JPH10136302A - Digital video camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate access to still images and the management of the still images by separating dynamic images and the still images and recording them in different media. SOLUTION: At the time of turning to a recording mode and starting recording, a CCD 12 passes object images through a video signal processing circuit 14, compresses them in a recording system digital signal processing circuit 16, obtains the digital video signals of a digital VCR format, encodes them in a digital modulation circuit 18 and then, records the dynamic images on a video tape 24 by a signal recording circuit 20. Also, while recording the moving images, by the pressing of a photo shot trigger button, a system controller 40 supplies a photo shot command to a microcomputer 38 for memory control and the microcomputer 38 instructs the write of the digital video signals for one frame to a semiconductor memory 36 and stores still image data in the memory 36. In such a manner, since the dynamic images are recorded on the tape 24 and the still images are recorded in the memory 36, the access to the still images is facilitated. Also, since they are taken out from the memory 36 to a personal computer 44 as the digital signals as they are, the display still image quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video camera, and more particularly to a digital video camera for recording, for example, a digital video signal of a subject on a video tape.

[0002]

2. Description of the Related Art In a conventional digital video camera of this type, when a photo shot trigger button is pressed for the purpose of photographing a still image, a video tape is driven at that timing, and an ID (identification signal) is transmitted together with a recorded digital video signal. ) Was recorded. Therefore, by detecting the ID, only the still image can be displayed on the monitor.

[0003]

However, in such a conventional technique, it is necessary to fast-forward the video tape to detect the ID in order to display a still image, and there is a problem that the display is troublesome. . Therefore, a main object of the present invention is to provide a digital video camera capable of easily displaying a captured still image on a monitor.

[0004]

SUMMARY OF THE INVENTION The present invention provides a generating means for generating a digital video signal of a subject, a recording means for recording the digital video signal on a video tape, an output means for outputting a still image recording instruction, and a still image. The present invention is a digital video camera comprising a writing means for writing a digital video signal for a predetermined frame into a memory in response to a recording command of the digital video camera.

[0005]

When the operator presses, for example, a photo shot trigger button during shooting, a photo shot command is given from, for example, a system control microcomputer (system controller) to, for example, a memory control microcomputer, whereby a digital video signal for one frame, for example, is stored in the memory. Written. That is, the digital video signal is continuously recorded on the video tape. For example, when the photo shot trigger button is pressed, the digital video signal for one frame at that time is written to the memory.

[0006]

According to the present invention, since a digital video signal for one frame, that is, a still image, is stored in the memory, a desired still image can be easily accessed at the time of reproduction. When a digital video signal is output to a monitor TV, it is necessary to convert the digital video signal into an analog signal once. However, since the digital video signal can be recorded in a memory as it is, the image quality of a still image transferred to a personal computer for display is improved. Can be done. Furthermore, since the moving image and the still image are recorded on different media, the management of the still image data becomes easy. Furthermore, since a signal having the same format as the digital video signal to be recorded on the video tape is written in the memory, the circuit up to the generation of the digital video signal can be shared, and the cost can be reduced.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the accompanying drawings.

[0008]

Referring to FIG. 1, a digital video camera 10 of this embodiment includes a system control microcomputer (syscon) 40. When the operator selects the recording mode with the mode selection switch and presses the recording start / pause button once, the system controller 40 issues a moving image recording instruction. Therefore, the CCD 12 generates a camera signal of the illuminated subject image and supplies the camera signal to the video signal processing circuit 14. The video signal processing circuit 14 converts the camera signal into
A video signal is generated by double sampling, the gain of the video signal is automatically adjusted, and the video signal with the adjusted gain is converted into a digital signal. The video signal that has been subjected to such processing is shuffled and compressed by the recording digital signal processing circuit 16, whereby a digital video signal in a digital VCR format is obtained.

The digital video signal is then encoded by a digital modulation circuit 18 and the encoded data is recorded on a video tape 24 by a signal recording circuit 20. Since the video tape 24 runs at a predetermined speed when the recording start / pause button is pressed, encoded data of a moving image is sequentially recorded on the video tape 24. When the recording start / pause button is pressed again, the recording operation is paused.

When the operator switches the mode selection switch to the reproduction mode, switches the medium selection switch to the tape side, and presses the reproduction button, the video tape 24 runs, and the signal reproduction circuit 26 reproduces the encoded data recorded. Reproduce. The digital demodulation circuit 28 generates a digital video signal by decoding the reproduced encoded data, and supplies the digital video signal to the reproduction-system digital signal processing circuit 30. In the reproduction system digital signal processing circuit 30, the digital video signal is expanded and deshuffled, and the deshuffled video signal is supplied to the monitor 34 via the D / A converter 32. As a result, video tape 2
4 is displayed on the monitor 34. If the operator presses the stop button during playback, the system controller 40 stops the playback operation.

When an external semiconductor memory 30 is mounted and the operator presses a photo shot trigger button during recording of a moving image, the system controller 40 gives a photo shot command to the memory control microcomputer 38. Therefore, the memory control microcomputer 38 is connected to the semiconductor memory 36.
To write a digital video signal for one frame. As a result, the still image data is stored in the semiconductor memory 36.

On the other hand, when the operator selects the reproduction mode and switches the medium selection switch to the memory side, the system controller 40 supplies a reproduction command to the memory control microcomputer 38. Therefore, the memory control microcomputer 38 reads, for example, the first still image data from the semiconductor memory 36 and supplies the data to the reproduction digital signal processing circuit 30. Therefore, a still image is displayed on the monitor 34. Thereafter, when the operator operates an image selection button composed of a + button and a-button, the system controller 40 gives an image switching command corresponding to the operation to the memory control microcomputer 38. Thus, the still image data read from the semiconductor memory 36 is switched, and the display on the monitor 34 is also switched.

On the other hand, when the personal computer 44 is connected to the digital video camera 10 through the interface 42,
The memory control microcomputer 38 invalidates the command from the system controller 40 and executes the command from the personal computer 44. Therefore, when still image data and its recording command are given from the personal computer 40, the memory control microcomputer 38
Writes the still image data into the semiconductor memory 36. When a still image reproduction command is given from the personal computer 40, the memory control microcomputer 38 reads out desired still image data. Therefore, the monitor 34 or the personal computer 4
4 displays a still image.

When the power of the digital video camera 10 is turned on, the memory control microcomputer 38 first processes the flowchart shown in FIG. 3 to initialize the semiconductor memory 36 and initialize the system controller 40. That is, first, it is determined whether or not the semiconductor memory 36 is connected in step S1, and if "NO", the connection error data is stored in the internal memory 38a in step S3. And step S
At 13, the connection error data is transmitted to the system controller 40. On the other hand, if "YES" in the step S1, it is determined in a step S5 whether or not the semiconductor memory 36 is initialized, that is, whether or not the semiconductor memory 36 has a predetermined format. Here, the predetermined format is a format as shown in FIG. That is, the semiconductor memory 3
6, a memory management data area and an image data area are formed. The image data area is divided into 24 data areas with the size of a digital video signal for one frame. In the memory management data area, the number of shots (number of stored images), the number of images that can be shot (data of the number of images that can be stored), the start address of each data area, and the still image Whether or not data is recorded, whether or not still image data is protected, and shooting time data are stored.

If it is determined in step S5 that the semiconductor memory 36 is in a predetermined format, the memory control microcomputer 38 stores the number of shots data, the number of shootable images, and the still image data in steps S7 to S11. The head address of the empty area that has not been detected is detected, and those data are stored in the internal memory 38a. Then, in step S13, the stored data is transmitted to the system controller 40. Therefore, the system controller 40 displays the number of captured images and the number of images that can be captured on the display panel 46.

If it is determined in step S5 that the semiconductor memory 36 is not in a predetermined format, the memory control microcomputer 38 sends format error data to the system controller 40 in step S15. Then, Syscon 4
0 indicates this on the display panel 46 to alert the operator. When the operator presses the format execution button in response to this, the system controller 40 gives a format execution command to the memory control microcomputer 38. Since the memory control microcomputer 38 checks whether or not the format execution command is given in step S17, when the command is given, the semiconductor memory 36 is set in a predetermined format in step S19 and the process returns to step S5. Therefore, at this time, the number of captured images displayed on the display panel 46 is 0, and the number of images that can be captured is 24.

The memory control microcomputer 38 processes the flow chart shown in FIG. 3 by a timer interrupt even after the power is turned on. In parallel with this, the memory control microcomputer 38 executes the flow chart shown in FIGS. 4 and 5 by a timer interrupt. And controls writing and reading of the semiconductor memory 36. That is, first, it is determined whether or not a photo shot command has been received from the system controller 40 in step S21, and if "YES", in step S23,
The head of the frame of the digital video signal is detected. Subsequently, in step S25, a digital video signal for one frame, that is, still image data, is written into the empty area with reference to the head address of the empty area stored in the internal memory 38a. Thereafter, in step S27, the memory management data and the data stored in the internal memory 38a are updated.
More specifically, the number-of-shots data is incremented and the number-of-shootable-images data is decremented, and the presence or absence of an image is set to “present” in the management data of the area where the still image data is written, and the shooting time is written. Also, the number of shots data stored in the internal memory 38a,
The data of the number of shootable images and the start address of the empty area are also updated. Then, in step S29, the updated storage data is transmitted to the system controller 40. Thus, the number of photographed images and the number of photographable images displayed on the display panel 46 are updated.

On the other hand, if "NO" in the step S21, the personal computer 4 is connected to the interface 42 in a step S31.
4 is connected or not, and if "YES",
In step S33, a command from the personal computer 44 is executed. Specifically, when a recording command and still image data are given, the still image data is written, and when a playback command is given, desired still image data is read. At this time, the command from the system controller 40 is invalidated.

If "NO" in the step S31, it is determined whether or not a reproduction command is received from the system controller 40 in a step S35. If "YES" here, the still image data stored in the first area is read in step S37, and it is determined whether the protect command and the erase command are received from the system controller 40 in each of steps S39 and S47. Here, "NO"
If so, the process is terminated. However, if a protect command is received, the still image data currently output from the monitor 34 is protected in step S41. That is,
The presence / absence of protection in the currently output still image management data is set to “Yes”. On the other hand, when the erase command is received, the currently output still image data is deleted in step S49, and the memory management data and the data stored in the internal memory are updated in step S51. That is, the number-of-shots data and the number-of-shootable-images data in the memory management data area and the internal memory 38a are updated, the presence or absence of an image in the management data is set to “none”, and the head address of the free area of the internal memory 38a is updated.

If "NO" in the step S35, it is determined whether or not an image switching command is received from the system controller 40 in a step S43. If "YES", image data corresponding to the command is read out and the process proceeds to a step S39. The process proceeds to step S21 if “NO”. That is, when the + button is pressed, the still image data next to the currently displayed still image is read, and when the − button is pressed, the still image data before the currently displayed still image is read.

According to this embodiment, since a moving image is recorded on the video tape 24 and a still image is recorded on the semiconductor memory 36, access to the still image is facilitated. Also, the digital video signal is displayed on the monitor 34 after it is once converted to an analog TV signal. However, the digital signal can be taken out from the semiconductor memory 36 to the personal computer 44 as it is, thereby improving the image quality of the still image displayed on the personal computer. Can be done. Furthermore, since the moving image and the still image are recorded on different media, the management of the still image becomes easy. Further, the digital video signal of the digital VCR format is transmitted to the video tape 24 and the semiconductor memory 3.
6, the CCD 12, the video signal processing circuit 14, and the recording digital signal processing circuit 16 can be shared, and the cost can be reduced.

Incidentally, as the semiconductor memory 36 of this embodiment, a compact flash memory or a solid state floppy disk is used.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is an illustrative view showing a semiconductor memory;

FIG. 3 is a flowchart showing a part of the operation of the embodiment in FIG. 1;

FIG. 4 is a flowchart showing a part of the operation of the embodiment in FIG. 1;

FIG. 5 is a flowchart showing a part of the operation of the embodiment in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Digital video camera 16 ... Recording system digital signal processing circuit 36 ... Semiconductor memory 38 ... Memory control microcomputer 40 ... Syscon

Claims (1)

[Claims] 1. A generating means for generating a digital video signal of a subject, a recording means for recording the digital video signal on a video tape, an output means for outputting a still image recording instruction, and a response to the still image recording instruction A digital video camera, comprising: writing means for writing the digital video signal for a predetermined frame into a memory.