JPH01198715A - Focus detector - Google Patents

Abstract

PURPOSE:To eliminate the trouble of switching to a distance measuring position which is frequently used and to improve operability by measuring distance at a distance measuring position stored in a storing means by means of the selection of a photographer and storing a distance measuring position which photographer frequently uses. CONSTITUTION:The title detector is provided with a distance measuring means 2 which detects distance from plural distance measuring positions in an image to an object respectively, a distance measuring position selecting means 4 which selects plural measuring distance positions, a storing means 9 which stores the distance measuring positions selected by means of the distance measuring position selecting means 4, and a control means 4 which performs driving and controlling. The control means 4 performs driving and controlling in the way that a focusing position is decided at the distance measuring position stored in the storing means 9 and a photographing lens driving means 10 is adapted to the focusing position. Thus, a distance-measurable condition can be kept at the distance measuring position selected by the photographer, for example, at the distance measuring position frequently used. In said condition even if photographing is performed at some other distance measuring position, distance measuring at the distance measuring position frequently used is automatically performed in a next photographing operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a multi-point distance measurement type focus detection device that detects the focus of a plurality of points or arbitrary points within a screen.

[Prior art] As a conventional multi-point distance measuring method focus detection device,
There is No. 2-19823.

As shown in Fig. 3(a), this sensor is equipped with a distance measuring sensor 2° in which two or more pairs of light receiving elements 2°a and 2°b are arranged, and the output from the distance measuring sensor 2° is A. /D converter 3 to microprocessor unit (M, P, U) 4
The lens drive unit 10 for driving the ti shadow lens is driven and controlled to perform focus adjustment.

Focus adjustment in this case, especially in passive distance measuring devices, involves dividing the screen into multiple ranging blocks (AI, A2, A3) as shown in Figure 3(b). ,
The light-receiving elements of the distance measurement sensor 2° are roughly divided into a plurality of groups corresponding to each of the distance measurement blocks (At, A2°A3), and the selection switch SL is turned on to select the distance measurement block ^1, and similarly the switch S2 is turned on. The distance measuring block 82 is selected by the switch S3, the distance measuring block A3 is selected by the switch S3, and the distance measuring block ^1+A2 is selected by the switch S4, respectively, and the subject in the selected ranging block is focused on as the main subject.

[Problems to be Solved by the Invention] Incidentally, the position at which the main subject is photographed within the screen varies depending on the habits and preferences of the photographer, and also varies greatly depending on the photographing conditions.

Therefore, in such a focus detection device, for example,
Among the range-finding blocks shown in FIG. 3(b), for example, a photographer who frequently places the main subject in range-finding block A2 usually sets the range-finding block to A2. If you lend your camera to someone else and the camera is returned to you with a different AF block selected than AF block A2, and you notice that the AF block has changed when shooting, the operation to switch the AF block will be extremely difficult. This is a nuisance, and in some cases, there is a risk of missing a photo opportunity while switching the ranging block.

An object of the present invention is to enable distance measurement at a distance measurement position selected by the photographer from among a plurality of distance measurement positions on the screen, for example, a frequently used distance measurement position, so that other distance measurement positions can be used. It is an object of the present invention to provide a focus detection device that is capable of automatically performing distance measurement at a frequently used distance measurement position in the next photographing even if a photograph is taken at a certain position.

[Means for Solving the Problems] The gist of the present invention is to provide a distance measuring means for individually detecting the distance to a subject at a plurality of distance measuring positions within a screen; A distance measurement position selection means for selecting a distance measurement position, a storage means for storing the distance measurement position selected by the distance measurement position selection means, and a focal position determined by the distance measurement position stored in the storage means, and a photographing lens The focus detection apparatus is characterized by comprising: a control means for driving and controlling the driving means so as to match the focal position.

Further, a distance measuring means for individually detecting the distance to the subject at a plurality of distance measuring positions on the screen, a distance measuring position selection means for selecting the plurality of distance measuring positions, and a distance measuring means selected by the distance measuring position selecting means. A storage means for storing a distance measurement position, and a control means for determining a focal position based on the distance measurement position stored in the storage means and driving and controlling a photographic lens driving means to match the focal position, the control means The focus detection device is characterized in that, when the end of photographing is detected, the distance measurement position stored in the storage means is set as the distance measurement position for the next distance measurement.

Furthermore, a distance measuring means for individually detecting the distance to the subject at a plurality of distance measuring positions within the screen, a distance measuring position selection means for selecting the plurality of distance measuring positions, and a distance measuring means selected by the distance measuring position selecting means. a memory means for storing the distance measurement position; a timer means for operating a timer for a certain period of time when the distance measurement position is switched by the distance measurement position selection means; and control means for driving and controlling the photographing lens drive means to match the focus position, and when the control means detects the end of the operation of the timer means, it determines the distance measurement position stored in the storage means. A focus detection device is characterized in that the focus detection device is configured to be set as a distance measurement position in the next distance measurement.

[Function] The focus detection device configured as described above usually performs distance measurement at the memorized distance measurement position by storing distance measurement positions frequently used by the photographer in the storage means, and then the shooting ends. Then, even if distance measurement is performed at another distance measurement position,
The next shooting can be performed at the memorized ranging position, and even if a different ranging position from the memorized ranging position is selected, if the next shooting is not performed within a certain time, the memorized ranging position will be used. Make it accessible.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

FIG. 1 is a block diagram showing an embodiment of a focus detection device according to the present invention.

The focus detection device in this embodiment is as shown in FIG.
A, B, C, D on the camera screen.

E is equipped with a distance measurement system that detects the distance between subjects for five distance measurement points, 1 is a display unit that has a multi-point distance measurement point display section provided in the camera's finder, and 2 is a distance measurement sensor. , 3 is an A/D converter, 4 is a microprocessor unit, 5 is a camera release switch that instructs photometry and distance measurement operations when pressed halfway, and 6 changes data written in memory 9, which will be described later. 7 is a film feeding mode selector switch, 8a is a distance measurement point manual switch for selecting an arbitrary distance measurement point from the distance measurement points A to E in the above screen, and 8b is a memory A switch 9 inputs the distance measurement point selected by the distance measurement point input switch 8a (hereinafter referred to as a reference distance measurement point) to the memory switch 8.
10 is a lens drive unit that drives the photographing lens to the focus position, 11 is a position sensor that detects whether the camera is in the vertical or horizontal position, and the display In the unit 1, if the reference distance measurement point stored in the distance measurement point memory 9 is A in FIG. If the distance measurement point input switch 8a is off, no distance measurement point has been specified, and nothing has been input to the memory 9, the screen will be A distance measurement point C at the center of the target is set as a reference distance measurement point.

Furthermore, a horizontal position signal is input from the position sensor 11 to the MPU 4 when the camera is in the horizontal position, and a vertical position signal is input when the camera is in the vertical position.
When the reference distance measurement point is input by turning on a, and at the same time turning on the memory switch 8b, the vertical and horizontal position signals are stored together with the distance measurement point in the memory 9. When shooting, for example, if the camera is held vertically, , position sensor 11
detects that the camera is in the vertical position, and the MPU 4 reads the reference distance measurement point in the vertical position stored in the memory 9 when the distance measurement point input switch 8a is off.

Then, when the release switch 5 is pressed halfway to start the distance measurement sequence, the microprocessor unit 4 measures the point corresponding to the reference distance measurement point stored in the memory 9 or the automatically set distance measurement point C. Information from the light receiving element in the distance sensor 2 is read through the A/D converter 3, the day focus amount of the lens is calculated from this distance measurement data, and the lens drive unit 10 is controlled from this value to perform focus adjustment.

The operation of the focus detection device of this embodiment having the above configuration will be explained in the fourth section.
The process will be explained according to the flowcharts shown in FIGS.

FIG. 4 is a flowchart showing the basic operation of the MPU 4.

Before pressing the release switch 5 halfway, it is determined whether the reference distance measurement point is stored in the distance measurement point memory 9 based on whether the memory switch 8b is on or off. Here, if the photographer wants to store a specific distance measurement point on the screen in the memory 9, first select the desired distance measurement point from the distance measurement points A to H using the distance measurement point input switch 8a. , then memory switch 8
By turning on b, the selected ranging point is memorized. If you want to take a picture at the memorized ranging point, you can turn off the ranging point manual switch 8a, or set it to the selected ranging point position. However, if you want to take a picture at a distance measurement point other than the memorized distance measurement points, set the distance measurement point input switch 8a to that point.

When the release switch 5 is pressed halfway, it is determined whether the distance measurement point input switch 8a is on or off, and if it is on, the data of the distance measurement point input switch 8a is read, and the distance measurement sensor 2 corresponding to this distance measurement point is read. The image data from the light receiving element is read through the A/D converter 3, the day focus amount of the photographing lens is calculated from the image data, and the lens drive unit 10 is controlled based on this value to perform focus adjustment.

Then, when the shooting is finished, if the memory switch 8b is turned on and the shooting is performed at a different distance measuring point from the memorized distance measuring point, there is a risk that the contents of the memory will be changed. Memory switch 8
Turn off b.

On the other hand, when the ranging point input switch 8a is turned off, the data in the memory 9 is read out, and the image data from the light receiving element of the ranging sensor 2 corresponding to the memorized ranging point is passed through the A/D converter 3. The day focus amount of the photographing lens is calculated from the image data, and the lens drive unit 10 is controlled based on this value to perform focus adjustment. In this case, the distance measurement point is set by turning on the distance measurement point manual switch 8a, and then turning on the memory switch 8b.
Turn on and select any of the distance measuring points A to E on the screen that you selected and memorized, or press the distance measuring point input switch 8.
This is the distance measurement point C on the screen that is automatically selected when a is turned off from the beginning.

On the other hand, after the release, the distance measurement point is returned to the reference distance measurement point stored in the memory 9.

As shown in Fig. 5, this operation is performed when the shooting is completed.
The PU 4 receives the release signal and reads the distance measurement point data stored in the memory 9. If the memory 9 stores reference distance measurement points for each of the vertical and horizontal positions, for example, when shooting is completed in the horizontal position, the reference distance measurement point for this horizontal position is read and used for the next measurement. Use as a distance measurement point when measuring distance.

In addition, the camera position at the end of shooting is also memorized, and the next time the release switch 5 is pressed halfway, the camera position changes from r horizontal position to vertical position J or from r vertical position to horizontal position J. Switch to the reference distance measurement point for the subsequent camera position.

The reason why the distance measurement point is returned to the reference distance measurement point after photographing is completed is that the distance measurement point is more likely to be measured at the reference distance measurement point than the distance measurement point used this month in the next photographing.

On the other hand, if the ranging point is switched to a ranging point other than the reference ranging point, that is, if the ranging point is switched to a ranging point other than the ranging point stored in the memory 9, a certain amount of time will elapse after switching. Then, the distance measurement point returns to the reference distance measurement point.

In this operation, as shown in FIG. 6, when the distance measurement point input switch 8a is turned on, the MPU 4 receives a switching signal from the distance measurement point manual switch 8a and outputs a start signal to the timer circuit 6. The timer circuit 6, which started when the start signal was input, stops its operation after a certain period of time determined by various constants in the circuit, returns the stop signal to the MPU 4, and outputs a reset pulse to start the timer circuit 6 itself. Return to initial state. If the release switch 5 is turned off while this timer is operating, that is, if the release is not released even after a certain period of time has passed after changing the distance measurement point, it is determined that shooting with that framing has been stopped. , the data of the reference distance measurement point in the vertical or horizontal position is read from the memory 9 depending on the camera attitude at that time, and this data is used as the reference distance measurement point for the next distance measurement.

Also, if the release switch 5 is pressed during the timer operation to take a picture, that is, if the distance is measured and taken at a distance measurement point other than the standard distance measurement point, the shutter release will be delayed as in the case of the operation shown in Fig. 5. The data of the reference distance measurement point is read from the memory 9, and that distance measurement point is used as the distance measurement point for the next distance measurement.

Although omitted in the flowcharts of FIGS. 4 to 6, the release switch 5 is pressed during focus adjustment (AF) operation.
When it is turned off, it returns to the initial state (START).

[Effects of the Invention] As described above, according to the present invention, it is possible to perform distance measurement at a distance measurement position stored in the storage means according to the photographer's selection, and to perform distance measurement at a distance measurement position that is frequently used by the photographer. By storing the position, it is possible to eliminate the trouble of switching the ranging position to a frequently used ranging position and improve operability.

Also, the shooting at the distance measurement position stored in the storage means is completed,
When performing the next distance measurement, the distance measurement can be performed at the distance measurement position stored in the storage means, so unless the photographer has any particular intention to take pictures, the distance measurement can always be performed at the distance measurement position that is frequently used by the photographer. Can do distance.

Furthermore, even if you select a AF point that is different from the memorized AF point, if you do not intend to shoot at that AF point, the AF point will be measured at the memorized AF point. There is no need for troublesome operations such as going back and forth.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the focus detection device according to the present invention, FIG. 2 is a diagram showing distance measurement points in the finder screen, and FIG. 3(a) is a block diagram of a conventional focus detection device. FIG. 3(b) is a diagram showing ranging blocks that can be invited into the screen, and FIGS. 4, 5, and 6 are flowcharts. 1...Display unit 2...Distance sensor 3.
...A/D converter 4...Microprocessor unit (MPtl) 5.
...Release switch 6...Timer circuit 8a...
- Distance measurement point input switch 8b...Memory switch 9...Distance measurement point memory 10...Lens drive unit 11...Position sensor Figure 1. Figure 2 Figure 3 □ A2 AI A3 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. A distance measuring means for individually detecting the distance to a subject at a plurality of distance measuring positions within a screen, a distance measuring position selection means for selecting the plurality of distance measuring positions, and a distance measuring means for selecting the plurality of distance measuring positions; A storage means for storing the distance measurement position selected by the selection means, and a control means for determining the focal position based on the distance measurement position stored in the storage means and driving and controlling the photographic lens driving means so as to match the focal position. A focus detection device comprising: 2. A distance measuring means that individually detects the distance to the subject at a plurality of distance measuring positions within the screen, a distance measuring position selection means that selects the plurality of distance measuring positions, and a distance measuring means that selects the distance measuring position selected by the distance measuring position selecting means. comprising a storage means for storing a distance position, and a control means for determining a focal position based on the distance measurement position stored in the storage means and driving and controlling a photographic lens driving means so as to match the focal position;
A focus detection device characterized in that, when the control means detects the end of photographing, it sets the distance measurement position stored in the storage means as the distance measurement position for the next distance measurement. 3. A distance measuring means that individually detects the distance to the subject at a plurality of distance measuring positions within the screen, a distance measuring position selection means that selects the plurality of distance measuring positions, and a distance measuring means that selects the distance measuring position selected by the distance measuring position selecting means. a memory means for storing the distance position; a timer means for operating a timer for a certain period of time when the distance measurement position is switched by the distance measurement position selection means; and a focal point position determined by the distance measurement position stored in the storage means. and control means for driving and controlling the photographic lens drive means to match the focal position, and when the control means detects the end of the operation of the timer means, it moves the distance measurement position stored in the storage means to the next one. 1. A focus detection device configured to be set as a distance measurement position in distance measurement.