JP3022275B2 - Variable illumination angle flash device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination angle variable flash device which can change an illumination angle of a light source with respect to an object to be irradiated.

[0002]

2. Description of the Related Art Conventionally, when a subject is photographed by a photographing device such as a camera, an illumination angle variable strobe or the like, which can change an irradiation angle according to a photographing angle of view of a photographing lens to be used, for illumination of the subject. Variable-angle flash devices are often used.

One example of a conventional flash device with variable irradiation angle is disclosed in Japanese Patent Application Laid-Open No. 55-129326. As shown in FIG. The Xe tube 52, which is a light source located at La,
As shown in FIG. 5B, the distance Lb from the reflector 53 on the optical axis K is determined according to the angle of view of the shooting lens used.
The Xe tube 52 is moved to the position
It is known that the positional relationship between the light source and the reflecting umbrella 53 is changed to change the irradiation angle with respect to the subject.

The structure near the reflector 53 of the variable irradiation angle flash device is shown in FIG. 6, and the Xe tube 52 is supported by a side wall 62 via a rubber bush 64.

[0005]

However, as shown in FIG. 7, for example, as shown in FIG. 7, the conventional flashing device with variable irradiation angle has electrodes 73, 74 at both ends of a glass tube in which xenon gas is sealed. Is the effective light emitting portion of the Xe tube 71 having a sealed structure, that is, the length obtained by adding the distances L2 and L3 from the tips of the electrodes 73 and 74 to the corresponding sealing portions to the effective light emitting length L1 of the Xe tube 71. Part L
The following inconveniences may occur when considering a structural development in which the light emitted from the tube 71 is effectively irradiated onto the subject without waste, and the light is introduced into the reflector umbrella 72 in order to increase the utilization efficiency of the emitted light. become.

Although the above-mentioned conventional flashing device with variable irradiation angle is not disclosed in detail, the electrode of the Xe tube 52 is held by the holding structure of the Xe tube 52 by the rubber bush 64 and the side wall 62 as shown in FIG. Specifically, the output of the trigger coil is applied to the Xe tube 52 via the trigger band, and further, the Xe tube is Discharge to the conductive part in the reflector 53 via the Nesa coating of 52,
Discharge from the conductive part to the electrode of the Xe tube 52, and X
It is conceivable that the distance between the two tubes is sufficiently large so as not to cause a problem that the e-tube 52 does not emit light.

On the other hand, when the above-described structural development shown in FIG. 7 is performed, the conductive portion in the reflector 72 and the electrodes 73 and 74 of the Xe tube 71 necessarily come close to each other. Usually, as a distance that does not cause the discharge of the trigger output between the conductive part in the reflector and the electrode of the Xe tube, a distance of 4 mm or more is required when the output of the trigger coil is about 5 KV, for example. The distance between the conductive part in the reflector 72 and the electrodes 73 and 74 is very easily 4 m.
m, and as a result, the output of the trigger coil is discharged to the electrodes 73 and 74 via the conductive portion in the reflector 72, and the output can perform the original operation of exciting the Xe tube 71. There is a risk that the Xe tube 71 will not emit light and will not emit light.

That is, the structure of holding the Xe tube in the conventional flash device with variable irradiation angle is unknown in detail,
While the structure is such that unnecessary discharge does not occur between the electrode of the tube and the conductive part in the reflector, the structural development shown in FIG. This is a development in a direction in which unnecessary discharge easily occurs. Therefore, when the conventional development of the flash angle variable flash device is to be performed as shown in FIG. 7, the holding structure of the Xe tube 52 basically has a structure. In view of only the above-mentioned structural development, there is a disadvantage that unnecessary discharge as described above occurs depending on the relationship between the electrode of the Xe tube 52 and the conductive portion in the reflector 53. Have the potential to occur.

The present invention has been made in consideration of the above-mentioned problems, and even when the distance between the electrode of the Xe tube as a light source and the conductive portion in the reflector becomes short, the trigger output between the electrodes is reduced. A light source that does not generate unnecessary discharge called discharge, that is, a light source suitable for developing a structure in which the Xe tube whose effective light emitting portion is placed in a reflector to move the Xe tube in order to increase the use efficiency of emitted light changes the emission angle. Provided is an illumination angle variable flash device provided with a holding structure.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a variable irradiation angle flash device according to the present invention has a glass tubular body having electrodes at both ends and emitting a flash from the glass tube portion, and a light source. A reflector that reflects flash light from the light source to the irradiation target, and changes the distance on the optical axis between the light source and the reflector to adjust the irradiation angle of the flash light from the light source to the irradiation target. The variable flash device includes a light source holding unit that moves in the optical axis direction while holding the light source to change the distance between the light source and the reflector, and sets the light source based on an effective light emitting length of a glass tube portion thereof. The outer portion and the electrode portion are configured to be covered with a heat-shrinkable tube, and have a light source holding structure in which the light source holding portion holds the heat-shrinkable tube and the glass tube of the light source on the glass tube.

According to the above construction, the light source holding portion holds both ends of the glass tube portion of the light source via the heat-shrinkable tube. Avoid the effects of eccentricity on the tube.

A heat-shrinkable tube covers a portion outside the effective light emission length of the light source, and is further held by the light-source holding portion, thereby preventing the heat-shrinkable tube and the light-source holding portion from being deformed or burnt by the heat of the glass tube surface. I do.

In addition, since the light source is covered with a heat-shrinkable tube outside the effective emission length and the electrode portion,
Even if the heat-shrinkable tube is broken at the holding portion of the light source, unnecessary discharge is prevented except between the electrodes of the light source.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A variable irradiation angle flash device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the vicinity of a reflector of a flash device with variable illumination angle according to the present embodiment. In FIG. 1, 1
Is a reflection umbrella, 2 is a Xe tube holding member as a light source holding unit, 3
Represents an Xe tube, 4 represents a heat-shrinkable tube (shaded portion), and 10 represents a trigger lead.

In FIG. 2, 3 is a Xe tube, 4 is a heat shrink tube, 2 is a Xe tube holding member, 3a is a cathode electrode of the Xe tube 3, and 3b is an anode electrode of the Xe tube 3. First,
In FIG. 1, a Xe tube holding member 2 is made of polyetherimide, and holds both ends of a glass tube portion of a Xe tube 3 via a heat shrink tube 4 at holding portions 2a.

That is, when considering the development of the structure for improving the utilization efficiency of the light emitted from the Xe tube 3 as shown in FIG. 7 described above, the holding place of the Xe tube 3 should be as far as possible the end, for example, the electrode. It is desired to hold the portions 3a and 3b, while the electrodes 3a and 3b of the Xe tube 3 are desired.
Is not always located at the center of the glass tube because both ends of the glass tube are sealed by melting the glass tube. In other words, the electrodes 3a and 3b are biased with respect to the glass tube. There is a case where the electrodes 3a and 3b of the Xe tube 3 are configured as described above.
The Xe tube 3 is not affected by the eccentricity of the electrodes 3a and 3b with respect to the glass tube as compared with the structure holding the portions.
Can be maintained, and the positional accuracy between the Xe tube 3 and the reflector 1 can be improved.

Therefore, it is possible to reduce the variation of the irradiation angle with respect to the subject between the individual devices. As shown in FIG. 2, the heat-shrinkable tube 4 has an end portion of the Xe tube 3 outside the effective emission length Ls of the Xe tube 3 and the electrodes 3a, 3a.
b, that is, the heat-shrinkable tube 4 does not enter the effective emission length Ls region in a state where the end on the Xe tube 3 side does not enter the effective emission length Ls region in consideration of a heat generation state based on the light emission operation of the Xe tube 3 described later. The Xe tube holding member 2 is arranged so that the holding portion of the Xe tube by the holding portion 2a is located outside the effective emission length Ls of the Xe tube 3. Since the Xe tube 3 is held, the heat-shrinkable tube 4 and the Xe tube holding member 2 can be prevented from being deformed or burnt by heat.

A light emission experiment for showing this will be described below with reference to FIG. In this light emission experiment, the main condenser capacity = 1300 μF, the effective light emission length of the Xe tube 3 = 28 mm,
The case where the outer diameter of the glass tube of the Xe tube 3 is 3.5 mm will be described as an example.

As a result of the light emission experiment under the above conditions, it was found that the surface of the Xe tube 3 shown in FIG.
The temperature of about 283 ° C. or more is 49 ° C. or less, the temperature of about 283 ° C. or more is about 260 to 270 ° C. On the other hand, the ignition temperature of polyethylene, which is the material of the heat-shrinkable tube 4, is about 341 ° C., and the ignition temperature is 34.
9 ° C., so that the Xe tube 3
By making the area that covers the area as described above,
It is possible to prevent the heat shrink tube 4 from being deformed or burned. Also, it was confirmed that if the material of the Xe tube holding member 2 was polyetherimide (heat resistance of about 200 ° C.) or the like, there was no thermal deformation or burning.

Therefore, the Xe tube 3 by the Xe tube holding member 2
It is possible to prevent a change in the irradiation angle with respect to the subject caused by the temporal change of the holding state. Next, the operation of the present embodiment for the unnecessary discharge described at the beginning, that is, the so-called trigger jump phenomenon in which the trigger output discharges to the electrode of the Xe tube 3 via the conductive portion of the reflector, FIG.
This will be described with reference to (a) and (b).

FIG. 4A is an enlarged schematic view of a cathode portion of the Xe tube 3 as a light source at the time of telephoto when performing telephoto photographing, and FIG. 4B is a diagram illustrating the Xe tube 3 at wide time when performing wide-angle photographing. FIG. 2 is an enlarged schematic view of a cathode portion. In each drawing, constituent members having the same reference numerals as those in FIG. 1 and the like indicate the same constituent members, and in each drawing, the Xe tube holding member 2 and the heat shrinkable tube 4 in FIG. 1 are omitted. ing.

In FIG. 4A, reference numeral 3a denotes a cathode electrode of the Xe tube 3, reference numeral 5 denotes a portion where the heat shrink tube 4 is assumed to be broken by the Xe tube holding member 2, and reference numeral 1a denotes a portion 5 where the heat shrink tube 4 is assumed to be broken. Shortest distance from the conductive portion 1 of the reflector 1 to the cathode electrode 3a of the Xe tube 3 via the
4 schematically shows the shortest distance from the conductive portion 1 of the reflector 1 to the cathode electrode 3a of the Xe tube 3 when the heat shrink tube 4 is not provided.

In FIG. 4 (b), 1a 'and 1b'
4A corresponds to 1a and 1b, respectively. Xe tube 3
Assuming that there is no heat shrink tube at both ends of FIG.
In (a), the point 1b of the reflector 1 → the cathode electrode 3
Since the distance of the route a is short, a trigger jump occurs. Also in FIG. 4B, a trigger jump occurs because the distance from the point 1b ′ of the reflector 1 to the cathode electrode 3a is short.

On the other hand, as shown in FIG. 1, if the heat-shrinkable tube 4 is in a normal state, the heat-shrinkable tube 4 is insulative. → Reflector 1 → Cathode 3
The route a can be considered, but in this route,
Since a distance of 4 mm or more can be sufficiently secured between the reflector 1 and the cathode electrode 3a, unnecessary trigger jump does not occur.

However, in FIG. 1, the Xe tube 3 holding structure has a structure in which the Xe tube holding member 2 sandwiches the glass portion of the Xe tube 3. Tension may be applied, and the film of the heat-shrinkable tube 4 may be broken.

As described above, the heat shrink tube 4 is connected to the Xe tube 3
Even if it is assumed that the holding portion a is torn,
In the tele time shown in (a), the hatched portion 5 becomes a break in the heat-shrinkable tube 4, but the trigger coil → the point 1a of the reflector 1 → the break 5 in the heat-shrinkable tube 4 → the cathode electrode 3a.
In this route, the total creepage distance from the point 1a of the reflector 1 to the cathode electrode 3a is 4 mm or more, so that the output of the trigger coil is the cathode electrode 3a of the Xe tube 3.
Does not discharge to

Also in the wide state shown in FIG. 4B, the hatched portion 5 becomes a break in the heat-shrinkable tube 4, but the trigger coil → point 1a ′ of the reflector 1 → the break 5 in the heat-shrinkable tube 4 → Since the total creepage distance from the point 1a 'of the reflector 1 to the cathode electrode 3a in the route of the cathode electrode 3a is 4 mm or more, the output of the trigger coil does not discharge to the cathode electrode 3a of the Xe tube 3.

As described above, unnecessary discharge except between the electrodes of the Xe tube 3 can be prevented. In the above-described embodiment, the movement of the Xe tube on the optical axis by the Xe tube holding member may be either an electric drive system by a motor or a manual drive system by a user, and both may be similarly performed. be able to.

[0030]

As described above, according to the present invention, the light source holding portion holds both ends of the glass tube portion of the light source via the heat-shrinkable tube, so that the light source and the reflector can be positioned relative to each other. Can be prevented from being affected by the eccentricity of the electrode with respect to the glass tube.

Therefore, it is possible to improve the positional accuracy between the light source and the reflector, and to reduce the variation in the irradiation angle with respect to the subject between the individual devices. Also, the light source holding portion holds the outer portion of the light source outside the effective emission length, so that the heat-shrinkable tube and the light source holding portion have:
Prevents deformation and burning of the glass tube surface due to heat.

Therefore, it is possible to prevent a change in the irradiation angle with respect to the subject caused by a temporal change in the holding state of the light source by the light source holding section. In addition, since the light source has a portion outside the effective emission length and an electrode portion covered with a heat-shrinkable tube, even if the heat-shrinkable tube is broken at the holding portion of the light source, unnecessary discharge is generated only between the electrodes of the light source. To prevent

Therefore, a discharge can be obtained only between the electrodes of the light source.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram of a variable irradiation angle flash device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a Xe tube in the embodiment.

FIG. 3 is an explanatory diagram of a light emission experiment of a Xe tube in the embodiment.

FIG. 4 is an enlarged view of the vicinity of a cathode electrode showing the embodiment.

FIG. 5 is a configuration diagram of a main part of a conventional flash device with variable irradiation angle.

FIG. 6 is a block diagram showing the vicinity of a reflector of the variable illumination angle flash device of the conventional example.

FIG. 7 is a block diagram showing the vicinity of a reflector of another conventional variable illumination angle flash device.

[Explanation of symbols]

 2 Xe tube holding member 3 Xe tube 4 Heat shrink tube

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03B 15/04-15/05

Claims (2)

(57) [Claims] 1. A light source having electrodes at both ends of a glass tubular body and emitting a flash from the glass tube, and a reflector for reflecting the flash from the light source to an irradiation target. In the irradiation angle variable flash device that changes the distance on the optical axis with respect to the light axis and adjusts the irradiation angle of the flash from the light source to the irradiation target, the light source moves in the optical axis direction while holding the light source, And a light source holding portion for changing the distance between the light source and the reflector, the light source comprising a portion outside the effective emission length of the glass tube portion and an electrode portion covered with a heat shrinkable tube, and a heat shrinkable tube of the light source. An illumination angle variable flash device having a light source holding structure in which a light source holding portion holds the light source above the glass tube. 2. An effective light-emitting portion obtained by adding the effective light-emitting length from the tip of the electrode to the inner end face of the glass tube to increase the efficiency of using light emitted from the Xe tube having electrodes at both ends of the glass tube. In the irradiation angle variable flash device which is put in an umbrella and moves the Xe tube to change the emission irradiation angle,
In order to prevent unnecessary discharge between the electrode of the Xe tube and the conductive portion in the reflector, and to function to improve the positional accuracy of the Xe tube relative to the reflector when the Xe tube moves. A holding structure for covering the glass tube from an end region outside the effective light emission length to an appropriate region of the electrode with a heat-shrinkable tube, and further holding an end region of the glass tube covered with the heat-shrinkable tube. Variable illumination angle flash device equipped with.