JPH0568019B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording/reproducing device that digitally displays the tracking state of a video head.

Prior Art In conventional magnetic recording and reproducing devices, the drum rotation is controlled so that the drum rotation phase and the phase of the reproduction control pulse have a predetermined relationship during reproduction, and a monostable multivibrator ( The time constant of the camera (hereinafter referred to as ``mono-multi'') can be variably adjusted using a tracking volume, and the tracking status of the video head can be recognized based on the adjustment position of this tracking volume.
Additionally, the tracking status was recognized by envelope-detecting the FM video signal reproduced by the video head and displaying the FM video signal level on a level meter.

Problems to be Solved by the Invention Here, in a magnetic recording/reproducing apparatus using a digital monomulti circuit that varies the delay amount according to supplied time constant data as a monomulti circuit that sets the delay amount of the control pulse. teeth,
For example, since the above time constant data is changed by operating a push button, it is necessary to display the tracking status by displaying the time constant data, and a dedicated signal line is provided to transmit the time constant data to the display for this tracking display. is a waste. In addition, the above device converts the reproduced FM video signal into digital data and processes it digitally. A detection circuit is required to display the level of this FM video signal on the level meter, and the detection output is further transmitted to the level meter. There were problems in that a dedicated signal line was required for the tracking display, and a circuit and parts for tracking display had to be added.

Means for Solving the Problems The present invention provides a magnetic recording system that connects a system controller and a plurality of circuit sections including a display circuit, a servo circuit, and a video circuit through a common bus, and controls the operation of the plurality of circuit sections using the system controller. In the playback device, either the delay amount set in the digital monomulti that delays the playback control pulse signal of the servo circuit or the reference signal whose phase is compared with this, or the maximum level of the playback FM video signal obtained by the video circuit. The above-mentioned problems are solved by supplying the tracking information as tracking information to a display circuit via a common bus to display the tracking status.Each embodiment will be described below with reference to the drawings.

Embodiment FIG. 1 shows a block system diagram of an embodiment to which the device of the present invention is applied. In the figure, 1 is a servo circuit. A drum pulse signal that detects the rotation of the rotating drum is input to a terminal 2 of the servo circuit 1, and a reproduced control pulse signal is input to a terminal 3 of the servo circuit 1. The drum pulse signal is phase-compared with a reference signal having a frequency of approximately 30 Hz from a reference signal generator 5 in a phase comparator 4, and the phase comparator 4 outputs a drum phase error signal, which controls the rotational phase of the drum. be done. Further, the control pulse signal is supplied to the digital monomulti 6. The digital monomulti 6 varies the amount of delay according to time constant data supplied from the register 7, and the control pulse signal delayed here is phase-compared with the reference signal in the phase comparator 8.
The phase comparator 8 outputs a capstan phase error signal, and the rotational phase of the capstan is controlled by this error signal.

The system controller 10 and the servo circuit 1, display circuit 11, video circuit 12, audio circuit 13, and operation key input circuit 14 are connected by a bidirectional common bus 15. The system controller 10 executes the process shown in FIG. 2 after power is turned on. In FIG. 2, initial settings are first performed in step 20 after the power is turned on. After this, in step 21, the operation key input circuit 14
A detection signal indicating the connection state of the operation key detected in is supplied to the system controller 10 via the common bus 15. In step 22, the system controller 10 generates a display drive control signal and supplies it to the display circuit 11 to display the operating mode in order to display the operating mode specified by the connected state of the operation keys. Next, in step 23, detection signals from the reel FG, start sensor, end sensor, unloading switch, afterloading switch, etc. provided in the mechanism section (not shown) are read, and the operating state of the mechanism section is determined. . In step 24, control signals for operating the loading motor and solenoid plunger of the mechanism, and the register 7 of the servo circuit 1, etc. are set in accordance with the operation mode specified by the operation key and the operation state of the mechanism. Constant data etc.
Generates control signals etc. to the servo circuit 1, video circuit 12, and audio circuit 13, respectively, to the mechanical section, servo circuit 1, video circuit 12, and audio circuit 13.
and control their operations.

Thereafter, in step 25, the tracking display process shown in FIG. 3A is performed. In step 26 in FIG. 3A, the register 7 of the servo circuit 1 is
The time constant data stored in is transferred to the system controller 10 via the common bus 15 as tracking information. System controller 1
0 generates a display drive control signal for displaying the time constant data and supplies it to the display circuit 11 in step 27. As a result, the value of the time constant data is digitally displayed in a predetermined format as tracking information on the tracking display of the display circuit 11, and the tracking state of the head is indicated. Steps 21 to 25 above are repeated until the power to the device is cut off.

When the tracking adjustment key among the operation keys is pressed, the system controller 10 sequentially reads time constant data from the built-in memory at predetermined intervals and supplies it to the register 7. As a result, the delay amount of the digital monomulti 6 is sequentially varied, and the value of the time constant data is displayed on the display circuit 11 as tracking information. Adjustments can be made.

In this way, since time constant data is supplied to the display circuit 11 using the common bus 15, there is no need to add a dedicated signal line.

FIG. 4 shows a block system diagram of a second embodiment to which the device of the present invention is applied. In the figure, the same parts as in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted. Fourth
In the figure, FM played by video head 30
The video signal is amplified by the preamplifier 31 and then A/D
is supplied to the converter 32 where the digital
Considered to be an FM signal. This digital FM signal is converted into a well-known luminance FM signal in the video signal processing circuit 33.
Each operation such as signal/carrier color signal separation, FM demodulation, carrier color signal frequency conversion, APC, ACC, de-emphasis, and noise limitation is digitally processed and supplied to a subsequent D/A converter (not shown).
Further, the digital FM signal is supplied to a level detector 34. The level detector 34 has a sampling operation period set by a control signal from the system controller 10, detects the maximum value of the digital FM signal that comes in during this sampling operation period, and transfers the maximum value detection data to the system controller 10. This is used to adjust the head resonance frequency, head Q, recording level of the FM video signal, etc.

In FIG. 4, the system controller 10 also performs the process shown in the second figure, and in step 25 of these processes, executes the process shown in FIG. 3B. In step 28 of FIG. 3B, the level detector 34
The sampled maximum value detection data, that is, the reproduction
The maximum level of the FM video signal is transferred to the system controller 10 via the common bus 15 as tracking information. In the next step 29, the system controller 10 generates a display drive control signal for displaying the maximum value detection data and supplies it to the display circuit 11. As a result, the maximum value detection data is digitally displayed in a predetermined format as tracking information on the tracking display of the display circuit 11, and the tracking state of the head is indicated.

The operator can perform tracking adjustment by reading the tracking display on the display circuit 11 and pressing the tracking adjustment key so that the displayed value is maximized.

In this way, maximum value detection data is obtained by the level detector 34 for adjusting the head resonance frequency, etc., and in order to supply this to the display circuit 11 using the common bus 15, a detection circuit and a dedicated signal line are used. There is no need to add .

Note that in the apparatus shown in the first diagram, the control pulse signal is delayed and compared with the reference signal, but the reference signal may be delayed and compared with the reproduction control pulse signal, and the present invention is not limited to the above embodiment.

Effects As described above, the present invention provides a magnetic recording and reproducing device in which a system controller and a plurality of circuit units including a display circuit, a servo circuit, and a video circuit are connected via a common bus, and the operation of the plurality of circuit units is controlled by the system controller. The amount of delay set in the digital monomulti that delays the reproduction control pulse signal of the servo circuit or the reference signal whose phase is compared with this, and the reproduction obtained by the video circuit.
Since any of the maximum levels of the FM video signal is used as tracking information and is supplied to the display circuit via the common bus to display the tracking status, there is no need to add a dedicated circuit such as a detection circuit to obtain tracking information. Also, there is no need to add a dedicated signal line for supplying this tracking information to the display, which has the advantage of simplifying the circuit configuration and lowering costs.

[Brief explanation of the drawing]

1 and 4 are block system diagrams of each embodiment to which the device of the present invention is applied, FIG. 2 is a flowchart of an embodiment of the processing of the system controller shown in FIGS. 1 and 4, and FIG. 3 A and B are flowcharts of a part of the process shown in the second figure. 1... Servo circuit, 4, 8... Phase comparator, 5... Reference signal generator, 6... Digital mono multi, 7...
Register, 10...System controller, 11...
Display circuit, 12...Video circuit, 13...Audio circuit, 14...Operation key input circuit, 20-
29...Step, 32...A/D converter, 34
...Level detector.

Claims (1)

[Claims] 1 System controller and display circuit,
A magnetic recording and reproducing device that connects a plurality of circuit sections including a servo circuit and a video circuit through a common bus, and controls the operation of the plurality of circuit sections by the system controller, wherein the servo circuit's reproduction control pulse signal or this Tracking information is either the amount of delay set in the digital monomulti that delays the reference signal whose phase is compared with the reference signal, or the maximum level of the reproduced FM video signal obtained by the video circuit, and is supplied to the display circuit via the common bus. 1. A magnetic recording and reproducing device characterized in that a tracking state is displayed by