JP2697831B2 - Playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus for reproducing image information for a plurality of screens recorded on a recording medium. 2. Description of the Related Art Conventionally, a still video system that records or reproduces a still image on a recording medium called video floppy has been known. In such a still video system, a plurality of recording tracks are formed concentrically on a video floppy, and one field of image information can be recorded in one track. A non-recording portion called a guard band is formed between each track to prevent crosstalk between adjacent tracks. For example, according to the standard of the electronic still video system, the track pitch is 100 μm, the track width is 60 μm, and the guard band is 40 μm. On the other hand, when reproducing image information from a recording medium on which a plurality of image information are recorded, each track information can be recognized in a short time, or each track on the recording medium can be quickly forwarded in order to search for specific image information. Often, the need arises. In this case, the head can be moved continuously or intermittently in the direction in which the tracks on the rotating recording medium are arranged, so that the images of the tracks can be sequentially displayed on the monitor screen. [Problems to be Solved by the Invention] However, as described above, when a head is moved between a plurality of tracks on a recording medium, a track in which a signal is recorded and a guard band in which a signal is not recorded are used. In the guard band part, the reproduced image disappears and only the noise is reproduced, and when switching between screens, an extremely high quality underground reproduced image is displayed. Will be done. The present invention prevents a low-quality noise image from being displayed at the time of a search or reproduction in which image information for a plurality of screens recorded on a recording medium is reproduced continuously or intermittently. It is an object to provide a playback device capable of displaying an image. [Means for Solving the Problems] A reproducing apparatus of the present invention has been made for the purpose of solving the above-mentioned problems, and is an apparatus for reproducing image information for a plurality of screens recorded on a recording medium. A reproducing unit for sequentially reproducing image information for a plurality of screens recorded on the recording medium for each screen, and a memory for storing the image information reproduced by the reproducing unit for a plurality of screens. According to the state of the reproduction operation of the image information from the recording medium by the reproducing means, the image information sequentially reproduced from the recording medium for each screen is stored in the memory while the storage in the memory is completed. A memory control unit for sequentially reading out image information for each screen at a predetermined cycle from the image information for a plurality of screens, and an image read from the memory by the memory control unit Display means for displaying information, a low-quality noise image is displayed during search / reproduction for continuously or intermittently reproducing image information for a plurality of screens recorded on a recording medium. That is, the seamless search image can be displayed. [Embodiment] Hereinafter, an embodiment of a reproducing apparatus according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of a reproducing apparatus according to the present invention. In the figure, D is a magnetic disk as a recording medium,
1 is a motor for rotating a disk, 2 is a motor servo circuit for rotating the motor 1 at a constant speed at a predetermined speed, and 3 is a magnetic disk D.
A magnetic head 4 for reproducing the recorded information from above, a pulse motor 4 for moving the magnetic head 3 in the direction in which the recording tracks on the disk D are arranged, and a pulse motor 5 for driving the pulse motor 4 to move the magnetic head 3 to the disk D A motor drive circuit for moving to a predetermined track above; a preamplifier for amplifying information reproduced by the magnetic head 3 to a predetermined level;
Reference numeral 7 denotes a demodulator which demodulates recording information recorded on the magnetic disk D by FM modulation, a reproduction signal processing circuit including a day emphasis circuit and the like, and 8 denotes a digital signal which is a reproduction video signal output from the reproduction signal processing circuit 7. A / D converter, 9 is a first field memory, 10 is a second field memory, 11 is a data selector for selecting from which field memory digital data is read, and 12 is a data selector 11. Is a D / A converter for converting digital signal data read out from the field memory 9 or 10 into an analog video signal via an interface, and 13 is a monitor as a display means for displaying a reproduced image signal.
Reference numeral 14 denotes a control circuit for controlling the operation of each of the above-described circuit blocks, which is constituted by a CPU. Reference numeral 15 denotes an operation unit for instructing each operation mode. In particular, reference numeral 16 denotes a fast-forward playback switch for fast-forwarding a playback image. Next, the operation will be described. First, when a normal reproduction operation is performed, a reproduction operation switch (not shown) arranged in the operation unit 15 is operated, so that a track on the magnetic disk D rotated at a predetermined speed by the motor 1 is moved by the magnetic head 3. The reproduction signal is read and supplied to the reproduction signal processing circuit 7. The reproduction signal processed by the reproduction signal processing circuit 7 is converted into a digital signal by the A / D converter 8 and stored in one of the field memories 9 and 10. Subsequently, the content of one field memory is read out by the data selector 11, converted into an analog signal by the D / A converter 12, supplied to the motor 13, and displayed as image information. Next, a description will be given of a case in which fast-forward playback is continuously performed between recording information tracks recorded on the magnetic disk D one after another. By operating a fast-forward playback switch 16 disposed in the operation unit 15, a fast-forward input terminal IN is provided. As shown in FIG. 2 (a), a signal FF which is at a high level during the operation is input to the control circuit 14. The control circuit 14 outputs a head feed pulse HMP (FIG. 2 (b)) for driving the head motor → pulse motor 4 with a predetermined period of delay from the rise of the signal FF in FIG. It is further supplied to the motor drive circuit 5. In this embodiment, by sending five pulses, the pulse motor 4
The magnetic head 3 is moved by the amount of the track.
Then, the magnetic head sequentially moves to the next track while tracing the guard band between the tracks. During the movement of the magnetic head 3, every time the magnetic head 3 is positioned on each track on the magnetic disk, the envelope EN of the reproduced RF signal from the magnetic head 3 as shown in FIG.
V is output and input to the reproduction signal processing circuit 7. The reproduction signal processing circuit 7 demodulates the input FM-modulated recording information signal and performs processing such as de-emphasis, and then supplies a reproduction video signal to the subsequent A / D converter 8. The video signal is encoded by the A / D converter 8 and converted into a digital signal, and then supplied to the first and second field memories 9 and 10, respectively. On the other hand, the reproduction envelope signal ENV shown in FIG.
Is stable, that is, the drive pulse HM of the pulse motor 4
After a lapse of a predetermined time from the last pulse of P (FIG. 2 (b)), the control circuit 14 sets the first field memory 9
A first field memory 9 stores a digital image information output from the A / D converter 8 by generating a control signal ▲ ▼ (FIG. 2 (d)) for permitting the writing of data.
At this time, the control signal ▲ ▼ (FIG. 2 (e)) for controlling the writing to the second field memory 10 is not enabled, and the writing to the second field memory 10 is prohibited. Absent. Write control signal ▲
▼ and ▲ ▼ each enable writing when the level is Low. After the writing to the field memory 9 is completed, the control circuit 14 generates a drive pulse HMV (FIG. 2 (b)) by driving the head motor pulse motor 4 to move the magnetic head 3 again to move the magnetic head 3 again. . Then, in the same manner as described above, the reproduced RF signal ENV read by the magnetic head 3
Thus, the reproduction signal processing circuit 7 reproduces and outputs the video signal. This reproduced signal is digitally encoded by the A / D converter 8, and then the first and second field memories 9, 10
Supplied to. On the other hand, the write control signal ▲ ▼ to the first field memory 9 is at a high level and writing to the first field memory 9 is prohibited, and nothing is written to the first field memory 9; The previously written content is stored as it is. At this time, the writing to the second field memory 10 is controlled by the control signal ▲ ▼ being Low.
The level is in the enabled state, whereby image information is written into the second field memory 10. This operation is repeated while the fast-forward operation switch 16 is operated and the control signal FF (FIG. 2A) is at a high level. Next, a case where image information stored in the field memories 9 and 10 is read and displayed will be described. The read operation of the field memories 9 and 10 is performed by a read control signal ▲ issued from the control circuit 14 respectively.
▼ (Fig. 2 (f)), ▲ ▼ (Fig. 2 (g))
In either case, the read operation is permitted when the signal is at the low level, and the read operation is prohibited when the signal is at the high level. Before and after the writing to the first field memory 9 described above, as shown in FIG.
▼ is at the Hi level, and reading from the first field memory 9 is prohibited. Further, as shown in FIG. 2 (g), the read control signal ▼ of the second field memory 10 is at the low level, and the read operation is permitted. Next, when writing to the second field memory 10,
Read control signal ▲ output from the control circuit 14
▼ is at the Low level as shown in FIG. 2 (f), and the reading of the information stored in the first field memory 9 is permitted. Further, the read control signal ▼ is at the Hi level as shown in FIG. 2 (g), and reading from the second field memory 10 is prohibited. These field memories 9 and 10 can be read at the same time, but the output data of each is stored in the data secretor 11
Are input to the input terminals A and B. This data selector
11 is a control signal DS supplied by the control circuit 14.
(FIG. 2 (h)) and the control signal DS is low.
The input terminal A is selected when the level is high, and the input terminal B is selected when the level is high. This control signal
When the first field memory 9 writes data, DS goes to the H level so that the input terminal B, that is, the second field memory 10 is selected, and after writing is completed, inversion is repeated as shown in FIG. The inversion pulse is set so that the duty ratio gradually decreases during the 1V (one vertical scan) period, and when the second field memory 10 starts writing, it goes to the low level for the 1V period and becomes the input terminal A, that is, the first terminal.
Of the field memory 9 is selected. After the completion of writing to the second field memory 10, the control signal DS generates a pulse as the duty ratio gradually increases. When the first field memory 9 starts writing, the control signal DS becomes Hi level for 1V. Then, the output of the second field memory 2, that is, the input terminal B is connected to the data selector. In this operation, the data for which the fast-forward switch is selected is D / A
The analog signal is restored by the converter 12 and the monitor 13
Is supplied to and displayed. The switching operation of the data selector 11 will be described in more detail with reference to FIGS. 3 (a) to 3 (f). Assuming that image information is stored in the field memories 9 and 10 one screen at a time, the second 1V indicated by a in FIG.
During the period, both the field memories 9 and 10 can be read, and since the data selector 11 control signal DS is at the Hi level, the input terminal B is switched to display the image information stored in the field memory 10. It is displayed on the device, that is, on the monitor 13 (FIG. 3 (a)). In the next 1 V period b, the control signal DS changes to the low state during the first t _b
Level, t _b after 'period is adapted to the Hi level, thus t _b duration of beginning data selector field memory 9, t _b of the input terminal A, or first' period input terminal B i.e. the The contents of the second field memory 10 are displayed on the monitor screen, as shown in FIG. 3 (b). In the next 1V period c, Deyutei ratio of the pulse is changed, the beginning of t _c period Low level, t _c 'period after becomes Hi level, when compared to the previous 1V period b t _b <a t _c As shown in FIG. 3 (c), the display area of the contents of the first field memory 9 is wider than that of the previous 1V screen, and the contents of the second field memory 10 are correspondingly increased. The display area becomes smaller. By going this way gradually changed so that gradually _{0 <t b <t c <} t d <t e <1V within 1V period pulse Deyutei ratio of the control signal DS by, on the monitor screen From the state where the contents of the second field memory are displayed on the entire screen shown in FIG. 3 (a), the upper part of the screen is displayed as shown in FIGS. 3 (b), (c), (d) and (e). , The image information in the first field memory 9 gradually descends, the contents of the second field memory disappear toward the lower part of the monitor screen, and the first monitor memory occupies the entire monitor screen in the state of FIG. 3 (f). Of the field memory 9 is displayed. Subsequently, at the position f in FIG. 2 (h), reading from the second field memory 10 is prohibited by ▼, and new image information is taken into the second field memory 10. Then, in the next 1 V period g, contrary to the cases of a to e, the pulse of the control signal DS is at the Hi level during the first t _g period, and the pulse at the Low level in the subsequent t _g ′ period. Becomes longer (t _g <t _h <t _i <
t _k ), the area occupied by the image in the second field memory 10 on the monitor screen gradually increases from the upper part of the screen every 1 V, and the image information in the first field memory 9 occupies the monitor screen accordingly. The area disappears down the screen. At the k point, the display screen of the image information in the second field memory 9 is completely displayed.
Readout is prohibited by ▼ and ▲
By ▼, new image information is taken in. As described above, the first field memory 9 and the second field memory 10 are alternately switched, and at the time of the switching, the readout range of the contents of each memory is gradually displaced relatively, whereby the monitor screen is displayed. A so-called scroll operation for gradually switching the screen to the next screen can be performed. Also, by appropriately changing the reading order from the memory and the like, scrolling in both the up and down directions can be performed. As described above, according to the present invention, the signal in the memory is output to the monitor and displayed during the track feeding, and after the track is detected, the recorded information is written into the memory while being reproduced, and the scroll with the previous screen is performed by the memory. Is performed, the screen can be fast-forwarded without displaying the noise reproduction screen when the screen is switched. The above operation is continued while the fast-forward switch 16 is pressed and the control signal FF in FIG. 2A is at the Hi level. In this embodiment, in FIG. 2 (f), the pulse is divided into four stages until the image at the point a in the second field memory 10 is completely switched to the image at the point e in the first field memory 9. Although the duty ratio is switched, finer scrolling can be performed by increasing the number of steps for changing the duty ratio. The scroll speed can also be freely set by increasing or decreasing the number of steps. Further, in the above-described embodiment, the case where the scroll of the record information on the recording medium is performed in the fast-forward, the search, and the like is described. However, the scroll reproduction may be performed in the normal reproduction mode. In addition, by changing the order of the addresses read from the memory, the scroll operation can be performed not only in the up and down directions but also in the left and right directions, which can be realized by changing the memory address control. [Effects of the Invention] As described above, according to the reproducing apparatus of the present invention, when searching and reproducing the image information of a plurality of screens recorded on the recording medium continuously or intermittently, the reproduction apparatus has a high quality. It is possible to provide a reproducing apparatus capable of preventing a low noise image from being displayed and displaying a seamless search image.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a reproducing apparatus according to the present invention, and FIGS. 2 (a) to 2 (h) show writing and reading operations of an image information signal to and from a memory. FIGS. 3 (a) to 3 (f) are diagrams for explaining the display screen on the monitor screen in each operation state based on the operation particularly described in FIG. 2 (f). . Description of reference numeral 1 ... Motor 2 ... Motor servo circuit 3 ... Magnetic head 4 ... Head drive motor 5 ... Motor drive circuit 6 ... Preamplifier 7 ... Reproduction signal processing circuit 8 ... A / D converter 9 ... First field memory 10 Second field memory 11 Data selector 12 D / A converter 13 Display device (monitor) 14 Control circuit 15 Operation unit 16 Fast-forward switch

Claims (1)

(57) [Claims] An apparatus for reproducing image information for a plurality of screens recorded on a recording medium, wherein the reproducing means sequentially reproduces the image information for a plurality of screens recorded on the recording medium for each screen. A memory for storing a plurality of screens of image information to be reproduced by the means, and sequentially reproducing the image information from the recording medium for each screen according to a state of a reproducing operation of the image information from the recording medium in the reproducing means. Memory control means for sequentially reading out image information for each screen at a predetermined cycle from image information for a plurality of screens which have been stored in the memory while storing the image information in the memory; A reproducing unit for displaying image information read from the memory by the memory control unit.