JPH023610Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a rotary transformer for transmitting signals between a rotating magnetic head and a signal circuit in a video tape recorder or the like.

[Prior art]

Generally, in magnetic recording and reproducing equipment such as video tape recorders, multi-channel rotary transformers are used to transmit signals between a plurality of rotating magnetic heads and signal circuits. Conventionally, the following devices have been used as this type of device.

FIG. 1 is a sectional view of a conventional flat plate two-channel rotary transformer provided with a short ring. In the figure, 1 is a rotating core and 2 is a fixed core, which are paired with each other. Reference numeral 3a denotes a first channel rotating side coil provided in the rotating core 1, and is connected to the first channel of the plurality of magnetic heads. Similarly, reference numeral 3b denotes a rotating side coil of the second channel, which is connected to the second channel among the plurality of rotating magnetic heads. 4a is a fixed side coil of the first channel provided in the fixed core 2;
It is magnetically coupled with the rotating side coil 3a of the channel to form a magnetic path indicated by 10a in the figure.
Similarly, 4b is a fixed side coil of the second channel, which is magnetically coupled with the rotating side coil 3b of the second channel to form a magnetic path indicated by 10b in the figure. 5 is a rotating side shot ring provided between the rotating side coils 3a and 3b, and 6 is a stationary side coil 4.
This is a fixed side shot ring provided between a and 4b. 7 is a gap between the rotating core 1 and the fixed core 2, 8 is a rotating core support stand, and 9 is a fixed core support stand.

A conventional rotary transformer is constructed as described above. For example, as shown in FIG.
A magnetic path of 0a and 10b is formed, and the fixed side coil 4
A voltage is induced in a and 4b, and a signal is transmitted.

This is the rotating coil 3a of the first channel.
The magnetic flux generated by the current flowing in also forms a magnetic path 11 surrounding the rotating coils 3a, 3b and fixed coils 4a, 4b, and also induces voltage in the fixed coil 4b of the second channel, causing a cross Talk occurs.

However, when the leakage magnetic flux from the first channel to the second channel surrounds the shot rings 5 and 6, a back electromotive force is generated in the shot rings 5 and 6, and a magnetic flux in the opposite direction that cancels the leakage magnetic flux is generated, causing the leakage magnetic flux to Decrease. The leakage magnetic flux from the second channel to the first channel is also reduced by the shot rings 5, 6. The shot rings 5 and 6 thus have the effect of reducing crosstalk.

However, since the short ring is provided between each channel as described above, the effective opposing area of the gap of each channel becomes small, and the transmission efficiency between the stationary side coil and rotating side coil of the same channel decreases. In particular, as rotary transformers become smaller and have more channels, the deterioration of transmission characteristics due to the presence of short rings becomes a drawback that cannot be ignored.

[Summary of the idea]

This invention was made for the purpose of improving this drawback, and by providing a plurality of independently electrically openable and closable shot rings between the coils of each channel, it only reduces crosstalk between channels. Instead, it provides a rotary transformer that can improve transmission characteristics between the same channels.

[Example of idea]

FIG. 2 is a sectional view of a two-channel flat plate rotary transformer showing an embodiment of this invention.
1, 2, 3a, 3b, 4a, 4b, and 7 to 9 are completely the same as those of the conventional device.

5a is a rotating side shot ring of the first channel that can be electrically opened and closed; 5b is a rotating side shot ring of the second channel that can be electrically opened and closed; 6a is a rotating side shot ring of the first channel that can be electrically opened and closed; 6b is an electrically This is a fixed side shot ring of the second channel that can be opened and closed.

In a multi-channel rotary transformer configured as described above, for example, as shown in Figure 2, the signal is weak as in the case where the first channel is in playback operation, and it is necessary to improve the transmission characteristics. In the second channel, when the signal is relatively strong and there is no need to particularly increase the transmission efficiency, such as during recording operation, the short ring 5a of the first channel,
5b is electrically opened. By doing this, the shot rings 5a, 5b of the first channel
loses its effect of blocking magnetic flux, the effective opposing area of the gap portion increases, and the transmission characteristics of the first channel improve.

On the other hand, the shot rings 5b and 6 of the second channel
If b is short-circuited, crosstalk from the second channel to the first channel can also be reduced.

By the way, in the above explanation, the present invention was described in the case of a two-channel flat plate rotary transformer, but even in the case of a multi-channel rotary transformer having two or more channels, a plurality of independent electric currents are connected between each coil. Providing a shot ring that can be opened and closed is effective in improving transmission characteristics and reducing crosstalk.
It goes without saying that it can also be used for a cylindrical rotary transformer.

[Effect of idea]

As explained above, this idea improves transmission characteristics and reduces crosstalk at the same time by providing multiple independently electrically openable and closable shot rings between the coils of each channel of the rotary transformer. This has the effect of making it smaller.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional flat plate type two-channel rotary transformer, and FIG. 2 is a cross-sectional view of a flat plate type two-channel rotary transformer showing an embodiment of this invention. In the figure, 1 is a rotating core, 2 is a fixed core, and 3 is a rotating core.
a, 3b are rotating side coils, 4a, 4b are stationary side coils, 5a, 5b are rotating side shot rings, 6
A and 6b are stationary shot rings, 7 is a gap, and 10a and 10b are magnetic paths. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] The rotary core is provided with a rotating core and a fixed core that are paired with each other and face each other through a gap. A plurality of fixed side coils are provided which are magnetically coupled with the rotating side coils to form a plurality of magnetic paths, and a leakage magnetic field is provided between the plurality of fixed side coils and between the plurality of rotating side coils. What is claimed is: 1. A rotary transformer provided with a conductive shield member for interrupting the flow, wherein the shield member has a plurality of shot rings, and each shot ring is configured to be able to be electrically opened and closed independently.