JPS63155405A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To simplify the circuit assembly structure, and also, to exactly detect a recorded track by setting complementarily power sources of a recording circuit part and a recorded detecting circuit part to a feeding state, respectively. CONSTITUTION:As for a recording circuit part 16 extending from modulating circuit 1, 2 to a recording amplifier, 4 and a circuit part 17 of a recorded detecting circuit 12 and a reproducing circuit 9 from a reproducing amplifier 8, switches 18, 19 are interposed and installed to the respective power source circuit, and both the switches 18, 19 are brought to an ON/OFF control complementarily by a system controller 11. In such a way, the recording circuit part 16, and the circuit part 7 containing the recorded detecting circuit 12 are formed to a shape of one substrate and structure in which they are placed adjacently, and also, to a structure of a usual power source circuit pattern array, and a circuit shield, and an erroneous unrecorded track detection can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording/reproducing device, and more particularly to a still video camera equipped with a recorded detection circuit.

Background of the Invention - Magnetic recording and reproducing devices such as still video cameras are equipped with a recorded detection circuit that detects the presence or absence of recording on each track of a magnetic sheet so that recording can be performed while avoiding recorded tracks when recording image signals. 0 For example, in a still video camera, frame images of a subject are read out from an image sensor through an optical system, these frame images are concentrically recorded on a magnetic sheet as video signals, and the reproduced images can be displayed on a television, etc. However, recording that avoids recorded tracks on the magnetic sheet prevents previously recorded images from being accidentally erased.

Figure 2 shows the configuration of a recording circuit and a recorded detection circuit of a still video camera. A luminance signal Y+S including a synchronizing signal S is FM-modulated by a luminance signal modulation circuit l, and a line-sequential color difference signal R-Y/B-Y is generated. is FM-modulated by the color difference signal modulation circuit 2, and the outputs of both modulation circuits 1 and 2 are mixed by the mixing circuit 3, and supplied as a recording current to the recording/reproducing RAD 6 via the recording amplifier 4 and changeover switch 5. Record on the positioned track of sheet 7 (floppy disk). This recording signal is read out from the head 6 to the reproduction amplifier 8 by switching the changeover switch 5, and is reproduced by the reproduction circuit 9 and taken out as a video signal. The magnetic sheet 7 is the motor 10
The speed control of these motors 1O, the position control of the head 6, etc. are controlled by a system controller 11 made up of a microcomputer.

The recorded detection circuit 12 detects the R signal being reproduced by the reproduction amplifier 8.
The F-fold signal is amplified by the level amplifying circuit 13, then integrated and amplified by the integrating amplifier 14, and compared with a reference voltage by the level comparison circuit 15 to obtain the presence or absence of the RF-multiplied signal, that is, a recording detection signal. When this signal includes a recording presence signal, the system controller 11 moves the head 6 to the next track and waits for detection of recording presence/absence again.

Problems to be Solved by the Invention - In the recorded detection mode in which the recorded detection circuit 11 performs RF multiplied signal detection, the image sensor drive circuit, signal processing circuit, recording circuit, etc. are used in the still video camera in preparation for shooting. Most of the circuits are in an operating state with power turned on. Here, the recorded detection circuit 12 is configured to have a high band and high gain in order to detect the RF multiplied signal. Therefore, the RF multiplied signal included in the signal from the modulation circuit 1.2 to the recording amplifier 4 in the recording circuit arranged on the same substrate may jump into the signal system of the recorded detection circuit by induction or through the power supply. If this jump occurs, the unrecorded magnetic sheet 7
Alternatively, a partially recorded magnetic sheet 7 may be mistakenly detected as recording.

To solve this problem, it is possible to use separate boards for the recording circuit and recorded detection circuit, use separate power supplies, and sufficiently shield both circuits, but these methods increase the size and cost of the device. The problem that leads to this remains.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a magnetic recording/reproducing device that can reliably determine the presence or absence of recording without complicating the device configuration.

- Means and Effects for Solving the Problems The present invention focuses on the fact that image recording and recorded detection are not performed simultaneously, and provides a magnetic recording and reproducing apparatus equipped with a magnetic recording circuit and a recorded detection circuit. Switching means is provided to put the power supply of the magnetic recording circuit and the power supply of the recorded detection circuit into a complementary power supply operation state according to the recording mode and the recorded detection mode, and when one circuit is in operation, the power supply of the other circuit is switched on. Stops the operation and eliminates erroneous input of the RF multiplier signal.

-Embodiment- FIG. 1 is a circuit diagram of a main part showing an embodiment of the present invention. The difference between this figure and FIG. 2 is that the recording circuit section 16 from the modulation circuit 1.2 to the recording amplifier 4, and the circuit section 17 from the reproduction amplifier 8 to the recorded detection circuit 12 and reproduction circuit 9 are connected to their respective power supplies. Switches 18 and 19 are interposed in the circuit,
Both switches 18 and 19 are controlled on and off in a complementary manner by the system controller 11. The switch 18 is turned on in an image recording mode in which the recording circuit portion 16 is in operation, and at this time the switch 19 is turned off.

On the other hand, the switch 19 is turned on in the playback mode or the recorded detection mode in which the playback circuit 17 or the recorded detection circuit 12 is in operation, and at this time the switch 18 is turned off. Note that the changeover switch 5 is omitted.

In such a configuration, switch 1 is used to record the video signal.
8 is turned on, the switch 19 is turned off, and recording is performed with the circuit section 17 in a de-energized state.

On the other hand, when recording an image, the switch 18 is turned off and the switch 19 is turned on to perform recording detection when one circuit section 16 is not supplied with power.

Therefore, for recording completion detection, the operation of the recording circuit section is stopped, and the RF multiplied signal does not enter the recording completion detection circuit 12 side from that section.

Conversely, during the recording operation of the recording circuit, the recorded detection circuit 12
operation stops, and the R from that part to the recording circuit part 16 is
F-fold signal intrusion is eliminated.

From the above, it is clear that the structure in which the recording circuit section 16 and the circuit section 17 including the recorded detection circuit 12 are placed close to each other on one substrate, the normal power supply circuit pattern arrangement, and the structure of the circuit shield prevents erroneous unrecording. Track detection can be prevented. Further, switching and control by the changeover switch 5 are unnecessary, thereby eliminating any influence on the recording signal, and since one of the two circuits is in a non-power-supply state, power consumption is reduced.

In the embodiment, a case has been shown in which the present invention is applied to a still video camera that also has a playback function, but the present invention is not limited to this. It goes without saying that the present invention can be applied to other magnetic recording and reproducing apparatuses to obtain similar effects.

Effects of the Invention As described above, according to the present invention, since the power supplies of the recording circuit portion and the recorded detection circuit portion are complementary to each other, recorded track detection is ensured while simplifying the single circuit assembly structure. This has the effect of reducing power consumption.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a main part showing an embodiment of the present invention, and FIG. 2 is a circuit diagram of a recording circuit and a recorded detection circuit of a conventional magnetic recording/reproducing apparatus. 4... Recording amplifier, 6... Magnetic head, 7... Magnetic sheet, 8... Playback amplifier, 9... Playback circuit. DESCRIPTION OF SYMBOLS 11... System controller, 12... Recorded detection circuit, 13... Level amplifier, 14... Integrating amplifier, 15... Level comparison circuit, 18... Recording circuit part, 17... Circuit part, 18.19... switch.

Claims (1)

[Claims] 1) In a magnetic recording/reproducing device including a magnetic recording circuit and a recorded detection circuit, the power supply for the magnetic recording circuit and the power supply for the recorded detection circuit are supplied in a complementary manner according to a recording mode and a recorded detection mode. A magnetic recording/reproducing device characterized in that it is equipped with a switch means for switching the