JPS6221184B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an on-vehicle announcement device that selectively reproduces messages recorded on a magnetic drum.

Generally, multiple types of messages are recorded on a magnetic tape such as a cassette tape, and the desired message is selected and played back. However, since each message is recorded serially on the magnetic tape, the selection time is The disadvantage is that it becomes long. Therefore, it has been proposed to use a magnetic drum to record one message per rotation on each track, and to selectively reproduce a desired message by selecting a track. In that case, a playback head can be provided for each track, but since the playback head is expensive, an economical configuration in which the playback head is moved step by step to select tracks as in the 8-track magnetic tape playback apparatus is economical.

The positional relationship between the gap of the magnetic head and a magnetic recording medium such as a magnetic tape must be accurately adjusted in order to stably record and reproduce sound without deteriorating audio quality. Therefore, conventionally, for example, the first
As shown in the figure, a magnetic head adjustment mechanism is used. In the figure, a is a top view, b is a front view, and c is a side view. The magnetic head 1 is fixed to a support plate 2, and the support plate 2 is set at a height from the substrate 4 by screws a to c. is supported so that it can be adjusted. Note that 3 is a spring.

After adjusting the height of the magnetic head 1 using screws a to c, for example, by adjusting screw c as shown in FIG. The inclination to the direction can be adjusted. Further, by adjusting the screw b as shown in FIG. 1c, the parallelism of the surface of the magnetic head 1 with respect to the magnetic recording medium can be adjusted. However, adjusting screws a to c affects height, inclination, and parallelism, so
It is necessary to repeat the adjustment multiple times, and such three-point adjustment requires considerable effort.

SUMMARY OF THE INVENTION An object of the present invention is to facilitate the adjustment of a magnetic head to a magnetic drum and to reproduce a selected desired message with an economical construction. Examples will be described in detail below.

FIG. 2 is a block diagram of an embodiment of the present invention. The magnetic drum 10 has, for example, eight tracks, each track recording one message. The magnetic head is a normal 2-channel head.
The head switching section 12 is configured to move for track selection using a solenoid or the rotational force of the magnetic drum 10. When the message reproduction information MSS is input to the control circuit 22, a start signal is applied to the solenoid drive circuit 16 and the motor drive circuit 21, respectively, head position information is applied to the comparison circuit 18, and head position information is input to the head selection circuit 13. Switching information for selecting the output of the head of one channel and applying it to the reproducing circuit 14 is added. The position of the head switching section 12 is detected by the head position detection section 17 and applied to the comparison circuit 18, and when the head position information matches the detected head position information, a stop signal is applied to the solenoid drive circuit 16.

Further, the motor drive circuit 21 starts the motor 11 in response to a drive signal to rotate the magnetic drum 10. As the magnetic drum 10 rotates, the messages from the two tracks are played back by the two channel head.
A message from one of the tracks is selected by the head selection circuit 13 and amplified by the reproduction circuit 14 to drive the speaker 15.

A detector 19 for detecting the origin of the magnetic drum 10 is provided, and when the origin of the magnetic drum 10 is detected by this detector 19, the origin control circuit 20 applies a stop signal to the motor drive circuit 21, and the control circuit 22 A reset signal is applied to the device to return it to its initial state.

FIG. 3 is a schematic top view of an embodiment of the present invention, and FIG. 4 is a side view, in which a belt 32 is stretched between a pulley 31 of a motor 30 and a flywheel 33.
A shaft 34 of the flywheel 33 is rotatably supported by a bearing portion 35, and the magnetic drum 3 is mounted on this shaft 34.
An idler 37 integrated with the magnetic drum 6 is pressed into contact with the magnetic drum 36, and the shaft of the magnetic drum 36 is supported by a bearing 38.
A bracket 39 supports the tip of the shaft. The magnetic head 40 comes into contact with the magnetic drum 36, and the support plate 41 of the magnetic head 40 is moved by a head switching mechanism 42 to select a track. Further, a cleaning member such as a sponge for cleaning the circumferential surface of the magnetic drum 36 may be provided.

FIG. 5 is a top view of an embodiment of the support portion of the magnetic head, FIG. 6 is a front view, FIG. 7 is a sectional view taken along line A-A in FIG. 5, and FIG. 8 is a B in FIG. - It is a sectional view along the B line. The magnetic head 40 is attached to the holder 44
pins 50, 5 on both sides of the holder 44.
Pins 50, 53 are attached to guide portions 52, 55 of support arms 51, 54 protruding from the support plate 41.
is supported. Also, one end of the support plate 41 is attached with a screw 4.
5 is fixed to the lever portion 43 of the head switching mechanism, and the other end can be adjusted in position with a screw 46. Also, the screw 47 contacts the pin 50,
This is for adjusting the magnetic head 40 in the lateral direction. Note that 48 and 49 are springs.

In FIG. 5, the screw 47 connects the magnetic head 4.
0 can be moved laterally, it is possible to adjust the center of the magnetic drum 36 and the center of the magnetic head 40 to match. In addition, in FIG. 6, the bent portion 41 of the support plate 41 is
The magnetic head 40 supports the magnetic drum 3 with a as a fulcrum.
6 can be adjusted with respect to the running direction. In this case, it is preferable to form a notch 41b in the bent portion 41a.

Furthermore, since the magnetic head 40 can be rotated with the pins 50 and 53 against the circumferential surface of the magnetic drum 36, the circumferential surface of the magnetic drum 36 and the gap surface of the magnetic head 40 can be brought into complete contact by simply pressing into contact. . That is, the parallelism of the magnetic head 40 is automatically obtained. In this case, the support arm 54 can apply pressure to the magnetic drum 36 by a spring action. Note that the support arm 51 may also have the same configuration as the support arm 54.

FIG. 9 is an explanatory diagram of the widths of the magnetic drum 36 and the magnetic head 40. The width W1 of the magnetic drum 36 and the width W2 of the magnetic head 40 have a relationship of W1<W2, and the magnetic head 40 is used for track selection. The width L that is moved for this purpose is in the relationship W1W2-L, and the peripheral surface of the magnetic drum 36 is always aligned with the magnetic head 40.
It is set so that it comes into contact with. this is,
This is because the wear of the magnetic drum 36 is greater than that of the magnetic head 40, so the circumferential surface of the magnetic drum 36 wears out evenly, so that movement of the magnetic head 40 is not hindered.

As explained above, since the present invention uses a magnetic drum, it is more robust than a structure using magnetic tape, and since messages are recorded corresponding to tracks, a desired message can be quickly reproduced. be able to. The width of the magnetic head 40 is larger than the width of the magnetic drum 36, so that even if the magnetic head 40 is moved for track selection, the magnetic head 40 is always on the circumferential surface of the magnetic drum 36.
0 is in contact with the magnetic drum 3.
This prevents uneven wear on the parts 6 and allows stable selective regeneration operation for a long period of time.

The magnetic head 40 also has pins 50 protruding from both sides.
53, the magnetic drum 36
automatically comes into close contact with the circumferential surface of the Further, the inclination of the magnetic head 40 can be adjusted using the adjusting screw 46, and the center of the magnetic head 40 and the center of the magnetic drum 36 can be adjusted to align on a straight line using the adjusting screw 47.
When adjusting 0 in each direction, it can be done without affecting other directions, which has the advantage of facilitating adjustment. It should be noted that the conventional magnetic head adjustment mechanism does not have an adjustment function using the adjustment screw 47, so it has been impossible or difficult to align the magnetic head with respect to the center of the magnetic drum.

[Brief explanation of the drawing]

Figures 1 a to c are top, front and side views of a conventional magnetic head adjustment mechanism, Figure 2 is a block diagram of an embodiment of the present invention, and Figure 3 is a top view of an embodiment of the present invention. , FIG. 4 is a side view, FIG. 5 is a top view of the adjustment mechanism of the magnetic head according to the embodiment of the present invention, FIG. 6 is a front view, and FIG. 7 is a cross section taken along line A-A in FIG. 5. Figure 8 is a sectional view taken along line B-B in Figure 5,
FIG. 9 is an explanatory diagram of the relationship between the magnetic drum and the magnetic head. 10 and 36 are magnetic drums, 11 and 30 are motors, 12 is a head switching section, 13 is a head selection circuit, 14 is a reproduction circuit, 15 is a speaker, 16 is a solenoid drive circuit, 17 is a head position detection section, 1
8 is a comparison circuit, 19 is a detector, 20 is an origin control circuit, 21 is a motor drive circuit, 22 is a control circuit, 3
3 is a flywheel, 34 is a shaft, 37 is an idler, 40 is a magnetic head, 41 is a support plate, 44 is a holder, 46, 47 are adjustment screws, 48, 49 are springs, 50, 53 are pins, 51, 54 are It is a supporting arm.

Claims (1)

[Claims] 1. In an on-vehicle announcement device comprising a magnetic drum on which a plurality of types of messages are recorded corresponding to tracks, and a magnetic head that comes into contact with the magnetic drum and reproduces the recorded messages, the magnetic head comprises:
The magnetic head has a width larger than the width of the magnetic drum and is provided protruding on both sides of the magnetic head so that it is always in contact with the circumferential surface of the magnetic drum even when the magnetic drum is moved to select a track. The magnetic head is rotatably supported by a guide portion formed on a support arm having an elastic force toward the magnetic drum side by a pin provided with the support arm, and the magnetic head is always pressed against the magnetic drum by the elastic force of the support arm. , a support plate integral with the support arm and fixed at one end;
an adjustment screw that adjusts the inclination of the magnetic head; and an adjustment screw that is located on an extension of the pin and pushes one end of the pin to align the center of the magnetic head with the center of the magnetic drum. An in-vehicle announcement device characterized by: