JP2530597B2 - camera - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a camera to which a lens barrel (hereinafter referred to as an AF lens) for automatic focus adjustment can be attached.

(Background of the Invention) In some conventional cameras, an AF lens is mounted and a signal from the camera guides the AF lens to a focused state. If you try to attach a newly developed AF lens to such a camera or attach an optical member (non-AF lens) that is manually adjusted in focus, you have to change the configuration on the camera side. It causes the inconvenience of not becoming.

(Object of the Invention) The present invention solves these drawbacks, and it is possible to selectively mount (use) at least two different types of optical members, and perform control according to each type of optical member. The purpose is to provide a camera.

(Example) In FIG. 1, (A) is a camera, (B) is a newly developed AF lens, (C) is a conventional AF lens,
(D) shows a conventional lens barrel that is not an AF lens.

The camera (A) shown in FIG. 1 has a terminal 1a for power supply and a terminal 1b for signal transmission on the mount surface on which the lens barrel is mounted.
~ 1d, has a ground terminal 1e. The coupling 2 is rotated by a motor 7 in the camera, which will be described later, and is provided so as to project on the mount surface of the camera.
The switching circuit 3 includes an output voltage to the terminal 1a and a signal transmission terminal 1b to
Switch the signal transmitted to 1d. The motor drive signal generation circuit 4 is a circuit that generates a motor drive signal for the conventional AF lens. The light receiving element 5 is a light receiving element for focus adjustment, which receives the transmitted light of the mounted lens. The CPU 6 discriminates whether the lens attached to the camera (A) is the new AF lens (B), the old AF lens (C), or the non-AF lens (D),
It receives a signal from the light receiving element 5 to identify the focus adjustment state of the lens, and outputs a signal for driving to the motors 7 and 15. The rotary plate 8 rotates together with the motor 7,
It has a transmissive portion 8a and a light shielding portion 8b. The light emitted from the light emitting element 9 reaches the light receiving element 10 via the rotating plate 8. The new AF lens (B) has a CPU 12, a coupling 13 that engages with the coupling 2, and a terminal 14a that is connected to each of the terminals 1a to 1e.
Having ~ 14e. These are provided on the lens side mount surface. The CPU 12 is supplied with power from the camera side through the terminals 14a and 14e, and the amount of movement of the lens element in the AF lens when the couplings 2 and 13 make one rotation and the movement of the lens element in the camera Data about the relationship with the amount of movement of the image plane (data unique to the interchangeable lens) is supplied to terminal 14b
Output to ~ 14d. Here, terminal 14d is attached to the lens (CPU6
Before the signal is exchanged between the CPU12 and the CPU12), it is in an open state. The old AF lens (C) has a motor 15
It has a motor drive circuit 16 and terminals 17a to 17e connected to the terminals 1a to 1e, respectively. The terminals 17a to 17e are provided on the lens side mount surface. The motor drive circuit 16 is supplied with power from the camera side via terminals 17a and 17e,
The motor drive signal is received via 17b to 17d to control the motor 15. In this lens, a motor 15 drives the lens elements within this lens. The rotary plate 18 rotates together with the motor 15. The rotating plate 18 and the elements 19, 20 are those on the camera side 8, 9,
It has the same configuration as 10. However, in any of the interchangeable lenses, the old AF lens (C) is set so that the amount of movement of the image plane accompanying the movement of the lens element and the amount of rotation of the motor 15 have a predetermined relationship. In the old AF lens, terminal 17d
Is connected to the ground via the resistor 21 in any lens, and when the lens is attached (before the motor 15 is driven)
Output low level. Conventional lens not for AF (D)
Does not have a terminal connected to the terminals 1a to 1e on the camera side. Then, the lens element is moved by a manually operated ring (distance ring) not shown.

Next, the lens identifying operation and the subsequent operation will be described using the flow chart of FIG.

(I) When the new AF lens is attached; When the lens (B) is attached, the signal from terminal 14d (open)
Is input to the port P ₀₁ of the CPU 6 via the terminal 1d. Then, in step S6, the CPU 6 determines whether or not the signal applied to the port P ₀₁ is at the Low level. With this lens,
Since the terminal 14d is in an open state, NO is determined. P ₀₁ is Low
If it is at the level, it is the old AF lens (C), so that the determination of NO means determination of the other lens. If NO is determined in the step, the process proceeds to step. In this step, the CPU 6 outputs a signal asking whether it is possible to communicate with the terminals 1b to 1d via the data bus 6a and the switching circuit 3. In this case, the lens (B) has a CPU 12, C
Since it is possible to communicate with PU6, the CPU 12 outputs a response signal to the terminals 14b to 14d. And this signal is sent to terminals 1b-1d, circuit 3,
It is transmitted to the CPU 6 via the data bus 6a. At step S6, the CPU 6 determines whether or not a response signal is received from the lens (B). In this case, since there is a response signal from the CPU 12, it is determined to be YES. If NO is determined here, the lens barrel is a conventional lens barrel that is not an AF lens. YE in step
At the time of S, it is determined in step that the attached lens is a new AF lens. Then, the CPU 6 sends a signal to the switching circuit 3 via the line 6b in step to instruct to switch the output voltage Vcc of the switching circuit 3 to 5V. In response to this, the switching circuit 3 switches the output voltage Vcc to 5V, and the terminal 1a
Will output this to.

After that, the processing shifts to another routine not shown, and the data relating to the movement amount of the lens element in the AF lens and the movement amount of the image plane described above are transferred from the CPU 12 to the terminals 14b to 14d, 1b to 1d, the circuit 3 and the data bus 6a. It is read into CPU6 via. This data is then used when performing automatic focusing.

Next, the operation of automatic focus adjustment will be described. Light from the subject is guided to the light receiving element 5 via the lens element of the lens (B). The light receiving element 5 generates a photoelectric output corresponding to the focus adjustment state of the lens element. The CPU 6 receives this photoelectric output and identifies the focus adjustment state. That is, the actual shift amount between the film surface and the image surface on which the subject image is formed, the front focus, and the rear focus are identified. Then, the CPU 6 detects the amount of deviation between the film surface and the image surface and the CPU 1 through the terminals 14b to 14d.
From the data on the lens movement amount and the image plane movement amount obtained from 2, the number of rotations of the coupling 2 must be calculated in order to make the above-mentioned displacement amount zero (to bring it into a focused state). Calculates how many rotations the motor 7 must make. The motor 7 is driven in the rotation direction corresponding to the front pin signal or the rear pin signal of the CPU 6. The rotation of the motor 7 is transmitted to the coupling 2, and is transmitted to the lens side through the coupling 13 engaging with the coupling. The lens element in the lens is thereby moved in the optical axis direction, and the image plane is moved in a direction coinciding with the film plane. The CPU 6 counts the pulses output to the emitter of the light receiving element (phototransistor) 10 along with the rotation of the rotary plate 8 through the port P _02, and calculates the rotation amount of the motor 7 as the rotation amount of the motor calculated as described above. Determines whether or not has reached. When it detects that the rotation amount has been reached, the motor 7 is stopped. In this way, the focused state is obtained.

(Ii) if the old AF lens is mounted; lens (C) When is mounted terminal 17d of the signal (Low level) is input through the terminal 1d to the port P ₀₁ of the CPU 6.
Then, at step S6, the CPU 6 determines whether or not the signal applied to the port P ₀₁ is at the low level, and determines YES. Therefore, the CPU 6 determines that the lens attached in step is the old AF lens. Next, the CPU 6 shifts to a step and sends a signal to the switching circuit 3 through the line 6b to instruct the switching circuit 3 to switch the output voltage Vcc to 3V. In response to this, the switching circuit 3 switches the output voltage Vcc to 3V, and the terminal 1a
Will output this to.

This lens does not have a CPU, so terminal 17b
17d does not output the same output as the terminals 14b to 14d, that is, the data regarding the lens movement amount and the image plane movement amount.

Next, the automatic focus adjustment operation will be described. Also in the case of this lens (C), the subject light is guided to the light receiving element 5 via the lens element in the lens (C), and the light receiving element 5 generates a photoelectric output corresponding to the focus adjustment state of the lens element. CPU6
Identifies the focus adjustment state from this. Up to now, the process is similar to that of the lens (B). But in this case CPU6 is the old AF
Since it is detected that the lens (C) is attached, the motor 7, the rotary plate 8, and the elements 9 and 10 are not driven. Then, only the identification signals of the front pin and the rear pin are output and transmitted to the motor drive signal generation circuit 4. The motor drive signal generation circuit 4 converts the signal from the CPU 6 into a signal for driving the motor 15, and this signal is passed through the switching circuit 3 to the terminals 1b ...
Output to 1d. That is, the switching circuit 3 receives the power supply voltage from the CPU 6.
When the Vcc switching signal is received, the path for communication between the CPUs 6 and 12 is cut off, and the signal from the motor drive signal generating circuit 4 is switched to be output to the terminals 1b to 1d. The motor drive circuit 16 receives the signal from the circuit 4 and rotates the motor 15, and the motor 15 moves the lens element in the optical axis direction. Then, the image plane moves in a direction coinciding with the film plane. When the rotary plate 8 rotates together with the motor 15, a pulse output is generated in the emitter of the light receiving element (phototransistor) 20, and this output is output via the terminals 17d and 1d to the port P _{01 of the} CPU 6.
Is transmitted to As described above, since the rotation amount of the motor 15 and the movement amount of the image plane are set to have a predetermined relationship, the pulse output and the movement amount of the image plane have the same relationship. Further, the CPU 6 also calculates the actual amount of deviation between the film surface and the image surface on which the subject image is formed when the front pin and rear pin signals are output to the motor drive signal generation circuit 4 as described above. Therefore, the CPU 6 counts the pulses input to the port P ₀₁ , obtains the image plane movement amount from this, and determines whether or not the image plane movement amount matches the actual shift amount. When it is determined that the two match, a signal for stopping the motor 15 is output to the motor drive signal generation circuit 4. In this way, the motor 15 is stopped and the in-focus state is obtained.

(Iii) When a conventional lens that is not an AF lens is attached; When the lens (D) is attached, the CPU 6 tries to read the output of the lens side terminal via the terminal 1d. However, since the lens (D) has no terminal, the state of the terminal 1d is in the open state as in the case of the lens (B). Therefore, the CPU 6 determines NO when it determines whether or not the signal of the port P ₀₁ is at the Low level in step. Then, the process proceeds to step, and a signal asking whether or not communication is possible is output via the terminals 1b to 1d. In this case, since the lens (D) does not have the CPU 6, no response signal is returned from the lens (D). Therefore, the CPU 6 determines in step that there is no response signal, and outputs a determination output as NO. Then, in step, it is determined that the mounted lens is a conventional lens that is not an AF lens. After that, the CPU 6 proceeds to step and sends a signal to the switching circuit 3 through the line 6b to issue a command to set the output voltage Vcc of the switching circuit 3 to zero. Then, the switching circuit 3 sets the output voltage Vcc to zero. That is, the power is turned off.

The subsequent focus adjustment is performed by manually operating the manual operation ring provided on the lens (D). Of course, the CPU6, CPU12
The signal for communicating with and the signal for driving the motor 15 are not output. Then, the switching circuit 3 is also in a state of shutting off all signals transmitted to the terminals 1a to 1e by the same output.

In this embodiment, the coupling 2 projects from the mount surface of the camera only when it is determined that the new AF lens (B) is attached to the camera (A).

In the embodiment, when the old AF lens (C) is attached, the terminal
Although it is stated that the motor drive signal is output from 1b to 1d, as is clear from the description of the embodiment, in detail, the motor drive signal is output from the terminals 1b and 1c, and the pulse output from the lens is input from the terminal 1d. It

(Effects of the Invention) As described in detail above, according to the present invention, even if different types of optical members are mounted, control can be performed according to the mounted optical members, which is convenient for the user. Specifically, an optical member (non-AF
When the lens is attached, the power supply operation to the non-AF lens is stopped, so that unnecessary power is not consumed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.
(A) is a camera, (B) is a new AF lens, (C) is an old AF lens, (D) is a conventional lens that is not an AF lens, and FIG. 2 is a flow chart for identifying the type of lens. [Explanation of symbols of main parts] 1a to 1e ... Terminal 2 ... Coupling 3 ... Switching circuit 4 ... Motor drive signal generation circuit 5 ... Photodetector 6 ... CPU 7 ... Motor

Claims (1)

(57) [Claims] 1. A first optical member comprising a lens element for focusing, the focus of which can be adjusted by a motor, and a lens element,
A detachable portion for selectively attaching and detaching a second optical member that does not perform focus adjustment by a motor, and an optical member that is provided in the vicinity of the attachable portion and is attached to the attachable portion when the optical member is attached. A terminal for performing communication, an identification unit for identifying the optical member attached to the attachment / detachment unit based on a communication operation via the terminal, a power supply unit for supplying power to the optical member, and the identification unit for identifying the optical member. When it is identified that the first optical member is mounted, the power feeding operation by the power feeding unit is permitted, and when it is identified that the second optical member is mounted by the identifying unit, A camera having a control unit for prohibiting the power supply operation by the power supply unit.