JP3135258B2 - Interchangeable lens system - Google Patents

Description

The present invention relates to a power supply system suitable for use in video equipment such as a video camera system with interchangeable lenses.

(Prior Art) In recent years, the progress of video equipment such as video camera systems has been remarkable, and especially in video cameras and video recorder systems with integrated cameras, replacement of various types of lenses has become possible. A lens system has been proposed and its function has been improved.

By the way, as an interchangeable lens system,
Interchangeable lens systems (still camera systems) for single-lens reflex cameras are widely and generally known, and various lenses have already been supplied to the market, including special lenses adapted to various uses.

However, in the video camera system, it is still in its introductory period, and the market is still untapped, and in the initial stage, it is not realistic to manufacture other types of special lenses that should be the characteristics of the interchangeable lens system, From the user's point of view, if the interchangeable lens for SLR cameras currently on the market can be shared with video cameras,
It is very convenient, and with the spread of video cameras in recent years, there has been an increasing demand for using interchangeable lenses for single-lens reflex cameras in video cameras.

Therefore, a conversion adapter for connecting a camera for a video camera and a lens for a still camera is required.

This conversion adapter matches (1) the mount in the interchangeable lens system for video cameras and the mount in the interchangeable lens system for still cameras are different.

(2) Since the distance between the image pickup surface of the video camera and the still camera and the mount position are different, the optical path difference is adjusted.

(3) The communication format specified for transferring various data required for control differs between the interchangeable lens system for video cameras and the interchangeable lens system for still cameras, and the data format / control format is different. Take that alignment.

Are required for three reasons:

(Problems to be Solved by the Invention) In an interchangeable lens system for a video camera, a power supply element is usually supplied to the lens side from a battery or an AC adapter connected to the video camera through electrical contacts of the camera mount. You.

Since a video camera usually uses a drive circuit (such as a motor) that requires a large amount of power continuously, it is necessary to set a certain limit on the power supplied to the lens in view of the battery specification time.

On the other hand, in a still camera system, since a drive circuit (a motor or the like) requiring a large amount of power is not continuously used, the limitation on the power is relatively gradual.

Therefore, when the still camera lens is connected to the video camera and used, there is a possibility that the lens needs more power than the maximum power supply capability of the video camera interchangeable lens system.

Therefore, it is conceivable that the conversion adapter has another power supply element (such as an external battery) to compensate for the shortage.

However, in such a case, no problem occurs when the conversion adapter is connected to the video camera, but the conversion adapter is not connected to the video camera, and the still camera lens is connected to the conversion adapter. In this case, there arises a problem that the power from the power supply element connected to the conversion adapter is supplied to the lens side and is wasted. In particular, if the battery is left as it is, the battery cannot be used (discharge ends).

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and according to the invention described in claim (1), a lens unit and a first lens unit are provided. A camera body provided with power supply means, an adapter device connecting the camera body and the lens unit, and supplying power to the lens unit from the first power supply means in the camera body. A second power supply unit capable of supplying power via the adapter device and independently of the first power supply unit in the camera body, and when the camera body is connected to the adapter device And a control means for enabling the power from the second power supply means to be supplied to the lens unit.

According to the invention described in claim (2) of the present application, the first
Is connected to a first control device having power supply means and a second control device receiving power supply, and is capable of supplying power from the first power supply means to the second control device. An adapter device, wherein power can be supplied from a second power supply means that can be controlled independently of the first control device via the adapter device, and the first control device The present invention is characterized in that the adapter device is provided with control means for enabling power from the second power supply means to be supplied to the second control device only when the adapter device is connected to the adapter device.

Further, according to the invention described in claim (3) of the present application, in the invention described in claim (1), the adapter device is for allowing a lens unit having a control method different from that of the camera body to be mounted. An interchangeable lens system having a mount conversion unit that converts a mount portion of the camera body and the lens unit is characterized.

According to the invention of claim (4) of the present application, in the invention of claim (3), the adapter device controls the control information output from the camera body side and controls the actuator of the lens unit side. The interchangeable lens system is provided with a data conversion means for converting the status information output from the lens unit into a signal format for the camera body, while converting the status information into a signal format for the camera unit.

According to the invention of claim (5) of the present application, in the invention of claim (4), the actuator on the lens unit side is at least one of a focus lens drive unit, an aperture drive unit, and a zoom lens drive unit. The data conversion means converts the control information output from the camera body into a signal format that can control each of the actuators, and converts the status information of the drive unit into a signal format on the camera body. Features an interchangeable lens system configured to convert.

According to the invention of claim (6) of the present application, in the invention of claim (1) or (5), the camera body is a video camera, and the lens unit is
It is characterized by an interchangeable lens system that is a still camera lens that is not control compatible with the video camera alone.

According to the invention described in claim (7) of the present application, in the invention described in claim (2), the control information output from the first control device side is further transmitted to the second control device. The adapter device is provided with data conversion means for converting the data into a signal format for controlling the drive unit on the side.

Further, according to the invention described in claim (8) of the present application, in the invention described in claim (7), the data conversion means further outputs status information output from the second control device side. An adapter device configured to convert to a signal format of the first control device is characterized.

(Operation) According to the invention described in claim (1), even if a lens unit consuming a large amount of power is mounted, a large power supply for the purpose is not always built into the camera body, and power is supplied by an intermediate adapter. If the camera body is not connected to the adapter, the power supply from the external power supply is stopped, and even if the camera body is left unattached, power from another power supply can be consumed. Absent.

According to the invention of claim (2), even if the power consumption of the second control device is large, a large power supply for the first control device is not always built in, and power is supplied by the intermediate adapter. Becomes possible. In addition, when the first control device is not connected to the adapter, the power supply from the external power supply is stopped, and even when the first control device is left unattached without being attached, the power of another power supply is supplied. There is no consumption.

(Example) Hereinafter, an example of an interchangeable lens system according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of an interchangeable lens system according to the present invention.

In the figure, 301 is a video camera body as a first control device, 101 is a still camera interchangeable lens (hereinafter simply referred to as a lens) as a second control device, and 201 is a video camera body 301 with a single-lens reflex camera. This is a conversion adapter for attaching a lens.

Reference numeral 401 denotes an external battery connected to the conversion adapter 201.

The video camera body 301 and the conversion adapter 201 are mechanically mounted by a mount (not shown), and various kinds of control information for controlling the lens 101 are transmitted from the video camera body to the conversion adapter 201, and the conversion adapter 20
The bidirectional communication line 60 for receiving a status signal indicating the operating state of the lens returned from the lens side from 1
1 electrically connected. This communication line 601
Includes a power line for supplying power from the camera side to the lens side, and a GND line.

Similarly, conversion adapter 201 and still camera lens 1
01 is also mechanically connected by a mount (not shown) and electrically connected by a bidirectional communication line 501, and is bidirectional for camera-side control information and lens-side status signals supplied via a conversion adapter. Communication is performed.
It goes without saying that the communication line 501 also includes a power supply line and a GND line.

That is, as shown in FIG. 2, each of the communication lines 501 and 601 includes data communication lines 501a and 601a for performing data communication such as control information and status information, and power supply and GND lines 501b and 601b for supplying power.

The conversion adapter 201 and the external battery 401 are connected by an electric signal line 701. The connection line 701 includes a power supply line and a GND line.

Note that the power supply connection line 701 may actually use the same power supply line as the power supply line 601b.

FIG. 2 is a block diagram showing a specific configuration of the interchangeable lens system according to the present invention.

The same reference numerals are used for the same components as in FIG. 1, but the power supply line and the control signal communication line are shown separately for convenience of explanation.

In the lens 101, a focusing lens 102 for performing focus adjustment, a lens group including a zoom lens 103 for varying the magnification and performing zooming, an aperture 104, a relay lens 105, and the like are arranged, and a focusing lens, Driving units 106, 107, and 108 each including a zoom lens, a motor for driving an aperture, and a driving circuit are provided. These drive units are driven and controlled based on control information from the camera supplied from the conversion adapter 201 via the communication line 501 by the control microcomputer 109 which performs overall control of the lens. Is done.

The operating states of the focusing lens, zoom lens, and aperture are detected by the focus encoder 110, the zoom encoder 111, and the aperture encoder 112, respectively, captured by the lens-side microcomputer 109, and subjected to predetermined processing as necessary. After that, the data is transmitted to the conversion adapter via the communication line, and then supplied to the camera.

On the other hand, the conversion adapter 201
For photoelectrically converting the subject image formed by the lens 101 connected through the
An image sensor 302 such as a CCD, a preamplifier 303 that amplifies a video signal output from the image sensor 302 to a predetermined level, a predetermined process such as a predetermined gamma correction, a blanking process, and a synchronization signal addition to an output signal of the preamplifier 303. Signal processing circuit that converts the signal into a standardized television signal and outputs it
304, an AF circuit 305 that detects a focus state based on a high-frequency component of the luminance signal from the video signal, compares the average value of the luminance signal level of the video signal with a preset reference level, and sets the luminance signal level to the reference level. An AE circuit 306 that outputs a signal for controlling the aperture so that it is always equal, a control microcomputer (referred to as a camera microcomputer) 307 that controls and controls all functions of the video camera,
A zoom switch 308 and the like for generating a command for operating the zoom lens are provided.

Focus state detection signal output from AF circuit 305, AE circuit 3
Aperture status detection signal output from 06, zoom switch 30
8 operation signals are supplied to the camera microcomputer 307, respectively.
A predetermined operation is performed with reference to the operation state information returned from the lens side via the conversion adapter 201, the data is converted into a format to be supplied to the lens side, and then converted via the communication line 601. Supplied to.
Then, it is converted into the control data format of the still camera lens, transmitted to the lens 101 side via the communication line 501,
Control of the lens is performed.

309 is a power supply built in the video camera side,
An electric or mechanical switch 310, which is ON / OFF controlled by the camera microcomputer 307, controls whether or not to supply power to the lens side or the conversion adapter to the outside.

Here is a brief explanation of each function.
A high-pass filter 305a extracts a high-frequency component of a luminance signal in a video signal that changes according to a focus state, detects the high-frequency component by a detection circuit, converts the high-frequency component into a DC level, and outputs the DC signal to a peak hold circuit 305b. The peak value is detected at predetermined intervals, converted into a digital signal by the AD conversion circuit 305c, and supplied to the camera microcomputer 307. Camera microcomputer 307
Then, the peak value of the high frequency component is detected every predetermined period,
The control information for driving the focusing lens in the direction in which the value becomes maximum is calculated while considering the depth of field with reference to the aperture information from the lens side, and is converted according to the lens side, that is, according to the present embodiment. Output to adapter 201.

The AE circuit 306 integrates the luminance signal component YC separated by a low-pass filter or the like in the signal processing circuit into an integrating circuit.
The light amount information obtained by integration in 306a is compared with a preset reference amount level by a comparison circuit 306b, the information of the difference is converted into a digital signal by an AD conversion circuit 306c, and supplied to a camera microcomputer 307. A control signal for driving the aperture is generated so that the luminance signal level matches the reference amount level.

On the lens side, the diaphragm driving unit in the lens is driven based on the control signal, and as a result, the amount of light input to the camera side changes, and a control loop is formed so that the proper aperture value is finally obtained. You.

The conversion adapter 201 performs all control in the adapter, receives various control information transmitted from the camera side via the communication line 601a, converts the control information into a data format compatible with the lens side, An adapter microcomputer 202 for outputting to the lens side via 501a is provided.

At this time, the power supplied from the power supply 309 on the video camera side via the communication line 601b is transmitted to the communication line 501b.
Is supplied to the lens side.

The adapter microcomputer 202 also receives various status information returned from the lens side via the communication line 501a, converts the status information into a data format compatible with the camera side,
Output to the camera side via the communication line 601a.

203 is an external battery 40 connected to the conversion adapter 201
1 is turned on and off based on a command from the adapter microcomputer 202, and a lens 1 for a still camera is provided by an external battery 401.
This switch controls the power supply to 01, and is set to be open when the adapter microcomputer is not operating.

The power of the external battery 401 is supplied to the power supply line 7.
It is supplied to the lens side via 01.

The above-mentioned power supply lines are electrically connected to all the power supply lines to be controlled in the unit as well as the respective microcomputers, and supply power to them. A description will be given by using the connection of the power supply line between them.

In addition, since control of a control target in a video camera is usually complicated, control is often performed using a plurality of microcomputers in many cases. However, in the present embodiment, for the sake of convenience of explanation, an electric signal of a conversion adapter is used. Paying attention to the delivery, each is controlled by one microcomputer.

The interchangeable lens system according to the present invention has the above-described configuration. Next, the power supply control operation will be particularly described.

First, when the video camera body 301 exists alone, the function of the camera is to supply power to the conversion adapter 201 and the lens 101 via the electric signal line 601 because the lens is not connected. No need.

Further, in this case, since the electrical contacts to which the lens or the conversion adapter is connected are exposed to the outside, the camera microcomputer 307 opens the switch 310 and does not supply power to the outside.

On the other hand, when a lens or a conversion adapter is connected to the video camera main body 301, it is necessary to supply power to the outside, so the camera microcomputer 307 short-circuits the switch 310 and the power supply 309 in the video camera. Is supplied to the outside.

On the other hand, when the conversion adapter 201 is connected to the video camera main body 301, the power supplied from the power supply 309 in the video camera 301 to the conversion adapter 201 through the switch 310 and the electric signal line 601b is supplied to the adapter microcomputer 202.
(In fact, it is usual to have a regulator in the adapter to stabilize the voltage to the microcomputer.)

When this power is supplied, the adapter microcomputer 202 starts operating.

When the still camera lens 101 is not connected to the conversion adapter 201, it is not necessary to supply power to the electric signal line 501 because the lens is not connected as a camera function.

Furthermore, in this case, since the electrical contact portion to which the lens is connected is exposed to the outside, the adapter microcomputer 202
03 is open and no power is supplied to the outside, that is, the lens side.

On the other hand, when a lens is connected to the conversion adapter 201, it is necessary to supply power to the outside, so the adapter microcomputer 202 short-circuits the switch 203 and the power is externally connected from the external battery 401. Supply to the lens.

Next, when the still camera lens 101 is connected to the conversion adapter 201 and the video camera body 301 is not connected, the switch 203 is opened because power is not supplied to the adapter microcomputer 202. No power is supplied to the lens side. Therefore, when the conversion adapter 201, the still camera lens 101, and the external battery 401 are connected, the power of the external battery 401 is not wasted.

This is a very effective means in an interchangeable lens system, since it is easy to forget to turn on and off the power of the lens when the lens is usually removed from the camera.

According to the above-described embodiment, when a still camera lens or the like having large power consumption is mounted on the video camera body via the conversion adapter, the communication lines 501b and 701 for power supply are provided on the lens side, respectively. By using, the power can be supplied from both the power supply of the video camera body and the external battery connected to the conversion adapter, but the line 501b is omitted and the still camera lens is attached by the conversion adapter Alternatively, power may be supplied only from the external battery of the conversion adapter.

(Effect of the Invention) As described above, according to the interchangeable lens system of the present invention, if power cannot be supplied directly because the lens requires large power, an adapter having a separate power supply element in the middle is used. Intervening solves the problem of power supply, and automatically disconnects the power supply of another power supply element when it is removed from the camera as the main control device in such a system and left unattended. As a result, wasteful power consumption can be prevented, and the effect is extremely large in an interchangeable lens system.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an interchangeable lens system according to the present invention, and FIG. 2 is a block diagram illustrating a specific configuration of the interchangeable lens system according to the present invention.

Claims (8)

(57) [Claims] A lens unit, a camera body including a first power supply unit, the camera body and the lens unit connected to each other, and the lens unit is connected to the lens unit by the first power supply unit in the camera body. An adapter device capable of supplying power to the camera; a second power supply unit capable of supplying power via the adapter device and independently of a first power supply unit in the camera body; An interchangeable lens system comprising: a control unit configured to supply power from the second power supply unit to the lens unit only when the main body is connected to the adapter device. 2. A power supply system, comprising: a first control device having first power supply means; and a second control device receiving power supply, wherein the power from the first power supply means is supplied to the second control device. An adapter device that can be supplied to the control device of the above, wherein power can be supplied from a second power supply unit that can be controlled independently of the first control device via the adapter device, Control means for enabling the power from the second power supply means to be supplied to the second control device only when the first control device is connected to the adapter device. Adapter device. 3. The adapter device according to claim 1, wherein the adapter device is for mounting a lens unit having a control method different from that of the camera body, and converts a mount portion of the camera body and the lens unit. An interchangeable lens system comprising a mount conversion unit. 4. The lens unit according to claim 3, wherein the adapter device converts control information output from the camera body into a signal format for controlling an actuator on the lens unit side, and An interchangeable lens system comprising data conversion means for converting status information output from the camera into a signal format of the camera body. 5. The camera according to claim 4, wherein the actuator on the lens unit side is at least one of a focus lens drive section, an aperture drive section, and a zoom lens drive section, and the data conversion means is provided on the camera body side. It is configured to convert control information output from the controller into a signal format that can control the actuators, and convert status information of the driving unit into a signal format on the camera body side. Interchangeable lens system. 6. The camera according to claim 1, wherein the camera body is a video camera, and the lens unit is a lens for a still camera that is not control compatible with the video camera alone. An interchangeable lens system characterized by the following. 7. The data according to claim 2, further comprising: converting control information output from the first control device into a signal format for controlling a drive unit on the second control device. An adapter device comprising conversion means. 8. The data conversion means according to claim 7, wherein said data conversion means further converts status information output from said second control device into a signal format of said first control device. An adapter device characterized by being performed.