Camera with means for indicating automatically determined exposure times

Claim 2

In a photographic camera, a combination comprising shutter means movable between open and closed positions to provide a range of exposure times; release means operative to effect opening of said shutter means; an electric delay circuit for effecting closing of said shutter means following the operation of said release means and with a delay which is a function of the intensity of scene light; and indicating means including an electric testing circuit having signal-generating means for producing signals indicating the actual length of exposure time as a function of the intensity of scene light at least in a portion of said range and at least during the interval preceding an exposure.

Claim 3

A combination as defined in claim 1, said signal-generating means comprises means for producing signals whose frequency varies as a function of the intensity of scene light.

Claim 4

A combination as defined in claim 1, wherein said signal-generating means comprises means for producing signals whose duration varies as a function of the intensity of scene light.

Claim 5

A combination as defined in claim 1, wherein said signal-generating means comprises means for producing signals whose frequency and duration vary as a function of the intensity of scene light.

Claim 6

A combination as defined in claim 1, wherein said indicating means further comprises actuating means for energizing said testing circuit while the shutter means is closed.

Claim 7

A combination as defined in claim 5, wherein said actuating means constitutes said release means.

Claim 8

A combination as defined in claim 1, wherein said testing circuit is integrated into said delay circuit.

Claim 9

A combination as defined in claim 1, wherein said testing circuit further comprises proportioning means for determining the length of said signals so that such length is proportional to appropriate exposure time for a particular scene brightness.

Claim 10

A combination as defined in claim 8, wherein said proportioning means comprises means for effecting generation of signals which are shorter than the corresponding exposure times.

Claim 11

A combination as defined in claim 8, wherein said proportioning means comprises means for effecting generation of signals which are longer than the corresponding exposure times.

Claim 12

A combination as defined in claim 8, wherein said testing circuit comprises exposure time determining first capacitor means and said proportioning means comprises at least one second capaCitor means whose capacitance is different from that of said first capacitor means, and selector means for substituting said second capacitor means for said first capacitor means.

Claim 13

A combination as defined in claim 1, wherein said signal-generating means comprises means for producing audible signals.

Claim 14

A combination as defined in claim 1, wherein said indicating means comprises control means for effecting generation of a sequence of recurring signals.

Claim 15

A combination as defined in claim 13, wherein said control means is arranged to effect generation of signals at a frequency which varies as a function of the intensity of scene light.

Claim 16

A combination as defined in claim 13, wherein said control means is arranged to effect generation of signals whose duration varies as a function of the intensity of scene light.

Claim 17

In a photographic camera, a combination comprising shutter means movable between open and closed positions to provide a range of exposure times; release means operative to effect opening of said shutter means; an electric delay circuit for effecting closing of said shutter means with a variable delay following operation of said release means, said delay circuit comprising light-sensitive receiver means, exposure time determining capacitor means which is charged through said receiver means, a flip-flop which detects the charge of said capacitor means, and electromagnet means which effects closing of said shutter means in response to interruption of current supply thereto by said flip-flop when the charge of said capacitor means rises to a predetermined value; and indicating means including an electric testing circuit integrated into said delay circuit and having signal-generating means for producing signals indicating the length of exposure time at least in a portion of said range as a function of the intensity of scene light, said testing circuit further having master switch means for connecting said signal-generating means into said delay circuit in lieu of said electromagnet means so that said signal-generating means produces signals of a duration corresponding to the interval during which said electromagnet means is energized at a given light intensity, said release means being movable from a starting position in a first direction to open said shutter means and to complete said delay circuit with resulting energization of said electromagnet means for an interval of time which is a function of the intensity of scene light detected by said receiver means, and in a second direction to complete said testing circuit and to connect said signal-generating means in said delay circuit in lieu of said electromagnet means so that said signal-generating means produces a signal whose duration is a function of said intensity as detected by said receiver means.

Claim 18

In a photographic camera, a combination comprising shutter means movable between open and closed positions to provide a range of exposure times; release means operative to effect opening of said shutter means; an electric delay circuit for effecting closing of said shutter means with a variable delay following operation of said release means, said delay circuit comprising light-sensitive receiver means, exposure time determining capacitor means which is charged through said receiver means, a flip-flop which detects the charge of said capacitor means, and electromagnet means which effects closing of said shutter means in response to interruption of current supply thereto by said flip-flop when the charge of said capacitor means rises to a predetermined value; and indicating means including an electric testing circuit integrated into said delay circuit and having signal-generating means for producing signals indicating the length of exposure time at least in a portion of said range as a function of the intensity of scene light, said testing circuit further having master switch means for connecting said signal-generating means into said delay circuit in lieu of said electromagnet means so that said signal-generating means produces signals of a duration corresponding to the interval during which said electromagnet means is energized at a given light intensity, said release means being movable from a starting position in a first direction to open said shutter means and to complete said delay circuit with resulting energization of said electromagnet means for an interval of time which is a function of the intensity of scene light detected by said receiver means, and in a second direction to complete said testing circuit and to connect said signal-generating means in said delay circuit in lieu of said electromagnet means so that said signal-generating means produces a signal whose duration is a function of said intensity as detected by said receiver means.

Claim 19

A combination as defined in claim 16, further comprising housing means supporting said release means, and guide means provided on said housing means to prevent movement of said release means in said second direction after said release means leaves said starting position in said first direction, and vice versa.

Claim 20

In a photographic camera, a combination comprising shutter means movable between open and closed positions to provide a range of exposure times; release means operative to effect opening of said shutter means; an electric delay circuit for effecting closing of said shutter means with a variable delay following the operation of said release means; and indicating means including an electric testing circuit having signal-generating means for producing signals indicating the length of exposure time at least in a portion of said range as a function of the intensity of scene light, said testing circuit further having auxiliary elements connected in parallel and/or series with said signal-generating means to suppress the signal at a predetermined range of light intensities.

Claim 21

In a photographic camera, a combination comprising shutter means movable between open and closed positions to provide a range of exposure times; release means operative to effect opening of said shutter means; an electric delay circuit for effecting closing of said shutter means with a variable delay following the operation of said release means; and indicating means including an electric testing circuit having signal-generating means for producing signals indicating the length of exposure time at least in a portion of said range as a function of the intensity of scene light, said testing circuit further having auxiliary elements connected in parallel and/or series with said signal-generating means to suppress the signal at a predetermined range of light intensities.

Claim 22

In a photographic camera, a combination comprising shutter meaNs movable between open and closed positions to provide a range of exposure times; release means operative to effect opening of said shutter means; an electric delay circuit for effecting closing of said shutter means with a variable delay following the operation of said release means; and indicating means including an electric testing circuit having signal-generating means for producing signals indicating the length of exposure time at least in a portion of said range as a function of the intensity of scene light, said testing circuit further having exposure time determining first capacitor means and proportioning means for determining the length of said signals so that such length is proportional to appropriate exposure time for a particular scene brightness, said proportioning means comprising a plurality of second capacitor means whose capacitance is different from that of said first capacitor means, selector means for substituting a selected one of said second capacitor means for said first capacitor means, said selector means being movable to and from an idle position in which said first capacitor means is connected in said testing circuit, and resetting means for moving said selector means to idle position in response to operation of said release means.

Claim 23

In a photographic camera, a combination comprising shutter meaNs movable between open and closed positions to provide a range of exposure times; release means operative to effect opening of said shutter means; an electric delay circuit for effecting closing of said shutter means with a variable delay following the operation of said release means; and indicating means including an electric testing circuit having signal-generating means for producing signals indicating the length of exposure time at least in a portion of said range as a function of the intensity of scene light, said testing circuit further having exposure time determining first capacitor means and proportioning means for determining the length of said signals so that such length is proportional to appropriate exposure time for a particular scene brightness, said proportioning means comprising a plurality of second capacitor means whose capacitance is different from that of said first capacitor means, selector means for substituting a selected one of said second capacitor means for said first capacitor means, said selector means being movable to and from an idle position in which said first capacitor means is connected in said testing circuit, and resetting means for moving said selector means to idle position in response to operation of said release means.

Claim 24

In a photographic camera, a combination comprising shutter means movable between open and closed positions to provide a range of exposure times; release means operative to effect opening of said shutter means; an electric delay circuit for effecting closing of said shutter means with a variable delay following the operation of said release means; and indicating means including an electric testing circuit having signal-generating means for producing signals indicating the length of exposure time at least in a portion of said range as a function of the intensity of scene light and control means for effecting the generation of a sequence of recurring signals, said signal-generating means comprising a lamp and said control means comprising a light-sensitive receiver exposed to scene light and means for directing light emitted by said lamp against said receiver.

Claim 25

In a photographic camera, a combination comprising shutter means movable between open and closed positions to provide a range of exposure times; release means operative to effect opening of said shutter means; an electric delay circuit for effecting closing of said shutter means with a variable delay following the operation of said release means; and indicating means including an electric testing circuit having signal-generating means for producing signals indicating the length of exposure time at least in a portion of said range as a function of the intensity of scene light and control means for effecting the generation of a sequence of recurring signals, said signal-generating means comprising a lamp and said control means comprising a light-sensitive receiver exposed to scene light and means for directing light emitted by said lamp against said receiver.

Claim 26

In a camera, automatic exposure time determining means, photosensitive resistor means for receiving light the intensity of which corresponds to the intensity of light of an object which is to be photographed, exposure time circuit means operatively connected between said photosensitive resistor means and said exposure time determining means for actuating the latter in accordance with the intensity of light received by said photosensitive resistor means, a signal lamp, signal circuit means including a plurality of transistors and operatively connected between said photosensitive resistor means and said signal lamp for energizing the latter when the light received by said photosensitive resistor means is within a given range of light intensity at intervals determined by the intensity of light within said range so as to provide at said lamp a blinking signal the frequency of which is indicative of the light intensity and thus indicative of the exposure time, and means coacting with said signal circuit means to provide through said signal circuit means at said lamp a blinking frequency determined by the light intensity within said range and an additional factor, said photosensitive resistor means including only a single photosensitive resistor which coacts both with said signal circuit means in the control of said signal lamp and with said exposure time circuit means in the control of said automatic exposure time determining means.

Claim 27

In a camera, automatic exposure time determining means, photosensitive resistor means for receiving light the intensity of which corresponds to the intensity of light of an object which is to be photographed, exposure time circuit means operatively connected between said photosensitive resistor means and said exposure time determining means for actuating the latter in accordance with the intensity of light received by said photosensitive resistor means, a signal lamp, signal circuit means including a plurality of transistors and operatively connected between said photosensitive resistor means and said signal lamp for energizing the latter when the light received by said photosensitive resistor means is within a given range of light intensity at intervals determined by the intensity of light within said range so as to provide at said lamp a blinking signal the frequency of which is indicative of the light intensity and thus indicative of the exposure time, and means coacting with said signal circuit means to provide through said signal circuit means at said lamp a blinking frequency determined by the light intensity within said range and an additional factor, said photosensitive resistor means including only a single photosensitive resistor which coacts both with said signal circuit means in the control of said signal lamp and with said exposure time circuit means in the control of said automatic exposure time determining means.

Claim 28

The combination of claim 21 and wherein said signal circuit means coacts with said lamp for illuminating the latter at intervals providing a relatively low blinking frequency at relatively long exposure times and a relatively high blinking frequency at relatively short exposure times.