JP3468585B2 - Display device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device used for a meter such as a tachometer or a timepiece, and more specifically, by using an electrostatic actuator as a drive source of the pointer, the position control accuracy of the pointer can be improved. It aims at improvement and thinning.

[0002]

2. Description of the Related Art Conventionally, there has been provided a display device for visually displaying a physical quantity by moving a pointer or the like according to an electric signal obtained by converting the physical quantity. This display device is used, for example, in a meter such as a tachometer of an automobile (which displays the number of revolutions of an engine), a pointer-type timepiece (which displays time), and the like.

In this type of display device, since the pointer is required to move smoothly and the position control accuracy of the pointer is required to be high, there are many cases where the pointer is driven by a motor such as a stepping motor. Further, this type of display device is preferably thin. Especially in the case of a vehicle-mounted display device such as a tachometer, when mounted on a vehicle,
In order to secure a space for mounting other parts, it is required to be as thin as possible.

[0004]

When the motor is used as the driving source of the pointer as described above, in order to reduce the thickness, the pointer is not directly fixed to the rotary shaft of the motor, but the rotary shaft and the pointer are provided as gears. However, in this case, there are problems such as backlash and other hysteresis in the transmission mechanism, and the device becomes complicated. Therefore, when a motor such as a stepping motor is used as a driving source, the thickness of the display device is limited to about 30 mm, and it is difficult to further reduce the thickness. In particular, in the case of the above-described vehicle-mounted display device, if the thickness is about 30 mm, the size and the degree of arrangement of other components are restricted.

The present invention has been made in order to solve the problems in the conventional display device as described above, and an object thereof is to provide a thin display device having a high position control accuracy of the pointer. It is a thing.

[0006]

Therefore, according to the present invention , a pointer shaft having one end inserted into a display plate and rotatably supported, a pointer fixed to one end of the pointer shaft, and the other end of the pointer shaft are provided. fixed and movable electrode plates were, in opposition to the movable electrode plate and a fixed electrode plate in which a plurality of electrodes fixed to the display panel side, and the electrode facing the fixed electrode plate
A plurality of electrodes on the moving side electrode plate,
The polarity is switched clockwise and counterclockwise to the electrode of the electrode plate to apply voltage.
Along with the application, a voltage is applied to the electrodes of the fixed-side electrode plate by switching the polarity, and the moving-side electrode plate is rotationally driven in a desired direction with respect to the fixed-side electrode plate by the attractive force and repulsive force generated between charges. A display device including an electrostatic actuator is provided.

[0007] Specifically, the flexi
The flexible conductor is wound, and the flexible conductor is
It is provided with a circuit for supplying power to the electrodes of the electrode plate.

[0008]

[0009]

In the display device of the present invention , since the pointer is fixed at one end and the pointer shaft rotatably supported is driven to rotate by the electrostatic actuator, the position of the pointer can be precisely controlled. In the present invention , the electrostatic actuator fixes the moving-side electrode plate to the pointer shaft,
Since the fixed electrode plate is fixed to the display plate side so as to face the movable fixed plate, the display device is thin.

Further , in the display device of the present invention , electrodes are provided on both the fixed side electrode plate and the moving side electrode plate, and the moving side electrode plate becomes the fixed side electrode plate due to the attractive force and repulsive force generated between the electrodes. Since it is configured to rotate with respect to each other, the moving-side electrode plate moves with respect to the fixed-side electrode plate for each electrode.

[0011]

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in the drawings. 1 and 2 show the first embodiment of the present invention.
3 illustrates a display device according to an example. The display device of the first embodiment is a tachometer for automobiles. 1 in the figure
Is a short cylindrical case having an opening 1a at the top. At the central portion of the bottom portion 1b of the case 1, a tapered support shaft 1c is provided so as to extend toward the tip. On the other hand, the opening 1b of the case 1 is closed by a disc-shaped display plate 2. A circular hole 2a penetrating in the plate thickness direction is provided at the center of the display plate 2. The support shaft 1c is loosely inserted in the hole 2a, and the tip portion of the support shaft 1c projects from the inside of the case 1 onto the display plate 2.

The pointer shaft indicated by 3 in the drawing has a tapered hole 3a whose diameter decreases from the lower end side to the upper end side in the drawing, and the tapered hole 3a is fitted onto the support shaft 1c. The dimensions of the tapered hole 3a are set so that a gap is formed between the support shaft 1c and the peripheral surface of the tapered hole 3a. Further, lubricating oil is injected into this gap, and the pointer shaft 3 is rotatably supported by the support shaft 1c.

At the lower end of the pointer shaft 3 located inside the case 1 which is closed by the display plate 2, there is provided a disk-shaped jaw 3b whose diameter is expanded outward in the radial direction. On the upper surface 3d of the jaw 3b, a circular hole 4 that penetrates in the plate thickness direction in the central portion is formed.
The drive plate 4 made of a disk provided with a is fixed.

A pointer 6 is fixed to the upper end of a pointer shaft 3 protruding from the display plate 2 to the outside of the case 1. The pointer 6 includes an indicator 6b, one end 6a of which indicates a predetermined position on the display plate 2, and a base 6d, which is integrally provided at the other end 6c of the indicator 6b. The base 6d is provided with a circular hole 6e, and the pointer 6 is fixed to the pointer shaft 3 by externally fitting the hole 6e on the upper end of the pointer shaft 3. As described above, in the first embodiment, the pointer 6, the pointer shaft 3 and the drive plate 4 are integrally fixed, and when the drive plate 4 rotates, the pointer shaft 3 and the pointer 6 also rotate.

On the upper surface of the indicating portion 6b of the pointer 6, there is LE
A light-emitting body 7 made of D is arranged. This luminous body 7
It is connected to terminals 10a and 10b of a conductive portion 9 described later via terminals 8a and 8b provided on the base portion 6d.

As shown in detail in FIG. 3, a conductive portion 9 made of a flexible substrate is provided on the outer circumference of the pointer shaft 3. The conductive portion 9 includes terminals 10a to 10h and a copper foil 11 that connects the terminals 10a to 10h to form a required circuit, and the entire portion other than the terminals 10a to 10h is covered with an insulating film 12. There is. This conductive portion 9 is the same as the pointer 6 described above.
It is provided with two circuits for supplying power to the light-emitting body 7 provided in the instruction section 6b. These two circuits include terminals 10a and 10b connected to the terminals 8a and 8b provided on the pointer 6, and a terminal 10c connected to the flexible conductor 13 side described later.
And 10d. In addition, the conductive portion 9 includes two circuits for supplying power to the A-phase and B-phase electrodes 25a and 25b of the moving-side electrode plate 21, which will be described later. These two circuits are terminals 10e and 10f connected to the moving electrode plate 21 side.
And terminals 10g, 1 connected to the flexible conductor 13 side
It has 0h. The conductive portion 9 does not necessarily have to be formed of a flexible substrate, and may be formed of a normal electric wire as long as it is thin.

A flexible conductor 13 is wound around the outer circumference of the pointer shaft 3. This flexible conductor 1
As is well known in the art, 3 is a resin thin plate 13a having a copper foil 14 adhered thereto, which is used for supplying power to the luminous body 7 of the pointer 6.
Circuit and electrodes 25a, 2 of the moving-side electrode plate 21 described later.
2b for powering 5b. Each circuit has terminals 10c, 10d, 10g, 10 of the conductive portion 9 described above.
A terminal 15 having terminals 15a, 15b, 15c, 15d connected to h at one end and connected to the conductor 16 at the other end
e, 15f, 15g, 15h. This conductor 1
6 is arranged in a groove 2c provided on the lower surface 2b of the display plate 2, and is connected to a relay 47 described later.

A dial 2d is formed on the upper surface of the display plate 2 by writing required numbers and the like. The same LED as the indicator 6b of the pointer 6 is provided at a required position on the dial 2d.
Is attached to the light emitter 17. This luminous body 17
Is connected to a relay 47, which will be described later, via a conducting wire 18 arranged in the display board 2.

The display device of this embodiment is constructed so that the drive plate 4 is driven by the electrostatic actuator 20 schematically shown in FIG. The electrostatic actuator 20 is fixed on the lower surface 2b of the display plate 2 so as to face the moving side electrode plate 21 and the moving side electrode plate 21 that is fixed to the upper surface 4b of the drive plate 4 by facing. The fixed side electrode plate 22 is provided.

As shown in FIG. 5, the moving-side electrode plate 21 has a disk shape having a circular hole 21a penetrating in the plate thickness direction at the center, and has a surface 23a on the lower side in FIG. 4 of the substrate 23. The drive plate 4 is attached and fixed to the upper surface 4b. Also,
On the surface 23b of the moving-side electrode plate 21 on the upper side of the substrate 23,
An insulating layer 24 made of a dielectric material is provided, and a plurality of electrodes 25a, 25b ... 25a, 25b are arranged on this insulating layer 24.

In the first embodiment, the moving side electrode plate 21
Are two groups of electrodes 25a, which form the A phase and the B phase, respectively.
25b. The electrode 25a constituting the A phase has a long and narrow strip shape, and the current collector 2 is provided in an annular shape around the inner side of the movable electrode plate 21, that is, around the circular hole 21a.
6 are provided radially outward at equal angular intervals. On the other hand, the electrode 25b constituting the B-phase has a strip-like shape like the electrode of the A-phase, and is radially arranged at equal angular intervals from the current collecting portion 27 annularly provided on the outer peripheral side of the moving-side electrode plate 21. It is provided inward. In the first embodiment, the angular interval between the electrodes 25a forming the A phase and the electrode 25b forming the B phase
The angular intervals of are the same, and if this angular interval is θ,
The B-phase electrode 25b is arranged with a phase shifted by 1 / 3θ in the clockwise direction in FIG. 5 with respect to the A-phase electrode 25a. In the moving-side electrode plate 21 of the first embodiment, the electrode 2 is used as described above.
Since 5a and 25b are arranged, the arrangement pattern of the electrodes 25a and 25b is "A" as schematically shown in FIG.
Phase, phase B, none ".

A terminal 28 is provided on the A-phase current collector 26. On the other hand, a conducting portion 29 extending from the B-phase current collecting portion 27 to the vicinity of the circular hole is provided, and a terminal 30 is provided at the tip of the conducting portion 29. This terminal 29,
Reference numeral 30 denotes conductors 31a and 31b arranged on the upper surface of the drive plate 4.
The terminals 32a and 32b at the other ends of the conductors 31a and 31b are connected to the terminals 10e and 10f of the conductive portion 9.
Connected to.

On the other hand, as shown in detail in FIG. 6, the fixed-side electrode plate 22 is in the shape of a disc having a circular hole 22a formed at its center and penetrating in the plate thickness direction, as in the case of the movable-side electrode plate 21. The upper surface 33a of the substrate 33 in FIG. 4 is attached and fixed to the lower surface 2b of the display plate 2. An insulating layer 34 made of a dielectric is provided on the surface 33b of the fixed-side electrode plate 22 on the lower side of the substrate 33, and a plurality of electrodes 35 are provided on the insulating layer 34.
a, 35b, 35c ... 35a, 35b, 35c ...
-35a, 35b, and 35c are provided. These electrodes 35a, 35b, 35c are all elongated strips and are arranged at equal angular intervals (angle θ) for each phase.
The three phases of the V phase, the V phase, and the W phase are formed.

The electrodes 35a constituting the U-phase are radially outward at the above-mentioned angular intervals from the inner circumferential side of the fixed-side electrode plate 22, that is, the current collecting portion 36 annularly provided around the circular hole 22a. It is provided. The electrode 35b forming the V phase is
A current collector 3 annularly provided on the outer peripheral side of the moving-side electrode plate 21.
It is provided inward in the radial direction from No. 7, and the phase is shifted by 1 / 3θ in the clockwise direction in FIG. 6 with respect to the electrode 35a constituting the U phase. Electrode 35c constituting W phase
Is a conductive portion 38 that penetrates the fixed-side electrode plate 22 in the plate thickness direction.
The current collector 3 provided in an annular shape on the upper surface 33a of the substrate 33 via the
9 is connected. In addition, the electrode 35c forming the W phase
Are arranged by shifting the phase by 2 / 3θ in the clockwise direction in FIG. 6 with respect to the electrode 35a forming the U phase.

From the U-phase current collector 36 to the fixed-side electrode plate 2
2 is provided with a conducting portion 41 extending to the outer peripheral side.
A terminal 42 is provided at the tip of 1. Further, a terminal 43 is provided on the V-phase current collector 37. Furthermore, a conducting portion 44 extending from the W-phase current collecting portion 39 to the outer peripheral side of the fixed-side electrode plate 22 is provided, and a terminal 45 is provided at the tip of the conducting portion 44. These U-phase, V-phase and W-phase terminals 42, 4
3, 45 are connected to a relay 47 via a conducting wire 46 arranged on the lower surface 2b of the display board 2. Since the electrodes 35a, 35b, and 35c are arranged on the fixed-side electrode plate 22 as described above, the electrodes 35a, 35b, and 35c are arranged as shown in FIG.
The arrangement pattern of 35b and 35c is "U phase, V phase, W phase"
Has become.

In this first embodiment, the moving side electrode plate 2 is
While the voltage is fixedly applied to the A-phase and B-phase electrodes 25a and 25b of No. 1, the U-phase and V of the fixed-side electrode plate 22 are applied.
The polarity of the electrodes 35a, 35b, 35c of the W-phase and the W-phase is switched and voltage is applied to the electrodes 2 of the moving-side electrode plate 21.
5a, 25b and electrodes 35a, 35 of the fixed side electrode plate 22
The moving-side electrode plate 21 rotates with respect to the fixed-side electrode plate 22 due to the electrostatic attraction and repulsive force generated between b and 35c, and the moving-side electrode plate 21 rotates, so that the drive plate 4, the pointer shaft 3, and The pointer 6 rotates together.

The relay 47 converts the engine speed detected by the sensor 51 (shown only in FIG. 1) into an electric signal and, at the same time, controls means 52 (FIG. 1) for instructing the drive of the pointer 6 according to this signal. , And a power source 53. The relay 47 has the control means 52.
In response to a command from the above, the polarity is switched to the electrodes 35a, 35b, 35c of the fixed-side electrode plate 22 of the electrostatic actuator 20 to apply a voltage, while the moving-side electrode plate 2
A voltage is fixedly applied to the first electrode 25a, 25b. Further, the relay 47 supplies power to the luminous body 7 of the pointer 6 and the luminous body 17 of the display board 2.

Next, the operation of the first embodiment will be described. First, as shown by the arrow R, when moving the moving-side electrode plate 21 clockwise, as shown in FIG. 7, the “+” voltage is fixed to the A-phase electrode 25a of the moving-side electrode plate 21. On the other hand, a "-" voltage is fixedly applied to the B-phase electrode 25b.

On the other hand, to the fixed side electrode plate 22, a voltage is applied to the U-phase, V-phase and W-phase electrodes 35a, 35b and 35c by switching the polarities. In the first embodiment, assuming that one cycle is 360 °, the V phase and the W phase are delayed by 240 ° and 120 °, respectively, with respect to the U phase, and voltages are applied in the same pattern.

First, during the period of 0 ° to 120 °, the U phase is "+", the V phase is "-", and the W phase is "+". At this time,
As shown in (A), the electrodes 25a of the moving-side electrode plate 21,
25b and U-phase and V-phase electrodes 35a of the fixed-side electrode plate 22,
A repulsive force is generated between the movable side electrode plate 21 and the fixed side electrode plate 22 in the direction of separating them from each other. Further, between the electrodes 25a and 25b of the moving-side electrode plate 21 and the W-phase electrode 35c of the fixed-side electrode plate 22, repulsive force and suction are applied so as to move the moving-side electrode plate 21 in the direction of arrow R. A force acts on the moving-side electrode plate 21 so that only one electrode 35a corresponds to the arrow R.
Move in the direction.

Next, during the period of 120 ° to 240 °, the U phase is "+", the V phase is "+", and the W phase is "-". At this time,
As shown in (B), the electrodes 25a of the moving-side electrode plate 21,
25b and V-phase and W-phase electrodes 35b of the fixed-side electrode plate 22,
A repulsive force acts in a direction of separating the moving side electrode plate 21 from 35c, and a repulsive force between the U-phase electrode 35a and the moving side electrode plate 21 in a direction of an arrow R. ,
The suction force works. Therefore, the moving-side electrode plate 21 moves in the direction of arrow R by one electrode 25a, 25b.

Further, during the period of 240 ° to 360 °, U
The phase is “−”, the V phase is “+”, and the W phase is “+”. At this time, as shown in FIG. 8C, the electrode 25 of the moving-side electrode plate 21 is
a, 25b and U-phase and W-phase electrodes 35 of the fixed-side electrode plate 22
a and 35c, a repulsive force acts in the direction of separating the moving-side electrode plate 21, and the moving-side electrode plate 21 is moved in the direction of arrow R between the V-phase electrode 35b and Repulsive force and suction force are applied. Therefore, the moving-side electrode plate 21 moves in the direction of arrow R by one electrode 25a, 25b.

As described above, the electrode 35 of the fixed-side electrode plate 22 is
By switching the voltage applied to a, 35b, and 35c, the moving side electrode plate 21 rotates in the direction of arrow R for each one of the electrodes 25a and 25b.

When stopping the movement of the moving side electrode plate 21, as shown in FIG. 7, the polarities of the A-phase and B-phase electrodes 25a and 25b of the moving side electrode plate 21 are set to "0", and U-phase, V-phase, W-phase electrodes 35a, 35 of the fixed-side electrode plate 22
The polarities of b and 35c are "0".

On the other hand, as shown by the arrow L, when the moving side electrode plate 21 is rotated counterclockwise in the figure, a "-" voltage is applied to the A phase electrode 25a of the moving side electrode plate 21. , "+" Voltage is applied to the B-phase electrode 25b. Further, in this case, a voltage is applied to the U-phase, V-phase, and W-phase electrodes of the fixed-side electrode plate 22 in a pattern opposite to that when the movable-side electrode plate 21 is rotated in the arrow R direction. That is, the U phase is “+”, the V phase is “−”, the W phase is “+” during the period of 0 ° to 120 °, and the U phase is during the period of 120 ° to 240 °.
Phase “-”, V phase “+”, W phase “+”, 240 ° to 360
During the period of °, the U phase is “+”, the V phase is “+”, and the W phase is “−”. By applying the voltage in this manner, the moving-side electrode plate 21 rotates in the direction of arrow L for each one of the electrodes 25a and 25b.

As described above, in the first embodiment, the voltage applied to the electrodes 35a, 35b and 35c of the fixed side electrode plate 22 is switched so that the moving side electrode plate 21 is moved to the electrode 25.
Each of a and 25b can be rotated with respect to the fixed-side electrode plate 22, and when the movable-side electrode plate 21 is rotated, it is integrated with the movable-side electrode plate 21 via the drive plate 4 and the pointer shaft 3. The pointer 6 that is moving also moves. Therefore, in the first embodiment, the pointer 6 can be moved smoothly and the position of the pointer 6 can be precisely controlled.

Further, in the first embodiment, since the drive source of the pointer 6 is the electrostatic actuator as described above, the thickness of the device can be set to about 5 to 6 mm, which is different from the conventional display device. The device can be made thinner as compared with the case where a stepping motor or the like is used as the drive source.

Next, a second embodiment of the present invention will be described. In the second embodiment, as shown in FIGS. 9 and 10, the structure of the moving-side electrode plate 21 is different from that of the first embodiment. That is, in the second embodiment, the moving electrode plate 21 is
A C-phase electrode 25c is provided with a phase shift of 1 / 3θ clockwise from the phase electrode 25b. This C-phase electrode is
Similar to the V-phase of the fixed-side electrode plate 22, the movable-side electrode plate 21 is connected to a current collecting part 56 provided in an annular lower surface via a conducting part 55 penetrating in the plate thickness direction. As described above, in the second embodiment, the moving-side electrode plates are arranged in the order of "A phase, B phase, C phase". Further, as shown in FIG. 9, the electrodes 25a, 25
Of b and 25c, the B-phase electrode 25b and the C-phase electrode 25
c is connected to form a BC phase. The other structure of the second embodiment is similar to that of the first embodiment described above.

When the pointer 6 is moved in the second embodiment, a voltage is applied as in the first embodiment, as shown in FIG. First, the moving-side electrode plate 2 is moved in the direction of arrow R.
In the case of moving 1, the “+” voltage is fixedly applied to the A-phase electrode 25a and the “-” voltage is fixedly applied to the BC-phase electrode 25b of the moving-side electrode plate 21. In addition, the electrode 3 of the fixed-side electrode plate 22
For 5a, 35b, and 35c, the U phase is "+", the V phase is "-", and the W phase is "+" during the period of 0 ° to 120 ° (Fig. 12).
See (A). ), The U phase “+”, the V phase “+”, the W phase “−” (see FIG. 12B) during the 120 ° to 240 ° period, and the U phase “+” during the 240 ° to 360 ° period. -", V
The phase is "+" and the W phase is "+" (see FIG. 12C).
By applying the voltage in this manner, the moving-side electrode plate 2
1 indicates an arrow R for each electrode 25a, 25b, 25c.
Rotate in the direction.

When moving the moving-side electrode plate 21 in the direction of the arrow L, "-" is added to the phase A of the moving-side electrode plate 21.
A “+” electrode is fixedly applied to the BC phase. Also, for the electrodes 35a, 35b, 35c of the fixed-side electrode plate 22, during the period of 0 ° to 120 °, the U phase “+”, the V phase “−”, the W phase “+”, and the 120 ° to 240 °. The period of ゜ is U
Phase “-”, V phase “+”, W phase “+”, 240 ° to 360
During the period of °, the U phase is “+”, the V phase is “+”, and the W phase is “−”. By applying the voltage in this way, the moving-side electrode plate 21 rotates in the direction of the arrow L for each one of the electrodes 25a, 25b, 25c.

In the second embodiment, as in the first embodiment, the voltage applied to the electrodes 35a, 35b and 35c of the fixed side electrode plate 22 is switched to change the moving side electrode plate 2.
Since 1 can be moved for each one of the electrodes 25a, 25b, 25c, the position of the pointer 6 can be precisely controlled. Further, in the second embodiment, since the drive source of the pointer is the electrostatic actuator 20 as described above, it is possible to reduce the thickness of the entire device.

Further, in the second embodiment, the moving side electrode plate 21
The three-phase electrodes 25a, 25b, 25 of A phase, B phase, and C phase
c is provided, and the fixed-side electrode plate 22 is also provided with U-phase, V-phase, and W-phase three-phase electrodes 35a, 35b, and 35c, and the moving-side electrode plate 21 and the fixed-side electrode plate 22 have substantially the same structure. Therefore, the parts can be shared and the cost can be reduced.

In the second embodiment, the C-phase electrode 25c may be connected to the current collecting portion 27 of the B-phase electrode 25b, and the current collecting portion 56 in FIG. 10 may be omitted.

Next , a third embodiment will be described. In the third embodiment, as shown in FIG. 13, the moving side electrode plate 2 is
1 is an insulating layer 2 made of a dielectric material on the upper surface 23a of the substrate 23.
4 is provided, no electrode is provided on the insulating layer 24, and the electrodes 35a, 35b, and 35c of the fixed-side electrode plate 22 are used to induce charges in the insulating layer 24. The other structure of the third embodiment is similar to that of the first embodiment described above. The display device of the third embodiment is a moving-side electrode plate.
21. Since the 21 side is not provided with an electrode, claim 1 and claim 2
Although not included in the technical scope of
The present invention is applicable to the point that the
Pass through.

In the third embodiment, as shown in FIG. 14, if the period of the voltage applied to the electrodes 35a, 35b and 35c of the fixed side electrode plate 22 is 360 °, 0 ° to 120 °.
In order to induce electric charges in the moving-side electrode plate 21 during the first required time α of the angle (first step), 120 ° to 240 ° (second step), and 240 ° to 360 ° (third step). Then, a voltage is applied to the electrodes 35a, 35b, 35c, and a voltage is applied to drive the moving-side electrode plate 21 for the remaining predetermined time β.

First, when the movable electrode plate 21 is rotated in the direction of arrow R, the U-phase electrode 35a is "+", V phase for the first predetermined time α of 0 ° to 120 ° (first step). Electrode 35b of "-", W-phase electrode 35c is "0",
As shown in FIG. 15A, charges are induced in the insulating layer 24 of the moving-side electrode plate 21 in the arrangement of “−”, “+”, and “0”.
Next, during the remaining predetermined time β of the first step, as shown in FIG.
As shown in (B), the U-phase electrode 35a is "+", the V-phase electrode 35b is "+", and the W-phase electrode 35c is "-". At this time, as shown in FIG. 15B, the electrodes 35a, 35b, 35c of the fixed electrode plate 22 and the movable electrode plate 21 are removed.
Attraction and repulsion generated between the electric charge induced in the
As shown in FIG. 15C, the moving-side electrode plate 21 is connected to the electrode 3
Only one of 5a, 35b, and 35c moves in the direction of arrow R.

Next, at 120 ° to 240 ° (second step), the U-phase electrode 35a is "0", the V-phase electrode 35b is "+", and the W-phase electrode 35c is for the first predetermined time α.
Is "-", and the moving-side electrode plate 21 has "0", "-",
Electric charges are induced by the arrangement of “+”, and for the remaining predetermined time β,
The U-phase electrode 35a is "-", the V-phase electrode 35b is "+", the W-phase electrode 35c is "+", and the moving-side electrode plate 21 is provided with an arrow R for one electrode 35a, 35b, 35c. Move in the direction of.

From 240 ° to 360 ° (third step), the U-phase electrode 35a is "-" for the first predetermined time α.
The V-phase electrode 35b is "0", and the W-phase electrode 35c is "+".
Then, electric charges are induced in the moving-side electrode plate 21 in the arrangement of “+”, “0”, and “−”, and the U-phase electrode 35a is set to “+” and the V-phase electrode 35b is set to “+” for the remaining predetermined time β. "-", The W-phase electrode 35c is set to "+", and the moving side electrode plate 21 is set to the electrode 35.
Only one a, 35b, 35c is moved in the direction of arrow R.

When stopping the moving side electrode plate 21,
U-phase, V-phase, and W-phase electrodes 35a of the fixed-side electrode plate 22,
35b and 35c are all set to "0".

When the moving side electrode is moved in the direction of arrow L, the pattern of the electrodes 35 of the fixed side electrode plate 22 is opposite to that in the case of moving the moving side electrode plate 21 in the direction of arrow R.
The polarities of a, 35b, and 35c are applied. That is, FIG.
As shown in FIG. 4, in the 0 ° to 120 ° (first step), the U-phase electrode 35a is “−” for the first predetermined time α.
The V-phase electrode 35b is "0", and the W-phase electrode 35C is "+".
For the remaining predetermined time β, the U-phase electrode 35a is “+”, the V-phase electrode 35b is “−”, and the W-phase electrode 35c.
Is "+". Next, in 120 ° to 240 ° (second step), the U-phase electrode 35a is “0”, the V-phase electrode 35b is “+”, and the W-phase electrode 35c is the first predetermined time α.
Is set to "-", and the U-phase electrode 35a is used for the remaining predetermined time β.
"-", V-phase electrode 35b is "+", W-phase electrode 35
Let c be "+". Further, during the period of 240 ° to 360 °, the U-phase electrode 35a is “+”, the V-phase electrode 35b is “−”, and the W-phase electrode 35c is for the first predetermined time α.
Is set to “0”, and for the remaining predetermined time β, the U-phase electrode 35
a is “+”, V-phase electrode 35b is “+”, W-phase electrode 3
Let 5c be "-".

In the third embodiment, as described above, the voltage applied to the electrodes 35a, 35b and 35c of the fixed electrode plate 22 is switched to cause the movable electrode plate 21 to move to the electrode 3.
It is possible to move every 5a, 35b, 35c. In the structure of the third embodiment, although the accuracy is slightly lowered as compared with the first and second embodiments in which the moving side electrode plate 21 is also provided with an electrode as described above, the position of the pointer 6 is compared. It can be controlled with extremely high precision. Further, in the second embodiment, since the drive source of the pointer is an electrostatic actuator, it is possible to reduce the thickness of the entire device.

Further, in the third embodiment, since the movable electrode plate 21 is not provided with the electrodes as described above, the structure is simple and the cost can be reduced.

The present invention is not limited to the above embodiments, but various modifications can be made. For example, the display device according to the above embodiments is a tachometer for automobiles. The invention can be applied to other display devices such as a pointer type timepiece.

[0055]

As is apparent from the above description, in the display device of the present invention , the pointer is fixed at one end and the pointer shaft rotatably supported is rotationally driven by the electrostatic actuator. Therefore, the position of the pointer can be precisely controlled. Further, in the present invention , the electrostatic actuator has a structure in which the moving side electrode plate is fixed to the above-mentioned shaft and the fixed side electrode plate is fixed to the display plate side so as to face the moving side fixed plate. The device can be made thinner as compared with the case where the drive source is used. For example, when this display device is used as a display device for an automobile, the thickness of the device can be set to about 5 to 6 mm, so that the degree of freedom in dimensioning and arranging other components is increased.

Further, in the display device of the present invention , in particular, electrodes are provided on both the fixed-side electrode plate and the moving-side electrode plate, and the moving-side electrode plate is fixed to the fixed-side electrode plate by the attractive force and repulsive force generated between the electrodes. Since it is configured to rotate with respect to the plate, the movable electrode plate can be moved with respect to the fixed electrode plate for each electrode, and the position of the pointer can be controlled with high accuracy.

[0057]

[Brief description of drawings]

FIG. 1 shows a display device according to a first embodiment of the present invention,
It is sectional drawing of the II line of FIG.

FIG. 2 is a front view showing the display device according to the first embodiment of the present invention.

FIG. 3 is an exploded perspective view of essential parts of the first embodiment.

FIG. 4 is a schematic view showing the electrostatic actuator of the first embodiment.

FIG. 5 is a front view showing a moving-side electrode plate of the first embodiment.

FIG. 6 is a front view showing a fixed-side electrode plate of the first embodiment.

FIG. 7 is a diagram showing application of voltage to electrodes in the first embodiment.

8A, 8B, and 8C are schematic views showing the operation of the first embodiment.

FIG. 9 is a schematic view showing an electrostatic actuator of a second embodiment.

FIG. 10 is a front view showing a moving-side electrode plate according to a second embodiment.

FIG. 11 is a diagram showing application of voltage to electrodes in a second embodiment.

12 (A), (B) and (C) are schematic views showing the operation of the second embodiment.

FIG. 13 is a schematic view showing an electrostatic actuator of a third embodiment.

FIG. 14 is a diagram showing voltage application to electrodes in a third embodiment.

15 (A), (B) and (C) are schematic views showing the operation of the third embodiment.

[Explanation of symbols]

1 case 2 display board 1c spindle 3 pointer axis 6 guidelines 20 Electrostatic actuator 21 Moving side electrode plate 22 Fixed side electrode plate 25a to 25c electrodes 35a-35c electrodes

Continued Front Page (72) Inventor Daisuke Oba 390 Umeda, Kosai City, Shizuoka Prefecture Asmo Co., Ltd. (56) References JP-A-4-198890 (JP, A) JP-A 64-66714 (JP, A) Special Kai 63-205591 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G04C 3/00 G01D 11/00-13/28 H02N 1/00-15/04

Claims (2)

(57) [Claims] 1. A pointer shaft having one end inserted into a display plate and rotatably supported, a pointer fixed to one end of the pointer shaft, a movable electrode plate fixed to the other end of the pointer shaft, and the movement. opposite to the side electrode plate and a fixed electrode plate in which a plurality of electrodes fixed to the display panel side, electrodeposition of the fixed-side electrode plate
A plurality of electrodes are provided on the moving-side electrode plate so as to face the poles,
The polarity of the electrode on the moving side electrode plate is switched clockwise and counterclockwise.
Voltage is applied to the fixed-side electrode plate , and the voltage is applied to the electrode of the fixed-side electrode plate by switching the polarity, and the moving-side electrode plate is moved in a desired direction with respect to the fixed-side electrode plate by the attractive force and repulsive force generated between the charges. A display device including an electrostatic actuator that is rotationally driven. 2. A flexible conductor is wound around the outer circumference of the pointer.
The flexible conductor is rotated and the flexible conductor is an electrode of the moving electrode plate.
A table according to claim 1, comprising a circuit for powering the
Indicating device.