Information
-
Patent Grant
-
6275173
-
Patent Number
6,275,173
-
Date Filed
Thursday, March 2, 200024 years ago
-
Date Issued
Tuesday, August 14, 200122 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 341 13
- 341 14
- 341 15
- 250 23113
- 250 23114
- 250 23116
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International Classifications
-
Abstract
A rotary encoder able to produce a first output signal and a second output signal. The rotary encoder of this invention includes a rotary wheel supported by a frame. An elastic means disposed on the frame provides elastic force to the inside wall of the rotary wheel. A plate is mounted on and rotates with the rotary wheel, and there are a plurality of apertures arranged at a predetermined pitch circularly around an axis of rotation of the plate. An axial rod extends perpendicularly from the center of the plate. Pressure applied to the rotary wheel causes the elastic means to compress and shifts the axis of the wheel and plate such that axial rod contacts a switch and produces the first output signal. A second output signal is produced by a light transmitter located on one side of the plate and a light receiver located on the other side of the plate, wherein the light transmitter and light receiver are arranged so that light passes through an aperture in the plate and is received by the light receiver when rotation of the plate is such that the aperture and the light transmitter are aligned, and light is blocked by the plate when rotation of the plate is such that an aperture and the light transmitter are not aligned.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotary encoder able to produce two output signals. More particularly, the present invention relates to a single rotary encoder that can be used as both a shuttle switch and a mode switch.
2. Description of the Related Art
FIGS. 1 and 2
illustrate two rotary encoders according to the prior art. In
FIG. 1
, a light receiving plate
24
and a light encoding plate
23
are engaged to the cylinder of a fixing base
27
so as to be rotatable about a shaft
11
, and an output signal is produced by the rotation of fixing base
27
. Similarly, in
FIG. 2
a light emitting diode
20
is supported by support
30
so as to transmit light through holes in plate
1
to be received by a light receiver beneath the plate
1
(not shown), by which means a pulse signal is generated by alternating the receiving and not receiving of light by the light receiver. These types of rotary encoder can be applied as a shuttle switch to control a parameter of an electronic device, for example the brightness of a computer monitor.
However, in practical application, an electronic device usually has a plurality of parameters that the user needs to control. For example, a computer monitor might have the parameters brightness, sharpness, and color. To allow control of these three parameters, the monitor would require three shuttle switches. As an alternative, a monitor could include a mode switch for each of the parameters and a single shuttle switch. If the user desired to adjust the contrast, he could press the mode switch corresponding to contrast and then use the shuttle switch for adjusting the value.
In both of these examples, a plurality of switches are required to control a plurality of parameters. This increases the cost of the device.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a single rotary encoder that can provide two output signals and operate as both a shuttle switch and a mode switch.
To achieve the above object, this invention provides a rotary encoder able to produce a first output signal and a second output signal comprising: a rotary wheel having an inside wall; a frame for supporting the rotary wheel; an elastic means disposed on the frame for providing elastic force to the inside wall of the rotary wheel; a plate mounted on and rotating with the rotary wheel, the plate being provided with a plurality of apertures arranged at a predetermined pitch circularly around an axis of rotation of the plate; an axial rod having a distal portion and extending perpendicularly from the plate; a switch disposed in proximity to the distal portion of the axial rod, wherein pressure applied to the rotary wheel will cause the elastic means to compress and shift the axis of the wheel and plate such that axial rod contacts the switch and produces the first output signal; a light transmitter provided on one side of the plate; and a light receiver provided on the other side of the plate; wherein the light transmitter and light receiver are arranged so that light from the light transmitter travels through an aperture in the plate and is received by the light receiver when rotation of the plate is such that the aperture and the light transmitter are aligned, and light from the light transmitter is blocked by the plate when rotation of the plate is such that an aperture and the light transmitter are not aligned; wherein the receiving or not receiving of light by the light receiver produces the second output signal. The elastic means may comprise a spring with a rotating means disposed between the spring and the inner wall of the rotary wheel. The rotating means could be a roller.
BRIEF DESCRIPTION OF DRAWINGS
The following detailed description, given by way of examples and not intended to limit the invention to the embodiments described herein, will best be understood in conjunction with the accompanying drawings, in which:
FIG. 1
illustrates a rotary encoder of the prior art;
FIG. 2
illustrates another rotary encoder of the prior art;
FIGS. 3A and 3B
are exploded views of the rotary encoder according to one embodiment of the present invention from a first direction and second direction, respectively;
FIGS. 4A and 4B
illustrate the application of the rotary encoder of the present invention to a monitor;
FIG. 5
illustrates the light receiver of the rotary encoder of the present invention according to a second embodiment;
FIGS. 6A-6C
illustrate alternative embodiments for the structure of the frame of the rotary encoder of the present invention;
FIG. 7A
illustrates the alignment of an aperture and the light transmitter and receiver in the rotary encoder of the present invention; and
FIG. 7B
illustrates a preferred shape for an aperture.
DETAILED DESCRIPTION OF THE INVENTION
Please refer to
FIGS. 3A and 3B
. In an embodiment of the present invention, a rotary wheel
103
comprises an outer surface
103
a
and an inner surface
103
b
. The inner surface
103
b
can be provided with ridges
103
f
. A plate
103
c
is mounted at one end of the rotary wheel
103
, a plurality of apertures
103
e
being arranged at a predetermined pitch circularly around the axis of rotation of the plate
103
c
. An axial rod
103
d
extends perpendicularly from the center of the plate
103
c.
A tire
102
can be provided on the outer surface
103
a
of the rotary wheel
103
. The tire
102
can be provided with indentations
102
a
for easy manipulation by the user.
The rotary wheel
103
is supported by a frame comprising a proximal portion
104
, a distal portion
101
, and a central portion
112
. The proximal portion
104
has a plurality of hooks
104
a
for providing a firm grip to circuit board
108
. Also provided are snap
104
c
′ on sidewall
104
c
and snap
104
b
′ on sidewall
104
b
for snapping to corresponding grooves in distal portion
101
. In the rearwall
104
d
is provided a well
104
e.
The distal portion
101
is also provided with a well
101
b
, in which a slot
101
c
is formed to allow axial rod
103
d
to pass through.
The central portion
112
shares a wall with the well
104
e
of the proximal portion
104
. Both the upper walls
112
c
and the lower walls
112
d
of the central portion
112
are substantially arced in shape; thus, when the inner surface
103
b
of the rotary wheel
103
contacts with either the upper walls
112
c
or the lower walls
102
d
, its rotation is not impeded. A groove
112
e
is formed in the lower walls
112
d
so that well
104
e
is communicated by line of sight to well
101
b.
A spring
105
is disposed in the well
112
a
of the central portion
112
. Over the spring is provided a support
106
and a roller
107
. The support
106
has a well
106
a
and grooves
106
b
in the upper surface
106
d
of sidewalls
106
c
. The grooves
106
b
receive the rods
107
a
and
107
b
of roller
107
when it is cradled in well
106
a
. The upper surfaces
106
d
are also substantially arced in shape.
On the circuit board
108
are disposed light transmitter
110
, light receiver
109
and switch
111
with a metal spring leaf
111
a.
The assembly of the rotary encoder of this embodiment will now be described. First, the tire
102
is disposed on the rotary wheel
103
. The open end of the rotary wheel
103
is then placed over the central portion
112
such that the roller
107
is in contact with and providing elastic pressure to the inside wall
103
b
of the rotary wheel
103
. The proximal portion
104
and the distal portion
101
of the frame are then snapped together by snaps
104
b
′ and
104
c
′ and the corresponding grooves in distal portion
101
. Note the end of the axial rod
103
d
passes through the slot
101
c
and extends therefrom. The apparatus is then locked onto circuit board
108
by means of hooks
104
a
such that light receiver
109
is received in well
101
b
and light transmitter
110
is received in well
104
e
. Furthermore, the end of the axial rod
103
d
passing through the slot
101
c
is in the proximity of the spring leaf
111
a
of the switch
111
.
The operation of the rotary encoder of this embodiment will now be described. The rotary encoder of this invention produces two output signals. The first output signal produced by contact of the end of the axial rod
103
d
and the spring leaf
111
a
of the switch
111
. This contact is achieved as follows. When no external pressure is being applied to the rotary wheel
103
, the spring
105
provides an elastic pressure upon the support
106
and the roller
107
to the inside surface
103
b
of the rotary wheel
103
. In this situation, the inner surface
103
b
is lifted away from the upper walls
112
c
of the central portion
112
, and the axial rod
103
d
is in contact with the upper portion
101
C
′ in slot
101
c
, which acts as a stop to the movement of the rotary wheel
103
in the direction of the elastic pressure. Furthermore, the roller
107
in contact with the inner surface
103
b
of the rotary wheel
103
also allows the free rotation of the rotary wheel
103
. When in this position, the axial rod is
103
d
passes through slot
101
c
and is in the proximity of spring leaf
111
a.
When external pressure is applied to the rotary wheel
103
, the spring
105
is compressed. In this situation, the axial rod
103
d
is pushed to the lower portion
101
C″ in slot
101
C, which acts as a stop to the movement of the rotary wheel
103
in the direction of the external pressure, while the opposite side of the inner surface
103
b
is pressed away from the lower walls
112
d
of the central portion
112
. Thus, the axis of the rotary wheel
103
and the plate
103
c
mounted thereon shifts in the direction of the external pressure, thereby causing the axial rod
103
d
to shift position in slot
101
c
. This shift causes the axial rod
103
d
to come contact with the spring leaf
111
a
and urge it to contact a contact point on the switch
111
and output the first signal along path
111
b.
Note that when the spring
105
is compressed by external pressure, the substantially arced shape of the upper walls
112
c
allows the rotary wheel
103
to rotate even when in contact with the upper walls
112
c
. Furthermore, the roller
107
in contact with the inner surface
103
b
of the rotary wheel
103
still allows the free rotation of the rotary wheel
103
when external pressure is applied.
The second output signal is produced by the interaction of the light receiver
109
, the light transmitter
110
, and the rotation of the apertures
103
e
in the plate
103
c
. Referring to
FIG. 7A
, the light transmitter
110
and light receiver
109
are arranged on the circuit board
108
so that light from the light transmitter
110
travels through an aperture
103
e
in the plate
103
c
and through the groove
112
e
in central portion
112
to be received by the light receiver
109
when the position of the plate
103
c
is such that the aperture
103
e
and the light transmitter
110
are aligned. Rotation of the plate
103
c
will shift the position of the apertures
103
e
so that an aperture
103
e
and the light transmitter
110
are not aligned, and therefore light from the light transmitter
110
is blocked by the plate
103
c
. Further rotation of the plate
103
c
will further shift the position of the apertures
103
e
so that an aperture
103
e
and the light transmitter
110
are again aligned (as in FIG.
7
A), and therefore light from the light transmitter
110
may again be received by light receiver
109
. The receiving or not receiving of light by the light receiver
109
produces the second output signal in the form of a pulse generated along path
109
b
each time the rotary wheel
103
is rotated a number of degrees corresponding to the pitch of the apertures.
If provided, ridges
103
f
can control the ease of this rotation by providing extra friction to the inner surface
103
b.
Furthermore, the apertures
103
e
′ can be substantially trapezoidal in shape, as shown in FIG.
7
B. Another embodiment of the rotary encoder will now be described. When no external pressure is being applied to the rotary wheel
103
, the spring
105
provides an elastic pressure upon the support
106
and the roller
107
to the inside surface
103
b
of the rotary wheel
103
. In this situation, the light transmitter
110
and light receiver
109
are arranged on the circuit board
108
so that light from the light transmitter
110
travels through the groove
112
e
in central portion
112
and through the aperture
103
e
′ in the plate
103
c
to be received fully by the light receiver
109
when the position of the plate
103
c
is such that the aperture
103
e
′ and the light transmitter
110
are aligned. When the spring
105
is compressed by external pressure, the aperture
103
e
′ is moved in the direction of the external pressure so that light from the light transmitter
110
travels through the aperture
103
e
′ to be decreased. Then the changing of light received by the light receiver
109
produces the first signal.
The rotary encoder of this invention could be used to control the parameters of an electronic device such as a computer monitor.
FIG. 4A
illustrates the positioning of a rotary encoder
151
on the front face
152
of a monitor
150
.
FIG. 4B
illustrates the positioning of a rotary encoder
151
on the side
154
of a monitor
150
. In operation, an OSD (On Screen Display) could be activated by pressing the rotary encoder
151
to produce a first output signal. The OSD, as controlled by the computer microprocessor, could provide a menu of parameters to be controlled. By repeatedly pressing the rotary encoder
151
, the user could scroll through the menu until reaching the parameter he would like to adjust, for example brightness. Then the user could rotate the rotary encoder
102
to provide a second output signal and change the value of the selected parameter.
FIG. 5
illustrates another embodiment of the light receiver
109
in the optical encoder of this invention. In this embodiment, there are two optical units
109
a
and
109
b
for receiving light transmitted from light transmitter
110
. When an aperture
103
e
is unaligned with the light receiver
109
, neither optical units
109
a
and
109
b
receive light transmitted from light transmitter
110
. If the plate
103
c
is rotated in a first direction, then the optical unit
109
a
will be the first to receive light, followed by a fully aligned state in which both optical units
109
a
and
109
b
receive light. If the plate
103
c
is rotated in a second direction, then the optical unit
109
b
will be the first to receive light, followed by a fully aligned state in which both optical units
109
a
and
109
b
receive light. Thus, the order of pulses triggered by the detection of light by optical units
109
a
and
109
b
can be used to determine the direction of rotation of the rotary wheel
103
. In the above described practical application of the rotary encoder of this invention to a monitor, this embodiment would allow the user to control a parameter, for example brightness, by either increasing or decreasing its value.
In the above described embodiments, the structure of the frame supporting the rotary wheel
103
comprises a U-shaped proximal portion
104
to which the central portion
112
is attached and a straight shaped distal portion
101
, as shown in FIG.
6
A. However, other embodiments of the frame structure will be apparent to those skilled in the art. For example,
FIG. 6B
shows a frame structure in which proximal portion
104
-
1
and distal portion
101
-
1
are both L-shaped, while
FIG. 6C
shows a frame structure in which proximal portion
104
-
2
is straight shaped and distal portion
101
-
2
is U-shaped.
While the invention has been described with reference to various illustrative embodiments, the description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to those person skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as may fall within the scope of the invention defined by the following claims and their equivalents.
Claims
- 1. A rotary encoder for producing a first output signal and a second output signal comprising:a rotary wheel having an inside wall; a frame for supporting the rotary wheel; an elastic means disposed on the frame for providing elastic force to the inside wall of the rotary wheel; a plate mounted on and rotating with the rotary wheel, the plate being provided with a plurality of apertures arranged at a predetermined pitch circularly around an axis of rotation of the plate; an axial rod having a distal portion and extending perpendicularly from the plate; a switch disposed in proximity to the distal portion of the axial rod, wherein pressure applied to the rotary wheel will cause the elastic means to compress and shift the axis of the wheel and plate such that axial rod contacts the switch and produces the first output signal; a light transmitter provided on one side of the plate; and a light receiver provided on the other side of the plate; wherein the light transmitter and light receiver are arranged so that light from the light transmitter travels through an aperture in the plate and is received by the light receiver when rotation of the plate is such that the aperture and the light transmitter are aligned, and light from the light transmitter is blocked by the plate when rotation of the plate is such that an aperture and the light transmitter are not aligned; wherein the receiving or not receiving of light by the light receiver produces the second output signal.
- 2. The rotary encoder as claimed in claim 1, wherein the elastic means comprises a spring.
- 3. The rotary encoder as claimed in claim 2, wherein a rotating means is disposed between the spring and the inner wall of the rotary wheel.
- 4. The rotary encoder as claimed in claim 3, wherein the rotating means is a roller.
- 5. The rotary encoder as claimed in claim 1, wherein the inside wall of the rotary wheel is ridged.
- 6. The rotary encoder as claimed in claim 1, wherein the apertures are substantially trapezoidal in shape.
- 7. The rotary encoder as claimed in claim 1, wherein the switch is a limit switch comprising:a spring leaf made of metal; and a switch body engaged with the spring leaf and having a contact point on the surface, wherein pressure applied to the rotary wheel will cause the elastic means to compress and shift the axis of the wheel and plate such that axial rod contacts the spring leaf and urges it into contact with the contact point, thus producing the first output signal.
- 8. The rotary encoder as claimed in claim 1, wherein a tire is disposed on the outside of the rotary wheel.
- 9. The rotary encoder as claimed in claim 8, wherein the tire is provided with indentations for easy manipulation by a user.
- 10. The rotary encoder as claimed in claim 1, wherein the light receiver comprises two optical units for detecting light.
- 11. A rotary encoder for producing a first output signal and a second output signal comprising:a rotary wheel having an inside wall; a frame for supporting the rotary wheel; an elastic means disposed on the frame for providing elastic force to the inside wall of the rotary wheel; a plate mounted on and rotating with the rotary wheel, the plate being provided with a plurality of apertures arranged at a predetermined pitch circularly around an axis of rotation of the plate; a light transmitter provided on one side of the plate; and a light receiver provided on the other side of the plate; wherein the light transmitter and light receiver are arranged so that light from the light transmitter travels through an aperture in the plate and is received by the light receiver when rotation of the plate is such that the aperture and the light transmitter are aligned, and light from the light transmitter is blocked by the plate when rotation of the plate is such that the aperture and the light transmitter are not aligned; wherein the receiving or not receiving of light by the light receiver produces the second output signal; wherein when pressure applied to the rotary wheel will cause the elastic means to compress and shift the axis of the wheel and plate such that the aperture is moved in the direction of the pressure so that light changed by the aperture; wherein the receiving of light by the light receiver produces the first output signal.
- 12. The rotary encoder as claimed in claim 11, wherein the apertures are substantially trapezoidal in shape.
- 13. The rotary encoder as claimed in claim 12, wherein the aperture is moved in the direction of the pressure so that light decreased by the aperture.
Priority Claims (1)
Number |
Date |
Country |
Kind |
088103502 |
Mar 1999 |
TW |
|
US Referenced Citations (2)