KR102089977B1 - Assist light projection apparatus, Flash apparatus, and Photographing apparatus - Google Patents

Abstract

A technique for improving robustness against a change in a focal length of a pattern for autofocus detection, wherein the auxiliary light projection unit 32 (auxiliary light projection device) is a camera equipped with a focus detection unit 16 (autofocus detection device) (10) It is mounted on the (imaging device), and the focus detection unit 16 projects the pattern P for auto focus detection onto the subject F as an auxiliary light in order to perform auto focus detection. The pattern P for autofocus detection includes a rough pattern area Pr, a heavy pattern area Pm denser than the rough pattern area Pr, and a wheat pattern area Pc denser than the heavy pattern area Pm. In the pattern P for autofocus detection, the center coordinates (prc) of the jaw pattern area Pr and the center coordinates (pmc) of the middle pattern area Pm and the center coordinates (pcc) of the mill pattern area Pc are the cameras. In consideration of the parallax between the photographing lens 20 (imaging optical system) of (10) and the projection system of the auxiliary light projection unit 32, they are separated from each other.

Description

Assist light projection apparatus, flash apparatus, and photographing apparatus

The present invention relates to an auxiliary light projection device, a flash device, and a camera.

As a technique related to the present invention, Japanese Patent Application Publication No. 2010-008689 is mounted or embedded in a camera equipped with an auto focus detection device, and projects a pattern for focus detection as an auxiliary light onto a subject, and a pattern for focus detection reflected from the subject Disclosed is an auxiliary light projection device that detects an autofocus detection device.

This focus detection pattern becomes dense in the vicinity of the center of the photographing screen, and sparsely in other areas. As a result, even when a wide-angle lens or a telephoto lens is used, it is possible to properly adjust the relationship between the auto-focusing area and the pattern for focus detection, so that auto-focus detection is always performed accurately.

However, since the auxiliary light projection apparatus is disposed at a position away from the photographing lens, the range area in the focus detection pattern moves according to the focal length. Therefore, when the focus detection pattern of the above-mentioned patent document is employed, when the focal length is large, the center of the distance measurement area deviates from the dense region of the focus detection pattern. As a result, the degree of automatic focus detection by auxiliary light projection may not be sufficiently secured.

The present invention relates to providing a technique capable of improving robustness (robustness) to a change in the focal length of a pattern for automatic focus detection.

According to the first aspect of the present invention, an auxiliary light projection that is mounted on or built in an imaging device having an autofocus detection device and that the autofocus detection device projects an autofocus detection pattern as an auxiliary light on an object to perform autofocus detection In the apparatus, the pattern for autofocus detection includes a rough pattern region, a wheat pattern region denser than the rough pattern region, and in the autofocus detection pattern, a center coordinate of the rough pattern region and a center of the mill pattern region Coordinates may be provided with a separate auxiliary light projection device in consideration of the parallax between the imaging optical system of the imaging device and the projection system of the auxiliary light projection device.

According to the second aspect of the present invention, an auxiliary light that is mounted on or embedded in an imaging device equipped with an autofocus detection device, and the autofocus detection device projects an autofocus detection pattern onto a subject as an auxiliary light for performing autofocus detection. In the projection apparatus, the pattern for auto focus detection includes a rough pattern region, a heavy pattern region denser than the rough pattern region, and a dense pattern region denser than the heavy pattern region, and in the auto focus detection pattern. , The center coordinates of the rough pattern area, the center coordinates of the middle pattern area, and the center coordinates of the mill pattern area are auxiliary lights spaced apart from each other in consideration of the parallax between the imaging optical system of the imaging device and the projection system of the auxiliary light projection device. A projection device can be provided.

According to a third aspect of the present invention, in a scintillation device mounted on the imaging device and emitting flash based on an operation instruction of the imaging device, a scintillation device equipped with the auxiliary light projection device may be provided.

According to the fourth aspect of the present invention, an imaging device equipped with the auxiliary light projection device can be provided.

Advantageous Effects of Invention According to the present invention, robustness against a change in a focal length of a pattern for automatic focus detection is improved.

1 is a functional block diagram of a camera equipped with a flash device;
2 is a front view of a camera equipped with a flash device;
3 is a pattern for auto focus detection according to an embodiment of the present invention;
4 is a plan view image of a zoomed view toward the wide-angle side;
Fig. 5 is an image of the shape of the subject from the projection system when zoomed to the wide-angle side;
6 is a plan view image of a zoomed view toward the telephoto side;
Fig. 7 is an image of the shape of the subject from the projection system when zoomed to the telephoto side;
8 is a front view of a camera incorporating an auxiliary light projection.

Hereinafter, embodiments of the auxiliary light projection apparatus, the scintillation apparatus, and the imaging apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

It should be understood that the embodiments described below are illustratively shown to help the understanding of the present invention, and the present invention can be implemented in various ways different from the embodiments described herein. However, in the following description of the present invention, when it is determined that a detailed description of related known functions or components may unnecessarily obscure the subject matter of the present invention, the detailed description and specific illustration will be omitted. In addition, the accompanying drawings may not be drawn to scale in order to aid the understanding of the invention, but the dimensions of some components may be exaggerated.

In FIG. 1, the camera (imaging apparatus) 10 may be, for example, a single lens reflex camera configured to be detachably attached to the imaging lens 20 which is an imaging optical system. Further, the camera 10 may be a compact digital camera instead of a single-lens left camera. The camera 10 includes a quick-return mirror 11, a sub-mirror 12, a shutter 13, an imaging device 14, a lens mounting unit 15, a focus detection unit (automatic focus detection device) ( 16), a Central Processing Unit (CPU) 17, and a hot shoe 18.

The shooting lens 20 is detachable to the camera 10 through the lens mounting unit 15, and a telephoto lens with a long focal length, a wide-angle lens with a short focal length, or a zoom lens with a variable focal length can be mounted. have. In the following description, the wide-angle lens and the telephoto lens include the wide-angle side and the telephoto side of the zoom lens.

The lens mounting portion 15 is provided with a contact portion 15a that can be electrically connected to a contact portion 20a provided on the photographing lens 20 side.

The flash device 30 is a flash device attached to the outside in this embodiment, and is attached to the camera 10 through a hot shoe 18 that is a synchro contact. This scintillation device 30 is sold in connection with the camera 10. The flash device 30 may be a dedicated product of the camera 10 or a common product used for a plurality of cameras including the camera 10. The scintillation device 30 includes a light emitting unit 31 that emits flash to illuminate a subject during shooting, and an auxiliary light projection unit that projects an auxiliary light autofocus detection pattern P (see FIG. 3) (see auxiliary light projection). Device) 32, and a CPU 33.

As shown in FIG. 2, in this embodiment, the flash device 30 is mounted on the upper left of the photographing lens 20 when viewed from the front of the camera 10. Therefore, the auxiliary light projection unit 32 is positioned at the upper left of the photographing lens 20 when viewed from the front of the camera 10.

In the above configuration, the light of the object incident through the photographing lens 20 is divided into a finder system and a focus detection system, which are not shown in the quick return mirror 11. Among them, the light directed to the finder system is led to a finder unit (not shown), which is seen by the photographer through an optical system such as a finder screen, a pentaprism, and an eyepiece, for example. On the other hand, the light directed to the focus detection system passes through the quick return mirror 11 and is reflected by the sub-mirror 12 to enter the focus detection unit 16.

Thus, while the photographer presses the release button not shown halfway while looking at the subject image displayed on the finder unit, the focus detection unit 16 automatically or automatically selects the subject light incident on the selected non-illustrated range area. Focus is detected, and the focus is adjusted by driving the photographing lens 20 through the contact portion 15a and the contact portion 20a based on the focus detection information.

In addition, information about luminance or contrast of the subject light incident on the focus detection unit 16, information about an automatically or manually selected range area, etc. is transmitted to the CPU 17.

When the CPU 17 determines that the luminance or contrast of the subject is low, an operation instruction signal is sent to the CPU 33 of the flash device 30, and the pattern P for autofocus detection from the auxiliary light projection unit 32 toward the subject ). The focus detection unit 16 detects the auto focus detection pattern P reflected from the subject and automatically performs focus detection as described above, and drives the photographing lens 20 based on this focus detection information to adjust the focus Do it.

In addition, the CPU 33 of the scintillation device 30 may perform the determination as to whether or not the luminance or contrast of the subject is low.

Thus, when the release button (not shown) is pressed by the photographer, the CPU 17 moves the quick return mirror 11 and the sub-mirror 12 off the shooting light path to open the shutter 13. Thereby, the image of the object formed by the photographing lens 20 is imaged by a photographing element 14 composed of, for example, a CCD or CMOS, and an image can be acquired.

Next, with reference to FIG. 3, the pattern P for autofocus detection according to this embodiment will be described in detail.

As shown in FIG. 3, the pattern P for autofocus detection includes a rough pattern area Pr, a middle pattern area Pm, and a wheat pattern area Pc. It is done. The middle pattern area Pm is a pattern for autofocus detection in which the pattern of the pattern is denser (the interval between the pattern patterns is narrower) than the rough pattern area Pr. The wheat pattern area Pc is a pattern for autofocus detection in which the pattern of the pattern is denser (the interval between the pattern patterns is narrower) than the middle pattern area Pm. The middle pattern region Pm is disposed in an overlapping shape inside the jaw pattern region Pr. The wheat pattern area Pc is disposed in an overlapping form inside the middle pattern area Pm.

In FIG. 3, the outline pr of the jaw pattern region Pr is a virtual line drawn for convenience of description so that the outline of the jaw pattern region Pr can be easily grasped. Similarly, the outline (pm) of the middle pattern area (Pm) is a virtual line drawn for convenience of description so that the outline of the middle pattern area (Pm) can be easily grasped. Similarly, the outline (pc) of the wheat pattern area (Pc) is a virtual line drawn for convenience of explanation so that the outline of the wheat pattern area (Pc) can be easily grasped.

Here, the center coordinates prc of the jaw pattern region Pr are the center coordinates of the jaw pattern region Pr determined based on the outline pr of the jaw pattern region Pr. In this embodiment, since the outline pr of the jaw pattern area Pr is square, the center coordinate prc is determined as the coordinate of the intersection of two diagonals of the square.

Similarly, the center coordinates pmc of the middle pattern area Pm are the center coordinates of the middle pattern area Pm determined based on the outline pm of the middle pattern area Pm. In this embodiment, since the outline (pm) of the middle pattern area Pm is a parallelogram, its center coordinate pmc is determined as the coordinate of the intersection of two diagonals of the parallelogram.

Similarly, the center coordinates pcc of the wheat pattern area Pc are the center coordinates of the wheat pattern area Pc determined based on the outline pc of the wheat pattern area Pc. In this embodiment, since the outline (pc) of the wheat pattern area Pc is a parallelogram, the center coordinate pcc is determined as the coordinate of the intersection of two diagonals of the parallelogram.

In FIG. 3, an epipolar line E, which is determined based on the parallax between the imaging lens (imaging optical system) 20 of the camera 10 and the projection system of the auxiliary light projection unit 32, is drawn. The epipolar line E is a line corresponding to the optical axis of the photographing lens 20 of the camera 10 in the pattern P for autofocus detection.

Thus, in this embodiment, in the pattern P for autofocus detection, the center coordinates prc of the rough pattern area Pr, the center coordinates pmc of the middle pattern area Pm, and the mill pattern area Pc The center coordinates pcc are separated in consideration of the parallax between the imaging lens (imaging optical system) 20 of the camera 10 and the projection system of the auxiliary light projection unit 32. Thus, in the pattern P for autofocus detection, the middle pattern area Pm and the wheat pattern area Pc are arranged elongately along the epipolar line E. In addition, in the pattern P for autofocus detection, the center coordinates pmc of the middle pattern area Pm and the center coordinates pcc of the mill pattern area Pc are located near the epipolar line E. Specifically, in the pattern P for autofocus detection, the center coordinates pmc of the middle pattern area Pm and the center coordinates pcc of the wheat pattern area Pc are located on the epipolar line E. The center coordinates (prc) of the rough pattern area Pr, the center coordinates (pmc) of the middle pattern area Pm, and the center coordinates (pcc) of the mill pattern area Pc in this order are the patterns P for autofocus detection. ) On the epipolar line E toward the upper right side.

According to the pattern P for autofocus detection as described above, the robustness against a change in the focal length of the pattern P for autofocus detection is improved. That is, even when the focal length changes, it is possible to perform autofocus adjustment using the pattern P for autofocus detection. The reason will be described in detail below with reference to FIGS. 3 to 7 attached.

4 and 6 show the subject F. As shown in Fig. 4, when the subject F is photographed from the wide-angle side, as shown in Fig. 5, a range (Q) that effectively functions in autofocus detection among the patterns P for autofocus detection ) (Corresponding to the measurement area) is approximately equal to the entirety of the pattern P for autofocus detection, and the center of the range Q is approximately the same as the center of the pattern P for autofocus detection.

On the other hand, as shown in Fig. 6, when the subject F is imaged from the telephoto side, as shown in Fig. 7, the autofocus detection pattern P effectively functions in autofocus detection. The range Q becomes a narrow area at the upper right of the pattern P for autofocus detection.

  As described above, the range Q effective in autofocus detection among the patterns P for autofocus detection moves without being fixed according to a change in the focal length of the photographing lens 20. As a result, an appropriate pattern resolution and pattern position (position of the range Q) as the pattern P for autofocus detection changes according to the focal length of the photographing lens 20.

In the autofocus detection pattern P, when referring to the movement direction of the range Q that effectively functions in autofocus detection, the auxiliary light projection 32 in the front view shown in FIG. 2 is the left side of the photographing lens 20 When placed above, the range (Q) is (a) the telephoto detection pattern (P) moves to the upper right as it becomes telephoto, and (b) the wide-angle autofocus detection pattern (P) of the Move to the bottom left. Thus, in this case, as shown in FIG. 3, the pattern P for auto focus detection becomes high resolution toward the upper right direction of the pattern P for auto focus detection, and the pattern P for auto focus detection is It is preferable that the pattern P for auto focus detection toward the lower left direction becomes a low resolution.

If, in the front view shown in Fig. 2, when the auxiliary light projection 32 is disposed on the upper right of the photographing lens 20, the range Q is (a) a telephoto pattern for automatic focus detection as it becomes telephoto ) Moves to the upper left, and (b) moves to the lower right of the pattern P for autofocus detection as it becomes wide angle. Therefore, in this case, the pattern P for autofocus detection becomes high resolution toward the upper left direction of the pattern P for autofocus detection, and autofocus detection toward the lower right direction of the pattern P for autofocus detection. It is preferable that the dragon pattern P becomes a low resolution.

Thus, in consideration of the movement of the range (Q) (faring area) on the epipolar line E according to the focal length at the time of autofocus detection, the mill pattern area Pc or the medium pattern area Pm in FIG. ) Along the epipolar line E, that is, the center coordinates pcc of the mill pattern area Pc and the center coordinates pmc of the middle pattern area Pm are near the epipolar line E, Preferably, by arranging on the epipolar line E, it is possible to enlarge the portion to be enlarged at a pinpoint when zooming to the telephoto side. As a result, robustness to a change in the focal length of the pattern P for autofocus detection is improved.

That is, according to the embodiment according to the present invention, in consideration of the optical arrangement of the imaging optical system and the auxiliary light projection optical system for autofocus in advance, a pattern having a high resolution is planted only in the portion to be enlarged when zoomed. Then, when the imaging optical system is zoomed, the pattern for autofocus detection of the normal resolution before zooming becomes too large to be used as a pattern for autofocus detection, but a pattern with a high resolution near the epipolar line E is automatically It can be effectively used as a pattern for focus detection. Therefore, according to the present invention, since the resolution of the pattern P for autofocus detection is appropriately changed according to the change in the focal length, autofocus detection can be easily performed regardless of the change in the focal length.

The preferred embodiment of the present invention has been described above, but the above-described embodiment has the following advantages.

The auxiliary light projection unit 32 (auxiliary light projection apparatus) is mounted on the camera 10 (shooting apparatus) equipped with the focus detection unit 16 (autofocus detection apparatus), so that the focus detection unit 16 performs automatic focus detection As an auxiliary light for this, the auto focus detection pattern P is projected onto the subject F. The pattern P for autofocus detection includes a rough pattern area Pr, a heavy pattern area Pm denser than the rough pattern area Pr, and a wheat pattern area Pc denser than the heavy pattern area Pm. . In the pattern P for autofocus detection, the center coordinates (prc) of the jaw pattern region Pr, the center coordinates (pmc) of the middle pattern region Pm, and the center coordinates (pcc) of the mill pattern region Pc are Considering the parallax between the imaging lens 20 (imaging optical system) of the camera 10 and the projection system of the auxiliary light projection unit 32, they are separated from each other. According to such a structure, the pattern P for autofocus detection in response to the movement of the range area accompanying the change in the focal length of the photographing lens 20 can be realized. As a result, robustness to a change in the focal length of the pattern P for autofocus detection is improved.

In the pattern P for autofocus detection, the middle pattern area Pm and the wheat pattern area Pc are arranged elongately along the epipolar line E determined based on the parallax. According to such a structure, the pattern P for autofocus detection reflecting the movement of the range area accompanying the change in the focal length of the photographing lens 20 can be realized.

In the pattern P for autofocus detection, the center coordinates pmc of the middle pattern area Pm and the center coordinates pcc of the mill pattern area Pc are near the epipolar line E determined based on the parallax. Is located in According to this configuration, the pattern P for autofocus detection that strongly reflects the movement of the range area accompanying the change in the focal length of the photographing lens 20 can be realized.

In the above, although the preferred embodiment of the present invention has been described, the auxiliary light projection unit 32 may be embedded in the camera 10 as shown in FIG. 8.

In addition, in the above description, although the vertical stripe is described as an example of the pattern P for autofocus detection, the shape of the pattern P for autofocus detection is not limited thereto.

In addition, in the above description, the pattern P for autofocus detection is formed by overlapping patterns having three resolutions, that is, the rough pattern region Pr, the middle pattern region Pm, and the wheat pattern region Pc, In other words, the structure pattern having the middle pattern area Pm inside the jaw pattern area Pr and the mill pattern area Pc inside the middle pattern area Pm is described as an example, but for automatic focus detection. The pattern P is not limited to this. The pattern P for autofocus detection used in the auxiliary light projection apparatus according to an embodiment of the present invention may be formed by overlapping patterns of the same shape having two different resolutions or four or more different resolutions.

10; camera
20; Shooting lens
32; Auxiliary light projection
P; Auto focus detection pattern
Pr; Joe pattern area
Pm; Medium pattern area
Pc; Wheat pattern sphere
prc; Center coordinates
pmc; Center coordinates
pcc; Center coordinates
E; Epipolar Line
Q; range
F; Subject

Claims (12)

In the auxiliary light projection device mounted or embedded in an imaging device having a quick return mirror and an auto focus detection device, the auto focus detection device projects an auto focus detection pattern as an auxiliary light for performing auto focus detection to a subject,
The auto focus detection pattern includes a rough pattern region and a dense pattern region denser than the rough pattern region,
In the auto focus detection pattern, the center coordinates of the rough pattern area and the center coordinates of the dense pattern area are separated in consideration of the parallax between the imaging optical system of the imaging device and the projection system of the auxiliary light projection device. Auxiliary light projection device. According to claim 1,
In the pattern for auto focus detection, the dense pattern area is arranged in an elongated shape along an epipolar line determined based on the parallax. According to claim 1,
In the pattern for auto focus detection, the center coordinates of the dense pattern region are located near an epipolar line determined based on the parallax, and the auxiliary light projection apparatus. In the auxiliary light projection device mounted on or built in an imaging device having a quick return mirror and an auto focus detection device, the auto focus detection device projects an auto focus detection pattern onto a subject as an auxiliary light for performing auto focus detection,
The pattern for autofocus detection includes a rough pattern region, a heavy pattern region denser than the rough pattern region, and a dense pattern region denser than the heavy pattern region,
In the pattern for autofocus detection, the center coordinates of the rough pattern area, the center coordinates of the middle pattern area, and the center coordinates of the mill pattern area indicate the parallax between the imaging optical system of the imaging device and the projection system of the auxiliary light projection device. Auxiliary light projection device, characterized in that apart from consideration. The method of claim 4,
In the auto-focus detection pattern, the auxiliary pattern projection apparatus characterized in that the middle pattern area and the wheat pattern area are arranged elongately along an epipolar line determined based on the parallax. The method of claim 4,
In the automatic focus detection pattern, the center coordinates of the middle pattern area and the center coordinates of the wheat pattern area are located near an epipolar line determined based on the parallax. A scintillation device mounted on an imaging device and emitting light based on an operation instruction of the imaging device,
Claim 1 to claim 6, wherein any one of the auxiliary light projection device; flash device comprising a. Claim 1 to claim 6, wherein any one of the auxiliary light projection apparatus; Imaging apparatus comprising a. An imaging device including a quick return mirror and an automatic focus detection device;
A photographing lens installed on the front surface of the imaging device; And
It includes a scintillation device that is installed on the imaging device to the upper right of the photographing lens, and includes an auxiliary light projection device that projects an auto focus detection pattern onto an object as an auxiliary light so that the auto focus detection device automatically detects focus. ,
The pattern for autofocus detection includes a rough pattern region, a heavy pattern region denser than the rough pattern region, and a dense pattern region denser than the heavy pattern region,
The middle pattern region is located inside the rough pattern region, and the wheat pattern region is located inside the middle pattern region,
The center coordinates of the rough pattern region, the center coordinates of the middle pattern region, and the center coordinates of the mill pattern region are separated from each other in consideration of the parallax between the imaging optical system of the imaging device and the projection system of the auxiliary light projection device. Image pickup device. The method of claim 9,
In the auto focus detection pattern, the middle pattern area and the wheat pattern area are arranged elongately along an epipolar line determined based on the parallax. The method of claim 9,
In the pattern for autofocus detection, the center coordinates of the middle pattern area and the center coordinates of the wheat pattern area are located near an epipolar line determined based on the parallax. The method of claim 11,
The epipolar line is an imaging device, characterized in that the straight line is inclined in the upper right direction to the auto focus detection pattern.

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