JP2004117380A - Camera system, camera, and accessory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of entailing enlarging size of accessories etc., with a method of providing a camera with a power source of a fixed voltage and of providing the camera with step-down circuits and boosting circuits by each of accessories. <P>SOLUTION: The camera 1 is provided with power source supply means 12 and 13 capable of supplying a plurality of power supply voltages varying from each other and is provided with a plurality of power source connecting terminals 9f and 9g in the positions different from each other in an accessory attachment section by each of the power supply voltages which are supplied from the power source supply means and vary from each other. The accessory 2 is provided with a power source input terminal 9 in the position connected only to the power source connecting terminal to which the power supply voltage corresponding to the operating voltage of the accessories among a plurality of the power source connecting terminals is supplied. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a camera system including a camera and accessories such as interchangeable lenses.
[0002]
[Prior art]
In an interchangeable lens camera system, the interchangeable lens is equipped with various actuator drive mechanisms such as an autofocus function and a zoom function, as well as their drive and control circuits, and various electronic circuits and control circuits are also mounted on the camera side. I have. The mount section for connecting the camera and the lens has a communication terminal for enabling communication between a control circuit in the camera and a control circuit in the interchangeable lens, and a power supply circuit mounted on the camera side. And an electric connection terminal such as a power supply terminal for supplying power from the camera to the interchangeable lens side.
[0003]
In such a system, contact failure of the electrical connection terminal poses a problem. To solve this problem, there is a connection confirmation method proposed in Patent Document 1. In this method, when the interchangeable lens is attached to the camera, the camera and the lens communicate first, and after confirming that the communication terminals are properly connected, power is supplied to the power terminal. is there.
[0004]
Further, in the camera system, there are various kinds of lenses mounted on the camera depending on optical specifications such as a focal length. The operating voltage (power supply voltage) of the lens also varies depending on the type and number of the built-in actuators. Conventionally, an actuator with a built-in lens is designed on the assumption that the operating voltage is 6 V. However, due to recent downsizing of interchangeable lenses and reduction in power consumption of a motor, for example, the operating voltage may be 3 V. .
[0005]
As described above, as means for mounting a plurality of interchangeable lenses having different required operating voltages (power supply voltages) on one camera, the power supply of the camera is set to a fixed voltage, and a step-down circuit and a step-up circuit are provided for each interchangeable lens. There is a method of providing. Patent Document 2 discloses a configuration in which a plurality of output voltages can be switched and supplied to one power supply connection terminal on the camera side, and the type of the attached interchangeable lens is determined by the state of a predetermined electric connection terminal. A method of discriminating and determining an output voltage to a power supply connection terminal has been proposed.
[0006]
[Patent Document 1]
Japanese Patent Publication No. 4-48374 [Patent Document 2]
JP-A-8-110561
[Problems to be solved by the invention]
However, the above-described method in which the power supply of the camera is set to a fixed voltage and the step-down circuit and the step-up circuit are provided for each interchangeable lens has a problem that the cost and size of each interchangeable lens are increased.
[0008]
Further, according to the method proposed in Patent Document 2, if a predetermined electrical connection terminal itself for determining an interchangeable lens has a connection failure, the interchangeable lens cannot be determined or the determination is erroneously replaced with a power supply terminal. Since a power supply voltage different from the operating voltage of the lens is supplied, there is a possibility that problems such as the inoperability of the interchangeable lens may occur.
[0009]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a camera system in which accessories having different operating voltages can be mounted on a camera, and a power supply of an appropriate voltage can be reliably supplied to the accessories mounted on the camera.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in a camera system including a camera having an accessory mounting portion and a plurality of accessories selectively mounted on the accessory mounting portion and having different operating voltages from each other, Is provided with power supply means capable of supplying a plurality of different power supply voltages, and a plurality of power supply connection terminals are provided for each of the different power supply voltages supplied from the power supply means and at mutually different positions in the accessory mounting portion. .
[0011]
The plurality of accessories are respectively connected to only the power supply connection terminals to which the power supply voltage corresponding to the operating voltage of each of the plurality of power supply connection terminals is supplied when the accessory is mounted on the accessory mounting portion. Provide a power input terminal.
[0012]
Thus, when the accessory is mounted on the camera, the power input terminal of the accessory is connected only to the power supply connection terminal of the camera to which the power supply voltage corresponding to the operating voltage of the accessory is supplied. For this reason, it is possible to mount accessories having different operating voltages on the camera, and it is possible to surely supply power of the required operating voltage to the accessories mounted on the camera without increasing the size of the accessories. This makes it possible to realize a camera system that has been described above.
[0013]
When communication is possible between the camera and the accessory attached to the camera, information indicating the operating voltage of each accessory is transmitted to the camera when the accessory is attached to the camera. Power supply control means for supplying only the power supply voltage corresponding to the operating voltage from the power supply means to the power supply connection terminal corresponding to the power supply voltage in accordance with the information representing the operating voltage. May be provided.
[0014]
The accessory according to the present invention includes an interchangeable lens that can be attached to and detached from a camera.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
FIG. 1 shows a configuration of an interchangeable lens camera system according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a digital camera; 2, a lens-side mount unit 20 that can be engaged with a camera-side mount unit (accessory mounting unit) 9; It is an interchangeable lens to be attached.
[0016]
Although not shown in FIG. 1, the present camera system includes a lens-side mount portion common to the interchangeable lens 2 and can be selectively mounted on the camera 1 and has different operating voltages (power supply voltages). A plurality of interchangeable lenses are included.
[0017]
First, the configuration of the camera 1 will be described. Reference numeral 3 denotes a camera-side electric circuit. The camera-side electric circuit unit 3 detects a light metering unit 4 for measuring an amount of light (brightness of a subject) that has passed through the interchangeable lens 2 and a focus adjustment state of a photographic optical system in the interchangeable lens 2. A focus detection unit 5, an image sensor 7 composed of a CCD, a CMOS sensor, or the like for photoelectrically converting an image of a subject formed by an image capturing optical system to capture an image, and controlling an exposure time (charge accumulation time) of the image sensor 7. And a camera CPU 8 that controls these circuits.
[0018]
The camera-side mount unit 9 is provided with electric connection terminals 9a to 9h for electrically connecting to electric connection terminals (which will be described later) on the interchangeable lens 2 side. Further, the camera-side mount unit 9 is provided with a lens attachment detection switch 9i.
[0019]
Of the electrical connection terminals 9a to 9h, 9a to 9c are communication terminals for performing serial communication with the interchangeable lens 2, and 9d and 9e are control system power supply connection terminals for supplying control system power to the interchangeable lens 2. is there. 9 f to 9 h are drive system power supply connection terminals for supplying drive system power to the interchangeable lens 2. These connection terminals 9 a to 9 h are arranged at different positions on the camera-side mount unit 9 (different positions in the circumferential direction of the mount unit 9). Note that among the control system power supply connection terminals 9d and 9e and the drive system power supply connection terminals 9f to 9h, 9e and 9h are ground terminals.
[0020]
The lens attachment detection switch 9i has two switch pieces. One of the switch pieces is connected to an output terminal of a control system power generation circuit 11 that outputs a predetermined constant voltage described later, and the other is connected to the camera CPU 8 and a power supply battery 10 described later via a resistance element. -Pull down connection to the pole.
[0021]
The lens attachment detection switch 9i has a configuration in which two switch pieces are separated when the interchangeable lens 2 is not attached, and is connected to the camera CPU 8 when the interchangeable lens 2 is attached. The switch piece on the side is at the GND level. Further, when the interchangeable lens 2 is mounted, the two switch pieces come into contact with each other. As a result, the switch piece connected to the camera CPU 8 becomes the output level of the control system power generation circuit 11.
[0022]
The control system power generation circuit 11 is connected to the power supply battery 10 and is provided to the control system circuit 21 on the interchangeable lens 2 side via the camera-side electric circuit 3 and the control system power supply connection terminals 9d (9e). Supply constant voltage.
[0023]
Reference numeral 12 denotes a first drive system power generation circuit (shown as a drive system power supply generation circuit 1 in the figure), which is connected to the power supply battery 10 and is connected to the interchangeable lens 2 via a drive system power supply connection terminal 9f (9h). A first level constant voltage is supplied to the drive system circuit 23 on the side as the drive system operating voltage. The camera system of the present embodiment particularly includes a plurality of interchangeable lenses whose operating voltages of the drive system are different from each other. In the present embodiment, the constant voltage supplied from the first drive system power generation circuit 12 to the drive system power supply connection terminal 9f is 6V.
[0024]
Reference numeral 13 denotes a second drive system power generation circuit (shown as a drive system power generation circuit 2 in the figure) which is connected to the power supply battery 10 and is connected to the interchangeable lens 2 via the drive system power supply connection terminal 9g (9h). A second level constant voltage is supplied to the driving system circuit 23 on the side as the operating voltage of the driving system. In the present embodiment, it is assumed that a constant voltage of 3 V is supplied from the second drive system power supply generation circuit 13.
[0025]
Next, the configuration on the interchangeable lens 2 side will be described. 14 is a focusing lens, 15 is a zooming lens, and 16 is a diaphragm. These form an imaging optical system.
[0026]
Reference numeral 17 denotes a brush for detecting a zoom position for detecting the position of the zooming lens 15, reference numeral 18 denotes a brush for detecting a focus position for detecting the position of the focusing lens 14, and reference numeral 19 denotes an A / M for switching between auto focus and manual focus. Switch.
[0027]
The lens-side mount section 20 is provided with electric connection terminals 20a to 20f and 20h so that the positions are different from each other. Of the electrical connection terminals 20a to 20h, 20a to 20c are communication terminals for performing serial communication with the camera 2, and when the interchangeable lens 2 is properly mounted on the camera 1, communication is performed on the camera 1 side. It faces and contacts the terminals 9a to 9c.
[0028]
Reference numerals 20d and 20e denote control system power input terminals for receiving control system power from the camera 1. When the interchangeable lens 2 is properly mounted on the camera 1, the control system power connection on the camera 1 side is performed. It faces and contacts the terminals 9d to 9e.
[0029]
Reference numerals 20f and 20h denote drive system power supply input terminals for receiving drive system power supply from the camera 1. When the interchangeable lens 2 is properly mounted on the camera 1, the drive system power supply terminals are provided on the camera 1 side. It faces and contacts the power supply connection terminals 9f to 9h.
[0030]
In addition, among the control system power supply input terminals 20d and 20e and the drive system power supply input terminals 20f and 20h, 20e and 20h are ground terminals.
[0031]
Here, the interchangeable lens 2 shown in FIG. 1 is designed to use 6 V as a drive system power supply (operating voltage). For this reason, the drive system power supply input terminal 9g corresponding to the drive system power supply connection terminal 9g for supplying 3V provided on the camera 1 side is not provided in the interchangeable lens 2 shown in FIG. The drive system power supply input terminal 9g and the drive system power supply input terminal 20f and the drive system power supply input terminal 9f and the drive system power supply input terminal 20g are connected to each other when the interchangeable lens 2 is properly mounted on the camera 1. Since the mechanical positions are different in the direction and the like, there is no contact.
[0032]
The control system circuit 21 in the interchangeable lens 2 is provided with a lens CPU 22 that controls each circuit in the interchangeable lens 2. A drive system circuit 23 in the interchangeable lens 2 includes an aperture drive circuit 24 for supplying a drive signal to an aperture drive motor 26 for driving the aperture 16 and a drive signal for a focus drive motor 28 for driving the focusing lens 14. Is provided.
[0033]
A pulse generator 27 outputs a pulse signal as the focusing lens 14 moves. The output signal from the pulse generator 27 is input to the lens CPU 22 and used for precise position control and speed control of the focusing lens 14.
[0034]
Next, a power supply operation in the camera system of the present embodiment will be described.
[0035]
<When the interchangeable lens 2 is not attached to the camera 1>
When the interchangeable lens 2 is not mounted on the camera 1, the lens-side mount portion 20 is separated from the camera-side mount portion 9, and the electrical connection terminals 9 a to 9 h and 20 a to 20 h of the two are not in contact with each other. In the lens detection switch 9i in the camera-side mount 9, the two switch pieces are separated. Therefore, as described above, one of the switch pieces connected to the camera CPU 8 is at the GND level. As a result, the camera CPU 8 determines that the interchangeable lens 2 is not mounted, and turns off the outputs of the first drive system power generation circuit 12 and the second drive system power generation circuit 13.
[0036]
<When interchangeable lens 2 is attached to camera 1>
When the interchangeable lens 2 is mounted on the camera 1, the electrical connection terminals 9a to 9h and 20a to 20h of the two come into contact with each other. Further, in the lens detection switch 9i in the camera-side mount 9, the two switch pieces are As a result, the one of the switch pieces connected to the camera CPU 8 becomes the output level of the control system power generation circuit 11 as described above.
[0037]
Hereinafter, the operation of the camera CPU 8 when the interchangeable lens 2 is mounted on the camera 1 will be described with reference to the flowchart shown in FIG.
[0038]
"STEP1"
The camera CPU 8 detects the level of a switch piece of the lens detection switch 9i in order to determine whether or not the interchangeable lens 2 is mounted. If the level of the switch piece is the GND level, STEP 1 is repeated every predetermined time assuming that the interchangeable lens 2 is not mounted. If the level of the switch piece is the output level of the control system power generation circuit 11, it is determined that the interchangeable lens 2 is mounted, and the process proceeds to STEP2.
[0039]
"STEP2"
The camera CPU 8 performs serial communication with the lens CPU 22 via the communication connection terminals 9a to 9c and 20a to 20c, and checks the electrical connection status. If the connection can be confirmed, the process proceeds to STEP3. If the connection cannot be confirmed, serial communication is performed again to confirm the electrical connection again.
[0040]
Here, as serial communication for confirming the electrical connection, for example, when command data A for confirming the connection is transmitted from the camera CPU 8, and when the lens CPU 22 confirms the command data A and transmits predetermined data B, The camera CPU 8 confirms connection with the interchangeable lens 2 by receiving the predetermined data B. Further, the lens CPU 22 confirms the connection with the camera 1 by receiving the command data A.
[0041]
"STEP3"
The camera CPU 8 performs serial communication with the lens CPU 22, confirms a valid drive system power supply connection terminal, and proceeds to STEP4. For example, the camera CPU 8 transmits command data C for confirming a valid drive system power supply connection terminal, and the lens CPU 22 confirms the command data C and transmits predetermined data D indicating a valid drive system power supply connection terminal. I do. For example, the predetermined data D is "01" if the drive system power supply shown in FIG. 1 is the interchangeable lens 2 of 6V specification and the corresponding drive system power supply connection terminal and input terminal are 9f and 20f, Unlike the interchangeable lens shown in FIG. 1, if the drive system power supply is an interchangeable lens of 3V specification and the corresponding drive system power supply connection terminal and input terminal are 9 g and 20 g, the value is set to “02”.
[0042]
"STEP4"
The camera CPU 8 determines which of the first drive system power generation circuit 12 and the second drive system power generation circuit 13 to operate based on the data D received from the lens CPU 22 in STEP3. If the data D is "01", the process proceeds to STEP5, and if the data D is "02", the process proceeds to STEP6. If the data D is not "01" or "02", it is determined that the communication for confirming the valid drive system power supply connection terminal has failed in STEP3, and the process returns to STEP3. Note that, as indicated by the dotted line in FIG. 2, the process may return to STEP 2 and confirm the electrical connection again.
[0043]
"STEP5"
The camera CPU 8 operates the first drive system power supply generation circuit 12 to cause the drive system circuit 23 on the interchangeable lens 2 side to have a first level constant voltage (6 V) via the drive system power supply connection terminal 9f and the input terminal 20f. Supply).
[0044]
"STEP6"
The camera CPU 8 operates the second drive system power supply generation circuit 13 and supplies a second level constant voltage (3 V) to the drive system circuit on the interchangeable lens side (not shown) via the drive system power supply connection terminal 9g and the input terminal 20g. Supply).
[0045]
As described above, in the present embodiment, in a camera system including a camera and an interchangeable lens that can be attached to and detached from the camera, the camera is provided with a drive system power generation circuit having a plurality of voltage levels, The output of the generation circuit is supplied to the interchangeable lens via a set of the drive system power supply connection terminal and the drive system power supply input terminal whose position is different for each power supply voltage. A power supply voltage different from a required operating voltage is not supplied.
[0046]
Furthermore, since the drive system power supply voltage required for the interchangeable lens is determined by data communication in the camera, and only the drive system power supply generation circuit that generates the drive system power supply voltage is operated, it is effective for power saving of the camera. It is.
[0047]
Thus, it is possible to realize a camera system that does not increase the price and size of the interchangeable lens and that does not accidentally supply a different power supply voltage from the camera to the interchangeable lens.
[0048]
(2nd Embodiment)
In the above-described first embodiment, a case has been described in which the drive system power supply generation circuits 1213 that respectively generate different drive system power supply voltages are separately provided. However, as shown in FIG. A system power supply generation circuit 31 is provided, and the supply destination (drive system power supply connection terminals 9f, 9g) of the power supply voltage from the drive system power supply generation circuit 31 is switched by the switching elements 32, 33 according to the set power supply voltage. You may do so.
[0049]
The other configuration of the camera system of the present embodiment is the same as that of the first embodiment.
[0050]
In each of the above embodiments, a camera system in which a lens as an accessory can be replaced with a camera has been described. However, the present invention is also applied to a camera system in which other accessories such as a strobe device can be replaced. be able to.
[0051]
【The invention's effect】
As described above, according to the present invention, it is possible to mount accessories having different operating voltages from each other on a camera. It is possible to realize a camera system capable of supplying a power supply having a high operating voltage.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a camera system according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing a power supply operation of the camera system.
FIG. 3 is a block diagram illustrating a configuration of a camera system according to a second embodiment of the present invention.
[Explanation of symbols]
1 camera 2 interchangeable lens 8 camera CPU
9 Camera-side mount unit 10 Power supply 11 Control system power supply generation circuit 12 First drive system power supply generation circuit 13 Second drive system power supply generation circuit 20 Lens-side mount unit 21 Control system circuit 22 Lens CPU
23 Drive system circuit

Claims (8)

A camera system including an accessory mounting portion and a plurality of accessories selectively mounted on the accessory mounting portion and having different operating voltages.
The camera is
Power supply means capable of supplying a plurality of different power supply voltages,
A plurality of power supply terminals provided for each of different power supply voltages supplied from the power supply means, and provided at different positions in the accessory mounting portion;
Each of the plurality of accessories,
A power input terminal is provided at a position connected to only a power supply terminal to which a power supply voltage corresponding to an operation voltage of each accessory is supplied among the plurality of power supply connection terminals when mounted on the accessory mounting portion. Camera system characterized by the following. The accessory is an interchangeable lens,
In the camera, the plurality of power connection terminals are provided on a camera-side mount portion on which the interchangeable lens is mounted,
2. The camera system according to claim 1, wherein in the interchangeable lens, the power input terminal is provided on a lens-side mount mounted on the camera. 3. Communication between the camera and the accessory attached to the camera is possible,
Each of the accessories has information transmission means for transmitting information representing an operating voltage of each accessory to the camera when the accessory is attached to the camera,
The camera includes a power supply control unit that supplies only a power supply voltage corresponding to the operation voltage from the power supply unit to the power supply connection terminal corresponding to the power supply voltage in accordance with information indicating the operation voltage. The camera system according to claim 1 or 2, wherein A camera having an accessory mounting portion, wherein the accessory mounting portion can be mounted with a plurality of accessories having different operating voltages from each other,
Power supply means capable of supplying a plurality of different power supply voltages,
A camera, comprising: a plurality of power supply connection terminals provided for different power supply voltages supplied from the power supply means, and provided at different positions in the accessory mounting portion. 2. The camera according to claim 1, wherein the plurality of power connection terminals are provided on a camera-side mount unit to which an interchangeable lens as an accessory is mounted. 3. Communication with the attached accessory is possible,
Power control for supplying only the power supply voltage corresponding to the operating voltage from the power supply means to the power supply connection terminal corresponding to the power supply voltage in accordance with the information received from the attached accessory and representing the operating voltage of the accessory The camera according to claim 4 or 5, further comprising means. Power supply means capable of supplying a plurality of power supply voltages different from each other, and a plurality of power supply connection terminals provided for each of the different power supply voltages supplied from the power supply means are provided at different positions in the accessory mounting portion. An accessory that is detachably attached to the camera,
A power input terminal is provided at a position connected to only a power supply terminal to which a power supply voltage corresponding to an operating voltage of the accessory is supplied among a plurality of power supply connection terminals on the camera side when the accessory is mounted on the accessory mounting portion. An accessory characterized by being provided. It is an accessory as an interchangeable lens,
The accessory according to claim 7, wherein in the interchangeable lens, the power input terminal is provided on a lens-side mount portion mounted on the camera.

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