JPS59195601A - Camera provided with range finding mechanism - Google Patents

Abstract

PURPOSE:To perform photographing automatically in a wide range with a simple constitution by forming a control circuit switching a proximity photographing mode to a normal photographing mode through a switching means when a range finding means generates a long range signal in the proximity photographing mode. CONSTITUTION:When a rear group 8 of a photographing lens 6 focuses a subject in a normal photographing range under the state of the proximity photographing exceeding an optical axis and a release button is depressed up to the 1st step, range finding is performed and an automatic focus detector outputs a long range signal to supply current to an electromagnetic solenoid 18. Consequently, a clamping member 16 moves in the counterclockwise direction, an auxiliary lens part 3b of a photodetecting lens 2 is covered with a mask 5, a main lens part 3a is made effective and the opening limitation of a projection lens 2 is removed, so that almost all ranges of the projection lens 2 is made effective. Simultaneously, the post group 8 of the photographing lens 6 is moved by a spring 14 together with the movement of the mask 5 and acts as a lens forming an image of the subject in the normal photographing range on a film surface together with the front- group 7. The series of operations makes it possible to complete switching from the proximity photographing mode to the normal photographing mode.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera equipped with a distance measurement mechanism that can be switched between a normal photography mode and a close-up photography mode, and the distance measurement function works in either case.

Conventionally, various cameras are known that are capable of normal photography and close-up photography, but for example, if you set the camera to close-up photography mode and perform close-up photography, and then perform normal photography, the camera is often set to normal photography mode. Sometimes I forget this and end up taking pictures that are out of focus.

An object of the present invention is to improve the above-mentioned problems, to enable switching between normal shooting mode and close-up shooting mode using a relatively simple mechanism, and to automatically switch from close-up shooting mode when photographing a subject at a normal distance. The purpose of the camera is to provide a camera equipped with a distance measuring mechanism that switches to normal shooting mode. The camera is characterized by comprising a distance measuring means and a control circuit that switches to the normal photographing mode via the switching means when the distance measuring means emits a long distance signal in the close-up photographing mode.

The present invention will be explained in detail below based on illustrated embodiments.

Fig. 1 shows an overview of the distance measuring optical system, in which a light beam emitted from a light emitting element 1 such as a light emitting diode is projected onto a subject by a light projecting lens 2, and the reflected light is sent to a light receiving sensor via a light receiving lens 3. The image is formed on 4. However, unlike conventional distance measuring optical systems, the light receiving lens 3 has a special shape in which a main lens section 3a used for normal photography and an auxiliary lens section 3b used for close-up photography are integrally formed. The switching operation between normal photography and close-up photography is linked to the mask 5, and by moving the mask 5, the distance measuring optical system is switched.

FIG. 2 shows a photographic lens 6, and a shutter 9 which also serves as an aperture is interposed between a front group 7 and a rear group 8 of the photographic lens 6. The rear group 8 as a whole acts as a concave lens or a flat glass, and the imaging position is farther from the photographic lens 6 than when the rear group 8 is not provided.

FIG. 3 shows a specific embodiment, in which the above-mentioned mask 5 is attached so as to be able to slide guided by a pin 10 fixed to the camera body, and is also attached in the direction of arrow A by a tension spring 11. is energized by The rear group 8 of the photographic lens 6 is pivoted so as to be rotatable by a limited angle around a fixed pivot shaft 12, and is biased counterclockwise by a spring 14 whose one end is latched to the fixed shaft 13. . rear group 8
A pin 7a is implanted in a part of the lens barrel, and this pin 15 is brought into contact with the mask 5 so as to follow it. In this way, the mask 5 is normally pulled in the direction A by the elastic force of the tension spring 11, but when the mask 5 moves in the direction of the arrow B, the mask 5 is stopped by the tensioning member 16. It is now possible to do so. This tensioning member 16 is rotatably supported in the horizontal direction via a shaft (not shown), and the spring 1
7 in the time direction when viewed from above, and is rotated counterclockwise against the spring 17 by the operation of an electromagnetic solenoid 18 to release the mask 5 from the lock. Further, the mask 5 is pulled in the direction A by the tension spring 20 of the operating knob 19. A close-up photography switch 21 is arranged on the side of the mask 5.
When the switch moves in the B direction, it turns on, and when it moves in the A direction, it turns off.

FIG. 3 shows close-up photography with the rear group 8 of the photographic lens 6 off the optical axis, and the -2 lens 5 is held in the direction B by the tensioning member 16. There is. At this time, the mask 5 allows the light-receiving lens 3 to
is covered, the auxiliary lens yr++3b is enabled,
Further, the aperture of the light projecting lens 2 is limited by a mask 5. In this state, when the user presses the release button to the first step while aiming at a subject within the distance range for normal photography, such as 1 m or more, distance measurement is performed and the automatic focus detection device outputs a long distance signal. When this state is maintained for a predetermined time of 100 m5, for example, the electromagnetic solenoid 18 is energized, the tension member 16 moves counterclockwise, and the light receiving lens 3
The auxiliary lens part 3b is covered with the mask 5, and the main lens part 3
a becomes valid. Further, the aperture restriction of the light projecting lens 2 is removed, and almost the entire area of the light projecting lens 2 becomes effective. At the same time, the rear group 8 of the photographic lens 6 is moved by the spring 14 to follow the movement of the mask 5, and works together with the front group 7 to function as a lens for forming an image of a subject at a normal photographing distance on the film plane.

This series of operations completes the switching from the close-up photography mode to the normal photography mode.

FIG. 4 shows a circuit diagram for automatic switching from the close-up mode to the normal mode. In FIG. 4, the outputs of the elements 4a, 4b, . . . of the light receiving sensor 4 are outputted from the processing circuit 3° to the arithmetic circuit 31 and the NOR circuit 32 as outputs for each fist of the elements 4a, 4b, . Ru.

The output of the NOR circuit 32 is sent to the NAND circuit 33,
The NAND circuit 33 is further supplied with an input signal from a power supply 34, a power switch 35 linked to a lease button, etc. via a delay circuit 36, and an input signal from the power switch 35 via a close-up switch 21 disposed on the side of the mask 5. input signal is connected. Note that the output of the delay circuit 36 changes from O to 1 when, for example, rooms have passed after the switch 21 is turned on. And NAN
The output of the D circuit 33 energizes the coil 38 of the electromagnetic solenoid 18 via the PNP' transistor 37.

In the circuit operation when switching from close-up shooting to normal shooting, when you press the release button of the camera while facing the subject in the normal shooting range while the camera is in the close-up shooting mode, the power switch 35 is turned on and the power switch 35 is turned on. The light emitting element 1 is turned on via a control circuit that does not operate. However, since the subject does not exist within the interlocking distance range during close-up photography, any of the elements 4a, 4b of the light receiving sensor 4,
..., the signal light reflected by the object does not enter. Therefore, the output of the processing circuit 30, which outputs 1 when an input signal is present and 0 when there is no input signal, is 0, and the output of the NOR circuit 24 is 1. Furthermore, since the close-up switch 21 is turned on by being pressed by the mask 5, when the output of the delay circuit 36 becomes 1 after a predetermined period of time, the output of the NAND circuit 33 turns on and the transistor 37 turns on. The coil 38 of the electromagnetic solenoid 18 is energized. As a result, the tension member 16 rotates, the mask 5 moves in the A direction, and the close-up switch 21 is turned off, so the output of the NAND circuit 33 is turned off and the coil 3
Power to 8 is cut off. These operations enable normal photography, and a lens movement signal for automatic focusing is output from the arithmetic circuit 31, and while moving the front group 7 of the photographic lens 6, it sends an optical signal to the light receiving element 4. Since it is well known that the movement of the front group 7 is stopped by detecting the peak of , a description of these mechanisms will be omitted here.

In the above-mentioned embodiment, when a predetermined time has elapsed after the power switch 35 is turned on, it is detected that the close-up mode is out of the interlocking range, but this prevents malfunctions and simple erroneous operations by the photographer. It is for. Furthermore, as a modification of this embodiment, instead of the delay circuit 36, a signal when the release button is pressed deeply, that is, a shirt release signal, is used to detect an area outside the interlocking range of the close-up shooting mode. It is also possible to switch from close-up photography mode to normal photography mode while locking the shirt release.

FIG. 5 shows a circuit for this purpose, and the same reference numerals as in FIG. 4 indicate the same circuits. The input to the NAND circuit 33 is
A release switch 40 is used instead of the delay circuit 36, and when the release switch 40 is turned on in the close-up shooting mode without +=Q of the light receiving sensor 4, the NAND circuit 3
3 becomes 0, and the coil 38 is energized as described above. At this time, the output of the NAND circuit 33 is also connected to a delay circuit 41, and the output of this delay circuit 41 and the output of the release switch 40 are connected to an AND circuit 42.
The camera is configured so that the release operation of the camera is started when the output is 1.

Therefore, when the output of the NAND circuit 33 is O, the output of the delay circuit is also O, and the output of the AND circuit 42 is also O, so that no camera release operation occurs. When switching from the close-up photography mode to the normal photography mode is started by energizing the coil 38, the close-up photography switch 21 is turned off, the output of the NAND circuit 33 becomes 1, and the energization to the coil 38 is cut off. . Then, since the input of the delay circuit 41 also becomes 1, the switching from the close-up shooting mode to the normal shooting mode is completed, and the output of the delay circuit 41 becomes 1 after a sufficient time has elapsed for the distance measurement operation to be performed. The output of the AND circuit 42 becomes 1 and the release operation of the camera is started.

As explained above, according to the camera equipped with the distance measuring mechanism according to the present invention, it is possible to switch from the close-up shooting mode to the normal shooting state with a relatively simple configuration, and the advantage is that shooting over a wide range can be automatically carried out. There is.

[Brief explanation of the drawing]

The drawings show an embodiment of a camera equipped with a distance measuring mechanism according to the present invention, and FIG. 1 is an explanatory diagram of the distance measuring optical system, FIG. 2 is a sectional view of the photographic lens, and FIG. 3 is a main part. Perspective view of 4th
The figure is a block circuit configuration diagram for mode switching, and FIG. 5 is a block circuit configuration diagram of a modification thereof. 1 is a light emitting element, 2 is a light emitting lens, 3 is a light receiving lens,
3a is a main lens part, 3b is an auxiliary lens part, 4 is a light receiving sensor, 5 is a mask, 6 is a photographing lens, 7 is a front group, 8 is a rear group, 16 is a tensioning member, 18 is an electromagnetic solenoid, 21 is a proximity member Photographing switch, 30 is a processing circuit, 31 is an arithmetic circuit, 38
is a coil. Patent Applicant Canon Co., Ltd. Figure 1 Figure 2 EIiii Figure 4 1, - Figure 5

Claims (1)

[Scope of Claims] 1. A switching means for switching between a normal shooting mode and a close-up shooting mode, a distance measuring means for detecting a subject distance in both shooting modes, and a distance measuring means for detecting a long-distance signal in the close-up shooting mode. 1. A camera equipped with a distance measuring mechanism, characterized in that the camera is equipped with a control circuit that switches to a normal shooting mode via the switching means when an image is emitted. 2. The distance measuring mechanism according to claim 1, wherein switching from the close-up photography mode to the normal photography mode is performed by inserting a part of the photography optical system into the photography optical path. camera. 3. The photographing optical system comprises a front group located on the subject side and a rear group located on the film side, and the rear group is a part of the photographing optical system inserted into the photographing optical path. A camera equipped with the distance measuring mechanism according to item 2.