JPS62259004A - Length measuring instrument - Google Patents

Abstract

PURPOSE:To record the size of an object without approaching to the object by computing and outputting the size of the object based on scale length data whose length on the expected focal plane of a lens is already known and lens data such photographic distance data. CONSTITUTION:The lens is put in focus on the object, a key switch 8b for scale selection is operated to select a scale (s), and the scale length data y' is read out of a ROM 8a and outputted to a length data output device 7 at the object position. Address signals at the point of time are outputted 3 from code plates 1 and 2 and photographic distance data D, focal plane data (f), and data H on the gap between principal points of the lens are read out of the ROM 4, outputted to a controller 6, and transferred to the device 7. The device 7 computes the actual size (y) at the object position based on the data D, (f), H, and y'. The length (y) and scale identification code (s) are inputted to a display device 9 and an imprinting device 10 under the control of the controller 6 to make a display in a finder respectively, thereby imprinting the data on a film surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a length measuring device for a camera that calculates the dimensions of a photographed subject, displays it in a finder, and also records it on a film surface.

[Conventional technology]

Conventionally, as a means of checking the dimensions of a photographed subject on a photo, a scale object such as a ruler, a ruler, a cigarette, a person, etc. is placed next to the subject, and the subject and scale object are placed on the same screen. It was imprinted inside.

In this way, it is not foolish to place a scale next to the subject, but if the scale is too thick or small compared to the subject, you can , the confirmation of the dimensions of the subject becomes inaccurate.

For this reason, data representing the shooting distance from the film surface to the subject, data representing the focal length of the shooting lens,
Data representing the scale corresponding to the length of the subject image on the film surface is calculated from data representing the principal point interval of the photographing lens, and the scale is imprinted on the film based on this calculated data. The applicant has already proposed an imprinting device (Japanese Unexamined Patent Publication No. 58-158
(See Publication No. 507).

[Problem to be Solved by the Invention 9] The conventional means for confirming the dimensions of an object described above all compare the dimensions of the object with a scale on the film surface, so the object dimensions are taken as approximate numbers. It was not possible to know the exact dimensions.

Further, depending on the subject, it may not be possible to get close to the subject, and in some cases it may not be possible to place an appropriate scale next to the subject, making it difficult to accurately know the dimensions of the subject.

[Failure to solve the problem]

In view of the above-mentioned points, this invention allows the photographer to know the size of a part or all of the subject intended by the photographer under all shooting conditions without getting close to the subject while performing normal photography. The object of the present invention is to provide a length measuring device for a camera that is capable of recording on film.

First, the basic principle for determining the object dimensions of this invention will be explained.

Fig. 2 is a diagram showing the state of image formation by the photographing lens, where the photographing distance is D, the focal length of the photographing lens is f, the distance between the principal points of the photographing lens is H1, the distance from the front focal position of the photographing lens to the subject. x1 Similarly, if the distance from the rear focal point position to the film plane is X', the length of the subject is y1, and the length of the subject image on the film plane is y', then between the above variables
: y'=x : f=f : x' ・
・・・・・・・・・・・・There is the relationship (1). However, as is clear from Fig. 2, x' = D -2f -) [-x -
・---...Since the relationship (2) holds true, from the equation on the right side of equation (1) and equation (2), if x ) f 琶宿■汀了)...
......The following relationship (3) holds true.

On the other hand, from the equation on the left side of equation (1), y' = (÷)y, and β = ÷, then y/ = βy
・・・・・・・・・・・・
It is expressed as (4). Here, β is also called the imaging magnification,
How much is the object of length y reduced (enlarged) on the film plane?
This indicates whether the image will be imprinted or not.

The following equation is obtained by rewriting equation (4) with respect to y)' = /
'Y' ・・・・・・・・・・・・
- As is clear from (5), when the photographer cannot approach the subject, such as when the subject is far away, the subject can be photographed by knowing the imaging magnification β and the size y' of the subject image on the film surface. The dimension y can be determined.

Then, the imaging magnification β is calculated from the above equation (3) as follows: β=÷=2
f/((D-2f-H)2 + J (D-2f-H
)2-4f2)......(6) That is, the imaging magnification β can be determined from the photographing distance, the focal length f of the photographing lens, and the principal point spacing data (2) of the photographing lens.

On the other hand, -eye reflex cameras generally have 7 lenses.
- Shinoya 1 Kakakuseibutryo r7nonn-7 A focus plate is placed at a fixed position (focus plane), and an image approximately equivalent to the subject image focused on the film plane is captured through the viewfinder eyepiece. It can be visually checked, and this is used to determine focus and composition. Therefore, if a scale with a known length S is placed on or near the focus plate in the finder optical system, and this corresponds to y' in equation (5) above, then
The object size y can be calculated from equation (5).

At this time, in order to measure the dimensions of an object of arbitrary size, if the scale length S is one type, it is necessary to change the imaging magnification β, which depends on the shooting distance to the object or the shooting distance. This means changing the focal length of the lens.

Changing the shooting distance is not appropriate because it may not be possible to get close to the subject, and it is desirable to change the focal length using a zoom lens. However, even when using a zoom lens, there may be cases where the angle of view or imaging magnification that matches the photographer's intentions cannot be obtained due to the combination of the size of the subject and the shooting distance. It is appropriate to provide a plurality of scales with different lengths and select a scale with an appropriate size, or to have a configuration in which the dimensions of the scale are variable.

Therefore, the sub-length device of the present invention includes a scale setting means for outputting scale length data whose length on the planned focal plane of the lens is known, and a scale setting means for outputting the scale length data outputted from the scale setting means. a display means for displaying a scale of known length; a lens data output means including photographing distance data, focal length data of the photographing lens, and principal point interval data of the photographing lens; and a photographing distance outputted from the lens data output means. data, the focal length data of the photographing lens, the principal point spacing data of the photographic lens, and the scale length data output from the scale setting means, calculate and output the object dimensions at the object position corresponding to the object image that matches the scale length. The present invention is characterized by comprising a length data output means at the subject position, and a recording means for recording the length data at the subject position.

[For production]

First, consider the angle of view of the subject image in the viewfinder, select an appropriate scale using the scale setting means, match the part of the subject you want to measure to this scale while zooming the photographic lens, and then focus. let

Through the above operations, the scale setting means outputs the scale length data y', and the lens data output means outputs the photographing distance data 1, the focal length data f1 of the photographing lens, and the principal point interval data I-1 of the photographing lens. be done.

Based on the above data, the length data output means at the subject position outputs the scale length displayed in the viewfinder according to equations (5) and (6) explained earlier, that is, the length of the part that matches this scale. Since the actual length of the subject at the subject position is calculated and output, this can be displayed and recorded by appropriate means.

〔Example〕

Next, embodiments of the invention will be described.

FIG. 1 shows the basic configuration of the portions related to the length measuring device in a camera incorporating the length measuring device of the present invention.

The configuration of the mass and lens section will be explained first. The lens section contains data specific to the exchangeable photographic lens necessary for automatic exposure control (hereinafter referred to as AE), automatic focus adjustment (hereinafter referred to as AF), and other camera sequence control on the camera body side. A read-only memory (hereinafter referred to as RON1) that stores distance data D, focal length data of the photographing lens f1, and principal point spacing data of the photographing lens.
4, a code plate 11 which generates a ROM address signal for reading out the above data corresponding to the movement of the lens by extension and zooming from the ROM; and a code plate 2 which generates a ROM address signal using the address signal generated by the code plate. An address specifying section 3 for specifying the specified address and a data output section 5 for transmitting data in the ROM read from the specified address to the camera body side are provided.

These code plates 1.2, address designation section 3, ROM
4 and the data output section 5 are provided in the lens barrel of an interchangeable lens (not shown).

Next, to explain the configuration of the camera body section, the camera body section includes a camera AE consisting of a microprocessor,
A control device 6 that performs AF and sequence control, and a display device 9 that displays a scale indicating the dimensions of the subject and length data of the subject, which will be explained later, are provided.

The camera back includes a length data output device 7 at the subject position consisting of a microprocessor, a scale setting device 8, and a device for imprinting the length data and scale output from the length data output device 7 onto the film. Including device 1o
is provided.

The scale setting device 8 has a plurality of scale identification codes S.
and a ROM that stores a plurality of scale length data y' corresponding to the scale lengths on the focal plane.
8a, a scale selection key switch 8b for the photographer to select a scale that matches his/her shooting intention, and a scale identification code S selected by the key switch 8b.
A selection unit 8 reads out scale length data y' from the RCM.
The selected scale identification code S is outputted to the display device 9 and the imprinting device 10, and the scale length data y' is outputted to the length data output device 7 at the subject position.

Next, the display device 9 will be explained. FIG. 3 shows an embodiment of the display device. This display device is installed in the viewfinder of the camera, and a plurality of scales 12 arranged in concentric circles in the center of the viewfinder are composed of liquid crystal, and the liquid crystal surface is arranged at the focal plane on the viewfinder. .

A plurality of scales I2 arranged concentrically are provided corresponding to the scale identification code SK selected by the scale setting device 8 described above, and are provided in correspondence with the scale identification code SK selected by the scale setting device 8 described above. When S is input to the drive circuit 14, only the liquid crystal scale 12 (for example, the portion with diameter d1) corresponding to the identification code S is driven and becomes visible.

The display device 9 is also provided with a data display section 15 that displays the length data y at the subject position calculated and outputted by the length data output device 7 at the subject position, and this is also similar to the scale described above. It is displayed at an appropriate position inside or outside the viewfinder screen using a display means such as a liquid crystal display.

FIG. 4 shows an example of the screen displayed on the finder and the display states of the scale 12 and data display section I5.

Note that the details of the configuration of the liquid crystal display panel and its driving circuit are well-known means, so the explanation will be omitted.

The imprinting device 1° incorporated in the camera back cover will be explained.

The imprinting device corresponds to the display device provided in the viewfinder, and includes a plurality of school imprinting sections configured by arranging light emitting elements such as LEDs with almost the same layout as the display device. There is a data imprinting section that imprints the length data at the subject position, which is constructed by arranging light-emitting elements such as LEDs. imprinted on the part.

When a scale is selected in the scale setting device 8, one of the scale imprinting areas is selected from a plurality of scale imprinting areas based on the scale identification code S that is output. The display element is driven to display the length data y at the subject position calculated and output by the length data output device 7 at the position.

The imprinting device is equipped with an imprint prohibition switch (not shown) that can be operated from the outside to prevent scale and length data from being imprinted on the film surface even if scale and length data are displayed in the viewfinder. It is configured.

Next, the operation will be explained. Here, it is assumed that the photographing lens is a zoom lens. While looking through the camera's viewfinder, the photographer focuses on part or all of the subject and performs a zooming operation to set the desired angle of view.

When the approximate composition is determined, the user operates the scale selection key switch 8b of the scale setting device 8 according to the size of the subject image in the finder to select the optimal scale.

Alternatively, you can look through the viewfinder, select a scale of appropriate size, zoom to select the angle of view so that the subject image matches the selected scale, and then focus. good. The flow of these operating procedures is shown in FIG.

In the scale setting device 8, scale length data y' representing the length of the subject on the focal plane corresponding to the scale identification code S input from the scale selection key switch 8b is read out from the RCM 8a, and the scale length data y' representing the length of the subject on the focal plane is read out from the RCM 8a. The length data is output to the length data output device 7.

On the other hand, from the lens section, according to the zooming operation of the photographic lens, the R
An address signal of photographing distance data D in the OM and an address signal of focal length data f of the photographing lens are output.

At the same time, an address signal of principal point interval data 1f of the photographic lens is output from a combination of signals output from code plates 1 and 2. In addition, camera AE,
An address signal of data unique to the photographing lens used for AF and other sequence control is also output.

Under a control signal output from the camera body side, photographing distance data D1 focal length data f1 principal point spacing data H are read out from the specified address of the ROM specified by the address signal, and other lens-specific data are also read out. The data is read out and output to the control device 6 on the camera body side.

The control device 6 transfers photographing distance data D1 focal length data f1 principal point spacing data I (data necessary to obtain object dimension data) to a length data output device at the object position on the camera back cover side.

The output device 7 outputs the three data D that have been transferred.
, f, I-1 and scale length data y' representing the length on the focal plane of the scale input from the scale setting device 8.
Based on this, first calculate the imaging magnification β using equation (6) explained earlier, and then calculate the actual size y at the subject position from this β and y′ using equation (5) also explained earlier. Calculate.

The length y at the subject position calculated by the output device 7 and the scale identification code S output from the scale setting device 8 are combined with the display device 9 under the control of the control device 6 that performs sequence control of the camera. is input into the imprinting device 10,
The display device 9 displays the scale and data y in the finder, and the imprint device 1O imprints the scale and data onto the film surface.

Regarding the display device 9 provided in the viewfinder and the imprint device 10 provided behind the film surface,
In addition to those shown in the above embodiments, several modifications are possible.

The second embodiment shown in FIG. 6 is a display device in which segments each composed of a liquid crystal or a light emitter such as an LED having a constant unit length U are arranged in the vertical and horizontal directions at the end of the viewfinder field of view. The imprint device is also an LE similar to this display device.
It is composed of light emitting body segment rows such as D. Since the configuration of other parts is the same as that shown in the first embodiment, the explanation will be omitted, and only the scale setting will be explained.

When the operator operates the scale selection key switch 8b of the scale setting device 8, a signal that determines the vertical and horizontal lengths and positions of the scale is output, and the signals are stored in the ROM as the starting and ending numbers of the vertical and horizontal segment rows. The scale length S, that is, the length y' of the scale on the focal plane, is output from the scale setting bag #8, which is set from the unit length U of the segment.

The calculation of the actual length dimension at the subject position from the length y' of the output scale on the focal plane, the display on the display device and the imprinting device, and the imprinting operation are performed in the same manner as in the first embodiment. .

The third embodiment shown in FIG. 7 is a display device in which segments composed of liquid crystals or light emitters such as LEDs with a fixed unit length U are arranged in a grid shape within the field of view of the finder. The position of the unit grid may be displayed on the screen.

Alternatively, the display may be a rectangle with different vertical and horizontal dimensions.

The imprinting device is also constructed with a similar segment arrangement.

To set the scale, as in the second embodiment, by operating the scale selection key switch 8b, a signal is output that determines the vertical and horizontal lengths and positions of the grid lines to be used as the scale.
The scale length S1, that is, the length y' of the scale on the focal plane, is output from the scale setting device 8, which is set from the identification numbers of the vertical and horizontal segments and the unit length U of the segment stored in the ROM.

Subsequent calculations, display, and recording operations are performed in the same manner as in the first embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, the photographing distance, the focal length of the photographing lens, and the principal point interval data of the photographing lens,
It is possible to calculate the actual dimensions of the subject at the subject position from the scale length data set within the viewfinder field of view, and it is possible to accurately measure the subject dimensions even when it is not possible to get close to the subject. .

When this length measuring device is incorporated into a camera, it is possible to record the actual size and scale of the subject on the film surface while taking pictures using almost the same procedure as a normal photographing procedure.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the basic configuration of the length measuring device of the present invention, Fig. 2 is an explanatory diagram of the principle of length measurement, Fig. 3 is a diagram showing an example of the display device in the finder, and Fig. 4 is the display. Fig. 5 is a flowchart showing the operating procedure for scale selection, Fig. 6 is a diagram showing a second example of the display device in the finder, and Fig. 7 is a diagram showing an example of the display device in the finder. It is a figure which shows the 3rd example of a display apparatus. ■, 2: Code board, 3 Near address specification section, 4: ROM1
5° data output unit, 6: control device, 7: length data output device at subject position, 8 scale setting device, 91 display device, 10: imprint device. Figure 2 Figure 3 Figure 5 Figure 6 Figure E300 000 0 Figure 7

Claims (4)

[Claims] (1) A scale setting means for outputting scale length data whose length on the planned focal plane of the lens is known; and a scale setting means for outputting scale length data having a known length on the planned focal plane of the lens; a display means for displaying a scale; a lens data output means including photographing distance data, focal length data of the photographing lens, and principal point spacing data of the photographing lens; and photographing distance data output from the lens data output means, photographing lens data, A length at the subject position that calculates and outputs the subject dimension at the subject position corresponding to the subject image that matches the scale length from the focal length data, the principal point interval data of the photographing lens, and the scale length data output from the scale setting means. 1. A length measuring device comprising: length data output means; and recording means for recording length data at the subject position. (2) The display means is equipped with a plurality of scales having different lengths, and selectively displays the scale based on the scale length data selected by the scale selection means and outputted from the scale setting means. A length measuring device according to scope 1. (3) Claim 1, characterized in that the display means includes means for displaying length data at the subject position.
2. The length measuring device according to item 1 or 2. (4) Claims 1 or 2 or 3, characterized in that the recording means is equipped with a recording means for recording length data at the subject position on a recording medium for recording the subject image. Length measuring device described in section.