JPH05232371A - Device for displaying depth of field - Google Patents

Abstract

PURPOSE:To confirm the depth of field even when a lens is not stopped down whether the lens is interchangeable or not by displaying whether an object is within the depth of field or not based on the focal distance of the lens, a diaphragm value and the depth of field calculated from an object distance. CONSTITUTION:When a half-depressing switch 8 is depressed in a state where the lens 1 is opposed to the object A, the object distance of the object A is measured by a range-finding device 3, and the depth of field is calculated, then the calculated value is stored. A CPU 7 controls the respective devices of a camera, and calculates the depth of field of the objects A and B so as to confirm whether or not the object distance is within the depth of field. The direction of the camera is changed in a state where the switch 8 is depressed(focusing lock where the measured distance is stored and held) so as to oppose another object B and catch it in the range-finding area. In the case that the object distance of the object B measured by the device 3 is within the depth of field concerning the object A, a pilot lamp 14 under a finder 11 is flickered and when it is not within the depth of field, the lamp 14 is in an unlighted state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a depth of field display device for a camera.

[0002]

2. Description of the Related Art In a conventional single-lens reflex camera, the depth of field is confirmed by visually narrowing the aperture of the lens down to the aperture value at which the image is actually photographed in the viewfinder. There was no confirmation method for compact cameras.

However, when the aperture of the lens is narrowed down in the conventional single-lens reflex camera, the amount of light is reduced and the inside of the finder is darkened, so that the range of the depth of field cannot be accurately determined.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a depth-of-field display device capable of confirming the depth-of-field in a wide-open aperture state.

[0005]

In order to solve the above-mentioned problems, the present invention provides a camera having distance measuring means for measuring a subject distance in a predetermined distance measuring area, wherein The calculation means for calculating the depth of field from the focal length and the aperture value and the subject distance of another subject measured by the distance measuring means are calculated by the calculation means by comparing with the focusing distance. A determination means for determining whether or not the depth of field is within the range, and a determination result when the determination means determines whether or not the subject in the distance measuring area is within the depth of field range. A depth-of-focus display device including a display unit for displaying and a control unit for controlling the judgment display unit is configured. Further, a depth of focus display device for displaying by lighting or blinking the display body is constructed.

[0006]

According to the depth of field calculated from the focal length and aperture value of the lens and the subject distance, whether or not the subject is within the depth of field is displayed. At this time, it is not necessary to narrow the aperture.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of the first embodiment, and FIG. 2 is a diagram showing the relationship between the object scene and the viewfinder display.

The lens (1) has a unique focal length, and a diaphragm mechanism is installed so that the focal length and the diaphragm value are CPU.
It is transmitted to (7). A distance measuring device (3) is provided on the camera body (2) to measure the subject distance. The exposure value setting device (4) measures the illuminance of the subject and selects the aperture value and shutter speed of the lens (1) based on the result. The display device (5) displays the aperture value, shutter speed and other shooting data. The exposure control device (6) controls the shutter speed. In addition to the above, the CPU (7) is a central control unit that controls each device of the camera, calculates the depth of field of the subject, and checks whether or not the subject distance is within the depth of field range.
The switches (8) and (9) are connected to the CPU (7). The switch (8) is a half-push button, and when pressed, the depth of field is calculated and set. The switch (9) is a release button, which is a switch for releasing the shutter when pressed. The motor (10) is a motor that drives a lens group forming the lens (1) according to the distance measurement result of the distance measuring device (3).

Next, the operation will be described. This embodiment is an example in which there are three distance measuring areas in the left-right direction of the shooting screen. When the lens (1) faces the subject (A) and the switch (8), which is a half-push button, is pressed, the distance measuring device (3) moves the lens to 3
The subject distance of each point is measured, and a focusing lens group (not shown) is driven by a motor (10) to focus on the basis of the distance measurement result. On the other hand, the aperture value of the lens (1) is set by the exposure value setting device (4), and the focal length of the lens (1) is fixed or set by the photographer. This focal length information is set from the lens (1) to the camera body ( It is transmitted to 2). C
The PU (7) calculates the depth of field based on the above three data, that is, the subject distance, the aperture value, and the focal length.

The depth of field is displayed on the finder screen (1
1). Indicator lights (1
2a, 12b, 12c) are provided. In the focused distance measuring area, the indicator lamp (12b) is turned on to indicate that the focus is achieved. In the range-finding area of the subject (B) within the depth of field, the indicator lamp (12c) blinks to indicate that it is within the depth of field. In the range-finding area of the subject (C) outside the depth of field, the indicator lamp (12a) remains off,
Indicates that you are not within the depth of field. That is, the indicator lamps (12a, 12b, 12c) perform both focusing display for the subject and depth of field display as a single display member. With respect to the depth of field, if the photographer's intention is met, the switch (9) is subsequently pressed to perform shutter release. When it is against the intention, the pressing of the switch (8) is released, the aperture value, the focal length or the subject distance is changed, and the switch (8) is pressed again to newly calculate the depth of field.

Next, the flow will be described with reference to FIG.
In step 1, the switch (8) is pressed to activate the flow for displaying the depth of field, and the process proceeds to step 2. At this time, none of the indicator lights (12a, 12b, 12c) is lit. In step 2, the object distance is measured for each distance measuring area, and the process proceeds to step 3. The final focus data for driving the lens (1) based on the distance measurement results of the shots
It is calculated by U (7). Here, it is assumed that the data for focusing on the subject (A) shown in FIG. 2A is obtained.
In step 3, the data of the aperture value and the focal length of the lens (1) are read and the process proceeds to step 4. In step 4, the depth of field is calculated for the subject (A) and step 5
Proceed to. Since the subject (A) is in focus in step 5, the indicator lamp (12b) is turned on and the process proceeds to step 6.
In step 6, it is checked whether the subject (B) is within the depth of field for the subject (A). If it is within the depth of field, go to step 7. If it is not within the depth of field, go to step 8. In step 7, the indicator light (12c) corresponding to the subject (B) is blinked and the process proceeds to step 9.
In step 8, the indicator light (1
2c) is turned off and the process proceeds to step 9. In step 9, it is checked whether the subject (C) is within the depth of field for the subject (A). If it is within the depth of field, go to step 10. If it is not within the depth of field, go to step 11. In step 10, the indicator light (12a) corresponding to the subject (C) is turned on and the process proceeds to step 12.
In step 11, the indicator lamp (12a) corresponding to the subject (C) is kept off, and the process proceeds to step 12 and ends.

Next, a second embodiment will be described with reference to FIG. Fig. 3 shows the viewfinder (11) display and indicator light (13
(a, 13b, 13c) FIG. The position of the indicator lamps (13a, 13b, 13c) indicating whether or not it is within the depth of field is not in the viewfinder (11) screen, but in a position directly below the viewfinder (11) screen and corresponding to each distance measuring area. It is installed in. Others are the same as those in the first embodiment, and the description thereof will be omitted.

Next, a third embodiment will be described with reference to FIG. FIG. 4 shows the viewfinder (11) display and the indicator light (1
It is a figure which shows 4). The indicator light (14) is a viewfinder (1
1) It is provided just below the screen. In this embodiment, there is one distance measuring area, and therefore, the indicator lamp (14) is one example. The description of the same points as in the first embodiment will be omitted. When the lens (1) faces the subject (A) and the switch (8) is pressed, the distance measuring device (3) measures the subject distance of the subject (A), and the depth of field is calculated and calculated. The value is stored. When the switch (8) is kept pressed (focus lock for storing and holding the distance-measuring distance), the direction of the camera is changed to face the other subject (B) in the distance-measuring area and the distance-measuring device (3 When the subject distance of the subject (B) measured by) is within the depth of field of the subject (A), the indicator light (14) blinks, and when it is not within the depth of field, the indicator light (14) is turned off. It remains in the state.

When there are a plurality of distance measuring areas, it goes without saying that the distance can be measured and the depth of field can be calculated in any of the distance measuring areas without defining the distance measuring area for focusing. .. This embodiment can be carried out regardless of whether or not the lens can be replaced. In a camera in which the lens is not exchanged, information about the focal length of the lens can be stored in advance.

[0015]

According to the present invention, whether or not the subject is within the depth of field is displayed based on the depth of field calculated from the focal length and aperture value of the lens and the subject distance. Whether or not the lens is replaceable, you can check the depth of field without narrowing down.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a diagram showing a relationship between a subject and display of a viewfinder of a camera according to the first embodiment.

FIG. 3 is a diagram showing a viewfinder display and an indicator lamp of a camera of a second embodiment.

FIG. 4 is a view showing a viewfinder display and an indicator lamp of a camera of a third embodiment.

FIG. 5 is a flowchart of the first embodiment.

[Explanation of symbols]

 1 Lens 2 Camera Body 3 Distance Measuring Device 4 Exposure Value Setting Device 5 Display Device 6 Exposure Control Device 7 CPU 8, 9 Switch 10 Motor 11 Finder Screen 12, 13, 14 Indicator Light

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location G03B 17/20 7316-2K

Claims (2)

[Claims] 1. In a camera having a distance measuring means for measuring a subject distance in a predetermined distance measuring area, a calculation for calculating a depth of field from a focusing distance of one subject and a focal length and an aperture value of a photographing lens. Means and the subject distance of another subject measured by the distance measuring means is compared with the in-focus distance to determine whether or not it is within the range of the depth of field calculated by the calculating means. Determination means, display means for displaying the determination result when it is determined by the determination means whether or not the subject in the distance measurement area is within the depth of field, and control for controlling the determination display means And a depth-of-field display device. 2. The depth-of-field display device according to claim 1, wherein the display of the judgment result of the judgment display means is performed by lighting or blinking a display body.