JPH01271716A - Multipoint range-finding camera - Google Patents

Abstract

PURPOSE:To accomplish the operation of switching range-finding points without increasing operating members by using an operating member for manual focusing as the operating member for switching the range-finding points at the time of automatic focusing(AF). CONSTITUTION:In the case of manual focusing, a gear train 7 is disengaged from a transmission gear 31 by switching an AF-M switching lever 3 for switching the AF operation and the manual focusing operation to an M side. At the same time, the range-finding area changeover switches 34 and 35 of the AF-M switching lever 3 are out of a position corresponding to the projection part 42 of a manual focusing ring 4. By engaging the manual focusing ring 4 with the transmission gear and rotating the manual focusing ring, the focusing lens 8 is driven through the transmission gear without load caused by the cocking of a motor. Thus, the range-finding positions can be switched without increasing the operating members.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera capable of measuring distances at a plurality of positions on a photographic screen, and particularly to an operating member for switching to the distance measuring position.

[Prior Art] Conventionally, a camera equipped with a focus detection device is provided with a distance measurement mark near the center of the photographing screen, and the subject to be photographed is usually placed within the mark when photographing. For this reason, when the subject is outside the center of the screen, distance measurement cannot be performed properly and the subject becomes out of focus, making it difficult to use.

Some cameras are equipped with a focus lock device to allow for focusing on areas other than the center of the screen, but in this case, operations such as moving the camera are required to determine the composition after the focus is locked, and the shutter cannot be adjusted. The drawback was that it was a missed opportunity.

Furthermore, some cameras automatically measure the distance of multiple objects and select the closest object distance information from these multiple object distance information to perform focusing, but the object you want to focus on is not always at the closest distance. In many cases, it may be difficult to use because it may not always be available.

[Problem to be Solved by the Invention 1] As a solution to the above-mentioned problems, for example, it is possible to provide a configuration that can measure distances to a plurality of subjects within a photographic screen, and to set one of the plurality of distance measurement positions within the photographic screen. It is also possible to solve the drawbacks of the conventional example by configuring it so that it can be selected.

However, if things continue as they are, it will be necessary to add a new distance measurement position switching device, and cameras are often already equipped with many operating elements such as exposure mode, metering mode, feed mode, ISO, etc. The disadvantage is that it becomes even more complicated. It is also conceivable that the distance measuring position switching device be operated with the right hand, but in this case the finger would be removed from the release button and the photo opportunity would be lost.

Therefore, in addition to making it possible to measure distances at multiple points as described above,
Further, there is a need for a method for selecting a desired distance measurement position intended by a photographer using a simple structure and an easy-to-operate configuration.

[Means for Solving the Problems] The characteristics of the multi-point distance measuring camera according to the present invention that achieves the above object are representatively described as being able to measure object distances at multiple points within the camera's viewfinder. A distance measurement means, a switching means for selecting one of a plurality of distance measurement information that can be obtained by the distance measurement means, and an autofocus device that performs so-called focusing (focus detection) based on the selected distance measurement information. In a camera equipped with an operating member such as a manual focus ring, which is linked to the photographic optical system and manually operated to perform manual focus, the above-mentioned linkage between this operating member and the photographic optical system is used during autofocus. In this case, an operating member such as the manual focus ring is used as the operating member of the switching means for selecting the distance measurement information.

[Function] According to the present invention, the manual focus operation member that is not used during autofocus is used to switch the ranging position required during autofocus, so there is no need to increase the number of operation members compared to the past. It becomes possible to switch distance measurement positions, allowing for effective use of existing components and devices.

[Example] Example 1 An example of a focus detection optical system having a plurality of focus detection areas according to the present invention will be described based on FIG. 4.

In Fig. 4, LO is a photographing lens, and La and Lb
indicates the area through which the focus detection light flux passes on the pupil plane of the photographic lens LO. 21 is a focus detection area mask placed immediately after the planned focal plane, and openings 21a, 21b, and 21c formed in this focus detection area mask 21
The three focus detection areas on the shooting screen are 11°12.13
(See Figure 5).

Openings 21a and 21b on the focus detection area mask 21
And immediately after 21c, a condenser lens 22a,
22b and 22c are arranged. These condenser lenses 22a.

22b and 22c form images of the aperture masks 23a to 23f within the exit pupil of the photographing lens LO. That is, the aperture masks 23a and 23b form images on areas La and Lb within the exit pupil of the photographic lens LO, respectively, by the condenser lens 22a, and the aperture masks 23c and 23d
The condenser lens 22b forms images on areas La and Lb within the exit pupil of the photographic lens LO, respectively. Furthermore, the aperture masks 23e and 23f form images on areas La and Lb within the exit pupil of the photographing lens LO, respectively, from the condenser lens 22c. In this way, the diaphragm masks 23a to 23f define focus detection light flux areas La,' within the exit plane of the photographing lens LO.
This determines Lb.

Immediately after the aperture masks 23a to 23f, an imaging lens 24
a to 24f are arranged respectively.

These imaging lenses 24a to 24f are the photographing lens LO.
This is for secondarily forming an image formed near the focal plane F on the line sensor 26. Imaging lens 24a~
The cylindrical lens 25 disposed immediately after the lens 24f has refractive power only in a direction perpendicular to the direction in which the aperture masks 23a to 23f are arranged, and forms a reduced image on the licensor 26 in that direction. This cylindrical lens 25
In this case, the line sensor 26 is in the horizontal direction (aperture masks 23a to 2
3f), the focus detection area is enlarged in the vertical direction by reducing the image in the vertical direction more than in the horizontal direction, but this is not essential. 2
6a to 26c are image sensors composed of one-dimensional sensors such as CCDs, and the sensor 26a is located at a position to receive images formed by imaging lenses 24a and 24b, and the sensor 26b is located at a position where images formed by imaging lenses 24c and 24d are formed. The sensor 26c is placed at a position where it receives the image formed by the imaging lenses 24e and 24f, and the sensor 26c is placed at a position where it receives the image formed by the imaging lenses 24e and 24f. Therefore, the sensors 26a, 26b, 2
6c can perform distance measurement separately in three different areas (focus detection areas 11, 12, and 13) on the photographic screen.

FIG. 5 is a diagram showing an example of the display in the finder.
In FIG. 5, numeral 10 indicates the entire visual field image, and small areas 11, 12, and 13 indicated by dotted lines (or solid lines) indicate distance measurement areas. In this embodiment, three distance measurement areas are shown, but this is not particularly limited.

The above area display is composed of a display element such as a guest-host liquid crystal display, and is colored by energizing the display element of the distance measurement area selected by the distance measurement area switching operation described later. The distance measurement area can be confirmed. In FIG. 5, the distance measurement area 11 indicated by a solid line is selected (colored).

FIG. 2 shows a perspective view of the external appearance of the camera of this embodiment. In this figure, 1 is the camera body, 2 is a photographing lens,
3 is an AF-M switching lever for switching between autofocus (hereinafter referred to as AF) operation and manual focus operation; 4 is a manual focus ring used for focus operation during manual focus;
Reference numeral 5 designates a release switch consisting of a known two-stage switch that performs photometry/distance measurement in the first stroke and releases in the second stroke.

FIG. 1 is a diagram illustrating details of the AF-M switching mechanism of this embodiment. 3 is the AF-M switching lever shown in Fig. 2, 4
is the manual focus ring similarly shown in FIG. Reference numeral 6 denotes a motor that drives the focus lens 8 by a control signal from a control circuit (not shown) of the camera body during AF;
Transmission gear 31.3 rotatably fixed to the switching lever 3
The driving force of the motor 6 is applied to the focus lens 8 through the
The signal is transmitted to the gear section 81 of. The feature of this example is that the tip of the arm 3a integrally extended from the AF-M switching lever 3 faces the inner circumferential surface of the manual focus ring 4 in the AF state shown in FIG. A pair of switches 34 and 35 for switching the distance measurement area are provided on both sides in the circumferential direction, and on the inner surface of the manual focus ring 4, there are switches 34 and 35 for switching the distance measurement area. A protrusion 42 is provided for operating the switch 34, 35 by engagement with the switch 34, 35. That is, these switches 3 in this example
4.35 and the protrusion 42 in the state shown in FIG.
A first state in which both switches 34 and 35 are turned off;
A second state when the manual focus ring 42 is rotated in the D1 direction in the figure to engage the protrusion 42 with the switch 34 and turned on, and a second state in which the manual focus ring 42 is rotated in the D2 direction in the figure. A total of three states can be selected, including a third state when the protrusion 42 is engaged with the switch 35 and turned on, thereby indicating the ranging area shown in FIG. This means that any of the small areas 11, 12, and 13 can be selectively colored.

In addition, in the configuration of this example, the AF-M switching lever 3 is
By moving in the direction D3 in the figure, the gear train 7 for AF drive and the transmission gear 31 are disengaged, allowing manual focus operation, and the switches 34 and 35 are switched to AF-M as described above. Since it is provided at the tip of the arm 3a integrally extending from the lever 3, by moving the AF-M switching lever 3 in the direction D3 in the figure, these switches 34, 35 and the manual focus ring 4 can be switched. The opposing relationship between the two has also been removed.

Therefore, even if the manual focus ring 4 is rotated, the switches 34 and 35 will not be turned on or off.

Also, due to this switching, the transmission gear 32, which is rotatably fixed to the AF-M switching lever 3, engages with the gear portion 41 of the manual focus ring 4, so that the rotation of the manual focus ring causes the transmission gear 32, 33 to be rotated. It becomes possible to drive the focus lens 8 through the lens.

FIG. 3 is a circuit block diagram illustrating the relationship between on/off of the switches 34 and 35 described above and the coloring of the marks of the small areas 11.about.12.13 indicating the distance measurement areas. In this figure, 101 is a distance measuring element, which is a CCD (fourth
106 is a CCD drive circuit for driving and controlling this CCD, and 102 is a ranging area (corresponding to 34.35 in FIG. 1) selected by the ranging area changeover switch 107 (corresponding to 34.35 in FIG. For example, a selection circuit for selecting a signal from the COD 101 corresponding to reference numeral 11) in FIG. , 10
4 is a motor drive circuit for driving the motor 105 (corresponding to number 6 in FIG. 1), and 108 is a display element 109 (corresponding to number 6 in FIG. This is a display selection control circuit for displaying (corresponding to 11°, 12.13). 1
Reference numeral 10 denotes a motor control circuit for controlling the drive/stop rotation amount of the motor based on the lens movement amount signal output based on the distance measurement information calculated by the calculation circuit 103 in response to the signal from the distance measurement area changeover switch 107. It shows.

Next, a series of operations performed by the configuration of this embodiment described so far will be described.

First, power is supplied to each circuit by turning on a power source (not shown). Look through the viewfinder to decide on the composition of the subject to photograph. At this time, for example, let's assume that the manual focus ring 4 is in the state shown in Figure 1, and the distance measurement area is 12, and that the focus is set by pressing the release switch to the first stroke, but the focus is on the background, and the photographer Assume that the intended main subject is out of focus and the composition is unclear. Therefore, in this case, the distance measurement area changeover switch 34 is turned on by rotating the manual focus ring 4 to the left. As a result, the display selection control circuit 108 erases the display of the distance measurement area 12 and displays the distance measurement area 11 in parentheses. At the same time, the selection circuit 102 selects the CCD corresponding to the distance measurement area 11 by the ON signal of the distance measurement area changeover switch 34, and selects the CCD corresponding to the distance measurement area 11, and
3 calculates and outputs a predetermined lens movement amount signal to the motor control circuit 110. The motor control circuit 110 that has received the signal from the arithmetic circuit 103 outputs the lens movement amount and a drive start signal to the motor drive circuit 104 to drive the motor. As mentioned above, the driving force of this motor is transmitted to the focus lens 8 through the gear train 7 and the transmission gears 31 and 33.
transmitted to. This allows you to see an in-focus image of the main subject in the viewfinder, allowing you to instantly decide on the composition.

If you want to focus manually, switch the AF-M switching lever 3 to the M side, as described above, the gear train 7 and the transmission gear 31 will disengage, and the AF-M switch lever 3 will disengage from the transmission gear 31 as described above.
The distance measurement area changeover switches 34 and 35 of the M changeover lever 3 are removed from the positions corresponding to the projections 42 of the manual focus ring 4. By engaging the manual focus ring 4 and the transmission gear 32 and rotating the manual focus ring, the focus lens 8 can be driven via the transmission gears 32 and 33 without any load due to motor jerking.

Embodiment 2 FIG. 6 is a diagram showing another embodiment. The characteristics of this example are:
A manual focus ring 4' is provided so as to be slidable in the direction of the arrow in the figure.
Switch 34. is activated by sliding the lens in the optical axis direction.
35 and is engaged with and separated from it. Therefore, switches 34 and 35 are fixed to the lens barrel,
Other configurations are the same as in the embodiment. The figure shows the AF state, and the driving force of the motor 6 is transmitted to the focus lens 8 via the gear train 7 and transmission gears 31 and 33, and when changing the distance measurement position, the manual focus ring is moved in either direction in the circumferential direction. Rotate to select distance measurement position switch 34.
Turn 35 on and off. This switching is the same as in the first embodiment.

In the case of manual focus, by sliding the manual focus ring forward (to the left in the figure), the transmission gear 32 and the gear portion of the manual focus ring are meshed. At this time, the ring 4' is simultaneously displaced from the position corresponding to the distance measurement position changeover switch 34, 35. Therefore, by rotating the manual focus ring 4', the focus lens 8 can be driven and focused via the transmission gears 32, 33. In this example, the transmission gear 31 and the gear train 7 remain engaged in the case of the above-mentioned switching, but it is natural that the gear train 7 is disengaged in accordance with the above-mentioned sliding operation of the manual focus ring. This is possible, and in this way, the AF-M switching lever, which is an operating member, can be omitted.

[Effects of the Invention] As explained above, in the present invention, by using the operation member for performing manual focus as the operation member for switching the focus point during AF, measurement can be performed without increasing the number of operation members compared to the past. This has the effect of making it possible to add a new function of focus switching operation.

Furthermore, since the operation is simple, there is an effect that the applicability of the camera capable of measuring distances at multiple positions to actual use can be increased.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional perspective view of a camera showing an outline of the configuration of Embodiment 1 of a mechanism for switching the distance measurement position according to the present invention, FIG. 2 is an external perspective view of the camera, and FIG. 3 is a distance measurement FIG. 4 is a block diagram of a circuit that controls position switching, FIG. 4 is a diagram showing an example of a focus detection optical system, FIG. 5 is a diagram for explaining the display in the viewfinder of Embodiment 1, and FIG. FIG. 7 is a partially cross-sectional perspective view of a camera showing an outline of the configuration of a mechanism for switching distance measurement positions according to a second embodiment. 1...Camera body 2...Photographing lens 3...
AF-M switching lever 4.4'...Manual focus ring 5...Release switch 6...Motor 7...Gear train 8...Focus lens 10...Entire visual field image 11.12.13 ...Small area 21...Focus detection area mask 21a-21c...Focus detection area 22a-22c...Condenser lens 23a-23f
...Aperture mask 24a to 24f...Imaging lens 26...Licensor 26a to 26c...Image sensor 31.32.33...Transmission gear 34.35...Switch 41...Gear section 42... Protrusion 81...
Gear part diagram 5

Claims (1)

[Claims] 1. A distance measuring means capable of measuring the distance of each subject corresponding to a plurality of points in a photographic screen, a switching means for selecting one of a plurality of distance measuring information obtained by this distance measuring means, and a selected one. an automatic focus detection device that drives the photographic optical system for focus detection based on distance measurement information; and an automatic focus detection device that is linked to the photographic optical system to enable manual focus detection, and the link is released during automatic focus detection. a multi-point distance measuring camera, characterized in that the operating means is configured to select the switching means at the time of automatic focus detection in which the linkage is canceled. .