JPS58171025A - Photographing device - Google Patents

Abstract

PURPOSE:To simplify range finding visual-field display in a viewfinder and to improve the precision f range finding, by allowing a means for focus adjustment to include a means which hold a range finding visual field in the center of a viewfinder image plane. CONSTITUTION:Light from a projecting element 1 is caused to strike an object and its reflected light is image-formed on a photodetecting element 3 to perform the focusing of a photographic lens system 5. In this case, the rotating shafts 16 and 18 of a projecting element holder 15 and a photodetecting element holder 17 are arranged at right angles to the straight line connecting the center of the projecting element 1 and that of the photodetecting element 3 to each other and a scan on both elements is made toward the center of a photographic lens 5, so the range finding visual field is positioned in the center of the image plane all the time. Therefore, nearly accurate range finding visual-field information is obtained by only two range finding visual-field marks in the viewfinder corresponding to the longest focal length and shortest focal length.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that the display in the finder of a photographing device KfllL such as a camera, particularly a photographing device having 41 automatic focus adjustment positions, is made simple.

Many proposals have been made regarding automatic focusing devices for cameras including video cameras, 8-inch cameras, and still cameras, and most of these are based on the principle of triangulation.

By the way, this automatic focusing device using the trigonometric distance method has 5
When used with a 5-point resteal camera, etc., even when the baseline length is sufficient, the movement of the distance measurement position on the viewfinder screen is at a level that allows for a complete view, but mainly when used with an 8 mm camera or video camera. When using a high-magnification lens on a camera that smells, the effect of parallax is large due to two reasons: the zero-high magnification of the lens and the long rounding baseline length when using a high-magnification lens. (The projected light spot image 06 inside is so dead that it cannot be ignored), which reduces the accuracy of distance measurement. Furthermore, when installing this type of dynamic focusing system into an actual 8mm camera or video camera, etc.

The ninth step in distance measurement, for example, is often done by shifting the optical axes of the light emitting and receiving lenses from the center of the photographing lens and arranging them in an offset manner. ) is displaced from the vertical direction to a certain angle tiii diagonal direction, 〉, which causes a decrease in distance accuracy.

On the other hand, if it is possible to keep the distance measurement field at the center of the finder screen, the distance measurement accuracy can be reduced to 11@h.
However, it is difficult to make the distance measurement field display on the finder K simple to 111.

Therefore, it is an object of the present invention to provide a photographing device having an automatic focus adjustment device using triangulation distance measurement, and to provide a means for always maintaining the distance measurement field at the center of the finder screen, and 1. To provide a photographing device which can simplify the distance measurement range display in a finder, further improve the Km distance accuracy, and can be configured to the minimum necessary size.

To summarize, the present invention uses a photographic optical system (a photographic lens system in a specific example described later), a first and second element (also a light emitting element and a light receiving element), and the first and li2 elements. Means for adjusting the focus of a shooting optical system on a subject; and 1 when using the image manipulation optical system at a long focal length.
Display of 11m field of view (also distance measurement field mark) and I[%A
When used at focal length, it is characterized by displaying 0 distance measurement field of view.

Hereinafter, the present invention will be described with reference to the drawings, and nine concrete sequences will be described. FIG. 1 shows an automatic focusing device to which the present invention is applied, and numeral 1 represents a light projecting element, such as an infrared light emitting diode (IRVD) or a laser diode.

2 is a light projecting lens, and the light projecting element 1 is based on this lens)
A projection spora) Im is formed on the side of the object.

When nine beams of light are emitted from the light projecting element 1) and hit the subject, they are diffusely reflected, and the light projecting spora (Im) on the subject surface is imaged onto the light receiving element S by the light receiving lens 4).

The light-receiving element 5 may be, for example, a photodiode that can be divided into two areas and output an output from each area, or a round element that has two fluorescent elements arranged close to each other. The final position above is when the subject distance is 11th.
As shown in Fig. 1, the light emitting spot on the subject changes as it changes to s/1 m12.1B, so information indicating the distance to the subject is given by the position of the light emitting spot on the subject and the position on the light receiving element. In the example shown in Figure 1, if the two regions of the photodetector +3 are called the mu region and the B region, then the position of the photodetector is changed so that the difference in output between the regions is mu -B-Q. ing. 811, 5 is a lens group that performs a focusing operation in the photographing lens system, 4 is a camera tube, and the light emitting element 1, the light receiving element 5, and the lens group 5 are, for example, a cam mechanism as shown in the figure. It is linked to. In this way, it is possible to measure the distance to the subject and automatically adjust the focus.Furthermore, if the light emitting element is emitted continuously or in pulses at short intervals, it is possible to easily adjust the distance to the object. Continuous focusing becomes possible.

In FIG. 1, when the optical axes of the photographing lens 5, the light emitting lens 2, and the light receiving lens 4 are on the same plane, and the focal lengths of the light emitting lens and the light receiving lens are the same,
By moving the light emitting element 1 and the light receiving element 5 by the same distance in opposite directions within the above plane, the position of the distance measuring field can be changed.
As shown in Figure 2, the lens can be kept at the center of the viewfinder plane at all times. #! In figure 2, fruit 4 [
i19 indicates the distance measurement position when the focal length of the photographing lens is W1, and the chain double-dashed line 2o indicates the distance measurement position when this is a problem. Similarly, when the photographic lens is a zoom lens, the distance measurement position continuously changes between the shortest focal length and the longest focal length of the zoom lens.

In this invention, however, as shown in FIG. A display 22 corresponding to the case will be provided. As a result, almost accurate ranging field information can be obtained using only these two types of displays.

However, as shown in FIG. 4, in an actual camera, due to the arrangement of other operating members, for example, the operating member for zooming, the photographic lens 5 and the light emitting lens 2 are It is rather rare that the optical axes of the three lenses exist on the same plane; for example, as shown in the figure, the light projecting lens 2 and the light receiving lens 4 must be offset from the center of the photographing lens 5. In other words, Figures 11N4 (M) and (I) are examples in which an automatic focus adjustment device using the triangular lateral pressure method is incorporated into an actual 8-zoom camera or video camera, and 14 is an operation for performing manual zooming. The bar is a bar, and a indicates its rotation range.For example, when the user grips the grip 12 with his right hand and operates the trigger lens 13, he also performs manual zooming with his left hand. In order to avoid covering the front part of the light receiving lens 4 with the left hand, it is recommended that the light receiving lens 4 be placed offset from the center of the photographing lens 5 as shown in FIG. Figure 5 shows the distance measurement position in the finder screen, that is, the displacement of the position of the projected light spot image when focusing is performed by scanning only one of the light emitting and receiving optical systems (for example, by scanning only the light receiving system). As shown. In other words, if the distance measurement position (projection spot image) is 8-1 at a certain distance with respect to the entire screen 7, for example, the subject is closer than the distance corresponding to 8-1.
What if it's at 1? -IK, 10-1 when in long distance
The distance measurement position changes as follows. The relationship between motoyo, clay, and clay changes depending on the arrangement of the light emitting and receiving elements. Sara K
If this photographic lens system is a zoom lens, the focal length is 1
1, the size of the projected light spot within the screen changes according to 8-2, 9-2 and 10-2 in FIG.
It becomes large like 0. Furthermore, as can be seen from Figure 5, the change in the position of the light emitting slot [1! Direction or! It occurs along the 9B direction, not in either direction, but at a certain angle from the I axis. According to the inventor's analysis, this phenomenon is caused by a displacement component in the I-axis direction (if the O-projection/reception optical system is placed offset from the center of the photographic lens), and only the optical system on one side of the trench is disposed. When you scan it, it's K)! A displacement component in the axial direction is generated, and the combination of both causes displacement in the ON direction shown in the figure. Even in the offset arrangement as shown in FIG. 4, if the light emitting/receiving optical system is scanned symmetrically, the distance measurement position will be displaced by 4 in the Y-axis direction.

Desirable embodiment of this inventionIIIAIl! As mentioned above, even when the optical axes of the photographing lens, light emitting lens, and light receiving lens are not on the same plane, the distance measurement field of view is prevented from shifting.
This allows the position to be always maintained at the center of the screen, and the key point is to connect the optical axes of the light emitting optical system and the light receiving optical system to the optical axis of the photographing optical system and the respective optical axes. There is a K that allows simultaneous movement around one axis of rotation in a direction perpendicular to the direct dK. An example in which both the light projecting element of the light projecting optical system and the light receiving element of the light receiving optical system are rotated will be specifically described below.

FIG. 6 shows the scanning direction of the light projecting and receiving system according to the present invention,
The direction of the rotation axis 14 of the light projecting element holder 15 is arranged perpendicular to the center of the light projecting element 1, that is, the straight line connecting the center of the light projecting lens and the center of the photographing lens. In general, the above objective can be achieved as long as the direction of the rotation axis 16 is perpendicular to the straight line connecting the lens cap of the projecting lens and the optical axis of the projection lens. Similarly, the direction of the rotation axis 18 of the light receiving element holder 17 is arranged perpendicular to the straight line connecting the optical axis of the light receiving element and the optical axis of the photographing lens.

The light emitting element and the light receiving element are rotated about one wheel 14 and 11, respectively, and scanning is performed in a direction perpendicular to the plane of the paper in FIG. 6. According to this configuration, as described above, since the direction of the basin of the light emitting element and the light receiving element is directed toward the center of the photographing lens, the optical axes of the photographing lens, the light emitting lens, and the light receiving lens are aligned on the same plane. To make it possible to always position a distance measurement field of view at the center of a screen even when the distance measurement is difficult. In this case, the condition of the finder screen is as shown in Figure 2 [fk], even if the optical axes of the s optical systems are not on the same plane, the distance measuring radius is always placed at the center of the screen. be able to. Therefore, in this case as well, as in Figure 5 above, the distance measurement field mark in the finder corresponds to the longest focal length of the photographing lens.
Display 21 that corresponds to the shortest time, and Display 2 that corresponds to the shortest time.
By simply providing 2, it is possible to obtain highly accurate ranging field information. When the photographic lens system is an interchangeable lens system, display 21 is set for a lens system with a short zero point distance, while display 22 is set for a lens system with a short zero point distance.
A similar effect can be achieved by making them correspond.

In the above specific example, it is assumed that the focal lengths of the light emitting lens and the light receiving lens are the same, but if they are different, the light emitting element and the light receiving element are made to draw a trajectory that matches the focal length. A similar effect can be achieved if the light emitting element or the light receiving element is sharpened. Any device that can emit or receive a spot image
f, *Great people are not necessarily essential.

The above explanation is based on the present invention, in which the light receiving element is divided into two regions, and the differential sensor which provides information indicating the distance to the subject (by the output of the module B) is used. In addition, this invention can also be applied to a type 4 type that utilizes the peak output from a light-receiving element.
Not only the III distance@*, but also a passive distance measuring device ftK can be applied.

Each of the first and second elements in this invention may be a plurality of element groups.

This invention has the above-mentioned structure and operation, and based on this, the distance measuring radial bone can be rounded even when the optical axes of the two optical systems are not on the same plane. You can always keep the viewfinder at the center of the screen, and this allows you to see almost accurate distance viewing by simply experiencing the display when the focal length of the photographic lens is long and the display when it is short. Radius can be obtained.

By these means, it is possible to improve m distance accuracy and configure the photographing device to the minimum necessary size.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing an example of an automatic focus adjustment device to which this invention is applied, Figure 2 is a diagram showing the rangefinding field position when using the 11F) device, and Figure 1 is a diagram showing the distance measurement field position when using the device. Figure shown, No. 4! Fa (mu) is a front view showing an example of incorporating an automatic focus adjustment device into a camera, FIG. 4 (B) is a side view of FIG. 4 (mu), and t! FIG. 45 is a diagram showing the distance measuring field of view position when using the apparatus of FIGS. In the figure, 1 is a light emitting element, 2 is a light emitting lens, S is a light receiving element, 4
1 is a light-receiving lens; 15 is a light-emitting element holder; 16 is a rotation axis of the light-emitting element; 17 is a light-receiving element holder; 18 is a rotation axis of the light-receiving element; 21 and 22 is the distance measurement field mark. ¥30 x ¥4 [7 (A) Male 47 (8)

Claims (1)

[Claims] (1) A photographing optical system. 111117! an IL and a second element; means for adjusting the focus of the imaging optical system on a subject using these 1111 and 20th elements; The photographing device is equipped with a display and a viewfinder with a 0I11 distance field when used with a short focal length. (2) The OAIS device according to claim (1), wherein the means for adjusting the focus includes means for holding sg@** at the center of the fine image. (S) When the photographing optical system is a lens system with a narrow focal length, and the viewfinder uses a ζO and y-axis system at the longest point of view, the viewing angle is 0Ilili O1! Indication and amount%
9. The imaging device according to claim (1), further comprising a display of a distance measuring radius when used at a focal length of 411/%. (4) The photographing optical system is an interchangeable lens system, and the finder has a distance measuring radial display corresponding to a lens system with a long hot spot distance and a distance measuring radius corresponding to a lens system with a short focal length. The imaging device according to claim (1), further comprising a radius bone display.