JPH0612270B2 - Instrument guidelines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is characterized by applying high frequency power between electrodes.
It relates to the pointers of instruments that emit visible light.

[Prior Art] In recent years, in order to further improve the visibility of various instruments in adverse environments such as twilight, backlight, and high-speed running, it has been attempted to emit the pointer itself. As a guide, a self-luminous guide using a discharge lamp has been devised.
An example of a self-luminous indicator using this discharge lamp will be described with reference to FIG.

In a discharge lamp 100 serving as a guide, a discharge gas which is a rare gas such as argon or helium is enclosed in a hollow rod-shaped bulb 102 having a phosphor coating 101 formed on the inner surface.

An internal electrode 103, which is one of the electrodes, is provided near the end of the valve 102 (on the right side in FIG. 7), and the lead wire 104 of the internal electrode 103 is extended to the outer surface of the end of the valve 102. It is electrically connected to the main electrode 105 made of silver paste or the like applied to the outer surface of the end of the.

An external electrode 106, which is the other electrode formed by applying a conductive paste such as silver paste in a strip shape, is provided in the longitudinal direction of the outer surface of the bulb 102.

The outer surface of the valve 102, including the outer electrode 106, is
Since the slit-shaped light emitting display portion 107 is formed on the surface opposite to 06, a light shielding film 108 made of epoxy and carbon black is covered.

The pointer constructed in this way is used for the internal electrode 103 and the external electrode.
By applying high frequency power between 106 and the valve
Glow discharge occurs inside 102, and this glow discharge excites phosphor coating 101 to generate visible light. Then, visible light is emitted from the light emitting display unit 107 to the outside,
It indicates the display scale.

[Problems to be Solved by the Invention] However, according to the pointer having the above structure, for example, when an overvoltage is applied between the electrodes and a corona discharge occurs between the main electrode 105 and the external electrode 106, the corona discharge is generated. Since it has a function of carbonizing the organic matter, the light-shielding film 108 in the portion where the corona discharge is generated may be carbonized.

Therefore, the carbonized portion due to corona discharge gradually spreads,
When the carbonized portion is connected between the main electrode 105 and the external electrode 106, there is a problem that the electrode between the main electrode 105 and the external electrode 106 is likely to be short-circuited.

The present invention has been made based on the above circumstances, and an object thereof is to provide a guideline for an instrument that prevents a short circuit between electrodes when a corona discharge occurs between a main electrode and an external electrode. To do.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention is provided with a hollow rod-shaped bulb in which a phosphor coating is formed on an inner surface and discharge gas is sealed inside, and the bulb is provided inside the bulb. An internal electrode that is one of the electrodes, a main electrode that is provided on the outer surface of the bulb and is electrically connected to the internal electrode via a lead wire, and a main electrode that is provided along the outer surface longitudinal direction of the bulb. An external electrode, which is the other electrode, and a light-shielding coating made of an organic substance provided on the outer surface of the bulb, and a slit-shaped light emitting display section formed in the outer surface longitudinal direction of the bulb facing the outer electrode. By applying high frequency power between the inner electrode and the outer electrode,
As a technical means, in the pointer of an instrument for generating visible light in the bulb, the light-shielding film is not provided at least in a portion between the main electrode and the external electrode other than the light-emitting display section. adopt.

[Operation and Effect of the Invention] The guideline of the instrument of the present invention having the above-described configuration is that when forming the slit-shaped light emitting display unit, at least the interelectrode portion between the main electrode and the external electrode is provided in addition to the light emitting display unit. It was provided so as not to be covered with the light-shielding film.

Therefore, even if an overvoltage is applied between the main electrode and the external electrode and a corona discharge occurs between the main electrode and the external electrode, at least between the main electrode and the external electrode,
Since there is no organic light-shielding coating, carbonization due to corona discharge can be eliminated.

Therefore, even if an overvoltage is applied between the main electrode and the external electrode due to a circuit failure of the measuring instrument or the like, it is possible to prevent problems such as heat generation and melting without causing a short circuit between the electrodes.

[Embodiment] Next, the pointer of the instrument of the present invention will be described based on an embodiment shown in the drawings.

1 is a plan view of the pointer, FIG. 2 is a side sectional view of the pointer, and FIG. 3 is a rear view of the pointer.

The guideline 1 of the present embodiment is a self-luminous guideline 1 using a discharge lamp 2.
Then, for example, as shown in FIG. 6, it is used for a speedometer 1a of an automobile.

This discharge lamp 2 is formed of an elongated hollow rod-shaped glass bulb 3 having a weight of about 0.8 g, an outer diameter of 2.4 mm and a total length of 69 mm, and a phosphor coating 4 is provided on the inner surface thereof as shown in FIG. There is.

The glass bulb 3 has a hemispherical shell-shaped one end (left side in FIG. 1) which is the tip of the pointer 1, and a cylindrical middle portion. The other end of the pointer 1 on the rotation center side is sealed and solid, and has a narrow width portion 5 in which two opposing surfaces are formed in a concave shape and a power receiving portion 6 formed in a rectangular cross section.
And are formed.

Inside the glass bulb 3, 100 Torr of a discharge gas in which xenon and neon are mixed is sealed, and at the other end of the glass bulb 3, an internal electrode 7 which is one electrode is arranged. The internal electrode 7 is a lead wire 8 that is provided to hermetically penetrate the sealed solid portion of the glass bulb 3.
Through, is electrically connected to the main electrode 9 formed by applying a silver paste to the outer surface of the power receiving unit 6.

On the outer surface of the glass bulb 3 excluding the sealed solid part,
As shown in FIG. 3, an external electrode 10, which is the other electrode in a strip shape along the longitudinal direction, is provided. The external electrode 10 is formed by coating a conductive paste such as carbon phenol or silver epoxy on the bulb 3 and then firing the paste.

The external electrode 10 is 3.0 mm from the end face of the power receiving part 6 on the narrow part 5 side.
The glass bulb 3 is formed in a band shape from a position close to one end to one end of the glass bulb 3, and one end side is formed wide.
By forming the one end side wide, the electric field strength on the one end side in the glass bulb 3 increases, and the inner electrode 7 to the outer electrode 10
Since the electrons emitted toward the outside are made uniform over the entire outer electrode 10, the discharge lamp 2 can emit light with a uniform luminous intensity in the longitudinal direction.

On the outer surface of the glass bulb 3, there is a slit-shaped light-emitting display unit 11 that faces the external electrode 10 and is formed in the longitudinal direction of the outer surface of the glass bulb 3.
In order to form, a light-shielding coating 12 formed by mixing epoxy with carbon black is formed.

The light emitting display unit 11 is at a position facing the external electrode 10 by 180 degrees,
The glass bulb 3 has a width of 1.0 mm in the circumferential direction and a total length of 59 in the longitudinal direction.
It is formed to a size of 5 mm.

The light-shielding coating 12 that forms the light-emitting display portion 11 extends from the same position as the other end side of the external electrode 10 in the longitudinal direction to the tip portion (one end) of the glass bulb 3 from the upper portion of the external electrode 10 to the glass bulb 3. It is provided to cover.

Therefore, in addition to the light emitting display portion 11, the light shielding film 12 is formed on a part of the glass bulb 3 having a cylindrical shape from the other end and a solid portion including the narrow portion 5 and the power receiving portion 6. Absent. That is, the light-shielding coating 12 is not formed at least in the inter-electrode portion between the main electrode 9 and the external electrode 10.

The light emitting display unit 11 is formed by cutting off the light shielding film 12 formed on the outer surface of the glass bulb 3 by a predetermined size (width 1.0 mm, total length 59.5 mm).

At the position about 15 mm from the main electrode 9 of the glass bulb 3 to one end side,
As the power receiving portion 13 of the external electrode 10, an auxiliary electrode 14 formed by applying a silver paste, like the main electrode 9, is provided.

The auxiliary electrode 14 has a coating range of about 3 mm in the longitudinal direction, and is formed from both sides of the external electrode 10 toward the light emitting display section 11 side so as to cover the outer peripheral surface of the glass bulb 3 on which the light shielding coating 12 is formed. It is provided in the range of about 270 degrees on the circumference.

The pointer 1 configured as described above is the power receiving portion of the external electrode 10.
As shown in FIGS. 4 and 5, the auxiliary electrode 14 which is 13 and the main electrode 9 which is the power receiving portion 6 of the internal electrode 7 are
It is sandwiched by conductive power supply terminals 15 and 16 such as phosphor bronze, and high frequency power is applied to the main electrode 9 and the auxiliary electrode 14 via the power supply terminals 15 and 16.

The high frequency power applied to the main electrode 9 and the auxiliary electrode 14
By being supplied to the inner electrode 7 and the outer electrode 10, glow discharge is generated inside the glass bulb 3.

This glow discharge excites the phosphor coating 4 in the vicinity of the external electrode 10 to promote light emission, and this light emission is emitted to the outside from the light emitting display unit 11 formed on the glass bulb 3, and indicates the scale of the instrument.

In the self-luminous pointer 1 using such a discharge lamp 2, the main electrode
In some cases, an overvoltage is applied between the electrode 9 and the external electrode 10, corona discharge occurs between the main electrode 9 and the external electrode 10, and the corona discharge may carbonize the organic matter.

However, in the guideline 1 according to the present invention, the light-shielding coating 12 which is an organic substance is a solid part including the part from the other end of the cylindrical glass bulb 3, the narrow portion 5 and the power receiving portion 6 of the internal electrode 7. It is not formed in the part, and the main electrode 9 and the outer electrode 10
Since there is only the glass bulb 3 which is an inorganic material between and, the light-shielding coating 12 is not carbonized even when corona discharge occurs between the main electrode 9 and the external electrode 10.

Therefore, even if an overvoltage is applied between the main electrode 9 and the external electrode 10 due to a circuit failure of the instrument, the danger can be prevented without short-circuiting between the electrodes.

(Modification) In the present embodiment, the case where the light-shielding coating 12 is not formed on the power receiving portion 6 of the internal electrode 7 is illustrated, but in addition to the light emitting display portion 11, at least the space between the main electrode 9 and the external electrode 10 is provided. It is sufficient that the light-shielding coating 12 is not formed on the portion, and therefore the internal electrode 7
The light-shielding coating 12 may be formed on the power receiving portion 6 as well.

The guideline 1 of the present invention can be widely used as a guideline not only for speedometers of automobiles but also for various meters of airplanes, ships, etc., or measuring instruments of electric equipment.

[Brief description of drawings]

1 to 6 show one embodiment of the pointer of the instrument of the present invention. FIG. 1 is a plan view of the pointer, FIG. 2 is a side sectional view of the pointer, and FIG. 3 is a rear view of the pointer. 4 is a sectional view taken along the line AA of FIG. 1 including a power supply terminal, FIG. 5 is a sectional view taken along the line BB of FIG. 1 including a power supply terminal, and FIG. 6 is a pointer attached to an automobile speedometer. FIG. 7 is a state of use, and FIG. 7 is a partial cross-sectional view of the pointer according to the previous invention. In the figure, 3 ... Glass bulb, 4 ... Phosphor coating 7 ... Inner electrode, 9 ... Main electrode 10 ... External electrode, 11 ... Light emitting display section 12 ... Shading coating

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Hagisato 1 Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Yutaka Imai 1-cho, Toyota-cho, Aichi prefecture Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. A hollow rod-shaped bulb having a phosphor coating formed on the inner surface thereof and a discharge gas sealed therein, an inner electrode which is one of the electrodes provided inside the bulb, and the bulb and the outer surface. A main electrode that is provided and is electrically connected to the internal electrode via a lead wire, an external electrode that is the other electrode provided along the outer surface longitudinal direction of the bulb, and an outer surface of the bulb. A slit-shaped light emitting display portion formed in the longitudinal direction of the outer surface of the bulb facing the external electrode by a light-shielding coating made of an organic substance, and applying high-frequency power between the internal electrode and the external electrode. By doing so, in the pointer of the instrument for generating visible light in the bulb, the light-shielding coating is, in addition to the light-emitting display section, at least the electrode of the main electrode and the external electrode. Guidance of the instrument, characterized in that not provided in the portion.