GB2123539A

GB2123539A - Video recording light

Info

Publication number: GB2123539A
Application number: GB08219896A
Authority: GB
Inventors: Ashraff Allen Umer
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-07-09
Filing date: 1982-07-09
Publication date: 1984-02-01
Also published as: GB2123539B

Abstract

A portable video recording light (1) is made to be mounted on top of a video camera (2) to illuminate the subject being recorded. The light comprises a louvred casing (3) with a hinged top panel (4) giving access to a bulb. The casing is supported by a bracket (16) one end of which carries a clamping screw (19) for adjustably clamping the light on the video camera (2). The front of the casing has pivotable flaps (9) which direct the light towards the subject and reduce shadows. The light is powered from a portable battery pack through a flexible cable (22). <IMAGE>

Description

SPECIFICATION Video recording light Field of Invention This invention relates to a light for use in video recording.

Background to the Invention When making a video film indoors it is necessary to provide adequate lighting for the subject being recorded. Hitherto, lights for this purpose have been bulky and unsuitable to be carried around to follow a moving subject.

An object of the invention is to provide a video recording light which is light in weight, is suitable to be attached to a video camera and which can be powered from a portable battery source.

Summary of the Invention According to the invention a light for use in video recording comprises a casing having a bulb holder and being made of a lightweight heat conducting material shaped to facilitate dispersion to the surrounding air of heat generated by the bulb, and mounting means for mounting the light on a support such as a video camera or a tripod.

The casing is preferably of an aluminium alloy and may be formed with louvres to enable a cooling air flow to pass through the casing. The casing may be generally box-shaped having an open front end through which light from the bulb can pass. As a further aid to dissipating heat generated by the bulb, the casing may have a further heat dissipating member which is conveniently also louvred and spaced from adjacent panels of the casing to provide airflow passages. The casing and the additional heat dissipating member are preferably finished in black so that as much heat as possible is lost in radiation.

The mounting means may be in the form of a bracket which is adjustable both angularly and longitudinally with respect to the casing, clamping means being provided to clamp the casing in an adjusted position with respect to the bracket. The end of the bracket remote from the casing preferably carries means which enable the light to be mounted on a video camera, on a tripod or on any other support surface. In the embodiment to be described the bracket can be clamped onto a camera mount which can be located and clamped in position on the top of a video camera.

The casing may have means which direct the light towards the subject being recorded, these means conveniently being pivotable flaps pivotally mounted on the open end of the casing. When adjusted to a desired pivotal position, the flaps cooperate to act in the manner of a shade to direct the light towards the object being viewed thereby minimising shadows. The flaps are conveniently made so that they can be pivoted to a closed position in which they cover the open end of the casing and protect the front of the light.

Power for the light is preferably supplied by means of a flexible lead, one end of which passes through the casing and is attached to the bulb holder and the other end of which terminates in a plug for insertion into a socket providing electrical power, preferably from a low voltage portable source such as the 12 volt DC portable power pack disclosed in the Applicant's co-pending British Patent Application No. 8208681.

The invention includes within its scope the combination of the inventive video light and a video camera, with or without a portable battery pack.

A video recording light according to the invention can be made extremely light in weight, for example less than 1 Ib with a bulk operating at 13.8 volts DC and with an 85 watt output. This light weight enables the video recording light to be mounted on a video camera for hand operation or to be hand-held separately. In either case, the video recording light can be moved around to follow a moving subject and does not need the provision of a mains power source but can be powered from a portable battery pack, making the user independent and able to move around without being encumbered by wires or cables.

A video recording light according to the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view showing the video recording light mounted on top of a video camera; Figure 2 is a perspective view of the video recording light alone; Figure 3 is a perspective view showing the parts of the video recording light in 'exploded' view; and Figure 4 shows the video recording light in a form suitable to be hand-held.

Detailed Description of the Drawings Figure 1 shows the video recording light 1 mounted on top of a video camera 2. As best shown in Figures 2 and 3, the video recording light has a box-like casing 3 which is made of aluminium alloy and which has a hinged top panel 4 to enable access to be gained for insertion or removal of a bulb 5 in a bulb-holder (not shown) secured in the casing 3. The casing 3 has an open front end 6, and all the panels except for the back panel have louvres 7 to promote a convection airflow through the casing to aid cooling thereof.

To the front of the casing 3 is fitted a frame 8 carrying four pivotally mounted flaps or so-called 'barn doors' 9. The drawings show the barn doors in their open position. The barn doors 9 may be pivotally adjusted to direct the light from the bulb 5 in a desired direction, thereby avoiding unwanted spread of the light beam and shadowing of the subject being recorded. When the video recording light is not in use the barn doors 9 may be pivoted to a closed position in which they cover and protect the front of the light.

An additional heat dissipating member 10 can be positioned and clamped onto the casing 3 to assist heat dissipation from the casing 3. As best shown in Figure 3, the member 10 has the shape of an inverted channel with inturned lips 1 2 which ensure the maintenance of an airgap between the member 10 and the side and top panels of the casing 3. The member 10 is secured in position by a clamping arrangement comprising a threaded stud 1 3 projecting from one side of the casing 3 and a clamping nut 14 which is threaded onto the stud 13. One side flange of the member 10 has an elongated slot 15 which enables the member 10 to be slid over the stud 1 3 and secured in position by tightening of the clamping nut 14. The member 10 has louvres 11.

The threaded stud 13 and the clamping nut 14 also act to retain one end of a bracket 16 on the side of the light casing 3. The bracket 16 is generally L-shaped, each limb having an elongated slot 17 or 18. The slot 17 enables the bracket 16 to be slid along the stud 13 and clamped onto the casing 3 at a desired angular and longitudinal position with respect to the casing 3.

The slot 1 8 is intended to receive the threaded shank of a clamping screw 1 9 which is threaded into a camera mount 20 shaped to be receivable in a shoe mounted on the top of the camera 2.

Tightening of the screw 1 9 therefore clamps the video light 1 on top of the camera 2. The clamping screw 1 9 and the clamping nut 14 can be slackened and then re-tightened to adjust the position of the video light 1 on the camera 2.

Electrical powerforthe bulb 5 is conducted through a flexible lead 22 having at its end remote from the casing 3 a plug which fits into a socket (preferably similar to a cigar lighter socket on a motor vehicle) on a portable battery pack. The plug is indicated at 23 in Figure 4 which shows the video recording light fitted with a straight handle 24 enabling the video recording light to be hand-held. In other respects the light shown in Figure 4 is similar to that of Figures 1 to 3.

The bulb 5 is a quartz multi-mirrored reflecting type having an operating voltage of 13.8 and an output of 85 watts. The casing 3 and heat dissipating member 10 enable the light to be powered for fairly long periods (e.g. up to 75 minutes) without the casing 3 becoming unacceptably hot. The casing 3, the frame 8, the barn doors 9 and the heat dissipating member 10 have a black finish so that they act as efficient black-body radiators of heat, this radiation supplementing the convection cooling which occurs as a result of airflow through the space between the casing 3 and the heat dissipating member 10 and through the louvres of the casing 3 and the heat dissipating member 10.

It will be appreciated that the bulb 5 may be of any convenient voltage, power and shape. The preferred bulb gives a shadow free light for a distance of at least six feet from the light, with wide angle deflection beam.

Claims

1. A light for use in video recording, comprising a casing having a bulb holder and being made of a lightweight heat conducting material shaped to facilitate dispersion to the surrounding air of heat generated by the bulb, and mounting means for mounting the light on a support such as a video camera or a tripod, wherein the casing has means which direct the light towards the subject being recorded.

2. A light according to claim 1, wherein the casing is of aluminium alloy and is formed with louvres to enable a cooling airflow to pass through the casing.

3. A light according to claim 3, wherein the casing is generally box-shaped, having an open front end through which light from the bulb can pass.

4. A light according to claim 3, wherein the casing has a further heat dissipating member which is also louvred and spaced from adjacent panels of the casing to provide airflow passages.

5. A light according to claim 4, wherein the casing and the additional heat dissipating member are finished in black so that as much heat as possible is lost in radiation.

6. A light according to any of the preceding claims, wherein the mounting means are in the form of a bracket which is adjustable both angularly and iongitudinally with respect to the casing, clamping means being provided to clamp the casing in an adjusted position with respect to the bracket.

7. A light according to any of the preceding claims, wherein the means which direct the light are pivotable flaps pivotally mounted on the open end of the casing.

8. A light according to claim 7, wherein the flaps are made so that they can be pivoted to a closed position in which they cover the open end of the casing and protect the front of the light.

9. A light according to any of the preceding claims, wherein power for the light is supplied by means of a flexible lead, one end of which passes through the casing and is attached to the bulb holder and the other end of which terminates in a plug for insertion into a socket providing electrical power, e.g. from a low voltage portable source such as the 12 volt DC portable power pack.

10. A light constructed and arranged substantially as herein particularly described with reference to the accompanying drawings.

11. A light according to any of the preceding claims and in combination with a video camera.