JPH10106510A - Incandescent tube lamp for heat source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the calorific value of a central area and both end parts of a filament at the time of continuous lighting and at the time of turning on/off a lamp by delaying the calorie rise time of a high calorific value coil of a light emitting part of an end part in comparison with the calorie rise time of a low calorific value coil of a light emitting part of a central area. SOLUTION: A filament F is formed of two end light emitting part HA formed of a high calorific value coil and plural central area light emitting part HB formed of a low calorific value coil, and adjacent light emitting parts are connected to each other by a non-light emitting part N. At least one of three kinds of factors of coil shape, namely, raw wire diameter of coil wire, coil inner diameter and coil pitch of the high calorific value coil is formed larger than that of the low calorific value coil so that calorie rise time thereof is larger than that of the low calorific value coil. With this structure, at the time of continuous lighting, calorific value of the end light emitting part HA is sufficiently larger than that of the central area light emitting part HB, and at the time of ON/OFF control, calorific value of the end light emitting part HA can be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube-type incandescent lamp for a heat source, which is incorporated, for example, as a heat source in a heating roller device.

[0002]

2. Description of the Related Art For example, a fixing roller such as an electrophotographic copying machine or a printer is provided with a heating roller. FIG. 4 is an explanatory side view showing an example of such a heating roller. In this figure, a heating roller 10 has a tube-shaped incandescent lamp 20 for a heat source disposed inside a sleeve-shaped roller body 11, and a rotation driving gear 12 at one end of the roller body 11.
Is fixed and the other end is supported by the rotation support member 13 so as to be rotatable.

As shown in FIG. 5, a tube-type incandescent lamp 20 for a heat source for such a heating roller has a plurality of light-emitting portions in a tube-type bulb 21 made of glass along the tube axis direction. Filament F in which non-light emitting portions are alternately arranged
Are widely used. 22
Is a metal foil buried in the pinch seals at both ends of the bulb 21, 23 is an external lead rod extending from the metal foil 22, and 25 is a filament supporter.

However, in a heating roller for a fixing device, immediately after the main switch of the device is turned on, the roller surface temperature rises to a usable temperature range within a short period of time, and the warm-up time is short. During the processable period (standby period) after the temperature has risen to the temperature range, it is necessary that the roller surface temperature is stably maintained in the usable temperature range so that the intended heating process is performed at any time. Therefore, as a lighting circuit for operating the tube-type incandescent lamp for a heat source, a continuous lighting function of continuously energizing and lighting the tube-type incandescent lamp during the warm-up period, and a relatively light-emitting circuit during a processable period after the warm-up is completed. A device having an on / off control function of intermittently supplying power for a short time is used. In a practical example, the length of the warm-up period is, for example, 2 minutes,
The on-time (energization duration) in the off-control is, for example, 1
The off time (power stop time) in seconds is, for example, about 3 seconds.

On the other hand, the heating roller during the processable period needs to have a uniform surface temperature in the longitudinal direction. However, at both end portions of the roller body 11, the rotation driving gear 12 and the rotation supporting member 13 are provided. Because the heat is taken away and the heat radiation action is large compared to the central area, simply heating the roller body uniformly in the length direction will significantly reduce the surface temperature of the heating roller at both ends. .

In order to solve such a situation and to make the surface temperature of the heating roller uniform over the entire length, the degree of heating at both end portions of the heating roller is controlled by comparing the degree of heating to the other central region. You just need to increase it. For this reason, tube-type incandescent lamps having a filament that generates heat at both end portions larger than the central region are conventionally used as a heat source.

FIG. 6 is an explanatory view showing the structure of such a filament. The filament F has two end light emitting portions HA arranged at both ends corresponding to both end portions of the heating roller, and nine remaining central region light emitting portions HB corresponding to the central region of the heating roller. However, these light emitting portions are formed as having the same coil form by coiling a single tungsten wire for manufacturing reasons. Here, the “same coil form” means that all three factors of the wire diameter, the coil inner diameter, and the coil pitch of the wire forming the coil are the same. Here, the “coil pitch” is, as shown in FIG. 7, when a lead distance for one turn in a coil made of a wire having a wire diameter a is b (b / a).
Means a factor represented by Then, the end light emitting section H
In order to make A have a larger calorific value, the end light emitting portion HA has a larger coil length than the central region light emitting portion HB.

As a specific example of the conventional dimensions, a filament for a tube-type incandescent lamp having a rated voltage of 120 V and a rated power of 500 W has a non-light-emitting portion N composed of a single line of 7 mm each.
Through the end light emitting portions HA each having a length of 30 mm (2 pieces)
And central area light emitting portions HB (9 pieces) each having a length of 12 mm
Are connected in series, and the coil form is a wire diameter of 0.2
2 mm, the coil inner diameter is 0.7 mm, and the coil pitch is 1.3. According to this filament, each end light emitting section HA has a power density of 2.98 W / mm and a color temperature at the time of lighting of 2420 K, and each of the central area light emitting sections HB has a power density of 1.81 W / mm. The color temperature at that time was 2380K.

FIG. 8 is a curve showing the change over time in the amount of heat generated when a current is applied to each of the coil constituting the end light emitting portion HA and the coil constituting the central region light emitting portion HB of the above-mentioned conventional example. FIG. As is clear from this figure, when the filament coil is continuously energized, the calorific value rises sharply from the time T0 when the energization is started, and thereafter the rate of increase in the calorific value decreases, and the calorific value is saturated after a long time. I will be. The calorific value at this time is referred to as “equilibrium calorific value”.
It is constituted by a coil having a larger calorific value than the central area light emitting section HB.

According to the tubular incandescent lamp having the filament having the above-described configuration, when the lamp is turned on, the heating value of the end light emitting portions HA at both ends of the filament is larger than that of the central region light emitting portion HB. Both end portions of the roller are heated more strongly than the central region, and as a result, the surface temperature of the heating roller becomes more uniform in the length direction.

[0011]

However, in the conventional tube-type incandescent lamp for a heat source, in the continuous lighting during the warming-up period of the heating roller, the degree of heating at both ends is stronger than that in the central region. Although the temperature at both ends of the heating roller is prevented from becoming low, the surface temperature at both ends of the heating roller becomes excessively large during the processable period in which the operation is performed by the on / off control after the warm-up is completed. It was found that the length became non-uniform. It has been found that this is because the influence of the heating by the end light emitting portion HA having a large heat value appears as it is, even if the on-time (continuation time) by the on / off control is short. Was.

FIG. 9 is a characteristic curve diagram showing the heat distribution characteristics of a tube-type incandescent lamp for a heat source having the above-mentioned filament.
In the case of continuous lighting by continuous energization, the lighting is intermittent lighting by on / off control, and the on time is 1 second and the off time is 3
In the case of seconds, the case where the ON time is 0.5 seconds and the OFF time is 3 seconds, and the case where the ON time is 0.2 seconds and the OFF time is 3 seconds are shown. As is clear from this figure, in the conventional tube-type incandescent lamp, even in the operation by the on / off control, the amount of heat generated at both ends is significantly higher than that in the central region, as in the case of continuous lighting. As a result, it is understood that the surface temperature at both ends of the heating roller becomes excessively high. In this figure, the reason why the amount of heat generated at both ends increases as the ON time becomes shorter is as follows.
The ratio of the calorific value of both ends to the calorific value of the central area is
This is because it becomes larger as the on-time becomes shorter.

In recent years, the thickness of the metal sleeve forming the roller body of the heating roller tends to be small. However, in the case of the heating roller using such a roller body, the above-described influence appears. Notable. In addition, the phenomenon that the surface temperature of the heating roller becomes excessive at both ends is caused by fixing only an image forming sheet (usually paper) having a small width to consume heat only in the central portion of the heating roller. It is also promoted by

The present invention has been made to solve the above-described problems. It is an object of the present invention to provide a continuous lighting device in which the amount of heat generated at both ends is sufficiently larger than that in a central region, and the operation by on / off control is performed. An object of the present invention is to provide a tube-type incandescent light bulb for a heat source that can suppress the amount of heat generated at both ends.

[0015]

According to the present invention, there is provided a tube-type incandescent lamp for a heat source, in which a plurality of light-emitting portions and non-light-emitting portions are alternately arranged in a tube-shaped bulb along the tube axis direction. A tube-type incandescent light bulb for a heat source, wherein the end light emitting portions located at both ends of the filament are constituted by a high heating value coil having a large heating value, and a central region light emitting portion other than the end light emitting portion is provided. Are composed of a low heat generation coil having a small heat generation amount, and the high heat generation coil is characterized in that the heat generation rise time is later than that of the low heat generation coil.

In the above description, the high heat generation coil has a configuration in which the wire diameter of the coil wire is larger than the low heat generation coil, a configuration in which the coil inner diameter is larger than the low heat generation coil, or a low coil pitch. At least one of the forms that are larger than the heating value coil is adopted.

According to the tube-type incandescent light bulb for a heat source of the present invention, the end light emitting portions located at both ends of the filament are constituted by high heat generating coils having a large amount of calorific value, and other than the end light emitting portions. The central area light-emitting part is composed of a low calorific value coil with a small equilibrium calorific value, and the high calorific value coil has a slower heat rise time than the low calorific value coil. In addition to being able to heat more strongly, in the operation by the on / off control, the on-time is set so that the energization is stopped in a time region where the actual heat value of the end light emitting portion is smaller than the heat value of the central region light emitting portion. Can be selected, whereby the amount of heat generated at both ends can be suppressed.

[0018]

Embodiments of the present invention will be described below in detail. FIG. 1 is an explanatory diagram showing a configuration of a filament in an example of a tube-type incandescent lamp for a heat source according to the present invention.
This filament F has a total of 11 light-emitting portions, that is, two end light-emitting portions HA and nine central region light-emitting portions HB, and adjacent light-emitting portions are connected by a non-light-emitting portion N. Have been. The end light emitting section HA is constituted by a high calorific value coil having a large balanced calorific value, and the central region light emitting section HB is constituted by a low calorific value coil having a small balanced calorific value. The coil is formed in a coil configuration in which the calorific value rise time is later than that of the low calorific value coil.

In the present invention, the term “heat rise time” for a coil means that when the equilibrium heat generation of the coil is set to 100% in the curve showing the change over time in the heat generation when the coil is energized, energization is started. The time from when the heat value reaches 80%, for example, is referred to as "80% rise time" in this specification.

In the present invention, the low heat generation coil constituting the central area light emitting portion HB has an 80% rise time of, for example, 0.5 to 2.0 seconds, preferably 1.0 to 1.0.
A coil having a high heating value of 80 seconds is used, for example, 2.0 to 7.0 seconds, and preferably 3.0 to 5.0 seconds. Is used. The high heating value coil requires that the 80% rise time be slower or longer than the low heating value coil, but the degree of the 80% rise time difference is, for example, 0.5 to 8.0 seconds. Preferably 1.0 to
5.0 seconds.

The characteristics of the high heating value coil and the low heating value coil as described above can be realized by changing the coil form. Here, the “coil form” is defined by three factors: the wire diameter (a in FIG. 7), the coil inner diameter (r in FIG. 7), and the coil pitch (b / a in FIG. 7) of the wire forming the coil. Is defined,
The high heating value coil needs to be formed to have at least one factor larger than the low heating value coil. By selecting the length of the coil, a coil having a required equilibrium heat generation can be obtained.

Specifically, it is preferable that the high heat generation coil has any one of the following coil forms (1) to (7) for convenience of filament production. (1) The wire diameter of the coil wire is the same as the low calorific value coil,
Coil inner diameter is the same as low heat value coil, coil pitch is larger than low heat value coil. (2) The wire diameter of the coil wire is the same as that of the low calorific value coil,
Coil inner diameter is larger than low heat value coil, and coil pitch is the same as low heat value coil. (3) The wire diameter of the coil wire is larger than the low heating value coil, the inner diameter of the coil is the same as the low heating value coil, and the coil pitch is the same as the low heating value coil. (4) The wire diameter of the coil wire is the same as that of the low calorific value coil,
Coil inner diameter is larger than low heating value coil, coil pitch is larger than low heating value coil. (5) The wire diameter of the coil wire is larger than the low heating value coil, the coil inner diameter is the same as the low heating value coil, and the coil pitch is larger than the low heating value coil. (6) The wire diameter of the coil wire is larger than the low heating value coil, the coil inner diameter is larger than the low heating value coil, and the coil pitch is the same as the low heating value coil. (7) The wire diameter of the coil wire is larger than the low heating value coil, the coil inner diameter is larger than the low heating value coil, and the coil pitch is larger than the low heating value coil.

The high heating value coil only needs to have a heating time that is later than that of the low heating value coil. Therefore, if this condition is satisfied, the high heating value coil is determined by any one of the factors of the coil form. May be smaller than the low heating value coil. However, such filaments may require high manufacturing costs.

According to the tube-type incandescent lamp for a heat source of the present invention, as is apparent from the description of the embodiment described later, the end light emitting portion H
The high calorific value coil of A has a larger calorific value than the low calorific value coil of the central area light emitting portion HB, but has a slower calorific value rise time than the low calorific value coil. The amount of heat generated by the end light emitting section HA can be increased by setting the length of the ON time to a short time equal to or less than a certain length. Is the central area light emitting section H
B can be in a state smaller than the calorific value of B. In such on / off control, when the on-time starts, both the edge light-emitting portion HA and the central region light-emitting portion HB start to generate heat at the same time. This is because the on-time ends before the heat generation amount of the light emitting unit HA exceeds the heat generation amount of the central region light emitting unit HB composed of the low heat generation amount coil having a fast heat rise time.

In the heating roller device incorporating such a tube type incandescent lamp for a heat source, during the warming-up period, both ends are heated more strongly than the central region by continuous lighting, and the processing after the warming-up is completed. During the period, the degree of heating at both ends is suppressed by the operation of the on / off control, so that the surface temperature of the heating roller is stably maintained in a highly uniform state in the length direction. As a result, a heat treatment such as a required fixing process can be performed extremely well.

[0026]

EXAMPLE A filament for a tubular incandescent lamp having a rated voltage of 120 V and a rated power of 500 W was produced using a tungsten wire according to the structure shown in FIG. This filament has a series of end light emitting portions HA (two) each having a length of 30 mm and a central region light emitting portion HB (nine) each having a length of 12 mm via a non-light emitting portion N of a single wire portion of 7 mm each. The end light emitting portion HA has a coil shape of a wire diameter of 0.26 mm, a coil inner diameter of 0.9 mm, a coil pitch of 1.3, and a central region light emitting portion HB.
Has a wire element diameter of 0.22 mm, a coil inner diameter of 0.7 mm, and a coil pitch of 1.3. In this filament, the coil form of the high heating value coil has the same coil pitch as that of the low heating value coil,
Both the wire diameter and the coil inner diameter of the coil wire are large.

When a tube-type incandescent lamp having a filament having such a structure is turned on, each end light emitting portion HA has a power density of 2.98 W / mm and a color temperature of 2250 K when turned on.
And each of the central region light emitting portions HB has a power density of 1.8.
The color temperature at the time of lighting at 1 W / mm was 2380K.

It should be noted that there is a linear relationship between the color temperature of the coil of each light emitting unit and the heat rise time of the coil during lighting, in which the shorter the heat rise time, the higher the color temperature. Therefore, in the filament of the tube-type incandescent lamp of the present invention, since the high heat generation coil of the end light emitting portion HA has a slow heat rise time, the color temperature is lower than that of the low heat generation coil.

The filament of FIG. 1 has the same coil configuration of the central region light emitting portion HB as compared to the conventional filament of FIG. 6, but has a different coil configuration of the end portion light emitting portion HA. The light emitting section HA has a lower color temperature than the conventional one even though the power density is the same as the conventional one.
In the conventional filament, the coil of the end light emitting section HA has an 80% rise time of 1.15 seconds.
The coil of the central area light emitting section HB has an 80% rise time of 1.78 seconds. Table 1 shows a comparison between the two.

[0030]

[Table 1]

FIG. 2 is a graph showing the change over time in the amount of heat generated when current is applied to each of the high heating value coil of the end light emitting portion HA and the low heating value coil of the central region light emitting portion HB according to the above embodiment. FIG. As is clear from FIG. 2, the high heating value coil has a larger calorific value than the low heating value coil, but has a slower heat rise time. In the figure, T0 is the point of time when the energization starts, TL is the point of time when the 80% rise time of the low heat generation coil has elapsed, and TH is the point of time when the 80% rise time of the high heat generation coil has elapsed. Specifically, the 80% rise time of the high heat value coil is 4.25 seconds, and the 80% rise time of the low heat value coil is 1.24 seconds. And, as shown in this figure, both curves have an intersection point P at a time point Tx that exceeds the 80% rise time of the low heating value coil, and at this time point Tx, the heating value of the high heating value coil And the calorific value of the low calorific value coil are equal. Then, the time t from the time T0 when the energization is started to the equal heat generation time Tx is referred to as "preceding heating time of the low heat generation coil".

According to the tube-type incandescent light bulb for a heat source having the above-described configuration, in continuous lighting, continuous lighting is performed continuously for a period of time exceeding the time point Tx, and both ends of the light emitting portion HA are heated by the high heating value coil. In the heating roller device, the heating amount of both ends is sufficiently larger than that of the central region, and sufficient warming-up can be performed in a short time without lowering the temperature of both ends in the heating roller device. .

After the warming-up is completed, in the processable period after the surface temperature of the heating roller reaches the usable temperature range, the tube-type incandescent lamp is operated by the on / off control of the lighting circuit to turn on and off the lamp. The time is alternately repeated, but the length of the ON time in this ON / OFF control is set to a time shorter than the preceding heating time t of the low heat value coil.

As a result, the tube-type incandescent lamp generates heat during the ON time, but the amount of heat generation is small in the high heat generation coil and high in the low heat generation coil. This is clear from FIG. That is, in the example of FIG. 2, if the set ON time is set to a time equal to, for example, the 80% rise time of the low heat generation coil, the heat generation amount of the high heat generation coil at this time (TL) is Heat generation is stopped because it is about half of the calorific value and then the off time. By continuing such ON / OFF control, the degree of heating at both ends of the heating roller is suppressed, so that the temperature at both ends is prevented from becoming excessively high, and the surface of the heating roller is prevented. The temperature is stably maintained in a state where the temperature becomes uniform in the length direction in the usable temperature range.

FIG. 3 is a characteristic curve diagram showing heat distribution characteristics of the tube-type incandescent lamp according to the embodiment of FIG. 1. In the case of continuous lighting by continuous energization, intermittent lighting by on / off control. A case where the ON time is 2 seconds and the OFF time is 3 seconds, a case where the ON time is 1 second and the OFF time is 3 seconds, and a case where the ON time is 0.5 seconds and the OFF time is 3 seconds are shown. This curve is measured by scanning the thermal sensor in the length direction of the bulb at a position 15 mm away from the central axis (tube axis of the bulb) of the tubular incandescent lamp. This is a relative scale with the calorific value at the central position of the central region being 100%, and the horizontal axis represents the distance with the central point in the length direction of the valve being 0.

As is apparent from this figure, for example, when the on-time is 1 second and the off-time is 3 seconds, and when the on-time is 0.5 second and the off-time is 3 seconds, the edge light emitting portion HA is surely provided. Can be suppressed. As a result, in the heating roller device incorporating the tube-type incandescent lamp, even during the processable period, the surface temperature of the heating roller has a uniform distribution in the length direction, and a good heat treatment can be performed. It will be.

The structure of the filament of the tubular incandescent lamp according to another embodiment of the present invention will be described below. This filament is
It is disposed in a tube-type incandescent lamp having a rated voltage of 120 V and a rated power of 500 W, and each of the end light emitting portions HA having a length of 40 mm via a non-light emitting portion N of a single wire portion of 7 mm.
(2 pieces) and a central area light emitting portion HB each having a length of 12 mm
(9 pieces) are connected in series, and the coil form of the end light emitting portion HA is such that the element wire diameter of the wire is 0.22 mm, the coil inner diameter is 0.7 mm, the coil pitch is 1.8, and the central area light emission. The coil form of the portion HB is such that the wire diameter of the wire is 0.2.
2 mm, the coil inner diameter is 0.7 mm, and the coil pitch is 1.3.

The filament of the high heat generation coil has the same wire diameter and the inside diameter of the coil wire as the low heat generation coil, and has a large coil pitch. When the tube-type incandescent lamp having the filament was turned on, each end light emitting portion HA had a power density of 2.
The color temperature at the time of lighting at 98 W / mm is 2250 K, and the power density of each of the central area light emitting units HB is 1.81 W / mm.
And the color temperature at the time of lighting was 2380K.

Although the tube-type incandescent lamp for a heat source of the present invention has been described above, various changes can be made in the present invention. For example, the number and characteristics of the central region light emitting portions HB are not particularly limited, and can be changed according to the purpose.

[0040]

According to the tubular incandescent light bulb for a heat source of the present invention,
In continuous lighting, both ends can be heated more strongly than in the central area, and in operation by on / off control, electricity is supplied in a time area where the actual heat value of the end light emitting section is smaller than the heat value of the central area light emitting section. The length of the on-time can be selected so as to stop the heat generation, whereby the heat generation amount at both ends can be suppressed.

As a result, according to the heating roller device in which the tube-type incandescent lamp for heat source of the present invention is incorporated, the tube-type incandescent lamp for heat source is operated as described above, so that the continuous energization is performed during the warm-up period. Both end portions are heated more strongly than the central region, and the degree of heating of both end portions is suppressed by on / off control during the processable period, so that the surface temperature of the heating roller is set longer in the usable temperature range. Since it is possible to stably maintain a state of high uniformity in the vertical direction, it is possible to very well execute a heating process such as a required fixing process.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a filament in an example of a tube-type incandescent lamp for a heat source according to the present invention.

FIG. 2 is a curve diagram showing a temporal change of a heat generation amount when current is supplied to coils constituting an end light emitting portion and a central region light emitting portion of the filament in the example of FIG.

FIG. 3 is a characteristic curve diagram showing heat distribution characteristics of the tubular incandescent lamp according to the example of FIG. 1;

FIG. 4 is an explanatory side view illustrating an example of a heating roller.

FIG. 5 is an explanatory diagram illustrating a configuration of an example of a tube-type incandescent lamp for a heat source.

FIG. 6 is an explanatory diagram showing a configuration of a filament of a conventional tube-type incandescent lamp for a heat source.

FIG. 7 is an explanatory diagram of a coil pitch.

FIG. 8 is a curve diagram showing a change over time of a heat generation amount when current is supplied to coils constituting an end light emitting portion and a central region light emitting portion of the filament of FIG. 6;

FIG. 9 is a characteristic curve diagram showing heat distribution characteristics of the conventional tubular incandescent lamp shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heating roller 11 Roller body 12 Rotation drive gear 13 Rotation support member 20 Tube type incandescent lamp for heat source 21 Tube type bulb F Filament 22 Metal foil 23 External lead rod 25 Filament supporter HA Edge light emitting part HB Central area light emitting part

Claims (4)

[Claims] 1. A tube type incandescent lamp for a heat source, comprising: a filament in which a plurality of light-emitting portions and non-light-emitting portions are alternately arranged along a tube axis direction in a tube-type bulb. The end light emitting portions located at both ends are composed of high calorific value coils having a large equilibrium calorific value,
The central region light emitting portion other than the end portion light emitting portion is constituted by a low calorific value coil having a small equilibrium calorific value, and the high calorific value coil is characterized in that the calorific value rise time is slower than the low calorific value coil. Tube type incandescent bulb for heat source. 2. The tube-type incandescent lamp for a heat source according to claim 1, wherein the high heating value coil has a wire diameter of a coil wire larger than that of the low heating value coil. 3. The high heating value coil has a coil inner diameter larger than the low heating value coil.
The tubular incandescent light bulb for a heat source according to 1. 4. The tubular incandescent light bulb for a heat source according to claim 1, wherein the high heat generation coil has a coil pitch larger than that of the low heat generation coil.