JPH09250934A - Normal rotation and reverse rotation detection encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a normal rotation and reverse rotation detection encoder which is composed of simple constitution, accurately detects the rotational speed and the rotation direction at the time of normal and reverse rotation of a motor, and in which timing setting of an output pulse is easily adjusted. SOLUTION: This encoder 90 is provided with a pair of rotary discs 59a-59b fixed on a rotary shaft A to detect normal and reverse rotation, a pair of photo-sensors 57a-57b paired with the pair of the rotary discs 59a-59b respectively and slit parts S composed of light transmission parts or light reflection parts formed on the rotary discs 59a-59b at the same intervals of the circumferential direction respectively. The slit part S group on the rotary discs 59a-59b are disposed to give the deviation of the phase except for 1/2 of the slit interval, and the pair of the photo-sensors 57a-57b are arranged in the same phase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward / reverse rotation detection encoder for detecting a rotation speed and a rotation direction.

[0002]

2. Description of the Related Art For example, when a motor is driven to rotate to drive a predetermined mechanism, a photo interrupter having a light emitting element and a light receiving element facing each other, and the two elements are intermittently cut off from each other in the circumferential direction. The rotation of the motor can be detected by an encoder provided with a rotating disk having slits formed at regular intervals, and the mechanism operation can be controlled based on this.

In a device that performs such control, the number of encoders is not increased as much as possible, and the number of encoders is increased as much as possible, so that the number of rotations and the direction of rotation of the motor during forward and reverse rotations can be accurately detected, and the output pulse timing is set. It is desirable to be able to make adjustments easily.

[0004]

SUMMARY OF THE INVENTION The present invention has a simple structure based on such a consciousness, and can accurately detect the number of rotations and the direction of rotation of the motor during forward and reverse rotations, and easily adjust the output pulse timing setting. The object is to provide a normal forward / reverse rotation detection encoder.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a pair of rotating discs fixed to a rotating shaft for detecting forward / reverse rotation; and a pair of photo plates respectively paired with the rotating discs. A sensor; and a slit portion formed of a light transmitting portion or a light reflecting portion formed on the pair of rotating discs at the same circumferential pitch, and the slit portion group on the pair of rotating discs has a slit interval. The pair of photosensors are arranged with a phase shift other than 1/2, and are arranged in the same phase.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on illustrated embodiments. In this embodiment, the present invention is applied to a rear group movement motor encoder provided in the lens shutter type zoom lens camera shown in FIG. First, the concept of the zoom lens camera will be described with reference to FIG. The lens configuration includes a front lens group L1 and a rear lens group L.
There are two groups of two.

[0007] The camera body includes an overall movement motor control means 60, a rear group movement motor control means 61, and a zoom operation means 6.
2, a shutter release means 63, a distance measuring device 64, a photometric device 65, and an AE motor control means 66 are provided.

When the zoom operating means 62 such as a zoom lever provided on the camera body is operated, the overall movement motor control means 60 controls the overall movement motor 25 to include a zoom lens including a front lens group L1 and a rear lens group L2. A movement command for moving the camera from the wide side to the tele side or a movement command for moving the tele side to the wide side is given. The focal length is changed and set to an arbitrary focal length by the operation of the zoom operating means 62 by the photographer. The image magnification of the viewfinder field is changed in association with the change of the focal length by the zoom operation means 62. Therefore, the photographer can know the change in the focal length due to the operation of the zoom operation means 62 by observing the change in the image magnification of the viewfinder field. The focal length set by the operation of the zoom operation means 62 can be recognized by a numerical value displayed on the LCD display panel (not shown), for example.

The overall movement motor control means 60 is also driven by the rear group movement motor control means 61 when the shutter release means 63 is operated.
At the same time, the whole movement motor 25 is driven to focus the zoom lens on the subject. The shutter release means 63 is
It is composed of a release button, and when it is pressed one step, it gives a distance measuring command to the distance measuring device 64 and a photometric command to the photometric device 65, and when it is pressed two steps, it performs a focusing operation and the AE motor control means 66. The shutter 27 of the AF / AE shutter unit 21 is operated via this. The shutter 27 receives the photometric output from the photometric device 65 and opens its shutter blade 27a for a predetermined time.

When operated, the zoom operating means 62 drives the whole moving motor 25 to move the front lens group L1 and the rear lens group L2 integrally. The rear lens group moving motor 30 may be operated via the rear lens group moving motor control means 61 at the same time as this movement, but an important point in this zoom lens camera is that the front lens group L1 and the rear lens group lens by the zoom operation means 62 are operated. It means that the movement of L2 is not performed in the conventional zooming concept in which the focal length is continuously changed without moving the focal position. That is, when the zoom operation means 62 is operated, only the whole movement motor 25 is operated to move the front lens group L.
1 and the rear lens group L2 are moved back and forth without changing the air gap between them, and both the overall movement motor 25 and the rear lens group movement motor 30 are operated to operate the front lens group L1 and the rear lens group L2. It is possible to move while changing the air gap between the two.

In the aspect, the subject at a specific distance cannot always be in focus. However, in the lens shutter type camera such as the present camera which does not observe the image by the photographing optical system, the subject is focused during the shutter release. There is no problem at all as it fits. Further, in the mode, while allowing the movement of the focal position, the front lens group L1 and the rear lens group L2 are moved, and both the overall movement motor 25 and the rear group movement motor 30 are operated at the time of shutter release to focus. .

After executing any one of the above control modes in accordance with the operation of the zoom operation means 62, the shutter release means 63 is operated in the focal length range of at least a part of the focal length set by the zoom operation means 62. Then, the whole moving motor 25 and the rear group moving motor 30
Both are operated to focus on the subject. The amount of movement of the front lens group L1 and the rear lens group L2 by the overall movement motor 25 and the rear group movement motor 30 at this time is not limited to the movement amount obtained from the subject distance information by the distance measuring device 64, and
It is determined in consideration of the movement amount obtained by the focal length information set by the zoom operation means 62. As described above, when the shutter release means 63 is operated, if the whole movement motor 25 and the rear group movement motor 30 are operated to perform the focusing operation, the degree of freedom in controlling the lens position is increased, and the control is performed. Will be easier.

Theoretically, when the zoom operation means 62 is operated, the whole moving motor 25 and the rear group moving motor 30 are operated.
The shutter release means 63 is operated by changing only the view field magnification and the focal length information of the finder without operating any of the above.
When the is operated, its focal length information and distance measuring device 64
The overall movement motor 25 and the rear group movement motor 30 are simultaneously operated according to the subject distance information according to, and the front group lens L1 and the rear group lens L2 are moved to positions uniquely determined by the focal length information and the subject distance information. You can also let it.

Next, an embodiment in which the zoom lens barrel of the above concept is embodied will be described mainly with reference to FIGS. 13 and 14. The schematic configuration and operation of the zoom lens barrel 10 will be described first. The first movable barrel 20 and the second movable barrel 20 will be described in order from the front.
A movable lens barrel 19, a third movable lens barrel 16, and a fixed lens barrel block 12 are provided. The third movable lens barrel 16 is screwed into the tubular portion of the fixed lens barrel block 12, and advances and retreats in the optical axis direction with rotation. The third movable lens barrel 16 has a linear guide cylinder 17 whose rotation is restricted, which moves integrally in the optical axis direction, inside, and the second movable lens barrel 19 rotates relative to the linear guide cylinder 17. While moving forward and backward along the optical axis. First movable lens barrel 2
0 is restricted in rotation, and moves forward and backward in the optical axis direction due to relative rotation with respect to the second movable lens barrel 19. The whole movement motor 25 is fixed to the fixed lens barrel block 12, and the shutter mount 4 having the AE motor 29 and the rear group movement motor 30 mounted thereon.
0 is fixed to the first movable lens barrel 20. The front lens group L1 is a lens having a positive power and is supported by the lens support barrel 34, and the rear lens group L2 is a lens support barrel 5.
It is a lens having a negative power supported by 0.

The fixed lens barrel block 12 fixed to the front of the aperture plate 14 of the camera body has a female helicoid 12a and a plurality of linear guide grooves 12b parallel to the optical axis O on the inner peripheral surface of its cylindrical portion. have. A code plate 13a having a predetermined pattern is fixed to the bottom of one of the plurality of straight guide grooves 12b. This code board 13
“A” is configured as a part of the flexible printed circuit board 13 located outside the fixed barrel block 12. The aperture plate 14 has an aperture 14a that determines the exposure area on the film.

The cylindrical portion of the fixed lens barrel block 12 has a gear accommodating portion 12c which bulges outward in the radial direction and extends in the optical axis direction.
Are formed (see FIG. 11). This gear storage 12
A drive pinion 15 that is long in the optical axis direction is rotatably accommodated in c. Both ends of the shaft 7 of the drive pinion 15 are rotatably supported by the support hole 4 provided in the fixed lens barrel block 12 and the support hole 31a provided in the gear support plate 31, respectively. The tooth surface of the drive pinion 15 projects to the inner peripheral surface of the fixed barrel block 12.

A third movable lens barrel 16 is screwed onto the inner circumference of the fixed lens barrel block 12. This third movable lens barrel 16
Is a plurality of straight guide grooves 16 extending in the optical axis direction on the inner peripheral surface.
c has a male helicoid 16a that engages with the female helicoid 12a of the fixed lens barrel block 12 and an outer peripheral gear 16b that engages with the drive pinion 15 on the outer periphery of the rear end portion (see FIG. 10).
And The drive pinion 15 is the third movable lens barrel 1
6 has an axial length that meshes with the outer peripheral gear 16 in the entire movement range of the optical axis direction 6.

On the inner circumference of the third movable lens barrel 16, a linear guide cylinder 17 is supported so as to be movable integrally with the third movable lens barrel 16 in the optical axis direction and relatively rotatable around the optical axis. . The linear guide cylinder 17 has a rear end flange portion 17d provided on the outer periphery of the rear portion with a plurality of engagement protrusions 17c protruding outward in the radial direction,
A retaining flange portion 1 having a smaller diameter than the flange portion 17d, which is provided in front of the rear end flange portion 17d with a slight gap.
7e and. A plurality of cutout portions 17f are formed in the circumferential direction of the retaining flange portion 17e. The third movable lens barrel 16 has a plurality of engagement protrusions 16d (FIG. 13) protruding inward in the radial direction on the inner circumference of the rear end portion.
Insert d from the above-mentioned notch 17f to insert both flanges 17
It is located in the gap between d and 17e, and is connected to the linear guide tube 17 by rotating relative to the linear guide tube 17. An aperture plate 23 having an opening 23a having substantially the same shape as the aperture 14a is fixed to the rear end surface of the linear guide cylinder 17. The engaging protrusion 17c is slidably engaged with the straight guide groove 12b parallel to the optical axis O of the fixed lens barrel block 12, and its rotation is restricted. A contact terminal 9 for slidingly contacting the code plate 13a and generating a signal corresponding to the focal length during zooming is fixed to the engaging projection 17c ', which is one of the engaging projections 17c.

The straight guide tube 17 also has an inner peripheral surface,
A plurality of straight guide grooves 17a parallel to the optical axis O and a plurality of lead grooves 17b penetrating the peripheral wall of the guide cylinder 17 and inclined with respect to the circumferential direction and the optical axis direction are formed.

A second movable lens barrel 19 is fitted on the inner circumference of the linear guide barrel 17. The second movable lens barrel 19 has a plurality of lead grooves 19 on the inner peripheral surface thereof, the lead grooves 19 having an inclination opposite to that of the lead grooves 17b.
c has a plurality of follower protrusions 19a having a trapezoidal cross-section, and a follower pin 18 located on the follower protrusions 19a. The follower pin 18 includes a ring member 18b and a center fixing screw 18a that supports the ring member 18b on the follower protrusion 19a. The follower protrusion 19a is
Slidably fitted in the lead groove 17b of the straight guide cylinder 17,
The follower pin 18 is the linear guide groove 1 of the third movable lens barrel 16.
6c is slidably fitted. Therefore, when the third movable lens barrel 16 rotates, the second movable lens barrel 19 rotates and moves straight in the optical axis direction.

A first movable lens barrel 20 is fitted on the inner circumference of the second movable lens barrel 19. The first movable lens barrel 20 engages a plurality of follower pins 24 provided on the outer periphery of the rear end portion with the corresponding inner peripheral lead grooves 19c, and the linear guide member 22.
Directed by. This linear guide member 22 is
As shown in FIGS. 6 and 7, an annular portion 22a, a pair of guide leg portions 22b extending from the annular portion 22a in the optical axis direction,
The straight guide groove 1 which is projected outward in the radial direction of the annular portion 22a.
7a and a plurality of engaging projections 28 slidably engaged with each other, and a guide leg portion 22b is inserted between the inner peripheral surface of the first movable lens barrel 20 and the AF / AE shutter unit 21 so as to be able to linearly guide. doing.

The annular portion 22a of the linear guide member 22 is
The second movable lens barrel 19 is coupled to the rear end of the second movable lens barrel 19 so as to be movable in the optical axis direction and rotatable relative to the optical axis. The rectilinear guide member 22 has a rear end flange portion 22d provided with a plurality of engaging projections 28 protruding outward in the radial direction on the outer periphery of the rear portion.
And a retaining flange portion 22c having a diameter smaller than that of the flange portion 22d, which is provided in front of the rear end flange portion 22d, and has a plurality of cutout portions 22e in the circumferential direction of the retaining flange portion 22c. It has (see FIG. 6). The second movable lens barrel 19 has a plurality of engagement projections 19b (FIG. 13) that project inward in the radial direction on the inner circumference of the rear end portion, and the engagement projections 19b are inserted from the cutout portions 22e to both sides. The linear guide member 22 is located in the gap between the flange portions 22c and 22d.
It is connected to the linear guide member 22 by rotating relative thereto. With the above configuration, when the second movable lens barrel 19 rotates in the forward and reverse directions, the first movable lens barrel 20 moves straight forward and backward with respect to the second movable lens barrel 19 while the rotation is restricted. To do.

A barrier device 35 having barriers 48a and 48b is attached to the front end of the first movable lens barrel 20,
The AF / AE shutter unit 2 provided with a shutter 27 including three shutter blades 27a (FIG. 1) on the inner peripheral surface.
1 is fitted and fixed. The AF / AE shutter unit 21 has a plurality of fixing holes 40a (FIG. 8) formed at equal angular intervals on the outer peripheral portion of the shutter mount 40.
The plurality of follower pins 24 also serve as fixing means for the AF / AE shutter unit 21, and the pin hole 20a formed in the first movable lens barrel 20 and the fixing hole 40a are
The follower pin 24 is fitted and fixed, and the shutter unit 21 is fixed to the first movable lens barrel 20 (see FIG. 9). The follower pin 24 can be fixed by, for example, bonding, screwing, or the like. Incidentally, 41 is the first movable lens barrel 20.
It is a decorative plate fixed to the front end of the.

The AF / AE shutter unit 21 is shown in FIG.
As shown in FIG. 3, the shutter mount 40 and the shutter blade support ring 4 fixed to the rear part of the shutter mount 40.
6 and a lens support barrel 50 (rear group lens L2) supported so as to be movable relative to the shutter mount 40. The shutter mount 40 has a front lens group L.
1, the AE motor 29 and the rear group movement motor 30 are supported. The shutter mount 40 has an annular portion having a photographing opening 40d through which the lens support tube 34 is inserted, and three leg portions 40b extending rearward from the annular portion. At two locations in the gap between the three leg portions 40b, the straight guide portion 40 which slidably engages the pair of guide leg portions 22b of the straight guide member 22 to guide movement.
c.

The shutter mount 40 further has an AE gear train 45A for transmitting the rotation of the AE motor 29 to the shutter 27.
And the rotation of the rear group movement motor 30 to the screw shaft 4
Lens drive gear train 42 </ b> A transmitted to the photo-interrupter 3 and the photo interrupters 56, 5 connected to the flexible printed circuit board 6.
7a and 57b and rotating discs 58, 59a and 59b having a large number of slits in the circumferential direction are supported. The photo interrupters 57a and 57b and the rotating disk 59a,
The rear group moving motor encoder 90 (see FIG. 2) for detecting the rotation of the rear group moving motor 30 is constituted by 59b, and the photo interrupter 56 and the rotating disk 58 constitute the rear group moving motor encoder 90.
An AE motor encoder that detects the rotation of the AE motor 29 is configured.

The shutter 2 is provided between the shutter mount 40 and the shutter blade support ring 46 fixed to the mount 40.
7, a support member 47 that pivotally supports the three shutter blades 27a of the shutter 27, and an annular drive member 49 that applies rotational force to the shutter blades 27a. The annular drive member 49 is provided with three operation protrusions 49a that engage with the three shutter blades 27a at equal angular intervals. The shutter blade support ring 46 is provided on the front wall portion with the photographing opening 4
6a and three support holes 46b provided at equal angular intervals around the photographing opening 46a, and the straight guide portion 4 is provided on the outer peripheral portion.
It has a bending restriction surface 46c exposed from 0c and slidably supporting the inner peripheral surfaces of the pair of guide leg portions 22b.

The support member 47 located in front of the shutter blade support ring 46 includes a photographing opening 47a facing the photographing opening 46a, and three shaft portions 47b (one in FIG. 1) facing the three supporting holes 46b. Only shown). Each of the three shutter blades 27a has, at one end, a shaft hole 27b through which the shaft portion 47b is inserted, and at the other end, a shielding portion that shields the photographing openings 46a and 47a.
Between the one end and the other end, there is an elongated hole 27c through which the operation protrusion 49a is inserted. The support member 47 includes shafts 47b that respectively support the shutter blades 27a.
The shutter blade support ring 46 is fixed to the corresponding shutter hole support ring 46 in a state of being fitted into the corresponding support hole 46b.

The annular drive member 49 has a gear train 4 on its outer peripheral portion.
It has a gear part 49b that receives rotation from 5A. Further, the support member 47 has three circular arc grooves 47c along the circumferential direction at positions close to the three shaft portions 47b. The three operation protrusions 49a of the annular drive member 49 penetrate the three arcuate grooves 47c to form the long holes 2 of the shutter blades 27a.
7c is engaged. The shutter blade support ring 46 is inserted from the rear side of the shutter mount 40 while supporting the annular drive member 49, the support member 47, and the shutter 27, and the fixing screw 90 inserted into the screw hole 46d provided in the peripheral portion. It is fixed to the shutter mount 40.

Behind the shutter blade support ring 46, a lens support cylinder 50 is disposed on the shutter mount 40 via slide shafts 51 and 52 so as to be relatively movable. The shutter mount 40 and the lens support cylinder 50 are urged to move away from each other by the coil spring 3 fitted to the slide shaft 51, thereby removing play between them. The drive gear 42a provided in the gear train 42 is restricted from moving in the axial direction, and a female screw is formed on the inner periphery thereof. A screw shaft 43 whose one end is fixed to the lens support cylinder 50 is screwed into this female screw, and these drive gears 42a are
The screw shaft 43 and the screw shaft 43 constitute a feed screw mechanism. Therefore, when the rear group movement motor 30 is rotationally driven to rotate the drive gear 42a in either forward or reverse directions, the screw shaft 43 moves forward and backward with respect to the drive gear 42a, and is supported by the lens support barrel 50, that is, the support barrel 50. The rear lens group L2 moves relative to the front lens group L1.

Pressing members 53 and 55 for pressing the motors 29 and 30 supported by the shutter mount 40 are screwed to the front of the shutter mount 40. Motors 29 and 30 and photo interrupters 56 and 57 are connected to the flexible printed circuit board 6 whose one end is fixed to the shutter mount 40. In a state where the first to third movable lens barrels 20, 19, 16 and the AF / AE shutter unit 21 are assembled, the aperture plate 23 is fixed to the rear end surface of the linear guide barrel 17, and the front end of the fixed lens barrel block 12 is fixed. An annular retaining member 33 is fitted in the portion.

Next, the forward / reverse rotation detecting encoder which is a feature of the present invention will be described.

When controlling the mechanism that operates by the forward and reverse rotations of the drive motor, the rotation speed and the rotation direction can be detected by an encoder as shown in FIG. 16, for example. In the figure, the encoder has a rotating disk 80 having slits S formed at regular intervals in the circumferential direction,
A pair of photo interrupters 81a and 81b are arranged at a predetermined angle in the circumferential direction of the rotating disk 80. In each of the photo interrupters 81a and 81b, a rotating disk 80 is commonly inserted in a gap between a light emitting element and a light receiving element which face each other. The pair of photo interrupters 81a and 81b
Are arranged at angular positions with the phase shifted with respect to the slit S by shifting the rotation angle by 94.5 ° as shown in FIG. 17, for example. Further, in the figure, the angle formed by the adjacent slits S provided on the rotary disk 80 is set to 18 °.

As described above, according to the above-mentioned encoder whose phase is shifted depending on the mounting angle of the photo interrupters 81a and 81b with respect to the rotary disk 80, it is possible to detect the rotation speed and the rotation direction of the drive motor and control the operation of the mechanism based on this. However, it is structurally difficult to obtain the mounting accuracy, and it is difficult to improve the accuracy of the output pulse. Furthermore, according to this encoder, when determining the number of slits and the slit width of the rotating disk 80, the photo interrupters 81a and 81a are designed.
The mounting angle of b must also be changed.

Therefore, in this embodiment, in order to solve such a problem, the forward / reverse rotation detecting encoder is constructed as follows. Hereinafter, an example in which this encoder is applied to the rear group movement motor encoder 90 provided in the present zoom lens barrel 10 will be described with reference to FIGS. 1 to 5.

That is, the rear group movement motor encoder 90 includes a pair of rotating discs 59a and 59b fixed to the rotating shaft A for detecting forward and reverse rotation, and a pair of rotating discs 59a and 59b, respectively. The pair of photo interrupters (photo sensors) 57a and 57b and the pair of rotating discs 59a and 59b have slits (light transmitting portions) S formed at the same circumferential pitch. The pair of photointerrupters 57a and 57b are arranged in a straight line as shown in FIG. 2 with their terminals t connected to the flexible printed circuit board 6, and the photointerrupters 57a and 57b are provided between the light emitting element and the light receiving element. A pair of rotating discs 59a and 59b fixed to both ends of the rotating shaft A are inserted into the gaps.

The slits S on the pair of rotary discs 59a and 59b are arranged with a phase shift other than 1/2 of the slit spacing, and the pair of photointerrupters 57a and 5b.
7b are arranged in the same phase. 3 and 4 show an example in which the slits S on the rotating disks 59a and 59b are arranged with a phase shift of 1/4 of the slit spacing, and the pair of photo interrupters 57a and 57b are arranged in the same phase. Is. By arranging the slits S on the rotating disks 59a and 59b and the photo interrupters 57a and 57b in this way, the pulse signal is output as shown in FIG.

That is, when the rear lens group moving motor 30 is rotated forward,
Photointerrupter 57a side and photointerrupter 57
On the b side, since the rotating discs 59a and 59b having the slits S provided with the phases shifted from each other are normally rotated, the light emitted from the light emitting unit to the light receiving unit is intermittently shielded. The pulse signal indicated by 5a is output. Also,
When the rear group movement motor 30 rotates in the reverse direction, the photo interrupter 5
On the 7a side and the photo interrupter 57b side, a rotary disk 59 provided with slits S provided so as to be out of phase with each other.
By rotating a and 59b in the opposite direction, the light projected from the light emitting portion to the light receiving portion is intermittently shielded,
This time, the pulse signal shown by b of FIG. 5 will be output.

The output pulse signals at the time of forward rotation and reverse rotation are
It is sent to the rear group movement motor control means 61 mounted on the camera body side via the flexible printed circuit board 6 (see FIG. 12). The control unit 75 includes a CPU and the like, and includes a rear group movement motor control means 61, an overall movement motor control means 60, an AE motor control means 66, a distance measuring device 64, a photometric device 65 and the like. A zoom operation unit 62, a shutter release unit 63, etc. are connected to the control unit 75. Then, the control unit 75 detects the number of rotations and the rotation direction of the rear lens group moving motor 30 based on the output pulse signal at the time of normal rotation and reverse rotation, and moves the rear lens group L2 accurately in the optical axis direction.

As described above, according to the present rear group movement motor encoder 90 to which the present invention is applied, the pair of rotating discs 59 is provided.
Since a and 59b are aligned on the rotation axis A, the same mounting seat surface 88 provided on the shutter mounting base 40 is provided.
It can be easily attached to (FIG. 1), the positional accuracy at the time of attachment is improved, and it is advantageous in assembly and inspection. Moreover, since the wiring shape of the flexible printed circuit board 6 can be simplified, the workability at the time of soldering to the printed circuit board 6 can be improved. Further, in designing, when determining the number of slits and the slit width of the rotating discs 59a and 59b, it is not necessary to change the attachment angle of the photo interrupters 57a and 57b, and it is sufficient to change the rotating discs 59a and 59b. . Further, for example, when the rotating discs 59a and 59b are integrally formed of a synthetic resin material, the rotating discs 59a and 59b
If the mold corresponding to one of the molds 59b can be rotated with respect to the other mold, the two rotary disks 59a, 59
The phase of b can be easily changed and determined, and the fine adjustment of the output pulse timing can be easily performed.

Therefore, according to the present invention, since the rear group moving motor 30 has a simple structure, the number of rotations and the direction of rotation of the rear group moving motor 30 can be accurately detected, and the adjustment of the output pulse timing setting is easy. The group moving motor encoder 90 can be obtained.

The pulse signal shown by c in FIG. 5 is output when the slits S on the pair of rotating discs 59a and 59b have a phase shift of 1/2 of the slit interval. , In this case high (H), low (L) at the same time
Since the signals (ON and OFF signals) are output, the rotation speed can be detected, but it is extremely difficult to detect the forward / reverse rotation of the rear group movement motor 30.

In the above embodiment, the rotary disk 59 is also used.
The pulse generation part and the non-pulse generation part of a and 59b were distinguished by the part in which the slit S was formed and the part in which the slit S was not formed, but there were a high reflectance part and a low reflectance part in which the light reflectivities differed greatly. It is also possible to distinguish between the pulse generator and the non-pulse generator. In this case, as shown in FIGS. 18 and 19, the high-reflectance portions S'are attached to the rotating discs 59a ', 59b'.
And the low reflectance portion 85 are alternately provided at the same circumferential pitch,
The large number of high-reflectance portions S'are pulse generators, and the low-reflectance portions 85 between the high-reflectance portions S'are non-pulse generators. Alternatively, by reversing this relationship, the low reflectance portion 85 can be used as the pulse generating portion and the high reflectance portion S'can be used as the non-pulse generating portion. The rotating discs 59a ', 5 having such a configuration
The rear group movement motor encoder 90 'using 9b' can also achieve the same effects as the above embodiment.

In this embodiment, the front lens group L1 and the rear lens group L2 are respectively provided in the AF / AE shutter unit 21.
The AE motor 29 and the rear group movement motor 30 are mounted on the unit 21 as one of the components. According to this configuration, there is an advantage that the supporting structure and the driving structure of the front group lens L1 and the rear group lens L2 can be simplified, but at least one of the front group lens L1 and the rear group lens L2 is
Shutter mount 40, annular drive member 49, support member 4
The present zoom lens can be realized even if the AF / AE shutter unit 21 including the shutter 7, the shutter 27, the shutter blade pressing ring 46, and the like is provided as a separate member and is supported by a support member different from the unit.

The present zoom lens camera operates as follows. FIG. 13 in which the zoom lens barrel 10 is most retracted.
When the power switch (not shown) is turned on in the lens housed state, the whole movement motor 25 is driven to rotate in the positive direction by a slight amount. Then, this rotation is transmitted to the drive pinion 15 via the gear train 26 supported by the support portion 32, and the third movable lens barrel 16 is rotated in the payout direction.
The movable lens barrel 19 and the first movable lens barrel 20 are the third movable lens barrel 16 and
At the same time, it is slightly extended in the optical axis direction, and the camera is ready for shooting with the zoom lens positioned at the wide end.

When the zoom operation means 62 is operated to the tele side in this photographing possible state, the whole movement motor 25 is rotationally driven in the positive direction via the whole movement motor control means 60, and the driving pinion 15 and the outer peripheral gear 16b are used. The third movable lens barrel 16 is rotated in the feeding direction. Therefore,
The third movable lens barrel 16 is extended from the fixed lens barrel block 12 due to the relationship between the female helicoid 12a and the male helicoid 16a, and at the same time, the straight guide tube 17 is fixed by the relationship between the engagement projection 17c and the straight guide groove 12b. Block 12
With respect to the third movable lens barrel 16, the lens moves forward along the optical axis in a state where it does not relatively rotate. At this time, the second movable lens barrel 19
Attaches the follower pin 18 to the lead groove 17b and the straight guide groove 1
By being engaged with 6c at the same time, the third movable lens barrel 16 is relatively rotated in the same direction and relatively moved forward of the optical axis with respect to the movable lens barrel 16. Also, the first movable lens barrel 20 is
Since the linear guide member 22 linearly guides and the follower pin 24 is moved and guided by the lead groove 19c, the second movable lens barrel 19 and the AF / AE shutter unit 21 together with the fixed lens barrel block 12 do not rotate relative to each other. Advance to the front of the optical axis.

Since the rear lens group moving motor 30 is not driven while the zoom lens barrel 10 is driven in this way, the front lens group L1 and the rear lens group L2 are integrally integrated with each other while keeping a constant distance from each other. (See FIG. 12). The focal length set by the zoom operation means 62 is displayed by the display means (not shown).

When the release button is pushed one step at an arbitrary focal length set by the zoom operating means 31, a distance measuring command is given to the distance measuring device 64 and a light measuring command is given to the light measuring device 65 to measure the distance and Photometry starts. Thereafter, when the release button is depressed two steps, both the whole moving motor 25 and the rear group moving motor 30 move the moving amount obtained by the distance measuring device 64 based on the subject distance information and the focus set by the zoom operating means 31. The AE motor control means 6 moves the front lens group L1 and the rear lens group L2 by a movement amount determined in consideration of the movement amount obtained from the distance information to set the focal length and focus on the subject.
The AE motor 29 rotationally drives the annular driving member 49 in accordance with the subject luminance information from the photometric device 65 via 6 to drive the shutter 27 so as to satisfy a predetermined exposure. After completion of the shutter release, both the whole movement motor 25 and the rear group movement motor 30 are immediately driven to return the front group lens L1 and the rear group lens L2 to the state before the shutter release.

When the zoom operating means 62 is operated to the wide side, the whole moving motor 25 is rotationally driven in the reverse direction, and
The movable lens barrel 16 is rotated in the retracting direction and retracted into the fixed lens barrel block 12 together with the linear guide barrel 17. At the same time, the second movable lens barrel 19 is retracted with respect to the movable movable lens barrel 16 while rotating in the same direction as the third movable lens barrel 16.
The movable lens barrel 20 has a position A relative to the rotating second movable lens barrel 19.
It is pulled in together with the F / AE shutter unit 21.
Also during this retraction drive, the rear group moving motor 30 is not driven, as in the above-described retraction drive. Then, when the power switch is turned off after the zoom lens has moved to the wide end position, the zoom lens barrel 10 is retracted to the lens storage position shown in FIG. 13 by the overall movement motor 25 that is rotationally driven based on this.

[0049]

As described above, according to the present invention, it is possible to accurately detect the number of rotations and the direction of rotation of the motor during forward and reverse rotations with a simple structure, and to adjust the output pulse timing setting easily. A rotation / reverse rotation detection encoder can be provided.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an AF / AE shutter unit including an encoder for a rear lens group moving motor to which the present invention is applied.

FIG. 2 is an enlarged perspective view showing an encoder for a rear group movement motor of the same.

FIG. 3 is a diagram showing an encoder for the rear group movement motor of FIG.
It is the side view seen in the direction.

FIG. 4 is an IV-IV of FIG. 2 of the encoder for the rear group movement motor of the same.
It is a side surface sectional view which follows a line.

FIG. 5 is a timing chart showing a pulse signal output from the rear group moving motor encoder during forward and reverse rotation of the rear group moving motor.

FIG. 6 is a perspective view showing a main part of a mechanism for linearly guiding the AF / AE shutter unit of the present embodiment.

7 is a perspective view showing a main part of a mechanism that guides the AF / AE shutter unit in a straight line in a state different from that in FIG.

FIG. 8 is an exploded perspective view showing main members of the same AF / AE shutter unit.

FIG. 9 is a perspective view showing a state where the AF / AE shutter unit is assembled to a first movable lens barrel.

FIG. 10 is a third view of the zoom lens barrel of the present embodiment.
It is a perspective external view which shows a movable lens barrel.

FIG. 11 is a perspective external view showing a fixed lens barrel block of the zoom lens barrel.

FIG. 12 is an upper half sectional view showing a maximum extended state of the zoom lens barrel.

FIG. 13 is an upper half cross-sectional view showing a main part of the zoom lens barrel in a lens housed state.

FIG. 14 is an exploded perspective view showing the entire zoom lens barrel.

FIG. 15 is a block diagram showing a control system for controlling the operation of the zoom lens barrel.

FIG. 16 is a perspective view showing a comparative example with respect to an encoder for a rear lens group moving motor to which the present invention is applied.

FIG. 17 is a side view of a rear group movement motor encoder in the comparative example.

FIG. 18 is a side view showing another embodiment of the encoder for rear group movement motor to which the present invention is applied.

FIG. 19 is a side sectional view showing the rear group moving motor encoder.

[Explanation of symbols]

57a 57b Photointerrupter (photosensor) 57a '57b' Photointerrupter (photosensor) 59a 59b Rotating disc 59a '59b' Rotating disc 85 Low reflectance part (slit part, light reflecting part) 90 90 'Rear group moving motor Encoder (forward / reverse rotation detection encoder) A rotating shaft S slit (slit part, light transmitting part) S'high reflectance part (slit part, light reflecting part)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01L 31/12 H01L 31/12 D G02B 7/04 E

Claims (3)

[Claims] 1. A pair of rotating discs fixed to a rotating shaft for detecting forward and reverse rotations; a pair of photosensors respectively paired with the pair of rotating discs; and a pair of rotating discs, respectively. A slit portion formed of a light transmitting portion or a light reflecting portion formed at the same circumferential pitch; and the slit portion group on the pair of rotating discs gives a phase shift other than 1/2 of the slit interval. The forward rotation / reverse rotation detection encoder, wherein the pair of photosensors are arranged in the same phase. 2. The forward / reverse rotation detection encoder according to claim 1, wherein the light transmitting portion is a large number of slits provided on the rotating disk at the same circumferential pitch. 3. The rotating disk according to claim 1, wherein high reflectance portions and low reflectance portions having different light reflectances are alternately provided at the same circumferential pitch, and the plurality of high reflectance portions or A forward / reverse rotation detection encoder in which the light reflecting portion is configured by either one of the low reflectance portions.