JPS5934288B2 - TTL Sotsukou Ichigun Reflex Camera Niokeru - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention sets the shutter speed preferentially, automatically controls the diaphragm aperture that provides appropriate exposure in response to this, and The present invention relates to a multi-exposure automatic control type camera that measures the light rays from a subject and controls the shutter speed according to the intensity of the light rays.

In general, when the shutter speed is prioritized and the aperture aperture is controlled according to the brightness of the subject, it is possible to automatically control the aperture aperture to give the appropriate exposure depending on the brightness of the subject. and uncontrollable cases occur.

In contrast, in the multi-exposure automatic control camera according to the present invention as described above, (a) the aperture aperture that provides appropriate exposure for a preset shutter speed is set when the brightness of the subject is controllable; The shutter speed is automatically controlled in accordance with the intensity of the subject light beam passing through the automatically controlled aperture.

In this case, the automatically controlled shutter speed is approximately equal to the preset shutter speed.

(b) If the subject is too bright for the preset shutter speed and it is not possible to obtain the proper exposure even if you control the aperture to the minimum aperture, first set the aperture to the minimum aperture for the preset shutter speed. The shutter speed is automatically controlled according to the brightness of the subject light that passes through the minimum aperture controlled above. In this case, the shutter speed to be controlled is It will be faster than the speed.

(c) If the subject is too dark for the preset shutter speed and proper exposure cannot be obtained even if the aperture is set wide open, first automatically control the aperture wide open for the preset shutter speed, The shutter speed is automatically controlled according to the brightness of the subject light beam passing through the controlled open aperture; in this case, the controlled shutter speed is slower than the preset shutter speed.

Among the above three modes of exposure control, one mode is performed depending on the brightness of the subject and the set shutter speed, but for those who operate the photography,
Before starting exposure, it is necessary to know which mode of exposure control will actually be performed. In response to the above-mentioned needs, the present invention provides an exposure display device for a TTL photometric single-lens reflex camera that notifies the photographer of which of the controllable exposure control modes is to be performed by using the flashing state of a lamp or the like prior to exposure. It is something that the goal is to obtain. An embodiment of the present invention will be described below with reference to the drawings. The maximum aperture value Fl. The exposure operation of a single-lens reflex camera according to the present invention will be explained with reference to FIG. 1, taking as an example a lens equipped with a lens that is stopped down to the minimum aperture diameter Fl6 at 4. The set shutter speed (vertical axis) as shown in the figure. For one second, the aperture aperture (horizontal axis) can be changed from the maximum aperture to the minimum aperture, Fl6, corresponding to a subject of arbitrary brightness from EV value 6 to 13, as shown by the diagonal line 30°. This value is automatically determined (in the case of (a) above).

However, there is no appropriate diaphragm aperture for brightness below E6 or above El3.

Therefore, in such a case, for example, in the case of EV5, if the aperture is fully opened Fl. 4.
11 The speed is automatically changed and controlled from 1 second to 1 second (case (c) above).

Furthermore, in the case of EVl3 or more, the aperture is similarly controlled to the minimum aperture diameter, and the shutter speed is 1.
Control is performed faster than 30 seconds (case (b) above).

In the case of (a) above, in a camera that performs such an exposure operation, the aperture aperture is automatically determined at a preset shutter speed without controlling the shutter speed to change in accordance with the exposure value. To do the above (
In the case of (b) when the shutter speed is changed to a higher speed than the preset shutter speed, only the green lamp is lit to indicate this, and vice versa. In the case (c) in which the shutter speed is lower than the set shutter speed, only a red lamp is lit to indicate this. FIG. 2 shows an embodiment of the circuit that performs the above display. The light receiving element PD receives the light ray (BV) of the subject passing through the photographing lens and the aperture. Q2 is an NPN transistor for logarithmically compressing the photocurrent of the photodetector PD, and the photocurrent flows from the emitter to the collector of transistor Q2, and the photocurrent is A voltage proportional to the value is produced across the pace emitter of transistor Q2.

The variable resistors PMl and PM2, which are connected in parallel, respectively determine the film sensitivity (S) and the preset aperture information (
This is a potentiometer for setting and introducing AV○, and a constant current is supplied by a constant current circuit 11.

The amplifier circuit AO and the transistor Q1 are high input impedance amplifier circuits, and the input PO is the transistor Q1,
Negative feedback is applied by a feedback circuit consisting of a potentiometer PMl and the emitter of a transistor Q2, and the voltage across the terminals of the photodiode PD is maintained at a constant voltage of approximately 0 volts during photometry.

Transistor Q2 in the photometric section having the above configuration
The first voltage signal is a voltage proportional to the logarithm of the brightness of the subject that has passed through the photographing lens and the aperture that appears between the emitter and the base of the film between points P7 and P8. The voltage obtained by adding the voltage according to the sensitivity, that is,
The voltage between point P8 and the ground point is defined as a second voltage signal.

Furthermore, the voltage obtained by subtracting the voltage between points P8 and P9 corresponding to the preset aperture amount from the second voltage signal is set as a third signal voltage. The voltage comparison circuits Al and A2 are both configured using differential amplifier circuits, and when the potential of the negative input terminals P2 and P4 is lower than that of the respective positive input terminals Pl and P3, the respective output terminals P5 and The potential of P6 is the same as the anode of power supply E,
If the lamps LG and LR do not light up, but in the opposite case, the potentials of the output terminals P5 and P6 will be the same as the cathode end of the power source E, and the lamps LR and LG will be configured to light up, and the lamp LR will turn on.
, LG is preferably a light emitting diode.

A circuit consisting of constant current circuit 2, potentiometer PM3, and transistor Q3 is a circuit that starts a fourth voltage signal depending on the set shutter speed. Proc A3 is
a fourth voltage signal generated in the potentiometer PM3; the intensity of the subject light beam that has passed through the photographing lens and the aperture;
This aperture determining means receives a second voltage signal corresponding to the film sensitivity and compares both voltage signals to determine the aperture aperture.

This aperture determining means includes, for example, an electromagnet actuated by the output of the block A3, and while the aperture is being stopped down from the open position in connection with the release operation and before the start of exposure, the second voltage signal is applied to the fourth voltage signal. When the voltage signal becomes equal to the voltage signal, the electromagnet is operated to lock the aperture operation and determine the aperture. Block A4
is an exposure time control circuit that stores the second voltage signal by opening switch SW3 before the movable mirror is rotated from the observation position to the photographing position in connection with the release operation. It is held in a capacitor Cm, and in accordance with this held voltage, a count is started from the start of running of the leading curtain, and the exposure time is controlled by controlling the start of running of the trailing curtain.

Note that the exposure time control circuit A4 is controlled by the second voltage signal of the photometry section held by the storage capacitor Cm as described above, but is controlled by controlling the light rays from the subject on the film surface at the same time as the start of exposure. It is also possible to use means that photometers the reflected light, integrates it, and controls based on the integrated value; in this case, the storage capacitor Cm becomes unnecessary.

Next, to explain in detail the operation of the circuit shown in FIG. 2, it is assumed that the changeover switch SW2 is now closed to the contact a side (the case where it is closed to the contact b side will be described later).

Now, the shutter speed is set to 1 second.
To explain the case of 30 seconds, the sliding terminal PlO of the potentiometer PM3 outputs a voltage according to the number of seconds.

If a voltage exactly equal to this voltage is held on storage capacitor Cm, then block A4 controls the exposure time of one second. The aperture of the 30-photographing lens is initially at the open position, and at this time, a voltage signal for controlling the exposure time for the open aperture is generated at point P8.

At this time, the preset aperture value is set in advance to the minimum aperture aperture, for example Fl6, by the preset aperture setting means 11 shown in FIGS. 3 and 4. In response to this setting operation, the sliding terminal P9 of the potentiometer PM2 of the aperture ring 12 shown in FIG. 3 changes to the open aperture value, for example, Fl. 4
The voltage at the point P8 is moved away from the voltage at the point P8 by an amount of voltage corresponding to the seven stages of narrowing down between Fl6 and Fl6. Therefore, a voltage signal for controlling the exposure time with respect to the minimum aperture diameter Fl6 is generated at point P9 when the aperture of the photographic lens is in the open position.

Considering the lighting conditions of the lamps LG and LR when the aperture is in the open position, assuming that the film sensitivity is constant, first a voltage signal corresponding to a speed slower than -seconds is generated at point P8, that is. If a voltage lower than the voltage at point 30) 10 is output, a high level output is generated at point P5 and the lamp LG does not light up.

This corresponds to the state indicated by the broken line 4 in FIG. On the other hand, since the voltage at point P4 is higher than that at point P3, the output at point P6 becomes low level, and the other lamp LR lights up.

In this case, when the release operation is performed, the aperture is not stopped down but remains at the open aperture position, and the shutter speed is set such that exposure is performed at an appropriate exposure time corresponding to the open aperture.

This means that when only one lamp LR is lit, the aperture is open, the shutter speed is controlled at a slower speed than the preset shutter speed, and the exposure control in the mode (c) above is performed. . Next, as described above, the brightness of the subject increases and the voltage at point P8 becomes higher than the voltage at point PIO corresponding to the set shutter speed of 1 second, while the voltage at point P9 is not greater than the voltage at point PIO. In the case, i.e.
In FIG. 1, when the exposure value is between EV6 and EVl3, both lamps LR and LG are lit at the same time.

Here, the lamps LG and LR are assumed to emit green and red light, respectively, so if these lights are mixed and displayed as shown in Figure 5, both lights will be colored and appear yellow or yellow to the naked eye. It looks light-colored. Therefore, in FIG.
' lights up, or when the lamp window 4' lights up in Figure 4.
is displayed in this color, the shutter speed is
The shutter speed is controlled to the set speed of 1 second,
At 30 apertures, the exposure control of the mode (a) is performed, which is determined according to the brightness of the subject.

If the brightness of the subject increases further than the above state and the exposure value becomes EVl3 or more, that is, point PlO
Point ゝ ゛ 30P9 than the voltage according to one second of
If the voltage at the point P8 is higher than the voltage at the point P1O, and therefore the voltage at the point P8 becomes sufficiently higher than the voltage at the point P1O, only the lamp LG will light up in green.

The lighting of only the lamp LG indicates that the aperture is narrowed down to the minimum aperture Fl6 and that the shutter speed is higher than the set shutter speed of 1 second. The above description has been made of the case where the set shutter speed is set to 1 second, but the same display operation is performed when the shutter speed is set to any other desired shutter speed.

The display of various exposure control modes when the shutter speed is set with priority has been explained above, but in the above case, the preset aperture is set to the minimum aperture F: 16
Although the aperture setting ring 11 is not necessarily preset to the minimum aperture aperture, it may be set to an intermediate aperture value.

Next, the operation of the aperture determining means A3 is canceled to make it inactive, and in connection with the release operation, the aperture is always narrowed down to the preset aperture value set by the aperture setting ring 11, and the aperture is set to the preset aperture value. When performing the so-called aperture-priority automatic shutter speed control exposure mode in which the shutter speed is controlled according to the intensity of the subject light passing through the aperture narrowed down to
2 is manually switched from contact a to contact b.

In this case, the circuit shown in FIG. 2 operates as an aperture-priority exposure control circuit. That is, in conjunction with the release operation, the aperture aperture is narrowed down to the preset aperture value, regardless of the brightness of the subject. The voltage signal at point P8 at the time when the above narrowing down is completed is held in the memory capacitor Cm, and the shutter speed is automatically controlled based on this held voltage signal. Camera shake when shooting hand-held at shutter speed
, - 1 critical shutter speed that occurs, e.g. 1 second shutter speed
If the speed is set to 30, the voltage ratio circuits Al and A
2, in a region where the voltage level applied to the negative input terminals P2, P4 is higher than the voltage level slightly lower than the voltage level applied to the positive input terminals Pl, P3, the output terminals P5, P6 are connected lamp LG,
Adjust the settings so that both LR lights up.

By doing this, the lamps LG and LR will flash to indicate whether the shutter speed, which is automatically controlled based on the preset aperture aperture, is faster, slower, or equal to the camera shake limit shutter speed in milliseconds. It can be displayed by For example, as shown in Fig. 1, if the preset aperture value is set to F4 and one second is selected as the shutter speed to limit camera shake, both lamps LG and LR will turn off when the exposure value is near E9. When the EV value becomes larger than this, only the lamp LG lights up, and when the EV value becomes smaller than 9, only the lamp LR lights up. 3 to 5 show top views of cameras including the above circuit, and FIGS. 3 and 4 each show two camera embodiments using the circuit shown in FIG. 2. The difference between the two is limited to the arrangement of the lamp display windows. In both embodiments, a scale plate 2 having a shutter speed scale 3 is arranged on one side of the focusing plate 1 of the viewfinder 1, and an indicator 5 indicating the scale of the scale plate 2 has one end set to the shutter speed. It is fixedly wound around the rotating shaft of the dial 6, and the other end is fixed to a wire 8 fixed to the camera body via a tension spring 7, and is connected to the scale plate 2 according to the rotation setting of the shutter speed dial 6. slide along.

Resistance PM3 of potentiometer surrounding the above dial axis
is arranged, and a slider PlO is slidable on the shaft.
9 is the film sensitivity setting dial, and around the axis are:
A variable resistance of a potentiometer PMl is disposed, and a slider P7 is slidably disposed on the shaft.

10, as mentioned above, connects the switch SW2 to contact a or b.
This is a switching member that switches to .

An aperture preset ring 11 disposed on the objective lens of the camera can select a preset aperture value by matching an aperture value graduated around the ring with an index. A slider P9 is disposed on the aperture ring 12 which is biased to track the aperture preset ring 11, and the slider P9 slides on a variable resistance of a potentiometer PM2.

In FIG. 3, two lamp display windows 4 and 4' are opened above the scale plate 2, and lamps LG and LR are disposed in each of the display windows 4 and 4', and the blinking of the lamps LG and LR is provided in each display window. indicate.

In the embodiment shown in FIG. 4, only one lamp display window 47 is provided and displays the colors of both lit lamps in an additive manner.

For this purpose, as shown in FIG. 5, the lamp has two light emitting elements LG and LR that emit different colors disposed inside a globe W made of frosted glass, and when they blink, red, orange, and It is designed to be able to emit light in three colors, including green.
In this embodiment, the indicator 5 is formed with a yellow filter part 5a and a red filter part 5b.
By making the scale plate 2 transparent and covering its entire surface with a green filter, the entire scale plate can be seen as green, yellow, and red zones, and the colors of the lit lamps in the lamp display window can be differentiated. By matching the color within the zone of the scale plate, the shutter speed to be controlled during automatic exposure photography can be displayed.

As described above, according to the present invention, the shutter speed is set preferentially, the aperture is automatically determined according to the set shutter speed and the exposure value, and the actual shutter speed is The subject light passing through the determined aperture aperture is focused and metered, and control is performed based on the metered value, so that the aperture aperture cannot be automatically determined because there is no appropriate aperture for the set shutter speed. In the case of an exposure value, the aperture is either open or the minimum aperture aperture is selected depending on the exposure value, and the shutter speed is set according to the selected aperture aperture. In a TTL photometric single-lens reflex camera with functions that are modified and automatically controlled,
This is convenient for the photographer, as it is possible to accurately display which of the three types of exposure modes will be executed based on the differences in the operating modes of the light-emitting display means before narrowing down and starting the process. It is also possible to change the preset shutter speed by oneself according to the display.

Moreover, since it does not use an ammeter like conventional ones,
There is no risk of errors or damage due to camera vibrations or shocks, and it is possible to reliably display an extremely reliable display with good durability.

[Brief explanation of drawings]

FIG. 1 is a chart showing an example of the relationship between the aperture aperture, shutter speed, and exposure value E in order to explain the operation of the exposure display device according to the present invention, and FIG. 2 is a diagram showing a circuit of one embodiment of the present invention. figure,
Fig. 3 is a top view of the main parts mainly including the finder of the same embodiment, Fig. 4 is a top view of another embodiment of the same, and Fig. 5 is a side view of the lamp used in the second embodiment. It is a diagram. PD... Light receiving element, PMl, PM2, PM3・
...Potentiometer, P7, P9, PlO...
...Slider, AO...Amplifier circuit, P8...
...Second voltage signal generation point, Al, A2...
Voltage comparison circuit, LG, LR...Lamp, SW2
......Selector switch, SW3...Memory switch, Cm...Memory capacitor, A3...
... Aperture determining means, A4 ... Exposure time control circuit, 1 ... Focus plate of the viewfinder, 2 ...
...Scale plate, 4,4',47...Lamp display window, 5...Indicator, 6...Shutter speed dial, 9...Film sensitivity Setting dial, 1
0......Switching member of changeover switch SW2, 11.
...Aperture preset ring, 12...Aperture ring.

Claims (1)

[Claims] 1 It has a configuration that starts narrowing down the aperture toward a preset desired aperture value from aperture when the release operation is performed, and a first meter that measures the subject light that has passed through the photographing lens and the aperture, and measures the intensity of the subject light. a circuit that generates a voltage signal, and a circuit that generates a second voltage signal that corresponds to an appropriate shutter speed with respect to the aperture value at the time of photometry based on the first voltage signal and the voltage signal that corresponds to the set film sensitivity. , a third voltage signal corresponding to an appropriate shutter speed with respect to the preset aperture value is generated based on the second voltage signal before the start of stopping down and the voltage signal corresponding to the number of aperture steps from the preset aperture value to the open aperture value. A circuit for generating a fourth voltage signal corresponding to the set shutter speed, and a circuit for generating a fourth voltage signal corresponding to the set shutter speed, compare the second voltage signal and the fourth voltage signal at the same time as the start of narrowing down, and generate the second voltage signal. An aperture determining device that stops the aperture to determine the aperture when the level of the fourth voltage signal is reached, and a shutter that determines the aperture according to the shooting lens and the film sensitivity that sets the intensity of the subject light that has passed through the determined aperture. A TTL photometric single-lens reflex camera having a speed control device, a first comparison circuit that compares the magnitude of the level of the second voltage signal and the fourth voltage signal before the start of narrowing down; 3 voltage signal and the 4th voltage signal
a second comparison circuit that compares the level with the voltage signal of the first and second comparison circuits, and a light emitting display means that operates according to the outputs of the first and second comparison circuits; The circuit is configured such that when the level of the second voltage signal and the level of the third voltage signal before the start of narrowing down are on both sides of the level of the fourth voltage signal, both are on one side of the level of the fourth voltage signal. an exposure display, characterized in that the combination of outputs changes at one time and at the other side thereof, and is arranged so that the operating portion of the luminescent display means is made different based thereon; Device.