Exposure control apparatus for camera

There is disclosed an exposure control apparatus for a camera, enabling appropriate exposure control for varied photographing situations. The apparatus determines the optimum exposure value, referring to various conditions including the season and time of photographs, photographing location, sunrise/sunset times and so on.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an exposure control apparatus for camera, 
and more particularly to determination of exposure in consideration of 
season or sunrise/sunset time. 
2. Related Background Art 
Automatic exposure control of a camera is generally achieved by detecting 
the brightness of an object with a light metering device, determining an 
exposure value based on said object brightness and the sensitivity of the 
photographic film used, and driving the diaphragm and the shutter 
according to said exposure value. 
However, in such exposure determination based solely on the information on 
object brightness and that on film sensitivity, the atmosphere on the 
printed photograph is often significantly different from that actually 
felt by the photographer, because the exposure is usually so determined as 
to obtain a constant amount of exposure to light. For example a scene in 
the evening dusk can be reproduced as an unnatural photograph as light as 
in the daytime. 
Also a camera incorporating an electronic flash device automatically giving 
flash in response to the detection of object brightness executes a 
photographing operation with flash emission automatically to a relatively 
dark object, for example an object in the evening dusk. For this reason 
the evening tone intended by the photographer cannot be obtained on the 
photograph. 
The photographer may manually correct the exposure or prohibit the flash 
emission in order to prevent such situations, but such manual operations 
are not only cumbersome but require experience for obtaining an 
appropriate exposure. 
On the other hand, a photographing operation with strong background 
illumination, such as back-lighted photographing on the sunny summer beach 
or photographing with snow in the background, results in so-called 
underexposed photograph in which the main object appears undesirably dark. 
Such phenomenon is particularly conspicuous in a reversal film with a 
narrow latitude than in a negative film which generally has a relatively 
wide latitude. 
SUMMARY OF THE INVENTION 
The object of the present invention is to provide an exposure control 
apparatus for use in a camera, enabling appropriate exposure control for 
various photographing situations. 
In a preferred embodiment of the present invention, there is provided means 
for detecting the season at the photographing operation, and the exposure 
control apparatus determines the exposure based on the object brightness 
and the detected season. For example in the back-lighted photographing on 
the sunny summer beach or with snow in the background, the exposure is 
automatically so determined as to give an over-exposure. 
Also there is provided means for detecting the time of photographing 
operation, and the exposure is determined according to the object 
brightness and the detected time. For example, if the time detecting means 
detects a twilight time, the exposure control apparatus determines an 
exposure value at the underexposed side by a predetermined amount in 
comparison with the normal state. Thus the tone of morning or evening 
sunshine at the sunrise or sunset can be reproduced on the photograph 
without manual exposure correction. 
In a preferred embodiment of the present invention, there is provided means 
for prohibiting the function of the electronic flash device in the 
twilight situation, in order to reproduce the tone of morning or evening 
sunshine at the sunrise or sunset. 
Furthermore, even on a same data or at a same time of the day, the exposure 
condition may be different because of the difference in season or in 
sunrise/sunset time depending on the location of photographing or other 
photographing situation. For example the appropriate exposure is 
different, depend-on whether the location is in the Northern or Southern 
hemisphere, or on the difference in longitude and/or in latitude even in a 
same country, or on whether the daylight saving time is used. 
Consequently the exposure control apparatus constituting another preferred 
embodiment of the present invention comprises calendar means for measuring 
date and time, means for entering geographic information, means for 
identifying season by correcting the date and time of the calendar means 
according to the geographic information, and means for exposure correction 
based on thus identified season. There is also provided means for 
recognizing sunrise and sunset times, based on said entered geographic 
information and said corrected date and time, and the exposure correction 
is made according to said sunrise/sunset time. Said geographic information 
can be given by the information on longitude and latitude, or by a city 
name. 
Also in a preferred embodiment of the present invention, the exposure 
control apparatus comprises means for recognizing the height of sun at the 
photographing location based on said date and time, and said information 
on longitude and latitude of the photographing location, and applying 
correction to the exposure value when the height of sun is within a 
certain range. For example, the correction on the exposure value is made 
when the height of sun is within a low range or a high range. 
In still another embodiment of the present invention, the exposure control 
apparatus is equipped with means for discriminating whether the 
photographing operation is conducted indoors or outdoors, and the exposure 
value is corrected according to the result of said discrimination, in 
combination with whether the photographing time corresponds to a twilight 
time and whether the season is summer or winter. For example, the exposure 
value is determined at the underexposed side by a predetermined amount in 
an outdoor photographing operation in the twilight, or at the overexposed 
side by a predetermined amount in an outdoor photographing operation in 
the summer or winter daytime.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
At first a first embodiment of the present invention will be explained with 
reference to FIGS. 1 to 5. 
Referring to FIGS. 1 and 2, on the front face of a camera housing 1 there 
are provided a lens barrel 3 having a phototaking lens 2, a finder 
objective lens 4, range-finding windows 5a, 5b for active auto focusing, 
and a light emitting window 41 for electronic flash. On the front face of 
the lens barrel 3 there is provided a photosensor 6 for light metering. 
Said photosensor 6 receives the light in a central area and in a 
peripheral area of the object field, and converts said lights into 
electrical signals. On the upper face of the camera housing there are 
provided a shutter release button 7, a display window 8 of a liquid 
crystal display for displaying the number of photographed film frames or 
the set state of various modes, a mode switching button 9 for the 
electronic flash device, and a mode setting button 10 for setting an 
exposure correction mode to be explained later. 
Also as shown in FIG. 2, a view-finder eyepiece 11 is provided on the rear 
face of the camera housing 1. Inside a rear cover 12 which can be opened 
from the camera housing 1, there is provided a data back (not shown) for 
recording date and time on the film, said data back incorporating a timer 
circuit for measuring date and time. On the outer face of the rear cover 
12 there are provided a display device 13 for displaying the data to be 
recorded by said data back push-buttons 14 for selecting the date or time 
to be recorded or setting such date and time, and a window 15 for reading 
the kind of film printed on the loaded film cartridge. 
FIG. 3 shows a state with open rear cover 12. In a film chamber 21 in the 
camera housing there are provided DX contacts 22, which come into contact 
with DX code contacts provided on the surface of the film cartridge when 
it is loaded in the film chamber 21. The DX code contacts are provided for 
representing film information by the positions of contacts, and are 
already known. Said film information is data specific to the photographic 
film, such as the kind of film (negative or reversal) and the film 
sensitivity. 
The camera housing 1 and the rear cover 12 are respectively provided with 
contacts 23 and contact pins 24, which mutually contact when the rear 
cover is closed, thereby enabling signal transmission between the 
above-mentioned data back and a CPU provided in the camera housing. In 
FIG. 3, there are further shown an exposure aperture 25, a spool 26, and 
an idler sprocket for film wind/rewinding. 
FIG. 4 is a block diagram of the exposure control apparatus for camera. 
To the CPU 31 for controlling the sequence in the entire camera, there are 
connected a light measuring circuit 32, a range-finder circuit 33, an 
exposure control circuit 34, a flash control circuit 51 of an electronic 
flash unit 50, and switches SW1, SW2. 
The light measuring circuit 32 is connected to the photosensor 6 mentioned 
above, receives electrical signals therefrom, corresponding to the amounts 
of light in the central area and peripheral area of the object, calculates 
the brightness of the object based on said electrical signals, and sends 
the result of said calculation to the CPU 31. 
The range-finder circuit 33 detects the distance to the object by a known 
active range-finding method, and sends the obtained result to the CPU 31. 
The exposure control circuit 34 controls the function of unrepresented 
diaphragm and shutter in response to an instruction from the CPU 31, 
thereby executing the photographing operation. 
The flash control circuit 51, to which a flash emission tube 52 is 
connected, accumulates an electric charge necessary for the flash emission 
from said flash tube 52 is an unrepresented main capacitor in response to 
an instruction from the CPU 31, and controls the flash emission from said 
flash tube 52 at the flash photographing operation to be explained later. 
The switches SW1, SW2 are linked with the shutter release button 7, and are 
respectively closed when said button 7 is depressed to a first stroke 
position and a second stroke position. 
Also the above-mentioned DX contacts 22 are connected to the CPU 31, for 
entering the film information to the CPU 31. 
Furthermore, when the rear cover 12 is closed, the timer circuit 35 of the 
data back provided in said rear cover 12 is connected to the CPU 31 
through the contact 23 and contact pins 24, thus entering information on 
date and time to the CPU 31. 
In the following there will be explained the control sequence of the CPU, 
with reference to a flow chart shown in FIG. 5. 
The program shown in FIG. 5 is activated when the exposure correction mode 
is selected by the mode selector button 10 and the switch SW1 is closed by 
the actuation of the shutter release button 7. At first a step S1 executes 
range finding and light measuring, by activating the range-finder circuit 
33 and the light measuring circuit 32, and reading the object distance and 
the object brightness respective therefrom. Then a step S2 calculates the 
exposure value EV from said object brightness and the film sensitivity 
entered from the DX code contacts of the loaded film cartridge through the 
DX contacts 22. Said exposure value EV becomes larger for a higher 
brightness of the object, for a given film sensitivity. 
A next step S3 discriminates whether the calculated exposure value exceeds 
13 EV, and, if not, the sequence proceeds to a step S4. Said step S4 
discriminates whether the calculated exposure value EV exceeds 9 EV, and, 
if not, a step S5 discriminates whether the exposure value exceeds 7 EV. 
If the discrimination of the step S5 turns out negative, namely if the 
exposure value is equal to or lower than 7 EV, the sequence proceeds to a 
step S10 for awaiting the closing of the switch SW2. On the other hand, if 
said discrimination turns out affirmative, namely if the exposure value is 
larger than 7 EV but equal to or less than 9 EV, the sequence proceeds to 
a step S6. 
The step S6 discriminates, by reading the current time from the timer 
circuit 35, whether the current time is in the morning or in the evening, 
namely a twilight time. The discrimination of twilight time is made by 
whether the current time is included within predetermined ranges, which 
may be varied according to the season of the year. 
If the step S6 gives an affirmative result, a step S51 discriminates, based 
on the film information entered through the DX contacts 22, whether the 
loaded film is a reversal film or a negative film. Since the reversal film 
has a narrower exposure latitude than in the negative film, said step S51 
identifies whether the film has a wide or narrow exposure latitude. 
If the step S51 identifies a reversal film, a step S52 corrects the 
exposure value, calculated in the step S2, to the under-exposure side by 
0.5 EV, but if a negative film is identified, a step S53 corrects said 
exposure value to the under-exposure side by 1 EV, and the sequence 
proceeds to a step S7. On the other hand, if the step S6 gives a negative 
result, the sequence proceeds to a step S10. 
On the other hand, if the step S3 identifies that the exposure value 
exceeds 13 EV, indicating that the object is very light, the sequence 
proceeds to a step S13 for discriminating, based on the time obtained from 
the timer circuit 35, whether the current time is daytime. If the result 
of the step S13 is negative, the sequence proceeds to the step S7. If said 
result is affirmative, a step S14 discriminates, based on the data 
obtained from the timer circuit 35, whether the current season is summer 
or winter, or other season. If it is summer or winter the sequence 
proceeds to the step S7, but, if it is neither summer nor winter, the 
sequence proceeds to a step S15. 
The step S15 discriminates, based on the film information entered from the 
DX contacts 22, whether the loaded film is a reversal film or a negative 
film. If a reversal film is identified, a step S16 corrects the exposure 
value, calculated in the step S2, to the over-exposure side by 0.5 EV, 
while, if a negative film is identified, a step S17 corrects said exposure 
value to the over-exposure side by 1 EV, and the sequence proceeds to the 
step S7. 
The step S7 discriminates whether the switch SW2 is closed, if not, a step 
S8 discriminates whether the switch SW1 is closed. If it is closed the 
sequence returns to the step S7, but, if it is not, the sequence is 
terminated. 
When the step S7 identifies that the switch SW2 is closed, a step S9 
executes the photographing operation by driving the phototaking lens 2 to 
a predetermined in-focus position by an unrepresented focusing motor based 
on the object distance read in the step S1, and then driving the diagram 
and the shutter according to the exposure value obtained in the step S2, 
S16, S17, S52 or S53. Thereafter the film is advanced by a frame by an 
unrepresented film winding motor, and the sequence is terminated. 
Also the step S10 similarly awaits the closing of the switch SW2, and, when 
it is closed, a step S12 executes a flash photographing operation, by 
focusing the phototaking lens 2 as explained above, then exposing the film 
by driving the diaphragm and the shutter according to the exposure value 
for the flash photographing determined in advance, and at the same time 
causing flash emission from the flash tube 52 by means of the flash 
control circuit 51. Thereafter the film is advanced by a frame by the 
unrepresented winding motor, and the sequence is terminated. 
In the above-explained sequence, the exposure value EV calculated in the 
step S2 is classified into four ranges 13&lt;EV, 9&lt;EV.ltoreq.13, 
7&lt;EV.ltoreq.9, and EV&lt;7, and the exposure value at the photographing is 
controlled as follows in each range: 
Case of 13&lt;EV: 
This is the case of a very bright object, and the exposure value EV is 
automatically corrected in the following manner if the photographing is 
conducted in the daytime and in summer or in winter. In this case, the 
exposure value is corrected to the over-exposure side by 0.5 EV in case of 
the reversal film with narrower latitude, or by 1 EV in case of the 
negative film with wider latitude. Such correction prevents the 
underexposure in the conventional photographing, even on the beach in a 
fine summer day or in a snow scene in winter. However, even in case of 
13&lt;EV the above-mentioned correction is not conducted if the photographing 
time is not summer nor winter, or not in the daytime. 
Case of 9&lt;EV.ltoreq.13: 
In this case the photographing is conducted according to the exposure value 
EV calculated in the step S2. 
Case of 7&lt;EV.ltoreq.9: 
This is so-called twilight situation, and the exposure value is corrected 
if the photographing time is in the morning or evening, to the 
underexposure side by 0.5 EV in case of the reversal film of narrower 
latitude, or by 1 EV in case of the negative film with wider latitude. In 
addition, in this case (in the morning or evening), the flash emission of 
the electronic flash unit 50 is prohibited. The tone of the morning 
sunlight or evening sunlight can be reproduced on the photograph by the 
exposure correction and the prohibition of function of the electronic 
flash unit 50 explained above. 
If the photographing time is not in the twilight time, the exposure value 
is not corrected and the electronic flash unit emits flash light. 
Case of EV.ltoreq.7: 
In this case the photographing operation is conducted with flash, since the 
object is considerably dark. In summary, flash light emission is conducted 
by the electronic flash unit usually when the exposure value is equal to 
or less than 9 EV, but, in the twilight situation, when the exposure value 
is equal to or less than 7 EV. Stated otherwise, the reference exposure 
value for effecting flash emission is shifted to the darker side by 2 EV 
in the twilight situation. 
The above-explained EV discrimination process (steps S3-S5) of the present 
embodiment is the case of a film sensitivity of ISO 100, but the EV for 
discrimination varies if the sensitivity of the loaded film is different 
from ISO 100. More specifically, the EV for discrimination becomes higher 
or lower than ISO 100, respectively for a film of higher or lower 
sensitivity. 
Said EV used for discrimination may be determined in consideration of the 
film latitude, in addition to the film sensitivity. FIG. 6 shows a flow 
chart for such case, which is designed for a film sensitivity of ISO 100, 
and in which same steps as those in FIG. 5 are represented by same 
numbers. 
In the following there will be explained the flow chart in FIG. 6, with 
emphasis on the difference from FIG. 5. This program is started when the 
switch SW1 is switch SW1 is closed by the actuation of the mode selector 
button 10. At first a step S1 executes range-finding and light measuring. 
Then a step S61 reads the film information through the DX contacts 22, and 
extracts the information on the film sensitivity. The exposure value is 
calculated from said film sensitivity and the object brightness obtained 
by said light measurement, and the sequence proceeds to a step S62. The 
step S62 discriminates whether the loaded film is a reversal film or a 
negative film based on said film information, and the sequence proceeds to 
the step S3 for executing the procedure explained above in case of the 
negative film, or to a step S63 in case of the reversal film. 
Steps S63, S64 and S65 constitute, corresponding to the above-mentioned 
steps S3, S4 and S5, an EV discrimination process utilizing ranges defined 
by EV 13, EV 9 and EV 7 for a negative film but by EV 14, EV 9 and EV 7 
for reversal film. Because the reversal film has a wider latitude in the 
underexposure side than the negative film a positive correction is applied 
to the reversal film in case of a highly bright object. 
Steps S68 and S69 are similar to the steps S13 and S14. When the step S69 
provides an affirmative discrimination, a step S70 corrects the exposure 
value by -0.5 EV. A step if a step S66, similar to the step S6, provides 
an affirmative discrimination, and a step S67 corrects the exposure value 
by -0.5 EV. 
The above-explained case applies to a film of ISO 100, but the EV's for 
discrimination become larger or smaller respectively for a film of higher 
or lower sensitivity. 
In the foregoing explanation, the correction on the exposure value is based 
on the season, time and kind of film, but other factors such as color 
temperature of the object and direction of the camera may be detected for 
identifying the forward or back lighted condition, thereby enabling more 
precise exposure correction. Also exposure correction in further 
consideration of the object distance allows approximate identification 
whether the object is a person or a scene, thereby providing more accurate 
correction. Still other factors such as temperature, humidity, air 
pressure, longitude, latitude etc. may be added in the correction of the 
exposure value. 
It is furthermore possible to modify the exposure value stepwise by 
dividing the time more finely, to determine the exposure value by applying 
fuzzy theory. 
Furthermore, instead of correcting the calculated exposure value EV, it is 
also possible to apply correction for example to the object brightness 
obtained by the light measuring circuit. 
In the following there will be explained a second embodiment of the present 
invention. 
FIG. 7 schematically shows an exposure control apparatus constituting a 
second embodiment, in which a date controller circuit C1 has a data bank 
for time difference correction, in addition to known circuits such as a 
clock circuit for measuring date and time and having calender function, a 
display control circuit for driving a display unit L1, and a data 
recording control circuit for driving a data recording device L2. As will 
be explained later, the date control circuit C1 is constructed as to 
recognize the season based on the measured date and time, and to recognize 
the sunrise and sunset times based on the date, time and geographic 
information. 
There are also provided a camera control circuit C2 for controlling the 
drive sequence of the camera, and an exposure control device E for 
controlling the shutter and the diaphragm of the camera. 
As shown in FIG. 8, the display unit L1 is provided with a display area 101 
for indicating a time difference correction code, a display area 102 for 
indicating the daylight saving time, a display area 103 for indicating the 
completion of data recording, a display area 104 for indicating a 
correction number for the latitude, a display area 105 for indicating a 
correction number for the longitude, and a display area 106 for 
selectively indicating year, month and date or date, hour and minute. 
The data recording device L2 records the data displayed on the display unit 
L1 into a recording medium such as the photographic film or a CCD. 
Eight operating switches SW1-SW8 are connected to the date controller 
circuit C1. The switches SW1, SW2 are provided for entering a correction 
code for time difference. Certain cities of the world are selected in 
advance as references, and a time difference correction code represented 
by two-digit number is assigned to each city, for example 21 for Tokyo, 20 
for Beijin and04 for Los Angeles. The geographic information is entered 
into the date controller circuit C1 by said correction code. Thus the time 
difference is automatically corrected, based on a map stored in advance in 
the date controller circuit C1, according to the correction code entered 
by the switches SW1, SW2. 
Said map stores said correction code and a time difference corresponding to 
the reference city indicated by said correction code, in pair. The 
switches SW1 and SW2 respectively enter the places of 10 and 1 of the 
code, and it is convenient if each switch increases the figure stepwise at 
each actuation. The entry of the geographic information is not limited to 
the entry of the above-mentioned correction codes, but may also be 
achieved by the direct entry of names of cities or locations, or by 
pointing of suitable locations on a displayed world atlas, as in the 
conventional so-called world clock. In any method, the time difference is 
corrected by the entered geographic information, whereby the date and time 
measured by the clock device vary. 
The switch SW3 is provided for setting a daylight saving time mode, and the 
normal time mode and the daylight saving time mode are alternated by 
repeated actuations. When the daylight saving time mode is selected, the 
time measured by the clock device is corrected by a predetermined amount. 
The switches SW4, SW5 are provided for correcting the latitude and 
longitude. When the sunrise/sunset times determined from the date and time 
corresponding to the time difference correction code selected by the 
switches SW1, SW2 is different from the actual sunrise/sunset times, 
namely when the photographing location is distant from the reference city 
corresponding to the time difference correction code, said times are 
corrected by the manipulation of the switches SW4, SW5. 
The correction with the switches SW4, SW5 is achieved by the entry of 
positive or negative values corresponding to the differences in latitude 
and longitude from the entered reference city. For example, if the 
sunrise/sunset times are determined in the Pacific standard time of the 
U.S.A., taking Los Angeles as reference, these times in Seattle located at 
North are different. The above-mentioned correction for latitude and 
longitude is conducted for compensating such difference in the 
sunrise/sunset times. 
The switch SW6 is used for switching the display mode, and changes, at each 
actuation, the display mode of the display unit L1, for example 
year-month-day, month-day-year, day-month-year, day-hour-minute and off 
(no display) in cyclic manner. 
The switch SW7, which is a selector switch, selects the correction mode at 
the first actuation, and then shifts the digit to be corrected stepwise at 
each subsequent actuation. 
The switch SW8 varies stepwise the figure of the digit selected by the 
selector switch SW7. 
FIG. 9 shows the flow chart of season recognition. The boundary between the 
seasons is defined for example by spring equinox, summer solstice, autumn 
equinox, winter solstice, or the feeling of season in each city. 
A step S1 discriminates whether the season is spring, based on the date 
measured by the clock device, and, if it is spring, the exposure 
correction mode to be explained later is set at the spring mode, or, if it 
is not spring, the sequence proceeds to a step S3 for discriminating 
whether the season is summer. Thereafter the summer, autumn and winter are 
discriminated and the exposure correction mode is set at a corresponding 
mode (steps S4-S8). In case of indoor or night photographing, the normal 
mode is set instead of the above-mentioned exposure correction mode (step 
S9). 
FIG. 10 is a chart indicating the relation between the exposure value and 
the object brightness in the exposure correction mode corresponding to the 
season recognized as explained above, wherein the abscissa indicates the 
object brightness LV and the ordinate indicates the exposure value EV. 
In the spring mode, the exposure is slightly corrected to the over-exposure 
side for an object with light value LV exceeding 9, thereby reproducing 
the object relatively light and expressing the atmosphere of spring. 
In the summer mode, the exposure is corrected further to the over-exposure 
side than in the spring mode, thus expressing the dazzling sunshine of 
summer. 
In the autumn mode, the exposure is maintained at the substantially 
standard state. 
In the winter mode, the exposure is corrected to the under exposure side, 
thereby giving a generally dark tone in the photograph. Most 
characteristics of this mode is that the exposure for an object with LV 
exceeding 15 is corrected to the over-exposure side. Since such object is 
a snowed scene, such correction is suitable for reproducing the snow in 
white color. In photographing in the areas close to the equator, the 
summer mode is almost always selected, so that the above-explained 
exposure mode in consideration of snow is not required. 
FIG. 11 is a flow chart for discriminating sunrise/sunset times, for 
determining the exposure correction mode by discriminating whether the 
current time is close to the sunrise or sunset time. 
As explained before, the sunrise/sunset times are identified from the date 
and the geographic information, namely from the time difference correction 
code and the correction values for latitude and longitude. At first a step 
S10 discriminates whether the current time is close to the sunrise time, 
and, if it is close, the exposure correction mode is set at the sunrise 
mode (step S11). If the current time is not close to the sunrise time, a 
step S12 discriminates whether it is close to the sunset time, and, if it 
is close, a step S13 sets the exposure correction mode at the sunset mode. 
If, the current time not close to the sunrise time nor to the sunset time, 
a step S14 selects the normal mode. 
FIG. 12 shows the relation between the exposure value and the object light 
value, in the exposure correction mode corresponding to the sunrise/sunset 
times recognized as explained above. A curve a indicates the amount of 
exposure correction for the sunset situation, wherein a figure "0" 
indicates the moment of sunset and other figures indicate hours before or 
after the sunset, and the ordinate indicates the exposure value EV. The 
exposure is corrected to the under-exposure side, at and around the 
sunset, in order to reproduce the scene in the twilight. 
A curve b indicates the amount of exposure correction for a sunset 
situation wherein the sun is included in the image frame. In such case the 
exposure is corrected further to the under-exposure side. The presence of 
the sun in the image frame can be discriminated for example by a multiple 
light measuring system disclosed in the U.S. Pat. No. 4,443,080. 
The exposure correction for the sunrise situation is similar to that shown 
in FIG. 12, but the normal mode is restored after a shorter time after the 
sunrise than in the sunset. 
FIGS. 13 and 14 show the displays of year-month-day and day-hour-minute on 
the display unit L1 in case Tokyo is selected by the correction code. 
FIG. 15 shows the display in case a time difference correction code for 
Sidney is selected in the state shown in FIG. 14. In this case the time 
difference between Sidney and Tokyo is 1 hour. However, since Tokyo is in 
the Northern hemisphere while Sidney is in the Southern hemisphere, the 
internal season recognizing logic recognizes a season opposite to that of 
Tokyo. 
FIG. 16 shows a case of selection of Los Angeles. As Los Angeles is in the 
daylight saving time, there is selected the daylight saving time mode, as 
indicated by DST mark. 
FIG. 17 shows the case of Seattle, which employs the U.S. Pacific standard 
time as in Los Angeles, but is distant therefrom. The time difference 
correction code "04" is same as that for Los Angeles. Los Angeles is 
approximately located at a latitude 34.degree. N and a longitude 
118.degree. W, while Seattle is approximately located at a latitude 
47.degree. N and a longitude 122.degree. W. Thus the sunrise/sunset times 
are corrected by entering +13.degree. in latitude and +4.degree. in 
longitude, taking Los Angeles as reference. The sunrise/sunset times are 
so corrected as to match the actual phenomenon that the time from sunrise 
to sunset in Seattle is longer in summer and shorter in winter than that 
in Los Angeles. 
In the following there will be explained the function of the present 
embodiment. 
FIG. 18 is a flow chart of the sequence for correcting the exposure by 
recognizing the time difference and the season through the entry of 
geographic information. 
At first the time difference correction code corresponding to the reference 
city, namely the geographic information, is entered by the switches SW1, 
SW2 (step S21). Then the time difference from the current time is 
calculated from said correction code and displayed (step S22). The season 
is recognized as already explained in relation to FIG. 9, based on the 
date read from the clock device (step S23), and the exposure correction is 
made as shown in FIG. 10 (step S24). 
FIG. 19 is a flow chart of the sequence for correcting the exposure, by 
recognizing the time difference and the sunrise/sunset times through the 
entry of the geographic information. 
At first, as in the above-explained steps S21, S22, the time difference is 
corrected and displayed (steps S31, S32). Then the sunrise/sunset times 
are recognized (step S33). The exposure correction mode is set through the 
recognition of the difference between the current time and the 
sunrise/sunset times according to the function shown in FIG. 11 (step 
S34), and the exposure correction is made according to the chart shown in 
FIG. 12 (step S35). 
FIG. 20 is a flow chart of the sequence for correcting the exposure by 
recognizing the time difference and the sunrise/sunset times through the 
entry of geographic information with correction for latitude and 
longitude. 
At first, as in the above-explained steps S31, S32, the time difference is 
corrected and displayed (steps S41, S42). Then there is discriminated 
whether the correction switches SW4, SW5 have been actuated (step S43), 
and, if the latitude and/or longitude is corrected, the sunrise/sunset 
times are recognized according to the corrected geographic information 
(step S44). Thus the difference between the recognized sunrise/sunset 
times and the current time is calculated (step S45), and the exposure 
correction mode is set according to the sequence shown in FIG. 11, based 
on the result of said calculation and the exposure correction amount EV1 
is obtained (step S46). Then the season is recognized according to the 
sequence shown in FIG. 9, based on the date read from the clock device 
(step S47), and the exposure correction amount EV2 is calculated according 
to the chart shown in FIG. 10 (step S48). Finally the exposure correction 
amount EV is determined by adding the amount EV1 determined in the step 
S46 and the amount EV2 determined in the step S47 (step S49). 
If the correction for latitude or longitude is not made in the step S43, 
the sunrise/sunset times are recognized from the initially entered 
geographic information (step S50), and the sequence proceeds to the step 
S45. 
The correction for latitude and longitude in the above-explained embodiment 
consists of entry of a time difference correction code and then entry of 
correction data for latitude and longitude for a location distant from the 
reference city corresponding to said time difference correction code, but 
it is also possible to directly enter the latitude and longitude of a 
desired location. Also cities distant-from the reference cities may be 
stored as a map in the internal memory for enabling the time difference 
correction without entry of the time difference correction code, or 
inversely a city may be displayed by the latitude/longitude data entered. 
Also the cumbersome entry of cities may be simplified by inserting, into 
the camera, one of IC cards representing geographic regions and storing 
representative locations. 
Also if the sunrise/sunset times alone are considered, such times alone may 
be memorized even without the world clock. 
It is furthermore possible to effect the photographing operation with 
normal exposure without correction but to record the calculated exposure 
correction value for example on the film, and to apply a corresponding 
correction at the image reproduction, for example at photographic 
printing. It is furthermore possible to record the photographing location, 
date and time, and to apply the corresponding correction at the printing 
by means of a printer incorporating the above-explained algorithm for 
exposure correction. 
In case the exposure is correction according to the sunrise/sunset times or 
the season, further correction to the normal state at the printing is 
undesirable. Consequently, for a film frame photographed according to said 
algorithm for exposure correction, a signal for prohibiting the correction 
at the printing is preferably recorded on the film. 
In the following there will be explained a third embodiment of the present 
invention. 
In an exposure control apparatus shown in FIG. 21, a CPU 201 for 
controlling the sequence of the entire camera, is connected, as in the 1st 
embodiment, to an exposure control circuit 202, a light measuring circuit 
203 and a timer circuit 204. A calendar 205, in cooperation with the timer 
circuit 204 provides the CPU 201 with the Greenwich standard time 
(reference time including month and date) G.M.T. A latitude/longitude 
setting circuit 206 gives the latitude and longitude of the photographing 
location in response to the actuation of switches SW25-SW27, while a 
height-above-sealevel setting circuit 207 sends the height above sea level 
of the photographing location to the CPU, in response to the actuation of 
switches SW23, SW24. Switches SW1, SW2 are closed in relation to the 
actuation of the shutter releasing operation as in the foregoing 
embodiments. 
FIG. 22 shows a displayed image of the latitude/longitude setting circuit 
206. At the center of an image frame 210, a world atlas 211 is displayed 
by Mercator presentation, in a range from 60.degree. N to 60.degree. S. 
Above and below said world atlas 211 there are displayed maps 212, 213 of 
Arctic circle and Antiarctic circle. On the world atlas 211 there are 
shown latitude lines and longitude lines at constant intervals, and, below 
and at the right side of the world atlas there are provided symbols A - Z 
and a - i for identifying the areas defined by said latitude lines and 
longitude lines. Also each of the Arctic and Antiarctic maps 212, 213 is 
divided into four quadrants, and said quadrants are given symbols j - k 
and n - q. 
For example, if the photographing location is in the western a part of 
Japan, the switch SW25 is actuated to move the X-moving mark X1 to the 
symbol "V" and the switch SW26 is actuated to move the Y-mark Y1 to the 
symbol "c". By turning on the switch SW27 in this state, there is 
displayed, as shown in FIG. 23, a magnified view of an area specified by 
the symbols V and c. This magnified view 214 also has latitude lines and 
longitude lines in equal distances, and symbols A - H and a - i are shown 
below and at the right side of the display. 
For example, if the photographing location is Hiroshima in this display the 
switch SW25 is actuated to move the X-mark X1 to a symbol D and the switch 
SW26 is actuated to move the Y-mark Y1 to a symbol g. By turning on the 
switch SW27 in this state, the representative latitude and longitude 
(center values) of the area defined by the symbols D and g are specified 
and are given to the CPU. The representative latitude and longitude may be 
the latitude and longitude of a principal city in the defined area. 
Also if the photographing location is in the Arctic or Antiarctic circle 
shown in FIG. 22, the switch SW26 is actuated to move the moving mark Y1 
of the Y-direction to the mark "j" or one of the subsequent marks. For 
example, by positioning the moving mark Y1 at the symbol p and turning on 
the switch SW27, there is displayed, as shown in FIG. 24, a magnified view 
of a quadrant of the Antiarctic circle designated by the symbol p. Said 
magnified view 215 has arc-shaped latitude lines and radial longitude 
lines, and X-symbols A - K and Y-symbols a - h are provided below and at 
the right side of the display, in order to designate sectors defined by 
said latitude lines and longitude lines in the form of coordinate. 
For example, if the photographing location in a hatched area in the 
magnified view 215, the switch SW25 is actuated to move the movable mark 
X1 in the X-direction to a symbol E, and the switch SW26 is actuated to 
move the movable mark Y1 in the Y-direction to a symbol g. By turning on 
the switch SW27 in this state, the representative latitude and longitude 
of the area specified by said symbols E and g (central values of the 
latitude and longitude in the area) are designated and are given to the 
CPU. 
In the foregoing explanation there are employed representative latitude and 
longitude in the area surrounded by latitude lines and longitude lines, 
but, for a certain area around a crossing point of a latitude line and a 
longitude line, the latitude and longitude of said crossing point may be 
taken as representative values. 
The height-above-sealevel setting circuit 207 has a display unit (not 
shown), and displays thereon the height above sea level in the unit of 
meters. Said height display is increased by the unit of 10 meters by each 
actuation of the switch SW23, or by the unit of 100 meters by each 
prolonged actuation thereof, or decreased by the unit of 10 or 100 meters 
by each similar actuation of the switch SW24. The height above sea level 
thus set is supplied to the CPU. 
In the following there will be explained the function and operation of the 
CPU, with reference to a flow chart shown in FIG. 25. 
When the switch SW1 is closed in response to the shutter releasing 
operation, the CPU reads the Greenwich standard time G.M.T. from the timer 
circuit 204 and the calendar 205 (steps S1, S2). Then the CPU reads the 
longitude of the photographing location set by the latitude/longitude 
setting circuit 206 (step S3), and calculates the sun bearing BRG at the 
photographing location, based on said longitude and G.M.T. (step S4). 
Then the CPU reads the latitude of the photographing location designated by 
the latitude/longitude setting circuit 206 (step S5), and calculates the 
height .alpha. of the sun at the photographing location, based on the sun 
bearing and said latitude (step S6). 
The height of the sun mentioned above indicates the height angle o shown in 
FIG. 26. FIG. 26 illustrates the height of the sun at about 1 p.m. at 
spring equinox and autumn equinox in the Northern hemisphere, on the 
equator and in the Southern hemisphere, and said height varies in a range 
-90.degree..ltoreq..alpha..ltoreq.90.degree.. 
After the height of the sun is obtained in the step S6, the CPU reads the 
height above sea level of the photographing location set by the height 
setting circuit 207 (step S7), and calculates the correction value .delta. 
for the height of the sun at the twilight situation, based on said height 
above sea level (step S8). Said correction value .delta. indicates the 
negative angle when the horizon of 0 meter is seen from a high place (FIG. 
27), and is used for correcting the lower limit angle for defining the low 
height range of the sun. 
FIG. 28 shows the relation between the height of the sun and constants A - 
C to be used in the subsequent steps, wherein -A and B are respectively a 
lower limit angle and a higher limit angle defining a low height range of 
the sun, and C is a lower limit angle for defining a high height range of 
the sun. The lower limit angle -A is determined for a time slightly before 
the sunrise or after the sunset. An angle "-A-.delta. ", obtained by 
adding the correction value -.delta. to the lower limit angle -A, is taken 
as the corrected lower limit angle defining the low height range of the 
sun. 
Then the sequence proceeds to a step S9 for discriminating whether the 
height .alpha. of the sun is positioned within a range 
(-A-.delta.).ltoreq..alpha.&lt;B, and, if the sun height is within said 
range, namely if the current height of the sun is within a low height 
range, the CPU read an exposure correction amount .beta. of the 
under-exposure side (step S10), then measures the brightness of the object 
(step S11), determines the exposure value EV based on thus measured object 
brightness and the exposure correction amount .beta. (step S12) and 
executes a phototaking operation in response to the closing of the switch 
SW2. 
On the other hand, if the step S9 identifies that the height .alpha. of the 
sun is outside the above-mentioned range (-A-.delta.).ltoreq..delta.&lt;B, 
the sequence proceeds to a step S15 for discriminating whether the height 
.alpha. is within a range B.ltoreq..alpha.&lt;C. If it is outside said range, 
a step S16 discriminates whether it is within a range 
C.ltoreq..alpha..ltoreq.90.degree.. If it is within said range, indicating 
that the sun is within the high height range, the CPU reads a exposure 
correction value .gamma. of the overexposure side (step S17), and 
determines the exposure value from the object brightness and said exposure 
correction value .gamma.. 
If the step S15 identifies that the height .alpha. of the sun is within the 
range B.ltoreq..alpha.&lt;C, the sequence proceeds directly to a step S11 for 
determining the exposure value EV based on the object brightness. Also if 
the step S16 identifies that the height of the sun is outside the range 
C.ltoreq..alpha..ltoreq.90.+-., there is identified a night time, and an 
exposure correction (a significant correction to the underexposure side) 
is applied to the object brightness, in order to reproduce the impression 
of night (steps S19-S22). 
As explained in the foregoing, the exposure control apparatus of the 
present embodiment applies a correction to the exposure value in the 
under-exposure side when the height .alpha. of the sun is in a low range, 
thereby enabling to reproduce the atmosphere of early morning or evening 
on the photograph. Also when said height is in a high range, the exposure 
value is corrected to the overexposure side, whereby light atmosphere can 
be reproduced on the photograph. For example in case of photographing in 
Japan, the daytime from spring to summer is recognized as the time of high 
sun and the exposure value is corrected to the overexposure side, whereby 
a light scene is reproduced on the printed photograph. On the other hand, 
the daytime from autumn to winter is not recognized as the time of high 
sun, so that the photographing operation is conducted with an exposure 
value of the underexposure side in comparison with that used from spring 
to summer, and a darker and deeper scene is reproduced on the printed 
photograph. 
In addition the present embodiment executes the above-explained exposure 
correction in any location in the world, because the height of the sun 
varying according to the photographing location and photographing time is 
calculated from the designated latitude and longitude and the G.M.T. 
FIG. 29 shows another embodiment of the function and operation of the CPU. 
In comparison with the flow chart shown in FIG. 25, the present embodiment 
is different in steps between the steps S8 and S12. After the calculation 
of the correction value .delta. in the step S8, a step S21 discriminates 
whether the height .alpha. of the sun is within a range 
(-A-.delta.).ltoreq..alpha.&lt;B. If the sun height is within said range, the 
current sun height is judged to be in a low range. Thus an exposure 
correction amount .beta. of the underexposure side is read (step S22) and 
the exposure value is determined from the object brightness and the 
exposure correction amount .beta.. 
If the step S21 identifies that the height of the sun is outside the 
above-mentioned range (-A-.delta.).ltoreq..alpha.&lt;B, the sequence proceeds 
to a step S24 for discriminating whether a condition B.ltoreq..alpha. 
stands. If B&gt;.alpha., a night time is identified and an exposure 
correction is applied to the object brightness for providing the 
atmosphere of night scene (step S33), and then the exposure value is 
determined. In case of B.ltoreq..alpha., there is discriminated whether 
the designated latitude LAT satisfies a condition 0.degree..ltoreq.LAT&lt;D 
(step S25), and, if it is outside said range, the sequence proceeds to a 
step S26 for discriminating whether a condition D.ltoreq.LAT&lt;D wherein D 
and E are constants satisfying a relation D&lt;E and indicating certain 
absolute latitudes regardless of the Northern or Southern latitudes. 
Thus, if a step S25 identifies that the latitude is positioned between a 
Northern latitude D and a Southern latitude D around the equator, here is 
discriminated whether the photographing location is in the Northern 
hemisphere or in the Southern hemisphere, by identifying whether said 
latitude is a Northern latitude or a Southern latitude (step S27), and the 
sequence proceeds to a step S28 or S29 respectively in case of Northern or 
Southern hemisphere. If the step S28 identifies that the current data is 
within a period from April to September, namely from spring to summer, the 
sun height is identified in the high range and an exposure correction 
amount .gamma. of the overexposure side is read (step S30). On the other 
hand, if the step S29 identifies that the current date is within a period 
from October to March, namely from spring to summer, the sun height is 
identified in the high range and an exposure correction amount .gamma. of 
the overexposure side is read. If the current date is outside the period 
from April to September in the step S28 or outside the period from October 
to March in the step S29, the sequence proceeds directly to a step S23. 
Also if the step S26 identifies that the latitude is positioned between 
Northern latitudes D and E or between Southern latitudes D and E and a 
step S31 identifies that the current date is within a period from June to 
September or within a period from December to March, an exposure 
correction value .gamma. to the overexposure side is used. Thus, in case 
of D.ltoreq.LAT&lt;E, the exposure value is corrected to the overexposure 
side within the period from June to September or from December to March, 
without distinction between the Northern and Sourthern hemispheres. 
Therefore, for example, in the Northern hemisphere, the exposure is 
corrected to the overexposure side in the summer from June to September 
and in the winter from December to March, whereby the underexposure 
resulting from snow in the high latitude region. The exposure correction 
amount .gamma. may be varied between summer and winter. 
In the above-explained embodiment, the height above sea level may be 
automatically set in response to the latitude/longitude setting circuit 
206, or in linkage with an altimeter. The above-mentioned embodiment may 
also be provided with sensors for air pressure, humidity and temperature 
for detecting the state of weather, namely fine, cloudy or rainy weather, 
thereby estimating the deviation in the twilight time. For example, in the 
cloudy or rainy weather, the twilight time is deviated from the sunrise or 
sunset time. The low height range of the sun can be regulated according to 
the estimated deviation of the twilight time, whereby an appropriate 
exposure correction can be made according to the state of weather. 
In the following there will be explained a 4th embodiment of the present 
invention. 
Referring to FIG. 30, a light measuring device 330 is provided with a 
photosensor 331 for receiving the light coming from an object through a 
lens 300, a frequency detector 332 for detecting the frequency of the 
output signal of the photosensor, and a circuit 333 for calculating the 
brightness of the object from the output of the photosensor. The object is 
identified to be illuminated by an artificial light source, such as a 
fluorescent lamp, if a particularly frequency (50 or 60 Hz) is identified 
by the frequency detector 332 in the output signal of the photosensor, or 
by outdoor sunlight in the absence of such particular frequency. The 
output signal of the light measuring device 330 is supplied to a CPU 301. 
A timer 304 sends information on date and time to the CPU 301, which 
identifies the current season from the date information. Like the circuit 
206 shown in FIG. 1, the CPU determines the current time by correcting the 
time difference, or determines the sunrise/sunset times, based on the 
information from an information input device 306 for preparing 
geographical information such as latitude and longitude. Said CPU is also 
connected to an exposure control device 302, a range finder unit 307 and a 
flash control device 308. Though not illustrated, shutter release switches 
SW1. SW2 are provided. as in FIG. 21, on the CPU. 
In the following there will be explained the function of the 4th 
embodiment. 
Referring to FIG. 31, when the switch SW1 is closed in response to the 
shutter releasing operation, the CPU read the geographical information in 
a step S1, then reads the date information and the time information in a 
step S2, and determines the current exact time and the sunrise/sunset 
times based on these information. Then the range finding operation and the 
light measuring operation are conducted (steps S3, S4), and the exposure 
value is determined (step S5). Then a step S6 discriminates whether the 
current time is in summer or winter and is in the daytime. If the current 
time is in the daytime in summer or winter, the frequency detector 332 
detects the frequency of light source (step S7), and the periodicity of 
the light source is discriminated (step S8). In the absence of 
periodicity, namely in the outdoor situation, the exposure value obtained 
in the above-explained step S5 is corrected to the plus side (step S9). 
The exposure correction to the overexposure side in the photographing in 
the daytime in summer or winter is to prevent the reproduction of white 
beach in summer or snow scene in winter in grayish tone. 
A next step S10 discriminates whether the measured object distance is 
within an effective range of the illuminating light of the flash unit, 
and, if not, an ordinary exposure control is conducted in response to the 
closing of the switch SW2 by the shutter releasing operation (step S11). 
Also if an indoor situation is identified in the detection of periodicity 
in the step S8, the ordinary exposure control is immediately executed and 
the photographing operation is completed. 
Also if the step S10 identifies that the object distance is within the 
effective distance, a photographing operation with flash emission is 
conducted in response to the closing of the switch SW2 (steps S12-S14). 
On the other hand, if the photographing situation is not in the daytime of 
summer or winter, the sequence proceeds from the step S6 to steps S21-S29 
shown in FIG. 32. 
At first there is discriminated whether the current time is in the twilight 
time, by comparison of the current time with the sunrise/sunset times 
determined in the step S2 shown in FIG. 31 (step S21), and, in case of 
twilight time, the frequency of the light source is detected by the 
frequency detector 332 (step S22), and the periodicity of the light source 
is discriminated (step S23). In the absence of periodicity, or in case of 
an outdoor situation, the exposure value is corrected to the minus side 
(step S24), and there is discriminated whether the object distance is 
effective for flash photographing (step S25). If the object is far, a step 
S26 executes exposure control for natural light illumination, whereby the 
twilight scene under morning or evening sunshine can be appropriately 
photographed with an exposure of underexposure side. 
On the other hand, if the step S23 identifies an indoor situation, an 
ordinary exposure control is immediately conducted in the step S26 and the 
photographing operation is completed. 
On the other hand, if the above-mentioned step S25 identifies that the 
object is close, the photographing operation is completed in steps S27-S29 
in the same manner as in the steps S12-S14 shown in FIG. 31. In this case 
the main object is subjected to an appropriate exposure by the flash 
emission, while the background beyond the reach of flash provides an 
underexposure, whereby the twilight situation can be appropriately 
reproduced. 
FIG. 33 shows a variation of the 4th embodiment, wherein same components as 
those in FIG. 30 are represented by same numbers and will not be explained 
further. 
At first there will be explained the discrimination of color temperature of 
the light source. Different light sources have different spectral 
characteristics, defined by frequency-dependent distribution of light 
intensity. Consequently the light source can be identified by comparing 
said light intensity distribution. In practice, such identification is 
possible by comparison in two wavelength regions. For this reason, there 
is employed a method of comparing the intensity in a long wavelength 
region and a short wavelength region in the visible wavelength range. For 
example the sunlight at twilight time has a high intensity in the long 
wavelength region, while the light of a fluorescent lamp has a high 
intensity in the short wavelength region. Expressed in color temperature, 
the former has a higher color temperature while the latter has a lower 
color temperature. Thus the comparison of light intensity distribution in 
these two wavelength regions at the longer and shorter wavelengths allows 
to identify the color temperature, or the kind of light source. 
As shown in FIG. 33, there are provided filters 401, 402 of different 
spectral transmissions. The filter 401 transmits the light of shorter 
wavelength side but does not transmit the light of longer wavelength side, 
while the filter 402 transmits the light of longer wavelength side but 
does not transmit the light of shorter wavelength side. The light of 
shorter wavelength transmitted by the filter 401 is condensed by a lens 
403 onto a photosensor 431, while the light of longer wavelength 
transmitted by the filter 402 is condensed onto a photosensor 432 by a 
lens 404. A discriminator 433 identifies the color temperature of the 
light source, by comparison of the output intensities of the photosensors 
431, 432. Thus an indoor or outdoor photographing situation can be 
identified respectively if a higher intensity is found in the shorter or 
longer wavelength region (respectively if the color temperature is low or 
high). 
The function of the present variation will not be explained further, as it 
is same as that shown in FIGS. 31 and 32, except for the analysis of color 
temperature of the light source by the discriminator 433 in steps S7 and 
S22. 
FIG. 34 shows another variation of the 4th embodiment, wherein same 
components as those in FIG. 30 are represented by same numbers and will 
not be explained further. An information recorder 502 shown in FIG. 34 
corresponds to the exposure control device 302 in FIG. 30. In this 
variation, the exposure correction is not conducted at the photographing 
operation by the camera. Instead, information on exposure correction, 
corresponding to the exposure correction value, is recorded by said 
information recorder 502 on a recording medium such as the photographic 
film itself, or a magnetic recording medium, provided in advance on the 
film cartridge, and said information is utilized in correcting the 
exposure at the preparation of a print from the photographic film. In this 
manner there is obtained a print subjected to exposure correction similar 
to that in FIG. 30 or 33. This structure is also employable in a recording 
system such as a still video camera, utilizing a non-photographic 
recording medium such as a magnetic disk. 
FIG. 35 shows still another variation, wherein same components as those in 
FIG. 33 are represented by same numbers and will not be explained further. 
In FIG. 35, an image luminance signal generator/recorder 602 corresponds 
to the exposure control device 302 in FIG. 33. This variation is primarily 
designed for example for a video camera rather than an ordinary camera, 
and is adapted to correct the image luminance signal instead of the 
exposure correction. 
In the case where date and time are automatically corrected in 
correspondence to a time difference on the earth by operating switches SW1 
and SW2 of the time difference correction code, as in the second 
embodiment, it is necessary for the operator to confirm that the 
correction of the time difference has been made. For example, in the case 
where only the current time but no date has been corrected by the time 
difference correction, the operator can not confirm whether the time 
difference has been corrected surely or not. 
The fifth embodiment described below, in order to obviate such an 
inconvenience, is so constructed that, when it is judged that no date is 
changed by a time difference correction, a fact that time has been 
corrected by the time difference correction may be displaced during 
predetermined time. Since the camera structure adopting the fifth 
embodiment is the same as shown in FIG. 7, only display modes and a 
control operation by a control circuit will be described. 
FIG. 36 shows a display unit L1 in the fifth embodiment comprising a 
display area 501 for displaying a time difference correction code, a 
display area 502 for displaying daylight saving time, a display area 503 
for displaying completion of data photographing, and a display area 504 
for selectively displaying a calendar information (year, month and date; 
month, date and year, or date month and year) and time (date, hour and 
minute). 
FIGS. 37 and 38 show, respectively, the state of calendar display and the 
state of time display in the case where Tokyo is selected by the time 
difference correction code. FIG. 39 shows a flow chart explaining the 
operation for changing over the display shown in FIG. 37 to that shown in 
FIG. 38. 
When the switch SW6 is operated to effect mode change, judgement is made at 
step S61 whether the current display mode is of the year-month-day mode or 
not. If the display mode is of the year-month-day mode at step S61, the 
display mode is changed at step S66 to month-day-year mode which is the 
next mode in the five kinds of the display modes, that is, year-month-day 
mode, month-day-year mode, day-month-year mode, day-hour-minute mode and 
off mode (no display mode). If the year-month-day mode is not judged at 
step S61, judgement is made at the next step S62 whether the mode is of 
the month day-year mode or not. Thus, the operation of the switch SW6 
effects change of the above mentioned five display modes through steps S61 
to S66 in this order. 
Here, it is assumed that Beijin (time difference correction code 20) having 
a time difference of 1 hour from Tokyo is selected. In this case, the 
calendar display shown in FIG. 37 changes to that shown in FIG. 40. These 
two calendar displays are the same except for the code display area 501, 
and moreover there is no time display. Accordingly, it is not possible to 
confirm the content obtained by the correcting operation and it is not 
possible to make judgement as to whether the correction has been executed 
or not. 
According to the fifth embodiment of the invention, the display mode is 
changed to a time display by a predetermined time as shown in FIG. 41, and 
thereafter the display mode is returned to a calendar display as shown in 
FIG. 40. The operation will be described with reference to the flow chart 
of FIG. 42. 
At step S71, the time difference correction code 20 of Beijin is inputted 
and at step S72 calculation and correction of the time difference 
according to the inputted correction code are effected. At step S73 
judgement is made whether the current display mode is of time display mode 
or not. If the current mode is of time display mode, the display mode is 
selected as it is. If at step S73 it is judged that the current display 
mode is not of time display mode, then at step S74 judgement is made 
whether current mode is off mode or not, thereafter at step S75 display 
mode being changed to time display mode and being effected by the 
predetermined time and then at step S76 returning to the original mode 
being effected. 
Thus, the operator can confirm that the time difference correction has been 
effected with no failure. 
FIG. 43 shows a case where Los Angeles is selected by inputting of time 
difference correction code Since it is a.m. 9:10 at Tokyo, it is p.m. 5:10 
in the previous day at Los Angeles, so numeral 8 at day display area in 
the calendar display in FIG. 37 will be changed to numeral 7 shown in FIG. 
43. In this case, it is possible to know from the change of the day 
display that time difference correction operation has been executed. In 
this example further, arrangement of the display is automatically changed 
to one which people living in that selected city uses most conventionally 
or customarily, that is from year, month and day arrangement in Tokyo to 
month, day and year arrangement in Los Angeles, thereby the operator 
advantageously realizing that the time difference correction being 
effected with no failure. 
Even in this example, the calendar display may be changed to time display 
provisionally by a predetermined time. FIG. 45 shows a flow chart of such 
a case. Steps S81 to S86 and S89 of this flow chart is the same as steps 
S71 to S77 of FIG. 42. At steps S85 time display mode is executed by the 
predetermined time, and at step SB7 it is judged whether arrangement of 
the previous calendar display is the same as the customary arrangement of 
calendar display at the city corresponding to the time difference 
correction code inputted at step S81, and if not, correction is made to 
the customary arrangement and returned to the calendar display at step 
S88. 
In FIG. 45, the time display mode may be executed only in the case where no 
day display is changed by the time difference correction. The above 
mentioned embodiments may be so constructed that in synchronization with 
start of manual operation for the time difference correction, change may 
be made to time display mode and simultaneously with the end of the 
operation returning to the calendar display mode may be effected.