Source: http://www.google.com/patents/US4460263?dq=5754119
Timestamp: 2015-09-04 08:09:55
Document Index: 196307366

Matched Legal Cases: ['art 60', 'art 60', 'art 90', 'art 60', 'art 60', 'art 60', 'art 60']

Patent US4460263 - Apparatus for calculating and displaying and/or controlling exposure ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA camera control device (21) with means for electrically controlling the shutter of a camera and for setting and displaying exposure time and aperture is electrically connected to an electronic exposure computer (22). The latter contains electronic circuitries for the logic operation of exposure parameters...http://www.google.com/patents/US4460263?utm_source=gb-gplus-sharePatent US4460263 - Apparatus for calculating and displaying and/or controlling exposure parameters for photographic picturesAdvanced Patent SearchPublication numberUS4460263 APublication typeGrantApplication numberUS 06/377,209PCT numberPCT/CH1981/000100Publication dateJul 17, 1984Filing dateSep 8, 1981Priority dateSep 11, 1980Fee statusPaidAlso published asDE3152272C1, DE3152272D2, WO1982001080A1Publication number06377209, 377209, PCT/1981/100, PCT/CH/1981/000100, PCT/CH/1981/00100, PCT/CH/81/000100, PCT/CH/81/00100, PCT/CH1981/000100, PCT/CH1981/00100, PCT/CH1981000100, PCT/CH198100100, PCT/CH81/000100, PCT/CH81/00100, PCT/CH81000100, PCT/CH8100100, US 4460263 A, US 4460263A, US-A-4460263, US4460263 A, US4460263AInventorsKarl Gfeller, Carl Koch, Hans C. KochOriginal AssigneeSinar Ag SchaffhausenExport CitationBiBTeX, EndNote, RefManPatent Citations (5), Referenced by (10), Classifications (11), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetApparatus for calculating and displaying and/or controlling exposure parameters for photographic pictures
US 4460263 AAbstract
A camera control device (21) with means for electrically controlling the shutter of a camera and for setting and displaying exposure time and aperture is electrically connected to an electronic exposure computer (22). The latter contains electronic circuitries for the logic operation of exposure parameters which shall be input and output in the form of coded digital signals. In a preferred embodiment, the relative aperture selected for each situation is read into the exposure computer (22) by means of a coder placed in the camera control device (21). The corresponding exposure time is calculated by the exposure computer (22) on the basis of the aperture and other exposure parameters and set automatically at the shutter. The exposure parameter reproducing the brightness of a subject to be photographed can be read into the exposure computer (22) either manually or, by connecting a photoelectric brightness sensor (23), automatically. A flash unit (24) can be connected to the exposure computer (22), the flash output of the flash unit (24) can be controlled by output signals of the exposure computer. As a result of a single test flash the number of flashes that may be necessary is calculated and displayed by means of the exposure computer (22).
1. An apparatus for calculating and displaying the values of exposure parameters for photographic pictures, having electronic circuitries for the logic operation of the exposure parameter values which determine the exposure and which, in the form of electrical digitally coded signals, are input and output at signal inputs or signal outputs of the combinatorial logic circuitries, and having at least one display device, wherein a manually operated selector (83, 291) is assigned to the combinatorial logic circuitries (130, 230) for the selective programming of the combinatorial logic circuitries for the input and processing of measured values resulting from brightness measurements for continuous light or from exposure measurements for flashlight, wherein during the setting of the selector (83, 291) for exposure measurements for flashlight the combinatorial logic circuitries (130, 230) are programmed in such fashion that by means of a measured value obtained for a single test flash illumination they calculate the difference between the same and a nominal exposure value, including algebraic sign, and thereafter, by means of at least one digital display device (97, 98) indicate the same as a request for making a corresponding correction of at least one of the read-in exposure parameter values or of the flash illumination, and wherein the combinatorial logic circuitries (130, 230) are programmable in such fashion that in the presence of too low a measured value obtained for the test flash illumination the combinatorial logic circuitries (130, 230) calculate the number of successive equal flashes required for achieving the nominal exposure, and any residual difference in relation to the nominal exposure, and display the same by means of the display device (97, 98).
2. The apparatus as set forth in claim 1, wherein the combinatorial logic circuitries (130, 230) are programmable selectively for the calculation of at least one required exposure parameter value resulting from a single measured brightness or exposure value or by means of two or more consecutively read-in measured brightness or exposure values, and wherein in case of two or more measured values the latter are automatically stored after they have been read in, and the mean value is produced from the stored measured values and thereafter is utilized for calculating the required exposure parameter value.
3. The apparatus as set forth in claim 1, wherein by means of the selector (83, 291) the combinatorial logic circuitries (130, 230) are further programmable for performing exposure measurements with mixed light which is composed of flashlight as well as continuous light, signal inputs and signal outputs of the combinatorial logic circuitries (130, 230) being connected with a brightness sensor (23) which has a photoelectric converter (350), an analog to frequency converter (356), an integrator/storage unit (352) controlled by a gate time signal, and a changeover device (354, 355), by means of which the integrator/storage unit (352) can be switched off for brightness measurements with flashlight, the gate time of the integrator/storage unit (352) being controlled by the combinatorial logic circuitries (130, 230), and the changeover means (354, 355) being controlled by a signal from a signal output of the combinatorial logic circuitries (130, 230) as a function of the program set by means of the selector (83, 291), and wherein during the setting of the selector (83, 291) for exposure measurements for mixed light the combinatorial logic circuitries (130,230) are programmed in such fashion that they automatically and consecutively trigger an exposure measurement for test flash illumination and a brightness measurement for continuous-light illumination, so that there is read consecutively into the combinatorial logic circuitries a measured value resulting from an exposure measurement for the single test flash illumination, possibly with a continuous-light component, and a measured value resulting from the brightness measurement for continuous-light illumination, whereupon the two measured values are automatically processed with each other and with the other read-in exposure parameter values to calculate at least one required exposure parameter value.
4. The apparatus as set forth in claim 2, characterized in that the combinatorial logic circuitries (130, 230) control the display device (73) in such fashion that the latter indicates temporarily in each situation the last-input measured brightness or exposure value.
5. The apparatus as set forth in claim 2, characterized in that a signal input of the combinatorial logic circuitries (130, 230) is connected to a manually operated electric contact (102, 293), through the actuation of which the combinatorial logic circuitries can be programmed in such fashion that they compute the difference between the highest and the lowest valued brightness or exposure value stored and display the same by means of the display device (73).
6. The apparatus as set forth in claim 1, characterized in that at signal inputs and signal outputs of the combinatorial logic circuitries (130, 230) there is connected a brightness sensor (23) which has a photoelectric converter (350), an analog frequency converter (356), an integrator/storage unit (352) controlled by a gate time signal, and a changeover device (354, 355), by means of which the integrator/storage unit (352) can be switched off for brightness measurements with continuous light and switched on for exposure measurements with flashlight, that for exposure measurements with flashlight the gate time of the integrator/storage unit (352) is controlled by the combinatorial logic circuitries (130, 230) in conformity with the exposure time read-in by means of a coder (196), and that the changeover means (354, 355) is controlled by a signal from a signal output of the combinatorial logic circuitries (130, 230) as a function of the program set by means of the selector (83, 291).
7. The apparatus as set forth in claim 3, characterized in that the combinatorial logic circuitries (130, 230) can be programmed for the calculation of at least one required exposure parameter value on the basis of the mean value of two exposure values which are each obtained, and stored into memory, from a measured value resulting from an exposure measurement for test flash illumination and from a mesured value resulting from a brightness measurement for test flash illumination.
8. The apparatus as set forth in claim 3, characterized in that upon completion of at least one exposure measurement for mixed light the selector (83, 291) can be switched to a position in which the combinatorial logic circuits (130, 230) are programmed for performing any number of additional exposure measurements for test flash illumination and continuous-light illumination, through which additional measurements the result of the completed exposure measurement stored into memory is not affected, and that a manually operated electric contact (103, 294) is assigned to the combinatorial logic circuitries (130, 230), through the actuation of which the measured value resulting from the immediately preceding additional exposure measurements or its difference in relation to a nominal value is indicated for informational purposes in a display device (73).
9. The apparatus as set forth in claims 1, 2, or 3, characterized in that at least one light-controlling means (24) for controlling the light output of artificial flashlight or continuous-light sources is detachably connected to the combinatorial logic circuits (130, 230) and contains control electronics (385) with signal inputs and which, in turn, are designed to control the light sources, such that the light output of the light sources is varied automatically in accordance with the difference calculated by the combinatorial logic circuitries between an exposure value obtained from at least one brightness or exposure measurement and a nominal exposure value.
10. The apparatus as set forth in claim 9, characterized in that the light output can be varied by the light-controlling means (24) in identical intervals as the other exposure parameters, preferably in 1/3 exposure steps.
11. The apparatus as set forth in claim 9, characterized in that the control electronics (385) of the light-controlling means (24) has signal outputs which are connected to corresponding signal inputs of the combinatorial logic circuitries (130, 230) and read into the combinatorial logic circuitries by means of coded digital signals the extent of the available range of light output adjustment.
12. The apparatus as set forth in claim 11, characterized in that a data input device (398) is assigned to the control electronics (385) of the light-controlling means (24), said data input device (398) being utilized for the manual input of signals to vary the range of adjustment for the automatic light-output control.
13. The apparatus as set forth in claim 12, characterized in that the range of adjustment can be varied in equal intervals as the light output itself.
14. The apparatus as set forth in claim 11, characterized in that a plurality of light-controlling means (24-A through 24-D) for controlling the light output of flashlight or continuous-light sources are connected to the combinatorial logic circuitries (130, 230) via a unit (400, 405) which selects the signals delivered by the control outputs of the control electronics (385) of all the light-controlling means and transmits to the combinatorial logic circuitries only the signals that indicate the smallest range of light-output adjustment.
The present invention relates to an apparatus for calculating and displaying and/or controlling the values of exposure parameters and particularly the values of exposure time and aperture, in order to take properly exposed photographs, taking into account the data which are characteristic of the particular photographic picture material.
In contrast to device of known construction of this type, the apparatus embodying the principles of the invention is intended to be more universal in use and to permit either a manual or an automatic input of the film data and/or other exposure parameter values. Moreover, the apparatus is intended to continually take account of changes in the data that have been read in, regardless of the time and sequence of such changes. The invention is further designed to determine, as a result of a single test flash measurement, the number of flashes needed for the exact exposure of a shooting and/or to adapt the flash output of at least one flash unit automatically to the other exposure parameter values. Finally, the apparatus of the invention is capable of determining the exposure time needed for an exact exposure at a selected relative aperture even if the light is mixed, that is, if the subject is illuminated with flashlight and with continuous light.
Other objects and advantages, as well as the characteristic features of the invention, will be better understood from the following description taken in connection with the accompanying drawings in which a preferred embodiment and some variations of the subject of the invention have been set forth for purposes of illustration. In the drawings:
FIG. 1 is a schematic representation of an apparatus according to the invention and consisting of several modular units;
FIG. 2 is a rear view of a previously known part of a universal box camera, the front part containing one of the modular units of the apparatus in FIG. 1, carrying a lens provided with an iris stop, and having a camera shutter, a device for setting the iris stop of the lens, as well as display devices for indicating exposure times and stop settings;
FIG. 3 is a view of an exposure-computer module containing another modular unit of the apparatus of FIG. 1;
FIG. 4 is a block diagram of the electrical circuitry contained in the camera front part of FIG. 2;
FIGS. 5-7 show the details of the electrical circuitries of the various blocks in FIG. 4;
FIG. 8 is a block diagram of the electrical circuitry contained of the exposure-computer module in FIG. 3;
FIGS. 9-11 show the details of the electrical circuitries of the various blocks in FIG. 8;
FIG. 12 shows the electrical circuitry of a photoelectric brightness sensor, which is one of the modular units of the apparatus of FIG. 1;
FIG. 13 shows the electrical circuitry of an electronic flash gun with controlled flash output and constituting one of the modular units of the apparatus of FIG. 1;
FIG. 14 is a schematic representation of a variation of the apparatus of the invention having a plurality of controlled flash guns;
FIG. 15 is a time/brightness diagram explaining the operation of the apparatus for single-point brightness measurements of a subject illuminated both with flash and with continuous light;
FIG. 16 shows two associated time/illumination diagrams explaining the operation of the apparatus for two-point brightness measurements of a subject illuminated both with flash and with continuous light;
FIG. 17 is a photographic exposure/optical density diagram explaining the operation of the apparatus for brightness measurements.
The apparatus shown schematically in FIG. 1 for controlling the exposure of a photographic universal box camera comprises various modular units, namely a camera control unit 21, an exposure computer 22, a photoelectric brightness sensor 23, an electronic flash unit 24 with automatically controlled flash output, a film cassette holder 25, a film cassette 26, a shutter release and automatic cassette controlled shutter closing and reopening control device 27, and a power pack 28 serving as a current source for the electric supply of the whole apparatus. The camera control unit 21 and the exposure computer 22 each have a multipole connector 31 and 32, respectively, which are detachably connected by a multiwire electrical connecting cable for the electrical data transmission in either direction and for supplying electrical power. Advantageously, both connectors 31 and 32 are so constructed that they can also be plugged together directly, so that connecting cable 33 may be dispensed with.
Exposure computer 22 is further provided with three multipole connectors 34, 35 and 36, to which are detachably connected: brightness sensor 23, flash unit 24, or film cassette holder 25, each over a multicore electrical cable 37, 38 or 39 for the electric data transmission in either direction. Another multipole electrical connection 40 for the data transmission is provided automatically between film cassette holder 25 and film cassette 26 if the latter is inserted into the cassette holder. However, instead of via cable 39, cassette holder 25 and cable 40, the film cassette 56 may also be connected directly to connector 36 of exposure computer 22 by means of a multicore cable 41 indicated in FIG. 1 by the broken line.
Camera control unit 21 is likewise provided with some multipole connectors 42-45. The shutter control device 27 is detachably connected to connector 42 by means of a multicore cable 46, while connector 43 is connected to power pack 28 via cable 47. The connector 44 enables the connection of synchronization cable 48 of a flash unit 49. Finally, connector 45 serves to connect a multicore connecting cable 50 leading to a film cassette 51 provided with units for the motor-driven film transport.
If the above-mentioned film cassette 26 has devices for the motor-driven film transport, the film cassette 51, indicated by the broken line, is dispensed with and connecting cable 50 is replaced by connecting cables 39, 40 and 41.
Control unit 21 has electrical circuitries to control the shutter and the lens diaphragm of a photographic camera in which the shutter and the diaphragm can be operated or adjusted by electric signals. Devices for indicating the exposure time and the lens aperture are also provided in control unit 21. Advantageously, control unit 21 can be integrated in a front part of a universal box camera containing the shutter and a stop-setting mechanism, as exemplified by the camera shutter of Sinar AG Schaffhausen, Feuerthalen (Switzerland) sold under the name "SINAR DIGITAL". A camera front part of the above type is illustrated in FIG. 2 and will be described below for a more complete understanding of the invention.
Front part 60 of the camera illustrated in FIG. 2 is shown in a rear view, that is, viewed from the side on which are located holding means 61 and 62 to attach a camera bellows (not shown). Camera front part 60 has a light-admitting aperture 63 through which is visible in FIG. 2 the iris stop 64 of a camera lens 65, which is detachably and interchangeably mounted to the front side. In the interior of camera front part 90 there is provided a shutter 66-69, by means of which light-admitting aperture 63 can be closed to exclude light. Preferably, the shutter is of the type described in German Pat. No. 2 358 929 (U.S. Pat. No. 3,956,761 to Koch et al.) and in German Pat. No. 2 504 912 (U.S. Pat. No. 3,973,269 to Koch et al.). Such shutter has two shutter blades 67, each of which is essentially in the shape of a circular sector and rotating about a common axis 66, and each of which is capable of closing the light-admitting aperture 63 completely. Each shutter blade 67 has two drive mechanisms 68 and 69, by means of which the particular shutter blade can be moved to the open or closed position shown in FIG. 2. An electromotor-driven drive mechanism 70 is further accommodated in the interior of camera front part 60 to adjust iris diaphragm 64 of camera lens 65.
Two manually operated disk-shaped setting mechanisms 71 and 72 for the selection of a desired exposure time for shutter 66-69 or of a desired relative aperture of iris diaphragm 64 are rotatably mounted on the upper part of camera front part 60. The exposure time which is set in each case can be read out from an electrooptical readout panel 73, while the relative aperture selected in each case can be read out in a second electrooptical readout panel 74. Also mounted on the upper part of camera front portion 60 are three manually operated sliding handles 75, 76 or 77 to operate electric switches, which will be described further below. The first sliding handle 75 serves to close and open the shutter; the second sliding handle 76 serves to switch on and off a double exposure lock; the third sliding handle 77 is used to selectively shift the time of the flashlight ignition at the start or shortly before the end of the exposure time set in each case.
Finally, FIG. 2 shows the connectors 31 and 42-45 mentioned earlier with reference to FIG. 1. The details of control unit 21 (FIG. 1) contained in camera front part 60 will be described later.
Exposure computer 22 (FIG. 1) is an essential component of an exposure computer module 80, which in FIG. 3 is shown as viewed from the operating side. Module 80 has five manually operated disk-shaped setting mechanisms 81-85, which are rotatably mounted. The first setting mechanism 81 is coupled to a rotatable dial 86 surrounded by a stationary scale 87. This setting element enables the manual input of the speed of the film material employed.
The second setting mechanism 82 is coupled to a rotating dial 88 surrounded by a stationary scale 89. This setting mechanism 82 enables a code digit to be input in order to take into consideration the so-called Schwarzschild behavior of the film material utilized, that is, the nonlinear correlation between brightness and exposure time for photographic shots with fairly long exposure times.
The third setting mechanism 83 is coupled to a rotating dial 90 surrounded by a stationary scale 91. This setting mechanism 83 permits the selecting setting of exposure computer 22 for different types of brightness measurement, namely, "single-point measurement", "two-point measurement", or "multiple-point measurement", each of the illumination of the subject to be photographed, either with continuous light or with flashlight, as well as "single-point measurement", "two-point measurement", or additional "information measurement" for illumination of the subject with mixed light, i.e., both with continuous light and with flashlight.
The fourth setting mechanism 84 is coupled to a rotating dial 92 surrounded by a stationary scale 93. This setting mechanism 94 permits the photographer to correct, as required, the exposure parameter in 1/3 exposure value steps calculated by exposure computer 22 within a range of, say, +/-3 exposure value steps.
The fifth setting mechanism 85 is coupled by means of an internal gear unit (not shown) to a rotating dial 94. A stationary scale 95 surrounding dial 94 is placed on a transparent carrier, through which dial 94 is visible. The transparent carrier of scale 95 is mounted on a removable and replaceable plate 96. Setting mechanism 85 is used for the manual input of a brightness value which has been determined by means of any photoelectric exposure meter, to which scale 95 has to be adapted. Plate 96 can be replaced by scale 95 in order to be able to match exposure computer 22 to various commonly used exposure meters. As an example, scale 95 can have two sets of values: one set for flashlight and another set for continuous light.
In the upper portion of exposure meter module 80 are placed two electrooptical display panels 97 and 98, which give useful hints to the photographer for flash photography. The first display panel 97 indicates to him the number of identical consecutive flashes needed for a given shot and indicates after each flash how many additional flashes are still necessary. The second indicator panel 98 alerts him on any correction that may be necessary for the flash illumination provided or for the preselected exposure values, which will be explained in more detail below.
Four push buttons 101, 102, 103 and 104 are further provided on exposure computer 80 to actuate electrical contacts, which will be described later. When the first push button 101 is depressed, the data set by means of setting mechanism 85 are stored in exposure computer 22. As soon as the second push button 102 is depressed, the difference between the exposure values resulting from two previous brightness measurements is shown in display panel 83, if for these brightness measurements exposure computer 22 has been prepared for a two-point or multiple-point measurement by means of setting measurement 83. By depressing the third push button 103, the result of checking or information brightness measurements is indicated by exposure computer 22, if the latter is set by means of setting mechanism 83 for the "mixed light" and "information measurement" mode. The result of such checking or information measurement is shown in display panel 73 in the form of an exposure value differential in relation to the previously performed single-point or two-point brightness measurement and does not affect the measuring results obtained previously. The fourth push button 104 serves to switch off the power supply of the whole apparatus.
A sliding handle 105 for operating an electrical switch serves for the selective programming of exposure computer 22 for brightness measurements in the image plane of the camera with the lens diaphragm fully open ("open diaphragm") or with a preselected relative aperture ("working aperture"). At the same time, on account of the position of sliding handle 105, drive mechanism 70 (FIG. 2) for adjusting iris diaphragm 64 is controlled automatically in such a way that the iris diaphragm is fully opened during the brightness measurements or is stopped down to the preselected aperture value.
Finally, FIG. 3 also shows the plug connectors 32, 34, 35 and 36 mentioned above with reference to FIG. 1. The details of the electric circuitry of exposure computer 22 will be described later.
The description of the electric circuitries of the control unit 21 contained in the front part 60 of the camera will be given below. As apparent from the block diagram in FIG. 4, the camera control unit 21 has an electronic logic element 130 in the form of a microprocessor with various signal inputs and outputs, as well as a circuitry 131 for the electric supply. Logic element 130, in turn, comprises a first microprocessor module 133, e.g., of the commonly used type CPU F 3850 of Fairchild Camera & Instrument Corporation, San Jose, Calif. (U.S.A.), a second microprocessor module 134, e.g., of the PIO F 3861 type of the same manufacturer, and a third microprocessor module 135, e.g., of the PSU F 3851 type of the same firm. Each of these microprocessor modules 133-135 is connected via an individual bidirectional data transmission path 136, 137 or 138 to a power line 139 for bidirectional data transmission. The blocks designated in FIG. 4 by the reference numerals 140, 141 and 142 symbolize electrical circuitries, which are shown individually and in greater detail in FIG. 5, 6 or 7. FIG. 4 also shows the plug connectors 31 and 42-25 mentioned above.
FIG. 5, which shows the details of block 140 (FIG. 4), again illustrates the first microprocessor module 133 and the circuitry 131 provided for the electrical supply. Circuitry 131 is connected to power pack 28 by means of connector 43 and has a fuse 146, a relay 147 with an associated normally-open contact 148, a voltage monitoring unit 149, a voltage regulator 150, a switching transistor 151, a diode 152, a resistor 154, and a clock generator 153 to control the timing of microprocessor modules 133-135. Voltage regulator 150 delivers a positive supply voltage of 12 V to an input A of microprocessor module 133 and positive supply voltage of 5 V to an input B of module 133. Clock generator 153 supplies the clock pulses to a signal input T of microprocessor module 133. An input C of the latter is connected to voltage monitor 149 and an input D is connected to the collector of transistor 151 over diode 152 and resistor 154. An output E of microprocessor module 133 is connected to the base of transistor 151, while the emitter of transistor 151 is connected to ground. The excitation coil of relay 147 is connected between resistor 154 and the fuse 146 connected to the positive pole of power pack 28. Normally-open contact 148 of relay 147 is located