Optical encoder

[Detailed Description of the Invention]

[Industrial Application] The present invention relates to the optical Rokari encoder which starts an optical encoder, especially can set up automatically the mutual position of a light-emitting part, a primary detecting element, and a numerals board at the time of the attachment to the axis of rotation. [Description of the Prior Art] The optical encoder is extensively used for apparatus like a plotter in order to detect the speed and the axial position of the inside electric motor of apparatus, for example. As shown in United States patent 4.451st given to a mark, G, and Mr. Leonard on April 29, 1984, and No. 731, an optical encoder contains a luminescent organ, the numerals board (wheel) mounted in a motor shaft, an optical power detector, and a controller. A detector changes the light modulated by the revolving numerals wheel into the signal which can be used in order that a controller may detect rotation of an axis. In order to carry out sensitivity of an encoder to the utmost, between a luminescent organ and a detector, a numerals wheel is arranged correctly and must set up precisely the gap (luminescence gap) of a luminescent organ and a numerals wheel, and the gap (detector gap) of a numerals wheel and a detector. In prior art, since the numerals wheel needed to be manually assembled on the motor shaft, the above-mentioned gap setup was difficulty and a cost overrun. For example, in order for the 730 type numerals machine of dynamic Research Corporation to set up a gap, it is necessary to remove it between a numerals wheel and an encoder housing, and a formula spacer needs to be used for it. Time and effort is taken, an error is produced and such equipment is Easy (a possibility of producing damage is on a numerals wheel.). In the case of the M1515 type mark of BEI Moshigon System Corporation, in order to attach a numerals wheel firmly on an axis and to push a numerals wheel on a desired axial position, it is not necessary to use the spacer for a gap setup by using a gap stick. However, though it is regrettable, such a numerals wheel can be arranged only under dynamic conditions, and positioning may be inaccurate on account of flexibility, and damage may arise on a numerals wheel. [The modular form optical encoder based on the problem and the solving means] present invention which it is going to solve needs neither gap setting tools nor dynamic conditions, but it aims at enabling * positioning of a numerals wheel easily. An encoder contains the housing containing a luminescent organ / detector module, a cover, and the numerals wheel arranged between a luminescent organ and a detector. Since the cover is attached to the housing, enabling free rotation, the cam on a cover engages with the follower part on a housing, and arranges a cover to the axial predetermined position in a housing. When attaching a motor to an encoder, a motor shaft pushes aside a numerals wheel to a cover, and the direction of an axis is positioned for a numerals wheel on a motor shaft by it, and the gap of a luminescent organ and a detector is set up. Once a numerals wheel is fixed to an axis, a cover can be retracted and rotation of a numerals wheel can be freely enabled with a motor shaft. Since the manufacture common difference of an encoder part article is strictly manageable, a gap becomes exact. [Example] Drawings [ 1 and B 1 ] A show optical encoder 1 concerning the example manufactured based on the present invention. Encoder 1 is mounted in electric motor 3 which has axis 5. It is very important to detect the position and revolving speed of axis 5 precisely in many uses, for example, a plotter. The exposure end of axis 5 is given to the load that predetermined rotation driving force is not illustrated, and, on the other hand, the opposite end is restrained in encoder 1 for a position and speed detection. Drawing 2 is to Drawing 1. - It is an exploded view of encoder 1 shown in Drawing 1 B. encoder 1 -- base 11 A and an attachment component (retainer) -- the all are manufactured from the plastic using injection molding technique including 13, cover 21, and housing 23. Numerals machine 1 contains numerals wheel 17 for carrying out the intermittence abnormal conditions of the light between luminescent organ part 27 of a luminescent organ / detector module 15, and detector section 29 further. Although it is not necessary to use the combination module of a luminescent organ/detector, it is important to control the size and relative gap of a luminescent organ and a detector strictly. Numerals wheel 17, and a luminescent organ / detector module 15 may be the same as what is used by optical encoders, such as a HE D S-9000 type of the Hewlett Paracard. What is necessary is just to insert in each part article simply, in order to assemble encoder 1 first. the beginning -- cover 21 -- the [ Drawing 3 and ] -- as shown inA [ 7 ] figure, it attaches to housing 23. Next, numerals wheel 17 is arranged for the course between luminescent organ 27 of module 15, and detector 29. As for numerals wheel 17 and module 15, both sides are stationed in housing 23, and module 15 is fitted in into housing 23 (press fitted). Next, in order that attachment component 13 may protect numerals wheel 17, it is snap The carried out into housing 23 (snap fitted). The snap stop of the base 11 may be carried out to housing 23 also in the state (+, oose) where it is not fixing to storage of the first stage before mounting to motor 3, and loading. now and numerals wheel 17 -- luminescent organ 27 and detector 29 -- although located in between [ which ], it is not fixed but this is freely movable to the direction of an axis, and a diameter direction slightly. In order to attach encoder 1 to motor 3, base 11 is first removed from housing 23 five, and then it attaches to motor 3 with three screws. Position Agreement of the housing 23 (cover 21, a luminescent organ / detector module 15, numerals wheel 17, and attachment component 13 are included) is carried out with axis 5 and base 11, then it is pushed on motor 3, and is attached to base 11 by eye snap The. Drawing 3 shows the transverse cross section of housing 23 attached to base 11 (not shown) with snap leg 31.33. Base 11 the very thing is attached to motor 3 (not shown). In Drawing 3, in order to clarify a drawing, attachment component 13 is not illustrated. During an assembly, if axis 5 is inserted in boss 17 of a numerals wheel, boss 19 of a numerals wheel will be pressed to following table side 21a of cover 21. Axis 5 reaches from motor 3 to Reign in cover 21 through numerals wheel 17 and boss 19. The intimateness [ each other ] which the axis to boss 19 inserts in can be set up changing boss's 19 inside diameter, or by adding rubber or the friction ring made from a plastic as boss's 19 parts. numerals wheel 17 is spread in bolting bound tight by hexagonal wrench 7 shown in Drawing 1 -- not illustrating -- it uses and is fixed to axis 5. A lever may be attached to it in order to press boss 19 densely to following table side 37, if hexagonal wrench 7 is necessary. Drawing 3 shows cover 21 which protrudes in housing 23 only for a prescribed distance which is specified with the size of housing 23 and cover 21. If it is in the position where cover 21 protruded and to illustrate, boss 19 will be pressed to following table side 21a of cover 21, and the axial position of numerals wheel 17 will be specified by the size and the given gap of numerals wheel 17 and boss 19. Therefore, the gap with a luminescent organ and a detector becomes settled only with the size of housing 21, cover 23, numerals wheel 17, boss 19, and a luminescent organ / detector module 15. Since it is comparatively easy to maintain strict common difference with the present production technology, the gap with a luminescent organ and a detector is complicated, its time-consuming fabrication process is unnecessary, and it can set it up correctly and repetitively. ' figure 4 shows the transverse cross section of numerals machine 1 in the active position where cover 21 protruded, and the drawn position. If numerals wheel 17 is fixed to the axial predetermined position of axis 5, it will draw in cover 21 and rotation of numerals wheel 17 and boss 19 will be freely attained with axis 5. Drawing 5 shows the upper surface figure of cover 21 containing three cams 47 which project from circumference side 49. Drawing 6 shows the bottom view of housing 23 containing lower follower part 45 for fixing rail 41 and cover 21. Housing 23 also contains further three follower parts 43 which can Feeling in cam 47 and the diameter direction of cover 21. the -- the [A / 7 / figure and ] --B [ 7 ] figure shows the detail view of the interaction of cover 21 and housing 23. the [ Drawing 3 thru/or ] --B [ 7 ] figure shows the interaction of cover 21, and housing 23 and boss 19. the [ Drawing 3 and ] -- cam 47 engages with follower part 43, andA [ 7 ] figure shows the state where cover 21 rotated to the protrusion position which presses cover 21 in the direction lower part of an axis to the prescribed position in housing 23. Circumference ring 49 of cover 21 is being fixed in housing 23 between rail 41 and lower follower part 45. the [ Drawing 4 and ] --B [ 7 ] figure shows cover 21 which rotated to the drawing-in position which cam 47 detaches and attaches from follower part 43. If two-step cam 51 containing projecting two-step cam 51 which engages with lower follower part 45 engages with stop 45 below circumference ring 49, cover 21 will withdraw and will be pressed above the direction of an axis in a position. The projection position and depression position of cover 21 which positions a numerals board in the above-mentioned example are although explained as composition for which it opts by the follower part and cam like illustration, What consists the movable member which contacts a numerals board (hole) in a predetermined stable position like the projection position in not the thing limited to this but the above-mentioned example, and defines the direction position of an axis of a numerals board correctly in the position is contained in the technical thought of the present invention. (Effect] Since the present invention is constituted as mentioned above and it acts, in the time of the attachment to the time of rotation of an encoder, the effect that the position of the numerals board to a luminescent organ and an optical power detector can be decided correctly and quickly, and easily is acquired.

[Brief Description of the Drawings]

applying a drawing to the example of the present invention -- the -- the [A / 1 / figure and ] -- the perspective view showing the state whereB [ 1 ] figure attached the optical encoder to the motor, It is a sectional view of the encoder in the state where Drawing 2 is shown in the exploded perspective view of an encoder, and Drawing 3 has a cover in an example barrel projection position of a stable position, Drawing 4 -- cover 21 -- a stable position -- an example -- the sectional view of the encoder in the state of being in a depression position, and Drawing 5 -- the front view of cover 21, and Drawing 6 -- the [ the blue side figure of housing 23, and ] -- the [A / 7 / figure and ] --B [ 7 ] figures are cover 21 and an important section perspective view of housing 23. 1: Optical Encoder 2: -- Motor, 17:Numerals Board (Numerals Wheel), and 21:Positioning Means -- an Example -- Cover and 23:Support Means -- an Example -- Housing, 27:Luminescent Organ, 29:Optical Power Detector, and 43: -- the -- Follower Part of One 45: -- the -- Follower Part of Two, and 47: -- 1st Cam, 51: The 2nd cam.