JPH0440195Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention stores lens information such as maximum aperture and focal length in an integrated circuit (hereinafter referred to as IC) and transmits this information to the camera body. The present invention relates to a protection device for an IC in an interchangeable lens having a contact point that protects the IC.

[Prior art] In recent years, lens information such as maximum aperture and focal length has become
Interchangeable lenses have been proposed that store information in an IC and transmit this information to the camera body. this
Since ICs are easily destroyed by static electricity, countermeasures have been taken either on the electric circuit or inside the IC, but the effects are not perfect. In particular, interchangeable lenses with built-in ICs have contacts for transmitting information to the camera body, so they are susceptible to electric shock through these terminals, which can destroy the IC. To solve this problem, a camera has been proposed that is equipped with a cover that automatically covers the contacts when the interchangeable lens is removed from the camera body. (Refer to Japanese Utility Model Application No. 57-79831) [Problems to be solved by the invention] In the device that covers the contacts with the cover described above, the mechanism for putting in and taking out the cover is complicated and requires a large space. There was a problem. The present invention was developed in view of these problems, and aims to provide an interchangeable lens having an IC protection device that has a simple configuration and does not require a large space.

[Means and effects for solving the problems] The configuration of the present invention will be explained using FIG. 1. A terminal 1a of a lens information storage IC 1, which is provided in the interchangeable lens, stores lens information, and processes and transmits signals to the camera body, is connected to a signal input/output contact 2. The terminal 1a is connected to ground 4 via an IC protection switching member 3, and a detachment detection member 5 detects that the interchangeable lens barrel is detached from the camera body. do.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 2 to 4. FIG. 2 shows the appearance of an interchangeable lens 6 according to this invention, in which a plurality of signal input/output contacts 7 are provided on a lens mount 8 of the interchangeable lens 6. As shown in FIG. 3, this signal input/output contact 7 is buried in a through hole provided in a contact base 9 made of an insulating material, and is conductive on a substrate 12 on which the IC 1 is installed. It is connected to the pattern 12a by soldering or the like. The lens mount 8 is made of a conductive material such as metal, and when attached to the camera body, it is at the same ground level as the electrical circuit of the camera body. A fan-shaped earth plate 11 (see FIG. 4) is fixed to a gap provided inside the lens mount 8 with screws 11a. This ground plate 11 is made of a conductive elastic material, and its free end 11b is adapted to come into elastic contact with the end surface of the contact 7. Further, an interchangeable lens detachment sensing pin 10 serving as a detachment detection member 5 is loosely inserted into a hole 8a of the lens mount 8. Above sensing pin 1
0 is appropriately fixed to a ground plate 11, and is adapted to protrude outward from the mount 8 due to the elastic force of this ground plate 11.

The operation of one embodiment of the present invention constructed as above will be explained. When the interchangeable lens 6 is attached to the camera body (not shown), the interchangeable lens detachment detection pin 10 is pressed by the camera side mount (not shown), and the ground plate 11 is connected to the signal input/output contact 7.
Since each signal input/output contact 7 is connected only to the IC 1, information can be transmitted to the camera body. Next, interchangeable lens 6
When the lens is detached from the camera body, the interchangeable lens detachment sensing pin 10 is pressed by the elasticity of the ground plate 11 and protrudes from the lens mount 12.
contacts the signal input/output contact 7, and each terminal of IC1 becomes ground level. As a result, IC1
Even if static electricity is applied to the terminals, the IC will not be destroyed because they are at ground level.

Next, another embodiment of the present invention will be explained based on FIG.

Contact stand 15 provided on lens mount 8
is provided with a large-diameter hole 15a and a small-diameter hole 15b communicating with the large-diameter hole 15a. This large diameter hole 15a,
A signal input/output contact 16 made of a conductive material and having a T-shaped cross section and also serving as a detachment detection member is loosely inserted into the small diameter hole 15b, and the conductive spring 1
7 urges the contact 16 to protrude from the small diameter hole 15b. Additionally, this spring 17 is connected to a flexible printed circuit board (hereinafter referred to as FPC) 18.
is in contact with the electrode 18a. On the other hand, this FPC1
8 is provided with an FPC presser 19 for pressing and holding the FPC 18 against the contact base 15. Further, an electrode 20 is provided on the boundary surface 15c between the large diameter hole 15a and the small diameter hole 15b, and this electrode 20 is connected to the earth level 4.

The operation of another embodiment of the present invention constructed as described above will be explained.

When the interchangeable lens 6 is attached to the camera body, the signal input/output contacts 16 are pressed by the camera-side mount and buried in the contact base 15, and are not in contact with the electrodes 20. Therefore, the contact 16 is connected only to the terminal of the IC 1 via the spring 17 and the electrode 18a of the FPC 18. In this state, signals can be transmitted to the camera body. When the interchangeable lens is removed from this state, the signal input/output contacts 16 protrude from the contact base 15 and come into contact with the electrodes 20. Therefore, terminal 1' of IC1 is at ground level, and the IC is not destroyed by static electricity.

As described above, in this other embodiment, the signal input/output contact 16 serves both as the detachment detection member 5 and the switching member 3, and the number of parts can be reduced. In this other embodiment, the electrode 20 is provided inside the contact base 15, but as shown in FIG. 6, an electrode 21 may also be provided to prevent the signal input/output contact 16 from coming off. In this case, when the interchangeable lens 6 is attached to the camera body, if the contact 16 is tilted due to play between the contact base 15 and the contact 16, it contacts the electrode 21 and generates an erroneous signal. In order to prevent this, it is preferable to provide an insulating plate 22 on the outside of the electrode 21, which has a hole smaller in diameter than the hole 21a of the electrode 21 that guides the contact 16. Due to this, contact 16
Even if it is tilted, it will just touch the insulating plate 22,
There is no risk of false signals.

[Effects of the invention] As described above, the present invention provides a detachment detection member that detects when the interchangeable lens is detached from the camera body, thereby making the switching member conductive and bringing the terminal of the integrated circuit to the ground level when detached. As a result, even if static electricity is applied from the signal input/output contacts, the IC will not be destroyed. In addition, the present invention has the advantage of being extremely simple and requiring only a small space, since it is sufficient to simply add a switching member for setting the IC terminal to the ground level and a detachment detecting member.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram showing the present invention, Fig. 2 is an external perspective view of an interchangeable lens showing an embodiment of the present invention, and Fig. 3 is a conceptual diagram showing the present invention.
The figure is a sectional view in the optical axis direction near the lens mount of the interchangeable lens, FIG. 4 is a sectional view taken along line A-A in FIG. 3, and FIG. 5 is a lens mount of an interchangeable lens showing another embodiment of the present invention. FIG. 6 is a sectional view of the vicinity of the lens mount of an interchangeable lens showing still another embodiment of the present invention in the optical axis direction. 1... integrated circuit, 2, 7, 16... contact, 5,
10... Disengagement detection member, 3, 11... Switching member.

Claims (1)

[Scope of Claim for Utility Model Registration] An interchangeable lens that has an integrated circuit that stores lens information and a contact that is connected to the integrated circuit and that transmits the information to the camera body, wherein the interchangeable lens is detached from the camera body. a detachment detection member that detects that the integrated circuit is disconnected; a switching member that is provided between the terminal of the integrated circuit and the contact and sets the terminal of the integrated circuit to a ground level when the detection member detects detachment; An interchangeable lens having an integrated circuit protection device.