JP2001221608A - Rotational position detecting device and rotational position determining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotational position deciding device which can decide the rotational position of a mercury flag 7 with high accuracy, in the process of manufacturing a fluorescent lamp. SOLUTION: In a fluorescent tube 2 driven rotationally by means of a motor 18, a mercury flat 7 is arranged eccentrically. In order to position the flag 7 to a target rotation position A, a pair of sensors 21 and 22 which produce analog outputs correspondingly to the position of the flag 7 is arranged at positions B and C, which are shifted from the position A by prescribed angles in the opposite directions. The analog outputs from the sensors 21 and 22 are inputted to a comparator 23, which makes a reverse output at the time the magnitude relation between the analog outputs is switched. A controller 24 discriminates the target rotational position A, based on the reverse output and instantaneously stops the rotational driving of the tube 3 by means of the motor 18. Consequently, the mercury flag 7 can be positioned to the target rotational position A with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational position detecting device and a rotational positioning device. For example, the present invention relates to a rotational position detecting device for determining the rotational detection position of a mercury flag eccentrically arranged inside a fluorescent lamp, and its detection. The present invention belongs to the technical field including a rotary positioning device that rotationally positions a fluorescent lamp so that a mercury flag is arranged at a specific target rotation position according to a result.

[0002]

2. Description of the Related Art As is clear from the principle of operation of a fluorescent lamp, it is necessary to fill the inside with mercury gas. Further, the inside of the fluorescent lamp is almost in a vacuum state. In the conventional fluorescent lamp manufacturing process, liquid mercury is charged inside and the inside of the fluorescent lamp is evacuated,
The mercury gas was generated by the depressurizing action.

However, in the conventional method of manufacturing a fluorescent lamp, it is necessary to put mercury into a fluorescent lamp in a liquid state, and it is difficult to input a fixed amount of mercury at a time. Is very difficult.

Therefore, it has been considered to fix the mercury flag to a stem mount having a filament or the like fixed to the end of the fluorescent tube so as to face the inside of the fluorescent tube. It is conceivable that the mercury flag is constituted by a metal plate containing mercury.

In this case, with the mercury flag facing the inside of the fluorescent tube, the mercury flag is subjected to high-frequency heating by a high-frequency induction heating device arranged outside, so that mercury is deposited from the mercury flag, and the mercury is placed inside the fluorescent tube. The steam will fill up.

[0006]

When a fluorescent lamp is manufactured using the above-mentioned mercury flag, if the heating efficiency of the high-frequency induction heating device can be maximized, the efficiency of mercury deposition from the mercury flag can be improved. The production efficiency of fluorescent lamps can be increased. Further, if the degree of heating by the high-frequency induction heating device is constant every time, the performance between the fluorescent lamps becomes uniform, which is preferable in keeping the quality of the fluorescent lamps constant. To derive these advantages, it is conceivable to accurately direct the plate surface of the mercury flag to the heating side of the high-frequency induction heating device.

However, since the fluorescent material is coated on the inner peripheral side of the fluorescent tube as is well known, it is almost impossible to visually detect the position of the mercury flag disposed inside the fluorescent tube from the outside. is there.

Then, the fluorescent lamp is rotated around its axis,
That is, a rotation driving mechanism for rotating, a single eddy current displacement sensor arranged corresponding to a target rotation position of the mercury flag, and a control device for controlling the rotation driving mechanism according to an output result from the sensor. It is conceivable to use a rotary positioning device provided.

That is, as shown in FIG. 8, when the target rotation position of the mercury flag 42 in the fluorescent tube 41 is set to the position directly above, the sensor 43 is set at a position corresponding to the target rotation position of the mercury flag 42, that is, The fluorescent tube 41 is rotated (rotated) by the rotation driving mechanism 44 in a state where the fluorescent tube 41 is disposed directly above the fluorescent tube 41. Then, the rotation angle position at which the peak value of the analog output voltage from the sensor 43 due to the approach of the mercury flag 42 at the first rotation of the fluorescent tube 41 is detected. Further, by continuing the rotation by the rotation drive mechanism 44, the mercury flag 42 can be stopped at the target rotation position by controlling the position of the mercury flag 42 at the detected rotation angle position at the second rotation.

However, in such a rotary positioning device, the amount of change in the analog output voltage from the sensor 43 near the peak value from the sensor 43 is very small, as shown in FIG. In addition, in general, an inexpensive eddy current type displacement sensor has a characteristic in which the vicinity of the peak value is depressed as shown by a dotted line in FIG.

Therefore, in order to improve the positioning accuracy, it is necessary to increase the accuracy of the sensor 43 and the signal processing circuit on the control device side. Even if the accuracy of the signal processing circuit is improved, the characteristics of the analog signal of the sensor 43 near the peak value are unstable, so that the highly accurate position detection and positioning are not necessarily expected. It is not possible. Specifically, as shown in FIG. 9, a difference occurs between the rotation position that is the expected peak value obtained by the signal processing and the actual target rotation position.

In addition, the mercury flag 42 has already exceeded the target rotational position when the rotational position at which the expected peak value is found is known, due to the fact that the amount of change near the peak value is minute or unstable. I have. Therefore, as described above, one rotation is required at maximum for detecting the positioning angle of the fluorescent tube 41 at the target rotation position, and another rotation is required for positioning the fluorescent tube 41 at the detected angular position. Since a maximum of two rotations are required for positioning one fluorescent tube 41, there is a problem that it is difficult to achieve high-speed positioning.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and one of its main objects is to provide a rotational position detecting device and a rotational positioning device capable of achieving high precision in rotational position detection and rotational positioning. Is to get

Another object of the present invention is to provide a rotary positioning device capable of increasing the speed up to positioning.

Another object is to achieve each of the above-mentioned objects with a simple structure, and particularly to improve the positioning accuracy and positioning speed of the mercury flag when the mercury flag is used for manufacturing a fluorescent tube. Increasing the production efficiency of the fluorescent lamp and keeping the quality of the fluorescent lamp constant can be cited.

[0016]

Means for Solving the Problems and Effects There will be described below characteristic means for achieving the above object. Also,
For each means, characteristic actions and effects will be described as necessary.

Means 1. What is claimed is: 1. A rotation position detecting device for detecting that an object to be rotationally driven is arranged at a predetermined target detection position, wherein the device is located at a predetermined distance from a rotation center of the object to be detected, and the target detection is performed. A first detection unit which is arranged at a position shifted by a predetermined angle from the position to one side and outputs an output according to a distance from the detected object, and a position separated by a predetermined distance from a rotation center of the detected object, And a second sensor which is arranged at a position deviated from the target detection position by the same angle as the predetermined angle from the target detection position and outputs an output according to the distance from the detection object with the same characteristics as the first detection means.
Detecting means, comparing means for comparing the magnitude relationship between the two outputs from the two detecting means, and when the magnitude relation between the two outputs changes in the comparison result of the comparing means, the object to be detected is arranged at the target detection position. And a determining means for determining that the rotation has been performed.

According to the above means 1, when the object to be detected is driven to rotate, an output is made from the first detecting means and the second detecting means according to the position. Such an output is preferably an analog output. The magnitude relationship between the two outputs from both the detecting means is compared by the comparing means. When a comparison result indicating that the magnitude relationship has changed is obtained from the comparison means, the discrimination means discriminates at that time that the object to be detected has been arranged at the target detection position.

Here, the first detecting means and the second detecting means are
A position separated by a predetermined distance from the rotation center of the detected object,
Further, since they are arranged at positions shifted by equal angles in opposite directions from the target detection position, the point of coincidence of the two outputs, that is, the point of change in the magnitude relationship between the two outputs becomes the target detection position. Therefore, the target detection position can be reliably and easily detected by the determination means based on the comparison output of the comparison means without performing complicated arithmetic processing. Moreover, since the comparing means compares the relative relationship between the two outputs from the two detecting means, the distance from the rotation center of the object to be detected becomes unstable and the absolute output value changes. However, the target detection position can be accurately known without any problem. As described above, according to the means 1, the target detection position can be detected with high accuracy by a simple configuration.

Means 2. A motor for rotationally driving the object to be detected, control means for driving and controlling the motor, and a rotational position detecting device for detecting that the object to be rotationally driven is arranged at a predetermined target detection position. A rotation positioning device, wherein the rotation position detection device is located at a position separated by a predetermined distance from the rotation center of the object to be detected, and is disposed at a position shifted by a predetermined angle from the target detection position to one side, 1st output that outputs according to the distance from the detected object
A detection unit, which is located at a position separated by a predetermined distance from the rotation center of the object to be detected and is shifted from the target detection position to the other by the same angle as the predetermined angle, and is the same as the first detection unit. A second detecting means for outputting an output according to the distance from the object to be detected with a characteristic, a comparing means for comparing the magnitude relationship between the two outputs from the two detecting means, and the two outputs in a comparison result of the comparing means. Discriminating means for discriminating that the object to be detected has been arranged at the target detection position when the magnitude relationship of the object has changed, and wherein the control means determines that the object to be detected has been arranged at the target detection position by the discrimination means. And a stop control of the motor for stopping the object to be detected at a target rotation position predetermined in relation to a target detection position in response to the determination.

According to the means 2, when the motor is driven to rotate by the control signal from the control means, the object to be detected is driven to rotate accordingly. Output is performed from the first detection means and the second detection means according to the rotational position of the detected object. Such an output is preferably an analog output.
The magnitude relationship between the two outputs from both the detecting means is compared by the comparing means. When a comparison result indicating that the magnitude relationship has changed is obtained from the comparison means, the discrimination means discriminates at that time that the object to be detected has been arranged at the target detection position. The control means controls the motor to stop in order to stop the detected object at the target rotation position when the determining means determines that the detected object is located at the target detection position.

Here, the first detecting means and the second detecting means include:
A position separated by a predetermined distance from the rotation center of the detected object,
Further, since they are arranged at positions shifted by equal angles in opposite directions from the target detection position, the point of coincidence of the two outputs, that is, the point of change in the magnitude relationship between the two outputs becomes the target detection position. Therefore, the target detection position can be reliably and easily detected by the determination means based on the comparison output of the comparison means without performing complicated arithmetic processing. Moreover, since the comparing means compares the relative relationship between the two outputs from the two detecting means, the distance from the rotation center of the object to be detected becomes unstable and the absolute output value changes. However, the target detection position can be accurately known without any problem. Further, the object to be detected can be stopped at the target rotation position based on the target detection position accurately detected as described above. The target detection position and the target rotation position may be matched or different, but it is necessary to set a relationship between the two positions in advance.
As described above, according to the means 2, it is possible to accurately detect the target detection position with a simple configuration, and to position the object to be detected at the target rotational position with high accuracy and high speed.

Means 3. The control means determines a rotation direction of the detection object based on a comparison result by the comparison means before the start of rotation of the detection object, and controls driving of the motor so that the detection object rotates in the rotation direction. 3. The rotation positioning device according to claim 2, wherein

According to the above means 3, if the outputs from both the detecting means have a characteristic that the output becomes larger as the object to be detected approaches, the output from the first detecting means is smaller than the output from the second detecting means. If it is larger, it can be seen that the current position of the detected object before rotation is closer to the first detector from the target detected position. By utilizing this characteristic, it is possible to determine the rotation direction in which the target detection position can be reached quickly, that is, the shortest path. Therefore, the object to be detected can reach the target detection position as soon as possible, and the speeding up of the positioning can be further promoted.

Means 4. The predetermined angles are set so that the output from the first detection unit decreases and the output from the second detection unit increases near the position where the detection target is located at the target detection position. An apparatus according to any one of the above means 1 to 3, characterized in that:

According to the means 4, the detecting means such as an eddy current type displacement sensor which performs analog output generally has an unstable output near the peak value, while the rising and falling parts, which are the output parts on both sides thereof, The output is relatively stable. Therefore, by setting the positions of both detecting means so that the intersection of the rising part of one detecting means and the descending part of the other detecting means becomes the target detection position, highly accurate detection becomes possible.

Means 5. What is claimed is: 1. A rotation position detecting device for detecting that an object to be rotationally driven is arranged at a predetermined target detection position, wherein the device is located at a predetermined distance from a rotation center of the object to be detected, and the target detection is performed. A detecting unit that is arranged at a position shifted by a predetermined angle from the position to one side and outputs an output according to a distance from the detected object, and a position separated by a predetermined distance from a rotation center of the detected object, and It is arranged at a position shifted by the same angle as the predetermined angle from the target detection position to the other, so that an output corresponding to the distance from the object to be detected is obtained with the same characteristics as the detection means,
Processing means for processing the output of the detection means, comparison means for comparing the magnitude relationship between the two outputs from the detection means and the processing means, and when the magnitude relationship between the two outputs changes in the comparison result of the comparison means. A rotation position detection device comprising: a determination unit configured to determine that the detection target is located at the target detection position.

According to the means 5, when the object to be detected is driven to rotate, an output is made from the detecting means in accordance with the position. Further, the output of the detecting means is processed by the processing means and a predetermined output is performed. Then, the magnitude relation between the outputs from the detecting means and the processing means is compared by the comparing means. When a comparison result indicating that the magnitude relationship has changed is obtained from the comparison means, the discrimination means discriminates at that time that the object to be detected has been arranged at the target detection position.

Here, assuming that the output from the processing means is the output from the virtual detecting means, the actually provided detecting means and the virtual detecting means are positioned at a predetermined distance from the rotation center of the object. And it can be considered that they are arranged at positions shifted by equal angles in opposite directions from the target detection position, so that the point of coincidence between the two outputs, that is, the point of change in the magnitude relationship between the two outputs is the target detection position. Becomes Therefore, the target detection position can be reliably and easily detected by the determination means based on the comparison output of the comparison means without performing complicated arithmetic processing. Moreover, since the comparison means compares the relative relationship between the outputs from the detection means and the processing means serving as the virtual detection means, the distance from the rotation center of the object to be detected becomes unstable and absolutely. Even if there is a change in the output value, the target detection position can be accurately known without any problem. As described above, according to the means 5, the target detection position can be detected with high accuracy by a simple configuration. Moreover,
An accurate target detection position can be determined without being influenced by a slight shift in the characteristics of the two detection means or a slight shift in arrangement as in the case of actually disposing a pair of detection means as in the above means 1. can do. Of course, there is also an advantage that only one detecting means needs to be used.

Means 6. A motor for rotationally driving the object to be detected, control means for driving and controlling the motor, and a rotational position detecting device for detecting that the object to be rotationally driven is arranged at a predetermined target detection position. A rotation positioning device, wherein the rotation position detection device is located at a position separated by a predetermined distance from the rotation center of the object to be detected, and is disposed at a position shifted by a predetermined angle from the target detection position to one side, Detecting means for performing output in accordance with the distance from the detected object, and a position which is separated by a predetermined distance from the rotation center of the detected object, and is shifted from the target detection position to the other by the same angle as the predetermined angle. Processing means for processing the output of the detecting means so that an output corresponding to the distance from the object to be detected is obtained at the same position as the detecting means and having the same characteristics as the detecting means; and Comparing means for comparing the magnitude relationship between the two outputs, and discriminating means for determining that the object to be detected is located at the target detection position when the magnitude relationship between the two outputs changes in the comparison result of the comparing means. And a control unit configured to, upon receiving a determination that the detection target is disposed at the target detection position by the determination unit, set the detection target in a target rotation predetermined in relation to the target detection position. A rotation positioning apparatus, wherein the motor is controlled to stop at a position.

According to the means 6, when the motor is driven to rotate by the control signal from the control means, the object to be detected is driven to rotate accordingly. Output is performed from the detecting means according to the rotational position of the detected object. Such an output is preferably an analog output. Further, the output of the detecting means is processed by the processing means and a predetermined output is performed.
Then, the magnitude relation between the outputs from the detecting means and the processing means is compared by the comparing means. When a comparison result indicating that the magnitude relationship has changed is obtained from the comparison means, the discrimination means discriminates at that time that the object to be detected has been arranged at the target detection position. The control means controls the motor to stop in order to stop the detected object at the target rotation position when the determining means determines that the detected object is located at the target detection position.

Here, assuming that the output from the processing means is the output from the virtual detecting means, the actually provided detecting means and the virtual detecting means are positioned at a predetermined distance from the rotation center of the object. And it can be considered that they are arranged at positions shifted by equal angles in opposite directions from the target detection position, so that the point of coincidence between the two outputs, that is, the point of change in the magnitude relationship between the two outputs is the target detection position. Becomes Therefore, the target detection position can be reliably and easily detected by the determination means based on the comparison output of the comparison means without performing complicated arithmetic processing. Moreover, since the comparison means compares the relative relationship between the outputs from the detection means and the processing means serving as the virtual detection means, the distance from the rotation center of the object to be detected becomes unstable and absolutely. Even if there is a change in the output value, the target detection position can be accurately known without any problem. As described above, according to the means 5, the target detection position can be detected with high accuracy by a simple configuration. Moreover,
An accurate target detection position can be determined without being affected by a slight shift in the characteristics of the two detecting means or a slight shift in arrangement as in the case of actually disposing a pair of detecting means as in the above means 2. can do. Of course, there is also an advantage that only one detecting means needs to be used. Further, the object to be detected can be stopped at the target rotation position based on the target detection position accurately detected as described above. The target detection position and the target rotation position may be the same or different,
It is necessary to set the relationship between the two positions in advance. As described above, according to the means 6, the target detection position can be detected with high accuracy with a simple configuration, and the object to be detected can be positioned with high accuracy and high speed at the target rotation position.

Means 7 The control means is for causing the motor to rotate at a constant speed by rotating the motor at a constant speed, and the processing means is configured such that the delay time from the output of the detection means scheduled from the constant rotation of the detected object is 7. The rotation positioning device according to the above-mentioned means 6, which is constituted by a delay means for performing the same output after elapse.

According to the means 7, the output from the processing means, which is the output from the virtual detection means, can be easily generated by the delay means. The delay means is configured by a delay line or the like in the case of analog output processing,
In the case of digital output processing, a shift register or the like is used.

Means 8. 8. The rotation positioning device according to claim 6, wherein the control means drives and controls the motor so as to rotate in one direction from the detection means side to a target detection position.

According to the above means 8, since the processing means as the output of the virtual detecting means uses the output from the actual detecting means, by determining the rotation direction of the motor, For example, the processing by the processing means such as the delay processing can be uniquely determined, and the processing by the processing means can be simplified.

Means 9 The output from the detection unit and the output from the processing unit are such that the output from the detection unit decreases and the output from the processing unit increases near the position where the detected object is located at the target detection position, or The apparatus according to any one of claims 5 to 8, wherein the predetermined angle is set so that the output from the detection means increases and the output from the processing means decreases.

According to the means 9, the detecting means such as an eddy current type displacement sensor which performs analog output generally has an unstable output near the peak value, while the rising and falling parts which are the output parts on both sides are provided. The output is relatively stable. Therefore, by setting the position of the detection means so that the intersection of the rising part and the falling part of the output from the detection means and the processing means becomes the target detection position, high-precision detection becomes possible.

Means 10. The apparatus according to any one of the above means 1 to 9, wherein when the predetermined angle is α degrees, α is set within a range of 3 to 60.

According to the means 10, the detecting means such as the eddy current type displacement sensor which performs analog output has an output change corresponding to the position change of the object to be detected most in the range of 3 to 60 degrees from the target detection position. Large and stable. Therefore,
By providing the detection means in this range, it is possible to determine the target detection position with high accuracy.

Means 11. 7. The rotation positioning device according to the above means 2 or 6, wherein the target rotation position of the object to be detected is matched with the target detection position.

According to the means 11, since the time when the target detection position is determined is the target rotational position, the control means may stop the motor immediately when the target detection position is determined by the determination means. It will be. This not only simplifies the control by the control means, but also completes the flow from the determination of the target detection position to the stop to the target rotation position in an instant, further speeding up the rotation positioning. can do.

Means 12. The object to be detected is a mercury flag eccentrically arranged inside a fluorescent tube of a fluorescent lamp, and the rotation detecting position of the mercury flag is determined by rotating the fluorescent tube around its longitudinal center line as a rotation center axis. 12. The apparatus according to any one of the above means 1 to 11, wherein

According to the means 12, the mercury flag can be stopped at the target rotation position. Therefore, in the step of filling the fluorescent lamp with mercury gas by heating the mercury flag, the mercury flag is most likely to be stopped. In addition to being able to be placed in a place with good heating efficiency, the mercury gas generation amount can be kept constant by eliminating the variation in arrangement of the mercury flags between the fluorescent lamps. As a result, the production efficiency of the fluorescent lamps can be improved. Variation between fluorescent lamps can be eliminated.

Means 13. The means (1), wherein the mercury flag is cantilevered via a linear member to a stem mount attached to an end of the fluorescent tube.
3. The apparatus according to 2.

According to the means 13, since the mercury flag is cantilevered via a linear member such as a wire, the distance from the center of the fluorescent tube is very unstable. According to the rotation position detection device and the rotation positioning device, the target detection position of the mercury flag can be reliably detected and stopped at the target rotation position.

Means 14. 14. The apparatus according to claim 12, wherein the detecting means is arranged at a small distance outside the outer peripheral surface of the fluorescent tube.

In the above-mentioned means 14, it is particularly preferable that the detecting means is within 3 mm from the outer peripheral surface of the fluorescent tube. By installing the detecting means in this manner, it is possible to cause a sufficient change in output according to the displacement of the mercury flag,
The mercury flag can be detected and positioned with high accuracy.

Means 15. The target detection position and the target rotation position are set to be shifted from each other by a predetermined angle, and after the target detection position is determined by the determination means, the motor is controlled so as to stop the object at the target rotation position by the control means. The rotation positioning device according to the means 2 or 6, wherein:

According to the above-mentioned means 15, since the rotation of the object to be detected can be permitted by a predetermined angle without immediately stopping the object after the target detection position is determined, the target can be rotated until the object is stopped. There is no possibility of exceeding the rotation position. Note that the predetermined angle is preferably, for example, 30 to 60 degrees, and by providing a sufficient margin before the stop of the object to be detected, even if the object to be detected is rotated at high speed, the target rotational position can be accurately determined. Can be stopped. However, when the target detection position and the target rotation position are set so as to be shifted from each other, the rotation direction of the detection target needs to be limited to one direction.

Means 16. After fixing the stem mount at the end of the fluorescent tube and evacuating the inside, the mercury flag attached to the stem mount and facing the inside of the fluorescent tube is heated and filled with mercury gas to fill the fluorescent tube. A fluorescent lamp manufacturing apparatus for manufacturing a lamp, wherein the mercury flag is arranged at a position where the heating efficiency of the mercury flag during the heat treatment is highest.
A fluorescent lamp manufacturing apparatus using the rotation detecting device or the rotation positioning device according to any one of the means 11 to 15.

According to the means 16, the heat treatment can be performed in a state where the mercury flag is arranged at a position where the heating efficiency of the mercury flag is the highest. The position where the heating efficiency is the highest is a position that accurately faces the heating plate. As a result, the fluorescent lamp can be manufactured at high speed, with high accuracy, and as a result, at low cost.

[0053]

[First Embodiment] A first embodiment will be described with reference to FIGS. 1 to 3 and FIG.
In this embodiment, a case will be described in which the fluorescent lamp is rotationally positioned such that the mercury flag present eccentrically in the fluorescent lamp is arranged at a specific target rotation position.

First, the configuration of the fluorescent lamp to be inspected will be described with reference to FIGS. 7 (a) to 7 (c). The fluorescent lamp 1 includes a hollow cylindrical fluorescent tube 2 as a rotating body and a stem mount 3. The fluorescent tube 2 is coated with a fluorescent substance on the inner peripheral side, so that the inside of the fluorescent tube 2 cannot be visually recognized from the outside. The stem mount 3 is fixed to an end of the fluorescent tube 2. A filament 4 facing the inside of the fluorescent tube 2 is attached to the stem mount 3, and a pair of electrode terminals 5 and a tube 6 facing the outside of the fluorescent tube 2 are attached. The tube 6 is used when the inside of the fluorescent tube 2 is evacuated. During the manufacture of the fluorescent lamp 1, the inside and outside of the fluorescent tube 2 are in a communicating state. The inside and the outside of 2 are configured to be in a non-communication state. A mercury flag 7 as an object to be detected is attached to the stem mount 3 so as to face the inside of the fluorescent tube 2. In particular,
The mercury flag 7 is cantilevered by a wire 8 which is a linear member extending from the stem mount 3. Accordingly, the mercury flag 7 is supported in the fluorescent tube 2 at a position eccentric from the center axis of the fluorescent tube 2 in a relatively unstable state.

Next, the outline of the manufacturing process of the fluorescent lamp 1 will be described with reference to FIGS. 7A to 7D. First, the mount fixing for fixing the stem mounts 3 to both ends of the fluorescent tube 2 will be described. The processing is executed. In the mount fixing process, the space between the fluorescent tube 2 and the stem mount 3 is kept airtight, but the inside and outside of the fluorescent tube 2 are communicated via the tube 6.

Thereafter, a vacuum process for connecting the vacuum pump (not shown) to the tube 6 to evacuate the fluorescent tube 2 is performed. In the vacuum processing step, the inside of the fluorescent tube 2 is kept in a vacuum state. Further, in the vacuum processing step, the tube 6 is cut while maintaining the vacuum state, and the tube 6 is cut.
A process for closing the passage is also performed.

Thereafter, as shown in FIG. 7 (d), a heating process for heating the mercury flag 7 by high frequency is performed using the high frequency induction heating device 11 as a heating process means. The high-frequency induction heating device 11 is provided with a power supply 13 in a state where the mercury flag 7 and the high-frequency heating plate 12 as heating means face each other.
Supplies a high-frequency power to the high-frequency heating plate 12 to heat the mercury flag 7. Therefore, mercury is deposited from the mercury flag 7 in the heat treatment step, and the inside of the fluorescent lamp 1 is filled with mercury vapor (mercury gas).

In the heat treatment step, the position where the flat portion of the mercury flag 5 faces the high-frequency heating plate 12;
In other words, the heating efficiency is most improved when they are arranged at positions parallel to each other. For this positioning, a rotation positioning process is performed between the vacuum processing step and the heating processing step. In the rotation positioning process, the position of the mercury flag 7 is detected by rotating the fluorescent lamp 1, and the mercury flag 7 is positioned at a position where the heating efficiency is the highest.

A rotary positioning device 15 including a rotary position detecting device described below is used in the rotary positioning process. Therefore, the rotation positioning device 15
Will be described with reference to FIGS. 1 and 2.

The fluorescent lamp 1 is rotatably supported about a central axis L of the fluorescent tube 2 by a support mechanism having a bearing member (not shown). A feed roller 17 having a rotating shaft 16 parallel to the central axis L is provided on the outer peripheral surface of the fluorescent lamp 1.
Are in contact with each other. A motor 18 is mounted on the rotating shaft 16.
Output shafts are connected. Therefore, the feed roller 17 is rotated in one direction by the driving of the motor 18. on the other hand,
The fluorescent lamp 1 is rotated in the direction opposite to the rotation direction of the feed roller 17 following the rotation of the feed roller 17. Note that the rotating shaft 16 may be replaced with the output shaft of the motor 18, or the rotating shaft 16 and the output shaft of the motor 18 may be indirectly connected via a transmission mechanism such as a speed reducer. .

Around the fluorescent lamp 1, a pair of eddy current type displacement sensors 21 constituting the first detecting means and the second detecting means,
22 (hereinafter, referred to as “first sensor 21” and “second sensor 22”, respectively). Both sensors 21 and 2
Reference numeral 2 denotes a first detection position B and a second detection position B which are rotated in the opposite directions by α degrees in the circumferential direction with respect to the target rotation position A of the fluorescent lamp 1.
It is arranged at each detection position C. First sensor 21
And the second sensor 21 is located 3 mm from the outer peripheral surface of the fluorescent tube 2.
mm and very close equidistant, such as less than mm.

Here, the target rotation position A is the position A
If the surface of the mercury flag 7 is closest to this, the heating efficiency is the highest in the heat treatment step, that is, the position facing the high-frequency heating plate 12 is known in advance, and thus the position is a preset position. In the present embodiment, the target rotation position A is matched with a target detection position to be detected based on the two sensors 21 and 22.

Since the α-degree is required to determine the target rotation position A, the minimum condition is that it is larger than 0 ° and smaller than 90 °. In the present embodiment, α = 45 is set. However, due to the characteristics of both sensors 21 and 22, α is 3
Preferably, it is set in the range of ~ 60. If it is less than 3 degrees, it will be near the peak value and the output change will be small.
This is because when the angle is larger than 0 degree, the output change is small as shown in FIG.

The reason why the first sensor 21 and the second sensor 22 are arranged very close to each other by 3 mm or less from the outer peripheral surface of the fluorescent tube 2 is that the outputs of the two sensors 21 and 22 depend on the rotational position of the mercury flag 7. It is necessary to sufficiently change. That is, if it is larger than 3 mm, there is little change in the analog output from both the sensors 21 and 22 according to the rotational position of the mercury flag 7, and accurate position detection becomes difficult. Further, both sensors 21 and 22 are connected to the fluorescent tube 2.
Are arranged equidistant from the outer peripheral surface of both sensors 21 and
This is because if the analog output characteristics of the two are the same, the same output can be obtained in the relative positional relationship with the mercury flag 7 if they are arranged at the same distance.

The output side of both sensors 21 and 22 is connected to the input side of a comparator 23 as a comparator constituting the comparison means. The comparator 23 includes both sensors 21 and
Compare the magnitude relationship of the analog outputs from 2. An output side of the comparator 23 is connected to an input side of a controller 24 which constitutes a determination unit and a control unit. The controller 24 executes a predetermined operation based on the comparison result input from the comparator 23 and outputs a predetermined control signal. The output side of the controller 24 is connected to the input side of a driver 25 constituting a drive circuit. Driver 2
5 is connected to a motor 18. The driver 25 controls the driving of the motor 18 based on the control signal input from the controller 24.

FIG. 3 shows the positional relationship between the rotation position of the fluorescent tube 2 about the central axis L and the first sensor 21 and the second sensor 22, and the analog output voltage V1 from the first sensor 21 based on the positional relationship. And the analog output voltage V2 from the second sensor 22 and the comparison output from the comparator 23.

As shown in the figure, when the fluorescent tube 2 rotates and the mercury flag 7 reaches the first detection position B, the analog output voltage V1 of the first sensor 21 shows a peak value, and gradually increases on both sides. The analog output voltage V1 decreases. Similarly, when the mercury flag 7 reaches the second detection position C, the analog output voltage V2 of the second sensor 22 shows a peak value, and the analog output voltage V2 gradually decreases on both sides. On the other hand, both analog output voltages V1, V
In No. 2, the change in the voltage value is small near each peak value, whereas the change in the voltage value is large when the distance is slightly away from the peak value. Therefore, in the present embodiment, the angle α degrees (= 45 degrees) is set so that the target rotation position A comes to a portion where the change in the voltage values of both analog output voltages V1 and V2 is large. Therefore, at the target rotation position A, they cross at a point where the change in both analog output voltages V1 and V2 is large. The comparison output from the comparator 23 is
When the mercury flag 7 is disposed closer to the first sensor 21 than the target rotation position A, the output becomes low level,
When the mercury flag 7 is disposed on the sensor 22 side, the output is high.

Hereinafter, the rotation positioning operation will be described with reference to FIGS. When the fluorescent lamp 1 is attached to the rotation positioning device 15, the controller 24
The motor 18 is stopped based on the control signal from. At this time, when the comparison output from the comparator 23 is at a low level, the controller 24 determines that the mercury flag 7 is disposed closer to the first sensor 21 than the target rotation position A.
Is determined by Conversely, when the comparison output from the comparator 23 is at a high level, the controller 24 determines that the mercury flag 7 is located closer to the second sensor 22 than the target rotation position A.

Here, for example, when the comparison output from the comparator 23 is at a low level, the controller 24 controls the driving of the motor 18 so that the fluorescent tube 2 rotates clockwise in FIGS. Conversely, when the comparison output of the comparator 23 is at a high level, the fluorescent tube 2 is rotated to the left. By changing the rotation direction according to the comparison output result in this manner, the fluorescent tube 2 can reach the target rotation position A in the shortest distance (or the shortest time) from the initial position before rotation.

When the fluorescent tube 2 is rotated, the comparison output from the comparator 23 changes over time. For example, when the fluorescent tube 2 is rotated clockwise, the comparison output of the comparator 23 changes from a low level to a high level. This change point is the target rotation position A.

Therefore, the controller 24 constantly monitors the comparison output result from the comparator 23, and outputs a control signal to stop the motor 18 when it recognizes that the comparison output has changed. Thereby, the rotation of the fluorescent tube 2 can be stopped at the position where the mercury flag 7 reaches the target rotation position A. As a result, the high-frequency heating plate 12 of the high-frequency induction heating device 11 and the mercury flag 7 can be accurately opposed to each other in the heating process that is the next process of the positioning process.

The analog output voltage V1 from the first sensor 21 and the analog output voltage V1 from the second sensor 22
Since the magnitude relationship between the two voltages V1 and V2 is switched at a location where the change in the voltage value 2 is large, that is, the target rotational position A is detected, the detection accuracy of the target rotational position A is extremely high. Further, the point of change in the comparison output from the comparator 23 is clear, and there is no waste of time in that the target rotation position A is obtained by a complicated calculation process, and then the fluorescent lamp 1 is rotated again to stop at the target rotation position A. Can be omitted.

Therefore, by using the rotary positioning device 15 described in the present embodiment, the heating efficiency of the mercury flag 7 by the high-frequency induction heating device 11 is improved, and the production efficiency of the fluorescent lamp 1 is improved. In addition, variations in the heating efficiency of each fluorescent lamp 1 can be reduced, and errors between products of the fluorescent lamp 1 can be reduced. Further, the mercury flag 7 can be set at the target rotation position A without rotating the fluorescent lamp 1 a plurality of times.
Can be arranged, so that further improvement in production efficiency can be expected.

The first sensor 21 or the second sensor 2
In some cases, one of the two analog output voltages V1 or V2 is monitored, and a point where a change in the voltage value reaches a predetermined voltage value is a target rotation position A. That is,
The idea is that only one sensor 21 or 22 is used in the present embodiment. However, mercury flag 7
However, since it is originally supported by the wire 8 in a cantilever manner and its position in the fluorescent tube 2 is unstable, the positioning to the target rotation position A becomes inaccurate. In this regard,
According to the present embodiment, the target rotation position A is set at the point where the analog output voltages V1 and V2 of the pair of sensors 21 and 22 intersect.
Is detected, there is an advantage that the target rotation position A can be accurately detected regardless of the position of the mercury flag 7 in the fluorescent tube 2.

The comparison output from the comparator 23 also changes when the fluorescent lamp 1 is rotated 180 degrees from the target rotation position A. However, since this change point is not the original target rotation position A, there is a risk of erroneous detection. Therefore, the analog output voltages V1,
By ignoring the low level side (the anti-peak side) of V2 by the threshold value β, erroneous detection can be prevented. In this case, it is necessary to set at least the threshold value β to a lower level side (opposite peak side) than the voltage values of the two analog output voltages V1 and V2 at the target rotation position A.

[Second Embodiment] Next, a second embodiment will be described with reference to FIGS. The second
In the embodiment, the description of the common parts with the first embodiment will be omitted or simplified, and the description will be focused on the differences from the first embodiment.

In the second embodiment, as shown in FIG. 4, only the first sensor 21 is used, and the second sensor 22 is omitted. As in the first embodiment, the first sensor 21 is disposed at a first detection position B which is rotated from the target rotation position A to one side by α degrees. The second embodiment is most characterized in that the virtual sensor 31 which is not actually installed is regarded as the second sensor 22 and the drive control of the motor 18 is performed. In the present embodiment, the first sensor 21 constitutes a detecting unit.

As shown in FIG. 5, the input side of the A / D converter 32 is connected to the output side of the first sensor 21. A
The / D converter 32 converts the analog output voltage V1 from the first sensor 21 into a digital signal. The output side of the A / D converter 32 is branched, one of which is connected to the input side of a comparator 33 constituting a comparison means, and the other is connected to the input side of a delay circuit 34 comprising a shift register. Have been. Processing means or delay means is constituted by the delay circuit 34. The output side of the delay circuit 34 is connected to the input side of the comparator 33.

When a predetermined digital signal is input, the delay circuit 34 outputs the signal after a predetermined time delay. The delay time is set in advance so that the signal output from the delay circuit 34 with a time delay corresponds to the virtual analog output voltage V11 of the virtual sensor 31. The delay time to be set can be obtained on condition that the rotation speed of the motor 18 is constant. Therefore, FIG.
As shown in (5), the comparison process in the comparator 33 can be executed as if the virtual analog output voltage V11 is actually output from the virtual sensor 31.

The operation after the processing of the controller 24 based on the comparison result of the comparator 33 is almost the same as that of the first embodiment, except for one point. That is, in the first embodiment, the rotation direction of the motor 18 is determined based on whether the comparison output when the motor 18 is stopped for the first time is a high level or a low level. However, in the second embodiment, the mercury flag 7
, Only right rotation of the fluorescent tube 2 in FIG. 4 is allowed. This is obtained as a result of delaying the virtual analog output voltage V11 from the virtual sensor 31 by the time set by the delay circuit 34 using the first analog output V1 of the first sensor 21. Therefore, the delay time of the delay circuit 34 is
This is because the setting is made on the assumption that the clockwise rotation is performed.

Therefore, according to the second embodiment, the same effect as that of the first embodiment can be obtained even though only the single first sensor 21 is used.

Moreover, since only one first sensor 21 is used, the number of sensors can be reduced. In addition, errors due to variations in the characteristics of each sensor, such as when a plurality of sensors are used, and errors due to variations in the relative distance between the sensors and the fluorescent lamp 1 can be eliminated, further improving accuracy. Can be expected. That is, in the case of the present embodiment, it is possible to detect the rotational position with high accuracy as long as the motor 18 can be rotated at a predetermined constant speed.

In the second embodiment, the first sensor 21
Circuit 3 converts the first analog output voltage V1 from the first analog output voltage V1 into a digital signal by an A / D converter 32 and includes a shift register.
4 outputs the virtual analog output voltage V11 to the comparator 33 as a digital signal corresponding to the virtual analog output voltage V11. The virtual analog output voltage V11 is generated by a delay line that constitutes a delay means, and the virtual analog output voltage V11 and the first analog output voltage V11 are generated.
1 may be directly compared.

[Other Embodiments] In the first embodiment, the first
Although a pair of sensors of the sensor 21 and the second sensor 22 is used, three or more sensors may be used. Further, on the condition that an output corresponding to the position of the mercury flag 7 can be obtained, other types of sensors than the eddy current displacement sensors 21 and 22 may be used as the sensors 21 and 22.

In the first embodiment and the second embodiment, the case where the mercury flag 7 of the fluorescent lamp 1 is detected and the rotational positioning of the mercury flag 7 is performed has been described. The present invention can also be applied to the case of detecting a rotational position and performing rotational positioning.

In the first embodiment, the target rotational position A, the first analog output voltage V1 and the second analog output voltage V2
And the target detection position, which is the position of the change point of the magnitude relation of the above. Similarly, in the second embodiment, the target rotational position A
And the target detection position, which is the position of the changing point of the magnitude relationship between the first analog output voltage V1 and the virtual analog output voltage V11. However, the target detection position does not necessarily have to match the target rotation position A. For example, the target detection position is shifted from the target rotation position A by a predetermined angle (for example, 30 to 60).
The mercury flag 7 is accurately set at the target rotation position A even if the motor 18 is stopped after the fluorescent lamp 1 is rotated by the predetermined angle after the target detection position is detected. Can be arranged. The advantage of this method is that the motor 18 is not stopped simultaneously with the determination of the target detection position.
In this case, the inconvenience of stopping beyond the target rotation position A can be avoided as much as possible even when the rotator is rotated at a high speed.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a rotary positioning device according to a first embodiment.

FIG. 2 is a block circuit diagram of the rotary positioning device according to the first embodiment.

FIG. 3 is an explanatory diagram including a graph showing a relationship between a sensor output and a position of a mercury flag and a comparison output according to the first embodiment.

FIG. 4 is a schematic front view of a rotation position detection device according to a second embodiment.

FIG. 5 is a block circuit diagram of a rotary positioning device according to a second embodiment.

FIG. 6 is an explanatory diagram including a graph showing a relationship between an output of a sensor or the like and a position of a mercury flag and a comparison output according to a second embodiment.

7A is a front view of a stem mount constituting a part of a fluorescent lamp, FIG. 7B is a side view of the stem mount,
(C) is a partial perspective view showing a state where a stem mount is attached to a fluorescent tube, and (d) is a schematic front view showing a high-frequency induction heating device.

FIG. 8 is a schematic front view showing a rotational position detecting device for explaining the process leading to the present invention.

FIG. 9 is a graph showing a relationship between a sensor output and a position of a mercury flag for explaining a process leading to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fluorescent lamp, 2 ... Fluorescent tube as a to-be-rotated body, 3 ... Stem mount, 7 ... Mercury flag as a to-be-detected body, 8 ... Wire as a linear member, 11 ... High frequency induction heating apparatus as a heat processing means , 12 ... High frequency heating plate, 15 ... Rotation positioning device, 18 ... Motor, 21 ... First sensor (eddy current displacement sensor) constituting first detecting means or detecting means, 2
2... A second sensor (eddy current type displacement sensor) constituting the second detecting means, 23... A comparator constituting the comparing means, 2
4... A controller constituting a discriminating means and a control means;
DESCRIPTION OF SYMBOLS 1 ... Virtual sensor which is a virtual detection means, 33 ... Comparator which comprises a comparison means, 34 ... Delay circuit (shift register) which comprises a processing means or delay means, L ... Center axis (of a fluorescent lamp), A ... Target Rotational position (= target detection position), B ... first
Detection position, C: second detection position, α: angle, V1, V2 ...
Analog output voltage, V11: virtual analog output voltage.

Claims (15)

[Claims] 1. A rotational position detecting device for detecting that a rotationally driven detection target is disposed at a predetermined target detection position, wherein the detection target is a position separated by a predetermined distance from a rotation center of the detection target. And a first detection unit that is disposed at a position shifted by a predetermined angle from the target detection position to one side and that outputs an output according to a distance from the detection target; and a first detection unit that is separated by a predetermined distance from a rotation center of the detection target. A position that is displaced from the target detection position by the same angle as the predetermined angle from the target detection position, and performs output according to the distance from the object with the same characteristics as the first detection means. A second detecting means, a comparing means for comparing the magnitude relation between the two outputs from the two detecting means, and the target object is positioned at the target detection position when the magnitude relation between the two outputs changes in the comparison result of the comparing means. set on Rotational position detecting device is characterized in that a discriminating means for discriminating to have been. 2. A motor for rotationally driving an object to be detected, a control means for driving and controlling the motor, and a rotational position detection for detecting that the object to be rotationally driven is arranged at a predetermined target detection position. A rotation positioning device comprising: a rotation position detection device, wherein the rotation position detection device is located at a position separated by a predetermined distance from the rotation center of the object to be detected, and is shifted from the target detection position by one predetermined angle to one side. A first detecting means arranged to output an output according to a distance from the object to be detected, and a predetermined distance from a center of rotation of the object to be detected, and from the target detection position to the other of the predetermined position. A second detecting means disposed at a position shifted by an equal angle from the angle and having an identical characteristic to the first detecting means and performing an output according to a distance from the object to be detected; Relationship And a determination unit that determines that the object to be detected is located at the target detection position when the magnitude relationship between the two outputs changes in the comparison result of the comparison unit. When the determination means determines that the detected object is located at the target detection position, the motor stops the detected object at a predetermined target rotation position in relation to the target detection position. A rotation positioning device for controlling stop of the rotation. 3. The control unit determines a rotation direction of the object to be detected based on a comparison result by the comparison unit before the start of rotation of the object to be detected, so that the object rotates in the rotation direction. The rotation positioning device according to claim 2, wherein the motor is drive-controlled. 4. The detection means according to claim 1, wherein the output from the first detection means decreases and the output from the second detection means increases near the position where the object to be detected is located at the target detection position. 2. The apparatus according to claim 1, wherein the predetermined angle is set.
Apparatus according to any of the preceding claims. 5. A rotation position detection device for detecting that an object to be rotationally driven is disposed at a predetermined target detection position, wherein the apparatus is located at a predetermined distance from a rotation center of the object to be detected. And a detection unit arranged at a position shifted by a predetermined angle from the target detection position to one side and performing output in accordance with a distance from the detected object, and at a position separated by a predetermined distance from the rotation center of the detected object So that it is arranged at a position shifted by the same angle as the predetermined angle from the target detection position to the other from the target detection position, so that an output corresponding to the distance from the object to be detected is obtained with the same characteristics as the detection means, Processing means for processing the output of the detecting means; comparing means for comparing the magnitude relation between the outputs from the detecting means and the processing means; and the magnitude relation between the two outputs has changed in the comparison result of the comparing means. Rotational position detecting device object to be detected is characterized in that a discriminating means for discriminating as being disposed in the target position detection at point. 6. A motor for rotationally driving the object to be detected, control means for driving and controlling the motor, and rotational position detection for detecting that the object to be rotationally driven is arranged at a predetermined target detection position. A rotation positioning device comprising: a rotation position detection device, wherein the rotation position detection device is located at a position separated by a predetermined distance from the rotation center of the object to be detected, and is shifted from the target detection position by one predetermined angle to one side. And a detection unit that performs an output in accordance with a distance from the detected object, and a position separated by a predetermined distance from the rotation center of the detected object, and the predetermined angle from the target detection position to the other. Processing means for processing the output of the detecting means so as to be provided at a position shifted by an equal angle and to obtain an output corresponding to the distance from the object to be detected with the same characteristics as the detecting means; Comparing means for comparing the magnitude relation between the two outputs from the means and the processing means, and judging that the object to be detected is located at the target detection position when the magnitude relation between the two outputs changes in the comparison result of the comparing means. A determination unit, wherein the control unit receives the object to be detected at the target detection position by the determination unit, and sets the detection object in advance in relation to the target detection position. A rotation positioning device, wherein the motor is controlled to stop at a predetermined target rotation position. 7. The control means controls the motor to rotate at a constant speed to rotate the object to be detected at a constant speed. The processing means controls the output of the detection means at a predetermined time from the constant rotation of the object to be detected. 7. The rotation positioning device according to claim 6, wherein the rotation positioning device is constituted by delay means for performing the same output after a delay time has elapsed. 8. The rotation positioning device according to claim 6, wherein said control means drives and controls said motor so as to rotate in one direction from said detection means toward a target detection position. 9. An output from said detecting means and an output from said processing means show that the output from the detecting means decreases and the output from the processing means increases near the position where the object to be detected is located at the target detection position. The apparatus according to any one of claims 5 to 8, wherein the predetermined angle is set so that the output from the detecting means increases and the output from the processing means decreases. . 10. The apparatus according to claim 1, wherein, when the predetermined angle is α degrees, α is set within a range of 3 to 60. 11. The rotation positioning device according to claim 2, wherein a target rotation position of the object to be detected is matched with a target detection position. 12. The object to be detected is a mercury flag eccentrically arranged inside a fluorescent tube of a fluorescent lamp, and the mercury flag is rotated by rotating the fluorescent tube around its longitudinal centerline as a rotation center axis. The apparatus according to claim 1, wherein the apparatus determines a detection position. 13. The apparatus according to claim 12, wherein the mercury flag is cantilevered via a linear member to a stem mount attached to an end of the fluorescent tube. 14. The apparatus according to claim 12, wherein said detecting means is arranged at a slight distance outside the outer peripheral surface of the fluorescent tube. 15. A motor which sets a target detection position and a target rotation position so as to be shifted by a predetermined angle, and stops the object to be detected at the target rotation position by the control means after the target detection position is determined by the determination means. The rotational positioning device according to the means 2 or 6, wherein the rotation positioning device is controlled to stop.