JP3907657B2 - Imaging device - Google Patents

Description

  The present invention relates to a photographing apparatus such as an electronic still camera.

  2. Description of the Related Art An electronic still camera that converts a subject image into an electrical signal using a solid-state imaging device and records the image on a recording medium is well known. As a recording medium for photographed image information, a small flexible magnetic disk was originally proposed, but after that, a device using a semiconductor memory due to an increase in the capacity of the semiconductor memory was also proposed. In recent years, a small-sized (less than 2 inch) hard disk device has been put into practical use and is also lightweight, and has attracted attention as an electronic still camera recording medium.

  As with conventional still cameras that use silver halide film as the recording medium, the electronic still camera has a single-shot mode that captures a single subject image with a single release operation, and the release button is held down. And a continuous shooting mode for continuously shooting subject images at predetermined time intervals.

  Since the amount of information recorded on one screen is relatively large, the transfer speed (write speed) to the final recording medium, which is a flexible magnetic disk, a solid-state memory device, or a hard disk device, depends on the image sensor and its output. Slower than the processing speed of the recording circuit. As means for substantially increasing the transfer speed, a configuration has been proposed in which a buffer memory capable of temporarily storing a plurality of pieces of photographed image information is provided in the middle, and the photographed image information in the continuous shooting mode is buffered.

  However, the electronic still camera must be easy to carry as an alternative to the conventional silver salt film camera, and it does not take up much space in the buffer memory and enlarge the camera. Can not. Although the degree of integration of the semiconductor memory has improved and a large-capacity semiconductor memory device can be obtained, if it is used in a large amount, the cost increases.

  Therefore, the capacity of the buffer memory must be reduced, but if the capacity of the buffer memory is not sufficient, the remaining recording capacity of the buffer memory becomes insufficient during continuous recording, and recording becomes impossible, reducing usability. Problem arises.

Therefore, an object of the present invention is to improve the usability of a photographing apparatus such as an electronic still camera .

One of the imaging apparatuses according to the present invention includes, for example, a storage unit that temporarily stores an image obtained by continuous shooting, and a writing unit that writes an image read from the storage unit to a recording medium. When the continuous shooting is continued, the image obtained by the continuous shooting is not displayed, but when the continuous shooting is stopped , the last shot among the plurality of images obtained by the continuous shooting is taken. display image, a first display mode that does not display the remaining image, further a second display mode for displaying a plurality of images obtained by the continuous shooting with a multi-screen, the first display One of the mode and the second display mode can be selected .

According to the present invention, usability of the photographing apparatus can be improved .

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a schematic block diagram of an embodiment of the present invention. 10 is a photographing lens, 12 is a light quantity control member such as an aperture and a shutter, 14 is an image sensor that converts an optical image into an electrical signal, and 16 is a sample and hold (S / H) circuit that samples and holds the output of the image sensor 14. , 18 is an A / D conversion circuit that converts the output of the S / H circuit 16 into a digital signal, and 20 is a recording processing circuit that performs recording processing such as compression and modulation on the output of the A / D conversion circuit 18.

  Reference numeral 22 denotes a buffer memory that stores the output of the recording processing circuit 20 in units of screens. For example, the semiconductor memory 24 is a memory control circuit that controls writing and reading of the buffer memory 22. In this embodiment, in order to facilitate understanding, the recording processing circuit 20 compresses the captured image by fixed-length encoding in which the amount of data after compression per screen is constant, and the buffer memory 22 Has 8 banks and can store compressed image information for a maximum of 8 screens as a whole.

  Reference numeral 26 denotes a final recording medium such as a hard disk device, and reference numeral 28 denotes an interface circuit for writing captured image information read from the buffer memory 22 by the memory control circuit 24 to the hard disk device 26. In addition to the hard disk device, a flexible magnetic disk drive device, an optical disk drive device, a magneto-optical disk drive device, and a solid-state memory device such as an EEPROM or a battery-backed DRAM may be used. As a solid-state memory device, a card-shaped memory card is known.

  Note that the writing speed to the buffer memory 22 in this embodiment is slower than the writing speed to the hard disk device 26. Therefore, the buffer memory 22 has a capacity corresponding to a plurality of screens and 8 screens. In addition, the present invention is effective if the final recording medium is a medium whose writing speed is slower than the writing speed of the temporary storage means.

  Even if the writing speed is not slower than the temporary storage means as the recording medium, the present invention is still effective if the processing speed of the processing circuit in the middle, for example, the processing speed of the information compression circuit is slower than the writing speed of the temporary storage means. is there.

  A system control circuit 30 controls the entire system. The system control circuit 30 is composed of a microcomputer, and the function can be expanded and changed by changing the operation program. Reference numeral 31 denotes a memory for storing various constants (thresholds V1, V2, V3, etc. described later) necessary for the operation of the system control circuit 30.

  A pulse generation circuit 32 supplies clock pulses necessary for driving to the image sensor 14, the S / H circuit 16, and the A / D conversion circuit 18 under the control of the system control circuit 30.

  Reference numeral 34 denotes a shooting standby switch for instructing the system control circuit 30 for shooting standby (photometry, colorimetry, focus control, etc.), and 36 denotes shooting (exposure of the image sensor 14 and reading out the charge signal thereof to the hard disk device. This is a photographing switch that instructs the system control circuit 30 to record. The shooting standby switch 34 and the shooting switch 36 are incorporated in a so-called release button. When the release button is pushed down to the middle, the shooting standby switch 34 is turned on. When the release button is pushed down to the end, the shooting switch 36 is turned on. It is supposed to become.

  Reference numeral 38 denotes an operating device for setting various operation modes such as single shooting mode and continuous shooting mode and inputting various instructions to the system control circuit 30. The operation device 38 includes a predetermined number of operation buttons or operation switches.

  The flow of image information in FIG. 1 will be briefly described. The optical image by the photographing lens 10 is incident on the imaging surface (photoelectric conversion surface) of the imaging device 14 by the light amount control member 12. The image sensor 14 converts the optical image into an electrical signal. The output of the image sensor 14 is sampled and held by the S / H circuit 16 and converted into a digital signal by the A / D conversion circuit 18. The recording processing circuit 20 performs recording processing such as white balance adjustment, compression processing, and modulation on the digital image signal output from the A / D converter 18, and the output is buffered under the control of the memory control circuit 22. The data is sequentially written in empty banks among the eight banks M0 to M7 of the memory 22.

  The memory control circuit 24 sequentially reads the data written in the buffer memory 22 according to the writing speed of the hard disk device 26 and supplies the data to the hard disk device 26 via the interface circuit 28. The hard disk device 26 sequentially stores data from the interface circuit 28. In this way, the compressed data of the photographed image is recorded on the hard disk device 26.

  FIG. 2 shows an operation flowchart of FIG. With reference to FIG. 2, the operation of this embodiment will be described. First, the operation when the continuous shooting mode is set by the operation device 38 will be described. In the continuous shooting mode, normally, while the shooting switch 36 is held in the on state, a continuous shooting state is set, that is, an operation state in which a subject is shot and recorded at regular time intervals.

  First, when the photographing standby switch 34 is turned on (S1), photographing standby operations such as exposure control, white balance adjustment, and focus adjustment are executed (S2). Thereafter, if the photographing switch 36 is not turned on (S3) and the photographing standby switch 34 is turned off (S4), it waits for the photographing standby switch 34 to be turned on again (S1). Even if the shooting switch 36 is not turned on (S3), it waits for the shooting switch 36 to be turned on while the shooting standby switch 34 is turned on (S4).

  When the photographing switch 36 is turned on (S3), when the continuous recording mode is set in the operation device 38, the system control circuit 30 uses the memory control circuit 24 to set the remaining capacity of the buffer memory 22 to a predetermined threshold value. It is checked whether it is V1 or more (S5). The threshold value V1 is stored in the memory 31 in advance. If it is V1 or more (S5), shooting is performed (S6). That is, the image sensor 14 is exposed, the charge signal is read, and written to the buffer memory 22 via the circuits 16, 18, 20, and 24. As described above, the data written in the buffer memory 22 is read in synchronism with the hard disk device 26, applied to the hard disk device 26 via the interface circuit 28, and written.

  When the continuous recording mode is not set by the operation device 38, recording is possible as long as the buffer memory 22 has a free space for one screen.

  After photographing (S6), the remaining capacity of the buffer memory 22 is checked (S7), and it is determined whether or not this is equal to the second threshold value V2. The threshold value V2 is smaller than the threshold value V1 and is a storage capacity value corresponding to one or several sheets.

  If the remaining capacity of the memory 22 is not equal to the second threshold value V2 (S7), while the shooting switch 36 is on (S10) without executing S5, shooting (S6) and checking of the remaining capacity of the memory 22 (S7) )repeat. That is, continuous shooting is performed. Meanwhile, if the photographing switch 36 is turned off (S10), the photographing switch 36 and the photographing standby switch 34 are checked again (S3, S4). If the photographing standby switch 34 is turned off (S4), the process returns to S1. .

  If the remaining capacity of the memory 22 is equal to the threshold value V2 (S7), the continuous shooting is stopped and the same operation as in the single shooting mode is performed. That is, it waits for the photographing switch 36 to be turned off (S8). After the photographing switch 36 is turned off, if the photographing standby switch 34 remains on (S9), the photographing switch 36 is turned on again. (S3), if the photographing standby switch 34 is off (S9), it waits for the photographing standby switch 34 to be turned on again (S1).

  When the remaining capacity of the memory 22 is less than the threshold value V1 (S5), it is checked whether or not the remaining capacity is zero (S11). When the remaining capacity is zero, if the shooting standby switch 34 is on (S13), the camera waits for the shooting switch 36 to be turned on (S3), and if the shooting standby switch 34 is off (S13), Wait until the switch 34 is turned on (S1). If the remaining capacity is not zero (S11), one shooting is performed (S12), and the camera waits for the shooting switch 36 to be turned off (S8).

  As can be seen from the above description, the threshold value V1 is a memory capacity corresponding to the remaining number of sheets that can be continuously shot at the start of continuous recording, and the threshold value V2 is a memory capacity corresponding to the remaining number of sheets for which continuous shooting is stopped. These threshold values V1 and V2 may be fixedly stored in the memory 31, or may be stored so as to be changeable by operating the operation device 38. The latter is convenient for use.

  If the remaining capacity of the buffer memory 22 is equal to or greater than V1, continuous shooting is permitted, and the continuous shooting is stopped when the remaining capacity of the memory 22 becomes equal to the threshold value V2 during continuous shooting. Single shooting is possible even if the remaining capacity of the buffer memory 22 is V2 or less, and if the transfer from the buffer memory 22 to the hard disk device 26 proceeds during that time, and the remaining capacity of the buffer memory 22 becomes equal to or greater than the threshold value V1. Again, continuous shooting is possible. Even if the remaining capacity of the buffer memory 22 is less than V1 at the start of shooting in continuous shooting mode, single shooting is possible as long as it is not zero.

  Thus, the effective number of images that can be continuously shot is determined by the difference between the writing speed of the buffer memory 22 and the writing speed of the hard disk device 26, and the threshold value V1. Even if continuous shooting becomes impossible, it is possible to perform single shooting, so there is no need to miss a shutter chance.

  FIG. 3 shows a flowchart of the changing operation of the embodiment shown in FIG. The same steps as those in FIG. 2 are denoted by the same reference numerals, and specifically, S20 to S23 are inserted between S6 and S7. In this modification example, the maximum number of continuous shots K is determined in advance. K can be changed by the operation device 38 and is stored in the memory 31. If the remaining capacity of the memory 22 reaches V2 before K sheets are continuously shot, the continuous shooting is stopped. After the continuous shooting of K sheets, the user is forced to cancel the continuous shooting by waiting for the photographing switch 36 to be turned off.

  Hereinafter, FIG. 3 will be described in detail. The process up to the first shooting (S6) is the same as in FIG. After the first shooting, it is checked whether or not the number of continuous shots has reached the set value K (S20). If it has not reached the set value K, it is determined whether or not the remaining capacity of the buffer memory 22 is equal to the threshold value V2. Check (S21). If it is equal to V2, the continuous shooting is stopped and the photographing switch 36 is awaited to be turned off (S8). If it is not equal to V2 (S21), the photographing is repeated while the photographing switch 36 is on (S22, S6, S20, S21). If the photographing switch 36 is turned off (S22), the photographing switch 36 is turned on again. It waits to become (S3).

  If the number of continuous shots is equal to the set value K (S20), it waits for the photographing switch 36 to turn off, and checks whether the remaining capacity of the memory 22 is equal to the threshold value V2 (S7). The steps after S7 are the same as those in FIG.

  By setting the upper limit value K for the number of continuous shots set in this embodiment to a level that covers the number of shots in normal continuous shooting, it is possible to prevent continuous shooting for an unnecessarily long time. Since the data stored in the memory 22 is transferred to the hard disk device 26 even after the continuous shooting is stopped once again, the data stored in the memory 22 is transferred to the hard disk device 26. Capacity increases. If the remaining capacity of the memory 22 is V1 or more, continuous shooting is possible.

  As can be easily understood from the above description, according to the present embodiment, since the continuous recording is stopped while leaving a predetermined amount of space in the temporary storage means, the image information is transferred from the temporary storage means to the final recording medium. In the meantime, the image information can be taken into the temporary storage means. That is, in the case of a still camera, single shooting is possible, and there is no need to miss a shutter chance.

  4 and 5 are flowcharts of still another change operation of the embodiment shown in FIG. In executing this flowchart, in the present embodiment, a plurality of continuous shooting speeds can be selected, and means for switching such continuous shooting speeds is provided. The operation will be described below.

  Next, an embodiment in which the predetermined amount is changed according to the continuous shooting speed will be described with reference to FIG. When the photographing switch 36 is turned on in FIG. 4 (S3), when the continuous recording mode is previously set in the operation device 38, the system control circuit 30 determines that the remaining capacity of the buffer memory 22 is reached via the memory control circuit 24. It is checked whether or not the predetermined amount is V1 or more (S5). If the predetermined amount V1 is equal to or greater than the predetermined amount V1 stored in the memory 31 in advance, it is checked whether the continuous recording mode is the high-speed continuous shooting mode (S6). If it is in the high-speed continuous shooting mode, the camera shoots (S7), waits for a predetermined time t1 (S8), and checks whether the remaining capacity of the memory is equal to or greater than the predetermined amount V2 (S9). If so (S10), shooting continues. That is, if the continuous recording mode in which continuous shooting is performed is the low-speed continuous shooting mode, shooting is performed (S12), waiting for a predetermined time t2 (S13), and whether the remaining capacity of the memory is equal to or greater than a predetermined amount V3 (S14) is determined. If the shooting switch 36 is on (S15), shooting continues. That is, continuous shooting is performed, where t1 <t2. That is, it is possible to perform continuous shooting at a higher speed when waiting for a predetermined time t1 and continuing shooting than when waiting for t2.

  In S9 and S14, when the remaining capacity of the memory becomes smaller than the predetermined amount V2 and the predetermined amount V3, the continuous shooting stop is displayed (S11). When the photographing switch 36 is turned off (S16), if the photographing standby switch 34 is on, the process proceeds to S3, and if it is off, the process proceeds to S1 (S17).

  If the remaining capacity of the memory is smaller than the predetermined amount V1 in S5, it is checked whether the remaining capacity of the memory is 0 (S18). If not, the image is taken and the process proceeds to S16. When it is 0, it is displayed that photographing cannot be performed (S20), and when the photographing switch 36 is turned off (S21), the process proceeds to S3.

  As can be seen from the above description, the predetermined amount V1 is the remaining memory capacity for continuous shooting, the predetermined amount V2 is the remaining memory capacity for stopping high-speed continuous shooting, and the predetermined amount V3 is the remaining memory capacity for stopping low-speed continuous shooting. In this embodiment, V2> V3. These predetermined amounts may be fixedly stored in the memory, or may be stored so as to be changeable by operating the operation device 38.

  Next, an example in which high-speed continuous shooting is automatically switched to low-speed continuous shooting when the remaining memory capacity reaches a predetermined amount will be described. In FIG. 5, S1 to S6 are the same as those in FIG. If the remaining capacity of the memory is larger than the predetermined amount V2, high-speed continuous shooting is performed in the same manner as in FIG. 4 (S7), and if it is small, the low-speed continuous shooting mode is displayed, that is, low-speed continuous shooting is displayed (S12). (S13), wait for a predetermined time t2 (S14), and when the remaining capacity of the memory becomes smaller than the predetermined amount V3 (S15), display of continuous shooting stop is displayed (S17).

  Here, the predetermined amount V1> the predetermined amount V2> the predetermined amount V3. That is, when the remaining memory capacity reaches the predetermined amount V2 during continuous shooting in the high-speed continuous shooting mode, the continuous shooting mode is automatically switched to the low-speed continuous shooting mode and continuous shooting is continued, and the remaining memory capacity reaches the predetermined amount V3. By the way, stop continuous shooting.

  FIG. 6 is a block diagram showing the configuration of the second embodiment of the present invention. In FIG. 6, reference numeral 40 denotes an interface for connecting the remote controller 24 and the monitor to display image data stored in the memory 22 on a monitor to be described later, 42 is a monitor for displaying an image, and 43 is to perform processing such as compression to be described later. DSP.

  This embodiment is an effective method when the time required for image compression of one image is longer than the continuous shooting interval. In the present embodiment, only the processing that can be executed in real time such as white balance adjustment and γ correction is performed in the recording processing circuit 20, and then the memory control circuit 24 stores the eight banks M 0 to M 7 in the buffer memory 22. Sequentially written to free banks.

  In single frame shooting, real-time processing such as WB and γ is performed, and after being written in the buffer 22, it is read again by the memory control circuit 24, and processing that requires processing time such as compression is performed by the DSP 43 ( For example, when a compression method such as JPEG compression is employed, the entropy code is obtained by temporarily holding the coefficient sequence after DCT in an empty area in the buffer 22 before entropy coding. The processing time when changing the compression rate according to the amount of data after conversion can be shortened). FIG. 7 shows a flowchart of the operation of the image recording apparatus having such a configuration.

  Details of the operation will be described below with reference to FIG.

  If the photographing standby switch 34 is on (S1), the photographing standby is performed (S2). Next, it is checked whether or not the remaining capacity of the memory is 0 (S3). If it is 0, a shooting impossible display is displayed (S4). If the shooting standby switch 34 is on, the process proceeds to S3. If the remaining memory capacity is not 0, the shooting impossible display is erased (S6), and if the shooting switch 36 is turned on (S7), the remaining memory capacity is checked (S9). Proceed to S10. When the process proceeds to S 11, if the photographing switch 36 remains on, photographing is continued and data is stored in the buffer memory 22. That is, continuous shooting is performed.

  When the flow branches from S9 to S10, the flow proceeds to S10, S15 and the subsequent single shooting. If the remaining memory becomes smaller than V2 when shooting is performed in step S11 (S12), the continuous shooting stop is displayed (S14). Next, data when the captured image data is compressed by the DSP 43, for example, all coefficient data of DCT processing, that is, data after orthogonal transformation is created (S15), and an empty area of the buffer memory 22, that is, after continuous shooting is stopped. Store in the remaining area (S16).

  Next, the orthogonally transformed data is quantized with a predetermined coefficient, Huffman coded (S17), the obtained data is recorded on the hard disk 26 (S18), the photographing switch 36 is turned off, and the data in the buffer memory 22 is stored. Until the data is processed and recorded on the hard disk (S19 to S21), the above-described S15 to S18 are executed. When the data in the memory 22 is processed, the flow branches from S21 to S22, the continuous shooting stop display displayed in S14 is deleted, and it is determined whether or not the shooting standby switch 34 is on (S23). If it is on, the flow returns to S3. If it is off, the flow returns to S1.

  Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 8 is a flowchart showing a modification of the operation of this embodiment.

  In this embodiment, a function for immediately reproducing and monitoring an image captured and recorded in the embodiment of FIG. 7 is added, and a series of images continuously captured in a buffer, with a predetermined remaining amount remaining, are displayed as a multi-image or By keeping it as a composite image, it is possible to monitor continuously shot images.

  The operation of this embodiment will be described below with reference to FIG. In FIG. 8, first, if the photographing standby switch 34 is on (S1), the photographing standby is performed and the final photographed image is directly displayed on the monitor from the memory control 24 without passing through the buffer memory 22 (S61).

  Next, it is checked whether or not the remaining capacity of the buffer memory 22 is 0 (S31). If the remaining capacity of the buffer memory 22 is not zero, the non-shootable display is deleted (S32). If the shooting switch 36 is turned on (S33), it is checked whether the remaining memory capacity is equal to or greater than the predetermined amount V1 (S35). If it is smaller than V1, single shooting is performed (S52), and it is displayed on the monitor (S67). If it is V1 or more, shooting is performed (S36).

  Next, it is checked whether or not the remaining memory capacity has reached a predetermined amount V2 (S7). If the shooting switch 36 is on instead of V2, the shooting continues (S10). When V2 is reached, continuous shooting is stopped (S8), and if the monitor display mode is the normal display mode (S61), the last shot image is reproduced from the buffer memory 22 and displayed (S67). If it is not the normal display mode, it is checked whether it is the multi-image mode or the composite image mode (S62), and if it is the composite image mode using the remaining capacity V2 of the buffer memory 22, a composite image is created (S63) and displayed on the monitor. (S64). In the multi-image mode, a multi-image is created using the remaining capacity V2 of the buffer memory 22 (S65) and displayed on the monitor (S66). This display is displayed while the shooting standby switch 34 is on. When the shooting standby switch 34 is turned off, the display is completely erased (S24) and the process proceeds to S1.

  In the present embodiment, the composite image mode combines one of the images stored in the memory 22 with an image that does not pass through the buffer memory 22, and again the remaining capacity in the buffer memory 22. This is a mode for recording in V2.

  The multi-image mode is a mode in which a plurality of images stored in the memory 22 are converted into a multi-image and recorded in the remaining capacity in the buffer memory 22.

  In S64, S66, and S67, the same flow as S15 to S23 described above with reference to FIG. 7 is executed.

  According to the above embodiment, various image editing can be performed with a simple configuration by effectively utilizing the capacity of the buffer memory, and the opportunity of image recording is not missed.

  Further, the image editing is not limited to the above-described example, and other editing, for example, enlargement or reduction of an image, italic type, or the like may be used.

  Various modifications can be made to the above embodiment within the scope of the claims.

1 is a configuration block diagram of a first embodiment of the present invention. It is a 1st operation | movement flowchart of FIG. FIG. 3 is a second operation flowchart of FIG. 1. FIG. 6 is a third operation flowchart of FIG. 1. FIG. It is a flowchart of the 4th operation | movement of FIG. It is a block diagram of the configuration of the second embodiment. It is a 1st operation | movement flowchart of FIG. FIG. 7 is a second operation flowchart of FIG. 6. FIG.

Claims (4)

Storage means for temporarily storing images obtained by continuous shooting;
Writing means for writing an image read from the storage means to a recording medium;
When the continuous shooting is continued, the image obtained by the continuous shooting is not displayed, but when the continuous shooting is stopped , the last shot image among the plurality of images obtained by the continuous shooting is displayed. displays, a first display mode that does not display the remaining images,
Further comprising a second display mode for displaying a plurality of images obtained by the continuous shooting with a multi-screen,
An imaging apparatus, wherein either the first display mode or the second display mode can be selected. The photographing device according to claim 1, characterized in that whether to stop the continuous shooting, determined in accordance with the remaining capacity of the storage means. When said continuous shooting stopped, imaging apparatus according to claim 1 or 2, characterized in that the image obtained by the continuous shooting stops next continuous shooting to be written to all the recording medium. The recording medium includes a photographing device according to any one of claims 1 to 3, characterized in that the hard disk apparatus.

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