JPH1070697A - Electronic still camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain a recording image of a desired shutter chance with almost zero delay time at image pickup by transferring and recording a video signal stored in a buffer means in response to the image pickup operation to a recording medium. SOLUTION: When a photographer depresses a release button deeply from a half-depression state of the release button through recognition of a shutter chance, a release signal is switched to an H level and a write inhibit signal of a buffer memory 7 is outputted as an H signal from a sequence control circuit 11 synchronously with a 2nd synchronizing signal generated after that. The video signal of a pattern whose charge storage is first finished is stored in a memory pack 10 from a CCD 3 via a process circuit 5 and an A/D converter 6 synchronously with a succeeding synchronizing signal generated after the charge storage operation is finished. The video signal of each pattern stored in the buffer memory 7 succeedingly is transferred and stored in the memory pack 10 succeedingly synchronously with the synchronizing signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electronic still camera for electronically recording a photographed still image.

[0002]

2. Description of the Related Art Conventionally, this kind of apparatus is composed of an image pickup unit for converting a photographed subject image into an electric signal, and a recording unit for recording the electric signal on a magnetic disk or a semiconductor memory. Further, as with this type of apparatus, a camera using a conventional silver halide photosensitive material has been widely used for still image shooting.

In these apparatuses, the photographing and recording operation is started by pressing a release member provided on the camera body, and a mode is set such that one screen is photographed each time the release member is pressed. In addition, there is a case where shooting in a continuous shooting mode in which a plurality of screens are sequentially shot at predetermined time intervals while the release member is being pressed is possible.

[0004]

However, in such a conventional camera, there is a slight time delay from when the release member is pressed until when information on the subject to be actually photographed is captured (imprinted). Was. The average delay time is about 100 msec, and even a short delay time is 300 msec.
It has a delay of about msec.

Further, in actual photographing, the biological reaction of the human body is delayed from the time when the photographer perceives a photo opportunity of the subject to the time when the release member is actually operated (0.05).
０．２0.2 seconds) is added to this. For this reason, when a delicate photo opportunity is required, such as when photographing a moving subject, the photographer performs the release operation at a slightly earlier timing in anticipation of these delay times, so that the photographer can obtain the photo opportunity. If the camera has a continuous shooting mode or a camera that has a continuous shooting mode, the actual situation is to take continuous shots before and after the desired photo opportunity and select the desired screen from among multiple shots. there were.

In these photographing methods, the photographer's skill and photographing skill are required to some extent, or a large number of screens that are not originally required are photographed in the continuous photographing mode, and the recording area of the video is wasted. It had drawbacks such as fear. In addition, it is very difficult to respond to a subject whose movement is difficult to predict, such as a child or an animal, or an irregularly moving subject, or a sudden photo opportunity.

The present invention has been made in view of such a conventional problem, and records a screen at a predetermined timing immediately before a photographer operates a release member to perform a photographing operation. It is an object of the present invention to provide an electronic still camera capable of easily obtaining a recorded image of an originally desired shutter chance with almost zero delay time.

[0008]

In order to achieve this object, the present invention is configured as follows. First, the present invention provides a photographing optical system, an image pickup unit for photoelectrically converting a subject image formed by the photographing optical system into a video signal, and a video signal obtained from the image pickup unit in response to the release signal generation to a recording medium. The present invention is directed to an electronic still camera having recording means for recording.

According to the present invention, there is provided an electronic still camera comprising: a buffer memory for temporarily storing a video signal obtained from an image capturing means; Means for storing the video signal obtained from the imaging means before the release signal is generated at a predetermined timing in the buffer memory means, and photographing by fully pressing the release button, etc. Control means for transferring and recording the video signal of at least one screen stored in the buffer memory means to the recording medium in accordance with an operation.

Here, the preliminary photographing means includes a timing setting means for setting a time interval for storing a new video signal for one screen in the buffer memory means, and a screen for transferring and recording from the buffer memory to a recording medium. A number setting means for setting the number is provided. According to the electronic still camera of the present invention having such a configuration, the video signal obtained from the imaging means is sequentially stored in the buffer memory in the shooting preparation stage before the release signal is obtained, and is released by the release operation of the photographer. When the release signal is obtained, the video signal for one or more screens stored in the buffer memory is transferred and recorded on the recording medium, so that the release signal corresponding to the delay time of the release operation of the photographer is generated before the release signal is generated. The video signal at the time point can be recorded on a recording medium, and even a beginner can easily capture and record a video of a desired photo opportunity.

In addition, since the cycle time of the operation of writing a new video signal into the buffer memory can be set arbitrarily, it is possible to respond to the skill, skill, and shooting conditions of the photographer in detail.

[0012]

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, an imaging unit 100
Is a photographing lens 1, an aperture 2, an image pickup device 3 such as a CCD, an image pickup device driving circuit 4 for controlling the operation of the image pickup device 3, a process circuit 5 for converting an output signal of the image pickup device 3 into a video signal, A / It is composed of a D converter 6 and the like.

The video signal A / D converted by the A / D converter 6 is stored in a buffer memory 7 and a recording unit 200.
Of the memory pack 10. The buffer memory 7 is constituted by a rewritable semiconductor frame memory such as a RAM element, and has a capacity capable of storing about three screens of a captured still image.

As shown in FIG. 2, the memory pack 10 is provided on the side of the camera main body so as to be detachable from the camera main body through the memory pack insertion hole 20 by operating the ejection knob 21. The recording of the video signal in the memory pack 10 can be performed both by direct recording of the output of the A / D converter 6 and transfer recording by reading and recording the signal once stored in the buffer memory 7. Pack 1
It has a capacity to record approximately 20 shot still images per image.

The buffer memory control circuit 8 and the recording control circuit 9 are circuits for controlling the writing and reading of digital video signals in the buffer memory 7 and the memory pack 10, respectively, and both respond to the signal output from the sequence control circuit 11. Works. In the present embodiment, the recording unit 20
0 is composed of a memory pack 10 using a semiconductor memory and its recording control circuit 9, but may be composed of a magnetic recording medium of a floppy disk and its drive control device.

The sequence control circuit 11 receives a switch input from an operation member of the camera, and outputs control signals to the image sensor control circuit 4, buffer memory control circuit 8, and recording control circuit 9 to control the operation sequence of the camera. I do. Half-press switch 12 and release switch 13
Is interlocked with the pressing operation of the release button 23 in FIG.
When the release button 23 is lightly pressed to approximately half of the full stroke, the half-press switch 12 switches from off to on, and when the release button 23 is pressed deeply to nearly the full stroke, the release switch 13 also switches from off to on.

On the outer periphery of the release button 23 shown in FIG. 2, a rotary operation type SC switching knob 24 is provided. The SC switching knob 24 is provided with an L (lock) mechanism for mechanically preventing the pressing operation of the release button 23, a single mode S for photographing one screen each time the release button 23 is pressed, and Continuous shooting mode (continuous mode) in which a plurality of screens are sequentially shot at predetermined time intervals during pressing
3 can be selectively set at three positions. S
The SC switch 14 in FIG. 1 is switched from off to on in conjunction with the switching of the -C switching knob 24 from the S position to the C position.

At the top of the finder window 22 of the camera,
Two rotary operating members, a timing setting dial 25 and a recording frame number setting dial 26, are arranged. The two setting dials 25 and 26 are respectively a timing setting switch 15 and a recording frame number setting switch 1 shown in FIG.
It is linked to 6. The timing setting switch 15 is a changeover switch for selecting a time interval at which the buffer memory control circuit 8 rewrites the image signal stored in the buffer memory 7 with a new image. The recording frame number setting switch 16 operates the buffer memory 7 during the release operation. Switch for setting the number of screens of still images to be transferred from the camera to the memory pack 10.

A liquid crystal display panel 27 disposed on the upper surface of the camera body displays photographing information such as the number of photographed (or remaining photographable) screens and various operating conditions. Next, the operation of the embodiment of FIGS. In the electronic still camera of this embodiment, the S mode for single frame shooting and the C mode for continuous frame shooting can be selected. First, the operation when the SC switching knob 24 is set to the S mode position will be described. I do.

Prior to photographing, the number of screens to be transferred and recorded from the buffer memory 7 to the memory pack 10 at the time of photographing is set to a desired value from 0 to 3 by a recording frame number setting dial 26. This set value is used to select the number of screens read into the buffer memory 7 immediately before the operation of the release switch 13 to be recorded in the memory pack 10. When 0 is selected, 1 screen after the operation of the release switch is operated.
The operation is the same as that of a conventional camera that records only the screen. Similarly, the timing of reading an image into the buffer memory 7 is set by the timing setting dial 25 using L, M, H, and SH.
Select one of The four settings L to SH set the time interval for reading the image to the buffer memory 7 to 100.
Select the length of time, such as msec, 50 msec, 33 msec, 17 msec, etc. For example, when the release timing is unstable such as a beginner, a long time setting is required especially when a delicate photo opportunity is required Can be set to a shorter time.

FIG. 3 is a time chart showing an example of the operation of the electronic still camera according to the present invention when the one-frame shooting S mode is selected. In the example of FIG. 3, the setting of the number of recording frames is 3, and the setting by the timing setting dial is 50.
The operation when each is set to msec will be described. When the photographer holds the camera toward the subject and presses the release button 23 lightly to the half-pressed position, the half-press switch 12 is turned on, and the half-press switch generated by the sequence control circuit 11 in response thereto. The signal changes from L (Low) to H (Hi)
gh), and a power supply circuit (not shown) that supplies power to the imaging unit 100 enters an operating state. After a predetermined period of time from when the output of the power supply circuit rises to a stable state elapses, the synchronization signal for controlling the operation timing of each part of the camera is reset. As this synchronization signal,
A vertical synchronizing signal of a video signal is suitable and generally used widely. In this embodiment, the period of the synchronizing signal is set to 1 /
Although it was set to 60 seconds, it is not necessarily limited to this.

Further, in response to the operation of the half-press switch 12, power is supplied to an exposure control circuit (not shown), and the aperture of the diaphragm 2 is controlled according to the output of the exposure control circuit. In this state, the accumulation of charges corresponding to the subject image on the image sensor 3 is started in synchronization with the vertical synchronization signal. In the present embodiment, a CCD is used as the image pickup device 3, and the charge accumulation time and the aperture of the CCD are controlled by the output of the exposure control circuit.
The configuration is such that a video signal having an appropriate output level can be obtained even when the brightness of the subject changes. The charge storage time of the CCD is equivalent to the shutter speed of the conventional camera. Instead of controlling the charge storage time, an electromagnetically driven mechanical shutter is provided in front of the image pickup device 3 and is similar to the conventional camera. The exposure time control may be performed.

CCD3 started in synchronization with the vertical synchronizing signal
The charge accumulation of the CCD 3 is stopped after a lapse of a predetermined accumulation time corresponding to a normal exposure time, for example, about 1/45 second in the example of FIG. 3, and in response to the first synchronization signal generated after the completion of the charge accumulation. Of the buffer memory 7 via the process circuit 5 and the A / D converter 6.
Store in the second memory area.

Further, during the half-pressing operation, the signal newly stored in the CCD 3 is sequentially stored in the next memory of the buffer memory 7 at a time interval set by the setting switch 15, for example, at every 50 msec in the example of FIG. It is stored in the area. As shown in FIG. 3, the images captured by the CCD 3 are stored in the first, second, and third memory areas of the buffer memory 7 in order of A, B, and C, respectively, and the fourth D
Thereafter, it is rewritten and stored in the oldest stored area among the already stored memory areas. That is, D is stored in the first area instead of A. In this state, release button 2
3 is released and the half-press signal returns to L again, or the release button 23 is pressed further deeply and the release switch 13 is operated, and the sequence control circuit 11
The release signal generated from is switched from L to H,
The process is continued until writing to the buffer memory 7 is prohibited.

In this embodiment, in order to simplify the operation, the CCD set by the timing setting dial 25 is used.
The time interval for each screen in which the charge is stored in the memory 3 and the signal is stored in the buffer memory 7 is selected to be an integral multiple of the period of the vertical synchronization signal. When an arbitrary value other than an integral multiple of the period of the synchronization signal can be set, the synchronization signal is reset, for example, every time a signal is stored in the buffer memory 7 for one screen. it can.

When the photographer perceives a photo opportunity from the half-pressed state of the release button 23 and depresses the release button 23 deeply, the release signal is switched to H, and a second signal generated after the release signal is switched. A write inhibit signal for the buffer memory 7 is output from the sequence control circuit 11 as an H signal in synchronization with the first synchronization signal. The video signal of the screen E, where charge accumulation ends first after the switching of the release signal to H, is synchronized with the next synchronizing signal generated after the end of the charge accumulation operation, from the CCD 3 to the process circuit 5, A / A. D converter 6
Are recorded in the memory pack 10 through Subsequently, the video signals of the D, C, and B screens stored in the buffer memory 7 are sequentially transferred and recorded to the memory pack 10 in synchronization with the synchronization signal. The number of screens read from the buffer memory 7 is based on the number selected by the recording frame number setting dial 26. When the number of screens 2 is selected, two screens of D and C are recorded, and If Equation 1 is selected, only D is recorded.

When the recording of the video signal of the predetermined number of screens to the memory pack 10 is completed, both the release signal and the buffer memory write inhibit signal are switched from H to L again to be ready for the next release operation. After this,
Release switch 1 from the half-pressed release button 23 position
By pressing again to the position where 3 operates, another screen can be continuously taken. As in the case of a conventional camera, even if the finger is released from the release button 23 and the half-press switch 11 is turned off, as in the case of the conventional camera, in case that the photographing operation is repeated after a short period of time,
The sequence control circuit 11 is configured so that the release signal is switched to L after the release signal is held in the H state for a fixed time of about 0 second.

As described above, the photographed image E immediately after the release member is actually operated is recorded in the memory pack 10 in the same manner as a normal camera, and further, 50 msec, 100 msec, and 150 msec before the screen E, respectively. D, C, and B, which are the screens at the time, are stored. As shown in the time chart of FIG. 3, assuming that there is a response delay time of about 100 msec between the time determined by the photographer and the time when the release switch 13 is actually operated, the C is very close to the desired photo opportunity. The screen and the screens before and after it are recorded.

When it is desired to further reduce the difference between the photographing determination time and the recording screen as compared with the example of FIG. 3, the time set by the timing setting dial 25 may be set to a small value. Is recorded only during the short period before the release signal is generated, and the desired screen may not be recorded. In order to cope with such a case, there is a method of increasing the number of recording screens in the memory pack 10 per one photographing. However, as an improvement of this embodiment, the buffer memory 7 is used.
Alternatively, the sampling time of the storage screen may be shortened, and every other image may be transferred and recorded to the memory pack 10 to record half the number of screens. That is, in the example of FIG. 3, only C and A are recorded. Further, by transferring and recording every third image, it is possible to reduce waste of the recording area of the memory pack 10 by recording only one-third of the sampled image.

Further, a mode setting means for not recording a screen after a release signal is generated, such as a screen E, may be added so that an unnecessary screen is not recorded at all. Next, the operation when the setting of the SC switching knob 24 is set to the C mode for continuous frame shooting will be described with reference to the time chart of FIG. Since the basic operation when the C mode is selected is the same as that in the S mode, only different parts will be described.

After the camera is pointed at the subject and the release button 23, which is a preliminary operation for photographing, is half-pressed, the operation from when the release operation is performed to when the release signal is generated is as follows.
This is the same as in the case of the S mode. The example of FIG. 4 shows a case where the speed of continuous frame shooting is 10 screens per second (shooting interval of 100 msec). The setting of the number of recording frames and the timing setting are 3 frames and 50 msec as in the example of FIG. Is shown.

In the C mode, while the release button 23 is depressed deeply and the switch 13 is kept on, it is general that the photographing can be continued continuously. In this embodiment, as shown in FIG. 4, the raise signal output from the sequence control circuit 11 is switched to H in response to switching of the release switch 13 to ON, and until the recording to the memory pack 10 is temporarily terminated. H
After that, the state is switched to L.

Up to this point, the operation is the same as in the case of the S mode. After that, while the release switch 13 is on, the release signal changes from L to H at every continuous photographing time interval (100 msec), and recording ends. Each time it is switched from H to L, it is output. On the other hand, the buffer memory write inhibit signal is the first H of the release signal as in the S mode.
The H signal is output in synchronization with the second synchronizing signal after the switching to, but after this, even if the recording to the memory pack 10 is completed, it is held at H while the release switch 13 is on. You. As a result, the memory pack 10 has a screen E in which the charge accumulation ends immediately after the release switch 13 is turned on, a screen D, C, and B at intervals of 50 msec and a screen 100 msec thereafter. G, I,
K,... Are recorded.

When the release button 23 is released and the release switch 13 is turned off again, if the release signal is L at that time, the next release signal is not switched to H and the buffer memory write inhibit signal Becomes L, and the continuous frame photographing is completed to be ready for the next photographing operation. If the release signal is H at the time when the release switch 13 is turned off, the release signal is held at H until the recording of the screen to be recorded on the memory pack 10 at that time is completed, and then switched to Low. It is ready for the next shooting operation.

In the embodiment shown in FIG. 4, the D, C, and B screens are recorded at 50 msec intervals before the release signal is generated. When the function is regarded as important, the screen before the release signal is generated may be recorded at the same interval as the time interval of the continuous frame photographing (screens C and A in the example of FIG. 4).

In both the S mode and the C mode, the screen stored in the buffer memory 7 is recorded at the time of the preliminary shooting operation (half-pressing of the release button) before the release signal is generated. For the rise of the output of the supplied power supply circuit and the reading of the image signal into the buffer memory 7, 0.1 to 0.2 is required until the release signal is generated.
It is desirable that the photographing preparatory operation be performed for about seconds.
In normal photographing, such a short preparatory operation for a short time poses almost no problem. However, in an emergency or the like, the preparatory operation time may be extremely short. So, to be able to deal with such a case,
When a release signal is generated in a state where the number of screens stored in the buffer memory 7 has not reached the set number of frames, the storage screen of the buffer memory 7 at that time and a normal screen after the release signal is generated are recorded. By configuring the sequence control circuit 11, the effectiveness of the camera according to the present invention can be enhanced.

It is also useful to display a warning on a display unit in the viewfinder or the like while the time for the preliminary shooting operation has not reached the predetermined time. As still another countermeasure, a configuration in which a release signal is generated after a predetermined time has elapsed even if the release switch 13 is turned on at a time when the time of the preliminary shooting operation is shorter than a predetermined value, or at a time shorter than the predetermined value. The sequence control circuit 11 may be configured to prohibit the generation of the release signal.

[0038]

As described above, according to the present invention, it is possible not only to easily capture and record an image of a desired photo opportunity, but also to combine various settings according to the skill of the photographer and the photographing conditions. Further effective photographing and recording can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an external configuration diagram of a camera body according to the present invention.

FIG. 3 is a time chart showing an example of an operation state when the embodiment of FIG. 1 is operated in an S mode for shooting one frame at a time;

FIG. 4 is a time chart showing an example of an operation state of the continuous frame shooting in the C mode according to the embodiment of FIG. 1;

[Explanation of symbols]

 1: photographing lens 2: aperture 3: imaging device (CCD) 4: imaging device driving circuit 5: process circuit 6: A / D converter 7: buffer memory 8: buffer memory control circuit 9: recording control circuit 10: memory pack 11 : Sequence control circuit 12: Half-press switch 13: Release switch 14: SC switch 15: Timing setting switch 16: Recording frame number setting switch 100: Imaging unit 200: Recording unit

[Procedure amendment]

[Submission date] August 4, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

According to the present invention, there is provided such an electronic still camera, wherein the buffer memory means for temporarily storing a video signal output from the image pickup means, and the recording means.
Release signal generating means for starting recording operation by
And the imaging hand in a shooting preparation stage before the release signal is generated.
The video signal obtained from the stage is stored in the buffer memory means.
In the preliminary photographing means for storing and the buffer memory means
Updating means for updating the stored video signal.
You. In addition, the preliminary photographing means is configured to output the video signal at predetermined intervals.
Is stored in the buffer memory. In addition, the buffer
The memory means can store video signals for a predetermined screen.
And the updating means stores a new video signal.
Then, the oldest video signal is deleted and updated.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

According to the electronic still camera of the present invention having such a configuration, video signals obtained from the image pickup means are sequentially stored in the buffer memory in a photographing preparation stage before a release signal is obtained. When the release signal is obtained by the release operation, Ba Tsu file so the video signal of one or more screens are stored in the memory is transferred and recorded on the recording medium, minute release signal corresponding to the delay time of the photographer's release operation A video signal before the occurrence can be recorded on a recording medium, and even a beginner can easily photograph and record a video of a desired photo opportunity. Also, buffer memo
Updating means for updating the video signal stored in the memory means
Requires the storage capacity of buffer memory means
Missing a photo opportunity without making it bigger
I will not do it.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction contents]

[0038]

As described above, according to the present invention, it is possible not only to easily capture and record an image of a desired photo opportunity, but also to combine various settings according to the skill of the photographer and the photographing conditions. Further effective photographing and recording can be performed. Also, the buffer memory means
Update means for updating the received video signal.
And the storage capacity of the buffer memory means is unnecessarily large.
Don't miss a photo opportunity without breaking
No.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masami Takahashi 1-6-3 Nishioi, Shinagawa-ku, Tokyo Nikko Oi Works Co., Ltd. (72) Inventor Masaki Isogai 1-3-6 Nishioi, Shinagawa-ku, Tokyo Stock (72) Inventor Norichika Hashino 1-6-3 Nishioi, Shinagawa-ku, Tokyo Nikon Oi Manufacturing Co., Ltd.

Claims (4)

[Claims] A photographing optical system; and an image pickup means for photoelectrically converting a subject image formed by the photographing optical system into a video signal.
In an electronic still camera having a recording unit for recording the video signal obtained from the imaging unit on a recording medium, a buffer memory unit for temporarily storing a video signal output from the imaging unit, and the recording unit Release signal generating means for initiating a recording operation according to the present invention, preliminary photographing means for storing a video signal obtained from the image capturing means in the buffer memory means in a photographing preparation stage before the release signal generation, and the preliminary photographing means And a control means for transferring and recording at least one video signal of at least one screen stored in the buffer memory means to the recording medium in response to generation of a release signal. An electronic still camera, comprising: 2. A new one is sequentially stored in said buffer memory means.
2. The electronic still camera according to claim 1, further comprising timing setting means for setting a time interval for storing a video signal for a screen. 3. The electronic still camera according to claim 1, further comprising a number setting means for setting the number of screens to be transferred and recorded from said buffer memory means to a recording medium. 4. The image processing apparatus according to claim 1, wherein the control unit selectively transfers and records the video signal of a part of the screens among the video signals of a plurality of screens stored in the buffer memory unit to the recording medium. The electronic still camera according to claim 1.