner wall surface of the left cover 3 (see FIG. 3B).

As shown in FIG. 3 (c), a projection 3a extending parallel to the bottom wall 3b is formed on the inner peripheral surface of the left cover 3 at a position slightly higher than the bottom wall 3b. I have.
That is, the bottom wall 3b of the left cover 3 and the projection 3a
Is sandwiched from above and below. Therefore, even if the lower base plate 7 is formed of plastic, sufficient strength against an external load is ensured.

In the illustrated example, the lower base plate is sandwiched between the left cover bottom wall surface 3b and the projection 3a. However, the position of the projection 3a is changed to change the upper base plate 6 to the left cover upper wall surface. It is good also as composition which sandwiches with a projection. It is preferable that no external force acts on the movable lens barrel. Therefore, in the illustrated example in which the guide 8 is formed integrally with the lower base plate, it is better to adopt a configuration in which the upper base plate is sandwiched between the left and right. The parallelism of the optical axis can be stably maintained.

A concave portion 9 is formed on the upper surface of the upper base plate 6 (that is, the surface that is in sliding contact with the upper wall surface on the inner surface side of the left cover), and the elastic body 111 is disposed in the concave portion. When the left cover 3 slides, the elastic body 111 slides on the upper wall surface of the cover to prevent dust and the like from entering the binoculars from the gap between the left cover 3 and the upper base plate 6. Although not shown in the figure, an elastic body that acts in the same manner is also arranged on the back surface of the lower base plate 7.

In the illustrated example, the left cover 3 slides using the base plates 6 and 7 as a guide, and the left movable lens barrel slides using the guide 8 as a guide. Therefore, if the left cover 3 and the movable body 5 of the left movable lens barrel are firmly fixed to each other, they will be over-constrained. Therefore, as shown in FIG. 9, there is provided a flow structure in which a slight gap is provided between the left cover 3 and the movable body 5 to give backlash, or a spring 27 is interposed to allow play within a predetermined range. It is preferable to employ it.

In the flat binoculars in which the interpupillary distance is adjusted by sliding the main body in the lateral direction, the entire volume of the binoculars changes between the state in which the interpupillary distance is stored and the time when the interpupillary distance is widened. Means for concealing the space generated therebetween are required.
For this reason, as shown in FIG. 1, the left cover 3 is made larger than the right cover 2 and the larger left cover 3 is slid. That is, the space created between the two lens barrels after the left optical system moves is covered by the left cover 3.

The eyepiece has the following configuration in view of design restrictions and usability. That is, FIG.
As shown in (a) to (c), in the interpupillary state, the focus adjustment knob 31 is located substantially at the center with respect to the entire width of the binoculars, and when the interpupillary distance is increased, the adjustment knob 31 remains at the same position. , Only the left cover 3 slides.

At this time, the barrier 22 integrally attached to the left cover 3 covers the space after the movement of the left optical system. The barrier 22 is protected by the knob cover 21 and the upper and lower base plates 6 and 7 so that there is no problem even if an external force is applied directly. The knob cover 21 includes the left and right covers 3,
The left and right covers 3, 2 prevent the left and right covers 3, 2 from interfering with the nose when the user holds it. In addition, even if the left cover 3 is opened, the concave shape is configured to be maintained.

FIG. 10 schematically shows a general binocular optical system using a roof prism. The illustrated binocular optics is an objective lens for imaging an object at a focal position.
40, erect prism that erects the image inverted by the objective lens
116, composed of three elements of an eyepiece 41 for enlarging an image formed by the objective lens 40.

As a means for reducing the size and thickness of the entire binoculars, it is generally conceivable to use an objective lens having a small effective diameter, but in that case, the binoculars have a dark field of view. Therefore, as the objective lens 40,
A so-called oval lens in which the upper and lower portions of a circular lens are cut linearly is used. Correspondingly, the erecting prism 16 is also of a vertically thin type, and the eyepiece 41 is also an oval lens. As shown in FIG. 10, a Schmidt prism is used as an inversion optical system. The erecting prism 116 includes an auxiliary prism 116a and a roof prism 116b.
It is composed of The roof prism 116b has right-angle surfaces s and t.

FIG. 11 shows a traveling path of light in the erecting prism 116. FIG. 11 shows the erect prism 116 of FIG.
FIG. 4 is a view of the device viewed from above. The incident light from the objective lens 40 has a total of 3 on the p, q, and r surfaces of the auxiliary prism 116a.
After being reflected three times on the s-plane, the t-plane, and the u-plane of the roof prism 116b, the light exits to the eyepiece lens 41 side.

FIG. 14 shows an erect prism 120 having another shape.
The light traveling path in the above is shown. The incident light from the objective lens is twice in total on the p 'plane and the q' plane of the auxiliary prism 120a, and the v 'plane, the s' plane, and the t' plane of the roof prism 120b.
After being reflected four times in total on the surface and the u 'surface, the light exits to the eyepiece lens side.

When such a thin prism is used in order to reduce the thickness of the binoculars, it is necessary to increase the polishing accuracy of the prism, which considerably increases the cost. Therefore, it is conceivable to employ a reflecting mirror instead of the prism. However, the prism has an advantage that transmission and reflection can be performed on the same surface. Due to such advantages, the roof prism is considered to be a small binocular. In other words, if you replace all of the prisms with reflecting mirrors,
Even if cost reduction can be realized, thinning and miniaturization will be hindered. Therefore, one of the auxiliary prism and the roof prism, that is, the one that has little effect on the size even when replaced with a reflecting mirror, is replaced with a reflecting mirror.

That is, the roof prism and the auxiliary prism are compared, and the prism having the smaller number of transmission / reflection sharing surfaces sharing transmission and reflection of light is replaced with a mirror. If the common surface is replaced with a mirror, a mirror for reflection must be formed avoiding a portion through which light is transmitted, so that the inversion optical system becomes large. Therefore, the figure
The erect prism shown in Fig. 11 represents the roof prism,
In the erecting prism shown in FIG. 14, the auxiliary prism is replaced with a mirror.

Next, with reference to FIGS. 12 (a) and 12 (b), a configuration in which the roof prism is replaced by a reflecting mirror will be described.

This reversing optical system includes an auxiliary prism 16a,
And a roof mirror 102 used in place of the roof prism. The Dach mirror 102 is composed of two flat mirrors 90
The roof prism 116b operates in the same manner as the right-angled surfaces s and t of the roof prism 116b in the inverting optical system. That is, the light that enters this reversing optical system is
Following the same path as described in 11, the object advances from the object side to the eyepiece side. Plane mirror 1 on p-plane of auxiliary prism
The flat mirror 101 reflects the light reflected from the roof mirror toward the eyepiece side.

FIGS. 13A and 13B each show a specific configuration.

In the example shown in FIG. 13A, the roof mirror 1 is mounted on the prism holder 103 holding the auxiliary prism.
02 are integrally formed. By fixing the auxiliary prism 16a to the prism holder 103, a reversing optical system is configured.

In the example shown in FIG. 13 (b), a prism holder 105 and a mirror holder 104 formed of different members are employed. The prism holder 105 is formed by integrally forming a holding portion for holding the auxiliary prism 16a and the plane mirror 101. The mirror holder 104 includes the Dach mirror 102,
An attachment portion for attaching the roof mirror 102 to the binocular body is integrally formed.

The prism holder 105 to which the auxiliary prism 16a is fixed and the mirror holder 104 constitute an optical inversion system. These two members may be connected to each other by using an adhesive or the like, or may be individually formed. It may be attached to the binocular body. When individually mounted, the optical axis can be adjusted by moving only one (or both) and changing the relative position of both.

Instead of bonding the plane mirror 101 to the p-plane, a part of the p-plane may be formed as a vapor deposition plane. When a plane mirror or a deposition surface is not used, total reflection on the p-plane is required, and it is necessary to keep the critical angle. On the other hand, when a plane mirror or a vapor deposition surface is used, there is no such restriction, and there is an advantage that the degree of freedom in selecting the angle θ of the auxiliary prism is increased.

Next, with reference to FIGS. 15A and 15B, a configuration in which the auxiliary prism is replaced with a reflecting mirror will be described.

This reversing optical system comprises a roof prism 121 and a mirror 122 used in place of the auxiliary prism. Light entering from the object side is reflected by u 'of the roof prism 121.
The light is reflected by the surface and travels toward the mirror 122 (a part of the u ′ surface is an evaporation surface, and light is reflected on the evaporation surface). This light is further reflected by the mirror 122 and returns to the roof prism 121, and travels to the eyepiece side in the roof prism by following the same path as described with reference to FIG.

FIG. 15 (b) shows a specific configuration, in which the prism holder 12 integrally provided with the plane mirror 123a is shown.
3 is configured by bonding a roof prism 121 to the roof. In the example shown in the drawing, light from the eyepiece side is reflected on the vapor deposition surface while a part of the u 'surface is used as a vapor deposition surface. However, as another configuration, a plane mirror is attached to a part of the u' surface. It is also conceivable to attach or use total reflection on the u 'plane.

Next, the optical axis adjustment will be described. The optical axes of the right lens barrel and the left lens barrel are adjusted by adjusting the position of the prism block. In the binoculars of the present invention, the prism block in the left movable lens barrel is not adjustable, and the prism block in the right fixed lens barrel is adjusted by swinging in the direction perpendicular to the optical axis before attaching the right cover. This is because the right cover is attached to the right fixed lens barrel, so that the prism block disposed inside the right fixed lens barrel is not easily affected by the attachment, and therefore, after the optical axis adjustment, the external members such as the cover are removed. This is because the optical axis parallelism is not easily deviated even when attached to the right fixed lens barrel.

However, if the cover or the like is attached, the parallelism of the optical axis may be deviated, or the exterior member such as the cover may be replaced with the optical axis for the sake of assembly (for example, when it is desired to prevent dust from entering the optical system). If it is necessary to attach the lens before the adjustment, it is conceivable to adopt a configuration in which the eyepiece 1 shown in FIG. 1C is removed and the optical axis can be adjusted from the eyepiece side.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating flat and thin binoculars.

FIG. 2 is an exploded view of the binoculars of FIG.

3 is a perspective view showing a state in which left and right covers are removed from the binoculars of FIG. 1, a cross-sectional view of a sliding portion of the binoculars, and a perspective view of a left cover.

FIG. 4 further removes the upper base plate from the state of FIG.
It is a perspective view which shows a focus adjustment mechanism.

FIG. 5 is a perspective view illustrating a guide portion formed on a lower base plate of the binoculars.

FIG. 6 is a sectional view showing an eyepiece group;

FIG. 7 is an exploded perspective view of the eyepiece group of FIG. 6;

FIG. 8 is a perspective view showing an objective lens group.

FIG. 9 is a sectional view showing an example of a fixed state of the left movable lens barrel and the left cover.

FIG. 10 is a perspective view showing a general optical system used in an optical device.

FIG. 11 is a plan view illustrating a traveling path of light when the erect prism of FIG. 10 is viewed from above.

FIG. 12 is an explanatory diagram showing a configuration of a reversing optical system according to one embodiment of the present invention.

FIG. 13 is a perspective view illustrating a specific configuration of the reversing optical system of FIG. 12;

FIG. 14 is a plan view illustrating a traveling path of light when an erecting prism different from FIG. 10 is viewed from above.

FIG. 15 is a diagram showing a configuration of a reversal optical system according to another embodiment of the present invention, and a specific example thereof.

[Explanation of symbols]

 1 Eyepiece 2 Right cover 3 Left cover 3a Projection 3b Bottom wall 4 Fixed body 5 Movable body 6 Upper base plate 7 Lower base plate 8 Guide 9 Concave part 10 Objective lens frame 11 Guide shaft 12 Detent shaft 13 Glass holder 14 Protective glass 15 Prism holder 16 Prism 16a Auxiliary prism 17 Eyepiece frame 18 Eyepiece moving frame 19 Field mask 20 Eyepiece unit 21 Knob cover 22 Barrier 24 Diopter adjustment knob 25, 26 Rail 27 Spring 30 Focus adjustment axis 31 Focus adjustment knob 32 Nut 33 Left adjustment plate 34 Right adjustment Plate 40 Objective lens 41 Eyepiece 100 Mounting part 101 Flat mirror 102 Dach mirror 103 Prism holder 104 Mirror holder 105 Prism holder 110 Leaf spring 111 Elastic body 116 Erect prism 116a Auxiliary prism 116b Dach prism 120a Auxiliary prism 120b Dach prism 121 Dach prism 122 Reflecting mirror 123 Prism holder

Claims (8)

[Claims] 1. A roof reflecting mirror (1) which is arranged opposite to each other.
02) and a prism (16a), and the light entering the prism (16a) from the objective side
It is emitted to 2), and further this light is reflected by the roof reflecting mirror (102), returns to the prism (16a), is reflected by one surface of the prism (16a), and travels to the eyepiece side. Inverted optical system. 2. The one surface of a prism (16a) for reflecting light returning from the roof reflecting mirror (102) to an eyepiece side, wherein the one surface is constituted by a vapor deposition surface.
The inverting optical system as described. 3. The roof reflecting mirror (102) includes a prism (16a).
3. The reversing optical system according to claim 1, wherein the reversing optical system is formed integrally with a prism holder (103) for holding the optical system. 4. The reversing optical system according to claim 1, wherein the roof reflecting mirror (102) and the prism (16a) are independently mounted in the binocular body. 5. Reflecting mirrors (122) arranged opposite to each other.
And a roof prism (121), in which light entering from the object side is reflected by one surface of the roof prism (121), further reflected by a reflecting mirror (122), and then to the roof prism (121). And an inverting optical system characterized by invading and proceeding to the eyepiece side. 6. The inverting optical system according to claim 5, wherein said one surface of said roof prism (121) for reflecting light entering from said object side to a reflecting mirror is constituted by a vapor deposition surface. 7. The roof mirror (122), wherein the reflecting mirror (122) is a roof prism (121).
7. The reversing optical system according to claim 5, wherein the reversing optical system is formed integrally with a prism holder (123) for holding the lens. 8. The reversing optical system according to claim 5, wherein the reflecting mirror (122) and the roof prism (121) are independently mounted in the binocular body.