Off-camera flash apparatus

Abstract

An off-camera flash apparatus (18) for photographic purposes is described. The flash apparatus (18) comprises a housing (2) with a length axis (L), a flash generator (3) arranged at a first end (17) of the flash housing (2) along the length axis (L) and configured to generate a flash light emitted from the flash apparatus (18), and a modelling light generator (4) arranged at the first end (17) of the flash housing (2) and configured to generate a modelling light emitted from the flash apparatus (18). The flash apparatus (18) has a blocking member (6) which is configured to block flash light from the flash generator (3), which is directed towards the modelling light generator (4).

Description

[0001] OFF-CAMERA FLASH APPARATUS

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to an off-camera flash apparatus for photographic purposes. More specifically the present disclosure relates to an off-camera flash apparatus comprising a housing with a length axis, and a flash generator configured to generate a flash light. The flash apparatus also comprises a modelling light generator configured to generate a modelling light.

[0004] BACKGROUND ART

[0005] Off-camera flash apparatuses for photographic purposes are used widely by professional photographers, and especially by studio photographers. Such flash apparatuses have a flash generator configured to generate a flash light. When arranging the scene to be captured it is helpful if the flash apparatus has a modelling light generator. During illumination with the modelling light from the model light generator it is possible to visualize how shadows will be when illuminating with the flash generator. This allows adjustment of the relative position of the modelling light generator, and thereby the flash apparatus, in relation to the subjects before capturing an image of the subject using the flash generator. The modelling light may also be used during filming. The term off-camera flash is used for flash apparatuses that are configured to be used unattached to a camera.

[0006] SUMMARY OF THE INVENTION

[0007] An objective of the present application is to provide a flash apparatus as described above, which enables the use of heat sensitive modelling light generators together with high power flash generators. This objective is fulfilled with a flash apparatus according to the independent claim.

[0008] Additional advantages are provided by the features of the dependent claims.

[0009] According to a first aspect, an off-camera flash apparatus for photographic purposes is provided. The flash apparatus comprises a housing with a length axis, a toroidal Xenon flash tube arranged at a first end of the flash housing along the length axis and configured to generate a flash light emitted from the flash apparatus. The flash apparatus also comprises a modelling light generator arranged at the first end of the flash housing and configured to generate a modelling light emitted from the flash apparatus. The flash apparatus is characterized in that

[0010] - the modelling light generator comprises a plane light emitting surface which is perpendicular to the length axis,

[0011] - the toroidal Xenon flash tube defines a centre plane which is perpendicular to the length axis, and which is downstream the light emitting surface of the modelling light generator in the light emission direction of the light emitting surface, and the flash apparatus has a blocking member, which is configured to block flash light from the flash generator, which is directed towards the modelling light generator.

[0012] The inventors have surprisingly discovered that many common modelling light generators are sensitive to high power flash light. The inventors have realized that when using high power flash generators, modelling light generators such as, e.g., modelling light generators based on light emitting diodes might be damaged by the high power in the flash light.

[0013] By arranging the flash generator and the modelling light generator in the above described way, the beam lobes may be made to coincide to a large extent. Such an arrangement facilitates the design of a bracket to which the modelling light generator is attached.

[0014] By providing a blocking member, which is configured to block flash light from the flash generator, which is directed towards the modelling light generator, the above problem is eliminated. With such a blocking member, it is ensured that the surface of the modelling light generator is in shadow from the flash generator and is not exposed to direct flash light. In this way, the light protection of the modelling light generator is significantly enhanced.

[0015] The flash light may be emitted in a first beam lobe along a first direction, and the modelling light is emitted in a second beam lobe along a second direction, the angle between the first and second direction is less than 20 degrees, preferably less than 10 degrees, and most preferred less than 5 degrees. For the modelling light to be as useful as possible, the modelling light should be directed generally in the same direction as the flash light.

[0016] The first beam lobe may have a first beam angle, and the second beam lobe may have a second beam angle, which is 90-110% of the beam angle of the first beam lobe. For the modelling light to be as useful as possible, the modelling light should have a beam angle similar to the beam angle of the flash light.

[0017] The modelling light may be a continuous light, light intended for film, film light or the like. The modelling light may be a pulsed light. If the modelling light is pulsed at a sufficiently high frequency, the light is percepted as a continuous light. If the modelling light is pulsed, the frequency of the pulsing is higher than 25 Hz, preferably higher than 50 Hz and most preferred higher than 100 Hz. If the modelling light is pulsed and is intended for filming, the frequency of pulsed light is preferably at least 1000 Hz.

[0018] The modelling light generator may comprise at least one light emitting diode, LED. The modelling light generator may be a chip on board, COB, LED, comprising a plurality of LEDs covered by phosphors and polymers, such as silicone encapsulants. The inventors have surprisingly realized that the phosphors and polymers covering the LEDs is particularly sensitive to high intensity light from the flash generator. The phosphors are used to generate light in a broader wavelength range. The LEDs are preferably configured to generate short wavelength light such as light in the wavelength range of 400-450 nm. The phosphor will generate light with a longer wavelength. If the phosphor and polymers are damaged by high intensity light, the light emission from the phosphor will decrease. The modelling light generator may have a circular shape. This is a favourable shape to provide an even beam lobe from the modelling light generator.

[0019] The flash apparatus may comprise a reflector being arranged between the flash generator and the flash housing, and being configured to reflect and direct flash light from the flash generator, wherein the blocking member is attached to the reflector. With such a reflector, the light from the flash generator, which is directed towards the flash housing, will be re-directed away from the flash housing. This increases the amount of light from the flash generator that is emitted from the flash apparatus. Additionally, the heating of the flash housing and its internal components is minimized. The blocking member is preferably attached to the reflector. Preferably, the blocking member is a part of the reflector. By making the blocking member part of the reflector, the heating of the blocking member is minimized and the number of parts in the flash apparatus is minimized. The reflector and its integrated blocking member may be made in one piece.

[0020] The flash generator may be a Xenon flash tube. Furthermore, the flash generator may be a toroidal Xenon flash tube. Xenon flash tubes may provide a high intensity flash light. A toroidal Xenon flash tubes is a favourable shape to provide an even beam lobe from the flash generator.

[0021] The length axis may coincide with the length axis, wherein the toroidal Xenon flash tube is arranged symmetrically surrounding the length axis direction, and wherein the modelling light generator is centred on the length axis. By arranging the toroidal Xenon flash tube in this way the beam lobe will be centred on the length axis.

[0022] The flash housing may be circularly symmetrical around a symmetry axis, wherein the symmetry axis coincides with the length axis. This is a favourable shape of the flash housing.

[0023] A tube may be arranged surrounding the modelling light generator and extending along the length axis from the modelling light generator, wherein the inside of the tube is reflective. With such a tube, the modelling light generator may be arranged further away from the flash generator. Such an arrangement reduces the heat transfer from the flash generator to the modelling light generator.

[0024] In the following embodiments of the invention will be described with reference to the appended drawings.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 shows in cross section a front module of an off-camera flash apparatus for photographic purposes.

[0027] Figures 2 and 3 show perspective views of a front module of an off-camera flash apparatus for photographic purposes according to an alternative embodiment

[0028] Figure 4 shows in cross section the a front module of the off-camera flash apparatus according to Figures 2 and 3.

[0029] Figure 5 is a front view of the front module of the off-camera flash apparatus of Figures 2 and 3.

[0030] Figure 6 shows schematically an off-camera flash apparatus according to another embodiment.

[0031] Figure 7 shows schematically an off-camera flash apparatus according to another embodiment.

[0032] DETAILED DESCRIPTION

[0033] In the following description of embodiments, the same reference numeral will be used for similar features in the different drawings. The drawings are not drawn to scale.

[0034] Figure 1 shows in cross section a front module 1 of an off-camera flash apparatus for photographic purposes. The front module may be connected to, e.g., a battery to form the flash apparatus. The term off-camera flash is used for flash apparatuses that are configured to be used unattached to a camera. The front module 1 of the flash apparatus comprises a housing 2 with a length axis L, a flash generator 3 arranged at a first end of the housing 2 along the length axis L and configured to generate a flash light emitted from the flash apparatus. The front module 1 of the flash apparatus also comprises a modelling light generator 4 arranged at the first end of the housing 2 and configured to generate a modelling light emitted from the flash apparatus. The emission of light from the modelling light generator 4 is illustrated by first emission lines 5 for the light from the modelling light generator 4. The emission of light from modelling light generator 4 has its highest intensity in a direction along the length axis L. The first emission lines 5 depict the cone within which the intensity of the light from the modelling light generator 4 is at least 50% of the peak intensity from the modelling light generator 4. Modelling light may be used to illuminate a subject prior to using the flash generator 3. During illumination with the modelling light from the model light generator 4 it is possible to check how shadows will be when illuminating with the flash generator 3. This allows adjustment of the position of the modelling light generator 4 and the subjects before capturing an image of the subject using the flash generator 3. The modelling light may also be used during filming. The a front module 1 of the flash apparatus also comprises a blocking member 6, which is configured to block flash light from the flash generator 3, which is directed towards the modelling light generator 4.

[0035] In Figure 1, the flash generator 3 is a toroidal Xenon flash tube. The need for a blocking member 6 is largest when the flash generator emits light with a high intensity, such as gas discharge flash tubes. Xenon flash tubes is a common type of flash tube. The flash tube does not have to be toroidal. The light from the flash generator 3 is emitted from all around the flash generator 3. The light is only blocked in the direction towards the housing 2. The lines 7 shows the largest emission angle for the light from the flash generator 3. The front module 1 of the flash apparatus comprises power electronics 8 inside the housing 2. A reflector 9 is arranged between the flash generator 3 and the housing 2. The reflector 9 reflects light from the flash generator away from the housing 2. In this way, excessive heating of the flash housing is avoided. The blocking member 6 is a part of the reflector 9. The reflector 9 is arranged to reflect and direct flash light from the flash generator. The toroidal Xenon flash tube is arranged symmetrically surrounding the length axis L, and the modelling light generator 4 is centred on the length axis L.

[0036] The modelling light generator comprises at least one light emitting diode, LED. The modelling light generator may be a chip on board, COB, LED, comprising a plurality of LEDs covered by phosphors and polymers, such as silicone encapsulants.

[0037] Figures 2 and 3 show perspective views of a front module 1 of an off-camera flash apparatus for photographic purposes according to an alternative embodiment. Figure 4 shows in cross section the front module 1 of the off-camera flash apparatus. Figure 5 is a front view of the front module 1 of an off-camera flash apparatus of Figures 2 and

[0038] 3. In the embodiment shown in Figures 2-5, the front module of the flash apparatus comprises an outer wall 10. The outer wall 10 limits the emission angle of the light from the flash generator as is shown by the second emission lines 11 in Figure 4. The intensity of the flash light is uniform around the flash tube. The intensity of the flash light is the same between the second emission lines 11. The first emission lines 5 depict the cone within which the intensity of the light from the modelling light generator 4 is at least 50% of the peak intensity from the modelling light generator 4. The first emission lines 5 defines the beam angle of the modelling light. As can be seen in Figure 4 the emission angle of the flash light is larger than the beam angle of the modelling light. Both the flash light and the modelling light are emitted in essentially the same direction along the length axis L.

[0039] The toroidal Xenon flash tube defines a centre plane 12, which is perpendicular to the length axis L. The modelling light generator 4 comprises a plane light emitting surface 13 which is perpendicular to the length axis L, and wherein the centre plane 12 is downstream the modelling light generator 4 in the light emission direction of the light emitting surface 13. As can be seen in the embodiment of Figure 5, the modelling light generator 4 has a circular shape.

[0040] In the embodiment of Figures 2-5, the flash housing 2 is circularly symmetrical around a symmetry axis, wherein the symmetry axis coincides with the length axis L.

[0041] Figure 6 shows schematically a flash apparatus 18 with a front module 1 and a battery 19 according to another embodiment. The dashed line 20 illustrates the border between the battery 19 and the front module 1. The flash light is emitted in a first beam lobe 5 along a first direction 14, and the modelling light is emitted in a second beam lobe 11 along a second direction 15, the angle aa between the first direction 14 and the second direction 15 is less than 20 degrees, preferably less than 10 degrees, and most preferred less than 5 degrees. Also, the first beam lobe 11 has a first beam angle ai, and wherein the second beam lobe 5 has a second beam angle a?, which preferably is 90-110% of the beam angle of the first beam lobe.

[0042] The first beam lobe 5 has a first beam angle, and the second beam lobe 11 has a second beam angle, which may be essentially equal to the beam angle of the first beam Iobe5.

[0043] Figure 7 shows schematically an off-camera flash apparatus 18 according to another embodiment. The flash apparatus 18 comprises a tube 16 arranged surrounding the modelling light generator 4 and extending along the length axis L from the modelling light generator 4, wherein the inside of the tube 16 is reflective. The light from the modelling light generator 4 will be reflected inside the tube 16 and will exit the tube with essentially the same beam lobe as it would have been emitted directly from the modelling light generator.

[0044] The embodiments described above may be modified in many ways without departing from the scope of the invention, which is limited only by the appended claims.

Claims

CLAIMS1. An off-camera flash apparatus (18) for photographic purposes, said flash apparatus (18) comprising- a housing (2) with a length axis (L),- a toroidal Xenon flash tube (3) arranged at a first end (17) of the flash housing (2) along the length axis (L) and configured to generate a flash light emitted from the flash apparatus (18), and- a modelling light generator (4) arranged at the first end (17) of the flash housing (2) and configured to generate a modelling light emitted from the flash apparatus (18), characterized in that- the modelling light generator (4) comprises a plane light emitting surface (13) which is perpendicular to the length axis (L),- the toroidal Xenon flash tube defines a centre plane (12) which is perpendicular to the length axis (L), and which is downstream the light emitting surface (13) of the modelling light generator (4) in the light emission direction of the light emitting surface (13), and- the flash apparatus (18) has a blocking member (6) which is configured to block flash light from the flash generator (3), which is directed towards the modelling light generator (4).

2. The flash apparatus (18) according to claim 18, wherein the flash light is emitted in a first beam lobe (11) along a first direction (14), and the modelling light is emitted in a second beam lobe (5) along a second direction (15), wherein the angle between the first direction (14) and the second direction (15) is less than 20 degrees, preferably less than 10 degrees, and most preferred less than 5 degrees.

3. The flash apparatus (18) according to claim 1 or 2, wherein the first beam lobe (11) has a first beam angle (ai), and wherein the second beam lobe (5) has a second beam angle (a?) which is 90-110% of the beam angle (ai) of the first beam lobe (11).

4. The flash apparatus (18) according to anyone of claims 1, 2 or 3, wherein the modelling light generator (4) comprises at least one light emitting diode, LED.

5. The flash apparatus (18) according to claim 4, wherein the modelling light generator (4) is a chip on board, COB, LED, comprising a plurality of LEDs covered by phosphors and polymers, such as silicone encapsulants.

6. The flash apparatus (18) according to claim 4 or 5, wherein the modelling light generator (4) has a circular shape.

7. The flash apparatus (18) according to any one of the preceding claims, comprising a reflector (9) being arranged between the flash generator (3) and the flash housing (2), and being configured to reflect and direct flash light from the flash generator (3), wherein the blocking member (6) is attached to the reflector (9).

8. The flash apparatus (18) according to claim 7, wherein the blocking member (6) is a part of the reflector (9).

9. The flash apparatus (18) according to any one of the preceding claims, wherein the flash generator (3) is a Xenon flash tube10. The flash apparatus (18) according to claim 10, wherein the toroidal Xenon flash tube is arranged symmetrically surrounding the length axis direction (L), and wherein the modelling light generator (4) is centred on the length axis (L).

11. The flash apparatus (18) according to any one of the preceding claims, wherein the flash housing (2) is circularly symmetrical around a symmetry axis, wherein the symmetry axis coincides with the length axis (L).

12. The flash apparatus (18) according to any one of the preceding claims, wherein a tube (16) is arranged surrounding the modelling light generator (4) and extending along the length axis (L) from the modelling light generator (4), wherein the inside of the tube (16) is reflective.

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