JP2952953B2 - Camera with automatic focus detection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly, to a camera that can automatically detect a focus state of a lens on a subject.

[Related Art] In recent years, cameras having a so-called autofocus function for automatically adjusting a focus have been increasing. In such a camera, a distance measurement frame indicating a position where the distance of the subject is measured is generally displayed in a viewfinder.
The configuration is such that the photographer is notified of which subject is in focus.

[Problems to be Solved by the Invention] With the conventional camera as described above, the photographer learns the position of the ranging frame when the user becomes accustomed to the operation of the camera. Can get in the way.

On the other hand, a so-called multi-point ranging camera with multiple ranging frames expands the ranging area, making it possible to capture the main subject sufficiently, regardless of the individual position of the ranging frame. It is. Therefore, it can be said that in such a multi-point distance measuring camera, the existence of the distance measuring frame is not particularly necessary.

In Japanese Patent Application Laid-Open Nos. 60-64334 and 60-64335, a ranging frame is displayed in a viewfinder until a focus signal is output. A camera for deleting a distance frame is disclosed.

However, with such a camera function, it is good to release the camera immediately after focusing, but this is a problem with a camera that uses focus locking after focusing. That is, if the subject is moving, the subject becomes out of focus with the passage of time, and in that case, it is unclear which position of the actual subject is in focus, so that the usability cannot be said to be good.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a camera capable of selectively displaying or hiding a distance measuring frame in a finder according to the skill of a photographer. And

[Means for Solving the Problems] To solve the above problems, a camera having an automatic focus detection device according to claim 1 of the present invention comprises: a detection unit for detecting a focus state of a photographing lens with respect to a subject; Display means for displaying the position of the subject to be detected by the detection means, and selection means capable of independently selecting a first mode in which the display means is activated and a second mode in which the display means is not activated, independently of the detection means And characterized in that:

A camera having the automatic focus detection device according to claim 2,
The selection means according to claim 1 is characterized in that the selection is performed by a manual operation.

A camera having the automatic focus detection device according to claim 3,
Detecting means for detecting the focal length of the photographing lens with respect to each of the objects present at a plurality of positions; one detecting output automatically selected from a plurality of detecting outputs of the detecting means; A first mode in which an area including the position of a subject is displayed in a finder, and one detection output is manually selected from a plurality of detection outputs of the detection means, and the position of the selected subject is displayed in the finder. Selection means for selecting a second mode and a third mode in which one detection output is automatically selected from a plurality of detection outputs of the detection means and all detected object positions are not displayed in the viewfinder. And characterized in that:

A camera having the automatic focus detection device according to claim 4,
In addition to the configuration of the invention according to claim 3, further comprising a switching means for switching one detection output selected when the second mode is selected to a detection output for another position of the subject. It is characterized by.

In a camera having the automatic focus detection device according to claim 5, the selection means according to claim 4 includes a first switching means, and the switching means includes a second switching means,
The selection means is activated by the first switching means even when the switching means is activated by the second switching means.

[Operation] In the invention according to the first aspect, whether or not the position of the subject is displayed in the finder is selected independently of the detecting means for detecting the focus state of the photographing lens with respect to the subject.

In the invention according to claim 3, one mode is selected from a plurality of modes related to the display of the position of the subject in the finder.

FIG. 1 is a block diagram showing a main configuration of a camera according to an embodiment of the present invention.

In the figure, light incident through a photographing lens 9 is reflected by a finder mirror 4, enters a pentaprism 1 through a reticle 3 and a transmissive liquid crystal (LCD) 2, and then passes through a finder lens 18. And enters the photographer as an image. On the other hand, of the light incident on the finder mirror 4, the light of an amount necessary for focus detection is partially
Passes through the sub-mirror 5 and enters the focus detection unit 8. The focus detection unit 8 includes an optical system necessary for performing focus detection, and includes a sensor, a data output unit, and the like. The control circuit 7 outputs the data for controlling the focus detection sensor, the sequence, the LCD drive circuit 6, and the like based on the input data. The LCD drive circuit 6 controls the transmission type liquid crystal 2 based on the control data output from the control circuit 7 and performs various liquid phase displays.

FIG. 2 is a diagram showing a specific configuration of the focus detection unit 8 in FIG.

In the drawing, the light reflected from the sub-mirror 5 in FIG. 1 is formed on the CCD substrate 11 as four sets of light beams by a re-imaging lens via a condenser lens 14. Autofocus in this embodiment (hereinafter referred to as “AF”)
The method is a known phase difference detection method. Here, the aperture mask 13 is set so as to be superimposed on the re-imaging lens 12, and its opening removes light unnecessary for focus detection coming from the condenser lens 14. The CCD substrate 11 has a pair of line sensors 11-a, 11-b, 11-c and 11-d corresponding to four detection areas consisting of focus detection areas a, b, c and d which will be described later. Is formed thereon.

FIG. 3 is a diagram showing a state of a photographing screen of a camera according to an embodiment of the present invention.

In the figure, the CCD screen 1 shown in FIG.
A distance measurement area corresponding to each line sensor formed on 1 is shown.

FIG. 4 shows a viewfinder according to an embodiment of the present invention.
This shows a state where all the distance measurement frames are displayed on the LCD display unit. In the figure, a solid line is a liquid crystal display displayed on the LCD display unit, and a dotted line corresponds to the distance area shown in FIG.

Here, the ranging frame display 16 is displayed when shooting is performed in the wide AF state for the entire ranging area. The small ranging frame displays 17a to 17d
A spot AF state is displayed when distance measurement is performed based on each distance measurement area.

Here, the spot ranging frames are referred to as a center spot frame 17a, an upper spot frame 17b, and a left spot frame 17.
c and the right spot frame 17d.

FIG. 5 is a diagram showing a configuration of a control unit according to one embodiment of the present invention.

In the figure, a control circuit (microcomputer μC)
7 is provided with inputs from various switching means.
The switch Sar is an area changeover switch for changing the distance measurement area to a desired area as described later. When the switch Sar is turned on, an ON signal is input to the port P1. The switch Sch switches a spot area in the ranging area as described later, and an ON signal is input to the port P2 when the switch Sch is turned on. And AND circuit 2
2, an input signal is supplied to the port P3 only when one of the switches Sar and Sch is turned on, and an AF area routine to be described later is entered.

The switch S1 is a switch made by pressing the release button one step, and when turned on, an ON signal is input to the port P4 to start the AF operation. And port P5
, The ON / OFF state of the switch S1 is determined. A switch Sa, a switch Sb, and a switch Sc are vertical / horizontal detection switches that indicate the direction in which the camera is held during shooting. The photographing posture of the camera is detected by a configuration described later, and each ON signal is input to the control circuit 7 through the ports P6 to P8. Switch S _AF / _FA switch is a switch that switches between autofocus shooting or focus detection (FA) shooting that only performs focus detection and does not drive the lens. When turned on, an on signal is input to port P9. You.

On the other hand, data is input from the focus detection unit 8 to the control circuit 7, and control data for controlling the focus detection unit 8 is output from the control circuit 7. The control output of the control circuit 7 is transmitted to a transmission type liquid crystal (LCD) 2 through a liquid crystal controller (LCD C) 6.
Is controlled. Further, the control output of the control circuit 7 is output to a lens drive control circuit (LE · C) 20 to control the drive of the lens for autofocus.

FIG. 6 shows a control flow performed when the switch S1 is turned on.

First, when this flow is entered by turning on the switch S1, an interrupt prohibition process is performed in step S1 in order to prohibit an interrupt from being performed thereafter. Next, an AF area is displayed in step S2. This display is based on the area (AR) value,
The D drive circuit 6 controls the LCD 2 for display. In the initial state of switch-on, a normal wide display (AR1) is normally displayed.

Next, in step S3, AF data, that is, distance measurement data is input from all the distance measurement areas. Then, the defocus amount for each area, that is, the area DF (DFa, D
Fb, DFc and DFd) are calculated (step S4).

In step S5, whether or not the AF area is in the wide state is determined based on whether the spot flag SPTF indicating the spot area display is “0” or “1”. AF area is wide AF
In the state, one defocus amount DF is calculated by a predetermined method from the defocus amount of each area obtained in step S4. Note that the spot flag SPTF is reset (“0”) when the power is turned on.

On the other hand, when the camera is not in the wide AF state (NO in step S5),
In step S7, a spot area is determined. When the spot ranging area is a, the value DFA of the ranging area a is used as the defocus amount in step S8. Similarly, in the case of areas b, c and d, the defocus amounts DFb, DFc and DFd are used as the defocus amounts, respectively.

Defocus amount DF obtained above in step S12
Is smaller than or equal to a predetermined value K. When the defocus amount is equal to or less than the predetermined value, it is determined that the object is in focus, so that in-focus display is performed in step S13. If the defocus amount is larger than the predetermined value K, it is determined in step S14 whether the mode is the auto focus mode or the focus aid mode. When in auto focus mode,
Based on the defocus amount DF obtained in S15, the lens is driven to bring the lens into focus. On the other hand, when in the focus aid mode, the lens is not driven, and step S1
Proceed to 6.

In step S16, it is determined whether the switch S1 is off. If the switch S1 has not been turned off, the process returns to step S2, and the above-described operation is repeated. On the other hand, when the switch S1 is turned off, it is determined that the operation of the switch S1 has been completed, the display of the LCD display unit is turned off in step S17, and interruption is permitted in step S18 to stop.

FIG. 7 is a flowchart showing the specific contents of the AF area routine according to one embodiment of the present invention.

This routine is executed by turning on and off the switches Sar and Sch. When entering this flow, to prioritize this flow in step S30,
Other interrupts are prohibited. Then, in step S31, the ranging area is displayed on the LCD display unit according to the AR value indicating the display state of the ranging area. In step S32, it is determined whether or not the spot flag SPTF is "1". When this flag is "1", that is, when the spot area is displayed, it is determined in step S33 whether or not step Sar is turned on. Here, the switch Sar is as shown in FIG. 5, but is specifically arranged in the camera as shown in FIG. That is, by turning on the switch Sar provided on the camera body 25, the ranging area is switched. Further, as shown in FIG. 12, a switch Sch is also provided on the upper surface of the camera body 25. Each time the switch Sch is slid to the right (the position indicated by the broken line), the switch is turned on. Then, when the user releases his / her hand, the switch is urged by the spring to return to the original position, and the switch is turned off.

When the switch Sar is turned on in step S33, the value of AR is set to AR1 in order to obtain the normal wide display shown as AR1 as shown in FIG. Then, in step S35, the spot flag SPTF is set to “0”, and the process proceeds to step S53. On the other hand, when the switch Sar is not turned on in step S33, the spot area is displayed, so that step S3
At 6, the photographing posture of the camera is detected. The posture of the camera is specifically shown in FIGS. 9 and 10A to 10C.

In FIG. 9, the vertical / horizontal detection switches Sa, Sb and Sc are configured as shown in the figure. That is, the inclined portion is filled with mercury, and the mercury moves to one of the switches Sa to Sc together with the shooting posture of the camera, so that a current flows through the switch. As a result, the photographing posture is detected by changing any one of the potentials of the ports P6 to P8 corresponding to each switch shown in FIG. 5 from “H” to “L”. 10A to 10C show specific photographing postures of the camera.

Next, in step S37, the value AR _NEW indicating the currently set ranging area is treated as the ranging area. However, in the initial state, the value of the distance measurement area value AR _NEW is generally the spot value AR4 which is generally considered to be the most frequently used.
(See Figure 11A).

Next, since the shooting posture is detected by the vertical / horizontal detection switches Sa to Sc shown in FIG. 9, any one of the steps S38 to S40 is performed for each position. For example, if the shooting posture is the horizontal position, step S3
If the value of the distance measurement area AR is set to AR4 as the initial value in 8, the display position of the spot distance measurement area changes in a cycle such as AR4 → AR5 → AR6 → AR7 → AR4.

The eleventh state shows the specific change state of this display position.
It is FIG. A-FIG. 11C. Here. 11A diagrams the operation of the step S38, the ie shows a case photographing posture is horizontal position (switch Sb is turned on), the 11B diagrams processing i.e. photographing posture vertical position of the step S39 (step S _a is FIG. 11C shows the process of step S40, that is, the change of the display when the shooting posture is in the vertical position (the switch _Sc is on).

Then, in step S41, one of the ARs indicating the distance measurement area
The value is used as the distance measurement area AR, and the distance measurement area AR is used for the set position AR _NEW in step S42. Then, the process proceeds to step S53.

On the other hand, when the spot flag SPTF is not “1” in step S32, that is, when the spot display is not attached, it is determined in step S43 whether the area changeover switch Sar is on. When this switch is not turned on,
In step S47, the distance measurement area value AR is displayed as a spot, that is, A
It is determined whether or not it is R2. If it is the spot display, the spot flag SPTF is set to "1" in step S48, and the process returns to step S36. By detecting the photographing attitude, the above-described spot display position changing process is performed. If the distance measurement area value AR is not AR2, the process proceeds to step S53.

When the area changeover switch Sar is on in step S43, it is determined in step S44 whether the mode is the auto focus mode or the focus aid mode. In the focus aid mode, in step S46, when the distance measurement area value is AR2, the distance measurement area value is set to AR1, when the distance measurement area value is AR1, the value is AR2, and when the distance measurement area value is AR3, The distance measurement area value is set to AR1.

When in the auto focus mode, step S45
, The display change cycle shown in FIG. 8 is performed. That is, if the display of the current distance measurement area is AR1, which indicates a normal wide display, the AR is displayed each time the switch Sar is turned on.
The display changes in the order of 1 → AR2 → AR3 → AR1.

Next, in step S49, it is determined whether or not the distance measurement area value AR is 2. When the distance measurement area value is AR2, the spot flag SPTF is set to “1” in step S50, and the process proceeds to step S51.
In the distance measurement area value AR, the current distance measurement area value of the spot display
AR _NEW is entered. On the other hand, if it is not AR2, AR1 or AR3 is input to the distance measurement area value AR, and a display indicating the distance measurement area is made based on the distance measurement area value AR in step S53. After waiting for the switches Sar and the switch Sch to be turned off in steps S54 and S55, an interrupt is permitted in step S56. Then, in step S57, the timer is reset and counting is started. In step S58, after elapse of 5 seconds, the liquid crystal display of the LCD is turned off in step S59, and this flow is stopped.

[Effect of the Invention] As described above, in the invention according to claim 1, the presence or absence of the display indicating the position of the subject in the viewfinder is selected independently of the detection of the focus state of the photographing lens with respect to the subject, so that the photographer The display can be turned off or turned on depending on the level of skill of the user, and the usability for shooting is improved.

As described above, since one mode is selected from a plurality of modes related to the display of the position of the subject in the viewfinder, focus detection and photographing according to the photographing situation of the subject can be performed, as described above. Usability is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a main part of a camera according to an embodiment of the present invention, FIG. 2 is a diagram showing a specific configuration of a focus detection unit in FIG. 1, and FIG. FIG. 4 is a view showing the arrangement of the distance areas, FIG. 4 is a view showing the positional relationship between the arrangement of the CCD substrate in FIG. 2 corresponding to the distance measurement areas in FIG. 3 and the distance measurement frame, and FIG. FIG. 6 is a block diagram of a control unit according to the embodiment, FIG. 6 is a flowchart showing control executed when the switch S1 of FIG. 5 is turned on, and FIG.
FIG. 8 is a flowchart showing the control executed when either the switch Sar or the switch Sch is turned on, and FIG. 8 shows a display of a ranging frame in the finder which is switched when the switch Sar of FIG. 5 is turned on. 9, FIG. 9 is a diagram showing the structure of the vertical and horizontal switches Sa, Sb and Sc of FIG. 5, FIGS. 10A to 10C are diagrams showing the shooting posture of the camera corresponding to the vertical and horizontal switches Sa to Sc, FIG. FIG. 11A is a diagram showing a change in the display of the distance measurement frame in the finder when the vertical / horizontal switch Sb in FIG. 5 is turned on, and FIG. 11B is a view in the finder when the vertical / horizontal switch Sa in FIG. 5 is turned on. FIG. 11C is a diagram showing a change in the display of the distance measurement frame, FIG. 11C is a diagram showing a change in the display of the distance measurement frame in the finder when the vertical / horizontal switch Sc in FIG. 5 is turned on, and FIG. Changeover switch Sa
FIG. 4 is a diagram showing a specific arrangement of r and a spot changeover switch Sch on a camera body. In the figure, 2 is an LCD display unit, 6 is an LCD drive circuit, 7 is a control circuit, 8 is a focus detection unit, 18 is a finder lens, 11
Is a CCD substrate, 12 is a re-imaging lens, 13 is an aperture mask, 14 is a condenser lens, 15 is a shooting screen, 16 is a distance measurement frame in wide display, 17a is a distance measurement frame in the center spot display, and 17b is an upper spot display Frame, 17c is a frame with left spot display, 17d is a frame with right spot display, 2
0 is a lens drive circuit, Sar is a changeover switch, and Sch is a spot display changeover switch. In the drawings, the same reference numerals indicate the same or corresponding parts.

Continued on the front page (72) Inventor Hiroshi Otsuka 2-3-13 Azuchicho, Chuo-ku, Osaka City, Osaka Prefecture Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Hiroshi Ueda 2-chome Azuchicho, Chuo-ku, Osaka City, Osaka Prefecture No. 3-13 Osaka Kokusai Building Minolta Camera Co., Ltd. (56) References JP-A-60-64335 (JP, A) JP-A-57-79834 (JP, U) (58) Fields investigated (Int. Cl. ^6, DB name) G03B 17/18 - 17/20 G03B 17/36

Claims (5)

(57) [Claims] 1. A detecting means for detecting a focus state of a photographing lens with respect to a subject, a displaying means for displaying a position of a subject to be detected by the detecting means in a finder, and a first mode for activating the displaying means A camera having an automatic focus detection device, comprising: a selection unit that can select a second mode in which the display unit is not activated, independently of the detection unit. 2. The camera according to claim 1, wherein said selection means selects by manual operation. 3. A detecting means for detecting a focal length of a photographing lens with respect to each subject present at a plurality of positions, and one detecting output is automatically selected from a plurality of detecting outputs of said detecting means, and said detecting is performed. A first mode in which an area including the positions of all the objects detected by the means is displayed in a viewfinder; one detection output is manually selected from a plurality of detection outputs of the detection means; and the position of the selected object is selected. And a third mode in which one detection output is automatically selected from a plurality of detection outputs of the detection means and all detected object positions are not displayed in the finder. A camera having an automatic focus detection device, comprising: selecting means for selecting 4. The apparatus according to claim 3, further comprising switching means for switching one detection output selected when said second mode is selected to a detection output for another position of the subject. A camera having the automatic focus detection device according to claim 1. 5. The apparatus according to claim 1, wherein said selecting means includes first switching means, said switching means includes second switching means,
5. The automatic focus detecting device according to claim 4, wherein said selecting means is activated by said first switching means even when said switching means is activated by said second switching means. Camera with device.