U.S. patent application number 13/240149 was filed with the patent office on 2012-01-12 for pointing device.
This patent application is currently assigned to Asahi Kasei EMD Corporation. Invention is credited to Toshinori TAKATSUKA.
Application Number | 20120007803 13/240149 |
Document ID | / |
Family ID | 32767275 |
Filed Date | 2012-01-12 |
United States Patent
Application |
20120007803 |
Kind Code |
A1 |
TAKATSUKA; Toshinori |
January 12, 2012 |
POINTING DEVICE
Abstract
A pointing device is provided which can reduce its size and
height, reduce leakage magnetic flux density to the outside.
Magnetic sensors are disposed symmetrically two by two on X and Y
axes on a printed circuit board. A silicone resin is placed on the
printed circuit board, and an internally and externally unipolarly
magnetized ring-like magnet is placed near the center of the
magnetic sensors. The printed circuit board and silicone resin are
not bonded. The silicone resin is easily deformed by applying
external force, and returns to its initial state without the
external force as soon as the external force is removed. The
ring-like magnet is configured to move approximately in parallel to
the surface of the printed circuit board. The variations in the
ambient magnetic flux density produced by the movement of the
ring-like magnet are detected by the magnetic sensors.
Inventors: |
TAKATSUKA; Toshinori;
(Fuji-Shi, JP) |
Assignee: |
Asahi Kasei EMD Corporation
|
Family ID: |
32767275 |
Appl. No.: |
13/240149 |
Filed: |
September 22, 2011 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10542643 |
Jul 19, 2005 |
8054291 |
|
|
PCT/JP2004/000272 |
Jan 16, 2004 |
|
|
|
13240149 |
|
|
|
|
Current U.S.
Class: |
345/157 |
Current CPC
Class: |
G06F 3/0354 20130101;
G06F 3/0338 20130101 |
Class at
Publication: |
345/157 |
International
Class: |
G06F 3/033 20060101
G06F003/033 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 20, 2003 |
JP |
2003-011291 |
Claims
1-18. (canceled)
19. A pointing device comprising: a ring-like magnet that is
movably supported in a plane, and is magnetized such that said
ring-like magnet comprises inner and outer ring sections of north
and south magnetization that are both in said plane along a radius
of said ring-like magnet; and a plurality of magnetic sensors for
detecting magnetic flux density produced by said ring-like magnet
in a direction parallel to said plane are placed outside said
ring-like magnet, wherein said magnetic sensors are disposed
symmetrically from each other to said ring-like magnet, said
magnetic sensors are positioned to detect variations in the
magnetic flux density in the direction parallel to said plane, the
variations being caused by movement of said ring-like magnet in a
direction parallel to said plane.
20. The pointing device as claimed in claim 19, further comprising
a printed circuit board on which a resin layer with elastic
deformation is provided, wherein said ring-like magnet is fixed to
said resin layer, and said ring-like magnet is movably supported in
parallel to said printed circuit board, said magnetic sensors are
placed on said printed circuit board.
21. The pointing device as claimed in claim 19, wherein said
magnetic sensors are magnetic sensors utilizing Hall effect, and
the output signals are proportional to the magnetic flux
density.
22. The pointing device as claimed in claim 19, wherein said
magnetic sensors are magnetic sensors utilizing magneto-resistive
effect.
23. The pointing device as claimed in claim 19, further comprising
an origin returning means for returning said ring-like magnet to
the origin using magnetic force generated by said ring-like
magnet.
24. The pointing device as claimed in claim 19, wherein said
magnetic sensors are disposed and faced to one of the outer ring
sections of said ring-like magnet.
25. The pointing device as claimed in claim 20, wherein said resin
layer and said printed circuit board have their opposing faces not
bonded to each other.
26. The pointing device as claimed in claim 20, wherein said resin
layer is an elastic sheet.
27. The pointing device as claimed in claim 20, wherein said resin
layer is a silicone resin.
28. The pointing device as claimed in claim 20, further comprising
a switch on the resin layer side of said printed circuit board and
at about the center of said ring-like magnet.
29. The pointing device as claimed in claim 28, further comprising
a projection for depressing said switch at a portion facing said
switch on said resin layer.
30. The pointing device as claimed in claim 21, wherein said
magnetic sensors utilizing the Hall effect are disposed on the
resin layer side of said printed circuit board to detect the
magnetic flux density in a direction parallel to the surface of
said printed circuit board.
31. The pointing device as claimed in claim 21, wherein said
magnetic sensors utilizing the Hall effect are magnetic sensors
with a single output terminal.
32. The pointing device as claimed in claim 22, wherein said
magnetic sensors utilizing the magneto-resistive effect are
semiconductor magneto-resistive elements which are disposed on the
resin layer side of said printed circuit board to detect the
magnetic flux density in a direction parallel to the surface of
said printed circuit board.
33. The pointing device as claimed in claim 22, wherein said
magnetic sensors utilizing the magneto-resistive effect are four
semiconductor magneto-resistive elements disposed symmetrically on
X and Y axes, which are two axes on a two dimensional plane of an
orthogonal system, wherein two magnetic sensors on the X axis are
electrically connected at a first connection point; and two
magnetic sensors on the Y axis are electrically connected at a
second connection point, and wherein said pointing device detects
variations in ambient magnetic flux density caused by movement of
said ring-like magnet using electric signals at the first and
second connection points.
34. An electronic device incorporating the pointing device as
defined in claim 19.
35. The pointing device as claimed in claim 19, wherein said
ring-type magnet is magnetized at M sets of north-south poles,
where M=K.times.I, K equals the number of magnetic sensors, and I
is an integer equal to or greater than one.
36. A pointing device comprising: a ring-like magnet that is
movably supported in a plane, and is internally and externally
magnetized along said ring in said plane; and a plurality of
magnetic sensors positioned a distance from a location half way
between an upper and lower surface of said ring-like magnet to a
location half way between an upper and lower surface of one of said
magnetic sensors is within 0 and 0.75 mm in vertical direction to
said plane, wherein said magnetic sensors are positioned to detect
variations in the magnetic flux density in the direction parallel
to said plane, the variations being caused by movement of said
ring-like magnet.
37. The pointing device as claimed in claim 36, wherein said
magnetic sensors are magnetic sensors utilizing magneto-resistive
effect.
38. The pointing device as claimed in claim 37, wherein said
magnetic sensors utilizing the magneto-resistive effect are four
semiconductor magneto-resistive elements disposed symmetrically on
X and Y axes, which are two axes on a two dimensional plane of an
orthogonal system, wherein two magnet sensors on the X axis are
electrically connected at a first connection point; and two
magnetic sensors on the Y axis are electrically connected at a
second connection point, and wherein said pointing device detects
variations in ambient magnetic flux density caused by movement of
said ring-like magnet using electric signals at the first and
second connection points.
39. The pointing device as claimed in the claim 36, wherein said
ring-like magnet is internally and externally unipolarly
magnetized.
40. The pointing device as claimed in claim 36, wherein said
ring-like magnet is internally and externally magnetized in a
multipolar manner in the direction of its circumference, and said
magnetic sensors are faced to a magnetic pole of said ring-like
magnet magnetized in a multipolar manner.
41. The pointing device as claimed in claim 36, wherein said
magnetic sensors are disposed symmetrically on X and Y axes, which
are two axes on a two dimensional plane of an orthogonal system,
and said ring-like magnet is placed near said magnetic sensors.
42. The pointing device as claimed in claim 36, wherein said
magnetic sensors are magnetic sensors utilizing Hall effect, and
the output signals are proportional to the magnetic flux
density.
43. The pointing device as claimed in claim 42, wherein said
magnetic sensors utilizing the Hall effect are magnetic sensors
with a single output terminal.
44. The pointing device as claimed in claim 36, further comprising
an origin returning means for returning said ring-like magnet to
the origin using magnetic force generated by said ring-like
magnet.
45. The pointing device as claimed in claim 36, further comprising
a printed circuit board on which a resin layer with elastic
deformation is provided, a switch on the resin layer side of said
printed circuit board and at about the center of said ring-like
magnet, and a projection for depressing said switch at a portion
facing said switch on said resin layer.
46. The pointing device as claimed in claim 45, wherein said resin
layer and said printed circuit board have their opposing faces not
bonded to each other.
47. The pointing device as claimed in claim 45, wherein said resin
layer is an elastic sheet.
48. The pointing device as claimed in claim 45, wherein said resin
layer is a silicone resin.
49. An electronic device incorporating the pointing device as
defined in claim 36.
50. The pointing device as claimed in claim 25, wherein said
distance in the vertical direction is within 0 and 0.5 mm.
51. The pointing device as claimed in claim 25, wherein said
distance in the vertical distance is within 0 and 0.25 mm.
52. The pointing device as claimed in claim 25, wherein said sensor
portion is at a location halfway between an upper and lower surface
of one of said magnetic sensors.
Description
TECHNICAL FIELD
[0001] The present invention relates to a pointing device used as
an input means of a personal computer, mobile phone and the like,
and more particularly to a magnetic detection type pointing device
for carrying out coordinate detection or inputting vector
information by detecting ambient magnetic flux density variations
due to the movement of a magnet.
BACKGROUND ART
[0002] FIG. 1 is a block diagram showing a magnetic detector
circuit of a conventional magnetic detection type pointing device.
A detecting section 1 includes four magnetic sensors (such as Hall
elements, semiconductor magneto-resistive elements, thin-film
magneto-resistive elements and GC elements) 11, and the Hall
elements 11 are placed symmetrically two by two on the X and Y
axes. A magnet is placed near the center of the four Hall elements
11 symmetrically disposed on the X and Y axes. Because of the
variations in the magnetic flux density due to the movement of the
magnet, the output voltages of the Hall elements 11 vary.
[0003] Differential amplifiers 2 differentially amplify the outputs
of the Hall elements 11 on the X and Y axes, respectively. The
output is adjusted to zero when the magnetic flux density in the Z
direction is symmetry with respect to the origin O, that is, when
the magnetized direction of the magnet is in the vertical
direction. As the magnet moves, the differential amplifiers 2
produce outputs, and a detection control section 3 converts the
outputs (analog values) in the X coordinate value and Y coordinate
value, which are output through an output control section 4.
[0004] As a concrete example of a small pointing device used by a
mobile phone, a device is known which employs a scheme placing a
magnet on a key mat. Such devices based on the method enable
miniaturization among the currently proposed ideas (see Japanese
patent application laid-open No. 2002-150904, for example).
[0005] As a contact type pointing device, a device is common which
forms on a printed board two pairs of comb electrodes, and
depresses them via a conductive rubber from the top to vary the
current-passing state, thereby outputting coordinate values in
digital values.
[0006] However, in small mobile electronic equipment such as a
mobile phone, further reductions in size and height of the
components are required to satisfy mutually contradictory needs of
reducing the size and improving the function of the electronic
equipment in its entirety. In addition, further improvement in
operating feelings of the magnetic detection type pointing device
is expected.
[0007] Furthermore, as for the foregoing publication, since the
magnet is magnetized in the vertical direction, the magnetic flux
density that leaks out is large so that when a magnetic card is
brought close to it, a problem of losing the information of the
magnetic card is likely to occur.
[0008] Moreover, since the input is made by depressing the
conductive rubber in the contact type pointing device, degradation
of the conductive rubber involved in repetitive input and the like
is unavoidable, which presents a problem of reducing the life
[0009] The present invention is implemented to solve the foregoing
problems. Therefore it is an object of the present invention to
provide a pointing device that can reduce the size and height, and
provide a good operating feeling, and that has small external
leakage of the magnetic flux density, and has a long product
life.
DISCLOSURE OF THE INVENTION
[0010] To accomplish the object of the present invention, there is
provided a pointing device characterized by comprising a ring-like
magnet that is movably supported in parallel to a plane; and a
plurality of magnetic sensors for detecting magnetic flux density
produced by the ring-like magnet in a direction parallel to the
plane, wherein the magnetic sensors detect variations in the
magnetic flux density in the direction parallel to the plane, the
variations being caused by movement of the ring-like magnet.
[0011] The ring-like magnet is characterized by internally and
externally unipolarly magnetized.
[0012] The ring-like magnet is characterized by having at least one
of its internal wall and external wall magnetized in a multipolar
manner, and the magnetic sensors are characterized by facing to a
magnetic pole center of the ring-like magnet magnetized in a
multipolar manner.
[0013] The pointing device is characterized by further comprising a
printed circuit board on which a resin layer is provided, wherein
the ring-like magnet is fixed to the resin layer, and the magnetic
sensors are placed on the printed circuit board.
[0014] The resin layer and the printed circuit board are
characterized by having their opposing faces not bonded to each
other.
[0015] The resin layer is characterized by being an elastic
sheet.
[0016] The resin layer is characterized by being a silicone
resin.
[0017] The magnetic sensors are characterized by being disposed
symmetrically on X and Y axes, which are two axes on a two
dimensional plane of an orthogonal system, and the ring-like magnet
is characterized by being placed near the center of the magnetic
sensors.
[0018] The pointing device is characterized by further comprising a
switch on the resin layer side of the printed circuit board and at
about the center of the ring-like magnet.
[0019] The pointing device is characterized by further comprising a
projection for depressing the switch at a portion facing the switch
on the resin layer.
[0020] The magnetic sensors are characterized by being magnetic
sensors utilizing Hall effect, and outputting signals proportional
to the magnetic flux density.
[0021] The magnetic sensors utilizing the Hall effect are
characterized by being disposed on the resin layer side of the
printed circuit board to detect the magnetic flux density in a
direction parallel to the surface of the printed circuit board.
[0022] The magnetic sensors utilizing the Hall effect are
characterized by being magnetic sensors with a single output
terminal.
[0023] The magnetic sensors are characterized by being magnetic
sensors utilizing magneto-resistive effect.
[0024] The magnetic sensors utilizing the magneto-resistive effect
are characterized by being semiconductor magneto-resistive elements
which are disposed on the resin layer side of the printed circuit
board to detect the magnetic flux density in a direction parallel
to the surface of the printed circuit board.
[0025] The magnetic sensors utilizing the magneto-resistive effect
are characterized by being four semiconductor magneto-resistive
elements disposed symmetrically on X and Y axes, which are two axes
on a two dimensional plane of an orthogonal system, wherein two
magnetic sensors on the X axis are electrically connected at a
first connection point; and two magnetic sensors on the Y axis are
electrically connected at a second connection point, and wherein
the pointing device detects variations in ambient magnetic flux
density caused by movement of the ring-like magnet using electric
signals at the first and second connection points.
[0026] The pointing device is characterized by further comprising
an origin returning means for returning the ring-Like magnet to the
origin using magnetic force generated by the ring-like magnet.
[0027] In addition, there is provided an electronic device
incorporating the foregoing pointing device.
[0028] As the magnetic sensors, various types of magnetic sensors
are applicable such as Hall elements, Hall ICs, magneto-resistive
elements (MR devices), magneto-resistive effect ICs (MRICs), and
reed switches. Analog output type magnetic sensors are suitable for
an analog output type pointing device, and digital output type
magnetic sensors are appropriate for a digital output type pointing
device.
[0029] When the Hall elements are used, it is preferable that they
are disposed on the resin layer side of the printed circuit board,
and detect the magnetic flux density in the direction parallel to
the surface of the printed circuit board to further reduce the size
and height of the pointing device.
[0030] When the magnetic sensors utilizing the Hall effect are Hall
ICs each having a single output terminal, the number of the output
signal lines can be reduced compared with the number of those using
the Hall elements, thereby being able to save the space of the
printed circuit board, and to reduce the effect of external
noise.
[0031] When the magnetic sensors utilizing the magneto-resistive
effect to are used, it is preferable that semiconductor
magneto-resistive elements are employed which are disposed on the
resin layer side of the printed circuit board, and detect the
magnetic flux density in the direction parallel to the surface of
the printed circuit board to further reduce the size and height of
the pointing device.
[0032] In addition, it is also possible to dispose four
semiconductor magneto-resistive elements symmetrically two by two
on X and Y axes, which are two axes on a two dimensional plane of
an orthogonal system; to electrically connect the two magnetic
sensors on the X axis at a first connection point; to electrically
connect the two magnetic sensors on the Y axis at a second
connection point; and to detect variations in ambient magnetic flux
density caused by the movement of the ring-like magnet using
electric signals at the first and second connection points. Such a
configuration enables the reduction in the number of the output
signal lines as compared with the case where the Hall elements are
used. Thus, it can save the space for the printed circuit board,
and reduce the effect of the external noise.
[0033] Furthermore, the switch can be placed on the resin layer
side of the printed circuit board. It is also possible to provide a
projection for depressing the switch onto the resin layer portion
facing the switch. Although no restraint is imposed on the type of
the switch, such a switch is suitable which enables a user to
confirm an object by utilizing physical contact with the object,
such as tactile switch, pushbutton switch, tact switch, touch
switch and stroke switch, which allow the user to easily check
pushing it (having tactile feedback), and automatically returns
after depressing the switch. Thus, the tactile switch (also called
dome switch) is preferable to reduce the size and height.
[0034] As for the ring-like magnet, no restraint is imposed on its
type. Thus a variety of ring-like magnet such as ferrite,
samarium-cobalt, and neodymium based magnet which are usually
mass-produced are applicable. To miniaturize the pointing device,
it is essential to reduce the size of the magnet. Accordingly, a
samarium-cobalt or neodymium ring-like magnet which can produce
intense magnetic field with a small body is preferable. In
addition, to reduce the height of the magnet, a bonded magnet that
is more easily molded is better than a bulk magnet. The shape is
not limited to the ring-like form as long as magnetized in the same
manner. Thus, cylindrical or prism-like shapes are also possible.
However, using the ring-like magnet is preferable because this
makes it possible to suppress the total height of the pointing
device even when the switch is mounted on the printed circuit
board.
[0035] As the resin layer, a resin having elasticity is
preferable.
[0036] Although no restraint is imposed on the type of the elastic
resin, a silicone resin that is fit for a wide range of
applications is preferable because it is inexpensive and easily
available.
[0037] As for the ring-like magnet, it is preferable to construct
it in such a manner that it produces the ambient magnetic flux
density variations when moved in nearly parallel to the surface of
the printed circuit board because this enables further reduction in
the height of the pointing device.
[0038] It is preferable that the opposing faces of the resin layer
and the printed circuit board are not bonded.
[0039] It is also preferable that the magnetic sensors are disposed
symmetrically on the X and Y axes, the two axes on the two
dimensional plane on the orthogonal system, and that the ring-like
magnet be placed near the center of the magnetic sensors.
[0040] Besides, the origin returning means of the ring-like magnet
can be provided. Although fixing the ring-like magnet to the resin
layer can make one of such origin returning means, a magnet other
than the ring-like magnet can be added to construct a mechanism for
returning to the origin by utilizing the attractive force or
repulsive force between the two magnets.
[0041] The foregoing configuration enables the reduction in size
and height, the reduction in the leakage magnetic flux density to
the outside, and the improvement in the operating feelings and in
the product life Thus, it can be suitably fitted to a variety of
applications. Moreover, incorporating such a pointing device to
electronic equipment can further reduce the size of the electronic
equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] FIG. 1 is a circuit block diagram showing a configuration of
a pointing device as a conventional example and as an example of a
pointing device in accordance with the present invention;
[0043] FIGS. 2A and 2B are views showing an embodiment of the
pointing device in accordance with the present invention;
[0044] FIGS. 3A and 3B are views showing another embodiment of the
pointing device in accordance with the present invention;
[0045] FIGS. 4A and 4B are views showing still another embodiment
of the pointing device in accordance with the present
invention;
[0046] FIG. 5 is a view showing still another embodiment of the
pointing device in accordance with the present invention;
[0047] FIGS. 6A and 6B are schematic views showing a configuration
of examples 1 and 2 of the pointing device in accordance with the
present invention;
[0048] FIG. 7 is a graph illustrating an output characteristic
example of the pointing device with the configuration of the
example 1;
[0049] FIG. 8 is a graph illustrating another output characteristic
example of the pointing device with the configuration of the
example 1;
[0050] FIG. 9 is a graph illustrating another output characteristic
example of the pointing device with the configuration of the
example 2;
[0051] FIG. 10 is a graph illustrating another output
characteristic example of the pointing device with the
configuration of the example 2;
[0052] FIGS. 11A and 11B are schematic views showing a
configuration of an example 3 of the pointing device in accordance
with the present invention;
[0053] FIG. 12 is a graph illustrating an output characteristic
example of the pointing device with the configuration of the
example 3;
[0054] FIG. 13 is a schematic view showing a configuration of a
conventional pointing device; and
[0055] FIG. 14 is a graph illustrating output characteristics of
the conventional pointing device as shown in FIG. 13.
BEST MODE FOR CARRYING OUT THE INVENTION
[0056] The embodiments in accordance with the present invention
will now be described with reference to the accompanying
drawings.
[0057] A block diagram showing the magnetic detector circuit of the
magnetic detection type pointing device in accordance with the
present invention is the same as the conventional circuit block
diagram as shown in FIG. 1. Thus, the detecting section 1 has four
magnetic sensors (such as Hall elements) 11, and the Hall elements
11 are placed symmetrically two by two on the X and Y axes. Close
to the center of the four Hall elements disposed symmetrically on
the X and Y axes, a ring-like magnet is placed. Because of the
variations in the magnetic flux density involved in the movement of
the ring-like magnet, the output voltages of the Hall elements 11
vary.
[0058] The differential amplifiers 2 differentially amplify the
outputs of the Hall elements 11 on the X axis and Y axis,
respectively. The magnetic detector circuit is configured such that
the outputs of the X and Y axes are adjusted to zero when the
ring-like magnet which is an internally and externally unipolarly
magnetized ring-like magnet is located on the origin; that the
differential amplifiers 2 have outputs in response to the movement
of the ring-like magnet; that the detection control section 3
converts the outputs (analog values) to the X coordinate value and
Y coordinate value; and that the output control section 4 outputs
them.
[0059] FIGS. 2A and 2B are views showing an embodiment of the
pointing device in accordance with the present invention: FIG. 2A
is a top view; and FIG. 2B is a cross-sectional view taken along
the line a-a' of FIG. 2A. In these figures, each reference numeral
11 designates a magnetic sensor, the reference numeral 12
designates a ring-like magnet, 13 designates a silicone resin, 14
designates a printed circuit board and 15 designates a switch
cover. The magnetic sensors 11 are disposed two by two on the X and
Y axes symmetrically on the printed circuit board 14 as described
above. The magnetic sensors 11 detect the magnetic flux density in
the direction parallel to the surface of the printed circuit board
14.
[0060] Although the magnetic sensors 11 are placed outside the ring
magnet 12 in the configuration of FIG. 2A, they can be placed
inside the ring magnet 12. By thus placing the magnetic sensors 11
inside the ring magnet 12, the pointing device can be further
miniaturized. The ring-like magnet 12 is unipolarly magnetized in
NS in the direction of its radius. Which of the magnetization NS is
to be placed outside is not limited. In addition, the opposing
faces of the silicone resin 13 and the printed circuit board 14 are
not bonded.
[0061] The silicone resin 13 is easily deformed by external force,
and is returned to its initial state without the external force by
removing the external force. Thus, when the switch cover 15 is
operated and moved in sane direction, the ring-like magnet 12 moves
in the same manner, and returns to its initial state as soon as the
external force is removed. Using the silicone resin 13 enables the
miniaturization of the moving mechanism and the origin returning
means
[0062] As for the movement of the ring-like magnet 12, a
configuration which allows it to move in a direction approximately
parallel to the surface of the printed circuit board 14 can reduce
the height of the pointing device.
[0063] As for the fixing method of the ring-like magnet 12 to the
silicone resin 13, a simple method using an adhesive can be
employed. In this case, it is preferable to bond them without
applying the adhesive to the entire contacting face between the
ring-like magnet 12 and the silicone resin 13, but by applying to a
portion except for portions close to the outer edge. This is
because this makes it possible to effectively use the elasticity of
the silicone resin 13 and to increase the movable range of the
ring-like magnet 12. In addition, it is preferable that a concave
portion be provided at the mounting location of the ring-like
magnet 12 on silicone resin 13 because of a positioning problem of
the ring-like magnet 12.
[0064] As for the molding of the silicone resin 13, the insert
molding is possible to circumvent the need for bonding the
ring-like magnet 12 after the molding.
[0065] Replacing the ring-like magnet 12 and silicone resin 13 by a
rubber magnet enables further reduction in the height. The magnet
can also be formed by mixing a magnetic material into part of the
silicone resin 13.
[0066] In addition, comparing with a contact type pointing device,
the magnetic detection type pointing device can increase its
product life because it can eliminate abrasion between components
due to contact.
[0067] FIGS. 3A and 3B are views showing another embodiment of the
pointing device in accordance with the present invention: FIG. 3A
is a top view; and FIG. 3B is a cross sectional view taken along
the line b-b' of FIG. 3A. It is a pointing device provided with a
switching function by forming a concave portion in a silicone resin
23 corresponding to the silicone resin 13 of the embodiment as
shown in FIG. 2B, and by installing a switch 28 in the concave
portion. In other words, it has the switch 28 on the silicone resin
23 side of the printed circuit board 24. The silicone resin 23 has
a projection 26 for depressing the switch 28. Besides, the
ring-Like magnet 22 can reduce its height by using a neodymium
bonded magnet.
[0068] Originally, although the pointing device is a device for
outputting the coordinate values of an input point, the switching
function makes a pointing device not only with the coordinate value
output function, but also with a deciding function. It has a
configuration that achieves the switching function by depressing
the switch cover 25 in the direction of the ring-like magnet 22.
Having the switch, it has two signals as a mouse for a personal
computer: the coordinate values and the decision signal.
[0069] As the switch 28, any switch including a push button switch
can be used. However, such switches as a tactile switch, tact
switch, touch switch and stroke switch are suitable which enable
easy checking of depression (with tactile feedback), and return
automatically after the depression, and which confirm an object by
utilizing physical contact with the object.
[0070] In addition, a gap 27 is formed by making the thickness of
the silicone resin 23 in and around the portion on which the
ring-like magnet 22 of the embodiment as shown in FIG. 3B is
mounted thinner than the thickness of the portion of the silicone
resin 23 on which the ring-like magnet 22 is not mounted. The
thinner the silicone resin under the ring-like magnet 22, the
greater the moving range of the ring-like magnet 22. Thus, it is
preferable that the portion involved in the operation of the
silicone resin 23 be made as thin as possible.
[0071] FIGS. 4A and 4B are views each showing still another
embodiment of the pointing device in accordance with the present
invention. It has a configuration that replaces the internally and
externally unipolarly magnetized ring-like magnet in the embodiment
shown in FIG. 3A by a magnet internally and externally magnetized
in a quadrupole (FIG. 4A) or octupole (FIG. 4B). Using the
ring-like magnet 32 with the multipole magnetization can enhance
the converging effect of the magnetic flux and increase the
directivity. Thus the sensitivity of the pointing device is
expected to be increased. As for the number of poles of the
ring-like magnet 32, when it is set at an integer multiple of the
number of the magnetic sensors 31, the magnetic sensors 31 can be
opposed to the pole centers of the ring-like magnet 32 so that the
high signal output is expected. In addition, this makes it possible
to share a signal processing section. Thus, the ring-like magnet 32
is preferably magnetized at M poles (M=K.times.I, where K is the
number of the magnetic sensors used, and I is an integer equal to
or greater than one).
[0072] Furthermore, even if the shape of the ring-like magnet 32 is
changed to a solid cylindrical magnet, the outer surface of the
magnet can be magnetized in the same manner. When the present
invention is carried out using a magnet magnetized in multiple
poles, a magnet with a shape other than a shape of a ring can also
be employed.
[0073] FIG. 5 is a view showing still another embodiment of the
pointing device in accordance with the present invention. It has a
configuration that enhances the origin returning means of the
ring-like magnet in the embodiment as shown in FIG. 2A. As
described above, although the silicone resin itself has a faculty
for returning the ring-like magnet 42 to the origin, the present
embodiment has another magnet 49 inside the ring-like magnet 42 to
return the ring-like magnet 42 to the origin utilizing the
repulsive force between the two magnets. In the present embodiment,
the another magnet 49 is an internally and externally unipolarly
magnetized magnet provided with the S pole on its outer surface.
With such a configuration, the degradation of the origin returning
characteristic due to deterioration from aging of the silicone
resin can be prevented.
[0074] As for all the foregoing embodiments, it is supposed that
the Hall elements are used as the magnetic sensors. Since the Hall
elements have two output terminals each, the length of the output
wiring increases. Thus, the wiring demands a large space and long
distance, and hence the device is susceptible to external noise.
However, using Hall ICs or semiconductor magneto-resistive elements
with a single output terminal as the magnetic sensors enables the
reduction in the number of the output signal lines, thereby being
able to save space of the printed circuit board and to reduce the
effect of the external noise.
[0075] In addition, all the foregoing embodiments assume the
magnetic sensors that detect the magnetic flux density parallel to
the surface of the printed circuit board. However, magnetic sensors
for detecting the magnetic flux density that makes an angle
(between 0 to 90 degrees) with the surface of the printed circuit
board of less than about 60 degrees can offer similar advantages
although the S/N of the pointing device is reduced.
[0076] Furthermore, as for the foregoing embodiments, since they
employ the ring-like magnet magnetized in the outer surface
direction, it is expected that the leakage magnetic flux density to
the top surface of the switch cover be dramatically reduced. Thus,
the problem of losing information of the magnetic card when it is
brought close to the magnet can be cleared up.
[0077] The present invention is not limited to the foregoing
embodiments, but can be modified in a variety of ways.
[0078] Next, concrete examples in accordance with the present
invention will be described.
Example 1
[0079] An example of the output characteristics will be described
when the pointing device is constructed with the configuration of
the foregoing embodiments in accordance with the present
invention.
[0080] FIGS. 6A and 6B are views showing an example 1 of the
pointing device in accordance with the present invention: FIG. 6A
is a top view; and FIG. 6B is a cross sectional view taken along
the line a-a' of FIG. 6A. The ring-like magnet 52 has .phi.13
(external diameter).times..phi.8.8 (internal diameter) and a
thickness of 0.5 (all dimensions in mm). The ring-like magnet 52 is
internally and externally unipolarly magnetized, the outer side of
which is the North pole, and the inner side of which is the South
pole. As the ring-like magnet 52, a neodymium bonded magnet is
used, the coercive force of which is 460 kA/m. The ring-like magnet
52 is held movably in the z direction of FIG. 6B. The movable range
of the ring-like magnet 52 is .+-.1.2 mm in the z direction . The
magnetic sensors 51 are Hall elements that detect the magnetic flux
density in the z direction.
[0081] When the ring-like magnet 52 is placed at the origin, the
distance from the external edge of the ring-like magnet 52 to the
sensor position of the magnetic sensors 51 in the z direction is
denoted by gapZ. Likewise, the distance from the center of the
ring-like magnet 52 to the sensor position of the magnetic sensors
51 in the x direction is denoted by gapX. In this case, the
ring-like magnet 52 is moved in the z direction up to .+-.1.2 mm,
and differences between the magnetic flux density of the right
magnetic sensor 51a and that of the left magnetic sensor 51b are
calculated, the results of which are illustrated in FIG. 7. In this
case, the gapZ is set at 2 mm, and the gapX is set at one of four
values 0 mm, 0.25 mm, 0.5 mm, and 0.75 mm.
[0082] It is found that the magnetic flux density variations equal
to or greater than .+-.20 mT take place when the gapX is set within
0.5 mm, and the ring-like magnet 52 is moved up to .+-.1.2 mm in
the z direction. The values of the magnetic flux density variations
are enough to be detected by the Hall elements 51. In addition, it
is also found that the magnetic flux density variations increase as
the gapX becomes closer to zero, which enables the pointing device
to function more effectively.
[0083] Likewise, FIG. 8 illustrates the results of calculating the
magnetic flux density differences when the gapZ is 1.6 mm. Changing
the gapZ from 2 mm to 1.6 mm approximately doubles the values of
the magnetic flux density differences. From the foregoing results,
it is found that as the values gapZ and gapX are made smaller, the
characteristics of the pointing device are improved.
[0084] In addition, a particular advantage of the present example 1
of the pointing device is that when the ring-like magnet 52
approaches the limit of the movable range (in the example, in a
range where z is equal to or greater than +1.0 mm, or equal to or
less than -1.0 mm), the pointing device has a large output. In
other words, in a range where z is equal to or greater than 1.0 mm
or equal to or less than -1.0 mm, the slopes of the graphs
illustrated in FIGS. 7 and 8 increase.
[0085] For example, it is usual for a user who moves the cursor
from a left end to a right end on a display to wish to move the
cursor as quickly as possible. In such a case, the user usually
moves the ring-like magnet 52 of the pointing device to the right
end of the movable range. In the pointing device in accordance with
the present invention, the cursor moves more quickly as it canes
closer to the limit of the movable range of the ring-like magnet 52
(that is, the portions in which the slopes of the graphs in FIGS. 7
and 8 are large are utilized). Thus, it can be said that the
pointing device in accordance with the present invention has
characteristics closer to the human feelings.
[0086] In contrast, the conventional pointing device has a problem
in that the moving speed of the cursor is reduced as the magnet
approaches the limit of its movable range (which will be described
in a comparative example described later), and hence the operating
feelings are deteriorated. The pointing device in accordance with
the present invention can eliminate the foregoing problem, thereby
being able to improve the operating feelings remarkably.
[0087] Although the magnetic sensors 51 are placed outside the
ring-like magnet in present example 1, it is obvious that similar
advantages are achieved even if they are placed inside the magnet.
In addition, placing them inside the magnet enables further
miniaturization.
Example 2
[0088] Another example of the output characteristics will be
described when the pointing device is constructed with the
configuration of the foregoing embodiment in accordance with the
present invention.
[0089] The main portion of the present example 2 is the same as the
foregoing example 1 as shown in FIGS. 6A and 6B. The ring-like
magnet 52 has .phi.11.78 (external diameter).times..phi.5 (internal
diameter) and a thickness of 0.485 (all dimensions in mm). The
ring-like magnet 52 is internally and externally unipolarly
magnetized, the outer side of which is the North pole, and the
inner side of which is the South pole. As the ring-like magnet 52,
a neodymium bonded magnet is used, the coercive force of which is
398 kA/m. The ring-like magnet 52 is held movably in the z
direction of FIG. 6B. The movable range of the ring-like magnet 52
is .+-.1.2 mm in the z direction. The magnetic sensors 51 are Hall
elements that detect the magnetic flux density in the z
direction.
[0090] As in the example 1, when the ring-like magnet 52 is placed
at the origin, the distance from the external edge of the ring-like
magnet 52 to the sensor position of the magnetic sensors 51 in the
z direction is denoted by gapZ. Likewise, the distance from the
center of the ring-like magnet 52 to the sensor position of the
magnetic sensors 51 in the x direction is denoted by gapX. In this
case, the ring-like magnet 52 is moved up to .+-.1.2 mm in the z
direction, and differences between the magnetic flux density of the
right magnetic sensor 51a and that of the left magnetic sensor 51b
are calculated, the results of which are illustrated in FIG. 9. In
this case, the gapZ is set at 0.7805 mm, and the gapX is set at one
of three values 3 mm, 2.5 mm and 2 mm.
[0091] It is found that only the magnetic flux density variations
of about .+-.10 mT at the most take place when the gapZ is set at 2
mm, and the ring-like magnet 52 is moved up to .+-.1.2 mm in the z
direction. The values of the magnetic flux density variations are
rather insufficient to be detected by the Hall elements 51.
[0092] To improve the pointing device with the foregoing
configuration, the magnetic sensors 51 are replaced by those that
detect the magnetic flux density in the direction in the middle of
the z direction and x direction, that is, in the direction that
makes 45 degrees with the z axis direction and x axis direction, in
which the magnetic flux density from the ring-like magnet 52 is
large. In the present example 2, the magnetic sensor 51a detects
the magnetic flux density in the lower right direction, and the
magnetic sensor 51b detects the magnetic flux density in the lower
left direction. FIG. 10 illustrates the results of calculating the
differences between the magnetic flux density of the right magnetic
sensor 51a and that of the left magnetic sensor 51b with moving the
ring-like magnet 52 with the foregoing construction up to .+-.1.2
mm in the z direction.
[0093] It is found that the values of the magnetic flux density
differences are approximately doubled by replacing the magnetic
sensors for detecting the magnetic flux density in the z direction
by the magnetic sensors for detecting the magnetic flux density in
the direction that makes 45 degrees with the z direction. Fran the
results, it is preferable that the detection direction of the
magnetic sensors be changed appropriately in accordance with the
positional relation between the ring-like magnet 52 and the
magnetic sensors 51 rather than limited to the z direction.
However, as a guide of the detection direction of the magnetic flux
density of the magnetic sensors, it is known that good results are
obtained by setting the angle with the z direction at about 60
degrees or less.
[0094] In addition, an advantage of the present example 2 of the
pointing device is that when the ring-like magnet 52 approaches the
limit of the movable range (in the example, in a range where z is
equal to or greater than +1.0 mm, or equal to or less than -1.0
mm), the pointing device has a large output. In other words, in the
range where z is equal to or greater than 1.0 mm or equal to or
less than -1.0 mm, the slopes of the graphs illustrated in FIG. 10
increase.
[0095] Although the magnetic sensors 51 are placed outside the
ring-like magnet in the present example 2, it is obvious that
similar advantages are achieved even if they are placed inside the
magnet. In addition, placing them inside the magnet enables further
miniaturization.
Example 3
[0096] FIGS. 11A and 11B are views showing an example 3 of the
pointing device in accordance with the present invention: FIG. 11A
is a top view; and FIG. 11B is a cross sectional view taken along
the line a-a' of FIG. 11A, which show an example that replaces the
internally and externally unipolarly magnetized ring-like magnet 52
used by the example 1 by a multipolarly magnetized ring-like magnet
62. The ring-like magnet 62 has .phi.12 (external
diameter).times..phi.8 (internal diameter), and a thickness of 1
(all dimensions in mm). The ring-like magnet 62 is magnetized in
multipolar fashion as shown in FIG. 11A. As the ring-like magnet
62, a neodymium bonded magnet is used. The ring-like magnet 62 is
held movably in the z direction and y direction. The movable range
of the ring-like magnet 62 is .+-.1 mm in the z direction and y
direction, respectively. The magnetic sensors 61 are Hall elements:
those placed at the right and left hand sides of the ring-like
magnet 62 in FIG. 11A detect the magnetic flux density in the z
direction; and those placed upper and lower sides of the ring-like
magnet 62 detect the magnetic flux density in the y direction.
[0097] When the ring-like magnet 62 is placed at the origin, the
distance gapZ from the external edge of the ring-like magnet 62 to
the sensor position of the magnetic sensors 61 in the z direction
is set at 1.6 mm. Likewise , the distance gapX from the center of
the ring-like magnet 62 to the sensor position of the magnetic
sensors 61 in the x direction is set at 0 mm. In this case, the
ring-like magnet 62 is moved up to .+-.1 mm in the z direction and
y direction, and differences between the magnetic flux density of
the right magnetic sensor 61a and that of the left magnetic sensor
61b are calculated, the results of which are illustrated in FIG.
12.
[0098] As in the example 1, good output characteristics of the
pointing device can be confirmed. In addition, it is found that the
characteristics of the pointing device are nearly independent of
the position in the y direction. It is also found that the slopes
of the graphs increase at positions close to the limit of the
movable range of the ring-like magnet 62, which enables the
improvement in the operating feeling of the pointing device.
[0099] Although the present example 3 uses the ring-like magnet 62,
it is obvious that similar advantages can be achieved by using a
solid cylindrical magnet whose outer surface is magnetized in the
same manner. Furthermore, although the present example 3 has the
internal and external walls of the ring-like magnet 62 magnetized
in a quadrupole manner, this is not essential For example, it is
obvious that the multipolar magnetization other than the quadrupole
magnetization can achieve similar advantages.
Comparative Example
[0100] Output characteristics of a configuration of a conventional
magnetic detection type pointing device will be described.
[0101] FIG. 13 is a schematic diagram showing a configuration of a
conventional pointing device. A magnet 72 is a 3.9 mm square by 0.8
mm thick magnet. The magnet 72 is magnetized in the z direction as
shown in FIG. 13. As the magnet 72, a neodymium sintered magnet is
used. In addition, it is held movably in the x direction and y
direction in FIG. 13. The movable range of the magnet 72 is .+-.1
mm in both the directions. The magnetic sensors 71 are Hall device
HQ8002 (trade name) of Asahi Kasei Electronics Co. Ltd., which
includes four Hall elements in a single package. The Hall elements
are for detecting the magnetic flux density in the z direction. In
addition, the distance between the Hall elements at the diagonal
positions is 3.2 mm. FIG. 14 illustrates the measured results of
the differences between the magnetic flux density of the right
magnetic sensor section and that of the left, magnetic sensor
section in HQ8002, when the magnet 72 is moved up to .+-.1 mm in
the x direction and y direction.
[0102] It is found that when the magnet 72 approaches the limit of
the movable range (when x is close to +1.0 mm or -1.0 mm in the
example), the output of the pointing device is reduced. In other
words, when x is close to 1.0 mm or -1.0 mm, the slopes of the
graphs of FIG. 14 are reduced.
[0103] For example, it is usual for a user who moves the cursor
from a left end to a right end on a display to wish to move the
cursor as quickly as possible. In such a case, the user usually
moves the magnet 72 of the pointing device to the right end of the
movable range. In the pointing device of the present comparative
example, since the cursor moves more slowly as the magnet 72
approaches the limit of the movable range (that is, the portions in
which the slopes of the graphs of FIG. 14 are small are utilized),
it is said that the pointing device has characteristics different
from the human feelings. Thus, it deteriorates the operating
feelings expected by the user, and hence the need for its
improvement is undeniable.
[0104] In addition, the output characteristics vary depending on
the position in they direction, which also impairs the operating
feelings expected by the user.
INDUSTRIAL APPLICABILITY
[0105] It is possible for the magnetic detection type pointing
device to provide good operating feelings, to reduce the size and
height, to reduce the leakage magnetic flux density to the outside,
and to lengthen the product life. Thus, a pointing device can be
provided which is suitably applicable to a variety of
applications.
* * * * *