Information
-
Patent Grant
-
6784383
-
Patent Number
6,784,383
-
Date Filed
Tuesday, June 24, 200321 years ago
-
Date Issued
Tuesday, August 31, 200419 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Wenderoth, Lind & Ponack, L.L.P.
-
CPC
-
US Classifications
Field of Search
US
- 200 11 R
- 200 11 G
- 200 11 A
- 200 11 D
- 200 11 DA
- 200 11 TW
- 200 17 R
- 200 14
- 200 18
-
International Classifications
-
Abstract
A rotary encoder having a slider provided with a plurality of movable contact points disposed along a circle of a certain radius at an angular interval six times as large as an output pitch of rectangular wave signal. The contact-point board is provided on the surface with a signal pattern and a common pattern. Signal pattern consists of three fixed contact points, each having two conductive layers of radial shape of the same width, disposed at an angular pitch which is three times as large as the output pitch of rectangular wave signal. These fixed contact points are disposed along sliding circle of the movable contact points, at an angular pitch which is smaller, or larger, than angular interval of movable contact points, or a multiple of it, by the output pitch of rectangular wave signal, or twice that. Common pattern is disposed insulated from the signal pattern. Overall size of the rotary encoder is small in the outer diameter, and the encoder generates three-phase rectangular wave signal.
Description
TECHNICAL FIELD
The present invention relates to a rotary encoder that outputs three-phase rectangular wave signals, used for input operations, etc. in various kinds of electronic apparatus.
BACKGROUND ART
A conventional rotary encoder which outputs multi-phase rectangular wave signals is disclosed in Japanese Utility Model Laid-Open No. H3-26021, and in Japanese Patent Laid-Open Application No. H6-94476. Each of the conventional rotary encoders has a ring-shape common pattern disposed at the center of contact-point board, and a teethed ring-shape signal pattern disposed around outside of the common pattern. The signal pattern is provided for a number of phases of the output signal, disposed concentric to the common pattern. Each of the rotary encoders further has a slider, provided to be revolvable so that its movable contact points slide on the respective patterns to generate multi-phase rectangular wave signals. For example, a three-phase encoder is provided with three signal patterns. The contact-point boards used in conventional rotary encoders have large outer diameter. Therefore, the overall outer dimensions of the rotary encoder become bulky, and this makes it difficult to use the rotary encoder in a high-density compact electronic apparatus.
DISCLOSURE OF INVENTION
A rotary encoder in the present invention has a slider supported to be revolvable with respect to a contact-point board, which slider having a plurality of movable contact points disposed on a circle of a certain radius from the revolution center at an angular interval that is six times as large as the output pitch of rectangular wave signal. The rotary encoder further has, on the contact-point board, an electroconductive signal pattern and a common pattern, which make contact with the slider. The signal pattern has three fixed contact points along a sliding circle of the movable contact points. Each of the fixed contact points has two conductive layers of the same width disposed in radial arrangement having mutual electrical conduction. Angular pitch of the radial conductive layers is three times as large as the output pitch of rectangular wave signal. Angular pitch of the three fixed contact points is smaller, or larger, than the angular interval, or a multiple of it, of the movable contact points by the output pitch of rectangular wave, or twice that. Furthermore, it is larger than angular width of one of the fixed contact point. The common pattern is insulated from the signal pattern, and disposed on a sliding circle of the same radius as the movable contact points of slider. When any one of the movable contact points of the slider is making contact with any one of the fixed contact points of signal pattern, the common pattern is having contact with at least one of the rest of the movable contact points.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a cross sectional side view of a rotary encoder in accordance with a first exemplary embodiment of the present invention.
FIG. 2
is a plan view of a slider, which being the key portion of the rotary encoder in accordance with the first exemplary embodiment of the present invention.
FIG. 3
is a conceptual drawing of a contact point pattern on a contact-point board, which pattern being the key portion of the rotary encoder in accordance with the first exemplary embodiment of the present invention.
FIG.
4
-
FIG. 9
are conceptual drawings that describe couplings between the contact point pattern of the contact-pattern board and the movable contact points of the slider, in the rotary encoder in accordance with the first exemplary embodiment of the present invention.
FIG. 10
is a waveform chart of a three-phase rectangular wave signal generated by the rotary encoder in accordance with the first exemplary embodiment of the present invention.
FIG. 11
is a conceptual drawing of another contact point pattern on the contact-point board, which pattern being the key portion of the rotary encoder in accordance with the first exemplary embodiment of the present invention.
FIG. 12
is a conceptual drawing of a still other contact point pattern on the contact-point board, which pattern being the key portion of the rotary encoder in accordance with the first exemplary embodiment of the present invention.
FIG. 13
is a plan view of a slider, which being the key portion of a rotary encoder in a second exemplary embodiment of the present invention.
FIG. 14
is a conceptual drawing of a contact point pattern on a contact-point board, which being the key portion of the rotary encoder in the second exemplary embodiment of the present invention.
FIG.
15
-
FIG. 18
are conceptual drawings that describe couplings between the contact point pattern of the contact-point board and the movable contact points of the slider, in the rotary encoder in the second exemplary embodiment of the present invention.
FIG. 19
is a waveform chart of a three-phase rectangular wave signal generated by the rotary encoder in the second exemplary embodiment of the present invention.
FIG. 20
is a conceptual drawing of another contact point pattern on the contact-point board, which being the key portion of the rotary encoder in the second exemplary embodiment of the present invention.
FIG. 21
is a conceptual drawing of a still other contact point pattern on the contact-point board, which being the key portion of the rotary encoder in the second exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
(Embodiment 1)
The outline structure of a rotary encoder in the present invention is described referring to
FIG. 1
, a cross sectional side view. Operation shaft
1
is supported to be revolvable in bearing
2
, operation shaft
1
holds at holding portion
1
A, which is provided in the lower part, slider
11
made of a thin elastic metal sheet, and bearing
2
is engaged at the bottom part with case
5
. The inner bottom surface of case
5
functions as contact-point board
13
. Movable contact points
12
A-
12
C of slider
11
are adopted to make contact with contact point pattern
14
disposed on contact-point board
13
.
When operation shaft
1
is revolved, movable contact points
12
A-
12
C of slider
11
make sliding motion on contact point pattern
14
. As the result, rectangular wave signal is continuously outputted from terminals
8
connected with respective lead out sections of contact point pattern
14
.
Bearing
2
is provided at the bottom with clicking spring
9
made of a thin elastic metal sheet, so that it is adopted to make contact with notches provided on the upper surface of holding portion
1
A of operation shaft
1
. Clicking spring
9
generates a clicking feeling in accordance with outputting of rectangular wave signal generated as the result of sliding motion of slider
11
.
As described in the above, specific points of feature of the rotary encoder in the present embodiment are in the structure of contact points. The points of feature of the rotary encoder, which generates rectangular wave signal during one revolving motion, a 360° revolution, are described, hereinafter.
The rotary encoder in the present embodiment is an 18-signal type, which generates three-phase rectangular wave signal at a 20° pitch, or 18 signals continuously for a 360° revolution.
FIG. 2
shows a plan view of the slider in the rotary encoder in the present embodiment.
FIG. 3
is a conceptual drawing of the contact point pattern disposed on the contact-point board.
As shown in
FIG. 2
, slider
11
is provided with three movable contact points
12
A,
12
B and
12
C disposed along a circle of a certain radius from the revolution center. Movable contact points
12
A,
12
B and
12
C are disposed at an interval of 120°, and are adopted to make contact with the upper surface of contact-point board
13
, as illustrated in FIG.
1
. The interval of movable contact points
12
A,
12
B,
12
C is 6 times as large as the output pitch 20° of rectangular wave signal. Movable contact points
12
A-
12
C may have one contact tip each; however, in order to ensure a stable contact, it is preferred that each has two contact tips as illustrated in FIG.
2
. Of course each may have three or more contact tips.
On the surface of contact-point board
13
, contact point pattern
14
is provided, which pattern consisting of signal pattern
15
and common pattern
16
, as shown in FIG.
3
. Signal pattern
15
consisting of fixed contact points
17
,
18
and
19
is disposed along a circle having the same radius as movable contact points
12
A-
12
C. Fixed contact point
17
is formed of two conductive layers
17
A,
17
B of the same angular width 10° disposed in a radial arrangement, which share a common lead out section
17
C. Conductive layers
17
A,
17
B are disposed at an angular pitch 60°, which angle being three times as large as the output pitch 20° of rectangular wave signal. Fixed contact points
18
and
19
are also provided in the same configuration; having a lead out section
18
C and a lead out section
19
C, and two conductive layers
18
A,
18
B and conductive layers
19
A,
19
B, respectively.
Angular pitch of fixed contact points
17
and
19
is 160°, which angle being larger than angular interval 120° of movable contact points
12
A-
12
C of slider
11
by twice the output pitch 20° of rectangular wave signal. Respective angular pitches of fixed contact points
17
,
18
and
18
,
19
are 100°, which angle being smaller than angular interval 120° of movable contact points
12
A-
12
C of slider
11
by the output pitch 20° of rectangular wave signal. Either of the pitches is larger than one angular width 70° of fixed contact points
17
-
19
.
In the spaces between fixed contact points
17
and
19
, between conductive layers
18
A and
18
B, and between conductive layers
19
A and
19
B, fan-shape conductive layers
16
A,
16
B and
16
C of common pattern
16
are disposed, respectively. Conductive layers
16
A,
16
B and
16
C are disposed on contact-point board
13
along a circle of the same radius as movable contact points
12
A-
12
C at such regions where signal pattern
15
in not disposed. Conductive layers
16
A,
16
B and
16
C are connected with lead out section
16
E, and disposed insulated from signal pattern
15
. Conductive layers
16
A,
16
B and
16
C are disposed at such locations of angular arrangement; where, while one of movable contact points
12
A-
12
C is having contact with any one of conductive layers
17
A,
17
B,
18
A,
18
B,
19
A and
19
B, at least one other movable contact point among
12
A-
12
C makes contact with the conductive layer
16
A,
16
B,
16
C. Namely, the location formed between conductive layers
17
A and
17
B, as shown in
FIG. 3
with dotted lines, does not need to have it.
All of the conductive layers, lead out sections and portions connecting the conductive layers with lead out sections, viz. those constituting contact point pattern
14
, should preferably be provided by punching a thin metal sheet; and integrating them with resin case
5
by insert molding. Thereby, they can be provided at high precision in terms of relative positioning.
Various states of coupling between contact point pattern
14
of contact-point board
13
and movable contact points
12
A-
12
C of slider
11
are described referring to FIG.
4
through
FIG. 9
, hereinafter.
As shown in
FIG. 4
, in the normal state before revolving operation shaft
1
, clicking spring
9
is in engagement with a notch provided on the upper surface of holding portion
1
A. Slider
11
is having conductive contact with common pattern
16
. However, slider
11
is having no contact with any one of fixed contact points
17
-
19
. Namely, it is standing still at open state. Namely, in the state as illustrated in
FIG. 4
, only movable contact point
12
C is staying on conductive layer
16
C to make contact, but the remaining movable contact points
12
A,
12
B are at places where there are no signal pattern
15
. In the above-described normal state, or open state, lead out section
16
E of common pattern
16
has no electrical conduction with any one of lead out sections
17
C,
18
C and
19
C of signal pattern
15
.
Starting from the above-described open state, operation shaft
1
is revolved to provide slider
11
with clockwise sliding motion along contact point pattern
14
. Concept of the shifting state of contacts is shown in FIG.
5
through FIG.
9
.
FIG. 5
shows a state where slider
11
is revolved clockwise and staying somewhere in an angular range between approximately 5° and approximately 10°. Movable contact point
12
A is making contact with conductive layer
17
A, at the same time movable contact points
12
B,
12
C are having contact with conductive layers
16
B,
16
C, respectively. Thus, lead out section
16
E and lead out section
17
C are in electrical conduction to each other.
When slider
11
is revolved further clockwise, movable contact point
12
A leaves from conductive layer
17
A, as shown in FIG.
6
. Namely, movable contact points
12
A-
12
C are again put into open state for approximately 10° angular range. Namely, these movable contact points have no contact with any one of fixed contact points
17
-
19
of signal pattern
15
. Thus, lead out section
16
E has no conduction with any one of lead out sections
17
C-
19
C.
When slider
11
is revolved further, movable contact point
12
C comes into contact with conductive layer
19
B for approximately 10° angular range, ref FIG.
7
. Movable contact point
12
B also comes into contact with conductive layer
16
B. Lead out section
16
E and lead out section
19
C are put into conduction state to each other.
When slider
11
is revolved further, movable contact point
12
B comes into contact with conductive layer
18
B as shown in
FIG. 8
, after having an open state of approximately 10° angular range. Lead out section
16
E and lead out section
18
C are put into conduction state to each other.
When slider
11
is revolved further, movable contact point
12
A comes into contact with conductive layer
17
B, as shown in
FIG. 9
, after having an open state of approximately 10° angular range. Lead out section
16
E and lead out section
17
C are again put into conduction state to each other.
When slider
11
is further revolved, lead out section
16
E and lead out section
19
C are put into conduction state, and after that lead out section
16
E and lead out section
18
C are put into conduction state to each other.
As described in the above, the clockwise sliding motion of slider
11
brings lead out section
16
E of common pattern
16
into conduction state with respective lead out sections
17
C,
19
C and
18
C of fixed contact points
17
,
19
and
18
of signal pattern
15
, one after the other in the order. The conduction state is repeated cyclically at 20° angular pitch, with an open state of 10° angular range in between.
FIG. 10
is a waveform chart of three-phase rectangular wave signal; where, first phase output
101
represents output signal from lead out section
17
C, second phase output
102
represents output signal from lead out section
19
C and third phase output
103
represents output signal from lead out section
18
C. Overall output
104
of the rotary encoder, which is an integration of the three-phase rectangular signals, exhibits rectangular waveform of 20° angular pitch. Output
104
is delivered continuously via terminals
8
connected with respective lead out sections
16
E,
17
C,
19
C and
18
C.
The three-phase rectangular wave signal is generated likewise, even when operation shaft
1
is revolved in the reverse revolving direction, viz. when it is revolved anti-clockwise.
As described above, in the rotary encoder of the present embodiment, a plurality of slider
11
's movable contact points
12
A-
12
C disposed on a certain circle of specific radius are driven by revolution of operation shaft
1
to make a sliding motion on contact point pattern
14
, which is disposed in a circular arrangement on contact-point board
13
. Thus, the rotary encoder can be implemented in a compact shape of small outer diameter.
By providing signal pattern
15
in the above-described arrangement, a three-phase rectangular wave signal can be generated continuously between three fixed contact points
17
-
19
of signal pattern
15
and common pattern
16
at a 20° pitch. The rectangular wave signal is outputted between lead out sections
17
C-
19
C and lead out section
16
E.
Width of each of conductive layers of fixed contact points
17
-
19
is smaller than ⅓ of 60°, which angle 60° being the angular pitch between the two conductive layers
17
A and
17
B, the two conductive layers
18
A and
18
B, and the two conductive layers
19
A and
19
B in respective fixed contact points
17
-
19
. As the result, a first phase, a second phase and a third phase rectangular wave signals can be outputted as independent signals. When the rotary encoder is used in an electronic apparatus, microcomputer-related circuits can be structured simply and the signal processing becomes easy; furthermore, power consumption for the signal processing can be made smaller.
In the above-described 18-signal type rotary encoder which generates three-phase rectangular wave signal at 20° pitch, such other signal patterns
15
having different angular pitch arrangement as illustrated in
FIG. 11
,
FIG. 12
may be used instead on contact-point board
13
. Fixed contact points
17
,
18
and
19
of signal pattern
15
in the foregoing descriptions are disposed on the same sliding circle as movable contact points
12
A-
12
C of slider
11
, at angular pitches 160° for one place and 100° for two places, as illustrated in FIG.
3
. Whereas in FIG.
11
and
FIG. 12
, each of the angular pitches of fixed contact points
17
,
18
and
19
is one of 80°, 140° and 200°. The angular pitches in the above configuration are smaller, or larger, than the angular interval 120° between movable contact points
12
A,
12
B,
12
C, or a multiple of it, by output pitch 20° of rectangular wave signal, or its double, 40°. Any one of the above angular pitches is larger than the one angular width 70° of fixed contact points
17
,
18
and
19
. The sum of the three angular pitches makes 360°.
Also in these pattern arrangements, conductive layers
16
A,
16
B,
16
C,
16
D and
16
F of common pattern
16
are disposed in the places where none of conductive layers
17
A-
19
B of fixed contact points
17
-
19
is disposed. Namely, they are disposed in places formed between the two conductive layers
17
A and
17
B of fixed contact point
17
, between the two conductive layers
18
A and
18
B of fixed contact point
18
, or between the two conductive layers
19
A and
19
B of fixed contact point
19
, or places between fixed contact points
17
-
19
at a certain specific angular position. These conductive layers are connected with common lead out section
16
E. These structures also implement compact rotary encoders that generate the same output.
(Embodiment 2)
The basic structure of a rotary encoder in accordance with a second exemplary embodiment of the present invention remains the same as that of the embodiment 1 shown in FIG.
1
. In the rotary encoder in the present embodiment has slider
21
in place of slider
11
, contact-point board
23
in place of contact-point board
13
, contact point pattern
24
in place of contact point pattern
14
, and movable contact points
22
A-
22
E in place of movable contact points
12
A-
12
C. Descriptions relevant to
FIG. 1
are identical to those made earlier in embodiment 1; so, they are eliminated here.
The rotary encoder in embodiment 2 is a 30-signal type that outputs three-phase rectangular wave signal at 12° pitch or 30 signals per 360° continuously.
FIG. 13
shows a plan view of a slider used in the rotary encoder in accordance with the present embodiment.
FIG. 14
is a conceptual drawing of contact point pattern on the contact-point board.
As shown in
FIG. 13
, slider
21
is provided with five elastic movable contact points
22
A-
22
E at an interval of 72° on a circle at a certain radius from the revolution center. The interval of movable contact points
22
A-
22
E is 6 times as large as the output pitch 12° of rectangular wave signal. Each of movable contact points
22
A-
22
E is adopted to make contact with the upper surface of contact-point board
23
.
As to the number of contact tips at each of movable contact points
22
A-
22
E, it remains the same as in embodiment 1. As shown in
FIG. 14
, contact-point board
23
is provided on the surface with contact point pattern
24
consisting of signal pattern
25
and common pattern
26
, in the same way as in embodiment 1. Namely, signal pattern
25
consisting of fixed contact points
27
,
28
and
29
is disposed on a circle of the same radius as movable contact points
22
A-
22
E. Fixed contact point
27
is formed of two conductive layers
27
A and
27
B of the same angular width 6° disposed in a radial arrangement, which share common lead out section
27
C. Conductive layers
27
A,
27
B are disposed at an angular pitch 36°, which angle being three times as large as the output pitch 12° of rectangular wave signal. Fixed contact points
28
and
29
are also formed to the identical structure; having a lead out section
28
C and a lead out section
29
C, and two conductive layers
28
A,
28
B conductive layers
29
A,
29
B, respectively.
Angular pitch of fixed contact points
27
and
28
is 60°, which pitch being smaller than angular interval 72° of movable contact points
22
A-
22
E of slider
21
by output pitch 12° of rectangular wave signal. Angular pitch of fixed contact points
28
and
29
is 132°, which pitch being smaller than twice the angular interval 72° of movable contact points
22
A-
22
E of slider
21
by output pitch 12° of rectangular wave signal. Angular pitch of fixed contact points
29
and
27
is 168°, which pitch being larger than twice the angular interval 72° of movable contact points
22
A-
22
E of slider
21
by twice the output pitch 12° of rectangular wave signal. Any one of the pitches is larger than one angular width 42° of fixed contact points
27
-
29
.
In the space between fixed contact points
29
and
27
, fan-shape conductive layer
26
A of common pattern
26
is provided for an angular range 114°, which conductive layer having dedicated lead out section
26
C and being insulated from signal pattern
25
. Conductive layer
26
A is disposed on contact-point board
23
along the sliding circle of the same radius as movable contact points
22
A-
22
E of slider
21
in the region where signal pattern
25
isn't disposed.
Now in the following, various states of coupling between contact point pattern
24
of contact-point board
23
and movable contact points
22
A-
22
E of slider
21
are described referring to FIG.
14
through FIG.
18
.
As shown in
FIG. 15
, in the normal state where operation shaft
1
is not revolved, clicking spring
9
is in engaged with a notch provided on the upper surface of holding portion
1
A, and slider
21
is having contact with common pattern
26
. However, slider
21
is making no contact with any of fixed contact points
27
-
29
, or it is standing still in open state. This state remains the same as in embodiment 1. Namely, only movable contact point
22
E is staying on conductive layer
26
A, but the remaining movable contact points
22
A-
22
D are making no contact with any one of fixed contact points
27
-
29
.
When operation shaft
1
is revolved, starting from the above-described open state, slider
21
makes clockwise sliding motion along contact point pattern
24
. The shifting state of contact is shown in conceptual drawings, FIG.
16
through FIG.
18
.
Starting from the state as shown in
FIG. 15
, when slider
21
is revolved clockwise, it shifts to FIG.
16
. Namely, after slider
21
is revolved clockwise for approximately 3°, movable contact point
22
A makes contact with conductive layer
27
A by an approximate angular range 6°. During the moment, movable contact point
22
E is having contact with conductive layer
26
A, and lead out section
26
C and lead out section
27
C are in conduction state to each other.
When slider
21
is revolved further, movable contact point
22
D gets in contact with conductive layer
29
B of fixed contact point
29
, as shown in
FIG. 17
, after having an open state for approximately 6° angular range. During the moment, movable contact points
22
E is keeping contact with conductive layer
26
A. Thus, lead out section
26
C and lead out section
29
C are in conduction state to each other.
When slider
21
is revolved further, movable contact point
22
B gets in contact with conductive layer
28
B of fixed contact point
28
, as shown in
FIG. 18
, after having an open state for approximately 6° angular range. Also during the moment, movable contact point
22
E is keeping contact with conductive layer
26
A. Thus, lead out section
26
C and lead out section
28
C are in conduction state to each other.
As described above, the clockwise revolution of slider
21
brings respective lead out sections
27
C,
29
C and
28
C into conduction state with lead out section
26
C one after the other in the order, for an angular pitch of 12° with an open state of angular range 6° in between. The cycle repeats.
FIG. 19
is a waveform chart of three-phase rectangular wave signal, where first phase output
201
represents output signal from lead out section
27
C, second phase output
202
represents output signal from lead out section
29
C and third phase output
203
represents output signal from lead out section
28
C. Overall output
204
of the rotary encoder, which is an integration of the three-phase rectangular signals, exhibits a rectangular wave of 12° pitch. Output
204
is delivered continuously via terminal
8
connected with respective lead out sections
26
C,
27
C,
29
C and
28
C. The three-phase rectangular wave signal is generated likewise even when operation shaft
1
is revolved in the reverse revolving direction, viz. when slider
21
is revolved anti-clockwise.
As described above, in the rotary encoder of the present embodiment, a plurality of slider
21
's movable contact points
22
A-
22
E disposed on a certain circle of specific radius are driven by revolution of operation shaft
1
to make a sliding motion on contact point pattern
24
, which is disposed in a circular arrangement on contact-point board
23
. Thus, the rotary encoder can be implemented in a compact shape of small outer diameter.
By providing signal pattern
25
in the above-described arrangement, a three-phase rectangular wave signal can be generated continuously between three fixed contact points
27
-
29
of signal pattern
25
and common pattern
26
at a 12° pitch. The rectangular wave signal is outputted between lead out sections
27
C-
29
C and lead out section
26
E.
Also in the rotary encoder in the present embodiment, the first phase, the second phase and the third phase rectangular wave signals can be outputted as independent signals, like in embodiment 1. When the rotary encoder is used in an electronic apparatus, microcomputer-related circuits can be structured simply and the signal processing becomes easy; furthermore, power consumption for the signal processing can be made smaller.
In the above-described 30-signal type rotary encoder which generates three-phase rectangular wave signal at 12° pitch, such other signal patterns
25
having different angular pitch arrangement as illustrated in
FIG. 20
,
FIG. 21
may be used instead on contact-point board
23
. Fixed contact points
27
,
28
and
29
of signal pattern
25
in the foregoing descriptions are disposed on the same sliding circle as movable contact points
22
A-
22
E of slider
21
, at angular pitches 60°, 132° and 168°, as illustrated in FIG.
14
. Whereas in FIG.
20
and
FIG. 21
, each of the angular pitches of fixed contact points
27
-
29
is one of 60°, 240°, 96° and 132°. The angular pitches in the above configuration are smaller, or larger, than the angular interval 72° between movable contact points
22
A-
22
C, or a multiple of it, by output pitch 12° of rectangular wave signal, or its double, 24°. Any one of the above angular pitches is larger than the one angular width 42° of fixed contact points
27
-
29
. The sum of the three angular pitches makes 360°.
Also in these pattern arrangements, conductive layers
26
A,
26
B and
26
D of common pattern
26
are disposed in the places where none of conductive layers
27
A-
29
B of fixed contact points
27
-
29
is disposed. Namely, they are disposed in places formed between fixed contact points
27
-
29
, between the two conductive layers
27
A and
27
B of fixed contact point
27
, between the two conductive layers
28
A and
28
B of fixed contact point
28
, or between the two conductive layers
29
A and
29
B of fixed contact point
29
, at a certain specific angular position. These conductive layers are connected with common lead out section
26
C. These structures also implement compact rotary encoders that generate the same output.
In the above exemplary embodiments 1 and 2, descriptions have been made on rotary encoders which generate three-phase rectangular wave signals for 18 signals per 360°, and 30 signals per 360°. Other types of rotary encoders generating 36 signals, 45 signals, etc. can also be implemented through the same concept.
Claims
- 1. A rotary encoder outputting rectangular wave signals comprisinga contact-point board having a conductive signal pattern and a common pattern; and a slider supported to be revolvable with respect to said contact-point board, which slider having a plurality of movable contact points disposed on a circle of a certain radius from a revolution center at an angular interval six times as large as an output pitch of the rectangular wave signal; wherein said signal pattern consists of three fixed contact points, each having two conductive layers of radial shape with the same width, electrically connected to each other, disposed along sliding circle of said movable contact points at an angular pitch three times as large as the output pitch of the rectangular wave signal; angular pitch of said three fixed contact points is different from one of angular interval of said movable contact points, and a multiple of the angular interval of said movable contact points, by one of the output pitch of the rectangular wave signal, and twice of the output pitch of the rectangular wave signal, and larger than any one angular width of said three fixed contact points; and said common pattern is disposed insulated from said signal pattern on said contact-point board along sliding circle of said movable contact points, so that, at the time when either one of said movable contact points of said slider is having contact with either one of said three fixed contact points, it makes contact with remaining one of said movable contact points.
- 2. The rotary encoder of claim 1, whereinrevolution of said slider generates three-phase rectangular wave signal continuously between said three fixed contact points and said common pattern at an equal pitch.
- 3. The rotary encoder of claim 1, whereinangular width of said conductive layer of radial shape is less than ⅓ of angular pitch of said two conductive layers of radial shape having electrical conduction to each other.
- 4. The rotary encoder of claim 1, whereinsaid movable contact point is provided with a plurality of contact tips which make contact with said contact-point board.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2002-183904 |
Jun 2002 |
JP |
|
US Referenced Citations (8)
Foreign Referenced Citations (2)
Number |
Date |
Country |
3-26021 |
Mar 1991 |
JP |
6-94476 |
Apr 1994 |
JP |