JPS59132288A - Electronic camera - Google Patents

Abstract

PURPOSE:To attain high speed pickup by increasing the scanning frequency for sweep-out scanning before pickup more than the scanning frequency for readout scanning after pickup to prevent the reduction in the picture quality due to dark current. CONSTITUTION:An image sensor driving circuit 20 driving an image sensor 12 is provided with a one-screen scanning circuit 88, the 1st oscillating circuit 82 and the 2nd oscillating circuit 83. Then, the scanning circuit 88 gives a sweep-out scanning signal to the image sensor 12 via the oscillating circuit 83 when a release start signal is inputted, and when an exposure end signal is inputted, a readout scanning signal is given to the image sensor 12 via the oscillating circuit 82. The relation between the frequency f2 of the oscillating circuit 83 and the frequency f1 of the oscillating circuit 82 is set as f2>f1. Thus, the reduction in the picture quality due to dark current is prevented and the high speed pickup is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single-lens reflex electronic camera that includes an imaging device that photoelectrically converts a subject image and a storage device that stores still image signals obtained by the imaging device.

2. Description of the Related Art A device that uses an imaging device such as a solid-state imaging device to obtain an electrical signal according to the brightness of a subject image and stores the electrical signal in a magnetic disk or semiconductor memory is known as an electronic camera. This electronic camera has advantages over conventional film-based cameras, such as no need for film that requires chemical processing, and rapid playback using a television receiver. Many proposals have been made so far as replacement cameras.

In this electronic camera, the imaging device is electrically scanned before and after taking a picture, and before taking a picture, unnecessary charge that has been accumulated is discharged, and after the picture is taken, the charge that has been accumulated at the time of taking a picture is read out. Since no consideration is given to the extrusion signal and the readout signal, and both are performed at the same speed, there is a problem that the image deteriorates or the photographing operation is delayed. For example, in conventional video cameras, the subject image is photoelectrically converted using an imaging device, similar to electronic cameras, but the vertical synchronization signal that drives the imaging device is periodically transmitted every one field period (1/60 seconds). It is a pulse. In this method, the pulse is used to discharge unnecessary accumulated charges before shooting still images and to read out the charges that become the still image signal.
Also, it takes time from the end of exposure to the readout of charges, and image quality deteriorates due to an unnecessary increase in dark current. Furthermore, it takes a long time from when the release switch is turned on until exposure to the imaging device becomes possible, making it difficult to photograph fast-moving subjects.

In addition, the finder device used in this electronic camera can use any finder system used in conventional film cameras, and by using the image pickup device, it can A formula viewfinder is also available. Among these finder systems, the so-called -eye reflex finder has the most excellent functions in that the viewfinder field of view and the imaging range are equal, and interchangeable lenses can be used.

- In an eye reflex finder, a semi-transparent mirror is placed in the imaging light flux to branch the light to the finder optical system, and a so-called quick return mirror is used to switch the imaging light flux between the finder optical system and the shooting optical system. There is something to guide you.

Although the one-sided quick return mirror has a movable part, it has many advantages over one that uses a semi-transparent mirror, such as a brighter finder image and no attenuation of the amount of light to the imaging device. Conceivable.

In order to equip an electronic camera with a quick return mirror for an eye reflex finder, the drive device for the quick return mirror and the imaging device must be electrically connected, which is different from cameras that use conventional film. A new mechanism is required.

However, because conventional electronic cameras use a single-lens reflex viewfinder that uses a semi-transparent mirror, the viewfinder image becomes dark and the amount of light to the imaging device is inevitably attenuated. No image was obtained. In particular, the sensitivity of current solid-state image sensors is lower than that of film, so attenuation of the amount of light is a major drawback.

In order to charge the mirror and shutter electrically, it is possible to use the motor drive device of a conventional film-using camera, but the known motor drive mechanism uses a large winding blade to wind the film. The winding mechanism has a relatively long winding time, so the mechanism is inevitably complicated, and the electric circuit is also complicated because it requires a switch mechanism to indicate the completion of winding. It cannot be used for electronic cameras.

The present invention is characterized in that the first problem, that is, the deterioration of image quality due to dark current and the delay in photographing operation, is solved by making the scanning frequency of the exposure scan for the imaging device higher than the scanning frequency of the readout scan. It is said that In other words, since the readout scan is performed after the shooting is completed, there is no need to perform it as quickly as possible, but if the readout scan is made faster than the readout scan, then after the shirt release,
The time required to perform exposure is shortened, so there is no deterioration in image quality due to dark current, and exposure can be performed quickly after release scanning.

In addition, to solve the problem that the finder image is dark and the amount of light to the imaging device is attenuated, by using a quick return mirror, it is possible to make a bright finder image and maximize the amount of light to the imaging device to capture a dark subject. This makes it possible to obtain still images with good image quality.

Furthermore, the charging mechanism for the shutter and mirror has a simple configuration without a winding mechanism, and the drive motor is driven at the same time as the shutter finishes running, and stops at the same time as charging is completed, allowing for continuous shooting. I'm getting a camera.

The invention will now be described with reference to the illustrated embodiments. 1 and 2 show the basic configuration of the electronic camera of the present invention, which consists of a lens barrel having a photographic lens 11 and a body B, in which a subject is imaged by the photographic lens 11. It contains ten image processing elements. That is, an imaging device (image sensor) 12 is disposed on the optical axis (on the imaging light flux), and a shutter 25 and a quick return mirror 13 are disposed in front of the image sensor 12. The quick return mirror 13 normally forms an angle of 45 degrees with respect to the optical axis, and reflects the imaging light flux to the finder optical system 14, which includes a focus plate 15, a mirror 16, a relay lens 17, and an eyepiece lens 19, but when shooting, the imaging light flux It is evacuated from inside and gives a luminous flux to the image sensor 12 side. The finder optical system 14 may use a conventional pentaprism. Therefore, according to the optical system of this electronic camera, the image of the subject is always guided to the finder optical system 14, re-imaged on the re-imaging surface 18, and can be observed with the eyepiece lens 19, and when shooting, a quick return The imaging light flux can be guided to the image sensor 12 side by flipping up the mirror 13.

The electric charge accumulated in the image sensor 12 is discharged and read out by an image sensor drive circuit 20, an exposure control circuit 21, a photometric element 22, a mirror drive system 23, a shutter drive system 24, a shutter 25, a signal processing circuit 26, and a storage device 27. According to Ohji, the process is carried out as follows (the gist of the present invention is a specific example of the image sensor drive circuit 20, but before explaining the details, the overall operation of the present electronic camera will first be explained. ). The image sensor driving circuit 20 performs scanning for one field or one frame period by pressing down the release switch during photographing, and discharges unnecessary charges accumulated in the image sensor 12. On the other hand, the exposure control circuit 21 outputs an exposure control signal in accordance with the output of the photometric element 2'2 which photoelectrically converts the brightness of the subject image. The photometric element 22 is the finder optical system 14
Suitable for installation inside. The mirror drive system 23 is described in the quick return mirror 13 after the extrusion scanning is completed.
The shutter drive system 24, which receives the output from the exposure control circuit 21, opens the shutter 25. After proper exposure, the shutter 25 closes. When exposure is complete, quick return mirror 1
3 returns to the state before evacuation, and at the same time, the image sensor drive circuit 20 scans one field or one frame, and the charge accumulated in the image sensor 12 when the shank 25 is in the open state is transferred to the signal processing circuit. 26. The image signal obtained by the signal processing circuit 26 is subjected to appropriate processing and stored in the storage device 27. On the other hand, when the shutter 25 is opened, motors (described later) included in the shutter drive system 24 and the mirror drive system 23 are driven to restore the driving force of the shutter 25 and the quick return mirror 13 in preparation for the next photograph.

FIG. 3 shows specific examples of drive mechanisms for the quick return mirror 13 and shutter 25, and various timing switches. The shutter 25 is a focal plane shutter consisting of a front curtain 32 and a rear curtain 34.
are pulled to the right in the figure by a leading curtain spring 40 and a trailing curtain spring 42, respectively. The leading curtain locking pawl 39, the trailing curtain locking pawl 41, . The leading curtain locking pawl 39 releases the leading curtain from the leading curtain 8-29c, and the trailing curtain locking pawl 41 releases the engagement with the leading curtain 32 and the trailing curtain 34, respectively, by the trailing curtain magnet 31. Charging the shutter 25,
That is, the motor 35 charges the leading curtain 32 and the trailing curtain 34. That is, when the motor 35 rotates once, the shutter charge lever 50 reciprocates once by the crank lever 49, the shutter charge lever 50 pushes the front curtain 32a, charges the front curtain 32 against the force of the front curtain spring 40, and at the same time The rear curtain 34a is pushed by the front curtain 32, and the rear curtain 34 is also pushed by the front curtain 3.
2 and is charged against the force of the rear curtain spring 42. The shutter switch 33 is turned on when the front curtain 32 is charged, and turned off when the front curtain 32 starts running.

The quick return mirror 13 rotates (swings) around a mirror rotation shaft 29b that is integrally provided at its rear end, and the leading curtain lock release lever 29c is fixed to this mirror rotation shaft 29b. There is.

29d is a torsion spring that biases the quick return mirror 13 in a downward direction. A mirror up lever 37 and a mirror down lever 44 are slidably supported on the sides of the mirror box.The mirror up lever 37 is moved forward in the figure by a spring 38, and the mirror down lever 44 is moved backward in the figure by a spring 45. are drawn to each. The mirror up locking pawl 36 restricts the movement of the mirror up lever 37, and is engaged with and disengaged from the mirror up lever 37 by the mirror magnet 28. A mirror up lever 37a that engages with a pin 29a protruding from the side surface of the quick return mirror 13 is provided behind the mirror up lever 37, and when the mirror up lever 37 is slid forward by a spring 38, the quick return mirror 13 jumps up. The bin 34a projected from the trailing curtain 34 hits the mirror down lever locking claw 43 at the end of travel to free the mirror up lever 44, and the mirror up lever 44 lowers the quick return mirror 13. This quick return mirror 13 is attached with a mirror switch 30 that is turned on when the mirror 13 begins to rise and turned off when it descends again. Further, the mirror down lever 44 and the mirror up lever 37 are operated by the motor 3.
The mirror charge lever 48 is charged by a mirror charge lever 48 that swings at a constant angle by a gear 47 meshing with a gear 46 of No. 5.

The operation of the apparatus having the structure shown in Jx and the processing of signals generated with the operation are performed as shown in the timing chart shown in FIG. When the release button on the camera body is pressed, the release switch is turned on, and at the same time as the release switch is turned on, a vertical synchronization signal is generated from the image sensor drive circuit 20 to the image sensor, and a scan corresponding to one screen (L field or one frame) is generated. is carried out, and the unnecessary charge that had been accumulated up to that point is discharged. When this extrusion scan is completed, a release signal (ON) is sent to the mirror magnet 28.
is served. Then, the mirror up locking pawl 36 and the mirror up lever 37 are disengaged - the cB lever 37 is pulled by the spring 38 and slides forward, pushing the bin 29a, that is, the quick return mirror 13 upward on the inclined surface 37a. .

At the beginning of this upward movement of the mirror 13, the mirror switch 3
0 is turned on, and at the same time, the trailing curtain magnet 31 is also turned on, locking the trailing curtain 34 (at this time, the trailing curtain 34 is integrated with the leading curtain 32 at the charging position).

When the quick return mirror 13 flips up, at its final stage, the leading curtain locking release lever 29c hits the leading curtain locking pawl 39 and releases the locking with the leading curtain 32. Then, the front curtain 32 moves while being pulled by the front curtain spring 40, and the image sensor 12 is exposed to light. Further, the shutter switch 33 is turned off at the beginning of the movement of the front curtain 32, and from that time on, the exposure control circuit 2
After the exposure time calculated in step 1 has elapsed, the trailing curtain locking claw 4
1, a release signal (off) is sent to the locking claw 41 and the rear curtain 34
removed from Therefore, the trailing curtain 34 runs while being pulled by the trailing curtain spring 42, and the exposure is completed. When the rear curtain 34 finishes traveling, the pin 34a releases the mirror down lever locking claw 43, and the mirror down lever 44 is then pulled by the hene 45 and slides, and at this time the mirror up lever 37 also slides together. So quick return mirror 13
is lowered by its own weight and the force of the torsion spring 29d.

When the mirror 13 returns, the mirror switch 30 is turned off, and this return signal causes the image sensor drive circuit 2 to
A vertical synchronizing signal is generated at 0, this signal is applied to the image sensor 12, scanning corresponding to one screen (l field or l frame) is performed, and the charge accumulated when the shutter 25 is in the open state is sent to the signal processing circuit. 26 and stored in the storage device 27.

On the other hand, when the mirror switch 30 is turned off, the motor 35 starts to be driven at the same time, and the quick return mirror 13 and shutter 25 are charged.

That is, the rotation of the motor 35 is transmitted to the gears 46 and 47, and the mirror charge lever 48 swings, so the mirror down lever 44 slides forward, the spring 38 and the spring 45 are charged, and the mirror down lever 44 moves the mirror down. The lever is stopped by the locking pawl 43, and mirror charging is completed. Shutter charging is performed by reciprocating the shutter charging lever 50 via the crank lever 49 by rotation of the gear 46. That is, first act 3
When the shutter charge lever 50 pushes the second pin 32a, the bin 34a is pushed by the front curtain 32, and the front curtain 32 and the rear curtain 34 slide together. At this time, the leading curtain spring 40 and the trailing curtain spring 42 are charged, the leading curtain 32 is hooked to the leading curtain locking pawl 39, and the trailing curtain 34 is hooked to the trailing curtain locking pawl 41 and stopped, completing shutter charging. do. At this final stage, the shutter switch 33 is turned on again by the front curtain 32, and this signal outputs a drive stop signal for the motor 35. After receiving the stop signal, the motor 35 moves for a while due to inertia and stops at the original position before charging.

However, the greatest feature of the present invention lies in the image sensor drive circuit 20. Figure 5 shows the block diagram.
The image sensor drive circuit 20 includes a first oscillation circuit 82, a second oscillation circuit 83, a horizontal drive pulse generation circuit 84, a horizontal synchronization signal generation circuit 85, a vertical drive pulse generation circuit 86, a vertical synchronization signal generation circuit 87, and one-screen scanning. It is composed of a circuit 88. The one-screen scanning circuit 88 gives an exposure scanning signal to the image sensor 12 via the second oscillation circuit 83 when the release start signal (signal of the release switch 51) is input, and provides an exposure completion signal (signal of the mirror switch 30). When input, a readout scanning signal is given to the image sensor 12 via the first oscillation circuit 82, and the frequency f2 generated by the second oscillation circuit 83 is different from the frequency f1 of the signal generated by the first oscillation circuit 82. at least f between
The relationship 2>f+ (for example, f2=nf1.n is a positive integer) is satisfied. That is, the release switch 51
When this signal is input to the one-screen scanning circuit 88 to enter the release state, the scanning circuit 88 resets the first oscillation circuit 82, and at this time, the second oscillation circuit 83 is released from the reset state. When the second oscillation circuit 83 is released from reset, it returns to the initial state, and the horizontal drive pulse generation circuit 84, the horizontal synchronization signal generation circuit 85, the vertical drive pulse generation circuit 86, the vertical drive pulse generation circuit 86, and the vertical synchronization signal generation circuit 87
send a pulse to. Each circuit receiving this pulse receives horizontal drive pulses ΦH1, ΦH2 and horizontal synchronizing signal ΦH.
in, vertical drive pulses Φ■l, ΦV2, and vertical synchronization signal ΦVin are produced. When these signals are sent to the image sensor 12, the image sensor operates and outputs a video signal. The vertical synchronizing signal ΦVin is also input to the one-screen scanning circuit 88, and when the scanning of one field or one frame is completed, the oscillation circuit 83 enters a reset state. At this time, the first oscillation circuit 82 remains in the reset state. Next, when the signal from the mirror switch 30 is input to the one-screen scanning circuit 88 and the readout scanning starts, the first oscillation circuit 82 is reset again and one screen (L field or one frame) is scanned in the same way. It is done. The video signal output from the image sensor 12 at this time becomes a still image signal.

FIG. 6 is a detailed circuit diagram of the one-screen scanning circuit 88. When the release button is pressed, the release state becomes "°L" level. When the "A" word of the button 51 is input to the one-screen scanning circuit 88, it is inverted by the inverter 98 and becomes the "H'" level, and the capacitor 99 , resistance 1
The trigger pulse obtained by the differentiating circuit consisting of
These can be reset manually. Therefore, the RS flip-flop 97 and the D flip-flop 9, which were set to "H" level by the capacitor 95 and the resistor 96,
The C terminal of No. 4 becomes the “L” level. The output from the C terminal, that is, the reset signal ΦR2, changes from H” level to “
Since the level becomes L11, the reset of the second oscillation circuit 83 is released.

From that point on, the second oscillation circuit 83 starts working, and a driving pulse for the image sensor 12 is generated, and the vertical synchronizing signal ΦVin is generated.
is input to the C terminal of the counter 91. When this vertical synchronizing signal Φ■in is counted 3 times, the output of the AND gate 92 goes to the °°H level, and passes through the OR gate 93 to D-flip, mbf-flo, and so on.

The power is input manually to the C terminal of step 94. At this time, the C terminal of the D flip-flop goes to the "H" level, so the reset signal ΦR2, which is the output of the C terminal, goes to the H" level, and the second oscillation circuit 83 is reset for one output. At the same time, the output of the AND gate 92 is input to the NOR gate 105.In the flip-flop composed of NOR gates 104 and 105, NOR gate 1 is input when the power is turned on.
Since the output of 04 is at the "H" level, even if a signal at the "H" level is input to the NOR gate 105, the output of the NOR gate remains at the "H" level.

Next, after the exposure is completed, the signal of the mirror switch 30 is set to “L”.
When it reaches the "o" level, this "L" level signal is inverted by the inverter 101 and becomes the "H" level, and then becomes a positive trigger pulse by a differentiating circuit consisting of a capacitor 102 and a resistor 103. This positive trigger pulse is At the same time as resetting the counter 91 through the OR gate 108, the flip-flop constituted by the NOR gates 104 and 105 is inverted, and the output of the NOR gate lO4, which was currently at the "H" level, is brought to the "L" level. Therefore, it is the output of the NOR gate. Reset signal ΦR
1 changes from the "H" level to the "L" level, the reset of the first oscillation circuit 82 is released. As a result of this release, the first oscillation circuit operates, and a pulse for driving the image sensor is created, and the vertical synchronization signal ΦVin is applied to the C of the counter 91.
input to the terminal. Here, the counter 91 counts the vertical synchronizing signal ΦVl. When the count reaches 3, the output of the AND gate becomes “H” level, and the NOR gate 104
．． The flip-flop composed of 105 is inverted again, and the output of the Noah game I, which has been at the "L11 level", becomes "H+ level", so the first oscillation circuit 82 and the second oscillation circuit 83 are all reset. , the image sensor stops driving. In this way, the exposure scan and readout scan corresponding to one frame are performed, and as mentioned above, the frequency of the second oscillation circuit 83 that operates during the exposure scan is the same as that of the first oscillation circuit that operates during the readout scan. Since the frequency is set higher than that of 82, exposure scanning is performed immediately after the release signal is received in a short period of time. When scanning one field, the vertical synchronizing signal ΦV1 may be configured to be counted by two by the counter 91.

FIG. 7a shows the image sensor drive circuit 2 which generates the vertical synchronizing signal ΦVl as described above based on the signals of the release switch 51 and the mirror switch 30, and performs unnecessary charge discharge scanning and image signal readout scanning.
0 shows a timing chart of 0. It is understood that the exposure scan is performed in a shorter time than the readout scan. Further, FIG. 7b shows horizontal drive nodes ΦH1, Φ for driving the image sensor drive circuit 20.
H2, horizontal synchronization signal ΦHim, vertical drive node Φ■l
, Φv2 and the vertical synchronization signal ΦVin.

FIG. 8 shows a specific example of an electric circuit for operating the electronic camera. In the figure, a mirror switch 30, a shutter switch 33, a photometric element 22, a mirror magnet 2
8. Rear curtain magnet 31 and motor 35 are the same elements as those in the above explanation, and in addition to these, the switch 51 includes a release switch 51 that turns on when the release button is pressed, and records an image signal. A memory switch 54 that is used when the self-timer is used, and a self-switch 66 that is turned on when the self-timer is used are provided. Now, in the same figure, before shooting, the mirror switch 30 and the release switch 51
, the memory switch 54 and the self-switch 66 are off, and the shutter switch 33 is on. Since the release switch 51 is off, the transistor 55 is not conductive, and no power is supplied to the circuit, so the circuit does not operate.

When the release switch 51 is turned on (the shutter button is pressed), the transistor 55 becomes conductive and power is supplied to the circuit. Power supply timer 56 generates an output that causes transistor 57 to conduct for a certain period of time after power is supplied to the circuit. Therefore, even if the release switch 51 is turned off, power supply to the circuit is maintained for a certain period of time.

The photometric circuit operates when power is supplied to the circuit. The photocurrent flowing through the photometric element 22 is logarithmically compressed by the transistor 59, and a voltage corresponding to By is generated at the base. On the other hand, variable resistor 60 is set according to film sensitivity and aperture.
A constant current flows through and a voltage corresponding to 5V-Ay is generated across it. Therefore, a voltage corresponding to By+5v-Av, that is, Tv, is generated at the emitter and terminal of the transistor 61. By the way, when power is supplied to the circuit, since the mirror switch 30 is off, the control signal of the memory switch 54 becomes "L" and the memory switch 54 is turned on.The voltage corresponding to Tv is applied to the level shift resistor and memory. The signal is transmitted to the memory capacitor 63 via the switch 54.

Now, when power is supplied to the circuit, the delay circuit 64 sends an "H" signal to the S terminal of the RS flip-flop 65 after a certain period of time after receiving the vertical synchronizing signal. Furthermore, when using the self-timer, the self-switch 66 is turned on.

At this time, the delay circuit 64 sends an "H" signal to the S terminal of the RS flip-flop 65 after the time set by the self-timer has elapsed since receiving the vertical synchronizing signal. On the other hand, since the mirror switch 30 is off, the inverter 67
The R terminal via the terminal is “L”. Therefore, the S terminal “
When the H" signal is received, the RS flip-flop 65 turns on the transistor 68 and energizes the mirror magnet 28.

When the mirror magnet 28 is energized, the aforementioned mechanical mechanism is turned on, and the mirror switch 3o is turned on, making the transistor 7o conductive. On the other hand, since the shutter switch 33 is on, the transistor 71 is conductive, and therefore the output of the comparator 72 is "L". Therefore, the transistor 73 is not conductive, but the transistor 74 is conductive, and the trailing curtain magnet 31 is energized. Further, since the mirror switch 3o is turned on, the control signal of the memory switch 54 becomes "L", and the memory switch 54 is turned off.

Next, when the front curtain 32 is moved and the shutter switch 33 is turned off by the aforementioned mechanical mechanism, the transistor 71 is also turned off. The voltage of the transistor 73 is applied to the base of the transistor 77 via a heifer 76 formed of a voltage follower operational amplifier. An extension current flows through the collector of transistor 77, which causes capacitor 78 to
is being charged. (-) input M of comparator 72
When the output voltage becomes lower than the reference voltage V ref of the (+) input terminal, the output of the comparator 72 becomes "H" and the transistor 73 is turned on. Then, the transistor 74 is turned off and the power to the trailing curtain magnet 31 is cut off, and as a result, the trailing curtain 34 runs.

The movement of the rear curtain 34 activates a mechanical mechanism and turns off the mirror switch 30 again. Since the shutter switch 33 is also off at this time, both inputs of the AND gate 79 become ``H'' for the first time, and the output also becomes ``H''.
becomes. As a result, the transistor 80 is turned on, and the motor 35 is energized and rotates.

When the shutter switch 33 is turned on again as the motor 35 rotates, the output of the AND gate 79 becomes "L", the transistor 80 is turned off, and the motor 35 is stopped.

Furthermore, after a certain period of time has elapsed, the output of the power supply timer 56 becomes low.
", and the transistor 57 turns off. At this time, if the release switch 51 is not on, the transistor 5
5 is turned off, the power supply to the circuit is cut off, and the original state is restored.

As described above, in the present invention, when the imaging device of an electronic camera is electrically scanned before and after photographing, the scanning frequency of the bare scan before photographing is set higher than the readout frequency of the readout scan after photographing, so that dark current It is possible to improve image quality by minimizing the negative effects of turbulence, and to perform high-speed photographing operations.

[Brief explanation of drawings]

FIG. 1 is a perspective view of essential parts showing an embodiment of the electronic camera of the present invention, FIG. 2 is a systematic connection diagram including the optical system, and FIG. 3 is a perspective view showing the vicinity of the quick return mirror and shutter. FIG. 4 is a time chart of the above embodiment, FIG. 5 is a block diagram showing an image sensor drive circuit, and FIG. 6 is a one-screen scanning circuit including elements 10...object, 11...photographing lens, 12...・Imaging device ('Image sensor), 13.
...Quick return mirror, 14...Finder optical system, 20...Image sensor drive circuit, 21...
- Exposure control circuit, 22... Photometric element, 25... Shutter, 26... Signal processing circuit, 27... Storage device,
28... Mirror magnet, 30... Mirror switch, 31... Rear curtain magnet, 33... Shutter switch, 35... Motor, 82... First oscillation circuit,
83... Second oscillation circuit, 86... Vertical drive pulse generation circuit, 87... Vertical synchronization signal generation circuit, 88...
Single screen scanning circuit. Patent applicant: Asahi Kogaku Kogyo Co., Ltd. Agent: Kunio Miura (Procedural amendment/approval ceremony) May 14, 1981 1. Indication of the case: 1988 Patent Application No. 6870 2. Name of the invention: Electronic camera 3. Relationship with the person making the amendment Patent applicant address 2-36-9 Maeno-cho, Itabashi-ku, Tokyo Name (
052) Asahi Optical Industry Co., Ltd. Representative Toru Matsumoto 6, Drawing 7 subject to amendment, Contents of amendment Figure 6 of the drawings will be amended to the attached drawing. 576-

Claims (1)

[Scope of Claims] (1) An imaging device that photoelectrically converts a subject image formed by a photographing lens, and an electric charge accumulated in the imaging device by electrically scanning the imaging device before and after photographing. In an electronic camera equipped with a scanning circuit that performs exposure and readout, and a storage device that stores the read image signals, the scanning frequency of the exposure scan before photography by the scanning circuit is equal to the scanning frequency of the readout scan after photography. An electronic camera characterized by being higher. (2. Claim 1 further includes: a shutter that controls the imaging light flux incident on the imaging device; an exposure control device that controls exposure via the shutter according to the brightness of the subject image; and an exposure control device that operates the shutter. and a quick return mirror that is normally located within the imaging light flux and guides the imaging light flux to the finder optical system, and at the time of photography, retreats from the imaging light path to provide the imaging light flux to the imaging device side. The start signal for readout scanning by the circuit is emitted by the electronic camera when the release switch is turned on. (3) In claim 1 or 2, the start signal for readout scanning by the scanning circuit is generated by the quick return mirror. An electronic camera that is emitted in synchronization with a detection signal for returning to the state before evacuation.