Instrumental device

An instrumental device is provided which includes a variable display portion and a pointer moving around the variable display portion and achieves excellent response and resistance to vibration without complicating the shape of a member. The instrumental device has a display plate 21 having a variable display portion 21b, a pointer 23 moving around the variable display portion 21b, and pointer drive means 25, 26 provided on the back-face side of the display plate 21 for moving the pointer 23. The instrumental device includes a guide rail portion 22 provided in the display plate 21 to surround the periphery of the variable display portion 21b, the pointer 23 being located on the guide rail portion 22, a holding portion 24 holding the pointer 23 movably along the guide rail portion 22, a first magnet 24c provided in the pointer 23 or the holding portion 24, and a second magnet 25a provided in the pointer drive means 25, 26 such that the second magnet 25a is opposite to the first magnet 24c,

RELATED APPLICATIONS

This application is the U.S. National Phase under 35 U.S.C. §371 of International Application No. PCT/JP2008/072801, filed on Dec. 16, 2008, which in turn claims the benefit of Japanese Application No. 2008-019709, filed on Jan. 30, 2008, the disclosures of which Applications are incorporated by reference herein.

TECHNICAL FIELD

The present invention relates to an instrument device which includes a variable display portion and a pointer moving around the variable display portion.

BACKGROUND ART

There have been conventionally instrumental devices in which a pointer points at an indicating portion on a dial (display plate) to display predetermined information. In such an instrumental device, the pointer is directly secured to a rotation shaft of pointer drive means such as a stepping motor, and the pointer is rotated in association with rotation drive of the pointer drive means and thus caused to point at the indicating portion.

Some of the instrumental devices include a large variable display portion such as a liquid crystal display portion at the center of a display plate such that the variable display portion displays predetermined information, and also includes a pointer moving around the variable display portion such that the pointer displays predetermined information. Such a configuration is disclosed, for example in Patent Document 1.

An instrumental device disclosed in Patent Document 1 is formed to use a pointer having a bent shape which bypasses a variable display portion from a back-face side to a front-face side of a display plate.

DISCLOSURE OF THE INVENTION

Problems that the Invention is to Solve

The instrumental device of the configuration as disclosed in Patent Document 1, however, has the problem in which the complicated structure of the pointer increases the length and weight of the pointer to prevent rotation of the pointer with excellent response. In addition, since the pointer is simply secured to the pointer drive means, the problem of poor resistance to vibration is presented when the device is used for a vehicle instrument used in harsh environments. Thus, the instrumental devices have potential for improvement.

The present invention has been made in view of the abovementioned problems, and it is an object thereof to provide an instrumental device which includes a variable display portion and a pointer moving around the variable display portion and achieves excellent response and resistance to vibration without complicating the shape of a member.

Means for Solving the Problems

To solve the problems, the present invention is characterized by an instrumental device having a display plate having a variable display portion, a pointer moving around the variable display portion, and pointer drive means provided on the back-face side of the display plate for moving the pointer, including a guide rail portion provided in the display plate to surround the periphery of the variable display portion, the pointer being located on the guide rail portion, a holding portion holding the pointer movably along the guide rail portion, a first magnet provided in the pointer or the holding portion, and a second magnet provided in the pointer drive means such that the second magnet is opposite to the first magnet, wherein the pointer is rotated in association with rotation drive of the pointer drive means by attraction force of the first and second magnets.

The present invention is characterized by including a regulating portion provided for the holding portion and regulating the position of the pointer located on the guide rail portion, and a guide portion provided for the guide rail portion and having a shape conforming to the regulating portion.

The present invention is characterized in that the regulating portion is formed of a protrusion portion protruding from the holding portion.

The present invention is characterized in that the regulating portion is formed of a rotation member rotating along the guide portion.

The present invention is characterized in that each of the regulating portion and the guide portion has an inclined surface, the inclined surfaces thereof abutting each other.

Advantage of the Invention

The present invention relates to an instrumental device which includes a variable display portion and a pointer moving around the variable display portion and achieves excellent response and resistance to vibration without complicating the shape of a member.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, a first embodiment in which the present invention is applied to a vehicle combination meter will be described with reference to the accompanying drawings.

InFIG. 1, reference numeral1shows a housing. The housing1has a shade member and a case body to accommodate four indicators, that is, a speed meter2, a rotation meter3, a fuel meter4, and a water-temperature meter5. The speed meter2is larger than the rotation meter3, the fuel meter4, and the water-temperature meter5, and is placed between the rotation meter3, and the fuel meter4and the water-temperature meter5. The speed meter2has a display plate21and a pointer23. The rotation meter3, the fuel meter4, and the water-temperature meter5have dials31,41,51, and pointers32,42,52, respectively. The dials31,41,51are provided by forming indicating portions3a,4a,5athree-dimensionally on substrates made of light-transmitting resin (for example, polycarbonate) and forming light-shield portions through printing except for character portions3b,4b,5b, respectively. The pointers32,42,52are rotated by a stepping motor (not shown) to point at the indicating portions3a,4a,5aof the dials31,41,51, respectively.

FIG. 2is an enlarged section view showing main portions. The speed meter2has the display plate21, a guide rail portion22, the pointer23, a holding portion24, an arm member25, and the stepping motor26. Reference numeral27shows a circuit substrate on which the stepping motor26is mounted.

The display plate21is formed of a light-transmitting substrate21aand a liquid crystal display portion (variable display portion)21b.

The light-transmitting substrate21ais made of light-transmitting resin (for example, acrylic or polycarbonate). On the light-transmitting substrate21a, an indicating portion2ais provided three-dimensionally to be positioned around the liquid crystal display portion21bin accordance with the moving range of the pointer23, and a character portion2bis formed through cutting or the like.

The liquid crystal display portion21bis provided by sealing-in liquid crystal between a pair of light-transmitting substrates having a transparent electrode film formed thereon to provide a liquid crystal cell and then bonding a polarizing plate onto both surfaces of the liquid crystal cell. For example, a liquid crystal display of dot-matrix type is used. The liquid crystal display portion21bcan display variable contents and can selectively display various types of information such as a total driving distance, fuel economy, and alarm information.

The guide rail portion22is provided to surround the periphery of the liquid crystal display portion21bon the display plate21and is provided, for example, by forming light-transmitting resin into an arc shape as shown inFIG. 3. The guide rail portion22has a hollow portion22acapable of accommodating the pointer23and has a guide portion22bof hollow shape at its bottom portion where a regulating portion of a holding portion24, later described, is placed, as shown inFIG. 4. The guide rail portion22is covered with a decoration ring2cprovided on the front-face side of the display plate21such that a user cannot visually recognize the guide rail portion22.

As shown inFIGS. 2 and 4, the pointer23is made of light-transmitting resin such as polycarbonate, and is formed of a pointer base portion23a, one end portion of which is located in the guide rail portion22, and a pointing portion23bwhich is extended from the other end portion of the pointer base portion23aand points at the indicating portion2a. The pointer23is moved around the liquid crystal display portion21balong the guide rail portion22to point at the indicating portion2ato display predetermined information (vehicle speed in the present embodiment).

The holding portion24is made of light-shield resin material, for example ABS resin, and has a mounting portion24afor holding the pointer23movably along the guide rail portion22in the guide rail portion22and the regulating portion24bformed in the bottom portion of the mounting portion24a. The regulating portion24bis a protrusion portion which protrudes downward from the mounting portion24aand is placed in the guide portion22bprovided for the guide rail portion22and formed in the hollow shape conforming to the shape of the regulating portion24bto determine the position of the pointer23with reference to the guide rail portion22. It is also possible that the shapes of the regulating portion24band the guide portion22bcan be adjusted to determine the angle formed by the guide rail portion22and the pointer23at a predetermined angle.

A first magnet24cand a first yoke24dare located to be positioned around the pointer23in the mounting portion24aof the holding portion24. The first magnet24cand the first yoke24dmay be located directly on the pointer23.

The first magnet24cis located to be positioned around the pointer base portion23aaccommodated in the guide rail portion22. The first magnet24cand a second magnet25a, later described, attract each other.

The first yoke24dis provided closer to a surface of the first magnet24cthat is not opposite to the second magnet25a(the non-opposite surface). The first yoke24dconstitutes a magnet circuit which suppresses leakage flux from the non-opposite surface of the first magnet24cto improve the magnet efficiency.

The arm member25has the second magnet25aand a second yoke25bat one end and has the other end fitted to a rotation shaft26aof the stepping motor26. Pointer drive means in the present embodiment is formed of the arm member25and the stepping motor26.

The second magnet25ais placed at the position opposite to the first magnet24cwith the display plate21interposed between them to form a pair with the first magnet24c. The second magnet25amay be provided with a method in which the arm member25is formed by using resin material (for example, engineering plastic), the second magnet25ais formed by using a different member from the arm member25, and then insert molding or outsert molding is performed for integral formation, or with a method in which the arm member25is formed by using plastic magnet and the portion thereof opposite to the first magnet24cis magnetized.

The second yoke25bis provided closer to a surface of the second magnet25athat is not opposite to the first magnet24c(the non-opposite surface). The second yoke25bconstitutes a magnet circuit which suppresses leakage flux from the non-opposite surface of the second magnet25ato improve the magnet efficiency.

In the present embodiment, the first magnet24cis provided in the pointer23placed in the guide rail portion22, and the second magnet25ais provided in the arm member25secured to the rotation shaft26aof the stepping motor26such that the second magnet25ais opposite to the first magnet24cwith the display plate21interposed between them. Since the first magnet24cand the second magnet25aattract each other by the magnetic force, the pointer23can be moved along the guide rail portion22in association with the rotation drive of the stepping motor26. Therefore, even when the variable display portion is provided at the center of the display plate, the pointer is not increased in size or complicated due to the bypassing of the variable display portion as in the conventional method in which the pointer is directly secured to the stepping motor, so that the pointer23can be moved with excellent response.

In addition, the regulating portion24bwhich determines the position of the pointer23located on the guide rail portion22is provided for the holding portion24which holds the pointer23, and the guide portion22bconforming to the regulating portion24bis provided for the guide rail portion22. This can reduce displacement of the pointer23from the indicating portion2ato enable pointing at the indicating portion2awith high accuracy. Furthermore, the attraction force of the first and second magnets24c,25asupplies the holding portion24with a certain tension to the guide rail portion22, which can prevent small movements of the pointer23within the guide rail portion22to improve resistance to vibration.

For the shape of the regulating portion in the present invention, various shapes or members can be applied in addition to that in the first embodiment.

FIG. 5shows a second embodiment of the present invention. The second embodiment differs from the abovementioned first embodiment in that a regulating portion24eprovided for a holding portion24is formed of a roller member which rotates along a guide portion22bprovided for a guide rail portion22. The regulating portion24eformed of the roller member can suppress displacement of a pointer23and smoothly move the pointer23to improve response.

FIG. 6shows a third embodiment of the present invention. The third embodiment differs from the abovementioned first embodiment in that a regulating portion24fprovided for a holding portion24is formed of a ball member which rotates along a guide portion22bprovided for a guide rail portion22. The regulating portion24fformed of the ball member can suppress displacement of a pointer23and smoothly move the pointer23to improve response.

FIG. 7shows a fourth embodiment of the present invention. The fourth embodiment differs from the abovementioned first embodiment in that a regulating portion24gprovided for a holding portion24is formed of a linear protrusion portion which has an inclined surface, and in that a guide portion22cprovided for a guide rail portion22is formed of a V-shaped groove portion which has an inclined surface abutting on the regulating portion24g. The abutting inclined surface may be on any of left and right sides inFIG. 7. The abutment of the regulating portion24gand the guide portion22bwith the inclined surfaces can prevent small movements of the regulating portion24gwithin the guide portion22cto suppress displacement of a pointer23to improve resistance to vibration.

While the first and second magnets24c,25aare permanent magnets, the second magnet25amay be an electromagnet, for example. A display with an organic EL element may be used as the variable display element in addition to the liquid crystal display portion21b. While the stepping motor26is included as the pointer drive means, it goes without saying that a cross-coil movement may be used, for example, instead of the stepping motor26.

INDUSTRIAL APPLICABILITY

The present invention relates to an instrumental device and is preferable for an instrumental device which includes a variable display portion and a pointer moving around the variable display portion.