JP2001133843A - Finder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a finder device capable of attaining the miniaturization of the device and contributing to the reduction of a manufacturing cost by providing a simply constituted means for guiding external light into the device without installing a lighting window. SOLUTION: As for the finder device with an objective optical system for forming an object image, a reversion optical system for making the object image formed by the objective optical system an erected normal image, and an eyepiece optical system for enlarging the object image and observing the enlarged object image, the finder device is provided with a transmissible reflection surface 56a arranged in the reversion optical system and a display means (display panel 42) for displaying the image formed by the objective optical system and visual field information in the superposed state so that the image can be observed through the eyepiece optical system through the transmissible reflection surface, and the display means is provided with a lighting part for taking natural light into the device, a display part for displaying the visual field information with the natural light taken by the lighting part, and a light guiding part for guiding the luminous flux taken by the lighting part to the display part, and the lighting part, the display part and the light guiding part are formed into one body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder device, and more particularly to a finder device for confirming and observing a visual field range including a desired subject image in a camera for photographing and the like.

[0002]

2. Description of the Related Art Heretofore, a so-called real image type of construction has been adopted in which a subject image formed by an objective optical system is converted into an erected image via an inverting optical system, and this image can be magnified and observed by an eyepiece optical system. As for the finder device, for example,
Various proposals have been made in JP-A-82634 / JP-A-10-307315 and the like, and are generally put into practical use.

The means disclosed in Japanese Utility Model Laid-Open Publication No. 6-82634 is a real image type finder device, in which display means for displaying field information at a position conjugate with a subject image formed by an objective optical system is provided. The display of the visual field information and the subject image by the objective optical system are superimposed via the half mirror so that they can be simultaneously observed by the eyepiece optical system. In this case, in order to allow the display by the display means to be observed by the eyepiece optical system, the apparatus is provided with a so-called lighting window through which a light beam from the outside of the apparatus is introduced into the apparatus.

The finder device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 10-307315 defines various fields related to photography, for example, a field of view to be a photography range by superimposing on a subject image formed by a finder optical system and observable. A means for displaying visual field information for displaying visual field information for displaying visual field frame information and a setting and an operation state of the camera in a form that can be visually identified is arranged separately from the finder optical system, so-called daylighting type. Examples of things are shown.

[0005]

However, in the conventional finder device disclosed in Japanese Utility Model Application Laid-Open No. 6-82634 and Japanese Patent Application Laid-Open No. 10-307315 described above, which is provided with a lighting window, There is a problem that the finder device itself becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to convert an object image formed by an objective optical system into an erect image via an inverting optical system. In a so-called real image type finder device which can be magnified and observed by an eyepiece optical system, natural light (external light) from the outside of the device can be realized with a simpler configuration without providing a large lighting window on the exterior of the device. The object of the present invention is to provide a finder device which can reduce the size of the device and contribute to the reduction of the manufacturing cost by providing means for incorporating the device inside.

[0007]

In order to achieve the above object, a finder device according to a first aspect of the present invention includes an objective optical system for forming an image of a subject and a subject image formed by the objective optical system. In a finder device having an inverting optical system for forming a normal image and an eyepiece optical system for enlarging and observing a subject image, a transparent reflecting surface provided in the inverting optical system, Display means for allowing observation by the eyepiece optical system in a form in which an image formed by the objective optical system and visual field information are superimposed via a reflecting surface, and the display means A lighting unit that takes in natural light from the inside of the apparatus, a display unit that receives the natural light collected by the lighting unit and displays visual field information, and a light guide unit that guides the light flux collected by the lighting unit to the display unit. When Characterized in that it is integrally formed.

According to a second aspect of the present invention, in the finder device according to the first aspect, there is further provided illumination means comprising an electric light emitting element, and the display means receives illumination light from the illumination means. It has a second lighting part.

According to a third aspect of the present invention, in the finder device according to the first aspect, the display section displays a distance measuring frame indicating at least a distance measuring position within a range of a finder field of view. It is characterized by.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. The finder device of the present invention is used for, for example, a camera for taking a photograph or the like, and is used for confirming a range of a visual field of a desired photographing range or confirming an observed image of a subject when performing a photograph or the like. belongs to. The embodiment described below shows an example in which the finder device of the present invention is applied to a camera.

FIGS. 1 and 2 show a camera to which a finder device according to a first embodiment of the present invention is applied. FIG. 1 is a perspective view showing an appearance of the camera, and FIG. FIG. 3 is a block diagram of a main part showing a configuration.

The main body and various components of the camera 1 of this embodiment are an exterior member formed by a front cover 1a and a rear cover 1b, and a barrier member 1c slidably disposed on the front surface of the front cover. Covered by

Various operation members and the like are arranged on the peripheral surface of the exterior member of the camera 1, and a predetermined position is set such that some of the various components arranged inside are exposed to the outside. Are located in For example, on the upper surface of the camera 1, various setting operations such as a release button 32, which is an operation member operated when starting a photographing operation, a photographing mode, an internal clock setting, and a strobe function setting are performed. Operating members such as a plurality of mode switching operation buttons 35a as operating members and a liquid crystal display (LCD) or the like so that the photographing mode information, date and time information, camera status information, etc. can be visually recognized. And an information display member 36a for displaying in a predetermined form such as a light guide means for taking in natural light into the finder device and guiding it to a predetermined surface. A display plate 42 and the like, which are display means for displaying the image so that the image can be observed by being superimposed on the image, are provided. The details of the display plate 42 will be described later (see FIGS. 4 to 9).

On the front surface of the camera 1, a front surface of a strobe light emitting portion 27 (see FIG. 2) is protected at a predetermined position near one upper edge, and a flash from the light emitting portion 27 is directed forward of the camera 1. A strobe light emission window 27a for irradiating a predetermined range including the subject is arranged.

A substantially central portion of the front surface of the camera 1 is provided on a light-exposed surface of a roll-shaped film 5 (see FIG. 2) disposed inside the camera 1 so as to transmit a light beam of a subject contributing to photography. An imaging optical system 21a for forming a subject image on the lens barrel 21b is disposed while being held by a lens barrel 21b.

A light projecting lens 1 constituting a part of a distance measuring device that contributes to a distance measuring operation is provided at a predetermined position near the upper edge of the exterior member of the camera 1 at the periphery of the photographing optical system 21a.
1 and a light-receiving lens 12 (detailed configuration of the distance measuring device will be described later), and an objective optical system which constitutes a part of the finder device of the present embodiment (a finder optical system in the present finder device will be described later. Finder window 41a for covering and protecting the front surface of the camera. Further, at a predetermined position near the upper edge on one end side on the back side of the camera 1, a zoom lever 43 and the like which are operated when performing the zooming operation of the photographing optical system 21a are arranged.

Then, the barrier member 1c is connected to the front cover 1a.
Are slidably disposed in the direction of arrow X shown in FIG. That is, when the barrier member 1c moves in a predetermined direction, the main members arranged on the front surface of the camera 1, such as the photographing optical system 21a and the lens barrel 21b, the finder window 41a, the light projecting lens 11, and the light receiving lens 12 And the like, in which the front surface is covered and protected by the barrier member 1c,
The front surfaces of these members are exposed to the outside and change to an open state in which a photographing operation can be performed. The state shown in FIG. 1 represents the open state of the barrier member 1c.

As shown in FIG. 2, the camera 1 includes various components provided inside the main body, various electric circuits, and the like. In the main body of the camera 1 according to the present embodiment, there is provided a control circuit 30 for controlling the entire camera 1 which is formed by a CPU or the like.
Various circuits and the like are electrically connected to the control circuit 30 directly or indirectly through various constituent circuits and the like.

That is, the control circuit 30 includes a DX code input circuit 2 for reading, for example, film information such as film ISO sensitivity from a DX code of the film cartridge 3 in which the film 5 is wound and stored, A film feeding circuit 4 for controlling the driving of a film feeding mechanism 7 via a film feeding motor 6 for feeding the film 5 sent from the film feeding device, and a film feeding operation by the film feeding circuit 4 during the film feeding operation. 5, a film feed state detecting circuit 24 for detecting the perforation and the like and detecting the amount of movement thereof, and a distance measuring means and a distance measuring device for measuring the distance to the main subject 9 located substantially at the center of the photographing screen. And a photometric unit formed by a photometric sensor 15 and the like for measuring the luminance of the field including the object 9 and the like. And ambient light measurement circuit 14, a shutter control circuit 16 which controls the driving of the plunger 18 is a drive mechanism for causing the opening and closing operation of the sector shutter 17 consisting of diaphragm-shutter blade for opening and closing the exposure opening portion,
A sector position detection switch 19 for detecting the position of the sector shutter 17, and a focus adjustment lens of the photographing optical system 21a held inside the lens barrel 21b based on subject distance information and the like obtained by the distance measurement circuit 8. A motor drive circuit 20 for driving and controlling a drive motor 22 that moves along the optical axis direction via a focus drive mechanism 23; a lens movement state detection circuit 25 for detecting a movement state of the focus adjustment lens from a reference position; Umbrella and Xenon (Xe)
A strobe circuit 2 for controlling light emission and charging of a strobe device including a strobe light emitting section 27 formed by a tube or the like.
6 and the first state responding to the operation state of the release button 32 arranged on the upper surface of the camera 1, that is, the first-stage ON state (half-pressed state) or the second-stage ON state (full-press state). (1st.) Release detection switch 33 and second
(2nd.) A release detection switch 34, a mode setting circuit 35 for setting an operation mode of the camera 1 in response to an operation of a plurality of mode switching operation buttons 35a (see FIG. 1),
A display circuit 36 for driving and controlling the information display member 36a (see FIG. 1), and a display circuit 37 in the finder for controlling display (for example, display of photographing information and the like) in the field of view of the finder device are directly or indirectly provided. Electrically connected.

When the film cartridge 3 is loaded in the camera 1, the DX code input circuit 2 converts a DX code or the like provided at a predetermined position on the outer peripheral surface of the cartridge 3 by, for example, printing or the like into a film ISO. It reads film information such as sensitivity.

The distance measuring circuit 8 constitutes a part of the distance measuring device as described above. The distance measuring device includes a light emitting element 10 such as a light emitting diode (LED) that is a light emitting means and emits an infrared light beam or the like, and emits light from the light emitting element 10 in a predetermined direction and a predetermined range. A light projecting lens 11, a light receiving lens 12 for collecting reflected signal light reflected by the subject 9 from a light beam emitted from the light projecting element 10, and a light detecting element (PS) serving as a light amount signal unit.
D) and the like.

The operation of the distance measuring device will be briefly described as follows. That is, the distance measurement circuit 8 performs the above-described 1st. In response to an ON signal from the release detection switch 33, that is, an instruction signal for instructing the start of the distance measuring operation, the light emitting element 10 is driven to emit light, and the infrared light beam from the light emitting element 10 is transmitted through the light emitting lens 11. The light is projected toward the subject 9. The reflected signal light is condensed via the light receiving lens 12 and is received by the light receiving element 13 via this. As a result, based on the light receiving position of the light receiving element 13, the distance measuring circuit 8
Is calculated, and the distance to the desired subject is calculated. The data (digital value) such as the subject distance information obtained here is transmitted to the control circuit 30, and a predetermined automatic focus adjustment operation is performed.

The shutter control circuit 16 controls the driving of the plunger 18 as described above, and
7 is a circuit for performing the opening / closing operation of 7. The sector shutter 17 is an aperture / shutter having a triangular aperture characteristic.

That is, the sector shutter 17 is mounted on the plunger 1.
8 is controlled by the shutter control circuit 16, the sector opening (exposure opening) is gradually opened by an ON signal from the plunger 18, while the sector opening (exposure opening) is opened by the OFF signal from the plunger 18. The exposure opening is rapidly closed.
In this case, the start time of the opening operation of the sector opening (exposure opening) is detected by the sector position detection switch 19.

The operation mode of the camera set by the mode setting circuit 35 includes, for example, a flash photography mode. In this strobe shooting mode, for example, an auto strobe mode in which a strobe light is automatically emitted or a strobe light is prohibited according to a shooting condition such as a subject brightness, or a strobe light emission is performed regardless of shooting conditions such as a subject brightness. A strobe off mode forcibly forbidden, a daylight synchro mode for arbitrarily emitting strobe light according to a shooting condition such as a backlight condition or a desired subject in a shade in the outdoors in the daytime, and the like. The operation modes of the camera are not limited to this, and a film feeding operation mode for performing a continuous shooting operation, a self-timer mode and an interval timer for automatically generating a release signal after a predetermined time has elapsed. There are various things such as modes.

Next, a detailed configuration of the finder device of the present embodiment will be described below. FIG. 3, FIG. 4, FIG.
6 and 7 are diagrams showing a main configuration of the finder device of the present embodiment. 3 is a developed view of the optical system in which the finder optical system of the present finder device is developed, and conceptually shows a path of a light beam incident on the finder optical system. 3A shows a state where the finder optical system is set at the shortest focus position on the wide angle side, FIG. 3B shows a state where the finder optical system is set at the standard focus position, and FIG. Each state shows that the finder optical system is set at the longest focal position on the telephoto side.

FIG. 4, FIG. 5, and FIG. 6 are member arrangement views mainly showing members constituting a finder optical system out of the constituent members of the present finder apparatus. 4 is a perspective view, FIG. 5 is a top view, and FIG. 6 is a side view. 4 and 5.
FIG. 6 is an optical path diagram showing a configuration of the finder optical system and also showing an optical path of a light beam incident on the finder optical system. In FIG. 5, reference symbol A indicates the image forming position of the subject image by the objective optical system (see FIG. 3). FIG. 7 is an enlarged side sectional view of a main part of the camera (FIG. 1) to which the present finder device is applied, and the arrangement of display means in the finder device of the present embodiment and the inside of the camera to which the present finder device is applied. It is a figure showing arrangement of a display means.

As shown in FIG. 3, the finder optical system in the finder device of the present embodiment includes an objective optical system formed by a plurality of objective lens groups and a part of the inversion optical system, and another part of the inversion optical system. And an eyepiece optical system formed by the eyepiece lens 57.

The objective lens group is for forming a subject image by receiving a light beam from the subject, and is constituted by a plurality of optical elements (lenses). That is, a first lens 51 fixed at a predetermined position on the main body of the camera 1,
The second lens 52 and the third lens 53 are provided so as to be movable in the optical axis direction and move to predetermined positions in conjunction with the zooming operation of the photographing optical system 21a.

The reversing optical system is provided to turn the subject image formed by the objective lens group into an erect erect image, and is formed by three prisms. That is, the first prism 54 and the second prism 55 forming a part of the objective optical system, and the third prism 55 forming a part of the eyepiece optical system.
It is formed by the prism 56. The first prism 54 has a first reflecting surface 54a (see FIG. 6) having a reflecting surface formed by aluminum evaporation or the like. In addition, the second prism 55 includes a second reflecting surface 55a and a third reflecting surface 55b which are two total reflecting surfaces.
The prism 56 has one transmissive reflection surface (a so-called half mirror) 56a formed therein.

The objective optical system includes an objective lens group including the above-described first, second, and third lenses 51, 52, and 53, and first and second prisms 54 and 55 of the inverting optical system. ing.

On the other hand, the eyepiece optical system is provided for forming an enlarged image suitable for observing the image of the subject which has been turned into an erected image by the inverting optical system. A third prism 56 and an eyepiece (a so-called loupe) 57 are provided.

As shown in FIG. 3, the second prism 55
The third prism 56 and the third prism 56 are arranged so as to have a predetermined interval therebetween, that is, an interval indicated by reference numerals D1 and D2 in FIG. Note that the subject image formed by the objective optical system is set so as to form an image in a focused state at a position indicated by reference numeral A in FIG. Therefore,
In the following description, the position indicated by reference numeral A in FIG. 3 is referred to as an image forming position. Each optical element (a lens, a prism, etc.) constituting each optical system is arranged as shown in FIGS. 4, 5, and 6.

On the other hand, this finder device has a fourth prism 5 for adjusting the traveling direction of a light beam as shown in FIGS. 4, 5, and 6, in addition to an optical system for forming an observation image.
8 are provided. The fourth prism 58 is attached to a surface of the third prism 56 outside the surface on which the transmissive reflection surface 56a is provided, whereby the fourth prism 58 is provided integrally with the third prism 56. I have.

In the vicinity of the fourth prism 58, a photometric sensor 15 constituting a part of photometric means at a predetermined position, natural light is introduced into the inside of the apparatus, and at the same time, finder visual field information is superimposed on the subject image for observation. There is provided a display plate 42 which is a display means for displaying so as to obtain it.

The photometric sensor 15 is located on the optical path of the light beam that passes through the transmissive reflection surface 56a of the third prism 56 and travels straight, and the light receiving surface faces the condenser lens 58a of the fourth prism 58. At a predetermined position.

The display plate 42 is an extension of the optical axis (optical path) of the light beam that travels toward the eyepiece 57 after being reflected by the transmissive reflection surface 56a of the third prism 56. It is arranged at a predetermined position opposite to the side where the eyepiece 57 is arranged with the four prisms 58 interposed therebetween. The position where the display plate 42 is provided is set so as to be substantially optically equivalent to the image forming position of the subject image formed by the objective optical system.

FIGS. 8 and 9 are enlarged views showing only the display plate of the present finder device. FIG. 8 is a side view and FIG. 9 is a front view. The display plate 42 is formed of, for example, a transparent plate-shaped member. In addition, as shown in FIG. 8, a cross section on the upper side is formed with a lighting portion having a predetermined shape such as a substantially semicircular shape, that is, a shape in which external light is more easily condensed. A part of the lighting unit is shown in FIGS.
As shown in the figure, the finder device is provided so as to be exposed to the outside of the camera 1 to which the finder device is applied.

The display surface of the display plate 42, that is, the fourth
A plurality of display portions (42c and 42d) are formed in a predetermined form at predetermined positions on the surface facing the prism 58 and indicated by reference numeral 42e in FIG. 8, as shown in FIG.
It is desirable that each of the plurality of display units is formed by a light diffusion surface. That is, the display units 42c and 42
By forming d by the light diffusing surface, the light illuminating the plurality of display portions is diffused, and illumination with a larger amount of light is performed, and the display to be represented by this can be more clearly observed. Become.

The display units 42c and 42d of this predetermined form
Is provided to display in a form that can be visually recognized within the range of the finder visual field and to display the finder visual field information by a predetermined means. For example, a symbol, a character, a pictogram as shown in FIG. Display board 4 in a predetermined form such as
2 is formed by drilling a part.

In FIG. 9, reference numeral 42c denotes information relating to the range of the field of view of the finder, and is an example of display to indicate an index of parallax correction. Reference numeral 42d is an example of a display representing a distance measurement frame (a so-called target mark) which is located substantially at the center of the finder visual field and serves as an index of a distance measurement position when performing a distance measurement operation or a photometry operation. The display form of the display unit is not limited to these display examples, and various other forms can be naturally considered.

Then, external light as indicated by an arrow H in FIG. 8 is easily reflected inside the display plate 42 to illuminate the display portions 42c and 42d provided on the predetermined surface 42e. Therefore, the display plate 42 is formed using a glass material having a high refractive index, and the display portions 42c and 42d
The surface opposite to the surface provided with, that is, the surface 42f located near the front surface of the camera 1 is subjected to a predetermined coating process to have a low refractive index, for example, or a reflective surface is formed. As a result, a light guide portion for guiding the incident light beam in a predetermined direction is formed.

If the surface of the display panel 42 is subjected to aluminum evaporation or coating to reflect natural light taken in from outside the camera body inside the display panel 42, more light can be displayed on the display unit. 42c and 42d.

As described above, the display plate 42 takes in natural light from the outside of the camera body, and also serves as a light guiding means for guiding the collected light beam to the display unit side, whereby the display units 42c and 42d function. It is illuminated. Therefore, a predetermined display is provided by the display portions 42c and 42d of the display plate 42. In this way, the display plate 42 also serves as an illumination unit that illuminates the display unit.

The display plate 42 is disposed such that the upper end portion serving as a lighting portion is exposed outside the camera 1 as described above. In this case, the display plate 42 is
As shown in FIG. 5, a lighting part is fixed so as to protrude upward at a predetermined position of a finder lid 41b covering an upper surface side of the finder device main body 41, and a tip of the lighting part is further connected to an exterior part of the camera 1. It is arranged to protrude.

That is, at a predetermined position of the front cover 1a,
As can be seen from FIG. 1, a cutout 1d having substantially the same shape as the cross section of the display plate 42 is provided. By mounting the rear cover 1b from the rear surface with the display plate 42 fitted in the notch 1d, the display plate 42 is held so as to be sandwiched between the two covers 1a and 1b.

In this case, a fitting gap or the like may occur between the display plate 42 and the covers 1a and 1b. Therefore, in order to prevent unnecessary light flux entering the inside of the finder device from such a gap or the like and to secure a light-tight state, a light shielding member 41c shown in FIG.
Is disposed in a gap between the exterior member 41 of the finder device and the front cover 1a and the rear cover 1b, which are exterior members of the camera 1. As the light-shielding member 41c, a general light-shielding member such as a malt plane or a telempe cloth is used.

With such a configuration, the display portions 42c and 42d of the display plate 42 of the present finder device are always illuminated by the natural light flux which is taken in from the outside by its own lighting portion and enters through the light guide portion. It has become.

FIG. 10 is a view showing a display state in the range of the finder visual field 70 of the present finder device.
In this finder device, as shown in FIG. 10, the displays 70c and 70 corresponding to the display units 42c and 42d respectively.
d is in a state of being always displayed by the illumination light of the natural light flux.

On the other hand, the fourth prism which enters the third prism 56 from the second prism 55 side, emits a light beam which is not reflected by the transmissive reflection surface 56a of the third prism 56 but passes through it and travels straight. A condensing lens 58a is integrally provided on the light path of the same light beam on the exit surface 58b of the light source 58. The condensing lens 58a is set so as to converge the incident light beam and emit the light beam in a predetermined direction, that is, toward the light receiving surface of the photometric sensor 15.

As described above, the fourth prism 58 guides the light flux transmitted without being reflected by the transmissive reflection surface 56a of the third prism 56 to the photometric sensor 15, and at the same time, the display plate 42
And the luminous flux from the first prism 56
It serves to guide the light beam transmitted through 6a toward the eyepiece lens 57. Therefore, the fourth prism 58 having such a role does not directly contribute to the function for observing the subject image or the like. From this,
The fourth prism 58 is not shown in the developed view of the finder optical system shown in FIG.

The image forming position of the object image formed by the objective optical system (the position indicated by reference numeral A in FIG. 3) is set as follows. In the finder device of the present embodiment, as described above, the second prism 55 (first optical element) is disposed closer to the objective optical system than the imaging position A of the subject image, and the third prism 55 (first optical element) 2) is disposed closer to the eyepiece optical system than the imaging position A of the subject image.

In this case, for example, the focal length of the eyepiece optical system is set to f (mm), and the exit surface (55k; see FIGS. 4 and 5) of the second prism 55 (first optical element) and the image of the subject are formed. The distance from the image position A is D1 (mm; see FIG. 3).
When the distance between the incident surface of the third prism 56 (second optical element) and the imaging position A of the subject image is D2 (mm; see FIG. 3), D1> f ＾ 2/250 ([＾ ] Represents a power) and the imaging position A is set so as to satisfy D2> f ＾ 2/250 ([＾] represents a power). This indicates the position of the exit surface of the second prism 55 or the entrance surface of the third prism 56 with respect to the imaging position of the subject image observed by the eyepiece 57. According to the above-described conditional expression, the observation diopter at the image formation position is
This indicates that the observation diopters at the positions of the exit surface of the prism 55 and the entrance surface of the third prism 56 are separated by 4 diopters (1 / m). That is, the surfaces of the second prism 55 and the third prism 56 on the image forming position side are separated from the image forming position of the subject image by a sufficient distance, so that the surfaces of the second prism 55 and the third prism 56 adhere to the surface. The conditions are set to prevent the observed dust and the like from being observed.

That is, the human eye can observe the object even if the diopter is slightly deviated within a certain diopter range. This prevents dust and the like adhering to the surfaces of the prism 55 and the third prism 56 from being observed.
In addition, the amount of deviation of the diopter is 3 to 4 in actual use.
A diopter (1 / m) distance is enough,
It is more effective if the distance is about 6 diopters (1 / m).

Although the focal length f of the eyepiece optical system is usually about 20 to 30 mm in the normal case, the focal length f is set shorter than that in the normal case so as to be about 10 to 20 mm. Then, the distances D1 and D2 can be set small. Accordingly, by reducing the size of the finder device and increasing the magnification by the eyepiece optical system, the finder magnification can be set to a large value without increasing the size of the objective optical system.

From the above points, in this embodiment, the focal length of the eyepiece optical system is set to about 15 mm. In the present embodiment, in order to make it possible to shorten the focal length of the eyepiece optical system, the reflecting surface of the inverting optical system is provided with three surfaces ( First reflection surface 54a
The second reflecting surface 55a and the third reflecting surface 55b) are arranged, and one surface (transmissive reflecting surface 56a) is arranged on the eyepiece optical system side.

Further, as described above, the display plate 42 needs to be disposed at a position optically equivalent to the image forming position of the subject image. However, the configuration of such an inversion optical system and the focus of the eyepiece optical system are required. By devising the distance, the eyepiece optical system and the display plate 42 can be arranged close to each other, and thus the size of the device itself can be reduced.

The operation of the finder device according to the present embodiment thus configured will be described below. First, the first
The light beam from the subject incident from the lens 51 is incident on the first prism 54 via the second lens 52 and the third lens 53, and is reflected on the first reflecting surface 54a of the first prism.
Thereby, the optical path of the same light beam is bent at an angle of approximately 90 degrees, and is directed upward in FIG. 4 to enter the second prism 55.

The light beam incident on the second prism 55 is reflected by the second reflection surface 55a and the third reflection surface 55b of the second prism 55, respectively, so that the optical path is changed and the second prism 55 Exit surface 55k
After being emitted from the light source (see FIGS. 4 and 5) and passing through the field frame opening 61k of the field frame member 61 and being restricted to a predetermined range, the light beam enters the third prism 56.

A part of the light beam incident on the third prism 56 is reflected by the transmissive reflection surface 56a of the third prism 56, and its optical path is bent at an angle of approximately 90 degrees and guided to the eyepiece lens 57 side. Therefore, a state in which the image of the subject can be observed by the eyepiece lens 57 is obtained.

Another part of the light beam incident on the third prism 56 passes through the transmissive reflection surface 56a of the third prism 56, and is guided to the photometric sensor 15 via the condenser lens 58a. As a result, a state in which a predetermined photometric operation can be performed is achieved.

In addition to the incident light beam from the first lens 51 described above, a natural light beam also enters the interior of the finder device via the light guide portion of the display plate 42 from the lighting portion of the display plate 42. This light flux is applied to the display panel 4 as shown in FIGS.
After passing through the second prism 58, the light enters the fourth prism 58, passes through the transmissive reflection surface 56 a of the third prism 56, and proceeds further straight to be guided to the eyepiece 57. Therefore, in the eyepiece 57, the display of the display plate 42 formed by the incident light beam from the display plate 42, that is, the display units 42c and 42d, is added to the subject image formed by the incident light beam from the first prism 54 as described above. (In this embodiment, parallax correction mark 70)
A finder image in which the c and the target mark 70d) are superimposed on the subject image is observed.

As described above, according to the first embodiment, a natural light (external light) beam outside the finder device is taken into the inside, and the collected light beam is sent to the predetermined display unit 4.
By providing the display panel 42 as a means for illuminating the display unit 2c and 42d and thereby illuminating the display unit, it is simpler without providing a daylighting window or the like which is a cause of enlargement in the conventional finder device. With a simple configuration, natural light can be collected and the display unit can be illuminated. Therefore,
The miniaturization of the finder device and the reduction of the manufacturing cost can be easily realized.

Further, since only natural light is used without providing electric lighting means or the like, no power is required for performing a predetermined display in the viewfinder field. Therefore, it is possible to contribute to the suppression of power consumption of the finder device and the camera 1 or the like to which the finder device is applied.

In the first embodiment, the display section of the display means (display panel 42) is illuminated using only natural light. However, with this means, when the surrounding environment is very dark, such as at night, the amount of illumination by natural light may be insufficient, and the display on the display means may not be clearly observed. Can be

To cope with such a case, that is, a case where the amount of illumination by natural light is insufficient, the following example can be considered. FIGS. 11 and 12 are enlarged views showing a display unit and a second illumination unit for illuminating the display unit with an electric light emitting element in the finder device according to the second embodiment of the present invention. Front view,
FIG. 12 is a side sectional view. The finder device of the present embodiment will be described below with reference to FIGS.

The basic configuration of the finder device of this embodiment is substantially the same as that of the above-described first embodiment.
The only difference is that the shape of the display means is slightly different as shown in FIG. 12, and the second illuminating means for illuminating the display means with an electric light emitting element is provided accordingly. Therefore, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and detailed description and illustration thereof are omitted.

The display plate 42 which is the display means, the light guide means and the illumination means in the finder device of this embodiment.
In A, as shown in FIG. 11, a plurality of concave portions 42Af serving as light condensing means are arranged at predetermined positions on an end (lower end in FIG. 11) opposite to the end on which the lighting portion is formed. ing.
The cross section of the plurality of concave portions 42Af is formed so as to be substantially semicircular toward the inside of the display plate 42A. The reason why such a shape is adopted is that more illumination light flux from a second illumination means (LED 62a) described later can be collected.

On the other hand, a predetermined electric board 62A is provided below the concave portion 42Af of the display plate 42A and on the bottom side of the finder device. The electric board 62A includes
A plurality of electric light emitting elements, ie, light emitting diodes (LEDs) 62a, serving as second lighting means are mounted.

That is, the plurality of recesses 42Af of the display panel 42A are arranged so as to correspond to the plurality of LEDs 62a, respectively.
A is covered by the plurality of recesses 42Af.

The light emission timing, light emission speed, light emission time and the like of the LEDs 62a can be arbitrarily controlled by the control circuit 30 via the display circuit 37 in the finder (see FIG. 2).

A predetermined switch member (not shown) for generating a command signal for controlling the start or stop of the light emitting operation by the LED 62a is also mounted at a predetermined position on the electric board 62A. The switch member is configured to be linked with a predetermined operation member (not shown) provided on an exterior portion of the camera 1 to which the present finder device is applied, for example, and by operating the operation member arbitrarily. The light emission of the LED 62a can be controlled via the display circuit 37 in the finder. Other configurations are exactly the same as those of the first embodiment.

In the finder device of the present embodiment configured as described above, when the finder device is used at night or when the surrounding environment is dark, the predetermined switch described above, that is, the display circuit 37 in the finder is used. Then, a predetermined switch (not shown) for giving a command signal to start the lighting operation of the LED 62a as the second lighting means is turned on. The command signal generated thereby controls the LED 62a via the finder display circuit 37 to emit light for a predetermined time. Then, the illumination light of the LED 62a is collected by the concave portion 42Af of the display plate 42A, enters the inside of the display plate 42, and illuminates the display portions 42c and 42d via the light guide. Thus, the subject image and the display units 42c and 42d are displayed in the viewfinder visual field observed by the eyepiece 57.
Displays 70c and 70d formed by (see FIG. 10)
Are observed in a form in which is superimposed.

As described above, according to the second embodiment, the display portions 42c and 42d of the display plate 42 are normally illuminated by collecting natural light to display the display formed in the viewfinder field. On the other hand, when the surrounding environment is dark, the display portions 42c and 42d of the display plate 42 are illuminated by the illumination light of the second illumination means arbitrarily by an electric light emitting element. Even under an environment where the amount of illumination light is insufficient, the display on the display means can always be clearly observed.

[0075]

As described above, according to the present invention, a subject image formed by the objective optical system can be converted into an erected image via the reversing optical system, which can be magnified and observed by the eyepiece optical system. In a so-called real image type finder device with such a configuration, without providing a large lighting window on the exterior of the device,
It is possible to provide a finder device which has a simpler configuration and incorporates means for taking in natural light (external light) from the outside of the device into the inside, whereby the device can be miniaturized and the manufacturing cost can be reduced. .

[Brief description of the drawings]

FIG. 1 is an exemplary perspective view showing the appearance of a camera to which a finder device according to a first embodiment of the present invention is applied;

FIG. 2 is a main block diagram showing the internal configuration of the camera shown in FIG. 1;

FIG. 3 is a diagram illustrating a main configuration of the finder device according to the first embodiment of the present invention, and is an expanded view of an optical system in which the finder optical system in the finder device is developed.

FIGS. 4A and 4B are a perspective view and an optical path diagram showing an arrangement of members by mainly taking out members constituting a finder optical system among constituent members in the finder device of FIG. 3;

FIGS. 5A and 5B are a top view and an optical path diagram showing an arrangement of members mainly taken out of members constituting a finder optical system among constituent members in the finder device of FIG. 3;

FIGS. 6A and 6B are a side view and an optical path diagram showing an arrangement of members taken out mainly of members constituting a finder optical system among constituent members in the finder device of FIG. 3;

7 is an enlarged side cross-sectional view of a main part of the camera of FIG. 1, showing an arrangement of a display plate in the finder device of FIG. 3 and an arrangement of a display plate inside the camera to which the present finder device is applied;

FIG. 8 is an enlarged side view showing only a display plate in the finder device of FIG. 3;

FIG. 9 is an enlarged front view showing only a display plate in the finder device of FIG. 3;

FIG. 10 is a view showing a display state in a range of a finder visual field of the finder device of FIG. 3;

FIG. 11 is an enlarged front view showing a display plate and a second illumination unit using an electric light emitting element in the finder device according to the second embodiment of the present invention.

FIG. 12 is an enlarged sectional side view showing a display plate and a second illuminating means for illuminating the display plate in a finder device according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Camera 15 ... Photometric sensor 21a ... Photographing optical system 21b ... Lens barrel 30 ... Control circuit (control means) 32 ... Release button 37 ... Viewfinder display circuit 41a ... Viewfinder window 42 / 42A ... Display panel (display means / light guide means / illumination means) 42c / 42d display part 42Af recess (light collecting means) 51 first lens (objective optical system) 52 second lens (objective) Optical system) 53 Third lens (objective optical system) 54 First prism (objective optical system / reversal optical system; first)
54a first reflecting surface 55 second prism (objective optical system / inverting optical system; second optical element)
55a Second reflecting surface 55b Third reflecting surface 56 Third prism (reversing optical system / eyepiece optical system) 56a Transparent reflecting surface 57 Eyepiece lens (eyepiece optical system) 58 Fourth prism 58a Condenser lens 62A Electric board (second lighting means) 62a Light emitting diode (LED; second lighting means)

Continuation of the front page (72) Inventor Yukihiko Sugita 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industrial Co., Ltd. F-term (reference) 2H018 AA04 BA02 BE02 2H102 AA41 AA44 BB03 CA32

Claims (3)

[Claims] 1. An objective optical system for forming a subject image,
In a finder device having an inversion optical system for turning an object image formed by the objective optical system into an erect erect image and an eyepiece optical system for enlarging the object image and observing the image, the inversion optical system And an image formed by the objective optical system and field-of-view information can be observed by the eyepiece optical system in a superimposed manner by passing through the transparent reflective surface provided in the camera. Display means, comprising: a lighting section for taking in natural light from above into the device; a display section for receiving natural light taken by the lighting section to display visual field information; and A finder device, wherein a light guide unit for guiding the collected light beam to the display unit is integrally formed. 2. The apparatus according to claim 1, further comprising: lighting means comprising an electric light emitting element, wherein said display means has a second lighting part for lighting illumination light from said lighting means. The finder device as described. 3. The finder device according to claim 1, wherein the display unit displays at least a distance measurement frame indicating a distance measurement position within a range of a finder field of view.