JPS63261962A - Wipe circuit for picture file system - Google Patents

Abstract

PURPOSE:To dissolve the unsightly display of a picture or the change of a luminance by erasing a former picture by wiping a monitor picture simultaneously with the start of a search at the time of the update of a reproduced picture, and displaying the updated picture afterward at the time that a search address is regenerated. CONSTITUTION:A search pulse generation circuit 5 outputs a search pulse (c), synchronizing with the rise up of a search flag signal (a) from an optical disk player 1, and on receiving it, an updown counter 9 turns into an up-mode. On the other hand, a horizontal synchronizing signal from a band compression decoder 2 is inputted to the counter 9 through a 1/21 frequency division circuit 6 and a variable frequency division circuit 7, and counted up. The counted output passes through a D/A converter 10, and is integrated 11, and the integrated output is inputted to a comparator 12, and level-compared with a saw tooth wave outputted from a saw tooth wave generation circuit 8 by the horizontal synchronizing signal. On receiving the outputted blanking pulse (h), a blanking control circuit 3 erases a high definition video signal from the decoder 2 from the left to the right of the monitor picture frame accompanying the up count of the counter 9. Afterward, it displays the video signal according to the negative flag signal (b) from the right to the left.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a wipe circuit that makes the monitor of an image file system easier to view.

(b) Conventional technology Regarding the configuration for reproducing high-quality still image video signals, for example, Japanese Patent Laid-Open No. 118084/1984 (HO4N7
/13). This prior art discloses a band compression decoder that stores four fields of a band compression video signal to be reproduced in a memory and forms a high-quality still image while cyclically deriving the stored information.

The above-mentioned band compression decoder is incorporated into an image file system, and this image file system searches for a specified address and makes it possible to reproduce desired still image information.

l/1 Problems to be Solved by the Invention However, the conventional image file system described above circulates stored information to form a still image until new still image information is reproduced. Since the memory is updated immediately after playback and a new still image is formed, it is difficult to visually see the large brightness changes caused by switching images.

B) Means for Solving the Problems The present invention has been made in view of the above-mentioned points, and provides a counter that starts counting when a search command signal is generated and starts subtractive counting when a still command is generated, and a counter that starts counting when a search command signal is generated, and a counter that starts counting by subtracting when a still command is generated. a DA conversion circuit that converts the signal into DA, a sawtooth wave generation circuit that forms a sawtooth wave synchronized with a horizontal synchronization signal, and a blanking pulse is generated by comparing the output of the DA conversion circuit and the output of the sawtooth wave generation circuit. and a blanking control circuit which uses the blanking pulse as a control input and the decoder output as a signal input, respectively.

(e) According to the present invention, when updating the playback screen, the monitor screen is wiped from left to right at the start of the search to erase the original screen, and then when the search address is played back, the monitor screen is wiped from right to left. It will be wiped and an update screen will be displayed.

(f) Example Hereinafter, the present invention will be explained according to an illustrative embodiment.

In this embodiment, the output of the conventional band compression decoder described above is input to a blanking control circuit to perform a wipe operation, and as shown in FIG. When reproducing a specified address, an optical disc player (1) that reproduces a search flag signal () is derived from the start of a search. The generation period of this search flag signal is set to 1 second or more, and if the search for an address that precedes the search address by a predetermined field is completed within 1 second, the system enters a standby state at that preceding address and waits for at least 1 second. It is deactivated when the search elapses, but if it takes more than 1 second to complete the search, it is deactivated at the same time as the search is completed.

When the search brag signal is deactivated, the disc player (1
) falls into the synchronous pull-in state, and the synchronous pull-in flag signal (b)
Derive. This synchronization pull-in flag signal width) is generated during the period from the preceding address until the specified address is reproduced. During the generation period of this synchronization pull-in flag signal To), the band compression decoder (2) interrupts the free oscillation state of the master clock generation circuit and externally synchronizes the master clock with the playback output input from the video disc player (1). It's forcing me.

Therefore, the playback output corresponding to the specified address is written into the memory in synchronization with the master clock that is in a synchronous relationship with the playback output, and at the end of writing, the synchronization pull-in flag signal (bl is deactivated, and subsequent is performed in synchronization with the free-running master clock.

The operation of the wipe circuit of this embodiment will be explained below. First, a search pulse generation circuit (51) to which the search flag signal (a) is input generates a search pulse [C] in synchronization with the rise of the search flag signal. In response to this search pulse, the 8-bit up/down counter (9) enters the up mode. On the other hand, the external frequency divider circuit (6), which inputs the 33.7KHz horizontal and horizontal synchronous signals obtained from the band compression decoder, outputs a 1.6KHz division output, and the variable divider circuit (6) inputs this frequency division output. The frequency circuit (7) uses the divided output of 100 to s OOHz according to the setting as the counting input of the up/down counter (9). Therefore, this up/down counter (9) counts up in the range of 0.3 to 2.5 seconds.

However, in this embodiment, since the minimum Hals width of the search flag signal fal is set to 1 second, the count-up period must be set to 1 second or more, and the variable frequency divider circuit (
The branch output of 7) must be set in the range of 100 to 400 Hz. Furthermore, this up/down counter (9)
has a hold function and does not count up to 256 or more or count down to less than 0, but performs counting within the limit count value.

The count output of this up/down counter (9) is input to the DA conversion circuit aα and converted into an analog signal, and then input to the integration circuit (Integrator). Therefore, the integral output [e) is the second
Changes as shown in the figure.

Also, a sawtooth wave generation circuit (9) that inputs a horizontal synchronization signal
(see FIG. 3) is derived, and the level is compared with the integral output in the comparator @. As a result, a planking pulse opening as shown in FIG. 3 is derived. This blanking pulse is used as a control input,
The blanking control circuit (3) receives the high-quality still image video signal output from the band compression decoder (2) as a signal input.
A high-quality video signal is derived only at the timing of the blanking output power level, and as the up-down counter (9) counts up, the monitor screen is erased from left to right (Fig. 4 A-C reference).

After the monitor screen completely disappears, the search flag signal fa
) is erased, a negative synchronization pull-in flag signal 1b) is generated, the video disc player (1) starts playing from the preceding address, and the band compression decoder (2) enters the synchronization pull-in state. When the video disc player (1) plays a specified address, the band compression decoder (2)
has completed synchronization pull-in, the playback output corresponding to the designated address is input to the band compression decoder (2), the memory is updated, and an updated high-quality video signal is derived. Synchronous pull flag signal (
The still pulse generating circuit (41c) inputs bl to the still pulse (mountain up/down counter (9)) and sets the up/down counter (9) to the down mode.

Thereafter, the up/down counter (9) counts down the variable frequency division output. As a result of down-counting, the level of the DA conversion output (e) is lowered, the pulse width of the blanking pulse is reduced, and the updated high-definition video signal is displayed in the form of a wipe from right to left. Figure 4 C~
(see E).

(g) Effects of the Invention According to the present invention, the screen is wiped every time the screen is updated, and it is possible to solve the problem of displaying an unsightly screen and the difficulty of seeing due to changes in brightness, which is very effective.

[Brief explanation of drawings]

Each figure shows an embodiment of the present invention, and FIG. 1 is a block diagram of the main circuit, FIG. 2 is a signal waveform diagram of the main part, FIG. 3 is a signal waveform diagram of the main part with the time axis enlarged, and The figures each show an explanatory diagram of monitor screen changes. (9)... Up/down counter, αQ... DA conversion circuit, (8)... Sawtooth wave generation circuit, ■... Converter, (3)... Blanking control circuit.

Claims (1)

[Claims] (1) In order to play back a video disc record in which still image information forms a continuous recording track together with an address signal, a search is started in synchronization with a search command signal, and a search is started in synchronization with a still signal issued in conjunction with search address playback. In an image file system that updates the stored contents of the image memory and switches the monitor screen to still image information corresponding to the search address, the search command signal is input, a low frequency clock is counted, and the still signal is input. a counter that inversely counts the low frequency clock; a DA conversion circuit that converts the output of the counter from digital to analog; a sawtooth wave generation circuit that forms a sawtooth wave signal synchronized with the horizontal deflection of the monitor screen; a comparator that compares the levels of the output of the DA conversion circuit and the sawtooth wave signal to convert the sawtooth wave signal into a rectangular wave signal; and a blanking control circuit for blocking passage of the image memory output during a signal generation period.