JP2011192444A - Discharge tube and strobe device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge tube that prevents a loss of light quantity and prevents peeling-off of a reflecting film from the outer peripheral surface of a glass bulb, and also to provide a strobe device. <P>SOLUTION: The discharge tube 2 is configured such that a reflecting film 10 is formed by metal vapor-deposition on the outer peripheral surface of a cylindrical glass bulb 9. The reflecting film 10 is vapor-deposited in the area of 240&deg; or more in the circumferential direction. The glass bulb 9 has a plurality of recesses 15, ... on the outer peripheral surface so as to prevent peeling-off of the reflecting film 10. The strobe device 1 includes the discharge tube 2. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a discharge tube in which a reflective film is formed by vapor deposition of metal on the outer peripheral surface of a cylindrical glass bulb, and also relates to a strobe device including a light emitting unit having the discharge tube.

  Conventionally, as a discharge tube provided in a light emitting portion of a strobe device, a discharge tube in which a reflective film is formed on the outer peripheral surface of a cylindrical glass bulb so as to leave a band-shaped light transmitting portion that transmits light is known. (For example, Patent Document 1). The reflective film is formed by vapor-depositing a metal such as aluminum or silver, and improves the light emission efficiency by reflecting the light generated in the discharge tube.

JP 7-72535 A

  By the way, the discharge tube 2 emits light toward the outside by the whole gas excited inside the glass bulb 9 emitting light. Therefore, as shown in FIG. 7, in the reflective film 10 deposited in a small range, light emission at the point F is not reflected by the reflective film 10, and is behind the discharge tube 2 (a direction different from the desired direction). Since it is irradiated, the amount of light is lost. Further, in a discharge tube in which a reflective film is formed, there is generally a problem that the reflective film is peeled off from the outer peripheral surface of the glass bulb 9.

  Therefore, in view of such circumstances, an object of the present invention is to provide a discharge tube and a stroboscopic device that can prevent the loss of light amount and can prevent the reflection film from peeling off from the outer peripheral surface of the glass bulb.

  The discharge tube according to the present invention is a discharge tube in which a reflective film is formed by vapor deposition of metal on the outer peripheral surface of a cylindrical glass bulb. In order to prevent the reflective film from peeling off, the outer peripheral surface is provided with a plurality of concave portions.

  According to such a configuration, since the reflective film is deposited in a range of 240 ° or more in the circumferential direction, the light generated inside is reflected by the reflective film, and as a result, it is desired to irradiate a desired direction (to the subject) Direction). Furthermore, since a plurality of recesses are provided on the outer peripheral surface of the glass bulb, the glass bulb and the reflective film are firmly bonded, and as a result, the reflective film can be prevented from being peeled off from the glass bulb.

  In the invention described in claim 2, it is preferable that each recess is formed so that the depth dimension is 1 μm to 10 μm and the width dimension is 2 μm to 40 nm.

  According to such a configuration, each recess is formed such that the depth dimension is 1 μm to 10 μm and the width dimension is 2 μm to 40 μm. Therefore, the reflective film can be firmly bonded to the outer peripheral surface of the glass bulb, and each concave portion can be prevented from affecting optical characteristics.

  A strobe device according to the present invention includes a light emitting unit having the discharge tube.

  According to such a configuration, since the reflection film of the discharge tube is deposited in a range of 240 ° or more in the circumferential direction, the light generated inside the discharge tube is reflected by the reflection film, and as a result, in a desired direction. Light can be irradiated. Furthermore, since a plurality of recesses are provided on the outer peripheral surface of the glass bulb, the glass bulb and the reflective film are firmly bonded, and as a result, the reflective film can be prevented from being peeled off from the glass bulb.

  As described above, according to the discharge tube and the strobe device according to the present invention, since light is irradiated in a desired direction, loss of the light amount can be prevented, and the glass bulb and the reflection film are firmly bonded. There is an excellent effect that the reflective film can be prevented from peeling off the glass bulb.

1 is an overall perspective view of a strobe device according to an embodiment of the present invention. In the discharge tube according to the same embodiment, (a) is an overall perspective view, and (b) is an enlarged view of region A. An internal front view for explaining a method of manufacturing a discharge tube according to the embodiment The perspective view explaining the manufacturing method of the discharge tube concerning the embodiment In the figure explaining the manufacturing method of the discharge tube concerning the embodiment, (a)-(c) is a sectional view. Correlation diagram between reflective film thickness and reflectance of discharge tube according to the same embodiment Overall cross-sectional view of a conventional discharge tube

  Hereinafter, an embodiment of a strobe device and a discharge tube according to the present invention will be described with reference to FIGS.

  The strobe device 1 according to the present embodiment is provided in an imaging device (not shown). As shown in FIG. 1, the strobe device 1 includes a discharge tube 2 that emits light, a reflection member 3 that reflects light emitted from the discharge tube 2 toward the subject, a discharge tube 2 and a reflection member. And a holder 4 for holding 3. Further, the strobe device 1 includes an optical member 5 that accommodates the holder 4 in a state that a part thereof is translucent and holds the discharge tube 2 and the reflection member 3.

  Further, the strobe device 1 includes a panel substrate 6 fixed to the optical member 5 so as to cover the optical member 5. Further, the strobe device 1 includes a trigger coil (not shown) mounted on the panel substrate 6 and various electronic components 7..., And an auxiliary light source (LED that functions as auxiliary light when performing autofocusing. 8).

  As shown in FIG. 2, the discharge tube (flash discharge tube) 2 includes a long cylindrical glass bulb 9 and a reflective film 10 formed on the outer peripheral surface of the glass bulb 9 by vapor deposition of metal. In addition, the discharge tube 2 arrange | positions the reflective film 10 in the partial range of the circumferential direction, the translucent strip | belt-shaped translucent part 11 is arrange | positioned in the front side of the glass bulb 9, and the translucent part 11 is arranged. The light generated inside is irradiated to the outside. The discharge tube 2 includes electrodes 13 and 14 at each end 12 in the longitudinal direction.

  The glass bulb 9 includes a plurality of recesses 15 on the outer peripheral surface in order to prevent the reflective film 10 from peeling off. Each recess 15 is formed with a depth dimension of 1 μm or more. Each recess 15 is preferably formed to have a depth dimension of 1 μm to 10 μm and a width dimension of 2 μm to 40 μm. Further, at least one recess 15 is formed on the outer peripheral surface of the glass bulb 9 in a 100 nm square.

  The reflective film 10 is deposited on the outer peripheral surface of the glass bulb 9 over the entire length in the axial direction. The reflective film 10 is deposited on the outer peripheral surface of the glass bulb 9 in a range of 240 ° or more in the circumferential direction.

  The configurations of the strobe device 1 and the discharge tube 2 according to the present embodiment are as described above. Next, a method for manufacturing the discharge tube 2 according to the present embodiment will be described.

  First, the outer peripheral surface of the glass bulb 9 is cleaned before metal deposition. First, the outer peripheral surface of the glass bulb 9 is ultrasonically cleaned for about 5 minutes in a first pure water tank in which pure water is stored (preliminary cleaning step). Next, the outer peripheral surface of the glass bulb 9 is ultrasonically cleaned for about 60 minutes in a hydrofluoric acid tank in which hydrofluoric acid (50% concentration solution) is stored (hydrofluoric acid cleaning step). Then, the hydrofluoric acid is washed away by ultrasonically cleaning the outer peripheral surface of the glass bulb 9 for about 5 minutes each in the second and third pure water tanks in which pure water is stored.

  At this time, the hydrofluoric acid adhering to the outer peripheral surface of the glass bulb 9 is washed away to some extent by washing in the second pure water tank (preliminary rinsing process), and then washing in the third pure water tank (final rinsing process). Thus, the hydrofluoric acid adhering to the outer peripheral surface of the glass bulb 9 is completely washed away. Thereby, a plurality of recesses 15 are formed on the outer peripheral surface of the glass bulb 9.

  Next, a vacuum deposition apparatus for performing metal deposition on the outer peripheral surface of the glass bulb 9 in which the plurality of recesses 15 are formed will be described with reference to FIG.

As shown in FIG. 3, the vacuum vapor deposition device 16 includes a vapor deposition jig 17 for fixing the glass bulbs 9,... To form the reflective film 10 by vapor-depositing metal on the outer peripheral surface of the glass bulb 9.
The vapor deposition jig 17 is installed in the vacuum chamber 18 after fixing the glass bulb 9. Further, the vapor deposition jig 17 can fix a plurality of glass bulbs 9 from the viewpoint of productivity.

  The vapor deposition jig 17 is attached to a rotary stage 19 disposed above the vacuum chamber 18. A metal deposition source 20 that is deposited on the glass bulbs 9 to form the reflective film 10 is installed below the vacuum chamber 18. In addition, as the vapor deposition source 20, aluminum, silver, or the like is used.

  According to such a configuration, the rotation source 19 rotates around the axial direction of the glass bulb 9 fixed by the vapor deposition jig 17 (in the direction of the arrow B in FIG. 3), so that the vapor deposition source in the glass bulb 9 is obtained. The position of the outer peripheral surface facing 20 can be changed.

  Then, after the glass bulbs 9 and the vapor deposition source 20 are installed in the vacuum chamber 18, the vacuum chamber 18 is evacuated. Thereafter, when the vapor deposition source 20 is heated, the metal material evaporates toward each glass bulb 9 (in the direction of arrow C in FIG. 3), so that the reflective film 10 is formed on the outer peripheral surface of each glass bulb 9.

  Next, a method for fixing each glass bulb 9 to the vapor deposition jig 17 and a method for installing the vapor deposition jig 17 in the vacuum chamber 18 will be described with reference to FIG.

  As shown in FIG. 4, the vapor deposition jig 17 is provided with a plurality of long mask jigs 22 on a base plate 21. And after arrange | positioning the glass bulb | ball 9 to each jig | tool 22 for masks so that a mutual longitudinal direction may become parallel, the edge part of each glass bulb | bulb 9 is hold | suppressed with the pressing plate 23. FIG. Further, the presser plate 23 is fixed to the mounting portion 24 on the base plate 21 via a screw 25 so as to maintain a state in contact with the end portion of each glass bulb 9.

  Then, after the mask jigs 22 and the glass bulbs 9 are fixed on the base plate 21, the glass bulbs 9 are positioned below the mask jigs 22 (the orientation and the vertical direction in FIG. 4). In a state where the direction is reversed), the vapor deposition jig 17 is installed in the vacuum chamber 18 of the vacuum vapor deposition apparatus 16.

  The mask jigs 22,... Are provided for providing a portion where the reflective film 10 is not formed on the outer peripheral surface of the glass bulb 9, that is, a portion that becomes a band-like light transmitting portion 11 through which light is transmitted. . Further, the pressing plate 23 fixes the mask jigs 22,... And the glass bulbs 9, and prevents film formation on the electrodes 13 disposed at the ends of the glass bulbs 9,. Yes.

  Next, a method of forming the reflective film 10 on the outer peripheral surface of the glass bulb 9 by depositing metal on the glass bulb 9 will be described with reference to FIG.

  First, the rotation angle of the rotary stage 19 is set, and vapor deposition is performed on the glass bulb 9 in the first direction (the direction of arrow D in FIG. 5A) in which the glass bulb 9 and the vapor deposition source 20 face each other. At this time, the reflective film 10 is formed in a range of about 180 ° in the circumferential direction around the portion of the outer peripheral surface of the glass bulb 9 located in front of the vapor deposition source 20.

  Further, the reflective film 10 is formed so as to gradually become thinner from a portion of the outer peripheral surface of the glass bulb 9 which is located in front of the vapor deposition source 20 toward the back side. In addition, since the metal material does not adhere to the portion of the outer peripheral surface of the glass bulb 9 covered with the mask jig 22, the reflective film 10 is not formed.

  Next, when the rotary stage 19 is rotated, the portion where the glass bulb 9 is located in front of the vapor deposition source 20 moves about 90 °, and is orthogonal to the first direction as shown in FIG. In the second direction (E arrow direction in FIG. 5B), vapor deposition is performed on the glass bulb 9.

  Similarly, the reflective film 10 is formed in a range of about 180 ° in the circumferential direction around the portion of the outer peripheral surface of the glass bulb 9 that is located in front of the vapor deposition source 20. The reflective film 10 is formed so as to gradually become thinner from the portion located on the front surface with respect to the vapor deposition source 20 to the rear surface side of the outer peripheral surface 9.

  Then, by performing the above procedure at least twice (multiple times depending on the required film thickness), the metal material is deposited on the entire outer peripheral surface of the glass bulb 9 that is not covered with the mask jig 22. Thereby, it is possible to form the reflective film 10 having a deposition angle exceeding 180 °.

  On the outer peripheral surface of the glass bulb 9, there is an overlapping portion 26 where the reflective film 10 is formed in both the vapor deposition from the first direction and the vapor deposition from the second direction. As shown in FIG. 5C, the reflective film 10 is formed such that the overlapping portion 26 is formed to be the thickest and the film thickness gradually decreases toward the light transmitting portion 11 side.

  FIG. 6 shows the reflectance of the reflective film 10 formed on the discharge tube 2 (average value when the reflective film 10 is formed using silver as the vapor deposition source 20 and the spectral reflectance in the emission wavelength range of 400 to 700 nm is measured. ) And the thickness of the reflective film 10.

  Based on the above results, in this embodiment, the reflective film 10 is deposited so that the thickness is at least 50 nm or more, preferably 100 nm or more. If the thickness of the reflective film 10 is 50 nm or more, the reflectance (92%) is substantially the same as that of the reflective member (reflector umbrella) used in the conventional strobe device, and therefore, it occurs in the discharge tube 2. Light can be sufficiently reflected.

  Furthermore, each end portion (front side portion) in the circumferential direction of the reflective film 10 that is easily peeled is formed with a film thickness of 50 nm or more that is thin enough that the reflectance does not decrease, while the central portion in the circumferential direction of the reflective film 10 The (rear side part) is formed so as to have a film thickness of 100 nm or more in order to prevent the metal particles from being scattered due to impact or heat at the time of light emission of the discharge tube 2 and to prevent a decrease in the amount of reflected light. Is preferred.

  In addition, when it is desired to set the entire reflective film 10 to have a higher reflectance than that of the conventional reflective member (reflector umbrella), it is preferable to form the film at least 80 nm or more. And since the reflective film 10 of the rear part of the discharge tube 2 becomes a film thickness of 100 nm or more by said vapor deposition method, a reflectance becomes substantially the same (about 96%) over the circumferential direction, and can be averaged. As a result, light distribution unevenness can be suppressed.

  By the way, the angle in the circumferential direction of the light transmitting portion 11 (hereinafter also referred to as “opening angle”) is equal to or less than a certain value, that is, the light transmitting portion 11 is closer to the inner peripheral edge of the discharge tube 2 in the optical axis direction of the discharge tube 2. When it is located on the front side, the light generated in the discharge tube 2 can be prevented from irradiating backward.

Here, when the opening angle at such a position is 2θ, the outer radius of the discharge tube is R1, and the inner radius of the discharge tube is R2,
cos θ = R2 / R1
Therefore, it is necessary to make θ equal to or less than a certain value in accordance with the ratio between the outer radius R1 and the inner radius R2 of the discharge tube. Therefore, an example of the deposition angle of the reflective film 10 is shown in the following Table 1 based on the dimensions (types 1 to 9) of a thin flash discharge tube that is generally manufactured.

例えば、タイプ９であれば、外径＝１．３０ｍｍより、Ｒ１＝０．６５ｍｍとなり、また、内径＝０．８５ｍｍより、Ｒ２＝０．４２５となり、その場合、２θ＝９８．３°となる。したがって、透光部１１が放電管２の光軸方向で放電管２の内径縁部よりも前方側に位置するには、開口角度をこの値（２θ）以下にする必要があるため、反射膜１０を形成する蒸着角度を３６０°（全角度）−９８．３°（開口角度）＝２６１．７°以上にしなければならない。

For example, in the case of Type 9, R1 = 0.65 mm from outer diameter = 1.30 mm, and R2 = 0.425 from inner diameter = 0.85 mm. In this case, 2θ = 98.3 °. . Therefore, in order for the translucent portion 11 to be positioned in front of the inner diameter edge of the discharge tube 2 in the optical axis direction of the discharge tube 2, the opening angle needs to be equal to or smaller than this value (2θ). 10 should be 360 ° (all angles) −98.3 ° (opening angle) = 261.7 ° or more.

  In consideration of the relationship between the outer diameter and inner diameter of various discharge tubes 2 that are used in practice, and manufacturing errors (part tolerances) of the discharge tube 2, the range for forming the reflective film 10 is set to 240 ° or more. Is preferred.

  As described above, according to the strobe device 1 according to the present embodiment, since the reflection film 10 of the discharge tube 2 is deposited in a range of 240 ° or more in the circumferential direction, the light generated inside the discharge tube 2 is reflected by the reflection film. 10 is reflected. Thereby, since light can be irradiated in a desired direction, it is possible to prevent loss of light quantity.

  Further, according to the strobe device 1 according to the present embodiment, a plurality of recesses 15 are provided on the outer peripheral surface of the glass bulb 9 of the discharge tube 2. As a result, for example, the contact area between the glass bulb 9 and the reflective film 10 is increased, or the glass bulb 9 and the reflective film 10 are locked together, so that the glass bulb 9 and the reflective film 10 are firmly bonded. As a result, the reflective film 10 can be prevented from being peeled off from the glass bulb 9.

  Note that the strobe device and the discharge tube according to the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Moreover, it is needless to say that configurations, methods, and the like according to various modifications described below may be arbitrarily selected and employed in the configurations, methods, and the like according to the above-described embodiments.

  For example, in the discharge tube 2 according to the present invention, the reflective film 10 may be formed by being deposited in a range where the central portion is larger than the end portions 12 in the axial direction. In this case, the translucent part 11 should just exist over the full length of the reflective film 10 in the axial direction. For example, the range in which the reflective film 10 is deposited on the end 12 is 240 ° or more, and the range in which the reflective film 10 is deposited on the central portion 14 (center position 15) is larger than the end 12 and smaller than 360 °. That's fine.

  Moreover, in the manufacturing method of the discharge tube 2 according to the present invention, the reflecting member 3 is used as a mask jig 22 at the time of vapor deposition, and the discharge tube 2 and the reflecting member 3 are combined and fixed to the vapor deposition jig 17. Alternatively, the reflective film 10 may be deposited. According to such a manufacturing method, the reflective film 10 can be molded more easily at an appropriate vapor deposition angle.

  Moreover, in the manufacturing method of the discharge tube 2 according to the above embodiment, the rotary stage 19 is rotated in order to change the angle from the vapor deposition source 20 with respect to the outer periphery of the glass bulb 9, but this is not the only case. . For example, the glass bulbs 9 may be rotated individually one by one, or the evaporation source 20 may be moved to change the angle with respect to the outer periphery of the glass bulb 9.

  Moreover, in the manufacturing method of the discharge tube 2 according to the above-described embodiment, the case where the vapor deposition is performed by the vacuum vapor deposition method has been described. However, the present invention is not limited to such a case. But you can.

  Since the discharge tube and the strobe device according to the present invention irradiate light in a desired direction, it is possible to prevent the loss of the light amount, and the outer peripheral surface of the glass bulb that firmly bonds the outer peripheral surface of the glass bulb and the reflective film. It is effective as a discharge tube in which a reflection film is formed by vapor deposition of metal on the outer peripheral surface of a cylindrical glass bulb, and a strobe device equipped with the discharge tube.

DESCRIPTION OF SYMBOLS 1 Strobe device 2 Discharge tube 3 Reflective member 4 Holder 5 Optical member 6 Panel substrate 7 Electronic component 8 Auxiliary light source 9 Glass bulb 10 Reflective film 11 Translucent part 12 End part 13 Electrode 14 Electrode 15 Recessed part 16 Vacuum deposition apparatus 17 Deposition jig 18 Vacuum chamber 19 Rotating stage 20 Deposition source 21 Base plate 22 Mask jig 23 Holding plate 24 Mounting portion 25 Screw 26 Overlapping portion

Claims (3)

In a discharge tube in which a reflective film is formed by vapor deposition of metal on the outer peripheral surface of a cylindrical glass bulb, the reflective film is deposited in a range of 240 ° or more in the circumferential direction, and the glass bulb prevents the reflective film from peeling off. Preferably, the discharge tube is provided with a plurality of recesses on the outer peripheral surface. 2. The discharge tube according to claim 1, wherein each recess is formed to have a depth of 1 μm to 10 μm. A strobe device comprising a light emitting unit having the discharge tube according to claim 1.

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