JPS5886524A - Exposure time storage device of ttl reflected-light measuring type camera - Google Patents

Abstract

PURPOSE:To store the exposure time of a TTL reflected light measuring type camera by selectively counting a clock of frequency corresponding to the exposure time obtained by APEX arithmetic prior to shutter releasing operation. CONSTITUTION:Before shutter releasing operation, exposure time is calculated by APEX basis through an operational amplifier 8 where the photoelectric converting element 9 for light metering and diode 10 for logarithmic conversion of a viewfinder system are connected, an A/D converting circuit 11, etc., to control a multiplexer 15 through a latch circuit 12. Then, a clock of high frequency varying with the quantity of photodetected light is selected. This clock is counted by a binary counter 58 through an inverter 59 which generates a high level output during TTL exposure through an optical converting element 32 for TTL reflected light metering after the shutter releasing operation and an AND gate 24 which is closed by an AND gate 56, etc. Then, the exposure time of a TTL reflected light metering type camera obtained by the counter 58 is stored in a latch circuit 54 to perform exposure time control, etc., repeatedly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure time storage device for a T'rL reflection metering camera, and more specifically, the present invention is an exposure time storage device for a T'rL reflection metering camera. T to close the shutter when the value reaches the appropriate value.
The present invention relates to an exposure time storage device for storing exposure time in a TL reflection photometry camera.

In a single-lens reflex camera with an aperture-priority storage metering system, the light is generally transmitted through the photographic lens. When the subject light is measured by the photoelectric conversion element for photometry in the viewfinder, the photometry output is calculated based on the exposure time, that is, the apex calculation is performed at the shutter time, and the information value is logarithmically compressed before the shutter release. Since this stored value is logarithmically expanded and retrieved when the shutter is released, the shutter seconds converted to real time are obtained at this time.

By the way, using this memory metering camera, for example,
If you are trying to photograph a subject whose brightness changes quickly over time or whose speed changes, the brightness of the subject will be different between the time the photometric value is stored and the time the shutter release is performed. The stored photometric value will be different from the actual one, and therefore, an appropriate layer time cannot be obtained.

On the other hand, in a single-lens reflex camera using the so-called TTL direct metering method, that is, a TTL reflection metering camera, when the shutter release is performed, the light passes through the photographic lens, and the front side of the shutter front curtain that started traveling by the shutter release and the same The light from the subject reflected on the film surface exposed by the movement of the front curtain is measured by a photoelectric conversion element for photometry, and this photometry output is immediately processed and used as a signal to control the rear curtain of the shutter.
An appropriate shutter speed can be obtained by accurately responding to the brightness of the subject while the shutter is open. Therefore, in recent years, the above-mentioned TTL reflection photometry type cameras have been increasingly used in place of memory photometry type cameras.

However, in the case of the above-mentioned memory metering camera, you can take as many pictures as you like with the shutter speed once memorized, so for example,
This is useful when you want to take a photo of a still subject such as a person or landscape by changing the composition within the shooting screen.
Conventionally, it has been considered extremely difficult to perform this with the above-mentioned TTL reflection photometry camera. In other words, when trying to memorize the shutter time with the above-mentioned TTL reflection metering camera, this type of camera does not have a function to store the shutter time calculated by Apex before the shutter release. It is possible to memorize the shutter time, but in this case, the shutter time is not the logarithmically compressed value calculated by Apex, but the logarithmically expanded /
Since real time of 2,000 to several tens of seconds is handled, a huge number of counters and registers are required, and the shutter time reproducing circuit attached thereto also becomes quite large in scale. Moreover, if, for example, high-speed seconds of /2000 seconds are counted using clock pulses of a frequency necessary to memorize them with a certain degree of accuracy, then slow seconds of several tens of seconds can also be counted using clock pulses of the same frequency. This would not only result in a huge number of counters, but also the memory accuracy would change exponentially as the shutter time changed, making it impractical. It has not been commercialized. 1 In view of the above points, it is an object of the present invention to select and switch the frequency of the clock pulse according to the exposure time calculated by Apex prior to shutter release, and to control the clock pulse frequency by the TTL reflection photometry output. Exposure time memory for photometric cameras, which counts the shutter open time and clock pulses of the above frequency, and stores the shutter seconds based on the frequency information of the clock pulses, the counting information, and k. We are in the process of providing equipment.

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is an electrical circuit diagram of an exposure time storage device of a TTL reflection metering camera showing an embodiment of the present invention. A non-inverting input terminal of an operational amplifier (hereinafter referred to as an operational amplifier) 1 is connected to a terminal 2 to which a reference voltage VR is applied, and a variable resistor 3 for setting film sensitivity connected in series. It is grounded via an aperture setting variable resistor 4 and a constant current regulator 5.

The connection point between the aperture setting variable resistor 4 and the constant current regulator 5 is PNP.
The emitter of the transistor 6 is connected to the output terminal of the operational amplifier 1. The inverting input terminal of operational amplifier 1 is transistor 6
, and the collector is grounded via a resistor 7. The output terminal of the operational amplifier 1 is connected to the non-inverting input terminal of the operational amplifier 8. operational amplifier 8
A photoelectric conversion element 9 for TTL open photometry disposed in the viewfinder of the camera is connected between the inverting input terminal and the non-inverting input terminal of the camera, with its anode facing toward the inverting input terminal. Further, a logarithmic compression diode 10 is connected between the inverting input terminal and the output terminal of the operational amplifier 8 with its anode facing toward the inverting input terminal. The output terminal of the operational amplifier 8 is connected to an A-D conversion circuit 11 for converting the apex-calculated shutter time output from the operational amplifier 8 into a digital value.

The AD conversion circuit 11 is connected to a latch circuit 12 constituting a first storage circuit, and the latch circuit 12 stores 4-pit AD conversion values. The output terminal of the latch circuit 12 is connected to a decoder 13 for converting the binary signal from the latch circuit 12 into a decimal signal. The decoder 13 is connected to a display 14 for displaying the shutter time using an LED, LCD, or the like.

The output terminal of each bit of the latch circuit 12 is connected to a multiplexer 15 for selecting the frequency of the clock pulse and switching its output state using a 4-bit binary signal from the latch circuit 12. The reference pulse is formed by three inverters 17, 18, 19 connected in series, a resistor 20 connected in parallel to these inverters, and a capacitor 21 in parallel to the inverters 17, 18. Each pulse is generated by a well-known reference pulse generation circuit 22. If the resistance value of the resistor 20 is R2o and the capacitance of the capacitor 21 is CH+, the period T of the reference pulse of frequency fHz generated from the reference pulse generation circuit 22 is Tex: C, .R2
It is o. When this reference pulse is led to the ripple counter 23, it is sequentially frequency-divided by the ripple counter 23, and from the ripple counter 23 to the multiplexer 1.
The lock pulse is guided to 5. The output terminal of the multiplexer 15 is connected to one input terminal of the AND gate 24, and the clock pulse of the frequency selected by the output of the latch circuit 12 is guided to the input terminal of the AND gate 24. It looks like this.

On the other hand, the output terminal of the operational amplifier 26 whose non-inverting input terminal is connected to the terminal 25 to which the reference voltage VR is applied is connected to the first non-inverting input terminal of the operational amplifier 29 via the analog switch 27. , analog switch 2
8 to the second non-inverting input terminal of the operational amplifier 29. A device is connected between the inverting input terminal of the operational amplifier 29 and the first non-inverting input terminal in the camera so as to receive the subject light transmitted through the photographing lens 30 and the real aperture 31 and reflected by the shutter front curtain surface and the film surface. A photoelectric conversion element 32 for TTL reflection photometry arranged in is connected with its anode facing the inverting input terminal side. The first non-inverting input terminal of the operational amplifier 29 is connected to the first integral force terminal.
One end of the integrating capacitor 34 is connected, and the other end of these integrating capacitors 33 and 34 is grounded.

Further, the one end of the second integrating capacitor 34 is connected to the collector of an NPN type transistor 35 with a logarithmic expansion angle,
The emitter of the transistor 35 is grounded. A terminal of this transistor 35 is connected to an output terminal of a DA conversion circuit 36.

The output terminal of the operational amplifier 29 is connected to each inverting input terminal of the operational amplifier 29, the operational amplifier 26, and an operational amplifier 37 forming a comparator.

The non-inverting input terminal of the operational amplifier 37 is connected to the reference voltage terminal 25 via a correction variable resistor 38 provided to enable correction of the shutter time after memorization, and is connected to the reference voltage terminal 25. It is grounded via a device 39. The output terminal of the operational amplifier 37 is a terminal 4 to which a power supply voltage vCC is applied via a magnet 40 for shutter rear curtain control.
I am able to connect back to 1.

On the other hand, each end of the trigger switch 43 is connected to a terminal 44 to which a power supply voltage Vcc is applied. and each other end is an AND gate 45
connected to each input terminal.

- The leaf terminal of this AND gate 45 is connected to the analog switch 280 control terminal. Further, the other end of the memory switch 42 is connected to one input terminal of an analog game 147 via an inverter 46. The other end of the trigger switch 43 is connected to the other input terminal of the AND gate 47 and is also grounded via a resistor 49. The output terminal of the AND gate 47 is connected to the control and leg terminals of the analog switch 27, and is connected to the first non-inverting input terminal and the second input terminal of the operational amplifier 29 depending on the output state of the AND gate 47. It is connected to the same operational amplifier 29 so that one of the non-inverting input terminals can be selected and switched.

The connection point between the trigger switch 43 and the resistor 49 is connected to one input terminal of an AND gate 56 via an inverter 55, and the output terminal of the inverter 55 is connected to a reset terminal of a binary counter 58 via an inverter 57. connected to the terminal. The above AND gate 56
The output terminal of the operational amplifier 37 is connected to one input terminal of the amplifier 37 via an inverter 59. The output terminal of the AND gate 56 is connected to the other input terminal of the AND gate 24. The output terminal of this AND gate 24 is connected to the input terminal of a binary counter 58,
said multiplexer 1 within the time that the shutter is open.
The number of clock pulses derived from 5 is counted by a binary counter 58. The output terminal of the binary counter 58 is connected to a latch circuit 54 constituting a second storage circuit so that a 4-bit binary signal is led thereto.

The output terminal of the NAND gate 50 is connected to this gate circuit 54, and the NAND gate is arranged so that a latch pulse is applied at the end of exposure by TTL reflection photometry. That is, the output terminal of the inverter 46 is connected to the first input terminal of the Nant gate 50, the output terminal of the operational amplifier 37 is directly connected to the second input terminal, and the output terminal of the operational amplifier 37 is directly connected to the third input terminal. The output terminal of the operational amplifier 37 connects to three inverters 51.5 connected in series.
They are connected via a delay circuit consisting of 2.53. Therefore, the latch circuit 54 stores the count from the binary counter 58 using a 4-bit binary signal when the shutter closes.

The output terminal of each pit of the iratch circuit 54 is connected to the DA conversion circuit 36. In addition, this DA conversion circuit 3
6 is connected to the output terminal of each bit of the latch circuit 12 which sends a frequency selection signal to the multiplexer 15. Therefore, when the clock pulse frequency information is guided to the DA converter circuit 36 by 4' pits and the clock pulse count information is guided by 4 bits, the D-A converter circuit 36 is guided to the above frequency. The binary signals of information and count information are converted into 8-bit analog voltages and sent to the base of the transistor 35.

The latch circuit 12 is connected to an output terminal of an ORD 60, and one input terminal of the ORD 60 is connected to an inverter 46 connected to the memory switch 42.
The output terminal of the inverter 62 is further connected to the output terminal of the inverter 62 . At the time of shutter release, the other input terminal of 60 changes from "low" level (hereinafter referred to as "L" level) to "...I" level (hereinafter referred to as "H" level), and the second input terminal of The latch circuit 12 is connected to a terminal 61 to which a signal Vs that becomes "L" level again at the end of the run is applied.However, if the shutter release is performed while the memory switch 42 is not closed, the latch circuit 12 At this time, the output of the A/D conversion circuit 11 is stored by a latch signal from the OR gate 60.

It was then configured as described above. The operation of the exposure time storage device of a TTL reflection metering camera will be explained.

When the camera's power switch (not shown) is turned on and the photographing lens is directed toward the subject, the photoelectric conversion element 9 for TTL open metering receives a photocurrent IpI corresponding to the brightness of the subject.
flows. Here, the resistance value of the variable resistor 3 for film sensitivity setting is R3, the resistance value of the variable resistor 4 for aperture setting is R4, the current flowing through the constant current regulator 5 is Ij + r, and the resistance value of resistor 7 is R.
,, the DC current amplification factor of transistor 6 is hFEl, and the pace-emitter junction reverse saturation current of transistor 6 is I.
If it is s, then it becomes. The output voltage v2 of the operational amplifier 8 is A
When guided to the -D conversion circuit 11, the signal is converted into a 4-bit binary signal by the same conversion circuit 11, and then guided to the latch circuit 12. The latch circuit 12 includes the memory switch 42
When the A is open without being operated, the signal led from the OR game) 60 is at the "L" level, so at this time the A
-The output of the D conversion circuit 11 is sent as is to the decoder 13, so the display 14 displays the shutter time in steps of IEv according to the amount of light received by the photoelectric conversion element 9. . Further, the output of the A-D converter circuit 11 through this latch circuit 12 is led to a multiplexer 15, and the multiplexer 15 generates a clock pulse of an appropriate frequency according to the apex value Tυ at the shutter time. At the same time, the D-A conversion circuit 36
I am also guided by

During normal photography without memory metering, the memory switch 42 is open, and the trigger switch 43 is closed when the shutter base is wound up. The output is "H" and the output of the AND gate 45 is 'L' level. Therefore, at this time, the operational amplifier 29 is activated by the 'H' level output of the AND gate 47.
The first non-inverting input terminal connected to the operational amplifier 29 is connected to the operational amplifier 29, the analog switch 27 is closed, and the first integrating capacitor 33 is charged to the reference voltage VRK by the output of the operational amplifier 26. ing. At this time, the analog switch 28 is set to AND gate 4.
Since the second integrating capacitor 34 is in an open state due to the L'' level output of No. 5, no voltage is applied to the second integrating capacitor 34 to charge it.

In this state, when the shutter release button is pressed,
The movable reflection mirror is flipped up to open the photographing optical path, and at the same time, the observation light is blocked from entering the finder. Immediately before the incidence of the observation light is cut off, the voltage Vs at the terminal 61; n
At this time, the output of the OR gate 60 changes to the L level or the H level, and the latch circuit 1
2 stores the output of the A/D conversion circuit 11 which A/D converts the output voltage v2 of the operational amplifier 8. Latch circuit 1
When the output of the A-D conversion circuit 11 is memorized and held by 2, the shutter time displayed on the display 14 becomes fixed.

Further, since the A-D conversion output stored in the launch circuit 12 is guided to the multiplexer 15, the multiplexer 15 is fixed to a state in which it generates a clock pulse of a predetermined frequency corresponding to the binary signal from the latch circuit 12. . That is, when the output of the latch circuit 12 is a binary signal corresponding to a maximum shutter speed of 000 seconds, for example, the multigrazer 1
5 is the highest frequency latch circuit 1 from the ripple counter 23
When the output of 2 is a binary signal corresponding to the minimum speed shutter time of several tens of seconds, the multiplexer 15 outputs a clock signal with a predetermined frequency selected according to the output state of the minimum switch circuit 12 from the ripple force/counter 23. The pulse is derived from multiplexer 15 as one input to AND gate 24 .

When the shooting optical path is opened and the shutter front curtain starts moving,
The photoelectric conversion element 32 for TTL reflection metering receives the light reflected from the subject light on the shutter front curtain surface and the film surface.At the time t when the shutter front curtain starts traveling (see Figure 2), the trigger switch 43 is opened, so at this time the output of the AND gate 47 changes to the "L" level as shown in FIG. 2, and the analog switch 27 is opened.
The charge in the first integrating capacitor 33 is increased at the time t by the photocurrent Ip2 of the photoelectric conversion element 32, which flows in proportion to the amount of light received by the photoelectric conversion element 32p. As the voltage is further discharged, the output voltage (3) of the operational amplifier 29 changes as shown in FIG. That is, the output voltage V3 of the operational amplifier 29 is set to the capacitance of the first integrating capacitor 33 as C1, and the output voltage V3 of the operational amplifier 29 at the above time is led to the inverting input terminal of the operational amplifier 3-7 and is applied to the non-inverting input terminal. Judgment voltage ■
Compared to 4. The determination voltage v4 is the resistance value of the correction variable resistor 38 as R38, and the current flowing through the constant current regulator 39 as I.
If J2, then V, = VR-R88·Ijt.

By comparing the output voltage v3 of the operational amplifier 29 and the determination voltage v4, the output of the i operational amplifier 31 is at the L'' level while ■3>■.The output of the operational amplifier 37 is at the L'' level.
While at the level, the magnet 40 is energized and restrains the shutter trailing curtain in a charged winding state. And while this shutter is open,
The output of the AND gate 56 is ITHt as shown in FIG.
+ level. Therefore, from ANDGATE 24,
As shown in FIG. 2, a clock pulse of a predetermined frequency selected quickly in the IEV step by the TTL open photometry output is output only while the shutter is open by the TTL reflection photometry output. The binary counter 58 indicates the time t when the trigger switch 43 is opened. Since the reset signal is given through the inverters 55 and 57,
The counter 58 is counted at the above-mentioned time point t. After the count contents are once reset, the number of clock pulses derived from the AND gate 24 is counted. That is, the binary counter 58 counts the actual shutter time during the TTL reflection photometry using pulses of a predetermined frequency. binary counter 5
The count value of 8 is sent to the latch circuit 54 as a 4-pit binary 1)'' signal.

The output voltage v3 of the operational amplifier 29 gradually decreases,
■, When ≦'V4, the operational amplifier 37 at this point t1
The output changes to H'' level and the magnet 40 is de-energized, so at this time the shutter trailing curtain is released from its restraint and runs, covering the film surface and completing the exposure.At time t□, the operational amplifier 37 When the output reaches the 'H' level, the output power of the inverter 53 increases slightly after the same point in time.
At this time, the second
As shown in the figure, a short-time L'' level latch pulse is applied from the Nant gate 50 to the latch circuit 54, and the latch circuit 54 receives the count value of the binary counter 58, that is, the clock pulse pulse of the predetermined frequency. The counted value is stored at the rising edge of the latch pulse.

Therefore, the binary signal sent from the latch circuit 54 to the DA converter circuit 36 is fixed at this stored value.

In this way, when a photograph is taken without the memory switch 42 being closed, 1 (so-called TTL direct) 11ft11 light is generated based on the amount of light received by the TTL reflection light electric conversion element 32. The shutter time at this time is stored as a clock pulse count.

The frequency of this clock pulse is selected in the IEV step based on the amount of light received by the photoelectric conversion element 9 for TTL opening, and as mentioned above, the faster the shutter speed, the higher the frequency is selected. There is. Therefore, the shutter time is stored in a matrix in the latch circuit 54 using clock pulse frequency information and its pulse count information. The faster the shutter time is, the higher the frequency is counted, so that the resolution of storage accuracy is made uniform, and the binary counter 58, latch circuit 54, etc. can be made smaller.

Next, if you want to take a picture with the same shutter speed as in the exposure control using TTL reflection metering, that is, if you want to perform exposure control using memory metering, close the memory switch 42 before releasing the shutter. to be accomplished. Above T
At the end of exposure control using T L reflection photometry, the signal from the OR gate 60 to the latch circuit 12 once goes to the "L" level, but when the memory switch 42 is closed, the output of the OR gate 60 becomes 'H' again at this point. “Turn to the level.

When performing exposure control photography using memory metering - 1 After the previous exposure control exposure control photography using TTL reflection metering is completed, immediately close the memory switch 42 until the shooting composition is reached. , the latch circuit 12
Since the output is fixed to the same state as the previous output state, the display 14 displays the shutter time that is equal to the previous shutter time.

Further, when the shutter curtain is rolled up, the trigger switch 43 is closed together with the memory switch 42, so at this time, the output of the AND gate 47 is n L
IT level, the output of the AND gate 45 is "HIT level. Therefore, at this time, the IIL of the AND gate 47
The second non-inverting input terminal of the operational amplifier 29 is connected to the I+ level output, and the analog switch 28 is closed due to the H'' level output of the AND gate 45. Integrating capacitor 34 is charged to reference voltage VR by the output of operational amplifier 26.

In this state, when the shutter release button is pressed,
Since the shutter front curtain starts running and the trigger switch 43 is opened, at this time the output of the AND gate 45 becomes L".
When the level changes, the analog switch 28 opens.

Since the memory output from the latch circuit 12 and the memory output from the latch circuit 54 are led to the D-A converter circuit 36, the latch circuit 54 is guided to the D-A converter circuit 36.
The output of the latch circuit 12 is DA-converted based on the output of the latch circuit 12, and this DA-converted analog signal flows into the base of the logarithmic expansion transistor 35, so that when the analog switch 28 is opened, Then, the charge stored in the second integrating capacitor 34 starts discharging through the transistor 35. The binary signal led from the latch circuit 12 to the D-A conversion circuit 36 is based on the TTL open photometry output and corresponds to a predetermined frequency selected by the multiplexer 15. The binary signal to be generated is the T of the previous photograph of the clock pulse emitted at the above-mentioned predetermined frequency.
Since it corresponds to the number of pulses counted based on the TL reflection photometry output, in the D-A conversion circuit 36, the number of pulses of the predetermined frequency stored in the latch circuit 54 is T'TL.
The reflected power is converted into an analog signal, and the transistor 35 is controlled by the analog signal.

When the transistor 35 is controlled according to the output of the D-A conversion circuit 36 and collector current IQ flows, the electric charge of the second integrating capacitor 34 is discharged according to the collector current IQ, If the capacitance of the integrating capacitor 34 is C2, then Then, the output voltage v3 of the operational amplifier 29 gradually decreases, and when it is compared with the judgment voltage η of the operational amplifier 37 and the relationship of v3≦v4 is established, the output of the operational amplifier 37 becomes H'' level and the magnet 40 is energized. is cut off, the shutter trailing curtain runs, and the exposure control based on the above-mentioned stored value is completed.

Even if the exposure control based on the memorized value is completed, if the memorization switch 42 is kept closed, the latch circuit 12.54 will maintain the memorized state. Similarly, by releasing the shutter, a photograph can be taken at the shutter time of the first TTL reflection metering, and this can be repeated many times. Therefore, for the first shooting, close the memory switch 42 and take a picture with exposure control using TTL reflection J11 light, and then for the second and subsequent shots, close the memory switch 42 and take a picture. By changing the composition, you can take multiple photos with different compositions using the same shutter speed depending on the subject you want to photograph.

In addition, when shooting with exposure control based on the above-mentioned stored value, if the resistance value of the variable correction resistor 38 is appropriately varied, the judgment voltage (4) changes, so that an appropriate correction can be applied to the shutter speed. , various types of memory photography can be performed.

As described above, according to the present invention, by performing photography using TTL reflection measurement, the shutter time and time at which exposure was controlled at this time are automatically stored, so that the stored value It is possible to control the exposure of the shutter speed based on In addition, the actual shutter time based on the TTL reflection photometry output is counted using a clock pulse of a different predetermined frequency corresponding to the shutter time, and this count is stored, so a small-scale device such as a counter can be used. It can be used and constructed at low cost, and it also exhibits excellent effects such as making the resolution of storage accuracy uniform for all shutter seconds.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing an embodiment of the exposure time storage device of the present invention, and FIG. 2 is a time chart illustrating the operation of the storage device shown in FIG. 1. 9...Photoelectric conversion element 11 for TTL open photometry
...A-D conversion circuit 12...Latch circuit (first storage circuit) 15...
...Multiplexer (clock pulse generation circuit) 32
...”T T L photoelectric conversion element 36 for reflection photometry
...D-A conversion circuit 54...Latch circuit (second storage circuit) 58...
...Binary counter (counting circuit) procedural amendment (voluntary) January 2B, 1980 Haruki Shimazono, Commissioner of the Patent Office1, Indication of the case Patent Application No. 184723 of 19842, Title of the invention TTL reflective sub-light Exposure time record lowering device 3 of a type camera and its relation to the case of the person making the correction Patent applicant location: 2-43-2 Hatagaya, Tani-ku, Shibu, Tokyo
Name (037) Olympus Optical Industry Co., Ltd. 4
8. Agent (No. 324-2700) 5. Subject of amendment Column 6 of “Detailed Description of the Invention” of the specification, Contents of amendment (1) “Non-inverted input” in line 12 of page 10 of the specification
For the terminal, delete the part after ``'' and before ``variable resistor 38'' in the 14th line, and substitute ``for shutter control film sensitivity setting''. (2) ``For amendment'' written at the end of line 9 on page 19 of the same document shall be deleted. (3) "Correction variable resistor 38" written in line 7 of page 26 has been changed to "variable resistor 38 for film sensitivity setting for shifter control."

Claims (1)

[Claims] The subject light transmitted through the photographic lens and then reflected by the front surface of the shutter front curtain and the film surface of the exposure device is photometered, and based on this TTL reflection photometry output. In a TTL reflection metering camera that determines the exposure time by controlling the start of travel of the shutter trailing curtain, the exposure time is calculated as a digital value by apex using the aperture metering value, film sensitivity value, aperture value, etc. prior to shutter release. A first memory circuit that stores the output of the A-D converter circuit; and a first memory circuit that stores the output of the A-D converter circuit; a clock pulse generation circuit that generates clock pulses of different predetermined frequencies) - a counting circuit that counts the output pulses from the clock pulse generation circuit by the time that the shutter is open, which is controlled by the TTL reflection photometry output; a second storage circuit that stores the output of the counting circuit; a D-A conversion circuit that converts the output of the second storage circuit into an analog value and obtains a memory photometry signal corresponding to the TTL reflection photometry output from frequency information and count information; Exposure time storage device for type cameras.