Patent GB-1432253-A (GB)
Title: Camera for use with still or cinematorgraphic films
IPC: G03B17/16
Filed: 1973-06-06
Abstract: 1432253 Cameras with two films K VOCKENHUBER AND R HAUSER 6 June 1973 [6 June 1972 (2) 4 July 1972 12 July 1972] 26915/73 Headings G2A and G2E A camera selectively operable for still and cine pictures on separate films has a lens system common to both films, deflector means displaceable to pass light to one film or the other, and either a common shutter for both films, or two separate shutters so arranged that neither can be operated when the deflector means is in the inappropriate position. Light from a scene passes through lenses 4 and 5 Fig. 1A and onto a mirror 7 having a zone 8 of total reflectivity, a zone 9 of 50% reflectivity and a zone 10 which is wholly transparent. The light therefore is either (a) totally reflected by zone 8 through an objective 11 on to a mirror 12 which deflects the light through a shutter 13 to the imaging window of a still film cassette 3, (b) passes through the transparent section 10, through a rotating shutter 6 to the imaging window of a cine film cassette 2 or (c) reaches the films in both cassettes when the partly transparent zone 9 is in the light path. In an alternative embodiment Fig. 1B (not shown) the mirror 7 is omitted and the shutter (6a) has a mirrored surface and is inclined to the light path so that as the shutter rotates the light alternately passes to the cine film cassette or is reflected to the still film cassette, the shutter 13  being controlled so that it only operates when the shutter (6a) is deflecting the light to the still imaging window. Two release buttons 14, 15 are provided for actuating shutters 6 and 13. A locking mechanism is set so that only a selected one, or both of the buttons may be depressed, the mechanism also setting the position of the zoned mirror 7. In a third embodiment mirror 7 is replaced by a hinged mirror (28) Fig. 2 which is introduced into or removed from the light path to deflect the light to the still imaging window. This arrangement does not permit simultaneous exposure of both films thus the locking mechanism, which sets the mirror position and also adjusts the front objective (lenses 4 and 5) only allows one of the two buttons to be released. Alternatively a single switch may be depressed Fig. 15 and close contacts which have previously been set to actuate either or both shutters, the setting also positioning the mirror. Shutters Various forms of shutter are disclosed. One comprises two rotatable sectors which are adjusted to vary the aperture between them, the aperture determining the exposure time for both the cine and the still film. In an alternative embodiment one of the sectors is silvered and reflects light to the still film, thus the extent to which the silvered sector is covered by the other sector determines the exposure time for the still film while the aperture between the sectors determines the cine film exposure time. Other arrangements in which both sectors are silvered, or in which a series of blades may be drawn over a single silvered shutter sector are also disclosed. Flash-bulb exposure The cine film and still film are usually responsive to artificial light and daylight respectively, therefore for daylight filming a filter is provided in the light path to the cine film . If a flash-bulb is inserted in the camera the filter is automatically moved out of the light path and a slide moved to prevent release of the still film shutter. Actuating of either the still or the cine film shutter may also be prevented in response to meters which measure the colour temperature of the ambient light. Diaphragm setting A mechanism for setting both diaphragms by a single drive motor is disclosed, Fig. 12. Sensors 144, 145 sense the cine and still film sensitivity by engaging cooling recesses 142, 143 provided on cassettes 2 and 3 respectively. This information is transmitted to differential gearing 146. The sensitivity of the still film is also transmitted to a diaphragm control 151, the control also receiving information concerning the ambient light level to set, via a motor 152, the still film diaphragm 140. The output of control 151 and the output of differential gearing 146 are fed to a further differential gearing 154. The output of gearing 154 contains only the information regarding the sensitivity of the cine film and the ambient light and sets cine film diaphragm 141 in response thereto, thus both diaphragms are set by the single motor 152. In an alternative embodiment a single diaphragm e.g. located between lenses 4 and 5, is set in response to the ambient light and to the sensitivity of whichever film is to be exposed.