JP2004165841A - Auxiliary light projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an auxiliary light projector with a simple configuration for projecting an automatic focus detecting pattern of various shapes having a high contrast over a wide range. <P>SOLUTION: The auxiliary light projector A mounted on or built in a camera incorporating an automatic focus detector 40, for automatically or manually projecting a focus detecting pattern 20 to an object and allowing the automatic focus detector 40 to detect the focus detecting pattern 20, comprises: a light source section 31; a projection section for projecting a light from the light source 31; and an optical member 33 for deflecting the light, and the optical member 33 that has a plurality of mirrors 32 whose tilt angle is controllable and that respectively controls the tilt angles of a plurality of the mirrors 32 to form the focus detecting pattern 20. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an auxiliary light projection device for automatic focus detection.
[0002]
[Prior art]
Conventionally, in an auxiliary light projection device used for automatic focus detection of camera shooting, when a subject is dark or has no contrast, a slit-shaped striped pattern is projected on the subject, and the pattern is detected by the camera. Perform automatic focus detection. In recent years, the detection area of the automatic focus detection has been expanded. For this reason, in the auxiliary light projection device, for example, by further dividing and projecting a striped pattern used for automatic focus detection that is arranged in advance, a focus detection pattern that can perform automatic focus detection in a wider range is used. (For example, see Patent Document 1).
[0003]
In such an auxiliary light projection device, a method of projecting a focus detection pattern on an object by arranging a film pattern on which a focus detection pattern is formed in front of an LED serving as a light source, or a method of projecting a pattern formed on an LED, There has been used a method of dividing the image into a plurality of parts by using a lens or the like and projecting the image onto a subject, and using the resultant as a focus detection pattern (for example, see Patent Document 2).
[0004]
[Patent Document 1]
JP-A-6-347690 (FIG. 3)
[Patent Document 2]
JP-A-6-313839 (paragraph "0014", FIG. 6)
[0005]
[Problems to be solved by the invention]
However, the auxiliary light projection device having the above-described method of forming a focus detection pattern has the following problems.
[0006]
Since the shape of the former film pattern and the shape of the pattern formed on the latter LED are predetermined, the defocus amount and defocus direction are erroneously detected due to the periodic pattern depending on the distance measurement sensor used. As a result, a problem of so-called false focusing occurs in which the focus is determined at the defocused point.
[0007]
Further, the irradiation magnification of the former film pattern shape and the latter pattern shape formed on the LED is determined in advance by a light projection lens or the like used. Therefore, the irradiation magnification of the irradiation pattern applied to the distance measuring sensor differs depending on the focal length of the photographing lens. For example, when a lens having a focal length of about 105 mm is used, the magnification of the irradiation pattern becomes considerably higher than that of the distance measurement sensor. There has been a problem that the distance cannot be measured.
[0008]
Furthermore, in the former, the film pattern has to be changed to an appropriate shape each time according to the size of the automatic focus detection area.
[0009]
Also, in the latter case, when the focus detection pattern is divided and irradiated, if it is intended to correspond to only a part of the AF area using each divided pattern, the division is performed very complicatedly by an optical member or the like. Needed. Then, it is inevitable that the configuration becomes very complicated, such as determining whether or not each divided pattern is lit. Further, since the light amount ratio of the divided pattern is determined in advance, it has been impossible to freely adjust the light amount only at a necessary portion when necessary.
[0010]
In the latter case, if the number of divisions is blindly increased to cope with a wide range of focus detection, the amount of light at the subject decreases, and it becomes necessary to use a plurality of LEDs, or the power applied to the LEDs is increased. This is problematic in terms of cost, influence on the life of the LED light source, shortening of the life of the battery used, and the like.
[0011]
Also, in the latter case, it is necessary to arrange the pattern formed on the LED perpendicular to the sensor depending on whether the sensor is vertically long or horizontally long, so that various restrictions arise in space and arrangement. I will.
[0012]
The present invention has been made in view of the above problems, and has as its object to provide an auxiliary light projection device that projects focus detection patterns of various shapes having high contrast over a wide range.
[0013]
[Means for Solving the Problems]
In order to achieve the above-mentioned target, according to the present invention, a focus detection pattern is automatically or manually attached to a camera having a built-in automatic focus detection device, and the focus detection pattern is projected onto the subject. In the auxiliary light projection device to be detected by the detection device,
The auxiliary light projection device includes a light source unit, a light projecting unit that projects light from the light source unit, and an optical member that deflects the light, wherein the optical member has a plurality of tilt angles that can be controlled. An auxiliary light projection device having a mirror, wherein the focus detection pattern is formed by controlling the inclination angles of the plurality of mirrors, respectively.
[0014]
In the auxiliary light projection device according to the aspect of the invention, it is preferable that the focus detection pattern is configured by reflected light from the plurality of mirrors.
[0015]
In the auxiliary light projection device according to the aspect of the invention, it is preferable that a magnification of the focus detection pattern can be changed based on a focal length of a photographic lens mounted on a camera.
[0016]
In the auxiliary light projection device according to the aspect of the invention, it is preferable that the auxiliary light projection device can adjust the light amount of the focus detection pattern by controlling the inclination angles of the plurality of mirrors.
[0017]
Further, in the auxiliary light projection device according to the present invention, the focus detection pattern is projected on a position on a subject corresponding to the AF area selected in association with at least one AF area selected by the automatic focus detection device. Preferably, the inclination angles of the plurality of mirrors are controlled.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
[0019]
FIG. 1 shows a schematic configuration diagram in which an auxiliary light projection device according to the present invention is mounted on an autofocus camera, and FIG. 2 shows a schematic configuration diagram of a projection optical system of the auxiliary light projection device according to an embodiment of the present invention. FIG. 3 shows an example of a focus detection pattern according to the embodiment of the present invention. 4A is a schematic front view of the optical member shown in FIG. 3, FIG. 4B is a schematic view of a mirror whose tilt angle can be controlled, and FIG. 5 is a diagram illustrating FIG. 4A in more detail. It is. 6 and 7 show examples of mirror settings when forming a focus detection pattern. FIG. 8 shows an example of a focus detection device, and FIGS. 9 and 10 are schematic explanatory diagrams of automatic focus detection.
[0020]
In FIG. 1, a photographing lens 1 allows light of an object field to enter, and a main mirror 3 divides the incident light into a finder system and a focus detection system (not shown). After passing through the main mirror 3, the light beam 7 to the focus detection system is reflected by the sub-mirror 9, enters the focus detection means 11, and is used for distance measurement for automatic focus adjustment. Contrast is detected. In the automatic focus adjustment, after a focus shift of the subject is detected by the focus detection unit 11, a lens driving device (not shown) is controlled via the control unit 13, and the focus adjustment is performed to perform focusing.
[0021]
On the other hand, the information on the brightness or contrast of the incident light from the control means 13 is sent to the determination means 15 and when it is determined that the brightness or contrast of the subject is low, the auxiliary light projection means 17 displays the information on the subject as shown in FIG. The auxiliary light composed of the focus detection pattern 20 shown in FIG. The projected reflected light of the focus detection pattern 20 is incident on the focus detection unit 11 via the imaging lens 1, the main mirror 3, and the sub-mirror 9, and focus detection is performed. After the in-focus point is detected, the main mirror 3 is flipped up, the shutter 18 is operated, and a subject image is formed on the film or the CCD 19. Thus, an autofocus camera equipped with the auxiliary light projection device A is configured.
[0022]
The focus detection pattern 20 has a magnification set by the control unit 13 based on the focal length of the photographing lens 1 mounted on the camera, and is controlled by the auxiliary light projection device A to a desired magnification. 20 is projected on the subject.
[0023]
In this case, it is preferable to change the size of the focus detection pattern so that the size of the focus detection pattern remains the same on the film surface even when the focal length of the lens changes.
[0024]
In addition, the auxiliary light projector A may be built in the autofocus camera, or may be arranged outside the autofocus camera, for example, integrally with an external flash.
[0025]
When the control unit 13 has the function of the determination unit 15, the determination unit 15 may not be provided.
[0026]
Next, a method of forming the focus detection pattern 20 according to the embodiment of the present invention will be described with reference to FIGS.
[0027]
FIG. 2 is a schematic configuration diagram of a projection optical system of the auxiliary optical system according to the present embodiment. 2, the projection optical system 30 includes a light source unit 31 and a projection lens 34 that projects light from the light source unit 31 onto an optical member 33 formed by a plurality of mirrors 32 whose angles can be controlled. The member 35 is a protection member for protecting the projection optical system.
[0028]
As the light source unit 31, a high-brightness LED, a semiconductor laser light source, or the like is used. The light from the light source unit 31 is converted into substantially parallel light by the projection lens 34, and is incident on the optical member 33 arranged at approximately 45 degrees with respect to the optical axis. A plurality of minute mirrors 32 whose angles can be controlled are arranged on the optical member 33, and the light reflected by the plurality of mirrors 32 is emitted in the direction of the subject indicated by the large arrow 36 in the figure. Then, light from the light source unit 31 is projected as a focus detection pattern 20 onto a subject (not shown).
[0029]
The light source unit 31 may be, for example, a very small surface light source, and the focus detection pattern may be formed by very fine dots.
[0030]
The focus detection pattern 20 shown in FIG. 3 is an example of a focus detection pattern emitted from the auxiliary light projection device A to the subject. The shaded portion indicates the bright portion 21 where the subject is irradiated with light, and the non-shaded portion indicates the portion 22 where the subject is not irradiated with light.
[0031]
As shown in FIG. 4A, the optical member 33 is configured by arranging a plurality of mirrors 32 whose angles can be controlled (for example, 16 rows × 16 columns in the figure) on the same plane. As shown in FIG. 4B, each of the plurality of mirrors 32 changes its tilt angle at a predetermined angle with respect to the X axis and the Y axis by a control system and a control mechanism (not shown). It is a configuration that can be done. When the tilt angle of the mirror 32 is set to a desired angle, the light from the light source unit 31 is reflected by the mirror 32 toward a desired place on the subject, and emitted in the direction of an arrow 36 (see FIG. 2). I do. On the other hand, when the angle of the mirror 32 is set to an angle other than the subject direction 36 with respect to the optical axis, the light from the light source unit 31 does not go to the subject direction 36, and the light from the light source unit 31 is irradiated on the subject. Never.
[0032]
FIG. 5 is a diagram for explaining FIG. 4A described above in further detail. Here, A1 ·· A16, B1 ·· B16, ···, P1 ·· P16 are provided on a total of 256 mirrors arranged on the optical member 33 from row 1 to row 16 and from column A to column P. And numbered respectively.
[0033]
For example, FIG. 6 shows a focus detection pattern 20 having five bright portions (irradiation patterns) 21 in the column direction. Here, the inclination angles of the mirrors in rows 1 to 16 in each of AB, DF, H, JM, and OP columns are set so as to reflect the light from the light source unit 31 and illuminate the subject. I do. On the other hand, the mirrors in rows 1 to 16 in columns C, G, I, and N each have an inclination angle set such that the light from the light source light 31 is not reflected toward the subject. In this way, the focus detection pattern 20 is formed and irradiated onto the subject. Then, the automatic focus detection of the camera is performed using the main focus detection pattern 20.
[0034]
FIG. 7 shows an arrangement of mirrors when another focus detection pattern 20a is formed. The focus detection pattern 20a has a shape obtained by rotating the focus detection pattern 20 shown in FIG. 6 by approximately 90 degrees. In the case of FIG. 7, the tilt angles of the mirrors in columns A to P in rows 1-2, 4-6, 8, 10-13, and 15-16 reflect the light from the light source unit 31 and illuminate the subject. Set as follows. On the other hand, the mirrors in columns A to P in rows 3, 7, 9, and 14 are set such that the inclination angles thereof do not reflect the light from the light source light 31 toward the subject. In this way, the focus detection pattern 20a is formed and is irradiated on the subject. Then, automatic focus detection of the camera is performed using the main focus detection pattern 20a.
[0035]
In the above description, among the mirrors of the mirror 32, the case where the inclination angle of the mirror of the portion 22 is set to an angle that does not reflect the light of the light source unit 31 toward the subject is explained. In order to avoid the light quantity loss, in order to avoid the light quantity loss, the mirror is tilted so that the light from the light source section 31 irradiates the same place as the place where any of the mirror sections of the bright section 21 irradiates the subject. It is preferable to set the angle. For example, in FIG. 6, the reflected light of C1 to C16 is on A1 to A16 or B1 to B16, G1 to G16 and I1 to I16 are on H1 to H16, and N1 to N16 are on O1 to O16 or P1 to P16. Respectively, each area of the bright portion 21 receives irradiation light having three or four rows, so that unevenness in brightness can be reduced.
[0036]
In the optical member 33 of the present application, for example, when it is desired to concentrate the irradiation pattern at one location, the light source light 31 can be set so as to be reflected to a portion where the angles of all the mirrors are to be concentrated.
[0037]
Further, in the present embodiment, the case where 256 mirrors 32 of 16 rows × 16 columns are provided has been described, but actually, a very large number of very finely divided mirrors are used to form a focus detection pattern. 20, 20a are formed.
[0038]
The above-described focus detection patterns 20 and 20a are merely examples, and various shapes of the focus detection patterns can be formed by changing the inclination angle of an arbitrary mirror 32 in m rows and n columns (including m = n). At the same time, it is possible to project the focus detection pattern on an arbitrary position on the subject. In addition, a plurality of focus detection patterns having different shapes can be formed and projected onto different places of the subject.
[0039]
In addition, the case where the tilt angle of the mirror 32 can be changed with respect to the X axis and the Y axis has been described. However, for example, a DMD element (Texas Instruments) or the like can be used as the mirror 32 of the present application. A similar focus detection pattern can also be obtained by alternately arranging mirrors whose inclination angle is variable only in one axis in the row direction or column direction, or by arranging them in a checkered pattern, and controlling the inclination angles of a plurality of mirrors. 20, 20a can be formed.
[0040]
Next, automatic focus detection using the focus detection pattern according to the embodiment of the present invention will be described.
[0041]
FIG. 8A shows an example of the automatic focus detection device 40 used in the focus detection means 11 of FIG. 1, and FIG. 8B shows an automatic focus (AF) area corresponding to FIG. 8A. is there. 9A shows an example of the first automatic focus detection, FIG. 9B shows an example of the second automatic focus detection, and FIG. 9C shows an example of the third automatic focus detection. .
[0042]
In the case of this example, focus detection is performed by the focus detection patterns 20, 20a and 20b and the focus detection device 40 shown in FIG.
[0043]
First, the arrangement of the sensors of the focus detection device 40 will be described. The focus detecting device 40 includes a central distance measuring sensor 41, upper and lower distance measuring sensors 43a1, 43a2, 43b1, and 43b2 disposed in the central vertical direction, and left and right distance measuring sensors similarly disposed in the central horizontal direction. 45a1, 45a2, 45b1 and 45b2, upper left diagonal ranging sensors 46a1 and 47a1, lower left diagonal ranging sensors 46a2 and 47a2, upper right diagonal ranging sensors 46b1 and 47b1 and lower right diagonal ranging sensor It has a total of 12 distance measuring sensors 46b2 and 47b2. The center distance measuring sensor 41 is a cross sensor, the upper and lower distance measuring sensors 43a1 to 43b2 are horizontal sensors, the left and right distance measuring sensors 45a1 to 45b2 are vertical sensors, and the left and right oblique upper and lower distance measuring sensors 46a1 to 47b2 are oblique sensors. You are using As shown in FIG. 8B, AF areas 51 to 57b2 are displayed on the viewfinder of the camera corresponding to the respective sensors.
[0044]
The example of the first automatic focus detection shown in FIG. 9A shows a case where the AF area 53a2 is selected by the photographer. In this case, the photographer selects the AF area 53a2 by the AF area selecting means (not shown). In response to this, a control signal is sent from the control means 13 of FIG. 1 to the auxiliary light projecting means 17, and the optical member 33 is controlled so that, for example, the focus detection pattern 20 is irradiated onto the subject corresponding to the position of the AF area 53a2. After the tilt angles of the plurality of arranged mirrors 32 are adjusted, the focus detection pattern 20 is irradiated onto the subject corresponding to the position of the AF area 53a2. Using the focus detection pattern 20 applied to the AF area 53a2, focus detection is performed by the distance measurement sensor 43a2 arranged in the AF area 53a2, and the photographing lens 1 is driven by a drive device (not shown) so as to be in focus. Is driven to perform automatic focusing.
[0045]
FIG. 9B shows the case of the second automatic focus detection. In the second automatic focus detection, the focus detection is performed by the same control as the first automatic focus detection. However, since the distance measurement sensor in the AF area 55b1 is a vertical sensor, for example, the focus detection pattern is shown in FIG. A focus detection pattern 20a having a shape obtained by rotating the focus detection pattern 20 shown in FIG. At this time, the inclination angle of the plurality of mirrors 32 is controlled by a control device (not shown) so that the automatic detection pattern 20a has a mirror arrangement so as to form the focus detection pattern 20a shown in FIG. The light of the section 31 is reflected and emitted to the AF area 55b1. The focus detection is performed by the sensor 45b1 arranged in the AF area 55b1 using the focus detection pattern 20a applied to the AF area 55b1, and the photographing lens 1 is driven by a driving device (not shown) so as to be in focus. Is driven to perform automatic focusing.
[0046]
FIG. 9C shows the case of the third automatic focus detection. In the third automatic focus detection, the automatic focus detection is performed under the same control as the first or second automatic focus detection. Here, since the distance measurement sensor of the AF area 56b1 is the oblique sensor 46b1, for example, the focus detection pattern 20b has a shape obtained by rotating the focus detection pattern 20 by approximately 45 degrees as shown in FIG. 9C. Use At this time, the inclination angle of the plurality of mirrors 32 is controlled by a control device (not shown) so that the automatic detection pattern 20b has a mirror arrangement as shown in FIG. Irradiate the area 56b1. Then, using the focus detection pattern 20b applied to the AF area 56b1, focus detection is performed by the distance measurement sensor 46b1 arranged in the AF area 56b1, and photographing is performed by a driving device (not shown) so as to be in focus. The lens 1 is driven to perform automatic focusing. However, even when irradiating the focus detection pattern 20b rotated obliquely at approximately 45 degrees as described above, the inclination angle of the mirror 32 of the optical member 33 is set at a predetermined angle with respect to the X axis and the Y axis, respectively. By performing the control, the light source light 31 can be irradiated onto the subject.
[0047]
In the present embodiment, the example in which the photographer selects the AF area by the AF area selecting means has been described. However, the camera automatically selects an appropriate AF area from a plurality of AF areas according to the shooting situation. You may do it.
[0048]
In addition, since these controls are performed at high speed, no matter which of the plurality of AF areas 51 to 57b2 is selected, the focus detection pattern (for example, 20, 20a, 20b) corresponding to the selected AF area is the subject. And focus detection can be performed.
[0049]
Irradiation of the focus detection patterns (for example, 20, 20a, and 20b) on the subject corresponding to the AF areas 51 to 57b2 as described above is performed by tilting the plurality of mirrors 32 provided on the optical member 33 and having controllable angles. Therefore, it is not necessary to prepare individual focus detection patterns in advance. Further, the shape of the focus detection pattern is not limited to the focus detection patterns 20, 20a, and 20b, and can be changed as appropriate according to the shape of the sensor.
[0050]
Further, by controlling the inclination angles of the plurality of mirrors 32 of the optical member 33, it is possible to change the shape of the focus detection pattern to the AF areas 51 to 57b2 at high speed and irradiate the AF areas 51 to 57b2. The automatic focus detection can be performed in any order with respect to the position.
[0051]
FIG. 10 shows another example of automatic focus detection. FIG. 10A shows an example of the fourth automatic focus detection, and FIG. 10B shows an example of the fifth automatic focus detection.
[0052]
The fourth automatic focus detection in FIG. 10A shows a case where a plurality of AF areas 62 are arranged over the entire field of view in the viewfinder. By controlling the inclination angles of the plurality of mirrors 32 of the optical member 33 in the AF area group 63 selected in the plurality of AF areas 62 (including 4 × 3 = 12 AF areas 62 in the example). The focus detection pattern group 64 is irradiated to perform automatic focus detection. In this case, the focus detection pattern group 64 has a size that covers the selected AF area group 63, and the automatic focus detection of the selected AF area group 63 can be performed at one time.
[0053]
Note that the above-described automatic focus detection can also be performed by sequentially irradiating the focus detection patterns 20 to the individual AF areas 62 in the selected AF area group 63.
[0054]
FIG. 10B shows an example of the fifth automatic focus detection, and focus detection is performed on a selected AF area group 65 (in the example, including 20 AF areas 62) similar to the fourth automatic focus detection. The case where the automatic pattern detection is performed by irradiating the use pattern group 66 with controlling the inclination angles of the plurality of mirrors 32 of the optical member 33 is shown. In this case, the focus detection pattern group 66 projects a plurality of types of focus detection patterns 66a to 66h onto the subject by controlling the inclination angles of the plurality of mirrors 32. Thereby, it is possible to perform automatic focus detection in each of the selected AF area groups 65.
[0055]
In the above-described case, it is also possible to control the tilt angles of the plurality of mirrors 32 to sequentially form focus detection patterns 66a to 66h, irradiate the object, and sequentially perform automatic focus detection in the AF area group 65. Also, the focus detection pattern group 66 can be formed by combining the focus detection patterns 20, 20a, and 20b shown in FIGS. 9A, 9B, and 9C.
[0056]
Next, a case where the focal length of the photographing lens changes will be described.
[0057]
FIG. 11 shows a conventional example of automatic focus detection, and FIG. 12 shows automatic focus detection according to the embodiment of the present invention.
[0058]
FIG. 11A shows a conventional wide-angle lens having a focal length of, for example, a photographing lens of 35 mm, and FIG. 11B shows a conventional telephoto lens having a focal length of 105 mm, for example, on a film surface. 3A and 3B schematically show the arrangement of an AF area and a focus detection pattern corresponding thereto.
[0059]
In FIG. 11A, nine AF areas 72 are conventionally irradiated with the focus detection pattern 20c. On the other hand, in FIG. 11B, eleven AF areas 72 are irradiated with the focus detection pattern 20c, which is wider than the area on the film surface. Therefore, in FIG. 11A in the case of the wide-angle lens, the focus detection pattern 20c is irradiated at an appropriate magnification to the distance measurement sensor for each of the nine AF areas 72, but in FIG. 11B of the telephoto lens. In this case, since the magnification of the focus detection pattern 20c is applied to the distance measurement sensors for each of the 11 AF areas at an extremely high magnification, the distance measurement sensor may not accurately perform the automatic focus detection depending on the shape of the focus detection pattern. The distance cannot be measured.
[0060]
On the other hand, in the embodiment of the present application shown in FIG. 12, FIG. 12A shows a case where the focal length of the photographing lens is 35 mm, and FIG. 3 schematically shows the arrangement of AF areas on the film surface and the focus detection pattern for the AF area in the case of the telephoto lens.
[0061]
In the embodiment of the present application, the focus detection pattern for the subject is formed by, for example, combining the focus detection patterns 20 and 20a shown in FIGS. 9A and 9B. According to this, FIG. 12B in the case of the telephoto lens is substantially the same as FIG. It can be seen that 20, 20a are irradiated. This is because in FIG. 12B, the inclination angles of the respective mirrors of the plurality of mirrors 32 are controlled so as to be substantially equivalent to the focus detection patterns 20 and 20a in FIG. 12A.
[0062]
As described above, the auxiliary light projection device of the present application can irradiate various shapes of autofocus patterns to desired AF areas by controlling the inclination angles of the plurality of mirrors 32 of the optical member 33, This enables automatic focus detection.
[0063]
Further, the light quantity can be freely adjusted only at the necessary places when necessary.
[0064]
In addition, it is possible to adjust the shape of the periodic pattern according to the focus detection sensor used.
[0065]
Further, the magnification of the focus detection pattern can be adjusted according to the focal length of the photographing lens.
[0066]
The focus detection pattern of the present invention can be applied not only to a silver halide camera but also to a recording medium such as a digital camera (electronic still camera) and a digital video camera.
[0067]
Further, the shape of the focus detection pattern formed by the plurality of mirrors is not limited to the above-described shape, and can be appropriately changed.
[0068]
Further, it is very effective to improve the distance measurement performance by applying the present invention to a case where the contrast is low even if the subject has a certain level of brightness (in the past, it was impossible because of insufficient light quantity).
[0069]
Furthermore, the present invention is not limited to the above-described embodiment, and can be appropriately modified and changed within the scope of the present invention.
[0070]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an auxiliary light projection device that projects focus detection patterns of various shapes having high contrast over a wide range with a simple configuration.
[Brief description of the drawings]
FIG. 1 shows a schematic configuration diagram in which an auxiliary light projection device according to the present invention is mounted on an autofocus camera.
FIG. 2 shows an example of an automatic focus detection pattern according to the embodiment of the present invention.
FIG. 3 is a schematic configuration diagram of a projection optical system of the auxiliary light projection device according to the embodiment of the present invention.
4A is a schematic front view of the optical member shown in FIG. 3, and FIG. 4B is a schematic view of a mirror whose tilt angle can be controlled.
FIG. 5 is a diagram for explaining FIG.
FIG. 6 shows a mirror setting example when a focus detection pattern according to an embodiment of the present invention is formed.
FIG. 7 shows a mirror setting example when another focus detection pattern according to the embodiment of the present invention is formed.
8A shows an example of an arrangement of a distance measuring sensor of a focus detection device, and FIG. 8B shows an example of an AF area corresponding to FIG.
9A is a schematic explanatory view of a first automatic focus detection example, FIG. 9B is a schematic explanatory view of a second automatic focus detection example, and FIG. 9C is a schematic explanatory view of a third automatic focus detection example; FIG.
10A is a schematic explanatory diagram of a fourth automatic focus detection example, and FIG. 10B is a schematic explanatory diagram of a fifth automatic focus detection example.
11A is a view showing a conventional wide-angle lens having a focal length of 35 mm, for example, a photographing lens, and FIG. 11B is a view showing a conventional telephoto lens having a focal length of 105 mm of a photographing lens. The layout of an AF area and the focus detection pattern corresponding thereto are schematically shown.
12A is a diagram illustrating an embodiment of the present invention, for example, in the case of a wide-angle lens having a focal length of 35 mm, and FIG. 12B is a diagram illustrating an example of a photographing lens according to an embodiment of the present invention. FIG. 4 schematically shows the arrangement of AF areas on a film surface and a focus detection pattern corresponding thereto in the case of a telephoto lens having a focal length of 105 mm.
[Explanation of symbols]
1 Shooting lens
3 Main mirror
7 Focus detection system
9 Submirror
11 Focus detector
13 control means
15 Judgment means
17 Auxiliary light projection means
18 Shutter
19 CCD or film
20, 20a Focus detection pattern
20c Conventional focus detection pattern
30 Projection optical system
31 Light source
32 mirror
33 optical members
34 Projection lens
35 Protective member
36 Injection direction
40 Focus detection device
41 Cross sensor
43 Horizontal sensor
45 vertical sensor
46, 47 Oblique sensor
51-56 AF area
62, 72 AF area
63 Selected AF area group
64 patterns for focus detection
65 AF area group selected
66 Focus detection pattern group

Claims (5)

An auxiliary light projection device that is mounted or built into a camera incorporating an automatic focus detection device, automatically or manually projects a focus detection pattern on the subject, and causes the automatic focus detection device to detect the focus detection pattern.
The auxiliary light projection device,
A light source unit, a light emitting unit that emits light from the light source unit, and an optical member that deflects the light,
The optical member has a plurality of mirrors whose tilt angle can be controlled,
The auxiliary light projection device, wherein the focus detection pattern is formed by controlling the inclination angles of the plurality of mirrors. 2. The auxiliary light projection device according to claim 1, wherein the focus detection pattern is configured by reflected light from the plurality of mirrors. 3. 3. The auxiliary light projection device according to claim 1, wherein a magnification of the focus detection pattern is changeable based on a focal length of a photographic lens mounted on a camera. 4. The said auxiliary light projection apparatus can adjust the light quantity of the said focus detection pattern by controlling the inclination angle of these mirrors, The Claim 1 characterized by the above-mentioned. Auxiliary light projection device. In conjunction with at least one selected AF area of the automatic focus detection device, the tilt angles of the plurality of mirrors are controlled such that the focus detection pattern is projected onto a position on a subject corresponding to the AF area. The auxiliary light projection device according to any one of claims 1 to 4, wherein

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