JP3309415B2 - Constant magnification camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant magnification photographing apparatus for a camera which switches a photographing screen size.

[0002]

2. Description of the Related Art There is known a constant magnification photographing apparatus which automatically adjusts a zoom lens so that a main subject always has a constant size based on distance measurement information from a distance measuring apparatus. In this type of apparatus, for a film used by the camera, for example, 135 × 36 mm screen size, a proper main subject image size is specified and a photographing magnification is set.
The focal length of the zoom lens is adjusted based on the distance measurement information so that the photographing magnification becomes the same for each photographing.

Further, there is known a camera which switches a screen size by inserting a photographic screen frame in front of a film. For example, if a photograph is taken by inserting a screen frame for narrowing the vertical width of the photographing screen, and greatly enlarged at the time of printing in a laboratory, a photograph similar to that obtained by performing panoramic photographing can be obtained.

[0004]

However, when a camera for switching the screen size is provided with a constant magnification photographing device, the photographing magnification set by the constant magnification photographing device is set for a predetermined screen size of the film to be used. So that
If a new screen size is set using a screen frame smaller than the screen size, the main subject image may run out of the new screen size.

[0005] The FIG. 7 (a), illustrates this problem.
Now, the main subject, here the human image 2
It is assumed that the photographing magnification is set so that the size becomes as shown in the figure. When a panoramic image is taken by inserting a screen frame 3 for narrowing the top and bottom of the photographing screen 1 in front of the film in order to perform panoramic photographing, the head and chest of the human image 2 protrude from the screen frame 3. This is because the shooting magnification is set for the screen size of the original shooting screen 1. Even if the screen size is switched by inserting the screen frame 3, the size of the human image 2 does not change. The problem described above occurs.

An object of the present invention is to change the photographing magnification so that the relation between the photographed screen size and the size of the subject image when the photographed screen size is switched is substantially the same as the relationship before the switching. An object of the present invention is to provide a constant-magnification photographing device to be set.

[0007]

The present invention will be described with reference to FIG. 1 showing the configuration of an embodiment of the present invention. (1) The first aspect of the present invention relates to zoom lenses 10 and 11.
Driving means 1 for driving the zoom lenses 10 and 11
9, a distance measuring means 35 for detecting a photographing distance, and a driving lens 19 based on the photographing distance detected by the distance measuring means 35 so as to attain a preset photographing magnification.
The present invention is applied to a constant-magnification photographing apparatus for a camera having a control means 37 for adjusting the focal lengths of 0 and 11. Switching means 3 having a plurality of photographing screen sizes and switching between them;
3, a storage unit 37 for storing a photographing magnification set corresponding to each of a plurality of photographing screen sizes, and a moving range from the tele end to the wide end of the zoom lenses 10, 11 is divided into a plurality of focal length zones. And zoom lenses 10 and 11
Current zone detecting means 20 and 21 for detecting which focal length zone the current position of the zoom lens 1 is located in, and the zoom lens 1
A pulse generator 23 for outputting a pulse signal for each of the predetermined movement amounts of 0 and 11;
7, the focal length is calculated based on the photographing magnification corresponding to the photographing screen size after the switching and the photographing distance detected by the distance measuring unit 35, and the current position zone detecting unit 2 is calculated.
The driving unit 19 drives the zoom lenses 10 and 11 until the detection zone by 0 and 21 reaches the zone of the calculated focal length. When the zoom lens reaches the zone of the calculated focal length, the pulse signal of the pulse generation unit 23 is counted and calculated. The zoom lenses 10 and 11 are driven by the driving means 19 until the focal length reaches the predetermined value.
Drive. (2) According to the second aspect of the present invention, the photographing magnification is set for each photographing screen size so that the relationship between the photographing screen size and the subject image size becomes substantially the same before and after the photographing screen size is switched. It is like that.

[0008]

When the photographing screen size is switched by the switching means 33, the control means 103 corresponds to the switched photographing screen size stored in the storage means 37 based on the photographing distance detected by the distance measuring means 35. The driving means 19 adjusts the focal length of the zoom lenses 10 and 11 so that the obtained photographing magnification is obtained. At this time, first, the current position zone detecting means 2
The driving unit 19 drives the zoom lenses 10 and 11 until the detection zone by 0 and 21 reaches the zone of the calculated focal length. When the zoom lens reaches the zone of the calculated focal length, the pulse signal of the pulse generation unit 23 is counted and calculated. The zoom lenses 10 and 11 are driven by the driving means 19 until the focal length reaches the predetermined value.
Drive. In the means and means for solving the above-described problems, the drawings of the embodiments are used to facilitate understanding of the invention, but the present invention is not limited to the embodiments.

[0009]

FIG. 1 is a diagram showing a partial cross section of a camera according to an embodiment and a configuration of the apparatus. In the figure, reference numeral 10 denotes a first group lens, and 11 denotes a second group lens. Follower pins 12 and 13 are embedded in the lens chambers, respectively. These follower pins 12 and 13 are provided in a straight guide groove 14 fixed to the camera body and cam grooves 16 and 1 of a cam barrel 15.
7 through. The cam cylinder 15 has a gear portion 15 on its outer periphery.
a, and is rotationally driven by a motor 19 via a speed reduction mechanism 18.

FIG. 2 shows a state where the cam grooves 16 and 17 are developed in a plane. 2 (a) is, the first group lens 10 and 2
Follower pins 12 and 13 of group lens 11 are cam grooves 1
Moves along the 6,17, the first group lens 10 and second lens 11 is a wide-angle end (hereinafter, referred to as wide end) shows a state has been reached, FIG. 2 (b), the first group lens 10 and the two groups A state in which the lens 11 has similarly reached the telephoto end (hereinafter referred to as the telephoto end) is shown. 1st lens group 10 and 2nd lens group 1
1 is driven by a motor 19 and moves in the optical axis direction from the wide end to the tele end.

On the outer periphery of the cam barrel 15, the first lens group 10
And an encoder pattern 20 for detecting the amount of movement of the second lens group 11 is attached. FIG. 3 (a)
A state where the encoder pattern 20 is developed on a plane is shown. Reference numeral 21 denotes a slider which slides on four rows of conductors provided on the encoder pattern 20 and includes rows A, B, C and a ground Z. Encoder pattern 2
A value of 0 divides the movement range of the first lens group 10 and the second lens group 11 from the wide end to the tele end into eight zones, and sets a pattern according to the presence or absence of a conductor for each zone.
When the slider 21 slides on the encoder pattern 20, if there is a conductor in any of the rows A to C, the row and the ground row Z are short-circuited by the slider 21. That is, the signal corresponding to each zone shown in FIG. 3 (b) is sent to the control circuit 37, control circuit 37 can know the current position of the first lens unit 10 and the second group lens 11.

The position detection of the first lens group 10 and the second lens group 11 by the encoder pattern 20 is not accurate because each zone on the pattern has a width. Therefore,
As shown in FIG. 1 , an optical encoder 23 comprising a projector, a light receiver and a slit plate is provided in a lens driving mechanism, and the optical encoder 2 is driven by driving the lens.
The number of pulses generated from 3 is counted, and more accurate positions of the first lens group 10 and the second lens group 11 are detected.

Reference numeral 30 denotes a film set to face the aperture 31. The size of the normal shooting screen is determined by the size of the opening 32 of the aperture 31. 33 is a screen size change plate, usually are retracted from the film surface as shown in FIG. The screen size changing plate 33 is assumed to have the screen frame 3 shown in FIG. 7 described above (a). When switching the shooting screen size,
The screen size changing plate 33 is inserted in front of the film 30 by a switching mechanism (not shown), and the insertion detection switch 34 is turned on. Note that the screen size is not switched during shooting. Reference numeral 35 denotes a distance measuring device that detects a shooting distance L of a subject. Note that the shooting distance L may be obtained from the focus adjustment state of the shooting lens detected by the focus detection device. An exposure control device 36 controls a shutter and an aperture (not shown). Further, a half-press switch SW1 and a full-press switch SW2 for starting a photographing sequence are connected to the control circuit 37. Control circuit 37
Is constituted by a microcomputer and its peripheral components, and executes various control programs to be described later to perform various controls of the camera.

In general, the photographing magnification M is represented by the following equation, where f is the focal length of the photographing lens and L is the photographing distance. That is, even if the photographing distance L changes for each photographing, the photographing magnification M can always be kept constant by adjusting the focal length f of the photographing lens accordingly. But,
The screen size changing plate 33 is inserted in front of the film 30,
FIGS. 7 (a) the size of the photographing screen 1 as shown in the screen frame 3
When the shooting magnification M is set for the shooting screen 1 when the shooting magnification is changed, the above-described problem occurs. Therefore, the shooting magnification M ′ is set for the changed shooting screen so that the relationship between the changed shooting screen size and the subject image size is substantially equal to the relationship before the change. In this embodiment, since the width of the photographing screen 1 in the short side direction is reduced by the screen frame 3, the screen of the human image 2a when the photographing magnification M 'is set to the width of the photographing screen after the change in the short side direction The photographing magnification M ′ after the change so that the relation with the size in the short side direction is equal to the relation between the width in the short side direction of the photographing screen 1 before the change and the size of the human image 2 in the case of the photographing magnification M. Set.

The size of the screen frame of the screen size changing plate is not limited to this embodiment, and may be any size. When the screen size is changed by simultaneously reducing the long side direction and the short side direction of the shooting screen, the magnitude relationship between the shooting screen and the subject image before and after the change in both the long side and the short side directions of the shooting screen may be considered. .

FIG. 5 shows the relationship between the photographing magnifications β and γ, the photographing distance L and the focal length f. These data are stored in the memory of the control circuit 37. β is a photographing magnification M with respect to a normal photographing screen size, and γ is a photographing magnification M ′ with respect to the photographing screen size after the screen size is changed.
The numerical value on the right side of the vertical axis L is the photographing distance for the photographing magnification β, and the numerical value on the left side is the photographing distance for the photographing magnification γ. Also, the focal length f corresponding to those shooting distances
Is set on the stairs and is divided into the eight zones described above. Now, when the shooting distance is L, the shooting magnification M = β
Is between the photographing distances L6 and L7, the focal length zone is selected, and at the photographing magnification M = γ, the photographing distance L
Since it is between 4 'and L5', the focal length zone is selected.

FIG. 6 is a flowchart showing a control program executed by the microcomputer of the control circuit 37. With reference to this flowchart, a description will be given of the constant magnification control accompanying the switching of the photographing screen size. Step S1
Wait until the half-press switch SW1 is turned on, and if the half-press switch SW1 is turned on, the process proceeds to step S2. In step S2, distance measurement is performed by the distance measurement device 35, and in step S3, photometry is performed by a photometry device (not shown). In step S4, it is determined whether or not a constant magnification mode is set by a photographing mode setting device (not shown). If the constant magnification mode is set, the process proceeds to step S5; otherwise, the process proceeds to step S17. In step S5, the switch 34
It is determined whether or not the screen size changing plate 33 is inserted, that is, whether or not the shooting screen size is a normal size. If the size is the full size, the process proceeds to step S6; otherwise, the process proceeds to step S9.

In step S6, data relating to the photographing magnification β is read from the memory, and in the following step S7, the focal length f is calculated based on the photographing distance L and the photographing magnification M = β as the distance measurement result. In step S8, the focal length zone shown in FIG. 5 is determined. In step S9, data on the photographing magnification γ is read from the memory, and in the following step S10, the photographing distance L and the photographing magnification M = γ as the distance measurement result.
Is calculated on the basis of. In step S11, the focal length zone shown in FIG. 5 is determined.

In step S12, the first group lens 10 and the second group lens 11 are zoom-driven in accordance with the determined focal length zone. In the next step S13, the zone from the slider 21 sliding on the encoder pattern 20 described above. Is determined based on the information indicating that the zone has been reached in the above step, and if the zone has been reached, step S1
Proceed to 4. In step S14, the optical encoder 2
The counting of the pulse signal from step 3 is started, and in the following step S15, whether the pulse count value has reached a predetermined amount, that is, 1 is set to the position of the focal length f calculated in the above step.
It is determined whether or not the group lens 10 and the second group release 11 have been set. When the setting of the focal length f is completed, the process proceeds to step S16, and the motor 19 is stopped. Step S17
It is determined whether or not the half-press switch SW1 is turned on. If the switch is turned on, the process proceeds to step S18, and if it is off, the process returns to step S1. The process returns to step S17 until the full-press switch SW2 is turned on in step S18, and waits until the half-press switch SW1 is not turned off. If the full-press switch SW2 is turned on, the process proceeds to step S19. In step S19, an exposure calculation is performed based on the photometric result, and in the following step S20, exposure control is performed by controlling the exposure control device 36 and focusing.

As described above, when the photographing screen size is switched, the photographing magnification is set so that the relationship between the photographing screen size and the size of the subject image becomes substantially the same before and after the photographing screen size switching. The focal length of the lens is adjusted based on the shooting distance detected so that the shooting magnification becomes the same, so that part of the subject image does not protrude from the shooting screen size after switching, and the shooting screen Even if the size is switched, a photograph with a uniform composition is always obtained.

In the above embodiment, when the screen size is switched from the normal size to another size, the photographing magnification is switched to the photographing magnification corresponding to the changed screen size. Returning to, the constant magnification control may be stopped, and for example, manual zooming may be performed to adjust the photographing magnification to an appropriate value.

In the above embodiment, the photographing screen size is set to two types including the normal size, but more photographing screen sizes may be set. In this case, the photographing magnification may be set for each photographing screen size.

In the configuration of the above-described embodiment, the first lens group 10 and the second lens group 11 correspond to the zoom lens and the motor 1
9 is a driving means, a distance measuring device 35 is a distance measuring means, a control circuit 37 is a control means and a storage means,
3 is the switching means, the encoder pattern 20 and the slider 21 are the current position zone detecting means, and the encoder 23
Constitute pulse generating means.

[0024]

As described above, according to the present invention, a photographing magnification is set for each size corresponding to a plurality of photographing screen sizes, and when the photographing screen size is switched, the photographing distance is determined based on the detected photographing distance. Since the focal length of the zoom lens is adjusted so as to have a shooting magnification corresponding to the shooting screen size after switching, a part of the subject image does not protrude from the shooting screen size after switching.
Further, the zoom lens is driven by the driving unit until the zone detected by the current position zone detecting unit reaches the zone of the calculated focal length. When the zoom lens reaches the zone of the calculated focal length, the calculation is performed while counting the pulse signal of the pulse generating unit. Since the driving unit drives the zoom lens until the focal length is reached, the zooming can be quickly performed to the target focal length without burdening the control circuit. Also,
The shooting magnification is set so that the relationship between the size of the shooting screen and the size of the subject image is almost the same before and after the switching of the shooting screen size. Is obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a partial cross section of a camera according to an embodiment and a configuration of an apparatus.

FIG. 2 is a view showing a state where a cam groove is developed in a plane.

FIG. 3 is a diagram showing a state where an encoder pattern provided on the outer periphery of a cam cylinder is developed on a plane, and zone divisions of the encoder pattern.

FIG. 4 is a diagram showing a normal position of a screen size changing plate.

FIG. 5 is a diagram illustrating a relationship among a photographing magnification M, a photographing distance L, and a focal length f.

FIG. 6 is a flowchart showing a constant magnification photographing control program in accordance with screen size switching.

FIG. 7 is a diagram showing a relationship between a subject image before and after a screen size is changed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photographing screen 2, 2a Human image 3 Screen frame 10 1st-group lens 11 2nd-group lens 12, 13 Follower pin 14 Straight guide groove 15 Cam cylinder 16, 17 Cam groove 18 Reduction mechanism 19 Motor 20 Encoder pattern 21 Slider 23 Optical Type encoder 30 Film 31 Aperture 32 Opening 33 Screen size change plate 34 Insertion detection switch 35 Distance measuring device 36 Exposure control device 37 Control circuit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B ^7/ 02-7/105 G02B ⁷ /28-7/40 G03B 13/36

Claims (2)

(57) [Claims] A zoom lens; a driving means for driving the zoom lens; a distance measuring means for detecting a photographing distance; and a photographing magnification preset based on the photographing distance detected by the distance measuring means. A constant-magnification photographing apparatus for a camera, comprising: a control unit for adjusting a focal length of the zoom lens by the driving unit such that the driving unit has a plurality of photographing screen sizes, and a switching unit for switching between the photographing screen sizes; A storage unit for storing a photographing magnification set corresponding to each photographing screen size; a moving range from a tele end to a wide end of the zoom lens divided into a plurality of focal length zones; and a current position of the zoom lens. Current position zone detecting means for detecting in which focal length zone the camera is located, and pulse generating means for outputting a pulse signal for each predetermined amount of movement of the zoom lens The control means, when the photographing screen size is switched by the switching means, the photographing magnification corresponding to the photographing screen size after switching stored in the storage means and the detection detected by the distance measuring means The focal length is calculated based on the shooting distance, and the driving unit drives the zoom lens until the detection zone by the current position zone detection unit becomes the zone of the calculated focal length. A constant-magnification photographing device for a camera, wherein the driving means drives the zoom lens until the calculated focal length is reached while counting the pulse signals of the pulse generating means when the pulse signal is reached. 2. A constant-magnification photographing apparatus for a camera according to claim 1, wherein said photographing magnification is such that a relationship between a photographing screen size and a subject image size is substantially the same before and after the photographing screen size is switched. A constant magnification photographing apparatus for a camera, wherein the photographing screen is set for each photographing screen size.