JPH0274935A - Focusing display device provided on optical apparatus such as camera or the like - Google Patents

Abstract

PURPOSE:To constitute the title device so that an object to be photographed or a part of the object to be photographed whose focus is adjusted can be confirmed at a glance by peeping through a finder by showing a display of a display mark in an image part of the object to be photographed whose focus is matched in an image of the object to be photographed which is formed in the finder. CONSTITUTION:Each optical display mark 29a-29e corresponding to plural measuring parts is provided in a finder, and also, a control circuit 28 for bringing the display marks 29a-29e corresponding to the distance measuring parts which are brought to a focus from adjusted distance information, to display variation selectively is provided. That is, when a photographic lens is moved in accordance with the adjusted distance information, the optical display marks 29a-29e are brought to display variation and a matching state of the focus is displayed. As for the display marks 29a-29e, in plural parts of an object to be photographed whose distance is measured, that which corresponds to a distance measuring part in which the focus is matched is selected and brought to display variation. Also, this finder is constituted so that a virtual image 33 of the object to be photographed and a virtual image 38 of the display mark become an optically conjugate position against an eyepiece 32. In such a way, the display mark which is overlapped on an image of the object to be photographed and brought to display variation can be confirmed visually.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a focus display device used in optical equipment equipped with an automatic distance measuring mechanism, such as a camera, a camera, an electronic camera, a video camera, and the like.

``Prior Art'' As a camera having an automatic distance measuring mechanism, one that detects the distance to a subject using a multi-range measuring method is known.

Fig. 5 is a simplified diagram for explaining the multi-distance measuring method of this type of camera, in which 11 is the distance measuring device installed in the camera, A is the photographing area, ○, ~O9 are the subjects, and D~D. , indicates the distance to each subject.

The distance measuring device 11 projects infrared light in the form of a beam. This infrared light beam 11 is sequentially projected onto areas A1, A2, . The infrared light reflected at each of the points 0 to 05 is received by a light receiving device provided at a camera position different from the light projecting position, and the distance is measured.

That is, the distances D1 to D to each subject are determined by triangulation using the light projection position, subject position, and light receiving position.
It is configured to calculate.

The distances D□ to D5 calculated in this way are the distances D□ to D5 of each subject O! ~05 is calculated to find the most appropriate adjustment ratio 51D, and the photographing lens is moved according to this adjustment distance.

Various methods have been proposed for calculating the adjusted distance, but to give an example, the measured distance D1
〜D5, those that are infinite and those that are closest to this are removed, and the distance jiiD is calculated from the remaining distance measurements.
M a x and D min are searched and calculated using the following formula.

D= (Dmax+2Dmin)/3 The optical image of the photographic lens moved by this adjustment distance is the distance Dmax
, Dmin, the imaging state is almost the same for the subject.

Figure 6 shows the viewfinder field of view of this type of camera.
Reference numeral 2 denotes a field frame indicating a photographing area, and 13 an optical focusing operation completion indicator consisting of an LED or the like.

In such a finder, the photographing range is determined by the field frame 12, and completion of the focusing operation is confirmed by lighting the display 13.

``Problem that Hamoe is trying to solve'' As with the conventional example described above, in the case of a structure in which the lighting of the focus operation completion indicator 13 is confirmed along with the subject image within the field of view of the finder, it becomes complicated to detect all subjects. It is not necessarily a desirable method to do so.

Further, the above-mentioned focusing operation completion indicator 13 is a simple lighting display using an optical display element, and therefore does not match the image of focusing.

Furthermore, with the above-mentioned conventional finder, the subject to be photographed can only be observed within the viewfinder field frame 12, and it is unclear where the subject appears in the viewfinder field frame 12 to be in focus. If this was not done, there was a problem in that it would not be possible to determine which part of the subject was in focus.

The present invention has been developed in view of the above-mentioned problems.In a camera that determines the amount of movement of the photographic lens by performing multiple distance measurements on the subject, the present invention can be used to superimpose the part of the subject that is in focus on the subject image, and to check the focus in the viewfinder. The purpose is to develop display devices.

"Means for Solving the Problem" In order to achieve the above-mentioned object, the present invention measures distances at multiple locations on a subject, calculates an adjustment distance from distance measurement information for each of the multiple locations, and calculates the adjustment distance from the distance measurement information for each of the multiple locations. In an optical device such as a camera equipped with an automatic distance measuring mechanism that moves the photographic lens according to A control circuit is provided that selectively changes the display of the display mark corresponding to the focused distance measurement point based on information.

A focus display device is proposed, which is characterized by having a configuration in which a focused distance measurement point is superimposed on a subject image and can be confirmed in a finder.

"Effect" When the photographic lens is moved according to the adjustment distance information,
Optical indicator marks change in display to indicate focus alignment.

Among the plurality of distance-measured points on the subject, the display mark corresponding to the distance-measuring point where the focus matches is selected and the display changes.

Further, the display mark whose display has changed in this way is displayed superimposed on the subject image formed in the finder.

``Example'' Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an example of the circuit configuration of the multi-range-finding mechanism and the focus display, and 21 is a block diagram showing each area A8 to A8 in FIG.
A light emitting device that emits an infrared beam to A, 22
is a drive circuit for sequentially causing each of the light sources 21a to 21e of the light emitting device W21 to emit light.

This drive circuit 22 outputs an identification signal S2□ which indicates which light source among the light sources 21a to 21e is emitting light.

23 is a light receiving element such as a PSD (position sensing device), which is used to detect objects 01 to 0.0 shown in FIG. receives the infrared light reflected by the The light-receiving element 23 and the light-emitting device i21 are arranged at a predetermined interval and are configured to detect the distances of the objects 0□ to O9 by triangulation.

24 is the light receiving output S2 of the light receiving element 23. and identification signal Szx
Therefore, the distance from each subject 00 to o5 fa D L
” This is an arithmetic circuit that calculates Ds.

25 is a memory having addresses determined according to areas A, ~A, and distance #D calculated by the arithmetic circuit 24;
The information of z - D s is input and stored according to each address.

26 is the formula explained as an example in the conventional example, D= (Dma
This is a calculation circuit that calculates the adjustment distance by x+2Dmin)/3.

The photographic lens is moved by the calculation output 52G of the calculation circuit 26.

27 is the calculation output SAG which shows the practical range of focus Δd and Δd2 determined by the photographing lens aperture, film resolution, etc. for the subject part where the focus matches.
This is a search circuit that calculates the search signal S2ff and outputs the search signal S2ff. This search signal S2□ is D+Δd1≧Do≧D−
It is determined as Δd2 and output as information regarding the distance range D0 to the subject location where the focus matches.

When the search signal S2□ is input to the memory 25, the distance range is selected among the stored information regarding the distances D to D. or the calculated distance r
The one closest to aD is searched.

When the distance information is retrieved, the address information where the distance information is stored, that is, the area information An, is sent as the output signal Szs of the memory 25.

28 is a drive circuit (or decoder), 29 is a display board, and these form a focus display.

The drive circuit 28 inputs the output signal SZS, decodes the contents of the area information An, and supplies power to the display mark on the display board 29 corresponding to the decoded area.

The display board 29 includes display marks 29a to 29e formed of an LCD (liquid crystal member), and the display of any of the display marks changes according to the area decoded by the drive circuit 28.

FIG. 2 is an enlarged view of the above-mentioned display board 29. As shown in the figure, frame-shaped display marks 29a to 29e are formed side by side using an LCD, and the parts other than the display marks 29a to 29e are opaque. be.

The display board 29 formed in this manner has the drive times Fk! t2
8, only the display mark that is selectively supplied with power becomes transparent and the display changes.

FIG. 3 is an optical system diagram showing an example in which the display plate 29 described above is arranged in a camera finder. Reference numeral 31 denotes an objective lens made of a concave lens, and 32 an eyepiece made of a convex lens, through which a virtual image 33 formed in front of the objective lens 31 is viewed. Reference numeral 34 is a semi-transparent mirror that allows viewing by combining light in the Y direction and light in the X direction.

The above-mentioned display board 29 is arranged behind the diffuser plate 35, and when any of the display marks changes to be transparent, the frame-shaped light of the display mark is sent to the total reflection mirror 36.

The total reflection mirror 36 changes the optical path in the X direction.

The convex lens 37 provided in the optical path in the X direction forms an image of the display mark (changed in display) on the display board 29 as a virtual image 38 in front of the diffuser plate 3S, and this virtual image 38 corresponds to the clear viewing distance of the eyepiece 32. It is set up so that

That is, this finder is constructed so that the subject virtual image 33 and the display mark virtual image 38 are at optically conjugate positions with respect to the eyepiece lens 32. As a result, it is possible to visually recognize the display mark whose display has changed so as to be superimposed on the subject image.

As described above, in this embodiment, the infrared light beam sequentially projected from the light emitting device 21 to each area A□ to A5↓ is reflected by the objects 01 to ○, and this reflected light is received by the light receiving element 23. Ru.

When the light reception output S23 is input to the arithmetic circuit 24, the distance D1 to D to the subjects 01 to 05 in each area is calculated by this circuit 24, and the information of this distance 11iD to D5 is stored in the memory 25 for each area. is memorized.

Further, the calculation circuit 26 calculates the adjustment distance according to the calculated distances D1 to D5, and moves the photographing lens based on the calculation output 82G.

On the other hand, when this calculation output SAG occurs, the search circuit 27
calculates the distance range D0 to the subject where the focus matches,
The stored contents of the memory 25 are searched by the search signal 527.

The memory 25 outputs, as area information, the address information in which the distance information included in the distance range D0 or the distance information closest to the calculated distance 1iD is stored by the above search.

The drive circuit 28 inputs the output signal S2 of the memory 25, decodes the area corresponding to the searched distance information from the output signal S2I, and selects one of the display marks 29a to 29e according to the decoded area. , power the selected display mark.

For example, if the retrieved distance information is Dl, the output signal S is is a signal related to area A1, so the drive circuit 28 selects the display mark 29a, supplies power to the display mark 29a, and changes the display.

Similarly, when distance information D2 is searched, display mark 29
b is selected and supplied with power, and similarly distance information 1, D
4. When D is searched, display marks 29c, 29
d and 29e change in display.

In this way, the mark corresponding to the area where the subject or subject location is in focus changes to a transparent state, so in the finder, in addition to the entire subject image in shooting area A, 5 images are selected as described above. The displayed mark images overlap and form an image, and as a result, it is possible to confirm which part of the subject is in focus. In addition, the distance range is . If there are multiple areas, the display marks corresponding to the multiple locations change in display.

Although one embodiment has been described above, the present invention can be implemented as follows.

(1) In addition to the above-mentioned multi-distance measurement method, distances D1 to Ds can be calculated by emitting ultrasonic waves or light and measuring the time it takes for them to hit the subject and return, or to capture the subject using a lens. It is also possible to use means such as calculating the distances D1 to D5 by image formation analysis.

(2) In addition to the LCD, an electro-optical element such as an electrochromic device may be used for the display board 29, or a frame shape may be formed on the film and only the necessary areas may be locally illuminated with a plurality of electric lights from the back side. Means such as the following can be used.

(3) In the above embodiment, D+Δd1≧D0≧D−Δd
Memory 2 according to the distance range D11 defined by 2.
5 and select display marks 29a to 29e, but the adjustment ratio tJi that the calculation output S□ of the calculation circuit 26 has
Search the memory 25 for the distance JItDx closest to D and 5
Display mark 29a according to the output signal of this memory 25
29e may be selected.

(4) When carrying out the present invention, the number of display marks 29a to 29e corresponding to areas A1 to A5 is not limited to five, and the number of display marks 29a to 29e can be increased or decreased or the shape of the marks can be changed arbitrarily. In addition to the one shown in the figure, the finder may be of an albata type, a real image type, or the like, and furthermore, this finder may be an electric device that images the subject on a cathode ray tube.

(5) In addition, when the focus display device of the present invention is implemented in a real image finder, for example, when it is incorporated into a finder of an eye reflex camera, it can be changed from transparent to ground glass by changing the voltage application state. A focusing glass is constructed using a light-scattering liquid crystal plate, and the display of a plurality of display marks provided on the liquid crystal plate is changed.

Specifically, as shown in FIG. 4, quadrilateral display marks 40a to 40e that become transparent by supplying power to the surface of the liquid crystal panel 40 are formed side by side, and these display marks 4
0a to 40e are selectively supplied with power by the driver circuit 28 to which the output signal Szs of the memory 25 is input, as in the above embodiment, and the object location in focus is confirmed from the mark position where the transparency has changed.

"Effects of the Invention" As described above, the focus display device of the present invention displays a display mark in the part of the subject image that is in focus among the subject images formed in the viewfinder, so that multiple locations on the subject can be seen. Even with an optical device that measures distance and moves a photographic lens, it is possible to confirm at a glance which subject or part of the subject is in focus by looking through the viewfinder.

In addition, if the display mark is composed of an optical element such as an LCD, it can be determined that focus is aligned when the display mark appears, and that the focus is not aligned when it does not appear, which has the effect of not complicating the observation of the viewfinder field of view. There is.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, FIG. 1 is a block diagram showing an example of the circuit configuration of an automatic ranging mechanism and a focus indicator, and FIG. 3 is an optical system diagram of a finder equipped with the focus indicator, FIG. 4 is a simplified diagram showing an example of display marks on the finder of a single-lens reflex camera, and FIG. FIG. 6 shows a conventional example, FIG. 5 is a simplified diagram for explaining the multi-distance measuring method, and FIG. 6 is a simplified diagram showing the viewfinder field of view and a focus indicator. 21... Light emitting device 22... Drive circuit 23... Light receiving element 24... Arithmetic circuit 25... Memory 26... Arithmetic circuit 27... Search circuit 28... ...Drive circuit 29...Display plates 29a to 29e...Display marks Figure 3 Figure 5 Procedures Amendment Book July 11, 1999. Director General of the Japan Patent Office Yoshi 1) Takeshi Moon 1, Indication of the case Patent Application No. 226468 of 1988 2, Name of the invention Focusing display device 3 for an optical device such as a camera, relationship with the correction person case Patent Applicant: 2-9-13 Nakameguro, Meguro-ku, Tokyo (230) Representative: Stanley Electric Co., Ltd.
Toru Shima 4, Agent Seven Central Building 902-5, 3-11-4 Iidabashi, Chiyoda-ku, Tokyo Date of amendment order Contents of voluntary amendment (1) Detailed explanation of the invention on page 3, line 8 of the specification In the column of , D = (Dmax + 20m1 n) / 3 is written as 1 / D = (1 / Dmax + 1 /
Correct as Dmin)/2. (2) In the Detailed Description of the Invention column on page 7, line 7 to line 8 of the specification, D= (Dmax+2Dmin)/3 is replaced with 1/D-(1/Dmax+1/Dmi Correct it as n)/2.

Claims (1)

[Claims] In an optical device such as a camera that is equipped with an automatic distance measurement mechanism that measures distances at multiple locations on a subject, calculates an adjustment distance from distance measurement information for each of the multiple locations, and moves a photographing lens according to the adjustment distance information, the above-mentioned In addition to providing each optical display mark in the viewfinder corresponding to a plurality of distance measurement points, the control system selectively changes the display of the display mark corresponding to the distance measurement point that is in focus based on the above-mentioned adjustment distance information. What is claimed is: 1. A focus display device, characterized in that it is equipped with a circuit, and has a configuration in which a focused distance measurement point is superimposed on a subject image and can be confirmed in a finder.