JPH0797195B2 - Camera body and interchangeable lens - Google Patents

Description

The present invention relates to a camera body and an interchangeable lens.

[Conventional technology]

The non-lens interchangeable type 35 mm camera is generally called a compact camera, and a so-called lens shutter device that uses both a shutter and an aperture is mounted as an exposure control device in this type of camera. Further, it has become common to automatically wind and rewind the film by using the power source of the camera. Furthermore, even in so-called single-lens reflex cameras with interchangeable lenses, various mechanisms such as an automatic exposure device, an automatic film winding device, an automatic focusing device, and an automatic film rewinding device are stored in one camera, The operation of the above mechanism is automatically performed by one power source. Further, in recent years, there has been filed an application for using a step motor for driving the diaphragm, which has a simple structure and can be manufactured at a low cost. However, in the case of such a conventional device, since the rotor of the step motor is formed of a permanent magnet, it is often the case that the diaphragm should be opened where it should be open due to shock or vibration.

Therefore, for example, as disclosed in Japanese Patent Laid-Open No. 58-111022, when the aperture is not open at the beginning of photometry before the release operation, the stepping motor rotates to the open side to return the aperture to the open position. Was proposed. In addition, Japanese Utility Model Laid-Open No. 56-32823 has proposed a technique of driving the aperture in the opening direction every time the release button is operated. However, neither considers a camera system having an interchangeable lens. That is, no consideration is given to the control of the aperture in the camera system in which the camera body and the interchangeable lens are detachable, and the interchangeable lens detached from the camera body is provided with the aperture motor and the aperture.

〔Purpose〕

The present invention provides suitable aperture control in a camera system in which a camera body and an interchangeable lens are detachable,
An object of the present invention is to provide a camera main body and an interchangeable lens which can open an aperture at an early point before the shutter release operation and can immediately perform photographing.

In order to achieve the above object, the present invention provides a diaphragm motor,
An interchangeable lens having an aperture that operates using the aperture motor as a drive source, an aperture detection unit that detects an open state of the aperture, and a lens-side control circuit that drives the aperture motor in response to communication from the camera-side control circuit. When the interchangeable lens is attached to the camera body and the camera-side control circuit and the lens-side control circuit can communicate with each other, When the open state is not detected, the camera side control circuit is characterized by the camera body that performs communication for driving the aperture to open to the lens side control circuit.

Further, the present invention is an interchangeable lens that can be mounted on a camera body having a camera-side control circuit, the interchangeable lens comprising an aperture motor, an aperture that operates using the aperture motor as a drive source, and an open state of the aperture. And a lens side control circuit for driving the aperture motor in response to communication from the camera side control circuit, the interchangeable lens being mounted on the camera body, and the lens side control circuit. When the diaphragm detection means does not detect the open state of the diaphragm when the camera side control circuit becomes communicable, the lens side control circuit communicates from the camera side control circuit. It is characterized by an interchangeable lens that receives the light and drives the diaphragm motor to open.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a configuration diagram schematically showing the configuration of the essential parts of a camera, an electric drive device for a photographing lens, and a circuit according to the present invention. Reference numeral 1 is a camera body, 2 is a taking lens as an interchangeable lens that is detachably attached to the camera body 1, and is connected to a camera mount 1a and a lens mount 2a, respectively. 3 is a mirror, 4 is a pentaprism, 5 is an eyepiece lens, and 6 is a light receiving element for photometry. 7 is a photometric calculation circuit,
8 film sensitivity information input circuit, 9 shutter control circuit, 1
It is connected to 0 microcomputers. Reference numeral 34 is a focal plane shutter, 3a is a mirror rotation shaft, and 3b is an operation pin, which faces the mirror drive cam 11. Reference numeral 12 is a mirror drive motor, which is connected to the motor drive circuit of 13. A film winding and rewinding motor 14 is connected to the motor drive circuit 15. 16 is a distance measuring sensor,
It is connected to 17 ranging circuits. 18 is the battery that controls the operation of the camera system, 19 is the main power switch, and 20 is
DC / DC converter, battery 18 to microcomputer 1
Connected to 0.

Reference numeral 21 is a metering / distance measuring switch, and 22 is a shutter release switch. Reference numeral 23a is a group of contact pins on the camera body 1 side, which are arranged near the mount 1a, and 23b is a taking lens 2
The contact pin group on the side is arranged so as to face the contact pin group 23a on the camera body 1 side when the lens mount 2a of the photographing lens 2 and the camera mount 1a of the camera body 1 are completely mounted.

G ₁ and G ₂ are photographing optical lenses, and 24 is an electrically driven diaphragm having a stepping motor (not shown) for driving a diaphragm, which forms 25 focusing optical systems. 26 is a lens drive motor used for focus adjustment, connected to the lens drive circuit of 27,
The output shaft of the lens driving motor 26 is linked with 28 pulse plates. Reference numeral 29 is a photoreflector which is arranged so as to face the pulse plate 28 and is connected to the waveform shaping circuit 30. 31
Is a diaphragm drive circuit, which is connected to the in-lens microcomputer shown by 32. 33 is an aperture open detection switch
It is connected to the microcomputer 32. Reference numeral 40 denotes a mount mounting detection switch. The switch 40 is provided on the camera body 1 side, and when the lens mount 2a of the taking lens 2 is attached to the camera mount 1a, a contact provided on the lens mount 2a of the taking lens 2 when the mounting is completed. It is provided so as to be closed by the pressing member 2b. Reference numeral 35 is a warning display portion for displaying a malfunction of the electrically driven diaphragm 24.

Regarding the camera system of the present invention having the above configuration,
A description will be given according to the flow chart of FIG.

In FIG. 2, in step # 1, first, the main power switch 19 of the camera body 1 is closed, the DC / DC converter 20 is turned on, and a constant voltage is applied from the DC / DC converter 20 to the micro computer 10 on the camera 1 side, the photographing lens. A constant voltage is supplied to the second microcomputer 32,
Bring 10 and 32 to standby. Then step #
In FIG. 2, the taking lens 2 is attached to the camera body 1 by coupling the lens mount 2a to the camera mount 1a. In this mounting completed state, the mount adhesion detection switch 40 is closed by the contact pressing member 2b implanted in the lens mount 2a. In response to the closing of the switch 40, the DC / DC converter 20 is started at step # 3, and step # 4
Then, the operation of the microcomputer 10 is started. At step # 5, the aperture open detection switch 33 detects whether or not the aperture of the electrically driven aperture 24 of the taking lens 2 is open. When the aperture open detection switch 33 is closed, the aperture may be impacted. Since the aperture has been narrowed down, in step # 6, the microcomputer 10 of the camera body 1 communicates with the microcomputer 32 of the taking lens 2 via the contacts 23a and 23b to instruct the microcomputer 32 to control in the aperture opening direction.

In steps # 7 and # 8, the microcomputer 32 of the taking lens 2 instructs the diaphragm drive circuit 31 to open the electrically driven diaphragm 24 in the opening direction by a stepping motor (not shown). Mount mounting detection switch
The stepping motor continues to be energized until a predetermined time (for example, 1 second) elapses after 40 is closed, and the stop open detection switch 33 closes even after the predetermined time elapses. If it is, that is, if the diaphragm still does not open, the warning display portion 35 formed by a buzzer or a lamp is driven by a command from the microcomputer 10 at step # 9 to notify the user of the accident.

When the aperture open detection switch 33 is opened within the predetermined time and it is detected that the taking lens 2 is opened, the sequence proceeds to step # 10 to determine the state of the photometric switch 21, and when closed, the step # The light is measured at 11 and the step # 12 shifts to the shutter release sequence. The shutter release sequence of step # 12 is the same as the normal camera operation (that is, the operation including the opening and closing of the shutter) and is omitted. When the photometry switch 21 is open at step # 10, the DC / DC converter 2 at step # 13 after a predetermined time
0 falls, step # 14, micro computer 10
And deactivate 32.

In the above description, the elapsed time after the mounting detection switch 40 is turned on (also referred to as ON) is measured at step # 8, and a warning is issued at step # 9 after a certain time has passed. Is omitted, and step # 6 → step # 7 → step # is always executed until the aperture open detection switch 33 is switched.
The flow of 5 → step # 6 → step # 7 → step # 5 (see the dotted line portion in the second illustration) may be performed.

〔The invention's effect〕

As described above, according to the present invention, in the camera system having the interchangeable lens provided with the diaphragm and the diaphragm motor, the diaphragm in the interchangeable lens is opened when the camera body and the interchangeable lens can communicate with each other. If not, the camera body communicates with the interchangeable lens to open the aperture, so
Since the aperture can be opened at an early point before the shutter release operation, it is possible to provide a camera body and an interchangeable lens that enable immediate shooting, and can accurately perform photometry and distance measurement before shooting. it can.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention. FIG. 1 is a configuration diagram schematically showing the configuration of an electric drive device for a camera and a lens and a main portion of a circuit, and FIG. 2 is a flow chart. It is a chart. 1 …… Camera body 2 …… Interchangeable lens body 7 …… Metering calculation circuit 18 …… Battery 24 …… Electric drive diaphragm 31 …… Aperture drive circuit 33 …… Aperture open detection switch 34 …… Mount mount detection switch 35 …… Warning display

Claims (2)

[Claims] 1. A diaphragm motor, a diaphragm which operates by using the diaphragm motor as a drive source, a diaphragm detecting means for detecting an open state of the diaphragm, and a camera side control circuit which receives communication from the camera side control circuit. A camera body capable of mounting an interchangeable lens having a lens side control circuit to be driven, wherein the interchangeable lens is mounted on the camera body and the camera side control circuit and the lens side control circuit can communicate with each other. In addition, when the aperture detection means does not detect the opening of the aperture, the camera side control circuit performs communication for driving the lens side control circuit to open the aperture. The main body of the camera. 2. An interchangeable lens mountable on a camera body having a camera side control circuit, the interchangeable lens comprising an aperture motor, an aperture operated by the aperture motor as a drive source, and an open state of the aperture. And a lens side control circuit for driving the aperture motor in response to communication from the camera side control circuit, the interchangeable lens being mounted on the camera body, and the lens side control circuit. When the diaphragm detection means does not detect the open state of the diaphragm when the camera side control circuit becomes communicable, the lens side control circuit communicates from the camera side control circuit. An interchangeable lens which receives the light and drives the diaphragm motor to open.