JP4676505B2 - Discharge lamp - Google Patents

Description

  The present invention relates to a discharge lamp.

In the energy saving era, the use of fluorescent lamps is becoming more popular in the lighting field, replacing the incandescent bulbs that have been generally used. Among fluorescent lamps, a bulb-type fluorescent lamp that has a high lamp efficiency and can be mounted using a socket for an incandescent bulb has become widespread.
The bulb-type fluorescent lamp has an arc tube attached to a holder and a printed board on which circuit components for driving the arc tube are mounted, and the printed board is housed in a case. An E-type base is attached to one end of the case.

In the arc tube, filament coil electrodes are sealed at both ends of the bent glass tube, and a phosphor layer is formed on the inner wall of the bent glass tube. And inside the arc tube, mercury Hg as a 253.7 nm ultraviolet radiation substance is sealed, and a rare gas such as argon Ar neon Ne is sealed as a buffer gas.
By the way, the radiation ultraviolet rays from mercury sealed in the arc tube depend on the mercury vapor pressure in the tube, and the start-up of the light beam is slow at the start-up under a low mercury vapor pressure state. In particular, it appears prominently under low temperature conditions.

In order to solve such a problem, a technique has been proposed in which a filament bulb is auxiliary arranged adjacent to the arc tube and the filament bulb is lit only for a certain period at the time of starting (for example, Patent Document 1). reference). The luminous flux emitted from the filament bulb raises the luminous flux of the entire lamp at the time of start-up to improve the start-up characteristics.
JP 2000-164174 A Japanese Unexamined Patent Publication No. 3-74002

The inventors of the present invention are working on the development of a bulb-type fluorescent lamp in which a luminous bulb is added to the arc tube to improve the luminous flux rising characteristics at the time of starting the lamp. In this development, with the aim of further improving the characteristics, the electrical input to the filament bulb is set to about twice as high as the electrical input to the arc tube.
Here, if the filament bulb can be normally lit only for a certain period at the start as expected, a satisfactory rise characteristic is obtained and a satisfactory result is obtained.

However, although it is extremely rare, it has been found that a timer circuit that turns off the filament light bulb by timing a certain period at the time of start-up may not operate normally due to defective electronic circuit components.
If the timer does not operate and the filament light bulb is lit for a long time, the heat generated by the filament light bulb (the heat generated due to the large electrical input) is transmitted to the case, and the case is deformed. The appearance may be damaged.

Further, as the lighting progresses, the printed board (printed wiring board) on which the electronic ballast and filament bulb circuit components are mounted becomes hot. For this reason, a phenomenon may occur in which a current path is formed in the insulating portion by sequentially causing dielectric breakdown between the high-voltage wiring and the low-voltage wiring of the printed board along the wiring pattern (this phenomenon is called “tracking phenomenon”). Conceivable.
The present invention has been made in view of the above-described problems. In a discharge lamp such as a light bulb-type fluorescent lamp, a light emitter such as a filament bulb is provided in the vicinity of the arc tube, and the light emitter is turned on for a certain period when it is turned on. Therefore, even if the timer circuit that measures the lighting-on / off timing of the light emitter does not operate normally, abnormal lighting can be stopped easily and reliably, making it safer. An object is to provide a discharge lamp.

  A discharge lamp according to the present invention comprises a light emitting tube that emits light by discharge, a light emitting body that is disposed in the vicinity of the light emitting tube and has higher luminous flux rise characteristics than the light emitting tube, and the light emitting tube and the light emitting body are turned on. A lighting unit including a lighting circuit to be turned off, and a timer circuit that turns off the light emitter after a predetermined time has elapsed from lighting; And a thermal fuse that cuts off energization.

Since the discharge lamp according to the present invention includes a thermal fuse that is blown by the heat of the light emitter, the heat generation of the light emitter that occurs when the timer circuit does not operate normally is detected by the thermal fuse, and the current supply to the lighting circuit is cut off. Thus, the light emitter can be turned off.
Also, a holding member that holds the arc tube and the luminous body, a printed board that is held by the holding member and has a component surface on which the operating circuit component that constitutes the lighting unit and the thermal fuse are mounted, May be provided.

Further, the arc tube and the light emitter may be located on a side opposite to the component surface of the printed board, and the thermal fuse may be disposed at a substantially central portion on the component surface. .
The operating circuit component is a power IC for power supply that constitutes the lighting unit, and the power IC is mounted on the component surface, and the IC pin of the power IC penetrates the printed board. The thermal fuse may be disposed close to the IC pin.

When the light emitter is disposed on the side opposite to the component surface, since the IC pins of the power IC penetrate the printed board, the heat on the opposite side is easily transmitted to the component surface side.
For this reason, according to this structure, since the heat of the IC pin of the power IC is quickly transmitted to the thermal fuse, the heat detectability of the light emitter is enhanced.
The operating circuit component is a choke coil that limits a current related to the lighting circuit, and the choke coil is mounted on the component surface in a state of being close to the power IC, and the temperature fuse May be sandwiched between the IC pin and the choke coil.

According to this configuration, heat of the current limiting choke coil that tends to generate heat during abnormal lighting is easily transmitted to the thermal fuse, which is preferable.
The light emitter may be a filament light bulb having a filament that generates heat and emits light.
Moreover, it is good also as providing the case which accommodates the said holding member and the said printed circuit board, and the nozzle | cap | die attached to the edge part of the said case.

In addition, the arc tube has a double spiral shape having a turning portion that spirally turns around a virtual axis in a state having a space on the inside, and the luminous body is the inner side of the arc tube. The space may be inserted in a state of being close to the outer wall of the arc tube.
The arc tube may be covered with a translucent glove.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, specific lamp specifications such as dimensions to be described are merely examples, and the present invention is not limited thereto.
1. Configuration of Light Bulb Fluorescent Lamp FIG. 1 is a cross-sectional view schematically showing a configuration of a light bulb shaped fluorescent lamp 1 according to an embodiment.
As shown in FIG. 1, a bulb-type fluorescent lamp 1 which is a kind of discharge lamp includes a double spiral arc tube 10, a holder 20 that is a holding member that holds the arc tube 10 at its end, and an arc tube 10. Are provided with an auxiliary light bulb 30, which is a light emitter disposed in a cylindrical space in the turn, a lighting unit 40 for lighting and driving the auxiliary light bulb 30, and a printed board 70.

The arc tube 10 has, for example, a rated power of 9 W and is used as an alternative to the incandescent bulb 60 W, and has a double spiral shape having a turning portion that turns around the virtual axis CL. The pipe outer diameter of the spiral shaped part is 7.5mm, the gap between the swirling parts swirling in the spiral (gap between the winding layers) is 2.0mm, the number of turns (number of winding layers) is about 6, and viewed from the virtual axis CL direction The outer diameter of the ring is 32.5 mm and the total length of the pipe is 60 mm.
The arc tube 10 has filament coil electrodes (inter-electrode distance of 530 mm) formed at both ends of the tube, and 3.0 mg of mercury Hg as a radiation substance having a wavelength of 253.7 nm is enclosed in the tube, and argon Ar, A mixed gas of krypton Kr (Ar80% + Kr20%) is sealed at a pressure of 550Pa.

The mercury to be encapsulated may be in the form of a substantially simple substance such as zinc mercury or tin mercury, even if it is not completely simple.
An auxiliary amalgam (not shown) is disposed near the electrode in the discharge space of the arc tube 10. The auxiliary amalgam improves luminous flux rise characteristics by releasing mercury when the lamp is started. A stainless mesh section plated with indium In is used for the metal body forming the auxiliary amalgam.

The auxiliary light bulb 30 is a filament light bulb provided with a cylindrical glass bulb 31 and a tungsten filament coil 32 housed in the glass bulb. The filament coil 32 is supported by a pair of stem lead wires 33 and 34.
The auxiliary light bulb 30 has a rated power of 20 W (twice that of the arc tube 10) and is inserted inside the arc tube 10 that turns. The outer wall of the glass bulb 31 of the auxiliary bulb 30 is close to the outer wall of the arc tube 10.

The glass bulb 31 is filled with 80 KPa of a mixed gas of krypton Kr—nitrogen N ₂ . The glass bulb 31 has a tube outer diameter of 16 mm and a tube length of 40 mm.
The auxiliary light bulb 30 has a higher (faster) luminous flux rising characteristic than the arc tube 10 and is lit only for a certain period when the lamp 1 is started, thereby improving the rising characteristic of the lamp 1.
The arc tube 10 and the auxiliary light bulb 30 are respectively inserted into insertion holes 20 provided in the holder, and are fixed on the back side of the holder 20 using silicone resin or the like.

The lighting unit 40 is composed of an inverter circuit based on a series inverter system or the like, and the circuit efficiency is about 90%. The tube input to the arc tube 10 is 10 × 0.9 = about 9 W.
The printed board 70 is made of glass / epoxy resin (heat-resistant temperature is about 150 ° C.), has a substantially circular shape, and has an outer diameter of about 38 mm. It is fixed by the holder 20.
In addition, most of the operation circuit components related to the lighting unit 40 are mounted on one component surface (the side opposite to the surface on the light emitting body 30 side) of the main outer layer surface of the printed board 70. Yes. The other solder side (solder side) is soldered to fix and electrically connect components on the component side.

The operation circuit component on the component surface is developed in the downward direction of the holder 20, and this operation circuit component is covered with the case 50.
A base 60 is attached to the lower end of the case 50.
A convex portion 10 a is formed at the apex portion of the arc tube 10.
The convex portion 10a is coupled to the globe 80 via a heat conductive medium 82 made of a transparent silicone resin. The convex portion 10 a becomes the coldest spot when the arc tube 10 emits light.

The globe 80 has translucency, and a diffusion film mainly composed of calcium carbonate is applied to the inner surface thereof.
2. Circuit Configuration FIG. 2 is a diagram illustrating a circuit configuration of the light bulb shaped fluorescent lamp 1 according to the embodiment.
As shown in FIG. 2, the lighting unit 40 of the bulb-type fluorescent lamp 1 receives power from a commercial power source and turns on the arc tube 10 and the auxiliary bulb 30, and includes a rectifier 41, a smoother 42, and a ballast 43. A preheating circuit 44, a timer circuit 46, and a thermal fuse 71.

On the power path from the commercial power source to the arc tube 10, a rectifier 41 that rectifies an alternating current supplied from the commercial power source, a smoother 42 that reduces pulsation in the current, and a stable control that controls lighting of the arc tube 10. The devices 43 are connected in this order.
The timer circuit 46 is a circuit that turns on the auxiliary light bulb 30 for a certain period, and includes resistors R11 to R14, capacitors (capacitors) C11 and C12, a Zener diode ZD, and transistor elements Q3 and Q4 as elements.

The operation of the timer circuit 46 is as follows.
(1) When the power source for the bulb-type fluorescent lamp 1 is turned on (when the lamp is started), the capacitor C11 is charged through the resistor R11. At the same time, a voltage is instantaneously applied between the GS (gate and source) of the transistor element Q3 via the resistors R12 and R14, the transistor element Q3 is turned on, and the auxiliary light bulb 30 is turned on.

(2) When the charging voltage of the capacitor C11 reaches the threshold voltage of the Zener diode ZD, the BE (base-emitter) of the transistor element Q4 is energized.
(3) When the transistor element Q4 is turned on by energization between the BEs of the transistor element Q4, the GS (gate-source) of the transistor element Q3 is short-circuited, and the auxiliary light bulb 30 is turned off.

In (1) to (3), the period from turning on to turning off the auxiliary bulb is set to about 60 seconds. This lighting-off period can be determined based on the rising state of the luminous flux of the main arc tube 10 and the necessity of the luminous flux assist effect by the auxiliary light bulb 30, and the specification and use of the lamp are assumed. Depending on the environment (for example, ambient temperature). The lighting-off period can be adjusted as appropriate by changing the resistance value of R11, the capacitance of C11, the applied voltage, and the like.
3. Luminous flux rise The effect of improving the luminous flux rise characteristic by providing the auxiliary bulb 30 in the above-described bulb-type fluorescent lamp 1 will be described.

FIG. 3 is a graph showing the results of examining the influence of the presence or absence of an auxiliary bulb on the rise of luminous flux at an ambient temperature of 5 ° C. under low temperature conditions.
The A line is a light flux transition of a conventional light bulb-type fluorescent lamp that does not include the auxiliary light bulb 30, and only about 10% of the light flux in a steady state is obtained immediately after starting.
B line | wire is a light beam transition of the lightbulb-type fluorescent lamp 1 which concerns on embodiment. Immediately after start-up, approximately 35% of the light flux in a steady state is obtained, and the rising characteristics are improved.

In B line, the luminous flux suddenly falls from about 65% to about 50% at 60 seconds because the auxiliary light bulb 30 is turned off. However, even when the auxiliary light bulb 30 is turned off, a higher luminous flux than that of the conventional light bulb-type fluorescent lamp indicated by line A is obtained.
Further, if a light flux of about 25% of the steady state is obtained at the time of starting the lamp, it is considered that the user who uses the lamp does not feel uncomfortable.

The C-line is a luminous flux transition of the same lamp except for the bulb-type fluorescent lamp 1 according to the embodiment and the auxiliary amalgam. When the B line and the C line are compared, the effect of improving the luminous flux rising characteristics by the auxiliary amalgam can be seen.
Thus, at the time of start-up, by supplementing the luminous flux of the arc tube 10 having a slow rise characteristic with the luminous flux of the auxiliary bulb 30 having a fast characteristic, the luminous bulb-type fluorescent lamp 1 as a whole can obtain a favorable luminous flux rise characteristic. .

However, it is assumed that the timer circuit does not operate normally due to defective circuit components as described above, and that the auxiliary light bulb 30 continues to be lit for a set time.
In the present embodiment, the thermal fuse 71 is provided on the printed board 70, and the energization in the lighting unit is cut off at the time of melting, thereby preventing a problem that may occur when the timer circuit does not operate. Next, an external configuration of the lighting unit 40 will be described with the temperature fuse 71 as a center.
4). Lighting Unit FIG. 4 is a perspective view of the lighting unit 40.

On the component surface 70a of the disk-shaped printed board 70, the operation circuit components constituting the lighting unit 40 are mounted.
The operation circuit parts include a power IC 74, smoothing capacitors 75 and 76, a resonance capacitor 77, and a choke coil 78 for current limiting.
The power IC 74 has a plurality of IC pins 74p on the left and right (in FIG. 4, four left and right are drawn).

A thermal fuse 71 (for example, a fusing temperature of 141 ° C.) covered with an insulating silicon tube 72 is disposed on the component surface 70a so as to be sandwiched between the power IC 74 and the choke coil 78. .
The thermal fuse 71 is disposed in proximity to or in contact with the IC pin 74p (in FIG. 4, the right IC pin 74p is blocked by the silicon tube 72 and cannot be seen). The proximity distance is 1 to 4 mm, preferably 3 mm.

Since the IC pin 74p penetrates the printed board 70, the thermal fuse easily transfers the heat on the solder surface 70b opposite to the component surface 70a to the component surface 70a side.
Because of this arrangement relationship, a heat transfer path can be established through the IC pin 74p, that is, the auxiliary light bulb 30 → the IC pin 74p → the temperature fuse 71.
The thermal fuse 71 is also disposed adjacent to the choke coil 78 mounted at the approximate center of the printed board 70.

Since the choke coil 78 is a heating element in the lighting unit 40, by making the temperature fuse 71 adjacent to the choke coil 78, the detectability of the temperature fuse 71 can be improved.
5. Thermal Fuse The arrangement position and fusing temperature of the thermal fuse 71 according to the embodiment are determined from the temperature measurement of the printed board 70. Next, this temperature measurement will be described.

FIG. 5A is a plan view of the lighting unit 40 when the printed board 70 is viewed from the solder surface 70b side.
As shown in FIG. 5A, in this temperature measurement, the light bulb shaped fluorescent lamp 1 is attached to an actual lamp and lit, and a central portion C point (Center) where the choke coil 78 of the printed board 70 is disposed, Temperature measurement was performed at two points of the peripheral portion V point (Verge, a location 5 mm inside from the plate periphery).

In this measurement,
Case A: When the timer circuit 46 that normally turns on and off the auxiliary light bulb 30 (the on / off time is set to about 30 seconds) is operated normally and the auxiliary light bulb 30 is turned on for about 30 seconds from the start of lighting,
Case B: When the auxiliary light bulb 30 is turned on endlessly without intentionally operating the timer circuit 46,
For the two cases A and B, the temperature after lighting for 30 minutes was measured. In case B, the thermal fuse 71 was removed from the printed board 70 because there was a risk that the temperature could not be measured because the fuse was blown when the thermal fuse 71 was placed.

FIG. 5B shows a table of measurement results.
As can be seen from this table, the temperature of case A in which the timer circuit 46 operates normally is as low as 120 ° C. at point C and 110 ° C. at point V, and normal lighting is maintained even after lighting for 30 minutes.
On the other hand, the temperature of Case B in which the timer circuit 46 was not operated was abnormally high at 166 ° C. at the C point and 145 ° C. at the V point.

In general, it is known that the tracking phenomenon in the printed board starts to occur when the substrate temperature becomes 160 ° C. or higher. In the case B, the temperature at the central point C is particularly high and tracking is likely to occur.
From this temperature measurement result, it can be said that a suitable position where the thermal fuse 71 is arranged on the component surface 70a is a substantially central portion of the printed board 70 that is likely to be hot.

The “substantially central portion” of the printed board 70 is a portion where components that are likely to be hot, such as the choke coil 78, are gathered. For example, the radius is approximately 70% or less of the radius of the circular printed board. Concentric circles.
Since the temperature at point C was 120 ° C. in case A and 166 ° C. in case B, if the fusing temperature of the thermal fuse 71 is set between 120 ° C. and 166 ° C., the occurrence of the tracking phenomenon will occur. It is possible to prevent the timer circuit from fusing unnecessarily when the timer circuit operates normally. From this point of view, the fusing temperature is set to 141 ° C. in the embodiment.
6). Others (1) In the above-described embodiment, the bulb-type fluorescent lamp 1 having a globe has been described. However, a type without a globe may be used.

FIG. 6 is a schematic diagram showing the configuration of the bulb-type fluorescent lamp 5.
The bulb-type fluorescent lamp 5 is a type without the globe 80 (FIG. 1). The effect similar to that of the embodiment can be obtained by arranging the auxiliary bulb 30 inwardly in the turning of the arc tube 15 and adopting the same configuration as the lighting unit 40 and the temperature fuse 71.
(2) In the above-described embodiment, the filament light bulb is described as an example of the auxiliary light bulb 30 that assists the luminous flux of the arc tube 10 at the time of starting. However, basically, the light beam rise characteristic can be improved in the same manner. Specifically, a krypton bulb, a KT krypton bulb, a high-intensity LED, or the like can be used as the light emitter.

However, it is preferable to employ a light bulb that easily generates heat, such as a filament light bulb, as the auxiliary light bulb. By arranging such an auxiliary bulb close to the arc tube, a significant effect can be obtained in that the inside of the arc tube is heated by heat conduction to increase the mercury vapor pressure and the luminous flux rise of the arc tube itself is improved. .
(3) In the above-described embodiment, the light bulb-type fluorescent lamp 1 having a double spiral-shaped arc tube has been described as an example. However, the present invention is a bent tube shape such as a U-shaped tube, a circular tube shape, The present invention can be applied to a lamp having a straight tube-shaped arc tube.

However, a lamp having a long discharge path length such as a double spiral arc tube can easily make use of the present invention because a delay in the rise of the luminous flux in a state where the outside air temperature is low is likely to appear.
(4) In the above-described embodiment, the printed circuit board 70 is horizontally placed (arranged in a direction substantially orthogonal to the virtual axis CL), but is not limited thereto, and is vertically arranged (arranged in a direction substantially parallel to the virtual axis CL). )
(5) In the above-described embodiment, the auxiliary light bulb 30 is turned on at the same time as the power is turned on. However, the auxiliary light bulb 30 may be turned on when the lamp 1 is started. Alternatively, the lighting may be started with a delay.

This is because a delay of this level makes it difficult for the user to notice the delay in the rise of the luminous flux and there is no practical problem.
(6) The present invention can be implemented as an illuminating device including the bulb-type fluorescent lamp 1 according to the embodiment. The lighting device refers to a combination of a discharge lamp and various appliances. The various instruments refer to, for example, reflecting mirrors, umbrellas, covers, sealing instruments, and the like.
(7) The configuration of the embodiment and the above-described configurations (1) to (6) can be implemented in combination.

  Since the discharge lamp according to the present invention has a good luminous flux rise characteristic, it can be suitably used for various discharge lamps.

1 is a cross-sectional view schematically showing a configuration of a bulb-type fluorescent lamp 1. FIG. 1 is a diagram showing a circuit configuration of a bulb-type fluorescent lamp 1. FIG. It is a figure which shows the graph of the result of having investigated the influence which the presence or absence of an auxiliary bulb has on luminous flux rise. 3 is a perspective view of a lighting unit 40. FIG. (A) is the top view which looked at the lighting unit 40 from the solder surface 70b side. (B) is a figure which shows the table | surface of a temperature measurement result. 2 is a cross-sectional view schematically showing a configuration of a bulb-type fluorescent lamp 5. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,5 Bulb-type fluorescent lamp 10 Arc tube 30 Auxiliary light bulb 40 Lighting unit 46 Timer circuit 60 Base 70 Printed board 70a Printed circuit board part surface 71 Thermal fuse 74 Power IC
74p IC pin

Claims (9)

An arc tube that emits light by discharge; and
A light emitter disposed in the vicinity of the arc tube and having a higher luminous flux rise characteristic than the arc tube;
A lighting unit including a lighting circuit for lighting the luminous tube and the luminous body, and a timer circuit for extinguishing the luminous body after a predetermined time has elapsed since lighting;
A thermal fuse that blows off due to the heat of the light emitter when the timer circuit does not operate normally and cuts off the power to the lighting circuit;
A discharge lamp comprising: A holding member for holding the arc tube and the luminous body;
A printed circuit board having a component surface that is held by the holding member and on which the operation circuit component constituting the lighting unit and the thermal fuse are mounted;
The discharge lamp according to claim 1, further comprising: The arc tube and the luminous body are located on the side opposite to the component surface of the printed board,
The discharge lamp according to claim 2, wherein the thermal fuse is disposed at a substantially central portion on the component surface. The operating circuit component is a power IC for power supply that constitutes the lighting unit,
The power IC is mounted on the component surface, and the IC pin of the power IC penetrates the printed board,
4. The discharge lamp according to claim 2, wherein the thermal fuse is disposed in proximity to the IC pin. The operating circuit component is a choke coil that limits a current related to the lighting circuit,
The choke coil is mounted on the component surface in a state close to the power IC,
The discharge lamp according to claim 4, wherein the thermal fuse is disposed between the IC pin and the choke coil. The discharge lamp according to claim 1, wherein the light emitter is a filament bulb including a filament that generates heat and emits light. A case for storing the holding member and the printed board;
The discharge lamp according to any one of claims 1 to 6, further comprising a base attached to an end of the case. The arc tube has a double spiral shape having a turning portion that spirally turns around a virtual axis in a state having a space inside,
The discharge lamp according to any one of claims 1 to 7, wherein the luminous body is inserted into the inner space of the arc tube in a state of being close to an outer wall of the arc tube. . The discharge lamp according to claim 8, wherein the arc tube is covered with a translucent globe.

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