JPH0633575Y2 - Disk player - Google Patents

Description

TECHNICAL FIELD The present invention particularly relates to a disk provided with a main power supply line for supplying a main power supply voltage from a main power supply and a backup power supply line for supplying a backup power supply voltage from a backup power supply. Regarding the player.

BACKGROUND ART Conventionally, in this type of disc player, it is general to provide a power supply line for each power supply. However, considering the simplification of the wiring structure and the ease of the wiring work, even one wiring is required. It is desirable to be able to reduce.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to provide a disc player capable of reducing wiring.

The disc player according to the present invention is characterized in that the backup power supply voltage supply line is also used as a communication line for transmitting information between two independent microcomputers.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

1 and 2 are block diagrams showing the configuration of a control system of a vehicle-mounted disc player as an embodiment of the present invention. This control system includes a host microcomputer 200 that controls the entire system, at least an operation unit 201, and a display unit.
A sub-microcomputer 203 that controls 202, and these microcomputers 200, 203 are mounted in units separated from each other, a main power supply line 204 for supplying a main power supply voltage, a constant voltage power supply line 205, and a backup power supply. Supplying voltage and host microcomputer 20
0 and the sub-microcomputer 203 are connected via a backup power supply line 206 used for communication of information. The main power supply voltage is supplied to the host microcomputer side via the sub-microcomputer side, but it goes without saying that it may be directly supplied to the host microcomputer side.

The switch 207 provided on the main power supply line 204 is a so-called accessory switch of an automobile, and the switch 20
When 7 is turned on (closed), the power supply voltage V _DD stabilized by the stabilizing circuit 208 instantly rises as shown in FIG. 3 (a). The output of the reset circuit 209 gradually rises with respect to the power supply voltage V _DD (a) with a predetermined time constant as shown in FIG. 3 (b), and when the predetermined level V ₁ is reached, the host microcomputer 200 is reset. The host microcomputer 200 issues a control signal after a lapse of a certain time T from the reset time, and operates the power switch 210 inserted in the constant voltage power line 205 between the two microcomputers so as to supply the power voltage V _DD to the sub microcomputer 203. Turn it on. This allows the sub-microcomputer 20
3, and the power supply voltage V _DD supplied to the reset circuit 211 rises as shown in FIG. 3 (c). The output of the reset circuit 211 gradually rises with respect to the power supply voltage (c) with a predetermined time constant as shown in FIG. 3 (d), and when the predetermined level V ₂ is reached, the sub-microcomputer 203 is reset.

In this way, by controlling the supply of the power supply voltage of the sub-microcomputer 203 by the host microcomputer 200, both microcomputers 20
The synchronization of 0 and 203 can be maintained. Here, considering the case where such a synchronization method is not adopted, it is necessary to provide a dedicated synchronization line for synchronizing both the microcomputers 200 and 203, and the wiring structure becomes complicated and the work time also increases accordingly. It will be. Further, in the case where the rise of the power supply voltage is separately synchronized, both the reset circuits 209 and 211 need to have a complicated circuit configuration as shown in FIG. However, by controlling the supply of the power supply voltage of the sub-microcomputer 203 by the host microcomputer 200, the reset circuit 211 on the sub-microcomputer 203 side can be a simple circuit having the configuration shown in FIG. As a result, the circuit configuration can be simplified.

The reset circuit 209 on the host microcomputer 200 side can detect that the main power supply voltage due to the main power supply line has momentarily cut off. At this time, as is apparent from FIG. 3 (a), even if there is a momentary interruption of the main power supply voltage, the host microcomputer 200 and the sub-microcomputer 203 are reset at a fixed timing, and the synchronization between them can be maintained. You can do it.

As shown in FIG. 2, the host microcomputer 200 has an address memory 212 and a backup memory 213.
When the switch 207 is off and the main power supply voltage is cut off by the main power supply line 204, the backup power supply voltage supplied by the backup power supply line 206 to the backup memory 213 is submicro. It is supplied from the computer 203 side.

That is, in FIG. 1 and FIG. 2, the backup power supply voltage is made constant by the resistor R ₁ and the Zener diode ZD, and the backup power supply line 2 between the sub-microcomputer 203 and the host microcomputer 200.
The power is supplied to the power supply terminal of the host microcomputer 200 via 06 and the diode D1.

Further, the collector of a transistor Q having a grounded emitter is connected to the anode side of the diode D1, that is, the backup power supply line 206.

With this configuration, the switch 2 on the main power line 204
When 07 is turned off, the power failure detection circuit 221 detects that the supply of the main power supply voltage from the main power supply line 204 is cut off. Then, the host microcomputer 200 turns off the transistor Q based on the nuclear detection output and receives the backup power supply voltage from the backup power supply line 206 via the diode D1. As a result, the host microcomputer 200 turns off the switch 207 and cuts off the supply of the main power supply voltage from the main power supply line 204.
The backup memory 213 provided in the host microcomputer 200 can hold the stored information.

When the switch 207 is on and the main power supply voltage from the main power supply line 204 is supplied to the host microcomputer 200, the backup power supply line 20
6 can communicate information by the following methods.

That is, the host microcomputer 200 supplies the command signal to the base of the transistor Q via the resistor R ₃ and the potential of the backup power supply line 206 because the diode D 1 is non-conductive under the supply of the main power. Can be changed. This potential change is relayed to the communication terminal of the sub-microcomputer 203 through R ₄ as a relay means as a command signal from the host microcomputer 200.

In FIG. 1, the play start switch SW ₂ for instructing the start of play is a normally closed type switch, and is connected in series with the detection switch SW ₂ for detecting that the disc has been transported to the eject position. The disc D, which is inserted from a slot (not shown) formed on the front surface of the player main body and positioned at a predetermined position, is activated when the disc D is slightly pushed in the disc insertion direction to be in the open state. One end of these switch series connection circuits is connected to the input end of the sub-microcomputer 203, the power supply voltage V _DD is supplied through the resistor R ₂ , and the other end is grounded. When the disc is transported to the eject position after the performance, the detection switch SW ₂ closes, so a low-level detection signal is sent to the sub-microcomputer.
It is supplied to the input terminal of 203. On the other hand, when the disc is slightly pushed in the inserting direction at the eject position, the play start switch SW ₁ is opened, the input end of the sub-microcomputer 203, which was at a low level, shifts to a high level and a replay command is issued. Is detected.

The loading mechanism 214 that conveys the disc inserted from the slot on the front of the player body to the playing position and the pickup moving mechanism 216 that moves the pickup 215 in the radial direction of the disc include the host microcomputer 2
The main power supply voltage is supplied via a main power supply switch 217 which is on / off controlled by 00. The host microcomputer 200 uses the loading mechanism 214 and the pickup moving mechanism 216 when the player system is used in combination with another source, for example, a tape deck or a tuner, when another source is input during performance. The main power switch 217 is turned off to stop the supply of main power to the main power supply.

In FIG. 2, program information including address information is recorded on the disc D, and this recorded information is read by the pickup 215. The information read by the pickup 215 passes through the demodulation circuit 218 and the address determination circuit 2
Address information is detected at 19 and pickup 215
The current position of is determined. The latest address information is the address memory 212 in the host microcomputer 200.
Stored in. Reference numeral 220 is a focus detection circuit that constantly monitors whether or not the pickup 215 is in focus based on the output of the pickup 215, and outputs an output when the focus is out of focus. When the output of the focus detection circuit 220 is generated, the host microcomputer 200 drives and controls the pickup moving mechanism 216 so as to return the pickup 215 to the home position, and also controls the focus at the home position again. Then, after the focus is taken again, the pickup 215 is moved to the immediately preceding address so that the performance is restarted from the address immediately before being out of focus stored in the address memory 212.

During the performance, when the accessory switch of the automobile, that is, the switch 207 is turned off and the main power supply of the system (main power supply voltage to the host microcomputer 200 by the main power supply line) is cut off, the power failure detection circuit 211 Detects this and produces an output. Due to the generation of this detection output, the latest address information stored in the address memory 212 in the host microcomputer 200 is written in the backup memory 213. When the main power is supplied again, the performance is started from the address written in the backup memory 213.

Further, in the host microcomputer 200, a counter 222 for sequentially counting expected address information to be moved next by the pickup 215 by performing a counting operation in a constant cycle during performance, a latest address information from the address memory 212 and a counter 222. The detection circuit 223, which generates an output when there is a discrepancy between the expected address information and the expected address information, is built in, and the host microcomputer 200 follows the recording track of the disk D with the output of the detection circuit 223. It is determined that the information reading point of the pickup 215 jumped over the track. When it is determined that the track has skipped, the pickup moving mechanism 216 is drive-controlled to move the information reading point of the pickup 215 to the expected address by the output of the counter 222.

If the information recorded on the disc D is a musical sound,
Even if the information between the final read address and the expected address is not read by moving the pickup 215 to the expected address as described above, there is no effect on the audibility, but when the recorded information is the control information, it is always necessary. Since it is necessary to read, in such a case, all the information can be read accurately by moving the pickup 215 to the final read address.

Effect of the Invention As described above, in the disk player according to the present invention, the backup power supply voltage supply line is also used as a communication line for transmitting information between the two microcomputers, so wiring is reduced. Therefore, the wiring structure can be simplified and the wiring work can be facilitated.

[Brief description of drawings]

1 and 2 are block diagrams showing the configuration of a control system of an in-vehicle disc player according to the present invention, FIG. 3 is a waveform diagram of respective portions (a) to (d) in FIG. 1, FIG. Fifth
The figure is a circuit diagram of the reset circuits 209 and 211 in FIG. Explanation of symbols of main parts 200 …… Host microcomputer 203 …… Sub-microcomputer 209, 211 …… Reset circuit 212 …… Address memory 213 …… Backup memory 214 …… Loading mechanism 215 …… Pickup 220 …… Focus detection circuit 221 ...... Power failure detection circuit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hiroyuki Hirano 4-2610 Hanazono, Tokorozawa, Saitama Prefecture Pioneer Co., Ltd. Tokorozawa Plant (72) Yoichi Ogawa 4-2610 Hanazono, Tokorozawa, Saitama Prefecture Pioneer Co., Ltd. Tokorozawa Factory Examiner Yoshinori Shingu

Claims (1)

[Scope of utility model registration request] 1. A host microcomputer, a sub-microcomputer that operates in response to a command from the host microcomputer, a main power supply voltage supply means for supplying a main power supply voltage to a power supply terminal of the host microcomputer, and the power supply. In a disc player including a backup power supply means for supplying a backup power supply voltage to a terminal, the backup power supply means supplies the backup power supply voltage for generating the backup power supply voltage via a unidirectional element (D1). A backup power supply line (206) for relaying to the power supply terminal, a control element (Q) for changing the potential of the backup power supply line under the control of a command from the host microcomputer, and a potential change of the backup power supply line. The service Disc player, wherein the relay means for relaying as the command to the microcomputer (R4), in that it consists of.