JP4210180B2 - Incandescent lamp - Google Patents

Description

  The present invention relates to an incandescent lamp, and more particularly to an incandescent lamp suitably used as a light source of a lighting device for studio lighting and stage lighting, for example.

As lighting devices for TV studio lighting and stage lighting, those using an incandescent lamp as a light source are widely used.
Conventionally, an incandescent lamp has a configuration in which a single filament is disposed inside an arc tube. According to such an incandescent lamp, dimming that adjusts the amount of light by controlling supply power. However, since the obtained color temperature changes as the supplied power changes, for example, a state where a constant color temperature (3200K) required for the problem of sensitivity of the TV camera is maintained is maintained. Therefore, it is difficult to change only the light quantity at a large change rate.

  Thus, in the field where it is necessary to produce with light, a plurality of lighting devices having incandescent lamps having the same color temperature characteristics and different rated power consumption are prepared. The amount of light is adjusted in a state where a constant color temperature is maintained by switching between the two or more lighting devices or simultaneously operating two or more lighting devices to superimpose light.

However, in the case of using a plurality of lighting devices, these lighting devices must be appropriately operated or paused, and there is a problem that the operation becomes complicated, so to solve this problem, There has been proposed an illuminating device including an incandescent lamp having a configuration in which a plurality of filaments having equivalent color temperature characteristics and different rated power consumption are arranged inside an arc tube (for example, Patent Document 1). To Patent Document 3).
According to an illuminating device including such an incandescent lamp, one of a plurality of filaments can be appropriately selected to be in a lighting state without using a plurality of illuminating devices, or two or more filaments can be turned on. By simultaneously superimposing light as a lighting state, the light amount can be adjusted while maintaining a constant color temperature.

JP 2002-093588 A JP 2001-143880 A Registered Utility Model No. 3008927

  As incandescent lamps used in these lighting devices, as shown in FIGS. 10 to 12, inside the arc tube 61, on the same virtual plane (hereinafter also referred to as “first virtual plane”). A first filament 71 composed of a plurality (four in the figure) of filament segments (hereinafter also referred to as “first segments”) 71A arranged in parallel and connected in series via a toe portion 71B; The same number (four) as the number of first segments that are arranged in parallel on the same virtual plane parallel to the virtual plane (hereinafter also referred to as “second virtual plane”) and connected in series via the toe portion 75B. The second filament 75 made of a filament segment (hereinafter also referred to as “second segment”) 75 </ b> A is disposed to oppose the tube axis of the arc tube 61, and the first segment 71 </ b> A and the second segment 5A and 5A are alternately arranged on the projection plane in a direction parallel to the first virtual plane and the second virtual plane (hereinafter also referred to as “specific parallel projection plane”). .

In the incandescent lamp 60, the first filament 71 is connected to a common internal lead bar 63A at one end thereof, and is connected to the first filament internal lead rod 63B at the other end thereof. A common internal lead bar 63A is connected to one end of the second filament 75, and a second filament internal lead bar 63C is connected to the other end, and the first filament 71 and the second filament 75 are connected to each other. Each filament 75 is individually supplied with a predetermined amount of supply power.
In the figure, 65A and 65B are glass pieces mounted and held on the common internal lead bar 63A and the first filament internal lead bar 63B or the second filament internal lead bar 63C, respectively. 66B is an anchor for locking the toe portions 71B and 75B, one end of which is supported by the glass pieces 65A and 65B, and 69 is a socket to which the incandescent lamp 60 is attached.
In FIGS. 10 and 11, the first segment 71A and the second segment 75A are shown with different patterns. Furthermore, in FIG. 12, the alternate long and short dash line M3 indicates a cross section of the first imaginary plane, the alternate long and short dash line M4 indicates a cross section of the second imaginary plane, the point C2 indicates the tube axis position of the arc tube 61, and The center line of the arc tube in the LL cross section is indicated by a two-dot chain line.

  However, the incandescent lamp having such a configuration reflects the incandescent lamp particularly because the arrangement position of each segment is designed based on the operation state in which all the filaments arranged inside the arc tube are in the lighting state. When used in combination with a mirror, the center of the light emitting surface formed by the filament in the lit state does not exist on the optical axis of the reflector in the operating state in which only one filament is lit. However, there is a problem that the light distribution characteristics of the reflecting mirror cannot be fully utilized, resulting in uneven light distribution on the irradiated surface.

  The present invention has been made based on the circumstances as described above, and the purpose thereof is to obtain high light emission performance even when used in combination with a reflecting mirror, and in any operating state. An object of the present invention is to provide an incandescent lamp in which the occurrence of uneven light distribution is suppressed.

In the incandescent lamp of the present invention, a first filament composed of a plurality of filament segments arranged in parallel on the same virtual plane and a filament segment constituting the first filament are arranged in parallel inside the arc tube. A second filament composed of a plurality of filament segments arranged in parallel on the same virtual plane parallel to the plane is arranged to face each other, and power is individually supplied to each of the first filament and the second filament. In the incandescent lamp, the first filament has an even number of filament segments, the second filament has an odd number of filament segments, and the filament segments constituting the first filament; Filament segment constituting the second filament DOO is placed in different positions on the projection plane in the direction parallel to the virtual plane in which these filaments segments are parallel,
Each of the filament segment constituting the first filament and the filament segment constituting the second filament includes the tube axis of the arc tube, and is disposed symmetrically with respect to a plane perpendicular to the virtual plane in which the filament segments are juxtaposed. It is characterized by.

In the incandescent lamp according to the present invention, each of the first filament and the second filament is perpendicular to a virtual plane in which the filament segment constituting the first filament and the filament segment constituting the second filament are arranged in parallel. On the projection plane in a certain direction, a contact is made at a position facing each other of each of the two filament segments constituting the other filament that passes through the center of one filament segment constituting the one filament and is adjacent to the filament segment. It is preferable that the angle formed by the two tangents having the above is 30 ° or more.
In such an incandescent lamp, the first filament and the second filament in a direction perpendicular to a virtual plane in which the filament segments constituting the first filament and the filament segments constituting the second filament are arranged in parallel Is preferably 0.5 mm or more.

  In the incandescent lamp of the present invention, the first filament and the second filament preferably have different rated power consumption values.

According to the incandescent lamp of the present invention, even when used in combination with a reflecting mirror, the even number of first segments constituting the first filament and the odd number of second segments constituting the second filament. Are arranged at different positions on the specific parallel projection plane, so that most of the light emitted from the filament located behind the light projection direction is located in front of the light projection direction. Therefore, the light emitted from each filament can be utilized with high efficiency, and the first filament or the second filament can be used. In any operating state when only one is lit or both are lit, the filaments that are lit Since the position of each filament segment can be designed so that the central axis of the light emitting surface formed is on the optical axis of the reflector, the light distribution characteristics of the reflector can be fully utilized in any operating state can do.
Therefore, according to the incandescent lamp of the present invention, even when used in combination with a reflecting mirror, high light emission performance can be obtained and the occurrence of uneven light distribution can be suppressed in any operating state.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is an explanatory front view showing an example of the configuration of the incandescent lamp of the present invention, FIG. 2 is a side view for explaining the incandescent lamp of FIG. 1, and FIG. 3 shows the incandescent lamp of FIG. It is LL sectional drawing of the incandescent lamp of the said FIG. 1 which shows the arrangement | positioning state of the filament segment to comprise. 4 is an explanatory diagram showing an enlarged configuration of the first filament constituting the incandescent lamp of FIG. 1, and FIG. 5 is an enlarged diagram of the second filament constituting the incandescent lamp of FIG. It is explanatory drawing shown.
The incandescent lamp 10 includes a light-emitting tube 11 made of, for example, hard glass, having a sealing portion 12 having an airtight sealing portion formed by a pinch seal at one end and an exhaust pipe remaining portion 13 at the other end. Inside the arc tube 11, an even number (four in FIG. 1) of filament segments (4 in FIG. 1) arranged in parallel on the same virtual plane (hereinafter also referred to as “first virtual plane”) parallel to the pinch seal surface. Hereinafter, also referred to as “first segment.”) The first filament 30 made of 33 and the same virtual plane parallel to the first virtual plane (hereinafter also referred to as “second virtual plane”) are arranged in parallel. The second filament 40 consisting of an odd number (three in FIG. 1) of filament segments (hereinafter also referred to as “second segments”) 43 is the first filament 30 and the second filament 40, respectively. Such that each filament segment 33, 43 constituting extends along the tube axis of the arc tube 11 are oppositely arranged through the tube axis of the arc tube 11. The incandescent lamp 10 is attached to the socket 19.
1 and 2, each of the first segment 33 and the second segment 43 is shown with different patterns. In FIG. 3, the alternate long and short dash line M <b> 1 indicates a cross section of the first imaginary plane, the alternate long and short dash line M <b> 2 indicates a cross section of the second imaginary plane, and the point C <b> 1 indicates the tube axis position of the arc tube 11.

  Each of the first segments 33 constituting the first filament 30 has the same shape, for example, a filament wire made of tungsten is wound in a coil shape, and its axis is on the first virtual plane. The other first segments 33 that are arranged at equal intervals so as to be present at each other and are connected in series via the U-shaped upper toe portion 34A or the lower toe portion 34B.

  A common internal lead bar 21 is connected to one end of the first filament 30 and a first filament internal lead bar 22 is connected to the other end of the first filament 30. Each of the filament internal lead rods 22 extends to the sealing portion 12 and is connected to metal foils 16A and 16C embedded in the sealing portion 12 so as to be separated from each other.

  The first filament 30 is supported by the glass piece 15 in which each of the upper toe portions 34A is attached to and held by one end of the common internal lead bar 21 and the first filament internal lead bar 22. The lower filament portion 34B is locked by the first filament short-axis anchor 26B, one end of which is supported by the glass piece 15. Thus, it is arranged at a desired position inside the arc tube 11.

  Each of the second segments 43 constituting the second filament 40 has the same shape, for example, a filament wire made of tungsten is wound in a coil shape, and its axis is on the second imaginary plane. The other second segments 43 that are arranged at equal intervals and are adjacent to each other are connected in series via a U-shaped upper toe portion 44A or a lower toe portion 44B.

  A common internal lead bar 21 is connected to one end of the second filament 40 via a connecting internal lead bar 24 and a connecting member 25 supported by a glass piece 15, and the other end is connected to the second filament 40. A second filament internal lead rod 23 is connected. The second filament internal lead rod 23 extends to the sealing portion 12 and is connected to the metal foil 16B embedded in the sealing portion 12 so as to be separated from each of the metal foils 16A and 16C.

  In addition, the second filament 40 has an upper portion 44A that is locked by a second filament long-axis anchor 27A supported at one end by the glass piece 15, and a lower portion 44B that has a lower portion 44B. One end is locked by a short filament anchor 27B for the second filament supported by the glass piece 15, and is arranged at a desired position inside the arc tube 11.

And the 1st segment 33 which constitutes the 1st filament 30, and the 2nd segment 43 which constitutes the 2nd filament 40 are projection surfaces (henceforth, the direction parallel to the 1st virtual surface and the 2nd virtual surface below). It is also referred to as “specific parallel projection plane”).
In the example of this figure, the four first segments 33 and the three second segments 43 each include the tube axis of the arc tube 11 and are planes perpendicular to the first virtual plane and the second virtual plane. (Hereinafter, also referred to as “specific symmetry plane”) (symmetric in FIG. 3), and one second segment 43 is provided between the first segments 33 adjacent to each other on the specific parallel projection plane. On the other hand, the first segments 33 are alternately arranged between the second segments 43 adjacent to each other.

Further, each of the first filament 30 and the second filament 40 is one filament on a projection plane perpendicular to the first imaginary plane and the second imaginary plane (hereinafter also referred to as “specific vertical projection plane”). The angle formed by two tangents (hereinafter referred to as the two tangents) having a contact at a position facing each other of each of the two filament segments constituting the other filament closest to the filament segment. , Also referred to as “specific angle”) is preferably arranged so that the angle is 30 ° or more.

The specific angle will be described with a specific example. As shown in FIG. 6, one of the four first segments 33A, 33B, 33C, 33D in the first filament 30 and the first segment 33C In the relationship with the second segments 43B and 43C adjacent to the first segment 33C among the three second segments 43A, 43B and 43C in the second filament 40, the center point T1 of the first segment 33C is The tangent line N1 that forms the contact point S1 located on the second segment 43C side in the second segment 43B and the tangent line that forms the contact point S2 located on the second segment 43B side in the second segment 43C through the center point T1 An angle A1 formed by N2 indicates a specific angle.
Further, in the relationship between one second segment 43A in the second filament 40 and the first segments 33A and 33B adjacent to the second segment 43A in the first filament 30, the center point T2 of the second segment 43A And the tangent line N3 forming the contact S3 located on the first segment 33B side in the first segment 33A and the contact S4 located on the first segment 33A side in the first segment 33B through the center point T2 are formed. An angle formed by an angle A2 formed with the tangent line N4 is shown.

  When the specific angle is too small, the light emitted forward from the filament in the light projecting direction in the operation state in which one filament located behind the light projecting direction is turned on in relation to the irradiated surface. Since the ratio blocked by the filament segment constituting the other filament increases, the light emitted from the filament cannot be used with high efficiency as the entire incandescent lamp 10, and as a result, high light is applied to the incandescent lamp 10. Radiation performance may not be obtained.

In particular, when the specific angle is 30 ° or more, the first segment in the direction perpendicular to the virtual plane in which the filament segments constituting the first filament and the filament segments constituting the second filament are juxtaposed are arranged . The separation distance between the filament 30 and the second filament 40 (hereinafter also referred to as “specific separation distance”) B (see FIG. 6) is preferably 0.5 mm or more, particularly 0.5 to 4 mm. Preferably there is.
When the specific separation distance B is too small, the first filament 30 and the second filament 40 are very close to each other, so that a discharge or discharge is generated between the first filament 30 and the second filament 40. There is a possibility that a short circuit occurs and instantaneous fusing occurs due to this, and the incandescent lamp 10 cannot have a long service life.

According to the incandescent lamp 10 having the above configuration, for example, as shown in FIG. 2 and FIG. 3, the cross-section is combined with a reflecting mirror arranged in a state represented by a broken line H in relation to the incandescent lamp 10. Even if it is used, the four first segments 33 constituting the first filament 30 and the three second segments 43 constituting the second filament 40 are alternately arranged on the specific parallel projection plane. Most of the light emitted from the filament (first filament 30 in the figure) located in the rear of the light projection direction is located in front of the light projection direction. Since it is projected to the outside of the arc tube 11 without being interrupted by the filament (second filament 40 in the figure), it is released from each filament 30, 40. Can be utilized with high efficiency, and in either of the operating states when only one of the first filament 30 and the second filament 40 is in the lit state or when both are lit. The filament segments are arranged so that the configuration of the filaments 30 and 40 is symmetric with respect to the specific symmetry plane so that the central axis of the light emitting surface formed by the filament in the lit state is located on the optical axis of the reflector Since the position can be designed, the light distribution characteristics of the reflecting mirror can be fully utilized.
Therefore, according to the incandescent lamp 10, even when used in combination with a reflecting mirror, high light emission performance can be obtained, and the occurrence of uneven light distribution can be suppressed in any operating state.

  Here, from the viewpoint of utilization, the reflecting mirror is preferably disposed at the rear position of the first filament and the filament having a large number of segments among the second filaments as shown in FIGS. .

  Further, in the incandescent lamp 10, the first segment 33 and the second segment 43 are arranged in a state where the specific angle is 30 ° or more and the specific separation distance is 0.5 mm or more. The light emitted from each of the first filament 30 and the second filament 40 is surely used with high efficiency, and instantaneous fusing occurs in the first filament 30 and the second filament 40 in the operating state. Therefore, it is possible to obtain a higher light emission performance and a longer service life.

  In the incandescent lamp 10 having such a configuration, the first filament and the second filament have equivalent color temperature characteristics and have different rated power consumption, so that the operation state thereof is Only the amount of light can be changed at a large rate without changing the color temperature obtained by the change. Therefore, according to such an incandescent lamp, it is possible to perform light control while maintaining a constant color temperature.

  As described above, even when the incandescent lamp is used in combination with a reflecting mirror, high light emission performance can be obtained and the occurrence of uneven light distribution can be suppressed in any operating state. Therefore, a light source that is preferably used as a light source for illumination and that has a filament temperature that has particularly equivalent color temperature characteristics and different rated power consumption is maintained in a state where a constant color temperature is maintained. Since dimming can be performed, the light source is suitably used as a light source of a lighting device for studio lighting and stage lighting.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, the incandescent lamp is composed of n first filaments (n is an even number) first segment, and the second filament is composed of (n-1) second segments. The number of first segments and the number of second segments may be large, and the difference between the number of first segments and the number of second segments is one or more. May be.
The incandescent lamp is limited to a lamp having a configuration in which the first segment constituting the first filament and the second segment constituting the second filament are alternately arranged on the specific parallel projection plane. What is necessary is just to have the structure by which these filament segments are arrange | positioned in a different position.

  Hereinafter, experimental examples performed for confirming the effects of the present invention will be described.

[Experimental Example 1]
Various kinds of experimental incandescent lamps were produced in which the specific angle was changed within the range of 10 to 120 ° according to the configuration of FIG.
For each of the experimental incandescent lamps produced, only the second filament was turned on, and the irradiation surface distance on the plane parallel to the first imaginary plane and the second imaginary plane located on the first filament side was ± 50 mm. The distribution of the amount of light in the irradiation region (hereinafter also referred to as “irradiation measurement region”) was measured with an illuminometer. FIG. 7 shows the maximum light amount value and the minimum light amount value in the irradiation measurement region when the light amount actually requested in such an operation state (hereinafter also referred to as “request value”) is 100%. Indicated by relative value.

  From the above results, by setting the specific angle to be 30 ° or more, the maximum light quantity is 90% or more with respect to the required value, the minimum light quantity value is 85% or more with respect to the required value, and the maximum light quantity value. It was confirmed that the light quantity condition required for practical use in which the difference between the minimum light quantity value and the minimum light quantity value is within 20% is sufficiently satisfied.

[Experiment 2]
In accordance with the configuration shown in FIG. 1, various incandescent lamps for experiments were manufactured in which the specific angle was set to 30 ° or more and the specific separation distance was changed within a range of 0.25 to 4 mm.
For each of the experimental incandescent lamps produced, both the first filament and the second filament were continuously turned on, and the continuous operation time from when lighting was started until one of them was turned off was measured. . The results are shown in FIG.

  From the above results, it was confirmed that a long service life with a continuous operation time of 300 hours or more can be obtained by setting the specific separation distance to 0.5 mm or more.

[Experimental Example 3]
Among the experimental incandescent lamps produced in Experimental Example 2, those having a specific separation distance of 0.5 mm, 1.8 mm, 2.8 mm, and 4 mm were used. Only the filament was turned on, and the distribution of the amount of light in the irradiation measurement region located on the first filament side was measured with an illuminometer. FIG. 9 shows a light distribution map showing the measured light quantity as a relative value when the required value is 100%. FIG. 9 shows the light distribution of an incandescent lamp having a configuration in which only one filament composed of four segments arranged in parallel on the same virtual plane is arranged on a plane including the tube axis of the arc tube. Also shown.
In FIG. 9, curve A shows the measurement result when the specific separation distance is 0.5 mm, curve B shows the measurement result when the specific separation distance is 1.8 mm, and curve C shows the measurement result when the specific separation distance is 2 mm. The measurement result when .8 mm is shown, and curve D shows the measurement result when the specific separation distance is 4 mm. Curve H shows the light distribution of an incandescent lamp having a configuration in which only one filament is arranged on a plane including the tube axis of the arc tube.

  From the above results, as the specific separation distance increases, the amount of light in the irradiation measurement region decreases as a whole, and the unevenness of the light distribution curve due to the influence of the first filament located in front of the light projection direction tends to increase. However, when the specific separation distance is within the range of 0.5 to 4 mm, the maximum light amount is 90% or more of the required value, the minimum light amount value is 85% or more of the required value, and the maximum It was confirmed that the practically required light quantity condition that the difference between the light quantity value and the minimum light quantity value is within 20% is sufficiently satisfied.

  In accordance with the configuration of FIG. 1, a tungsten filament having a wire diameter of 0.23 mm is wound in a coil shape, a first filament consisting of four segments having an outer diameter of 1.3 mm and a total length of 15 mm, and a wire diameter of 0.16 mm An incandescent lamp with a maximum power consumption of 1000 W, in which a second filament made of three segments having an outer diameter of 0.9 mm and a total length of 12 mm is opposed to the inside of the arc tube. (Hereinafter also referred to as “incandescent lamp (1)”) was produced. The specifications of the first filament and the second filament constituting the incandescent lamp (1) are shown in Table 1 below.

  The produced incandescent lamp (1) is combined with a reflecting mirror arranged in a state where the cross section is represented by a broken line H in relation to the incandescent lamp (1) as shown in FIGS. The operating state of the incandescent lamp is as follows: (a) when both the first filament and the second filament are lit, (b) when only the first filament is lit, (c) second In each of the cases where only the filament was turned on, the light distribution state on the irradiated surface with an irradiation surface distance of ± 50 mm was confirmed by a method of measuring the illuminance with an illuminometer and calculating the relative value of the measured values. However, light distribution unevenness which is a problem in practical use has not occurred in any of the operation states.

  In addition, when the color temperature was measured with a color thermometer in the operation states (a) to (b), it was confirmed that a color temperature of 3200 K was obtained in any operation state where the obtained light amount was different.

  Further, in the incandescent lamp (1), only one of the filaments is continuously turned on, and each of the first filament and the second filament from the start of lighting in this operation state to the turn-off state continues. The lighting time was measured. The results are shown in Table 1 below.

  In accordance with the configuration of FIG. 1, a tungsten filament having a wire diameter of 0.20 mm is wound into a coil, a first filament consisting of four segments having an outer diameter of 1.2 mm and a total length of 14 mm, and a wire diameter of 0.20 mm An incandescent lamp with a maximum power consumption of 1000 W, in which a second filament composed of three segments having an outer diameter of 1.18 mm and a total length of 12 mm, which is wound in a coil shape, is placed inside the arc tube. Hereinafter, it was also referred to as “incandescent lamp (2)”. The specifications of the first filament and the second filament constituting the incandescent lamp (2) are shown in Table 1 below.

The light distribution state on the irradiated surface was confirmed by the same method as in Example 1 except that the produced incandescent lamp (2) was used in place of the incandescent lamp (1). There was no uneven light distribution as a problem.
Further, when the color temperature in each operation state was measured by the same method as in Example 1, it was confirmed that a color temperature of 3200 K was obtained in any operation state.
Further, the continuous operation time of the first filament and the second filament constituting the incandescent lamp (2) was measured by the same method as in Example 1. The results are shown in Table 1 below.

It is an explanatory front view which shows an example of a structure of the incandescent lamp of this invention. It is a side view for description of the incandescent lamp of FIG. It is LL sectional drawing of the said incandescent lamp of the said FIG. 1 which shows the arrangement | positioning state of the filament segment which comprises the incandescent lamp of FIG. It is explanatory drawing which expands and shows the structure of the 1st filament which comprises the incandescent lamp of FIG. It is explanatory drawing which expands and shows the structure of the 2nd filament which comprises the incandescent lamp of FIG. It is explanatory drawing which shows the arrangement | positioning state of the 1st filament which comprises the incandescent lamp of FIG. 1, and a 2nd filament. It is a figure which shows the relationship between the specific angle which concerns on Experimental example 1, and a light quantity value. It is a figure which shows the relationship between the specific separation distance which concerns on Experimental example 2, and continuous operation time. It is a light distribution map concerning Experimental Example 3. It is a front view for description which shows an example of a structure of the conventional incandescent lamp. It is a side view for description of the incandescent lamp of FIG. It is LL sectional drawing of the said incandescent lamp of the said FIG. 10 which shows the arrangement | positioning state of the filament segment which comprises the incandescent lamp of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Incandescent lamp 11 Light-emitting tube 12 Sealing part 13 Exhaust pipe remainder 15 Glass pieces 16A, 16B, 16C Metal foil 19 Socket 21 Common internal lead bar 22 First filament internal lead bar 23 Second filament internal lead bar 24 Connecting internal lead rod 25 Connecting member 26A Long axis anchor 26B Short axis anchor 27A Long axis anchor 27B Long axis anchor 30 First filament 33 Filament segment (first segment)
34A Upper part 34B Lower part 40 Second filament 43 Filament segment (second segment)
44A upper part 44B lower part 60 incandescent lamp 61 arc tube 63A common internal lead bar 63B first filament internal lead bar 63C second filament internal lead bar 65A, 65B glass pieces 66A, 66B anchor 69 socket 71 first 1 filament 71A filament segment (first segment)
71B Tobe portion 75 Second filament 75A Filament segment (second segment)
75B Tobi Club

Claims (4)

Inside the arc tube, a first filament composed of a plurality of filament segments arranged in parallel on the same virtual plane, and the same virtual parallel to the virtual plane in which the filament segments constituting the first filament are arranged in parallel In an incandescent lamp in which a second filament composed of a plurality of filament segments arranged in parallel on a plane is opposed to each other, and power is individually supplied to each of the first filament and the second filament .
The first filament has an even number of filament segments and the second filament has an odd number of filament segments;
The filament segments constituting the first filament and the filament segments constituting the second filament are arranged at different positions on the projection plane in the direction parallel to the virtual plane in which these filament segments are arranged in parallel,
Each of the filament segment constituting the first filament and the filament segment constituting the second filament includes the tube axis of the arc tube, and is disposed symmetrically with respect to a plane perpendicular to the virtual plane in which the filament segments are juxtaposed. Incandescent lamp characterized by Each of the first filament and the second filament is on a projection plane in a direction perpendicular to an imaginary plane in which the filament segments constituting the first filament and the filament segments constituting the second filament are arranged in parallel. Two tangents having a contact point at a position facing each other of each of the two filament segments constituting the other filament adjacent to the filament segment passing through the center of one filament segment constituting one filament The incandescent lamp according to claim 1, wherein the incandescent lamp has a configuration with an angle of 30 ° or more . The separation distance between the first filament and the second filament in the direction perpendicular to the virtual plane in which the filament segments constituting the first filament and the filament segments constituting the second filament are arranged in parallel is 0.5 mm. It is the above, The incandescent lamp of Claim 2 characterized by the above-mentioned. The incandescent lamp according to any one of claims 1 to 3, wherein the first filament and the second filament have different rated power consumption values .

Images