JPH06300590A - Pointer illuminating instrument - Google Patents

Abstract

PURPOSE:To provide a transformer feed type pointer illuminating instrument which is compact and does not generate brightness fall of a light emitting element by connecting a thin conductive sheet of high magnetic permeability to it. CONSTITUTION:Alternating current power fed from a power source 7 to a primary coil 5 is transmitted to a secondary coil 6 by electromagnetic coupling, and fed from the oil 6 to a light emitting element 8 so as to emit a light. At this time, magnetic flux generated by the coil 5 is concentrated into a conductive sheet 9 of low magnetic path resistance, converged with sufficient intensity without generating eddy current loss, penetrated in the coil 6, and hence power is efficiently transmitted. The sheet 9 is provided on the boundary between the case of a pointer driving inner machine 4 and the coil 5, and hence it is perfectly separately intercepted between a magnetic circuit such as cross coil internally provided in the inner machine 4 and the magnetic circuit of the coil 5 so as not to interfere with each other. Hereby, efficient electric power transmission is furthermore guaranteed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pointer illuminating instrument for illuminating a pointer with a light emitting element, and more particularly to a pointer illuminating instrument for supplying power to a transformer to a light emitting element.

[0002]

2. Description of the Related Art In recent years, a transillumination type instrument has been widely used because of good visibility at night, and in such an instrument, pointer illumination for illuminating the pointer itself is performed.

The pointer illumination improves the visibility of the pointer by molding the main body of the pointer with a translucent acrylic resin or the like, bonding a light emitting element such as an EL element to the back surface of the main body, and supplying power to this to emit light. Is. A method using a spiral spring is generally used as a method for supplying power to the light-emitting element on the rotating pointer, but it requires space to install the spiral spring, and the load changes during rotation, so the pointer driving internal unit It is difficult to increase the size of the instrument and make it compact.

Therefore, the idea of transformer power feeding is disclosed in, for example, Japanese Utility Model Laid-Open No. 55-44263.
The outline thereof will be described with reference to FIG. 4. The light emitting element 8 provided on the rotating pointer is connected to the secondary coil 6 provided around the rotating shaft 2 at the base end of the pointer, while the primary coil 5 is provided on the panel side. It is provided and connected to the AC power supply 8. Then,
The AC power of the power source 8 is supplied to the light emitting element 8 in a non-contact manner via the transformer composed of the coils 5 and 6.

According to such a transformer power supply, the installation space is smaller than that when a spiral spring is used, the drive load fluctuation of the internal unit is also small, and the miniaturization of the instrument as a whole can be realized.

[0006]

However, when this transformer power feeding is put to practical use, there is a problem of interference with the internal unit that drives the pointer. That is, when the transformer coil is brought close to the internal unit for compactness, for example, when the internal unit case is a conductor (aluminum material, etc.), eddy current loss due to magnetic flux occurs and power transmission efficiency decreases, causing light emission. The brightness of the device decreases. In addition, since the inner unit case usually has a crossing coil, a stepping motor, etc. built therein, it may interfere with the magnetic fields of these crossing coils and the like, and the power transmission efficiency may also decrease.

Therefore, it is conceivable that the rotating shaft functioning as the transformer core is made of a material having high magnetic permeability, but it is often incompatible with the mechanical strength required for the rotating shaft.

An object of the present invention is to solve the above problems, and an object thereof is to provide a pointer-type lighting instrument of a transformer feeding type which is compact and which does not cause a decrease in the brightness of a light emitting element.

[0009]

The structure of the present invention will be described. A rotary shaft 2 provided upright on a panel plate 1, a pointer 3 having a base end 31 fixed to the distal end of the rotary shaft 2, and an input signal according to an input signal. Drive means 4 for driving the rotary shaft 2 so as to rotate the pointer 3 to a predetermined angle position, and the panel plate 1 around the rotary shaft 2.
Primary coil 5 provided on the side, a secondary coil 6 provided at the pointer base end 31 around the rotary shaft 2 so as to face the primary coil 5, and a power supply 7 for supplying AC power to the primary coil 5.
And a light emitting element 8 provided on the pointer 3 and connected to the secondary coil 6, and on the surface of at least one of the panel plate 1 side and the pointer base end 31 side in the magnetic path of the primary coil 5. And a conductor sheet 9 having a high magnetic permeability that is joined.

[0010]

In the above structure, the primary coil 5 and the secondary coil 6 constitute a transformer to transmit electric power by electromagnetic coupling. In this case, since the high-permeability conductor sheet 9 is provided in the magnetic path of the primary coil 5, the magnetic resistance is significantly reduced and the magnetic flux is concentrated in this portion. Therefore, even if the magnetic field interference occurs with the coils included in the driving means 4, since sufficient magnetic flux penetrates the secondary coil 6, the power transmission efficiency does not decrease.

Particularly, if the conductor sheet 9 is provided on the panel plate 1 side so as to partition the primary coil 5 and the driving means 4, the magnetic circuits of the transformer coils 5 and 6 and the magnetic circuit of the driving means 4 are completely separated. The power is cut off to enable more efficient power transfer.

Thus, even if the transformer coils 5 and 6 and the driving means 4 are provided close to each other, the power transmission efficiency does not decrease, and the overall size of the instrument is greatly reduced.

[0013]

[Embodiment 1] In FIG. 1, a pointer driving inner unit 4 as a driving means having a built-in cross coil and a stepping motor is provided on the back surface of the panel plate 1, and its rotary shaft 2 has an opening 11 in the panel plate 1. It projects upward through it. Rotating shaft 2
A base end 31 of a pointer 3 made of a translucent resin such as acrylic resin extending horizontally along the panel plate 1 is fitted and fixed to the projecting end of the pointer 3, and the lower surface (back surface) of the pointer 3 is fixed to the base end 31. A flat plate-shaped EL light emitting element 8 is joined along it.

The light emitting element 8 has a lead wire (not shown)
It is connected to a secondary coil 6 provided around the rotary shaft 2 on the lower surface of the base end 31 of the pointer 3. A primary coil 5 that constitutes a transformer with the secondary coil 6 is concentrically provided outside the secondary coil 6 at a constant interval, and the coil 5 is fixed on the case of the internal unit 4 facing the panel opening 11. Has been done. This coil 5
In the case of the inner unit case where is provided, amorphous, steel sheet or the like having a high magnetic permeability is thin in a range wider than the panel opening 11 (20 to 3).
The conductor sheet 9 is joined.

The AC power source 7 is provided outside the internal unit 4,
It is connected to the primary coil 5 by a lead wire 71.

In the above structure, the AC power supplied from the power source 7 to the primary coil 5 is electromagnetically coupled to the secondary coil 6.
And is supplied to the light emitting element 8 from the secondary coil 6 to cause it to emit light. At this time, the magnetic flux generated by the primary coil 5 is concentrated on the conductor sheet 9 having a low magnetic path resistance, is converged with sufficient strength without causing eddy current loss, and penetrates the secondary coil 6 to improve efficiency. Power is transmitted.

Since the conductor sheet 9 is provided at the boundary between the case of the inner unit 4 and the primary coil 5, the magnetic circuit such as a cross coil built in the inner unit and the magnetic circuit of the primary coil 5 are completely separated. They are blocked and do not interfere with each other. This also ensures more efficient power transfer.

[0018]

[Embodiment 2] If there is no space limitation in the vertical direction, the arrangement of the primary coil 5 and the secondary coil 6 may be such that they are vertically opposed to each other as shown in FIG.
It is more advantageous in terms of electric power transmission efficiency than the case of facing the inside and outside as in the above.

[0019]

[Embodiment 3] When it is difficult to provide the conductor sheet 9 on the case surface of the inner unit 4, it may be provided between the secondary coil 6 and the lower surface of the pointer base end 31 as shown in FIG. Also in this case, the magnetic flux is made to converge on the conductor sheet 9 and sufficient magnetic flux penetrates the secondary coil 6, thus realizing efficient power transmission.

[0020]

As described above, according to the pointer illuminating instrument of the present invention, the transformer coil is provided sufficiently close to the inner unit as the driving means by the simple structure for joining the thin conductive sheets having high magnetic permeability. Efficient power transfer is guaranteed, and it is possible to realize a compact instrument with excellent pointer visibility.

[Brief description of drawings]

FIG. 1 is a side sectional view of a main part of a pointer lighting instrument according to a first embodiment of the present invention.

FIG. 2 is a sectional side view of a main part of a pointer lighting instrument according to a second embodiment of the present invention.

FIG. 3 is a side sectional view of a main part of a pointer lighting instrument according to a third embodiment of the present invention.

FIG. 4 is an electrical system diagram of a pointer lighting instrument.

[Explanation of symbols]

 1 Panel Plate 2 Rotating Shaft 3 Pointer 4 Internal Machine (Driving Means) 5 Primary Coil 6 Secondary Coil 7 Power Supply 8 Light Emitting Element 9 Conductor Sheet

Claims (1)

[Claims] 1. A rotary shaft erected on a panel plate, a pointer having a base end fixed to the rotary shaft, and a drive means for driving the rotary shaft to rotate the pointer to a predetermined angle position according to an input signal. And a primary coil provided on the panel plate side around the rotation axis, a secondary coil provided at the pointer base end around the rotation axis so as to face the primary coil, and a power supply for supplying AC power to the primary coil. And a light-emitting element provided on the pointer and connected to the secondary coil, and a high magnetic permeability that is bonded to at least one of the panel plate side and the pointer base end side in the magnetic path of the primary coil. Illumination meter with a conductor sheet of.