JP3144684B2 - Electronic still camera - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic still camera.

[Prior Art] In an electronic still camera that converts a captured image into an electric signal and records one of the images as a still image on a recording medium, there is a problem that a time delay in the operation of recording an image has been longer than before. It has become. In particular, when a magnetic recording medium such as a floppy disk is used as a recording medium, it takes a considerable amount of time to complete the image recording because it is necessary to perform operations such as rotating the floppy disk when recording an image. I was For this reason, it is impossible to perform so-called continuous shooting in which images are continuously recorded one by one.

In order to solve such disadvantages, for example, Japanese Patent Application Laid-Open
As disclosed in Japanese Patent Application Laid-Open No. 62674, a semiconductor memory having a small storage capacity but a short writing time of image information is provided inside the electronic still camera, and a photographed image report is temporarily recorded in the internal semiconductor memory, and thereafter the electronic still camera is used. There has been proposed an electronic camera that records image information stored in the internal semiconductor memory in an external memory provided separately from the electronic camera. With this configuration, an image when the photographer operates the shutter release button of the electronic camera can be recorded in the external memory.

Further, as disclosed in Japanese Patent Application Laid-Open No. 63-64485, the storage capacity of the light guide memory provided in the electronic camera is set to a capacity capable of storing image information for a plurality of frames. An electronic still camera capable of recording image information and supporting continuous shooting has also been proposed.

[Problems to be Solved by the Invention] However, even in the electronic still cameras disclosed in the above publications, the information is recorded on the recording medium only when the photographer operates the shutter release button of the electronic still camera. Image information. Note that the operation of the photographer operating the shutter release button is performed by the photographer viewing the subject and judging by the photographer. Therefore, there is a problem that the image information recorded on the recording medium may not always be an image desired by the photographer due to a delay in human operation when operating the shutter release button.
Also, in order to obtain a truly necessary image when a photographer does not know when a truly necessary image appears, conventionally, continuous shooting or continuous shooting with a video camera has to be performed. Did not get. In such a case, the majority of the film or videotape is unnecessary,
There is also a problem that the recording medium is wasted and that editing after photographing also takes time.

The present invention has been made in order to solve such problems, and it is possible to obtain an image desired by a photographer,
An object of the present invention is to provide an electronic still camera that does not waste a recording medium.

[Means for Solving the Problems] According to the present invention, one screen image information is supplied every predetermined time, and the image information always includes the image information supplied at the latest point in time. A rewritable and readable first storage unit for storing image information of a plurality of screens supplied within a time period, a switch operably provided by an operator, and the switch is operated. In this case, the image information of a set number of screens including the image information of one screen at the latest time stored in the first storage unit can be written for each screen in time sequence from the image information, Second to store readable
And a control unit for the first storage unit that determines the set number of the image information stored in the second storage unit from the first storage unit.

[Operation] The first storage unit converts the image information of one screen, which is converted into an electric signal and supplied at predetermined time intervals, from the time at which the latest image information is supplied to the image data supplied at the latest time. It stores image information of a plurality of screens supplied within a predetermined period of time that goes back in time sequence. When the photographer operates the switch, the second storage unit includes a plurality of screens including the image information supplied to the first storage unit at the time when the switch is operated and including the image information and going back in time order from the image information. Is stored for each screen. Therefore, even when the photographer operates the switch late, the image information for a predetermined number of screens that is temporally retroactive from the time when the switch was operated is stored in the second storage unit. The electronic still camera operates so that the photographer can obtain a desired image from the second storage unit.

Since the image information supplied to the second storage unit is the image information for a predetermined number of screens supplied from the first storage unit, the present electronic still camera reduces the storage capacity of the second storage unit. It works so as not to waste it.

[Embodiment] In FIG. 1 showing an embodiment of the electronic still camera according to the present invention, a photographed image passing through a photographing lens 1, a shutter 2 and the like is formed and a light amount is converted into an electric signal. The image pickup device 3, which is formed of, for example, a CCD, in which accumulation and takeout are performed, is an analog-to-digital converter (hereinafter, A / D converter).
D converter 5) is connected to a digital signal processing unit 6 for creating an image digital signal conforming to the standard television system. A drive unit 4 is connected to the image pickup device 3, and the drive unit 4 controls the operation of all components constituting the present electronic still camera by controlling a system control unit 10 so that the image pickup device 3 can take a photographed image. The operation of the image sensor 3 is controlled so that the converted electric signal can be stored and extracted at each timing time Δt. Therefore, under the control of the drive unit 4, the image sensor 3 sends image information of one image formed of an electric signal to the digital signal processing unit 6 at every Δt time.

The shutter 2 is operated by a control signal sent from the system control unit 10, and is constantly driven so that an image can be taken every Δt. A switch 13 is connected to the system control unit 10, so that the fact that a subject desired by the photographer has appeared can be input to the system control unit 10.

The shutter 2 is not limited to the mechanical shutter as in the present embodiment, but may be an electric shutter in which the image sensor and its drive unit have functions of resetting image data and starting to capture image data.

The output side of the digital signal processing unit 6 is connected to a compression unit 7 that performs compression processing of the image digital signal by, for example, Hadamard transform, and the compression unit 7 is a semiconductor memory that can write and read the compressed image digital signal. Is connected to the internal memory 8.

The internal memory 8 is composed of a plurality of frame memories so that one frame of image information composed of the compressed image digital signal can be stored for a plurality of frames.
In this embodiment, eight frame memories are used as shown in FIG.
It is composed of M0 to M7. Such an internal memory 8
Converts the image digital signal supplied from the compression unit 7 in synchronization with the time Δt at which the image information composed of the electric signal is transmitted from the image sensor 3 into the frame memories M0 to M3.
Store them sequentially in M7. For example, as shown in FIG. 2, an image digital signal for one frame at time T0 is stored in a frame memory M0, and a time t0 is stored in a frame memory M1.
The image digital signal for one frame at time t1 at which time Δt has elapsed is stored, and similarly, at time t7 at the time when 7 × Δt has elapsed from time t0 in frame memory M7.
Is stored for one frame. Then, the image digital signal for one frame at time 8 at which the time Δt has elapsed from time t7 is stored again in the frame memory M0.
The image digital signal for one frame in is erased. The operation at the subsequent time is the same.
Therefore, the internal memory 8 stores the Δt in the direction in which the most recently supplied image digital signal starts from
Eight frames of image digital signals supplied every time are stored. Note that the number of frame memories provided in the internal memory 8 is not limited to the above number, but can be set arbitrarily. .

Further, the internal memory 8 includes a control unit for selecting a predetermined number of frame memories in the internal memory 8 by a control signal supplied from the system control unit 10 when the photographer operates the switch 13 to the ON state. 9 is connected.

Such an internal memory 8 is provided via a connection terminal 14a to an external memory 12 which is provided separately from the electronic still camera and is detachable from the electronic still camera. Also, the output side of the system control unit 10 is connected, and the external memory drive unit 11 that writes the image digital signal read from the frame memory selected by the internal memory control unit 9 to the external memory 12
Is connected to the external memory 12 via the connection terminal 14b.

Note that the external memory 12 is a C-MOS RAM which is a writable and readable memory usually composed of C-MOS transistors.
IC is used.

The electronic still camera body is formed of the above-described components except for the external memory 12.

The operation of the electronic still camera configured as described above will be described below.

The image sensor 3 sends to the digital signal processor 6 one frame of captured image information that has been converted into an electric signal every time Δt by the timing signal sent by the drive unit 4. The image information supplied to the digital signal processing unit 6 is processed into a signal conforming to the standard television system at each time Δt, and the data is compressed by the compression unit 7. The image digital signal for one frame that has been data-compressed in this way takes the same time Δt as the timing when the image sensor 3 sends out image information.
Each time, the data is sent from the compression unit 7 to the internal memory 8 by one frame, and is sequentially stored in each of the frame memories M0 to M7 as described above. After the image digital signal is stored in the frame memory M7, the internal memory 8 returns to the frame memory M0 again, deletes the previously stored image digital signal, and stores the currently supplied image digital signal. As described above, the internal memory 8 has a maximum of 7 × Δt among a plurality of image digital signals supplied at every Δt time starting from the image digital signal which is normally stored except for the start of the operation.
The image digital signal stored before the time is stored.

In the state where the image digital signal is stored in the internal memory 8 as described above, for example, when the photographer operates the switch 13 that operates in conjunction with the shutter release button at time t10, the system control unit 10 Upon detecting this, the system controller 10 sends a control signal to the internal memory controller 9. As shown in FIG. 2, the internal memory control unit 9 starts from the frame memory M2 to which the image digital signal has been supplied from the compression unit 7 at time t10, and sends the image data to the internal memory control unit 9 in advance in a direction going back in time. Frame memories for the set number of frame memories ΔM are selected. still,
The value of the number of frame memories ΔM is freely settable. If, for example, the above-mentioned ΔM is set to 4, the internal memory control unit 9 sets the frame memories M2 and M2 as shown in FIG.
Select 1, M0, M7. The internal memory 8 stores the frame memories M7, M0, M1, and M2 selected by the internal memory control unit 9.
Read out the image digital signal stored in the. The read image digital signal is written to the external memory 12 in accordance with a control signal sent from the external memory drive unit 11.

As described above, the image information for one frame at regular time intervals from the time when the photographer operates the switch 13 to the time that is a predetermined time before the time can be obtained from the external memory 12. Even when an image temporally later than the desired image is stored in the external memory 12 as the latest image information due to human factors, the photographer can obtain the desired image from the image information stored in the external memory 12. Can be.

The image digital signals stored in the plurality of frame memories in the internal memory 8 are sequentially replaced by new image digital signals to be supplied, and the image digital signals sent from the internal memory 8 to the external memory 12 are captured. The image digital signal at the time when the user operates the switch 13 is the top and the time Δ
Since the predetermined number of frames is designated by the internal memory control unit 9 out of the image digital signals stored for each t, the recording medium is not wasted. In particular, when performing continuous shooting, a large effect can be obtained without wastefully consuming a large amount of recording medium as in the related art.

[Effects of the Invention] As described above in detail, according to the present invention, the image information of a plurality of screens including the image information at the time when the photographer operates the switch and being retroactively sequenced from the image information is referred to as the second image. By being stored in the storage unit, for example, even when the switch operation of the photographer is performed after the desired image appears, the photographer can perform the second operation.
A desired image can be obtained from the storage unit. Also, the second
Since the number of screens of the image information stored in the storage unit is a predetermined number of screen information from the image information of the screen at the time when the photographer operated the switch, the recording medium is not wasted. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing the structure of the electronic still camera of the present invention, FIG. 2 is a diagram showing the structure and operation of the internal memory shown in FIG. 1, and FIG. 3 is an external memory rather than the internal memory shown in FIG. FIG. 9 is a diagram showing the transfer of information to the server. 7: compression unit, 8: internal memory, 9: internal memory control unit, 10: system control unit, 12: external memory, 13: switch.

Claims (1)

(57) [Claims] An image information of one screen is supplied every predetermined time, and a plurality of image information supplied within a predetermined time including the above-mentioned image information always supplied at the latest point in time are sequentially returned from the latest image information. A rewritable and readable first storage unit for storing image information of a screen, a switch operably provided by an operator, and a first storage unit when the switch is operated A second screen image information of a set number of screens including the image information of one screen at the latest time point stored in the image information and being set back in time order from this image information in a writable and readable manner for each screen. An electronic still camera, comprising: a storage unit; and a first storage unit control unit that determines the set number of the image information stored in the second storage unit from the first storage unit. .