JP2994683B2 - Still image playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still image reproducing apparatus, and more particularly to an apparatus for reproducing a still image from a tape-shaped recording medium in which a still image is recorded on a plurality of helical tracks per screen. It is about.

[Related Art] Generally, recording and reproduction of still image information does not have a temporal restriction as in the case of recording and reproduction of a moving image. Therefore, by providing at least one screen of memory, digital recording and reproduction at a low bit rate can be achieved. Recording and reproduction can be performed in the device. As an example of such an apparatus, an apparatus for recording and reproducing an audio rate digital signal on a tape-shaped recording medium with a rotating head is an apparatus for recording a still image of one screen in several seconds, that is, for several hundred tracks. Has been proposed. For example, Japanese Patent Application No. 60-276124 filed earlier by the present applicant discloses such an apparatus.

By the way, in this type of apparatus, since a very large number of still images are recorded on one tape, its search function is important. Various search methods are conceivable.For example, a number is assigned to each still image or each still image recording area on the tape-shaped recording medium, and this number is recorded on the recording medium as address information. The address information is reproduced while the tape is transported at a high speed, and a method of searching for a desired still image is conceivable.

[Problems to be Solved by the Invention] However, considering that such a method is applied to the still image reproducing apparatus as described above, when address information corresponding to the number of a still image to be reproduced is reproduced, normal reproduction is performed. Is started, all the still image information cannot be reproduced. This is because it has already passed the track of the area where the still image is recorded.

In order to solve this, after the desired address information is reproduced, an operation of temporarily rewinding or advancing the tape is required, which requires an extremely troublesome process for the operator.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a still image reproducing apparatus that allows an operator to quickly reproduce a desired still image with a simple operation.

[Means for Solving the Problems] Under such an object, according to the present invention, a still image signal for a plurality of screens is recorded from a tape-shaped recording medium in which a plurality of helical tracks are recorded per screen. In an apparatus for reproducing signals, address information reproduction for reproducing address information recorded on a plurality of helical tracks in an area where a still image signal of each screen of the tape-shaped recording medium is recorded and indicating the number of each area, Means for inputting desired address information, and in a search mode for reproducing the address information from the plurality of helical tracks while transporting the tape-shaped recording medium at a speed higher than a predetermined speed, address information reproducing means. When the address information reproduced in step 1 matches the number of an area adjacent to the area where the desired address information is recorded, the tape The normal recording mode is adopted in which the recording medium is transported at the predetermined speed and the still image signal is reproduced from each track.

[Operation] With the above-described configuration, it is possible to perform playback in the normal playback mode from a still image recorded in an area corresponding to the address information of a desired still image in the search mode, and perform a cumbersome operation. It has become possible to quickly reproduce a desired still image without the need.

[Examples] Hereinafter, the present invention will be described using examples.

FIG. 1 is a block diagram showing the configuration of a digital still picture recording / reproducing apparatus according to an embodiment of the present invention. FIG. 2 shows a recording format on a tape by the apparatus shown in FIG.

In FIG. 1, T is a magnetic tape, and Ha and Hb are 360
These rotating heads rotate at 0r.pm and have different azimuth angles. The tape T is guided along a rotating member 17 having rotating heads Ha and Hb over a predetermined angular range (approximately 120 degrees in FIG. 1). Ca is a capstan for conveying the tape T in the longitudinal direction, and 53 is a capstan.
This is a capstan control circuit that controls the capstan Ca in accordance with a command from the MPU 51.

13 is a switch connected by the MPU 51 to the R side during recording and to the P side during reproduction. 15 is the a side when the head Ha is tracing on the tape T, and the b side when the head Hb is tracing on the tape T. Switch, connected to, 61 is a timer, 63
Is the shutter release key, 65 is the format key, 67
Is a reproduction key for instructing normal reproduction, 69 is a search key for instructing a search, 71 is a numeric keypad for designating an address, and 73 is a stop key.

In the apparatus of the present embodiment, the tape-shaped recording medium is divided into a number of sectors in the longitudinal direction, and a still image signal for one screen can be recorded for each sector.

First, the sector division operation, that is, the formatting operation will be described.

When the format key 65 is operated with the tape T rewound, the MPU 51 causes the sector code generation circuit 31 to generate sector codes for several tracks. Here, the contents of the sector code include sector number information indicating the number of an area divided by each sector. This sector code is recorded in sector code areas indicated by SC1, SC2, and SC3 in FIG. A few tracks are enough for the sector code area.

When recording to one sector code area starts, MP
U51 resets the timer 61, and after this predetermined period τ, records the sector code in the next sector code area. This operation is repeated until the end of the tape, thereby completing the formatting.

FIG. 3 is a flowchart for explaining the operation of the microprocessing unit (MPU) 51 in FIG. 1, and the operation at the time of recording, reproducing, and searching will be described below according to this flowchart.

First, the operation at the time of recording will be described. When the power switch (not shown) is turned on, the flow of FIG. 3 starts,
First, the capstan control circuit 53 causes the tape T to be transported in the forward direction at a predetermined speed (step S8). And
The rotation heads Ha and Hb are set to the reproduction state, and the sector code is extracted by the sector code separation circuit 35. Then head H
The reproduced signals a and Hb are supplied to the sector code separation circuit 35 via an ECC decoder described later on the P side of the switches 15 and 13.

When the MPU 51 detects that the heads Ha and Hb are tracing the sector code area from the sector code from the sector code separation circuit 35 (step S9), the tape T
Is stopped (step S10), and the operation standby state is established. In this way, recording and reproduction described later are performed from the start end of each sector.

In this operation standby state, the shutter release key
By operating 63 (step S2), one screen of the video signal output from the camera unit 1 is converted into a digital signal by the A / D converter 3 and written into the frame memory (R) 5 (step S2). S3). At this time, the MPU 51 causes the memory control circuit (R) 39 to put the memory (R) 5 into the write enable state for one frame period.

Then, the capstan control circuit 53 causes the tape T to be conveyed in the forward direction at a predetermined speed (step S4), and the memory control circuit (R) 39 performs the write of the tape T in step S3.
The video signal of the frame is expanded in time axis by several hundred times and read out from the memory (R) 5 (step S5). The read signal from the memory (R) 5 is supplied to a band compression circuit 7 and subjected to a well-known digital band compression process such as high-efficiency coding.

On the other hand, at this time, the MPU 51 has the address information indicating the number of the still image currently recorded on the tape from the beginning of the tape, and the track currently being recorded is the track of the recording track of each still image. The sub code generating circuit 33 generates track information or the like indicating this as a sub code. The compressed still image information output from the band compression circuit 7 and the subcode from the subcode generation circuit 33 are time-division multiplexed by the adder 9 for each track. The code sequence time-division multiplexed by the adder 9 is supplied to an ECC (error correction code) encoder 11, and forms a well-known ECC such as a Reed-Solomon code. The output of the ECC encode 11 is digitally modulated at its output end and supplied to the R-side terminal of the switch 13 as a recording signal.

The recording signal via the R side terminal of the switch 13 is
Are recorded on the tape T at the heads Ha and Hb through the head as shown in FIG. In FIG. 2, V1 to V3 are areas in which one frame of compressed still image information is recorded, and a large number (several hundreds) of helical tracks are formed in each of the areas V1 to V3. Further, each of the many tracks has a subcode recording section at an end in the longitudinal direction, and this subcode recording section constitutes subcode areas SB1 to SB3 for one screen. At this time, the address information and the track information are always recorded in the subcode recording section of each track. BL1 to BL3 are blank portions of each sector.

When the reading of the still image information for one frame from the memory (R) 5 is completed (step S6), the reading from the memory (R) 5 is stopped (step S7). In this way,
Recording of one frame of still image information in one of the still image areas V1 to V3 on the tape T is completed, and the subcode area SB1
The recording of the subcode for one of .about.SB3 is completed.

After the recording of one still image is completed, the tape T continues to be transported in the forward direction. That is, in this state, the process returns to step S9, and when it is detected that the heads Ha and Hb are tracing the sector code area, the tape T is stopped (step S1).
0), and return to the operation standby state described above.

Next, the operation of the still image recording / reproducing apparatus of this embodiment during normal reproduction will be described.

When the reproduction key 67 is operated in the operation standby state described above (step S11), the MPU 51 causes the capstan control circuit 53 to operate.
Then, the tape T is transported in the forward direction at a predetermined speed (step S12). At this time, the transport speed is generally the same as that at the time of recording, but the transport speed may be any speed as long as all the still image information of each track can be reproduced stably.

The signal reproduced from the rotating heads Ha and Hb is the switch 15,
It is supplied to the ECC decoder 21 via the P side of the switch 13,
After digital demodulation at the input stage, a code error is corrected. An error flag is supplied from the ECC decoder 21 to the MPU 51 every time an error correction code data block is generated. The code string in which the code error has been corrected by the ECC decoder 21 is supplied to the band extension circuit 23 and the subcode separation circuit 37. The sub-code separation circuit 37 separates the above-mentioned address information, track information, and the like, and supplies them to the MPU 51. On the other hand, the band expansion circuit 23 performs band expansion processing opposite to the band compression processing performed by the band compression circuit 7, and inputs the band-expanded code string to a memory (P) 25 composed of two frame memories. I do.

When the process proceeds from the operation standby state to the step S12, the rotary heads Ha and Hb are on the sector area.
When the transport of the tape T is started, the MPU 51 receives the above-described track information recorded in the subcode area from the subcode separation circuit 37 and monitors this. Then, when it is detected that the track to be reproduced is the first track of each still image area, the head of each still image area is detected (step S13), and the memory control circuit (P) 4
The writing memory is switched from one of the two frame memories 25 to the other according to 1 (step S14), and writing of the still image information to the frame memory which has become the writing memory is also started by the memory control circuit (P) 41 (step S14). S15). That is, in the present embodiment, information stored in the first track of each still image area is stored in one of the two frame memories 25.

When the writing of the still image signal for one frame is completed (step S16), the writing to the frame memory is completed (step S17), and the read memory is switched to the frame memory to which the writing is completed (step S16).
S18). Then, reading of still image information from the frame memory is started. At this time, the still image signal is repeatedly read from the frame memory at the original video rate, converted into an analog video signal by the D / A converter 27, and then output from the output terminal 29 to a monitor device or the like.

In this playback state, the transport of the tape T is continued. If the head of each still image area is detected again in this state (step S13), the writing memory currently being read out in step S14 is read. The same operation is performed by switching from the frame memory to the other frame memory.

In this way, every time one still image area is completely reproduced from the output terminal 29, the next still image signal is output, and the output terminal 29 always outputs the still image signal. Will be.

When the stop key 73 is operated in the normal reproduction state (step S22), the writing and reading of the memory (P) 25 are stopped (step S23), and the reproduction operation ends. Then, returning to step S9, when detecting that the heads Ha and Hb are tracing the sector code area, the tape T is stopped (step S10), and the operation returns to the operation standby state described above.

 Next, the operation in the search mode will be described.

In this embodiment, in the operation standby state, the rotary heads Ha and Hb are always on the above-described sector code area,
When the operation of the numeric keypad 71 is started in this operation standby state (step S41), the MPU 51 causes the sector code separation circuit 35 to operate.
, The number of the sector, that is, the number of the still image recorded in the sector is detected from the above-mentioned sector number information in the sector code, and this is set as the current address information in the variable M (step S42). ). Then, a desired address to be searched specified by the ten keys 71 is set as a target address in the variable N (step S43).

Then, by operating the search key 69 (step
S44) When the apparatus shifts to the search mode, the variable M and the variable N are compared. If M = N (step
S45), and proceed to step S12 to directly proceed to the normal playback mode. As a result, the still image area recorded in the area with the area number N is reproduced first, and the desired still image is reproduced.

If M <N (step S46), the MPU 51 controls the capstan control circuit 53 to rotate the capstan Ca at high speed,
The tape T is conveyed in the forward direction at a speed n times faster than the recording time (step S48). When M <N is not satisfied, it is determined that M> N, and the capstan Ca is similarly rotated at a high speed.
The tape T is transported in the reverse direction at a speed n times faster than when recording (step S47).

In this state, the trace trajectories of the heads Ha and Hb intersect with the longitudinal direction of the track as shown by the arrows in FIG. 2, but the sub-codes must be at least once from each sub-code area corresponding to each still image area. Can be extracted. In this state
The MPU 51 receives the above-mentioned address information included in the sub-code from the sub-code separation circuit 37 (step S49), and updates the current address variable M with this address information. Here, the updated variable M is compared with a number (N-1) one smaller than the target address N (step S51). Here, if M = (N-1), the flow shifts to step S12 to shift to the normal reproduction mode.

Here, the reason why the variable M is compared not with the target address N but with (N-1) will be described. Since the subcode is repeatedly recorded in the entire subcode area corresponding to each still image area as described above, at the time when the variable M is updated, the rotating heads Ha and Hb are
It is not known which track of each sector is being traced. Also, when normal reproduction is performed from the middle of each sector, a complete still image cannot be reproduced. Therefore, in the present embodiment, as described above, the memory starts from the first track of each still image recording area during normal reproduction. Writing to 24 (P) was performed. Therefore, if the normal reproduction mode is entered when the variable M matches the target address N, the still image actually reproduced will be the still image recorded in the area (address) number (N + 1). is there.

As is apparent from the above description, the current address variable M is changed one after another during the high-speed conveyance of the tape T, and when the variable M becomes (N−1), the normal address mode is entered. In step S13, after detecting the first track of each still image area to be reproduced next, information is written to the memory 25 (P), and as a result, the target still image is reproduced.

When the power switch (not shown) is turned off in the operation standby state (step S1), the processing according to the flowchart in FIG. 3 is terminated.

In the apparatus of the embodiment as described above, when searching for a desired still image while transporting the tape T at high speed, the running direction of the tape T is not reversed, and the operator can easily perform the operation without extra operation. A desired screen can be searched.

FIG. 4 is a block diagram showing the configuration of a digital still picture recording / reproducing apparatus as another embodiment of the present invention, and FIG. 5 shows the above format on a tape by the apparatus of FIG. 4 and 5, the same components as those in FIG. 1 or FIG. 2 are denoted by the same reference numerals, and detailed description is omitted.

As is apparent from FIG. 5, the apparatus of this embodiment has a configuration in which a large number of still images are recorded in a continuous area without performing sector division. Therefore, there is no operation of feeding the tape T to the head of each sector after the power switch is turned on or after recording and normal reproduction are completed. That is, there is no operation of the MPU 51 corresponding to steps S8 to S10 in FIG. Therefore, in this embodiment, when the recording is completed, the step
At step S7, the tape T is stopped. At the end of the normal reproduction, the tape T is stopped at step S23.

Further, since the sector code area does not exist, the variable M indicating the current address information is obtained from the address information in the subcode reproduced immediately before the tape T in step S42 in FIG.

Therefore, even at the start of the search, it is not known on which track the rotating heads Ha and Hb are on the tape T in each still image area (indicated by V0 to V4 in FIG. 5). Therefore, in the example of FIG. 1, the step of FIG.
In S45 and S46, the variable M indicating the current address information is compared with the variable N corresponding to the target address. In the present embodiment, however, the variable M is compared with (N-1), and M = ( N
If -1), the process directly shifts to the normal reproduction mode. Otherwise, the tape T is conveyed at a high speed.

With the configuration as described above, a desired screen can be quickly reproduced by a simple operation in the embodiment of FIG. 4 similarly to the embodiment of FIG. In addition, since the recording format is as shown in FIG. 5, the number of still images that can be recorded is larger than that of the apparatus shown in FIG.

[Effects of the Invention] As described above, according to the apparatus of the present invention, a desired still image can be quickly reproduced only by setting the apparatus to the search mode, and the addition of the operator becomes extremely small. This can greatly contribute to the spread of this type of device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a digital still picture recording / reproducing apparatus according to one embodiment of the present invention, FIG. 2 is a view showing a recording format on a tape by the apparatus of FIG. 1, and FIG. Flowchart for explaining the operation of the microprocessing unit (MPU) 51 therein, FIG. 4 is a block diagram showing the configuration of a digital still picture recording / reproducing apparatus according to another embodiment of the present invention, and FIG. 5 is FIG. FIG. 6 is a diagram showing a recording format on a tape by the device of FIG. In the figure, T is a magnetic tape, Ha and Hb are rotating heads, Ca is a capstan, 5 is a frame memory, 7 is a band compression circuit, 11 is an ECC encoder, 13 and 15 are switches, 21 is an ECC decoder, and 23 is Band extension circuit, 25 is two frame memories, 31 is a sector code generation circuit, 33 is a subcode generation circuit, 35 is a sector code separation circuit, 37 is a subcode separation circuit, 39 and 41 are memory control circuits, and 51 is a memory control circuit. Microprocessing unit, 53 is a capstan control circuit, 61 is a timer, 63 is a shutter release key, 65 is a format key, 67 is a playback key that orders normal playback, 69 is a search key that orders high-speed search, 71 is a numeric keypad, and 73 is a numeric keypad. The stop key.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-53-17308 (JP, A) JP-A-57-15268 (JP, A) JP-A-59-201593 (JP, A) JP-A-60-1985 113387 (JP, A) JP-A-2-260258 (JP, A) JP-A-3-269854 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04N 5 / 76-5 / 956

Claims (4)

(57) [Claims] 1. An apparatus for reproducing a still image signal from a tape-shaped recording medium in which still image signals for a plurality of screens are recorded on a plurality of helical tracks per screen, wherein: Address information reproducing means for reproducing address information recorded on a plurality of helical tracks in an area where a still image signal is recorded and indicating the number of each area; and means for inputting desired address information, In a search mode for reproducing the address information from the plurality of helical tracks while transporting the tape-shaped recording medium at a speed higher than a predetermined speed, the address information reproduced by the address information reproducing means is recorded with the desired address information. In response to the coincidence with the number of the area adjacent to the area, the tape-shaped recording medium is conveyed at the predetermined speed, and Serial still image playback device, characterized in that the shift to the normal reproduction mode for reproducing a still image signal. And a memory capable of storing a still image signal for one screen. After the apparatus is set to the normal reproduction mode, a still image reproduced from a first track on which a still image signal of each screen is recorded. 2. The still image reproducing apparatus according to claim 1, wherein writing to said memory is started from an image signal. 3. An apparatus for reproducing a still image signal from a tape-shaped recording medium in which still image signals for a plurality of screens are recorded on a plurality of helical tracks per screen, wherein: Address information reproducing means for reproducing address information indicating the number of each area, each of which is recorded on a plurality of helical tracks in an area where a still image signal is recorded; means for inputting desired address information; The recording medium is transported at a high speed, the address information is reproduced, and an instruction means for instructing a search mode for searching for a still image signal corresponding to the desired address information is provided. If the address information reproduced by the address information reproducing means coincides with the address information immediately before the desired address, the speed corresponding to the time of recording the tape-shaped recording medium is set. A still image reproducing apparatus for transferring to a normal reproduction mode for reproducing the still image signal by conveying the still image signal. 4. A still image signal recorded on the tape-shaped recording medium is encoded with high efficiency, and decoding means is provided for decoding a still image signal reproduced from the tape-shaped recording medium. The still image reproducing apparatus according to claim 3, wherein: