JP3266762B2 - Optical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an optical apparatus provided with a finder having a variable focal length.

[0002]

2. Description of the Related Art Conventionally, a lens shutter camera with a zoom function which has a plurality of distance measurement areas (focus detection areas) in a shooting screen and can obtain distance information in each area is known.

A camera of this type is disclosed in
As disclosed in, for example, Japanese Patent No. 168111, when the zoom position (focal length) of the zoom lens system of the finder changes in conjunction with the movement of the photographing zoom lens, the position of the ranging area (ranging point) in the screen is switched. I was

In recent years, a single-lens reflex camera has also been commercialized in which a range-finding region can be arbitrarily selected by inputting a line of sight. It is conceivable to use a configuration in which a function of inputting by the above is added.

[0005]

However, the lens shutter camera, like a single-lens reflex camera, uses a finder for observation and TT through a zoom lens for photographing.
Unlike the method that performs the distance measurement in the L system, the finder (zoom lens system) and the distance measurement device are separate bodies. It is expected that there will be a problem that the position shifts.

FIG. 11 is a diagram showing the relationship between the field of view of a finder having a zoom function and the field of view of an AF (Auto Fucus) image sensor for performing distance measurement.

In FIG. 1, S1 to S5 denote a line-of-sight input position, and 6a and 6b denote an AF sensor array in which 150 sensor elements are arranged. In this figure, the sizes of the sensor arrays 6a and 6b at each zoom position are shown superimposed on the field of view of the finder.
(A) is WIDE, (B) is MIDDLE, (C) is T
At the time of ELE, the difference in the field of view of the sensor arrays 6a and 6b at each of these zoom positions is clearly shown. In addition, 6a is a right sensor, 6b is a left sensor, and is originally the eye-gaze input position S1.
To S5.

Here, for example, if S1 is selected as the line-of-sight input position, the position (corresponding sensor element) on the sensor array corresponding to the input position is 135 in the WIDE of FIG. In (B) MIDDLE, the position on the sensor array is at the 115th position, and in (C) TELE, the position on the sensor array is at the 105th position, and there is a shift between the line-of-sight input position and the distance measurement position at each zoom position.

Therefore, if the position within the viewfinder field and the position on the sensor array are simply fixed one-to-one and the distance measurement operation is performed by the line-of-sight input, depending on the zoom position, the subject intended by the photographer is in focus. Will not fit.

(Object of the Invention) An object of the present invention is to provide an optical device capable of focusing on a desired object in a visual field.
Is to provide equipment .

[0011]

In order to achieve the above object, the present invention provides a finder having a variable focal length and a plurality of different fixed distance measurement positions within a field of view of the finder.
Selecting means for selecting an arbitrary distance measurement position , a sensor array section including first and second sensor arrays, and a field of view of the finder at least partially overlapping the field of view of the finder and a change in the focal length. A projection optical system that projects a measurement field of view that does not change in response to a change on the first and second sensor arrays of the sensor array unit, a detection unit that detects a change in the focal length, Determining a position of an area on the first and second sensor arrays of the sensor array section corresponding to the selected distance measurement position, based on an output and an output of the detection means; Determining means for setting a fixed range that does not change according to a change in the viewfinder field of view and a selected distance measurement position, and wherein the first range determined by the determining means is
And an optical device that measures the distance of the object at the selected distance measurement position by detecting the positional relationship between the image of the object and the area range of the second sensor array.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a block diagram showing a main part of a camera according to an embodiment of the present invention, wherein 1 is a CPU for performing sequence control of the entire camera, and 2 is a zoom finder having a zoom lens system for changing magnification. A line-of-sight position detecting means for detecting a line-of-sight position within a plurality of distance measurement areas (i.e., whether or not the line of sight is directed) within a plurality of distance measurement areas. Zoom position detecting means 4 for detecting the focal length by detecting the position of the movable lens is a switch (SW1) for activating a camera sequence. 5 is a sensor array 6 (6
a, 6b) is a calculation area selection & calculation means for calculating the relative image shift of the subject image in the corresponding ranging area on the sensor arrays 6a, 6b upon receiving the video signal photoelectrically converted in (a, 6b).

The zoom lens system of the finder performs a zoom operation in conjunction with a zoom operation (lens movement) of the photographing zoom lens. Therefore, the focal lengths of both lens systems correspond one to one. Further, as the line-of-sight position detecting means 2, a known means can be used.

The sensor array 6 is composed of two sensor arrays 6a and 6b as shown in FIG.
Fifty (hereafter, n is described as n bits) sensors (photo sensors) are arranged. The distance measuring area of the sensor array 6 is set to have a size that covers the finder field of view when the zoom position is at the wide end, that is, the shooting angle of view (the state of FIG. 11A).

FIG. 3 is a view schematically showing a distance measuring optical system arranged in the camera having the above-described configuration.
At the time, the thin two-dot chain line is the view of the finder at the time of TELE,
The solid line is the field of view projected onto the corresponding sensor arrays 6a and 6b by the pair of light receiving lenses 7.

As is apparent from this figure, the finder visual field and the sensor visual field are shifted depending on the zoom position. The focus detection using the optical system of FIG. 3 recognizes the images reflected on the sensor arrays 6a and 6b in light and dark, quantifies the brightness of each sensor, and converts the corresponding object image on the sensor arrays 6a and 6b. This is performed by detecting the relative shift amount of.

For example, FIG. 4 (A), FIG. 5 (A), FIG.
As shown in (A), when a subject having a contrast located at different distances is measured at almost the center of the screen, the calculation is performed based on the 15-bit sensor data before and after the 75th bit of the 150-bit sensor. I do. At this time, the sensor data corresponding to 61 to 90 bits centered on the 75th bit is “0” in a dark place and “10” in a brightest place, as shown in FIGS. , FIG. 6B. The shift amount of this image is obtained by calculation, and this amount is A
It becomes F data (AFD).

The operation method is as follows.

The output of data received by the sensor array 6a is L (1),..., L (No), and the output of data received by the sensor array 6b is R (1),. The arrangement of the IC chips is as follows. (No) is the number of sensors in the array (= 150).

L (No) L (No / 2) L (1) R (No) R (No / 2) R (1) And f (n) ≡ (N ₁ , N ₂ ) is calculated. This corresponds to the degree of coincidence of the video data obtained from the left and right sensor arrays with respect to the shift n = N ₁ + N ₂ . (At this time, the designation bit of the number of the sensor array at which the calculation is performed is set to G.) Here, Wo are called windows, the number of sensor portion used in the calculation of the matching degree in the sensor array, N ₂ is N
Equal to ₁ or N ₁ +1 and “0 ≦ N ₁ + N ₂ ≦ + 30”
It is.

The minimum value of f (n) [f (n-1) ≧ f
(N) <f (n + 1), n = 1 to 29], and find n = n _min that satisfies Min f (n) among all the local minimum values.

This n _min is the relative displacement of the image,
It becomes AF data. (When the shift amount is 0, the AF data is 15
_AFD ) From the above calculations, each video data in the 30 calculation areas centered on 75 bits in FIG.
(B), the AF data is _calculated to be 29 _AFD .

In the case of FIG. 5A, the video data is in the state of FIG. 5B, and the AF data is 15 _AFD .

In the case of FIG. 6A, the video data is in the state of FIG. 6B, and the AF data is 1 _AFD .

The relationship between the AF data and the distance to the subject is determined based on the so-called triangulation principle based on the focal length of the light receiving lens 7, the base length of the two lenses, and the size of the sensor array. It should be noted that a distance to an object in a different direction, that is, a different position is detected based on the principle of the triangulation as described in, for example, US Pat.
No. 848.

Hereinafter, the sequence of the present invention will be described with reference to the flowchart of FIG.

When the switch SW1 is turned on (step 101), the CPU 1 starts a camera sequence. At this time, a battery check (not shown) is performed, but the description is omitted because it has no direct relation to the present invention. Next, the focal length of the photographing lens is detected by the zoom position detecting means 3,
That is, the zoom position is detected (step 102). Next, the gaze position detection unit 2 detects the gaze position of the photographer looking through the finder, thereby detecting where the photographer is in the field of view (step 10).
3). Then, the sensor arrays 6a,
6b to acquire sensor data (step 1)
04).

Next, the calculation area of the sensor data fetched in the above step 104 is
Is determined based on the zoom position detected in step (3) and the line-of-sight position obtained in step 103 (step 105).

For example, FIG. 8 is a diagram in which the field of view of the sensor is superimposed on the field of view of the finder when a subject having a contrast positioned at each distance is photographed in the WIDE state.

At this time, if the position of S2 is selected based on the line of sight, the sensor array 6a and 6b overlap the position of S2 in consideration of the state in which the sensor is superimposed on the finder at the time of WIDE in FIG. Sensor array 1
This corresponds to the same position as the 05th bit. Therefore, 30 bits centering on the 105th bit of the sensor array are determined as the calculation area.

FIG. 9 is a view in which the field of view of the sensor is superimposed on the field of view of the finder when a subject having a contrast positioned at each distance is photographed in the MIDDLE state.

At this time, if the position of S3 is selected by the line of sight input, the sensor array 6a, 6b is overlapped with the position of S3 in consideration of the state where the sensor is superimposed on the finder at the time of MIDDLE of FIG. 11B. (The position of S3 is the same as the 75th bit of the sensor array when
The 75th bit is not limited to WIDE and TELE). Therefore, 30 bits centering on the 75th bit are determined as the calculation area.

FIG. 10 is a view in which the field of view of the sensor is superimposed on the field of view of the finder when a subject having a contrast positioned at each distance is photographed in the TELE state.

At this time, if the position of S5 is selected by the line of sight, the sensor array 6a, 6b is overlapped with the position of S5 in consideration of the state in which the sensor is superimposed on the finder at the time of TELE in FIG. 11C. Time sensor array 4
This corresponds to the same position as the fifth bit. Therefore, 30 bits centered on the 45th bit are determined as the calculation area.

The above-described calculation is performed based on the video data obtained from the plurality of sensors in the calculation area determined as described above to form AF data (step 106).

The method of obtaining a subject distance using the AF data and performing focusing on the subject by a photographing lens is the same as that of a conventional lens shutter camera.

According to the above-described embodiment, the distance measurement area input with the line of sight and the zoom position at that time specify a distance measurement area having a size enough to cover the viewfinder field at any zoom position. Calculation area (3 in the embodiment)
0 bit) is selected, so in a camera having a passive AF function in which the viewfinder and the distance measuring device are separate bodies, regardless of the zoom position of the taking lens,
It is possible to always perform the distance measurement at the position selected by the line of sight input. That is, it is possible to perform shooting in focus on the subject intended by the photographer.

It should be noted that instead of selecting a distance measuring position by eye-gaze input, a distance measuring position (area) may be selected by a dial or the like. Instead of using the sensor arrays 6a and 6b, a long single sensor array may be used. Further, photometry may be performed from the magnitude of the video data in the determined calculation area.

In the above embodiment, a lens shutter camera is assumed. However, a finder and a distance measuring device are separate units, and a passive AF function such that a plurality of distance measuring areas can be selected is provided. A camera having the same can be similarly applied. Furthermore, the present invention can be applied to other optical devices and other devices, and further to a constituent unit.

[0041]

As described above, according to the present invention, it is possible to focus on a desired object in a visual field.
Optical equipment.

[0042]

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a configuration of a sensor array in FIG. 1;

FIG. 3 is a diagram schematically illustrating an optical system arranged in the camera of FIG. 1;

FIG. 4 is a diagram illustrating a relationship between a finder visual field and a sensor visual field at a short distance and a sensor output in the present embodiment.

FIG. 5 is a diagram illustrating a relationship between a finder visual field and a sensor visual field at a middle distance in the present embodiment and a sensor output thereof.

FIG. 6 is a diagram showing a relationship between a finder visual field and a sensor visual field at a long distance in the present embodiment and a sensor output thereof.

FIG. 7 is a flowchart illustrating an operation of a main part of the camera in FIG. 1;

FIG. 8 is a diagram showing a relationship between a finder visual field and a sensor visual field at each subject distance at the time of WIDE in the present embodiment.

FIG. 9 is a diagram showing a relationship between a finder visual field and a sensor visual field at each subject distance at the time of MIDDLE in the present embodiment.

FIG. 10 is a diagram showing a relationship between a finder visual field and a sensor visual field at each subject distance at the time of TELE in the present embodiment.

FIG. 11 is a diagram for explaining a problem expected when performing autofocus in a lens shutter camera with a zoom function.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 2 Line-of-sight detection means 3 Zoom position detection means 5 Calculation area selection & calculation means 6a, 6b Sensor array

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B ^7/ 28-7/40

Claims (1)

(57) [Claims] And 1. A variable focal length of the finder, a plurality of fixed distance measuring different positions within the field of view of the finder
Selecting means for selecting an arbitrary ranging position ; first and second selecting means;
And a sensor array portion comprising a sensor array of the above, and a measurement field of view that at least partially overlaps the field of view of the finder and does not change in response to a change in the field of view of the finder due to a change in the focal length. And the second
A projection optical system for projecting onto the sensor array, detecting means for detecting a change in the focal length, and an output corresponding to the selected distance measurement position based on an output of the selecting means and an output of the detecting means. The position of an area on the first and second sensor arrays of the sensor array section is determined, and the range of the area is a constant which does not change in accordance with a change in the finder field of view and a selected distance measurement position. Determining means for determining the range, and detecting the positional relationship of the image of the object in the area range of the first and second sensor arrays determined by the determining means, thereby detecting the object at the selected distance measurement position. An optical device for measuring a distance.