Exposure control mode selection device for camera

A multi-mode automatic exposure control camera capable of permitting selective switch-over among various exposure control modes is provided with a device which displays each selected exposure mode in the form of a pictograph or the like representing a picture effect obtainable from the selected mode and which also gives a warning through the medium of the displayed pictograph or the like for the object to be photographed when the effect expected from the selected exposure control mode is difficult to obtain.

BACKGROUND OF THE INVENTION: 
1. Field of the Invention: 
This invention relates to a photographic camera of the kind permitting 
selection of one of various exposure control modes and more particularly 
to an exposure control mode selection device which gives a warning when 
the desired picture image effect corresponding to a selected exposure 
control mode is difficult obtain. 
2. Description of the Prior Art: 
As a result of recent advancement of electronic applications in 
photographic cameras, multi-mode automatic exposure control type cameras, 
which permit switch-over among various exposure control modes by a 
selecting operation on an operating member, have been in practice. In 
regard to pictographs or the like for displays made on photographic 
cameras on the other hand, cameras using pictographs of mountains or dolls 
as an indication of distance for visual distance measurement have also 
been in practice. Use of patterns for indicating flash photography has 
also been in practice. 
However, in exposure control display modes. letters or symbols have been 
used. In many of the above-stated multi-mode, automatic exposure control 
cameras, the exposure control modes are indicated by letters or symbols 
such as M (for manual), AV (for aperture preference AE), TV (for shutter 
preference AE), P (for programmed AE), etc. With this conventional 
arrangement, it is difficult to be understand what is indicated by such 
letters or symbols, particularly for beginners. Beginners are incapable of 
selecting an adequate aperture value or shutter time suitable for 
obtaining a desired picture image effect. The image effect varies with the 
focus depth and shutter time. For people who do not know the interrelation 
between an aperture value, shutter time, film sensitivity and brightness 
of an object to be photographed, the relation of a picture effect to the 
aperture value and shutter time is difficult to understand. Therefore, a 
mere indication of the exposure control mode in letters or symbols does 
not let such people readily know an appropriate combination of the shutter 
time and the aperture value required for obtaining a certain desired 
picture effect. Besides, the prior art indication can not show a 
photographing range within which an adequate picture image effect is 
obtainable. For example, with a symbol A or AV used for indicating an 
aperture preference mode, it is still unknown what the aperture value 
should be in order to obtain a pan-focus effect, which gives a photograph 
with a deep focus depth and which is obtainable by making the aperture 
smaller. It is also unknown at what range of object brightness the 
pan-focus effect can be obtained. 
To solve this problem, the present inventors have previously proposed an 
arrangement as disclosed in Japanese Utility-Model Application No. Sho 
55-154016 corresponding to U.S. patent application Ser. No. 313,504. 
According to the proposed arrangement, in order for a beginner to take a 
photograph considering the picture effect obtainable from a combination of 
aperture value and shutter time, the camera incorporates therein a program 
of combinations of aperture values and shutter time values from which 
various picture effects are derivable. Simple pictographs representative 
of picture effects obtainable in accordance with the program are shown 
within a view finder or on the surface of the camera. The simple selection 
of one of the various pictographs shown on the camera surface enables the 
photographer to take a photograph with the picture effect represented by 
the selected pictograph. 
It is an object of the invention to provide an improvement on a camera 
permitting the photographer to obtain a photograph having a desired effect 
represented by a pictograph with the pictograph selected out of various 
pictographs. The improvement gives a warning when the desired picture 
effect cannot be obtained. 
It is another object of the invention to provide an improvement on a camera 
permitting the photographer to obtain a photograph having a desired effect 
represented by a selected pictograph, the improvment displaying all 
exposure control modes selectable from various exposure control modes 
depending on the brightness of the object to be photographed. 
These and further objects and features of the invention will become 
apparent from the following detailed description of preferred embodiments 
taken in conjunction with the accompanying drawings. 
SUMMARY OF THE INVENTION 
The invention relates to a camera which permits selection of an exposure 
control mode from a plurality of exposure control modes. The camera 
includes display means for displaying the exposure control mode selected 
and the display means is displayed in a pictograph, a picture effect 
obtainable from the exposure control mode selected. The camera also 
includes light measuring means for measuring the brightness of an object 
to be photographed. The light measuring means produces an electrical 
signal corresponding to the brightness of the object. Also included are 
control means for controlling the display action of the display means. The 
control means receives the signal from the light measuring means and 
varies the display condition of the display means when the brightness of 
the object would not give the picture effect expected from the exposure 
control mode selected.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With reference to the accompanying drawings, a preferred embodiment of the 
present invention will be described as follows: FIG. 1 shows the upper 
surface of the camera. The camera includes a camera body 71; a 
photo-taking lens 72; and an external display arrangement 73 which 
displays exposure control modes. For this display, a material such as 
liquid crystal or the like, that permits electrical control over the 
transmission factor thereof, is used for the external display arrangement 
73. Included in the camera are an exposure control mode selection button 
74 which is provided for switch-over between exposure control modes; a 
light measurement button 75 operated at the time of light measurement; and 
a release button 79. The visual field of the view finder of the camera 
shown in FIG. 1 is shown in FIG. 2. Referring to FIG. 2, the view finder 
is provided with a view finder display arrangement 76 consisting of 
members made of a material such as liquid crystal that permits electrical 
control over the transmission factor thereof. The view finder display 
arrangement 75 makes displays corresponding to those of the external 
exposure control mode display arrangement 73. In other words, the external 
display arrangement 73 shown in FIG. 1 shows pictographs 73a, 73b, 73c, 
73d and 73e, as shown in FIG. 3. These pictographs 73a, 73b, 73c, 73d and 
73e respctively correspond to the pictographs 76a, 76b, 76c, 76d and 76e 
which are at the view finder display arrangement 76 shown in FIG. 2. The 
pictograph display part 73a represents an aperture preference mode in 
which the aperture of the lens 72 is decreased, deepening the focus depth. 
This aperture preference mode hereinafter will be called a pan-focus mode 
A. The pictograph display part 73b represents a shutter time preference 
mode in which a high speed shutter time is used. The shutter perference 
mode hereinafter will be called stop motion mode B. The pictograph display 
part 73c represents another shutter time preference mode in which a low 
speed shutter time is employed for non-stop motion or panning photography, 
etc. This mode hereinafter will be called a panning shot mode C. The 
pictograph display part 73d represents an aperture preference mode in 
which an aperture value on the wider opened side is used for a shallower 
focal depth. That aperture preference mode hereinafter will be called a 
graduate mode D. Furthermore, the pictograph or symbol display part 73e 
represents a standard programmed mode in which combinations of high 
aperture values and shutter time values to be frequently used are used for 
photography. This programmed mode hereinafter will be called a normal 
program mode E. 
Referring now to FIG. 4 which shows the program lines used for the 
muti-mode automatic exposure control type camera of FIG. 1, the ordinate 
of the drawing shows aperture values F (or F-numbers) and the abscissa 
shows shutter time values T. The drawing scale shows EV which corresponds 
to LV values at ASA 100. In FIG. 4, a reference symbol A indicates the 
pan-focus mode. In the pan-focus mode A, the shutter time T is 2 and the 
aperture value F is 2 to 22 within the range of EV values from 1 to 8; and 
the shutter time T is 2 to 1/1000 sec. The aperture value F is 22 within 
the range of EV values from 8 to 19. The symbol B indicates the stop 
motion mode in which the shutter time T is 2 to 1/1000 sec. and the 
aperture value F is 2 within the range of EV=1-12 while, the shutter time 
is 1/1000 sec. and the aperture value F is 2 to 22 within the range of 
EV=12-19. The symbol C indicates the panning shot mode, in which the 
shutter time T=2-1/15 and the aperture value F=2 within the range of 
EV=1-6; the shutter time T=1/15 sec. and the aperture value F=2-22 within 
the range of EV=6-13; and the shutter time T=1/15-1/1000 sec. and the 
aperture value F=22 within the range of EV=13-19. A symbol D indicates the 
graduate mode, the diagram of which is identical with that of the stop 
motion mode B. Another symbol E indicates the normal program mode, in 
which the aperture value is F=2 and is constant (for EV=1-5) within the 
range of the shutter time T=2-1/8 sec. On the higher brightness side of 
the normal program mode E, there are combinations of the aperture value 
and the shutter time value as representated by a line connecting the point 
of the aperture value F=2 and the shutter time T=1/8 sec. to a point of 
the aperture value F=22 and the shutter time T=1/1000 sec. In this 
specific embodiment, the shutter time values and the aperture values are 
programmed within the following ranges, which are considered to give 
various picture effects: 
______________________________________ 
A (pan-focus mode): 
EV = 13-19, shutter value F = 22 
B (stop motion mode): 
EV = 11-19, shutter time 
T = 1/500-1/1000 sec. 
C (panning shot mode): 
EV = 5-14, shutter time 
T = 1/8-1/30 sec. 
D (gradate mode): 
EV = 6-13, aperture value 
F = 2-2.8 
E (normal mode): 
EV = 1-19 
______________________________________ 
With the camera programmed as shown above, the camera photography 
operations is as follows in cases where, for example the lens 72 of a 
maximum aperture F=2 and a minimum aperture F=22 is mounted on the camera 
using a film of sensitivity ASA 100, the focal length of the lens 72 being 
50 mm or thereabout: When the main switch which is not shown is turned on, 
the pictograph display parts 73e and 76e respectively appear at the 
exposure control mode display arrangement 73 and the view finder display 
arrangement 76. Then, when the above exposure control mode selection 
button 74 is depressed once, the pictography display parts 73a and 76a 
appear respectively at the exposure control mode display arrangement 73 
and the view finder display arrangement 76. The pictograph display parts 
73e and 76e disappear indicating that the exposure control mode has been 
switched over from the normal program mode to the pan-focus mode. Then 
when the exposure control mode selection button 74 is depressed again, the 
pictograph display parts 73a and 76a disappear while the pictograph 
display parts 73b and 76b appear to show the switch-over from the 
pan-focus mode A to the stop motion mode B. Subsequent depressing 
operations likewise on the exposure control mode selection button 74 then 
result in shifting of the exposure control mode to the panning shot mode 
C, graduate mode D and the normal program mode E one after another with 
the pictograph display parts 73c, 73d, 73e, 76c, 76d and 76e appearing at 
the exposure control mode display arrangement 73 and the view finder 
display arrangement 76 showing the exposure control modes one after 
another. Furthermore, the embodiment may also be such that the exposure 
control mode, the external exposure control mode display and the view 
finder display are switched over one after another as the exposure control 
mode selection button is kept depressed. 
Photography in the pan-focus mode A is as follows: The control circuit is 
set in the pan-focus mode A with the exposure control mode selection 
button 74 depressed as has been described above. The pictograph display 
part 76a is displayed at the view finder display as shown in FIG. 5. In 
the case of object's brightness EV=16, the aperture value and the shutter 
time value are respectively set at F=22 and T=1/250 sec. A photograph 
having an adequate exposure and a pan-focus effect can be obtained with 
the shutter of the camera released under this condition. However, when the 
object's brightness is either less than EV=12 or above EV=20, the 
condition deviates from the range of the effect of the program line part 
A. In that case, the exposure control mode display part 73a and the view 
finder display part 76a flicker informing the photographer that it is 
impossible to take a photograph having the pan-focus effect. The condition 
of the view finder display part 76a at that time is shown in FIG. 6. 
An operation in the stop motion mode B is as follows: The camera is set in 
the stop motion mode B by depressing the exposure control mode selection 
button 74 as described in the foregoing. The pictograph display parts 73b 
and 76b are displayed respectively at the external exposure control mode 
display arrangement 73 and the view finder display arrangement 76 
indicating that the camera is set in the stop motion mode B. When the 
photographing object's brightness is EV=15, the shutter time is set at 
1/1000 sec. and the aperture value at F=5.6 Shutter release under this 
condition gives a photograph having an appropriate exposure and the effect 
of the stop motion mode B. However, if the object's brightness is less 
than EV=10 or exceeds EV=20, the above condition is out of range of the 
effect of the program line part B. Therefore, the exposure control mode 
display part 73b and the view finder display part 76b flicker informing 
the photographer that it is impossible to take a photograph with the 
desired stop motion effect. Operations in the panning shot mode C and in 
the graduate mode D are similar to this. In these modes, the display parts 
73c and 73d are displayed at the exposure control mode display arrangement 
73 and the display parts 76c and 76d at the view finder display 
arrangement 76 respectively with the modes being set by depressing the 
exposure control mode selection button 74. Deviation from the effect of 
the program line part C or D then takes place for an object's brightness 
below EV=4 and above EV=15 in the panning shot mode C and for an object's 
brightness below EV=6 and above EV=15 in the gradate mode D. In such a 
situation the exposure control mode display parts 73c and 73d and the view 
finder display parts 76c and 76d respectively flicker informing the 
photographer that no photograph having the effects expected from these 
modes can be taken. 
The above program lines for the exposure control modes are given by way of 
example. The expected picture effect is not always warranted 100 percent 
due to differences in the moving speed of the object, distance between a 
main object and the background thereof and the focal length of the lens 72 
in use. In the case of the stop motion mode B, for example, the expected 
stop motion picture effect is not obtainable unless a high speed shutter 
time above 1/500 sec. is used for a high speed object such as a ski 
contest or a car race, while the stop motion effect can be sufficiently 
obtained at a shutter time value of 1/250 sec. or thereabouts for a 
running race of little children. It is difficult for a beginner to select 
the most suitable aperture value and shutter time in relation to the 
object to be photographed and the focal length of the lens 72. Therefore, 
it is necessary that an aperture value and a shutter time value that are 
most suited for obtaining the expected picture effect are combined to 
lessen the probability of failure in photographing many different objects 
even by a beginner. Furthermore, it is also possible to divide the same 
exposure control mode into two parts and to program each part different 
from the other. For example, in the stop motion mode B, the mode B is 
divided into two to program a shutter preference mode having a shutter 
time of 1/500 to 1/1000 sec. for the first divided part 73b1 and a shutter 
preference mode having a shutter time of 1/250 sec. for the other divided 
part 73b2, as shown in FIG. 7. Each of the other modes can also be divided 
in the same manner. 
In the example given above, the lens 72 of a maximum aperture value of F=2 
and a minimum aperture valve of F=22 is used. In cases where the lens 72 
of a maximum aperture value is F=4 or F=5.6 and a minimum aperture value 
is F=16 or F=11, the camera which is arranged as in the foregoing does not 
operate satisfactorily because the program lines are fixed in the camera. 
It is possible, however, to set the program line part A for the minimum 
aperture value of the lens 72 to be used or to set the program line part D 
for the maximum aperture value thereof. 
Next, when the light measurement button 75 is depressed, light measurement 
is carried out by means of a light sensitive element which is not shown 
but is provided inside the camera. Then, the exposure control mode display 
parts 73a, 73b, 73c, 73d and 73e and the view finder display parts 76a, 
76b, 76c, 76d and 76e appear and all display modes other than the modes 
that are within an automatic exposure control range flicker according to 
the brightness of the object to be photographed, as shown in Table 1. This 
informs the photographer of the mode in which photography can be 
accomplished. 
TABLE 1 
______________________________________ 
EV Exposure control mode 
View finder display 
values display parts that flicker 
parts that flicker 
______________________________________ 
Below 1 
73a; 73b; 73c; 73d and 73e 
76a; 76b, 76c; 76d and 76e 
1-4 73a; 73b; 73c and 73d 
76a; 76b; 76c and 76d 
5 73a; 73b and 73d 
76a; 76b and 76d 
6-10 73a and 73b 76a and 76b 
11-12 73a 76a 
13 
14 73d 76d 
15-19 73c and 73d 76c and 76d 
Above 20 
73a; 73b; 73c; 73d and 73e 
76a; 76b; 76c; 76d and 76e 
______________________________________ 
In the specific embodiment which has been described above, the flickering 
actions of the pictograph display parts indicate the modes in which no 
photograph having the expected picture image effect can be taken when the 
light measurement button is depressed. However, conversely the flickering 
may indicate solely the modes in which photographs can be taken with the 
expected effects when the light measurement button 75 is depressed. 
Referring now to FIG. 9 which shows the control circuit arrangement of the 
camera shown in FIG. 1, a constant voltage source 1 supplies a bias 
voltage to the non-inversion input terminal of each of the operational 
amplifiers 3 and 8. The circuit arrangement includes a constant current 
source 2; the operational amplifiers 3, 5 and 8 (hereinafter each of 
operational amplifiers will be called OP amp for short); diode 4 for 
temperature compensation; a photo diode 6 which produces a photo current 
in proportion to the brightness of the object to be photographed; a diode 
7 for logarithmic suppression; a posistor 9; an SV information resistor 10 
supplying information proportional to the sensitivity of the film in use; 
an AVO information resistor 11 supplying information on the minimum 
aperture F value (full aperture) of the lens 72 mounted on the camera 
body; a resistor 12 for a known light measurement circuit which is formed 
jointly by these elements 1-12; a pulse generator 13 produces reference 
pulses; an A/D converter 14 converts an analog voltage received at the 
terminal A thereof into a digital value of 5 bits D0-D4; and an A/D memory 
circuit 15 receives at its terminals A0-A4 the digital value produced from 
the A/D converter 14 and produces memory values corresponding to the 
terminals A0-A4 to its terminals B0-B4. Upon completion of every 
analog-to-digital converting action, the output of the A/D converter 14 is 
transferred to the A/D memory circuit 15 to renew the memory value of the 
memory circuit 15. The terminals B0-B4 of the memory circuit 15 are 
connected to the terminals C0-C4 of a decoder 16 of 5 bits. One of the 
output terminals Q0-Q20 of the decoder 16 is selected according to the 
digital value. Since the input to the decoder 16 is 5 bits, there exist 32 
bits. However, for the reason which will be described later herein, higher 
11 bits are not used. 
A control mode change-over switch 17 operates in response to the operation 
of the mode selection button 74, which is shown in FIG. 1. A one shot 
multivibrator 18 is connected to an OR gate 20 and produces a pulse from 
the output terminal thereof when the switch 17 is turned on. A counter 19 
receives at its terminal CLK the reference pulses from the pulse generator 
13. When a prescribed number of pulses have been counted, the level of the 
terminal Q of the counter 19 changes from a low level (hereinafter called 
an L level) to a high level (hereinafter called an H level). The switch 17 
is connected to reset terminal R of the counter 19. The counting action of 
the counter 19 is not performed when the switch 17 is off and is performed 
when the switch 17 is turned on. The output of the OR gate 20 is impressed 
on the terminals CLK of D type flip-flops 21-25. Terminals D and Q of each 
of these flip-flops 21-25 are input and output terminals. When, the H 
level input is impressed on preset terminal P of the flip-flop 21, the 
level of the terminal Q becomes an H level. When the H level inputs are 
impressed on clear terminal C of the flip-flops 22-25, the levels of the 
terminals Q of these flip-flops become 22-25 L levels. A power on clear 
circuit 26 produces pulses the level of which becomes high for a short 
period of time when the output of a camera power source, which is not 
shown, is impressed on the circuit 26. The pulses produced from the power 
on the clear circuit 26 are impressed on the terminal P of the flip-flop 
21 and the terminals C of the flip-flops 22-25. A counter 27 has the 
reference pulses from the pulse generator 13 impressed on the terminal CLK 
thereof in the same manner as the counter 19. The level of the terminal Q 
of the counter 27 changes from an L level to an H level after a prescribed 
number of the reference pulses have been counted. An OR gate 28 receives 
the outputs Q0 and Q20 of the decoder 16. The control circuit arrangement 
further includes AND gates 29 and 30; an inverter 31; an OR gate 32; a 
drive circuit 33 which drives the display parts 76e of FIG. 2, 73e of FIG. 
3 and 78e of FIG. 8 and has its output terminal connected to these display 
parts; an OR gate 34 which receives the outputs Q13-Q19 of the decoder 16; 
AND gates 35 and 36; an inverter 37; an OR gate 38; a drive circuit 39 the 
output terminals of which are connected to the display parts 76a of FIG. 
2, 73a of FIG. 3 and 78a of FIG. 8 and thus drive these display parts; an 
OR gate 40 receives the outputs Q11-Q19 of the decoder 16; AND gates 41 
and 42; an inverter 43; an OR gate 44; a drive circuit 45 which has its 
output terminal connected to the display parts 76b of FIG. 2, 73b of FIG. 
3 and 78b of FIG. 8 to drive them; an OR gate 46 which receives the 
outputs Q5-Q14 of the decoder 16; AND gates 47 and 48; an inverter 49; an 
OR gate 50; a drive circuit 51 which has its output terminal connected to 
the display parts 76c of FIG. 2, 73c of FIG. 3 and 78c of FIG. 8 and which 
drives them; and OR gate 52 which receives the outputs Q6-Q13 of the 
decoder 16; AND gates 53 and 54; an inverter 55; an OR gate 56; a drive 
circuit 57 which has its output terminal connected to the display parts 
76d of FIG. 2, 73d of FIG. 3 and 78d of FIG. 8 and thus drives them; and 
program line selection circuits 58-62. One of the program lines for the 
modes A-E shown in FIG. 4 is selected by the selection circuits 58-62. The 
shutter speed T and the aperture value F are determined by the output of 
the OP amp 8 on the line. The circuit 58 selects the program line of the 
normal mode E of FIG. 4; the circuit 59 selects the program line of the 
pan-focus mode A; the circuit 60 selects the program line of the mode 
stop-motion B; the circuit 61 selects the program line of the panning shot 
mode C; and the circuit 62 selects the program line of the gradate mode D 
of FIG. 4. A light measurement switch 63 has one terminal thereof 
connected to a power source VDD. When the light measurement switch 63 
turns on in response to depressing the light measurement button 75, a 
power source switch, which is not shown also turns on to supply power to 
each applicable part. OR gates are identified by reference numerals 64-68. 
One of the input terminals of each of these OR gates 64-68 is connected to 
the other terminal of the light measurement switch, which is not connected 
to the power source. 
Furthermore, referring to FIG. 8, a warning for the exposure control mode 
may be given by flickering lamps 78a-78e such as LED's which correspond to 
the pictographs 77a-77e shown in FIG. 8. 
The embodiment which is arranged as above operates in the following manner: 
The light measurement circuit, which consists of the elements 1-12 and is 
arranged in a known manner, does not require detailed description thereof. 
First, a photo current which corresponds to the brightness of the object 
to be photographed flows through the photo diode 6. The photo current is 
logarithmically suppressed by the OP amp 5 and the logarithmic suppression 
diode 7. Furthermore, the output of the temperature compensation circuit 
which is composed of the constant current circuit 2, the diode 4 and the 
OP amp 3 is impressed on the non-inversion input terminal of the OP amp 5 
to offset the saturation currents in the suppressing direction of the 
diodes 4 and 7, which have the same characteristics. Accordingly, the 
output of the OP amp 5 logarithmically suppresses the object's brightness 
and also has a voltage proportional to the absolute temperature. This 
voltage is processed through the posistor 9, the resistor 12 and the OP 
amp 8 to make the output of the OP amp 8 into a logarithmically suppressed 
value that is independent from the temperature of the object's brightness. 
Then, the SV information resistor 10 and the AVO information resistor 11 
respectively supply the film sensitivity information and the maximum F 
value information of the lens 72 to further make the output of the OP amp 
8 into a voltage corresponding to an exposure light quantity EV. However, 
the light measurement range is from EV 0 to EV 20. The voltage thus 
obtained is impressed on the terminal A of the A/D converter 14 which uses 
the output of the pulse generator 13 as reference pulses. The A/D 
converter 14 then (analog-to-digital) converts the voltage and produces 
the digital value thereof at the terminals D0-D4. In other words, the 
digital value produced at the terminals D0-D4 of the A/D converter 14 
corresponds to the value EV. The digital value is transferred to the 
terminals A0-A4 of the A/D memory circuit 15 every time the A/D converter 
14 completes an A/D converting action. The digital value is thus stored 
and kept at the memory circuit 15. The stored value is produced from the 
terminals B0-B4 of the A/D memory circuit 15 and is impressed on the 
terminals C0-C4 of the decoder 16. The decoder 16 decodes the binary code 
of the terminals C0-C4 thereof and produces outputs Q0-Q20. In this 
instance, since the light measurement range is from brightness EV 0 to 
brightness EV 20 as mentioned in the foregoing, other outputs Q21-Q31 of 
the decoder 16 remain unused and are thus omitted from the illustration. 
Furthermore, the outputs Q0-Q20 respectively correspond to the values EV 
0-EV 20. 
When the power supply of the camera is turned on by a switch which is not 
shown, the power on the clear circuit 26 produces an H level pulse for a 
short period of time and is impressed on the terminal P of the D type 
flip-flop 21 and the terminals C of the D type flip-flops 22-25. This 
results in an H level output Q of the D type flip-flop 21 and L level 
outputs Q of the D type flip-flops 22 and 25. This condition remains 
unchanged unless the switch 17 is turned on. When the switch 17 which 
corresponds to the switch 4 shown in FIG. 1 is once operated on and off, 
the one-shot multivibrator 18 produces a one-shot pulse, which is supplied 
via the OR gate 20 to the terminals CLK of the D type flip-flop group 
21-25. Then, in synchronization with the pulse rise, the output Q of the D 
type flip-flop 21 becomes an L level and the output Q of the D type 
flip-flop 22 an H level while the outputs Q of the rest of the D type 
flip-flop group 23-25 remain at the L level. In other words, the H level 
of the output Q of the flip-flop 21 is moved to the output Q of the 
flip-flop 22. Furthermore, if the switch 17 is once again turned on and 
off, the one-shot multivibrator 18 likewise produces another one-shot 
pulse causing the H level of the output Q of the D type flip-flop 22 to 
move to the output Q of the D type flip-flop 23. Following this, every 
time the switch 17 turns on, the sole H level of one of the outputs Q of 
the D type flip-flop group 21-25 shifts from one flip-flop to another 
toward the flip-flop 25 and then from the flip-flop 25 back to the first 
flip-flop 21 repeating the same process. Since the reset terminal R of the 
counter 19 is connected to the switch 17, the counter 19 is in a reset 
condition and its output Q remains at an L level when the switch 17 is 
off. When the switch 17 is once turned on and then is quickly turned off, 
the counter 19 might begin to count according to the reference pulses from 
the pulse generator 13. However, since the counter 19 is reset before the 
output Q level thereof becomes high, the output Q level of the counter 19 
remains low in the same manner as when the switch 17 remains off. However, 
if the switch 17 is allowed to be continuously on over a period exceeding 
a predetermined length of time, the counter 19 performs a counting action 
and its output Q repeats alternately becoming H and L levels in a 
prescribed cycle. Since the output Q of the counter 19 is impressed via 
the OR gate 20 on the terminals CLK of the D type flip-flop group 21-25, 
the H level of the output Q of the D type flip-flop 21 at the beginning of 
the power supply shifts to other D type flip-flops in such a manner as 
22.fwdarw.23.fwdarw.24.fwdarw.25.fwdarw.21.fwdarw. . . . one after another 
at fixed time intervals, as mentioned in the foregoing. Furthermore, when 
the switch 17 turns off after it has been continuously on, the counter 19 
is reset. Then, the output Q of one of the D type flip-flops 21-25, which 
is at an H level when the switch 17 turns off, remains at the H level. 
When the power supply is turned on, since at that time the output Q of the 
D type flip-flop 21 among the group 21-25 is solely in an H level, the 
program line selection circuit 58 to which the output terminal Q of the 
flip-flop 21 is connected is selected. With the program line selection 
circuit 58 thus selected, the shutter speed or time T and the aperture 
value F of the F-number are determined on a program line part E of FIG. 4 
according to the value EV, i.e. the output of the OP amp 8. If the valve 
EV is then between 1 and 19, the decoder 16 selects one of the outputs 
Q1-Q19. Therefore, the output of the OR gate 28 is at the L level and 
accordingly the output of the inverter 31 becomes the H. Accordingly, the 
output of the AND gate 29 becomes L and that of the AND gate becomes H 
actuating the drive circuit 33 through the OR gate 32. With the drive 
circuit 33 thus actuated, the display parts 76e of FIG. 2 and 73e of FIG. 
3 or 78 e of FIG. 8 light up indicating the program mode selected. When 
the value EV is either 0 or 20, that is, if it deviates from the program 
line part E of FIG. 4, the decoder 16 produces the output Q0 or Q20. This 
causes the output level of the OR gate 28 to become high and that of the 
AND gate 30 to become low through the inverter 31. Meanwhile, since the 
reference pulses from the pulse generator 13 are impressed on the terminal 
CLK of the counter 27, the output of the counter 27 repeats, alternating 
between H and L levels. The output Q of the counter 27 is impressed on one 
of the input terminals of the AND gate 29. Therefore, the wave form of the 
AND gate 29 output becomes the same as that of the output Q of the counter 
27. This signal is further impressed via the OR gate 32 on the drive 
circuit 33. This causes the display parts 76e of FIG. 2 and 73e of FIG. 3 
or 78e of FIG. 8 to flicker, warning the camera operator that no 
appropriate photograph can be taken although the program line part E of 
FIG. 4 is selected. 
When the switch 17 which corresponds to the switch 74 of FIG. 1 is allowed 
to be one for a short period, the output Q of the D type flip-flop 22 
among the D type flip-flop group 21-25 alone becomes an H level, as has 
been described in the foregoing. This high level output causes the program 
line selection circuit 59 to select the program line part A of FIG. 4. In 
this instance, if the value EV is between 13 and 19, the output level of 
the OR gate 34 becomes H. The level of the AND gate 35 also becomes H. The 
H level output causes the drive circuit 39 to operate via the OR gate 38. 
With the drive circuit 39 thus operating, the display parts 76a of FIG. 2 
and 73a of FIG. 3 or 78a of FIG. 8 light up informing the camera operator 
of the selection of the program line part A of FIG. 4. Furthermore, when 
the value EV is not within the range of 13 to 19, the output of the OR 
gate 34 becomes an L level, that of the inverter 37 an H level and that of 
the AND gate 36 the same wave form as the output Q of the counter 27. The 
signal thus obtained is transferred via the OR gate 38 to the drive 
circuit 39. The drive circuit 39 then causes the display parts 76a of FIG. 
2 and 73a of FIG. 3 or 78a of FIG. 8 to flicker. Then, in the same manner 
as described above, the program line selection circuit 60 operates when 
the switch 17 is again on for a short period and by this the program line 
part B of FIG. 4 is selected. If the value EV is within the range of 11 to 
19 at that instant, the display parts 76b of FIG. 2 and 73b of FIG. 3 or 
78b of FIG. 8 light up. However, they flicker if the value EV is not 
within the range of 11 to 19. Then, when the switch 17 is again turned on 
for a short period, the program line selection circuit 61 selects the 
program line part C of FIG. 4. In that situation, if the value EV is 
within the range of 5 to 14, the display parts 76c of FIG. 2 and 73c of 
FIG. 3 or 78c of FIG. 8 light up. If the value EV is outside the above 
range, they flicker. When the switch 17 is again turned on for a short 
period, the program line selection circuit 62 selects the program line 
part D of FIG. 4. Then, the display parts 76d of FIG. 2 and 73d of FIG. 3 
or 78d of FIG. 8 light up if the value EV is within the range of 6 to 13 
or flicker if the value EV is outside the range. Then, if the switch 17 is 
once again turned on for a short period, the program line selection 
circuit 58 is selected once more and the embodiment goes back to the 
initial power supply condition. 
In the above-described instances, the switch 17 is turned on for a brief 
period of time. If the switch 17 is continuously on, the H level of the 
output Q among the flip-flop group 21-25 shifts from one flip-flop to 
another in such a manner as 
21.fwdarw.22.fwdarw.23.fwdarw.24.fwdarw.25.fwdarw.21.fwdarw. . . . as has 
been described in the foregoing. The program line selection circuits 58-62 
and the lighting-up and flickering displays are also switched over from 
one to another depending on the value EV. Meanwhile, the selection of the 
display drive circuits 33-57 also continues to change. The display parts 
76a-76e of FIG. 2 and the display parts 73a-73e of FIG. 3 or the display 
parts 78a-78e of FIG. 8, which are connected to these display drive 
circuits, are thus operated one after another. When the camera operator 
selects one of the program lines while watching the displays, if the 
switch 17 is turned off when the display parts for the desired program 
line lights up or flickers, the camera is then stopped in the desired 
program line condition and an exposure can be accomplished at the shutter 
speed or time T and the aperture value F or F-number depending on the 
value EV. 
When the light measurement button 75 of FIG. 1 is depressed, the light 
measurement switch 63 turns on and at the same time a power supply switch, 
which is not shown, also turns on to supply power to applicable parts of 
the camera. With the switch 63 turned on, the outputs of the OR gates 
64-68 become H levels. If at that instant, the exposure light value EV is 
12, for example, the output Q12 of the decoder 16 alone becomes an H level 
among other outputs of the decoder 16. Therefore, the outputs of the OR 
gates 28 and 34 become L levels and those of the OR gates 40, 46 and 52 
become H levels. Regarding the display conditions of the display parts 76e 
of FIG. 2 and 73e of FIG. 3 or 78e of FIG. 8, the outputs of the AND gate 
30 and the OR gate 32 become H levels as the output level of the inverter 
31 is high; the signal thus obtained is then impressed on the drive 
circuit 33 to light up the display parts 76e and 73e or 78e and thus 
informs the camera operator that an appropriate photograph can be taken 
with the program line part E of FIG. 4. As for the display condition of 
the display parts 76a of FIG. 2 and 73a of FIG. 3 or 78a of FIG. 8, the 
output of the inverter 37 becomes H while, since the reference pulses from 
the pulse generator 13 are impressed on the terminals CLK of the counter 
27, the output Q of the counter 27 repeats alternately becoming H and L 
levels in a prescribed cycle. Therefore, the wave form of the outputs of 
the AND gate 36 and the OR gate 38 are the same as that of the output Q of 
the counter 27. With this output of the OR gate 38 impressed on the drive 
circuit 39, the display arrangements 76a and 73a or 78a flicker warning 
the camera operator that no appropriate photograph can be taken when the 
program line part A of FIG. 4 is selected. In the case of the display 
parts 76b and 73b or 78b, the output levels of the AND gate 42 and the OR 
gate 44 become H. The signal thus obtained is impressed on the drive 
circuit 45 lighting up the display parts 76b and 73b or 78b. With regard 
to the display parts 76c and 73c or 78c, the levels of the AND gate 47 and 
OR gate 50 become H and the signal thus obtained is impressed on the drive 
circuit 51 lighting up the display parts 76c and 73c or 78c. As for the 
display parts 76d and 73d or 78d, the output levels of the AND gate 53 and 
OR gate 56 become H. The signal thus obtained from the OR gate 56 is 
impressed on the drive circuit 57 to also light up the display parts 76d 
and 73d or 78d. In short, among the display parts of FIGS. 2, 3 and 8, 
only the display parts 76a, 73a and 78a flicker while all other display 
parts light up. This effectively informs the camera operator beforehand 
that appropriate photographs can be taken with the use of any of the 
program line parts B, C, D and E of FIG. 4 with the exception of the 
program line part A. While the above description has covered an instance 
wherein the value EV is 12, the display conditions for other EV values are 
shown in Table 1. 
FIGS. 10 and 11 show another embodiment of the invention wherein the view 
finder display parts of FIG. 2 and the circuit arrangement thereof are 
simplified. In this situation, the display parts 76a-76e of FIG. 2 are 
consolidated into one display device 100, which gives all the warnings 
mentioned in the foregoing. Referring to FIG. 11, the circuit arrangement 
includes an OR gate 102 which is connected to the OR gate 28 and the 
inverters 37, 43, 49 and 55 of FIG. 9; an inverter 103; an AND gate 104; 
an OR gate 105; the counter 27 which is also shown in FIG. 9; and a drive 
circuit 101 which has its output terminal connected to the display device 
100 and thus drives the display device 100. The simplified arrangement, 
which accomplishes the functions of the display parts 76a-76e singly by 
means of the display device 100, is not only advantageous in terms of cost 
and space but also obviates the complication of the view finder. 
Furthermore, in FIG. 9, the high level output of the flip-flop group 21-25 
is shifted every time the switch 17 is depressed once. This arrangement 
involves the provision of circuits 17, 18, 19 and 20. However, the 
arrangement may be replaced with another arrangement shown in FIG. 12. 
Then, this modification permits utilization of the external display parts 
76a', 76b', 76c', 76d' and 76e' also as operation buttons, as shown in 
FIG. 13. More specifically, in this case, the D type flip-flops 21-25 are 
replaced with SR type flip-flops 21'-25'. The set terminals S of the 
flip-flops 21'-25' are connected to connection points between switches 
17.sub.1, 17.sub.2, 17.sub.3, 17.sub.4 and 17.sub.5 and resistors R1, R2, 
R3, R4 and R5. The flip-flop 21' alone has an OR gate OR1 inserted for its 
set terminal S. The OR gate OR1 has the power up clear circuit 26 
connected to the input terminal thereof. The connection points between the 
switches 17.sub.2, 17.sub.3, 17.sub.4 and 17.sub.5 and the resistors R2, 
R3, R4 and R5 and the OR gate OR1 are connected to a monostable 
multivibrator M through an OR gate OR2. The output terminal of this 
monostable multivibrator M is connected to the reset terminals R of the 
flip-flops 21' -25'. Furthermore, the monostable multivibrator M produces 
pulses the duration of which are sufficiently shorter than the length of 
time during which the switches 17.sub.1, 17.sub.2, 17.sub.3, 17.sub.4 and 
17.sub.5 are depressed. 
When the power up clear circuit 26 produces the pulse, the pulse is applied 
to the reset terminals R of the flip-flops 21'-25' through the OR gates 
OR1 and OR2 and the monostable multivibrator M. These flip-flops 21'-25' 
are thus reset by the pulse. Meanwhile, since the duration of the pulse 
from the monostable multivibrator M is sufficiently short, the flip-flop 
21' is alone set by the pulse of the power up clear circuit 26. When the 
operation button-and-display element 76c' is operated, the switch 17.sub.3 
is closed producing the pulse of the monostable multivibrator M, thereby 
resetting the flip-flops 21'-25'. Since the duration pulse of the 
monostable multivibrator M pulse is sufficiently shorter than the length 
of time required for closing the switch 17.sub.3, the flip-flop 23' is 
instantaneously set. Other details of operation are identical with those 
of the embodiment shown in FIG. 9 and, therefore, do not require further 
description here. 
In accordance with the present invention, as has been described previously, 
the picture effects obtainable from different exposure control modes are 
displayed by means of pictographs, so that an exposure mode for a desired 
picture effect can be readily selected. Furthermore, the pictographs 
representative of picture effects are displayed both inside and outside 
the view finder. In situations where the selected exposure control mode 
would result in a picture effect contrary to that which is desired by the 
photographer, the photographer is warned by the flickering display of the 
corresponding pictograph. Therefore, even a beginner is able to take a 
photograph using the correct exposure for a desired picture effect. The 
invention thus eliminates the possibilities of incorrect exposure and an 
undesirable picture effect. 
Furthermore, in accordance with the invention, the pictograph, 
representative of an exposure control mode in which adequate photography 
is impossible due to the brightness of the object to be photographed, is a 
flickering display informing the photographer of the improper exposure 
control mode. This is a great advantage of the present invention.