FR2658309A1 - ASSEMBLY FOR MOUNTING OPTICAL DEVICES. - Google Patents

Abstract

An assembly of mounts having mounts which are disposed on optical devices to be removably attached to each other and which have contact faces (15, 21a) which come into contact with each other when the optical devices are attached to each other by means of the fixtures, wherein at least one of the fixtures in combination has a mounting body (21) which is made of a synthetic resin and which is provided with a contact face (21a) and a metallic annular reinforcing member (22) for reinforcing the mounting body (21). Application to the mounting of interchangeable lenses on bodies of cameras.

Description

OPTICAL DEVICE MOUNTING ASSEMBLY

  The present invention relates to a mounting mechanism for mounting an optical device such as a camera body, an interchangeable lens, different converters, an intermediate ring, a

  diaphragm, or something similar.

  A bayonet mount is usually incorporated into such a mounting mechanism. The bayonet mount usually includes a male mount (e.g. a lens mount from a single lens reflex camera) and a female mount (e.g. a mount '' a body of a camera), equipped with a pair of optical devices to be fixed to each other The male and female assemblies are provided with a plurality of teeth which can be engaged with each other when the assemblies are introduced and turned with respect to each other, when the male and female assemblies are engaged, the contact faces of the opposite assemblies are brought into pressing contact with each other using

of a spring.

  The mounting element is usually made of metal to ensure that it is sufficiently

  resistant and can be machined precisely.

  However, since the mounting element has a complicated outline, it requires a large number of complex machining steps. In addition, the contact faces of the mounting elements must be subjected to an anti-seize surface treatment, to prevent the faces from being damaged due to sliding contact between the metal faces, or to provide gentle sliding when one of the mounting elements is rotated relative to the other In addition, in cases where the faces contacts carry electrical contacts, it is necessary to provide isolation means for the electrical contacts Consequently, mounting is one of the most expensive components of a camera In addition, adjustment during mounting and of the dismantling of the mounting elements deteriorates over time due to the wear of the metal surfaces, even if the surfaces are subjected to the surface treatment as mentioned above or to a treatment of surface lubrication. The first object of the present invention is to create an assembly which can be produced inexpensively and precisely and which has sufficient strength, wear resistance, high corrosion resistance.

and improved fit.

  The present invention provides for this purpose a set of assemblies having assemblies which are arranged on optical devices to be detachably fixed to each other and which have contact faces which come into contact with one another. other when the optical devices are fixed to each other by means of the assemblies, in which at least one of the assemblies comprises in combination a mounting body which is made of a synthetic resin and which is provided with a contact face and a mechanical annular reinforcing element

to strengthen the mounting body.

  Since it is easy to precisely manufacture a complicated shape in an injection mold using a

  synthetic resin, no precise machining is necessary.

  The reduction in resistance due to the synthetic resin can be compensated by the annular metallic reinforcing element No high precision of machining of the annular element is necessary More precisely, in the assembly assembly according to the present invention, the precision in the shape is ensured by the mounting body made of synthetic resin and the resistance is increased by the annular element of

metal reinforcement.

  The annular reinforcing element can be embedded in the mounting body made of synthetic resin or it can consist of a separate piece which can be mounted and fixed on the mounting body at the same time as the body

mounting.

  The annular reinforcing element can be used as an electrical conductor On the other hand, the mounting body made of synthetic resin can be used as an insulating element For this purpose, for example, the grounding element arranged on the contact face is brought into contact with the annular reinforcing element and the contact pin arranged on the contact face is not brought

  in contact with the annular reinforcing element.

  Preferably, the mounting body of synthetic resin is made of a technical plastic which can be injection molded, such as a polyphenylenesulfite or an anisotropic polymer. As a variant, it is also possible to produce the body of

  mounting in self-lubricating resin, in impregnated resin -

  oil, etc. The present invention can be applied to at least one of the mounting elements to be fixed to each other, in which case the other mounting element can be made of metal while retaining characteristics of

desired slip.

  According to another aspect of the present invention, there is provided a camera system comprising a camera body having a female mount and an interchangeable lens having a male mount which can engage in the female mount of the body. camera in which at least one of the male and female assemblies comprises a combination of a mounting body which is made of synthetic resin and which comes into contact with the other mounting and a metallic annular reinforcing element which does not come in contact with the other mounting element. Preferably the male mounting of the lens

interchangeable is made of metal.

  This description relates to the object contained

  in Japanese patent application Born 2-33020 (filed on

February 14, 1990).

  The characteristics and advantages of the invention

  will emerge from the description which follows

  by way of example with reference to the accompanying drawings, in which: FIG. 1 is a front elevation view of a camera comprising a camera body to which a mounting is fixed according to an aspect of the present invention; Figures 2, 3 and 4 are sectional views along lines II-II, III-III, IV-IV of Figure 1, respectively; Figure 5 is a plan view of a single elastic ring used in the present invention; Figures 6, 7 and 8 are sectional views corresponding, respectively, to Figures 2, 3 and 4, according to another aspect of the present invention; and Figure 9 is a perspective view of an interchangeable lens which can be mounted on a body mount

  a camera body according to the present invention.

  The embodiments shown are applied to a body mount 20 of a camera body 11 to which a lens mount 14 of an interchangeable lens 12 is detachably attached. In the embodiments shown, the mount of is

made of metal.

  The lens mount 14 which is shown generally in Figure 9 has a contact face, an annular groove 16 located behind the contact face 15, and predetermined shapes of prongs (protrusions) 17 which are spaced apart. '' from each other at a predetermined distance and which protrude in the radial direction

and outward.

  In the first embodiment shown in Figures 1 to 5, the body mounting 20 has a mounting body 21 made of synthetic resin, an annular reinforcing element (metallic annular element) 22 and a

  elastically deformable annular element 23.

  The mounting body 21 has a contact face 21 a which comes into contact with the contact face 15 of the interchangeable lens 12 Recesses 21 c through which the radial projections 17 of the interchangeable lens 12 can pass, and radial claws (projections) 21 d which are adjacent to the recesses 21 c and which are placed on the front faces of the projections 17 when the interchangeable lens 12 is fixed The mounting body 21 also has insertion holes for fixing screws 24, AF (autofocus) junction, grounding pin 26, contact pins

27 and a locking pin 28.

  The components of the mounting body 21 can be produced precisely on the mounting body by injection molding of a synthetic resin. A synthetic resin in which the mounting body 21 is made can preferably be a technical plastic which can be used in an injection molding process such as a polyphenylene sulfite (PPS), an anisotropic polymer or a self-lubricating resin or a

resin impregnated with oil.

  The annular reinforcement element 22 is inserted and molded in the mounting body 21 The annular reinforcement element 22 has insertion holes for the fixing screws 24, the AF junction 25, the earthing lug 26, the contact pin 27 and the locking pin 28, in a similar manner, to the mounting body 21 The insertion hole 22 has annular reinforcing element 22 in which the contact pin 27 is loosely inserted with a clearance between them is covered so that the contact pin 27 is isolated from the insertion hole 22 a On the other hand, the grounding pin 26 is brought

  in contact with the annular reinforcing element 22.

  The elastically deformable annular member (annular spring member) 23 has an annular body 23 a and spring portions 23 b which extend from the annular body 23 a and which are bent into a predetermined shape to match the teeth 21 d from

  mounting body 21 as shown in FIG. 5.

  Each of the spring parts 23 b has a raised part projecting parallel to the direction of the optical axis to resiliently press the teeth 17 of the interchangeable lens 12 in the rearward direction to bring the contact face 21 by this means. a of the mounting body 21 in close contact with the contact face 15 of the

lens mount 14.

  The annular body 23a of the annular spring element 23 is superimposed on the inner peripheral surface part of the mounting body 21 and it is fixed to the camera body 30 More precisely, the mounting body 21 in which the annular reinforcing element 22 is embedded and the spring element 23 are fixed to the camera body 30 by the fixing screws 24 The AF junction 25, the grounding lug 26, l contact pin 27 and locking pin 28, etc. are introduced into the respective insertion holes The heads of the fixing screws 24 are in direct contact with the annular reinforcing element 22, so that the mounting body 21 is prevented from being damaged at the points of contact with the screws

mounting 24.

  The earthing pin 26 and the contact pin 27 are returned by means of a spring 31 in a direction such that they protrude from the contact face 21 a Since the insertion hole 22 a of the annular reinforcing element 22 does not come into contact with the contact lug 27 as mentioned above, the mounting element 20 does not require a special insulation means for the lug contact 27 The camera body 30 is provided with an insulation means for the contact pin

27.

  On the interchangeable lens 12 are disposed a grounding pin 18 and a contact pin 19 which are connected to the grounding pin 26 and to the pin

  27 of the camera body 11, respectively.

  The earthing pin 18 and the contact pin 19 are isolated from the lens mounting 14 by respective insulating elements 18 a and 19 a and they are electrically connected to a control circuit 40 on the side of the objective The earthing pin 26 and the contact pin 27 are connected to a control circuit 50 on the body side

camera.

  In the mounting member 20 constructed as indicated above, according to the present invention, the mounting body having a complex contour can be easily and inexpensively injection molded. In addition, the annular reinforcing member 22 has a simple shape, and therefore it can be inexpensively made of metal Therefore, as a whole, the manufacturing cost can be reduced remarkably, any

  guaranteeing the necessary robustness and precision.

  Since the contact face 21 a is made of synthetic resin, no noise occurs during the sliding contact of the contact faces 21 a and 15 In particular, since the technical plastic has a high mechanical resistance, that it is highly resistant corrosion, and highly resistant to wear, there is no variation in the friction characteristics in

  despite repeated assembly and disassembly.

  Figures 6 to 8 show a second embodiment of the present invention In this embodiment, the annular reinforcing element 22 of the first embodiment mentioned above in which it is embedded in the mounting body 21 is replaced by an attachment of the type of the annular reinforcing element 29 which is introduced into an annular groove (a recess) 21 b which is produced on the contact face 2 la of the mounting body 21 A The face of the annular element of reinforcement 29 is slightly set back from the contact face 21 a so as not to come into contact with the contact face of the objective 15 In the embodiment shown, the annular reinforcement element 29 is provided with insertion holes similar to those of the annular reinforcing element 22 The insertion holes for the contact pin 27 has the shape of a through hole 29 a into which the contact pin 27 is introduced in a manner re loose without coming into contact with it The annular reinforcing element 29 is inserted into the annular groove 21 b and fixed to the camera body 30 at the same time as the mounting body 21. The junction of AF 25 is suitable for transmitting, for example, a focusing drive force on the side of the interchangeable lens from the side of the camera body The locking pin 28 is introduced into a locking hole associated with the interchangeable lens 12 for locking and unlocking the assembly The locking pin 28 is biased in a direction such that it projects from the contact face 21 a and can be retracted from the latter against the return force by an assembly and disassembly operating lever 28 a (FIG. 1 a) The control circuits 40 and 50 on the lens side and on the side of the camera body are interconnected by the contact pins 27 and 19 and the pins d e to earth 26 and 18 to transmit the necessary information between

them, respectively.

  The embodiments shown mentioned above are applied to a mounting element which has a grounding lug 26 and a contact lug 27 on the contact face 21 a for signal transmission, the contact lug 27 can be easily isolated. However, the present invention can be advantageously applied to a mounting element which has no contact pin 27 and no contact pin.

the mass 26.

Claims (9)

  1 assembly assembly comprising: a pair of assemblies which are arranged on optical devices to be detachably fixed to each other and which have contact faces (15, 21 a)) which come into contact with each other when the optical devices are fixed to each other by means of the arrangements, characterized in that at least one of the arrangements comprises in combination a mounting body (21) which is made of a synthetic resin and which is provided with a contact face (21a) and with a metallic annular element of   reinforcement (22) to reinforce the mounting body (21).   2 assembly assembly according to claim 1, characterized in that said metallic annular element (22) is embedded in the mounting body (21) of synthetic resin. 3 assembly of assemblies according to claim 2, characterized in that said one of the assemblies is fixed to the   optical device associated by fixing screws (24).   4 assembly assembly according to claim 3, characterized in that said metallic annular element (22) comes directly into contact with the heads of the screws associated fastening (24).   5 assembly assembly according to claim 1, characterized in that the metallic annular element (22) is made of a separate part of the mounting body (21) of synthetic resin and is fixed to the associated optical device at the same time as the mounting body (21) by fixing screw (24).   6 assembly of assemblies according to claim 1, characterized in that said one of the assemblies is equipped with a contact lug (27) facing the contact face (21a) thereof and not coming into contact with   the metallic annular reinforcing element (22).   7 assembly assembly according to claim 1, characterized in that the other assembly (14) is made of metal. 8 assembly assembly according to claim 1, characterized in that the mounting body (21) of synthetic resin is made of a material selected from a group comprising polyphenylenesulfites, anisotropic polymers, self-lubricating resins, and resins impregnated with oil.   9 assembly assembly according to claim 1, characterized in that one of said optical devices is a camera body (11) and the other is a interchangeable lens (12).