Rotary encoder

Abstract: A rotary encoder including a code member having an annular plate-shaped portion and a plurality of tongues formed as a result of bending from the plate-shaped portion. The code member is formed of a metallic plate. The code member is mounted to the rotary member so that the tongues are positioned at the circumferential surface of the rotary member, and the plate-shaped portion is positioned at an end surface of the rotary member. This makes it possible to provide a small, low-cost rotary encoder.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary encoder used in, for example, computer terminal devices, portable communication devices, or sound devices. 2. Description of the Related Art The structure of a conventional rotary encoder will be described with reference to Figs. 51 to 55. An insulating base 51 molded out of synthetic resin includes a base portion 51b having a hole 51a in the center portion thereof, a pair of arms 51c which extend at right angles from both ends of the base portion 51b, and supporting portions 51d which are provided at ends of the arms 51c and which have holes formed by cutting away portions thereof. Contactors 52 formed of metallic plates have contact portions 52a and terminal portions 52b. Similarly, a common contactor 53 formed of a metallic plate has a contact portion 53a and a terminal portion 53b. The contactors 52 and the common contactor 53 disposed in a row are embedded into and mounted to the base portion 51b. The contact portions 52a and the contact portion 53a are positioned at the hole 51a. The terminals 52b and the terminal 53b protrude outward from the base portion 51b. A resilient plate 54 formed of a metallic plate disposed in a row with the contactors 52 and the common contactor 53 is mounted to the base portion 51b. A cylindrical rotary member 55 comprises a cylindrical portion 56 molded out of synthetic resin, and a code member 57 which is provided at the outer circumferential surface of the cylindrical portion 56 and which is formed of an electrically conductive material. The code member 57 is formed by molding electrically conductive resin twice. A common pattern 57a, a comb-like code pattern 57b, and a clicking uneven portion 56a are formed at the outer circumferential surface of the cylindrical portion 56 so as to be disposed in a row in the rotational axial direction thereof. Shafts 56b are provided at both end surfaces of the cylindrical portion 56. A noncircular hole 56c is formed in the center portion of the cylindrical portion 56. In the rotary member 55, the shafts 56b are snappingly stopped by the supporting portions 51d of the pair of arms 51c in order to be rotatably mounted to the insulating base 51. When the rotary member 55 has been mounted, the contact portion 53a of the common contactor 53 is in contact with the common pattern 57a, the contact portions 52a of the contactors 52 are in contact with the code pattern 57b, and the resilient plate 54 is in resilient contact with the uneven portion 56a. A dome-shaped cover 58 is mounted to the insulating base 51 so as to cover the rotary member 55, whereby a body E2 of the encoder is constructed. As shown in Fig. 53, the body E2 of the encoder is such that the bottom surface of the insulating base 51 is placed on a printed board P2. The terminal portions 52b of the contactors 52 and the terminal portion 53b of the common contactor 53 are inserted through a hole in the printed board P2 in order to solder the terminal portions 52b and the terminal portion 53b onto a wiring pattern (not shown). This results in the structure where the body E2 of the encoder is mounted to the printed board P2. The operation of the rotary encoder having the above-described structure will be described. When an actuating shaft (not shown) inserted in the hole 56c of the rotary member 55 is rotated from the outside, the rotary member 55 is rotated. When the rotary member 55 is rotated, the code member 57 is also rotated. This causes the common contact 53 to always contact the common pattern 57a, and the contactors 52 to contact with and separate from the code pattern 57b, so that a pulse signal is generated between the common contactor 53 and the contactors 52. By the rotation of the uneven portion 56a resulting from the rotation of the rotary member 55, when the resilient plate 54 engages and disengages the uneven portion 56a, the rotary member 55 clicks. In this way, the rotary encoder is operated. However, since the conventional rotary encoder is formed by molding the code member 57 out of electrically conductive resin, it is troublesome to produce the conventional rotary encoder, the productivity of conventional rotary encoders is low, and costs are high. In addition, since the common pattern 57a, the code pattern 57b, and the clicking uneven portion 56a are disposed in a row along the outer circumferential surface of the rotary member 55, the conventional rotary encoder becomes large in the rotation axial direction of the rotary member. A fuller description of the conventional rotary encoder as hereinbefore discussed can be found in JP-A-11039998. Further details in relation to rotary switches in general can be found in United States Patent No 5,072,078 and in British Patent No 1 537 028. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a small, low-cost rotary encoder. According to an aspect of the present invention there is provided a rotary encoder comprising: a rotary member which is formed of an insulating material and is of a columnar, cylindrical or truncated conical shape, a code member mounted to the rotary member and formed of a metallic plate; and a plurality of contactors which contact the code member; characterised in that the code member comprises an annular plate-shaped portion and a plurality of tongues formed as a result of bending from the plate-shaped portion; wherein the plate-shaped portion is disposed in a direction perpendicular to a rotational axial direction of the rotary member; and wherein the tongues are disposed so as to be exposed at a circumferential surface side of the rotary member. Accordingly, since the code member comprising an annular plate-shaped portion and a plurality of tongues formed as a result of bending from the plate-shaped portion are formed of a metallic plate, it is possible to provide a low-cost rotary encoder which can be easily produced with high productivity compared to the conventional case where a molding operation is carried out using electrically conductive resin. In addition, since the plate-shaped portion is disposed in a direction perpendicular to the rotational axial direction of the rotary member, and the tongues are disposed so as to be exposed at the circumferential surface side of the rotary member, a proper space factor for the plate-shaped portion is obtained with respect to the rotational axial direction, so that a small rotary encoder can be provided. The tongues of the code member may be formed as a result of bending from an outer peripheral portion of the plate-shaped portion. Accordingly, this structure is effective when tongues need to be made long. The tongues of the code member may be formed as a result of bending from an inner peripheral portion of the plate-shaped portion. Accordingly, material from the metallic plate can be properly taken away, making it possible to provide a small, low-cost rotary encoder. When the tongues of the code member are formed as a result of bending from an outer peripheral portion of the plate-shaped portion, the tongues of the code member may be disposed at an outer circumferential surface side of the rotary member. When the tongues of the code members are formed as a result of bending from an inner peripheral portion of the plate-shaped portion, the tongues of the code member may be disposed at an outer circumferential surface side of the rotary member. Accordingly, the contactors can be freely disposed, making it possible to provide a rotary encoder adapted to various forms. When the tongues of the code member are formed as a result of bending from an outer peripheral portion of the plate-shaped portion, the rotary member may have a cylindrical shape, and the tongues of the code member may be disposed at an inner circumferential surface side of the rotary member. When the tongues of the code member are formed as a result of bending from an inner peripheral portion of the plate-shaped portion, the rotary member may have a cylindrical shape, and the tongues of the code member may be disposed at an inner circumferential surface side of the rotary member. Accordingly, the code member can be made small, making it possible to provide a small rotary encoder. When a rotary encoder comprises a rotary member, a code member, and a plurality of contactors, the code member may be embedded into the rotary member in order to be mounted to the rotary member. Accordingly, the producing process can be simplified, and good productivity is achieved, making it possible to provide a low-cost rotary encoder. When a rotary member comprises a rotary member, a code member, and a plurality of contactors, the tongues of the code member may be fitted into a groove formed in the circumferential surface side of the rotary member in order to mount the code member to the rotary member. Accordingly, it is possible to easily adapt to various forms of the code member, so that an adaptable rotary encoder can be provided. When the code member is embedded into the rotary member in order to be mounted to the rotary member, the plate-shaped portion may be disposed at an end surface side of the rotary member which extends perpendicular to the rotational axial direction of the rotary member. Accordingly, during the producing process, the plate-shaped portion can be supported by a die, making it possible to provide a rotary encoder with good productivity. When a rotary member comprises a rotary member, a code member, and a plurality of contactors, the contactors may be brought into contact with the plate-shape portion and the tongues, the plate-shaped portion may be a common contact, and the tongues may be change-over contacts. Accordingly, the amount of space in the rotational axial direction can be made small, making it possible to provide a small rotary encoder. Preferably, the rotary encoder comprises a code pattern formed by the tongues at an external circumferential surface of the rotary member, wherein the plurality of contactors contact the code pattern; and a clicking uneven portion is formed at an end surface of the rotary member; and an engaging member adapted to engage and disengage with the uneven portion in order to form a click mechanism. Accordingly, since the code pattern is formed at the circumferential surface of the rotary member, and the clicking uneven portion is formed at one end surface of the rotary member to allow the engaging member to engage and disengage the uneven portion in order to construct a clock mechanism, the code pattern can be made long, and the length of the rotary member in the rotational axial direction can be made smaller than that of a rotary member of a conventional rotary encoder. Therefore, it is possible to provide a small rotary encoder. A common pattern which is electrically conductive with the code pattern may be formed at the other end surface of the rotary member which opposes the one end surface of the rotary member, and a common contactor may be-in contact with the common pattern. Accordingly, the space in the rotational axial direction at the common pattern becomes small, making the size in the rotational axial direction even smaller. Therefore, it is possible to provide a small rotary encoder. When a common pattern which is electrically conductive with the code pattern is formed at the other end surface of the rotary member which opposes the one end surface of the rotary member, and a common contactor is in contact with the common pattern, the plurality of contactors may be disposed opposite each other, with the circumferential surface of the rotary member being disposed therebetween, the engaging member may be disposed so as to oppose the one end surface of the rotary member, and the common contactor may be disposed so as to oppose the other end surface of the rotary member. Accordingly, they are not disposed in a row in the rotational axis direction with respect to each other, so that a proper space factor is obtained in the rotational axis direction. This makes it possible to provide a small rotary encoder. When the plurality of contactors are disposed opposite each other, with the circumferential surface of the rotary member being disposed therebetween, the engaging member is disposed so as to oppose the one end surface of the rotary member, and the common contactor is disposed so as to oppose the other end surface of the rotary member, the contactors and the common contactor may be mounted to an insulating base formed of an insulating material, and the contactors, the common contactor, and the engaging member may be provided so as to extend in the direction of the rotary member, with the insulating base as a reference surface. Accordingly, the reference of the contactors, the common contactor, and the engaging member in the height direction is the insulating base, so that the precision with which they are mounted relative to each other can be increased. Therefore, it is possible provide a highly precise rotary encoder. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front view of a rotary encoder in accordance with the present invention. Fig. 2 is a back view of the rotary encoder in accordance with the present invention. Fig. 3 is a top view of the rotary encoder in accordance with the present invention. Fig. 4 is a bottom view of the rotary encoder in accordance with the present invention. Fig. 5 is an exploded perspective view of the rotary encoder in accordance with the present invention. Fig. 6 is a sectional side view of the main portion of the rotary encoder in accordance with the present invention. Fig. 7 is a sectional front view of the main portion of the rotary encoder in accordance with the present invention. Fig. 8 is a perspective view of an insulating base and a rotary member that are assembled together in the rotary encoder in accordance with the present invention. Fig. 9 is a front view of a first example of an insulating base of the rotary encoder in accordance with the present invention. Fig. 10 is a side view of the first example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 11 is a bottom view of the first example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 12 shows the relationship between the first example of the insulating base and a contactor of the rotary encoder in accordance with the present invention. Fig. 13 illustrates a method of producing the insulating base of the rotary encoder in accordance with the present invention. Fig. 14 is a front view of a second example of an insulating base of the rotary encoder in accordance with the present invention. Fig. 15 is a side view of the second example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 16 is a bottom view of the second example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 17 shows the relationship between the second example of the insulating base and a contactor of the rotary encoder in accordance with the present invention. Fig. 18 is a front view of a first example of a rotary member of the rotary encoder in accordance with the present invention. Fig. 19 is a side view of the first example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 20 is a back view of the first example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 21 is a sectional side view of the first example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 22 illustrates a method of producing the first example of the rotary member and a code member of the rotary encoder in accordance with the present invention. Fig. 23 illustrates the method of producing the first example of the rotary member and the code member of the rotary encoder in accordance with the present invention. Fig. 24 is a sectional view taken along line XXIV-XXIV in Fig. 23. Fig. 25 illustrates the method of producing the first example of the rotary member and the code member of the rotary encoder in accordance with the present invention. Fig. 26 is a perspective view of the code member of the rotary encoder in accordance with the present invention. Fig. 27 is a front view of a second example of a rotary member of the rotary encoder in accordance with the present invention. Fig. 28 is a side view of the second example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 29 is a back view of the second example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 30 is a sectional side view of the second example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 31 is a perspective view showing a method of mounting the second example of the rotary member and a code member of the rotary encoder in accordance with the present invention. Fig. 32 is a front view showing a state in which the second example of the rotary member and the code member are assembled together in the rotary encoder in accordance with the present invention. Fig. 33 is a side view showing the state in which the second example of the rotary member and the code member are assembled together in the rotary encoder in accordance with the present invention. Fig. 34 is a front view of an engaging member of the rotary encoder in accordance with the present invention. Fig. 35 is a top view of the engaging member of the rotary encoder in accordance with the present invention. Fig. 36 is a bottom view of the engaging member of the rotary encoder in accordance with the present invention. Fig. 37 is a sectional view taken along line XXXVII-XXXVII in Fig. 34. Fig. 38 is a perspective view of a first example of a mounting plate of the rotary encoder in accordance with the present invention. Fig. 39 is a front view of the first example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 40 is a side view of the first example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 41 is a bottom view of the first example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 42 is a perspective view showing a state in which the first example of the mounting plate is mounted to the body of the rotary encoder in accordance with the present invention. Fig. 43 is a sectional view showing the main portion of the rotary encoder in accordance with the present invention where the first example of the mounting plate is mounted to the body of the rotary encoder. Fig. 44 is a perspective view showing the first example of the mounting plate mounted to the body of the rotary encoder in accordance with the present invention. Fig. 45 is a front view of a second example of a mounting plate of the rotary encoder in accordance with the present invention. Fig. 46 is a side view of the second example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 47 is a back view of the second example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 48 is a perspective view showing a state in which the second example of the mounting plate is mounted to the body of the rotary encoder in accordance with the present invention. Fig. 49 is a back view showing the state in which the second example of the mounting plate is mounted to the body of the rotary encoder in accordance with the present invention. Fig. 50 is a side view showing the state in which the second example of the mounting plate is mounted to the body of the rotary encoder in accordance with the present invention. Fig. 51 is a perspective view of a conventional rotary encoder. Fig. 52 is an exploded perspective view of the conventional rotary encoder. Fig. 53 is a sectional view showing a state in which a contactor resiliently presses a rotary member of the conventional rotary encoder. Fig. 54 is a sectional view showing a state in which a resilient plate resiliently presses the rotary member of the conventional rotary encoder. Fig. 55 is a perspective view of the rotary member of the conventional rotary encoder. DESCRIPTION OF THE PREFERRED EMBODIMENT A rotary encoder of the present invention will be described with reference to Figs. 1 to 50. Fig. 1 is a front view of a rotary encoder in accordance with the present invention. Fig. 2 is a back view of the rotary encoder in accordance with the present invention. Fig. 3 is a top view of the rotary encoder in accordance with the present invention. Fig. 4 is a bottom view of the rotary encoder in accordance with the present invention. Fig. 5 is an exploded perspective view of the rotary encoder in accordance with the present invention. Fig. 6 is a sectional side view of the main portion of the rotary encoder in accordance with the present invention. Fig. 7 is a sectional front view of the main portion of the rotary encoder in accordance with the present invention. Fig. 8 is a perspective view of an insulating base and a rotary member that are assembled together in the rotary encoder in accordance with the present invention. Fig. 9 is a front view of a first example of an insulating base of the rotary encoder in accordance with the present invention. Fig. 10 is a side view of the first example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 11 is a bottom view of the first example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 12 illustrates the relationship between a contactor and the first example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 13 illustrates a method of producing the insulating base of the rotary encoder in accordance with the present invention. Fig. 14 is a front view of a second example of an insulating base of the rotary encoder in accordance with the present invention. Fig. 15 is a side view of the second example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 16 is a bottom view of the second example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 17 illustrates the relationship between a contactor and the second example of the insulating base of the rotary encoder in accordance with the present invention. Fig. 18 is a front view of a first example of a rotary member of the rotary encoder in accordance with the present invention. Fig. 19 is a side view of the first example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 20 is a back view of the first example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 21 is a sectional side view of the first example of the rotary member of the rotary encoder in accordance with the present invention. Figs. 22 to 25 illustrate a method of producing a code member and the first example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 26 is a perspective view of the code member of the rotary encoder in accordance with the present invention. Fig. 27 is a front view of a second example of a rotary member of the rotary encoder in accordance with the present invention. Fig. 28 is a side view of the second example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 29 is a back view of the second example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 30 is a sectional side view of the second example of the rotary member of the rotary encoder in accordance with the present invention. Fig. 31 is a perspective view illustrating a method of mounting the second example of the rotary member and a code member of the rotary encoder in accordance with the present invention. Fig. 32 is a front view showing a state in which the second example of the rotary member and the code member are assembled together in the rotary encoder in accordance with the present invention. Fig. 33 is a side view showing the state in which the second example of the rotary member and the code member are assembled together in the rotary encoder in accordance with the present invention. Fig. 34 is a front view of an engaging member of the rotary encoder in accordance with the present invention. Fig. 35 is a top view of the engaging member of the rotary encoder in accordance with the present invention. Fig. 36 is a bottom view of the engaging member of the rotary encoder in accordance with the present invention. Fig. 37 is a sectional view taken along line XXXVII-XXXVII in Fig. 34. Fig. 38 is a perspective view of a first example of a mounting plate of the rotary encoder in accordance with the present invention. Fig. 39 is a front view of the first example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 40 is a side view of the first example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 41 is a bottom view of the first example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 42 is a perspective view showing a state in which the first example of the mounting plate is mounted to the body of the rotary encoder in accordance with the present invention. Fig. 43 is a sectional view showing the main portion of the rotary encoder in accordance with the present invention where the first example of the mounting plate is mounted to the body of the rotary encoder. Fig. 44 is a perspective view showing the first example of the mounting plate mounted to the body of the rotary encoder in accordance with the present invention. Fig. 45 is a front view of a second example of a mounting plate of the rotary encoder in accordance with the present invention. Fig. 46 is a side view of the second example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 47 is a back view of the second example of the mounting plate of the rotary encoder in accordance with the present invention. Fig. 48 is a perspective view showing a state in which the second example of the mounting plate is mounted to the body of the rotary encoder in accordance with the present invention. Fig. 49 is a back view showing the state in which the second example of the mounting plate is mounted to the body of the rotary encoder in accordance with the present invention. Fig. 50 is a side view showing the state in which the second example of the mounting plate is mounted to the body of the rotary encoder in accordance with the present invention. Referring to Figs. 1 to 50, the structure of the rotary encoder in accordance with the present invention will be described. As shown in Figs. 1 to 11, a first example of an insulating base 1 which is molded out of an insulating material comprises a rectangular main base portion 2, a side wall 3 provided vertically at right angles to the main base portion 2, and a pair of auxiliary base portions 5 connected at both sides of the main base portion 2 by thin portions 4. The main base portion 2 includes recesses 2a formed in both end surfaces thereof, a columnar protrusion 2b formed on the center of the front end surface thereof, and a pair of catching portions 2c having tapering bottom surfaces. The side wall 3 is provided vertically from the corners of the top surface of the main base portion 2. It includes a circular hole 3b which is formed at the center portion thereof and which has a flange 3a formed thereat, a pair of clearance holes 3c which extend from both sides of the hole 3b to the main base portion 2, a pair of top walls 3d which extend at right angles from the top portion thereof, a groove 3e formed between the pair of top walls 3d, stepped catching portions 3f formed on the top surfaces of the pair of top walls 3d, and protrusions 3g. The pair of auxiliary base portions 5 each comprise a protrusion 5a whose edge is rounded, and a small protruding linear portion 5b formed on the bottom surface of its corresponding protrusion 5a (see Fig. 11). As shown in Fig. 8, the insulating base 1 is formed into a rectangular shape by bending the thin portions 4 from the state shown in Fig. 5 and forcibly inserting the protrusions 5a of the auxiliary bases 5 into the corresponding recesses 2a in the main base portion 2. At this time, the protruding linear portions 5b of the auxiliary base portions 5 make it possible to easily and reliably forcibly insert the auxiliary base portions 5 into their corresponding recesses 2a. A plurality of first-example contactors 6 which are formed of metallic plates comprise contact portions 6a and terminal portions 6b. The plurality of contactors 6 are embedded into and mounted to the auxiliary base portions 5. The contact portions 6a protrude upward from the top surface of the insulating base 1. The terminal portions 6b protrude downward from the bottom portion of the insulating base 1. Flat ends of the terminal portions 6b are bend so as to be disposed at one end of the insulating base 1, that is, at about the location the side wall 3 in a parallel arrangement. A first-example common contactor 7 which is formed of metal comprises a pair of contact portions 7a and a terminal portion 7b. The common contactor 7 is mounted to the portion of the main base portion 2 close to the side wall 3. The contact portions 7a protrude upward from the top surface of the insulating base 1, and are disposed in the clearance holes 3c in the side wall 3. The terminal portion 7b protrude downward from the bottom surface of the insulating base 1. A flat end of the terminal portion 7b is bend so to be disposed at an end of the insulating base 1, that is, at about the location of the side wall 3 in a parallel arrangement. Thus, with reference to the plane of the side wall 3, the first-example common contactor 7 is mounted faced downward. In the first example, portions of the plurality of contactors 6 are embedded in the main base portion 2 and the auxiliary base portions 5 so as to bestride them. The thin portions 4 which connect the main base portion 2 and the auxiliary base portions 5 are formed on portions of their corresponding contactors 6. The thin portions 4 may be formed by using metallic plates which are different from those used to form the contactors 6 and which are embedded in the insulating base 1. In addition, the thin portions 4 which connect the main base portion 2 and the auxiliary base portions 5 may be formed of the insulating material used to form the insulating base 1. The method of producing the insulating base 1, the contactors 6, and the common contactor 7 will be described with reference to Fig. 13. A plurality of holes 22 are formed in a metallic plate 21 formed of a hoop material in order to form a top frame 21a and a bottom frame 21b. When the holes 22 are formed in the center of the metallic plate 21, a looped portion 21c used to form the contact portions 7a of the common contactor 7 is provided, and, at a portion of the looped portion 21c, the terminal portion 7b of the common contactor 7 is connected to the bottom frame 21b by a connecting portion 21d. On both sides of the looped portion 21c and the connecting portion 21d, the contact portions 6a of the contactors 6 are connected to the top frame 21a by corresponding connecting portions 21e. The terminal portions 6b of the contactors 6 are connected to the bottom frame 21b by corresponding connecting portions 21f. The contact portions 6a and the terminal portions 6b are connected by connectors 21g, which become the thin portions 4. In order to reliably hold the contact portions 6a during a molding operation, the bottom portions of the contact portions 6a are connected to the bottom frame 21b by connecting portions 21h. The metallic plate 21 having the above-described structure is clamped in a die (not shown). When resin is poured into the die, the main base portion 2, the side wall 3, and the auxiliary base portions 5 of the insulating base 1 are formed as shown by two short and one long dashed lines shown in Fig. 13. Then, cuts are formed along lines 23 in order to sever the contactors 6 and the common contactor 7 from portions of the metallic plate 21, and in order to sever the contact portions 7a of the common contactor 7 from portions of the looped portion 21c, whereby the pair of contact portions 7a are formed in a cantilever arrangement. As a result, as shown in Fig. 9, the insulating base 1 is produced. Figs. 14 to 17 illustrate a second example of an insulating base 1, a second example of contactors 6, and a second example of a common contactor 7. In the second examples, only the forms of terminal portions 6b of the contactors 6 and a terminal portion 7b of the common contactor 7 differ from those of the first examples. The other structural features are the same as those of the first examples so that corresponding parts are given the same reference numerals, and are not described below. In the second examples, the terminal portions 6b and 7b protrude from the bottom side of the insulating base 1, and have their ends bent into an L shape. As shown particularly from Figs. 18 to 21, a first example of a rotary member 8 molded out of an insulating material comprises a shaft 8a formed at one end thereof, a holding portion 8b which is formed so as to be connected to the shaft 8a and which has a larger diameter than the shaft 8a, a clicking uneven portion 8d provided at an end surface 8c which extends perpendicular to the rotational axial direction at one side of the holding portion 8b, an end surface 8e disposed between the shaft 8a and the holding portion 8b and extending perpendicular to the rotational axial direction at the other side of the holding portion 8b, a noncircular, hexagonal hole 8f formed in the center of the rotary member 8, and a stopper 8g formed at an outer peripheral end of the shaft 8a. As shown particularly in Fig. 26, a first example of a code member 9 formed of a metallic plate comprises an annular, plate-shaped portion 9a which forms a common pattern, and a plurality of tongues 9b which are formed by bending from the inner periphery of the plate-shaped portion 9a and which form a code pattern. The code member 9 is embedded into and mounted to the rotary member 8. The annular, plate-shaped portion 9a which forms a common pattern is positioned at the end surface 8e. The tongues 9b which form a code pattern are exposed at the outer circumferential surface of the holding portion 8b. A method of producing the rotary member 8 and the code member 9 will be described with reference to Figs. 22 to 26. As shown in Fig. 22, a comb-like hole 26 is formed in the center of a hoop-shaped metallic plate 25 in order to form the tongues 9b. Ends of the tongues 9d have shapes formed by chamfering so that they can be made long. Then, as shown in Figs. 23 and 24, holes 27 are formed at locations bordering an imaginary cross in order to form a frame 25a, to form the plate-shaped portion 9a connected to the frame 25a by a connecting portion 25b, and to bend the tongues 9b from the plate-shaped portion 9a. Then, as shown in Fig. 25, the plate-shaped portion 9a is clamped between two dies 28 and 29. While the tongues 9b are held in grooves 29a in the die 29, resin is poured into hollows 30 formed in the two dies 28 and 29 in order to form the rotary member 8. After the formation of the rotary member 8, as shown in Fig. 23, when cuts are formed along lines 31, the code member 9 is embedded in the rotary member 8 as shown in Fig. 26, whereby the production of the rotary member 8 and the code member 9 is completed. In the step shown in Fig. 25, the grooves 29a in the die 29 are slightly smaller in dimension than the tongues 9b. The entrance-side openings of the grooves 29a are formed so that they are wider in order to accommodate the tongues 9b in the grooves 29a so that no gaps are formed therebetween. Since resin is poured into the grooves 29a while the tongues 9b are accommodated in the groove 29a with no gaps therebetween, no resin film is formed at the outer surfaces of the tongues 9b. Some recesses of the clicking uneven portion 8d are formed where the die 29 holds the tongues 9b. Figs. 27 to 33 illustrate a second example of a rotary member 8 and a second example of a code member 9. In the second examples, the code member 9 is fitted and mounted to the rotary member 8. In addition to the structural features of the first example, the rotary member 8 comprises a plurality of grooves 8h in the rotational axial direction in the outer circumferential surface of a holding portion 8b. The other structural features are the same, so that corresponding parts are given the same reference numerals, and are not described below. As shown in Fig. 31, the code member 9 comprises an annular, plate-shaped portion 9a which forms a common pattern, and tongues 9b which are formed by bending from the plate-shaped portion 9a and which form a code pattern. The plate-shaped portion 9a and the tongues 9b are previously formed. As shown in Fig. 31, while the code member 9 is disposed at an end-surface-8e side of the rotary member 8, chamfered portions of ends of the tongues 9b are used as guides to forcibly insert and fit the tongues 9b into the grooves 8h. When this is done, as shown in Figs. 32 and 33, the plate-shaped portion 9a is disposed at the end surface 8e, and, with the tongues 9b being exposed at the outer circumferential surface of the holding portion 8b, the code member 9 is mounted to the rotary member 8. In the first- and second-example rotary members 8 and the first- and second-example code members 9, the shafts 8a of the first- and second-example rotary members 8 are inserted into the corresponding holes 3b of the side walls 3 so as to be rotatably held thereby. When the first-example rotary member 8 and the second-example rotary member 8 are mounted to their corresponding insulating bases 1, the stopper portions 8g are protrude from their corresponding holes 3b so as to prevent the first- and second-example rotary members 8 from getting dislodged. In addition, the pairs of contact portions 7a of the first- and second-example common contactors 7 are placed so as to oppose their corresponding end surfaces 8e and so as to be in contact with their corresponding plate-shaped portions 9a used to form common patterns of the code members 9. When the first- and second-example rotary members 8 are mounted to their corresponding insulating bases 1, the plurality of contactors 6 are disposed at opposite sides with respect to each other, with the circumferential surfaces of the corresponding rotary members 8 being disposed therebetween. In addition, they are disposed so as to come into contact with and separate from the tongues 9b which form code patterns of the corresponding code members 9. Further, as shown in Figs. 12 and 17, the contact portions 6a which extend from their corresponding insulating bases 1 resiliently contact their corresponding first- and second-example rotary members 8 at locations beyond the rotational centers of the first- and second-example rotary members 8. In the first and second examples, the pairs of contact portions 6a contact the corresponding code patterns with corresponding phase differences. Although the first- and second-example rotary members 8 are described as being cylindrical in shape, they may have columnar or truncated conical shapes. In the first and second examples, since the code members 9 have their tongues 9b formed by bending from the inner peripheral portions of their corresponding plate-shaped portions 9a, the corresponding connecting portions 25b can be disposed at any outer peripheral location thereof, so that a continuous series of processing operations using hoop materials can be carried out even if the gaps between the tongues 9b are made narrow. However, the tongues 9b may be formed by bending from the outer peripheral portions of the corresponding plate-shaped portions 9a. Although the tongues 9b of the first- and second-example code members 9 are formed at the outer circumferential surfaces of their corresponding cylindrical rotary members 8, the tongues 9b may be formed at the inner circumferential surfaces of the corresponding cylindrical rotary members 8 so that they contact the contact portions 6a of the corresponding contactors 6. Although, metallic plates are used to form the first- and second-example code members 9, the code patterns and the common patterns may be formed by plating or using electrically conductive powder of turned metallic materials. As shown particularly in Figs. 34 to 37, an engaging member 10 formed of a metallic plate comprises a rectangular plate-shaped base portion 10a, an engaging portion 10b which is bent into a C shape at the center portion of the base portion 10a and which has a protruding end, a circular hole 10c formed in the bottom portion of the base portion 10a, a pair of side plates 10d which are formed by bending from both sides of the base portion 10a, cut-and-raised portions 10e formed at both side plates 10d, a T-shaped top side plate 10g which is formed by bending from the top side of the base portion 10a and which has a stopper portion 10f at an end thereof, and a C-shaped bottom side plate 10j which is formed by bending from the bottom side of the base portion 10a and which has a rectangular hole 10h formed in the center thereof. The engaging portion 10b of the engaging member 10 is aligned with the insulating base 1 so as to oppose the end surface 8c of the rotary member 8 having the uneven portion 8d formed thereat. Then, the protrusion 2b is inserted into the hole 10c. Thereafter, the top side plate 10g is positioned on and pushed into the top wall 3d. After pushing the top side plate 10g into the top wall 3d, the engaging portion 10f is caught by the catching portion 3f, and the top plate 10g is positioned in the groove 3e in order to mount the top side plate 10g to the side wall 3. At the same time that the top side plate 10g is mounted, the bottom side plate 10j is positioned at and pushed onto the bottom surface of the main base portion 2. After pushing the bottom side plate 10j into the main base portion 2, the catching portion 2c is positioned at the hole 10h in order to catch the bottom side plate 10j by the catching portion 2c, whereby the bottom side plate 10j is mounted to the main base portion 2. In this way, the engaging member 10 is mounted at the top and bottom portions of the rotary member 8, and the side plates 10d are disposed at the left and right portions of the rotary member 8. When the engaging member 10 is mounted, the protruding portion of the engaging portion 10b is engageably and disengageably mounted to the uneven portion 8d at the end surface 8c of the rotary member 8 in order to form a clicking mechanism. The engaging member 10, the first- and second-example contactors 6, and the first- and second-example common contactors 7 extend in the direction of the first- and second-example rotary members 8, with the first- and second-example insulating bases 1 as reference surfaces. Such a structure is used to form a body E1 of the encoder. As shown in Figs. 38 to 44, a first example of a mounting plate 11 formed of a solderable metallic plate comprises a flat portion 11c having a large circular hole 11a formed in the center thereof and a small hole lib formed in the lower portion thereof, a pair of arms lid formed by bending from both sides of the flat portion 11c so as to oppose each other, rectangular holes 11e formed in the centers of the arms 11d, and mounting portions 11f formed by bending from ends of the corresponding arms 11d. As shown in Figs. 42 to 44, the mounting plate 11 is positioned at the engaging-member-10-side of the body E1 of the encoder in order to insert the protrusion 2b of the first example of the insulating base 1 into the small hole 11b. Then, the arms lid are disposed on and pushed onto the side plates 10d of the engaging member 10. The cut-and-raised portions 10e are positioned at the corresponding holes lie in order to catch the arms lid by the cut-and-raised portions 10e. This causes the mounting plate 11 to be snappingly stopped by the engaging member 10, whereby the mounting plate 11 is mounted to the engaging member 10. As shown in Fig. 43, when the mounting plate 11 is mounted, the flat portion 11c is placed upon an outer side of the plate-shaped base portion 10a of the engaging member 10. In addition, the arms 11d are mounted to the side plates 10d of the engaging member 10, at the left and right horizontal portions of the rotary member 8. Further, the bottom surfaces of the mounting portions 11f which are formed by bending from ends of the arms 11d extending in the rotational axial direction of the rotary member 8 are positioned at one end of the insulating base 1, that is, at about the same location as the side wall 3 in a parallel arrangement. As shown in Fig. 43, side-wall-3-side of the body E1 of the encoder in which the mounting plate 11 is mounted is placed on a printed board P1. At this time, the protrusions 3g are inserted into holes 13 in the printed board P1 in order to position the body E1 of the encoder, and the terminals 6b of the contactors 6, the terminal 7b of the common contactor 7, and the mounting portion 11f of the mounting plate 11 are disposed on a wiring pattern (not shown) formed on the top surface of the printed board P1. The contactors 6, the common contactor 7, and the mounting plate 11 having the above-described structures are mounted to the surface of the wiring pattern by cream soldering in order to be mounted to the printed board P1. This causes the body E1 of the encoder to be mounted to the printed board P1 in a direction perpendicular to the rotational axial direction of the rotary member 8, so that the body E1 of the encoder is mounted to the printed board P1 in a laid down state. The operation of the rotary encoder having the above-described structure will now be described. An operating member (not shown) is made to engage the hole 8f in the rotary member 8 as a result of passing it through the engaging member 10 and the hole 11a in the mounting plate 11, or the operating member is made to engage the hole 8f in the rotary member 8 as a result of passing it through a hole (not shown) in the printed board P1. Thereafter, when the operating member is rotated, the rotary member 8 and the code member 9 rotate with the shaft 8a as a support. The uneven portion 8d of the rotary member 8 is made to engage and disengage the engaging portion 11b to perform a clicking operation. In addition, the tongues 9b are made to contact with and separate from the contactors 6, and the common contactor 7 is made to always contact the plate-shaped portion 9a, so that a two-phase pulse signal is generated between the contactors 6 and the common contactor 7. Figs. 45 to 50 illustrate a second example of a mounting plate 12. The second example of the mounting plate 12 is formed of a solderable metallic plate, and comprises a flat portion 12c having a large circular hole 12a formed in the center portion thereof and a small hole 12b formed in the lower portion thereof, a pair of arms 12d formed by bending from both sides of the flat portion 12c so as to oppose each other, rectangular holes 12e formed in the center portions of the arms 12d, mounting portions 12f bend from side end portions of the arms 12d, and protrusions 12g formed adjacent to the mounting portions 12f at the flat portion 12c. As shown in Figs. 48 to 50, the mounting plate 12 is positioned at the engaging-portion-10-side of a body E1 of the encoder as in the first example in order to insert the protrusion 2b of the second-example insulating base 1 into the small hole 12b. Thereafter, the arms 12d are placed on and pushed onto the side plates 10d of the engaging member 10. The cut-and-raised portions 10e are positioned at the holes 12e in order to catch the arms 12d by the cut-and-raised portions 10e. This causes the mounting plate 12 to be snappingly stopped by the engaging member 10, whereby the mounting plate 12 is mounted to the engaging member 10. As shown in Figs. 48 to 50, when the mounting plate 12 is mounted, the flat portion 12c is placed upon an outer side of the plate-shaped base portion 10a of the engaging member 10. In addition, the arms 12d are mounted to the side plates 10d of the engaging member 10, at the left and right horizontal portions of the rotary member 8. Further, the bottom surfaces of the mounting portions 12f formed by bending from the side end portions of the arms 12d which extend in the rotational axial direction of the rotary member 8 are disposed at almost the same locations as the L-shaped terminal 7b of the common contactor 7 and the L-shaped terminal portions 6b of the contactors 6, which extend from the bottom surface of the second-example insulating base 1. As shown in Figs. 49 and 50, regarding the body E1 of the encoder in which the mounting plate 12 is mounted, the bottom side of the main base portion 2 and the bottom sides of the auxiliary base portions 5 are made to oppose a printed board P1 in order to insert the protrusions 12g into the holes of printed board P1. This causes the body E1 of the encoder to be positioned at the printed board P1, and the terminals 6b of the contactors 6, the terminal portion 7b of the common contactor 7, and the mounting portions 12f of the mounting plate 12 to be disposed on a wiring pattern (not shown) formed on the top surface of the printed board P1. The contactors 6, the common contactor 7, and the mounting plate 12 having the above-described structures are mounted to the surface of the wiring pattern by cream soldering in order to be mounted to the printed board P1. This causes the body E1 of the encoder which extends in a direction parallel to the rotational axial direction of the rotary member 8 to be mounted to the printed board P1, whereby the body E1 of the encoder is mounted in a standing manner. The operation of the rotary encoder having the above-described structures will be described. An operating member (not shown) is made to engage the hole 8f of the rotary member 8 as a result of passing it through the hole 12a of the mounting plate 12 and the engaging member 10, or the operating member is made to engage the hole 8f of the rotary member 8 from the opposite side. Thereafter, when the operating member is rotated, the rotary member 8 and the code member 9 are rotated with the shaft 8a as a support. The uneven portion 8d of the rotary member 8 is made to engage and disengage the engaging portion 10b to perform a clicking operation. In addition, the tongues 9b are made to contact with and separate from the contactors 6, and the common contactor 7 is made to contact the plate-shaped portion 9a at all times, so that a two-phase pulse signal is generated between the contactors 6 and the common contactor 7. Although in the above-described examples, a common pattern is used, the common contactor is not needed if one contactor has a plurality of contact portions, and at least one of the contact portions is made to contact the code pattern at all times.

Claims: A rotary encoder comprising: a rotary member (8) which is formed of an insulating material; and is of a columnar, cylindrical or truncated conical shape, a code member (9) mounted to the rotary member and formed of a metallic plate; and a plurality of contactors (6) which contact the code member; characterised in that the code member comprises an annular plate-shaped portion (9a) and a plurality of tongues (9b) formed as a result of bending from the plate-shaped portion; wherein the plate-shaped portion is disposed in a direction perpendicular to a rotational axial direction of the rotary member; and wherein the tongues are disposed so as to be exposed at a circumferential surface side of the rotary member. A rotary encoder according to Claim 1, wherein the tongues of the code member are formed as a result of bending from an outer or inner peripheral portion of the plate-shaped portion. A rotary encoder according to Claim 2, wherein the tongues of the code member are disposed at an outer circumferential surface side of the rotary member. A rotary encoder according to Claim 2, wherein the rotary member has a cylindrical shape, and wherein the tongues of the code member are disposed at an inner circumferential surface side of the rotary member. A rotary encoder according to any preceding claim, wherein the code member is embedded into the rotary member in order to be mounted to the rotary member. A rotary encoder according to any preceding claim, wherein the tongues of the code member are fitted into a groove (8h) formed in the circumferential surface side of the rotary member in order to mount the code member to the rotary member. A rotary encoder according to Claim 5, wherein the plate-shaped portion is disposed at an end surface side (8e) of the rotary member which extends perpendicular to the rotational axial direction of the rotary member. A rotary encoder according to any preceding claim, wherein the contactors are brought into contact with the plate-shaped portion and the tongues, wherein the plate-shaped portion is a common contact, and wherein the tongues are change-over contacts. A rotary encoder as claimed in Claim 1, comprising: a code pattern formed by the tongues (9b) at an external circumferential surface of the rotary member, wherein the plurality of contactors (6) contact the code pattern; a clicking uneven portion (8d) formed at an end surface of the rotary member; and an engaging member (10) adapted to engage and disengage with the uneven portion in order to form a click mechanism. A rotary encoder according to Claim 9, wherein a common pattern which is electrically conductive with the code pattern is formed at the other end surface of the rotary member which opposes the one end surface of the rotary member, and wherein a common contactor (7) is in contact with the common pattern. A rotary encoder according to Claim 10, wherein the plurality of contactors are disposed opposite each other, with the circumferential surface of the rotary member being disposed therebetween, wherein the engaging member is disposed so as to oppose the one end surface of the rotary member, and wherein the common contactor is disposed so as to oppose the other end surface of the rotary member. A rotary encoder according to Claim 11, wherein the contactors and the common contactor are mounted to an insulating base formed of an insulating material, and wherein the contactors, the common contactor, and the engaging member are provided so as to extend in the direction of the rotary member, with the insulating base as a reference surface.

Inventors: SASAKI MITSUYOSHI, TAKAHASHI KISABURO, SASAKI, MITSUYOSHI, TAKAHASHI, KISABURO, Sasaki, Mitsuyoshi, c/o Alps Electric Co., Ltd., Takahashi, Kisaburo, c/o Alps Electric Co., Ltd.
Applicants: ALPS ELECTRIC CO LTD, ALPS ELECTRIC CO., LTD.
Application year: 2000
Main classification: G01D5
IPC codes: G01D5