DE1437607A1 - Device for recording and reproducing video signals - Google Patents

Description

R.No. 8ofc PJt »" Ρντ, Ι August 25, 1965

“LI Es / Po

Blaupunkt-Werke GmbH, J> 2 Hildesheim, Robert-Bosch-Straße 200

Device for recording and reproducing video signals (Addition to DBP ....... (patent application

B 78 672 VIIIa / 21al)

The invention relates to a device for recording and reproducing video signals according to DBF ... {patent application B-78- & f ^ rYlTIa. / 2TKTf.

According to claim 5 of the main patent, the method is for recording of video signals of a television program on magnetic tape or the like and for their reproduction, in which the Before recording, video signals are broken down into m contiguous frequency bands and the frequency bands are recorded separately , characterized in that of every m-th television picture only the lowest frequency band, of every (m + l) th TV picture only the next higher frequency band and finally only the highest frequency band of every (2m-l) th TV picture is recorded and each recording is scanned m times.

When scanning, the magnetic tape runs on m one behind the other, Read heads connected in parallel.

There are facilities for recording and reproducing video signals known, which are equipped with a rotating magnetic head carrier around which the magnetic tape is helically guided is.

The device according to the invention for carrying out the method according to the main patent is characterized in that on the circumference of the magnetic head carrier a number η of magnetic heads connected as read and write heads with equal angular distances in a first level, an equal number of magnetic heads connected as pure read heads with equal angular distances in a second level and others as pure read heads

- 1 909804/0388

Blaupunkt-Werke GmbH J R. No. 802 August 25, 1965 32 Hildesheim ^ PLI Es / ΪΌ

switched magnetic heads are arranged one above the other in a total of m levels that the distance between two levels is equal the distance between two tracks recorded on the magnetic tape is that the magnetic heads of one plane are opposite the magnetic heads en the other plane along the circumference at an angle -jj- are offset, which is proportional to the ratio of tape speed in the circumferential direction to the circumferential speed of the magnetic heads and that the angle of wrap of the magnetic tape with respect to of the magnetic head carrier is larger than.

The invention is explained in more detail below on the basis of an exemplary embodiment.

The exemplary embodiment is designed for a method at where the video signals are split into two contiguous frequency bands before recording. With the one below described device should only the lower one, from every second one, when recording the first field of each television picture Field only the upper frequency band can be recorded.

In the drawing there

1 shows the schematic representation of a plan view of the exemplary embodiment,

2 shows the schematic representation of a side view of the Embodiment,

Fig. 3 is a block diagram for recording; and Fig. 4 is a block diagram for reproduction.

The magnetic tape 1 is pulled off a roll 2, guided around a transport cylinder 3 and wound onto a roll 4. The magnetic tape wraps around the transport cylinder 3 in a helical manner in an angular range of more than 360 °. The pitch the coil traversed by the tape is one magnetic tape width.

- 2 9098 04/0388 ORIGINAL INSPECTED

Blaupunkt-Werke GmbH R.Nr. 802 8/25/1965 ■

52 Hildesheim 3 ^PLI Es / ^ ⁰

The transport cylinder 5 consists of two drums 5> 6, which with f. are fastened a small distance above one another on a shaft 7. In the gap between the drums 5, 6 the head carrier 8 rotates, the direction of rotation of which is opposite to the direction of movement of the magnetic tape that covers this gap.

Two magnetic heads 9 and 10 are arranged on the circumference of the head carrier 8. The magnetic heads 9 and 10 lie one above the other in two different planes. The lower of the two magnetic heads 9 is with one magnetic winding 11 and one reading winding 12, the upper magnetic head is equipped with only one reading winding I5. The speed of the head carrier 8 is determined so that just one field is recorded by the magnetic head 9 during one revolution can.

The plane of the magnetic head 10 lies above the plane of the magnetic head by the distance between two tracks recorded by the magnetic head 9 it 9 · along the circumference of the magnetic head 10 is opposite the magnetic head 9 at an angle ^ f, measured in the direction of movement of the magnetic tape, which is proportional to the ratio of tape speed in the direction of the circumference to the peripheral speed the magnetic heads is.

The arrangement and circuitry of the magnetic heads ensures that only one track is written at a time when recording video signals will, however, always read two tracks at the same time when scanning the written tape. Since the picture content two successive television pictures rarely changes by leaps and bounds, the picture impression is also satisfactory if the upper frequency band of the second field of a first television picture is used when scanning the band written with the lower frequency band of the first field of the following TV picture is reassembled into a video signal.

In order to record the video signals 20, these are a frequency crossover 21 and broken down by this into an upper and lower frequency band. Following the crossover network 21 is

909804/0388

ORIGINAL INSPECTED

H37607,

Blaupunkt-Werke GmbH , j R.Nr. 802 August 25, 1965
32 Hildesheim Ί ' "PLI Es / Fo

a write amplifier 22 or 23 | in each of the two channels

intended. The outputs of the write amplifiers are on one ^; - %

Switch 24 out, with which one or the other f

Channel connected to the writing winding 11 of the writing head 9- ' \

can be sen. The toggle switch is activated by -;

the vertical pulses 25 of the video signals 20 are controlled. ϊ

To play back the recording, the currents induced in the Lesewicklun- "gen = 12 and IJ signals in sense amplifiers 26 and 27, I amplified and then fed to an adder 28, in ϊ of the complete video signal of one field wiedergewon- |. Nen is ..I

Instead of one read / write head 9, several |

Read / write heads on the same level with ί that are the same under each other

Provide angular distances and the wrap angle of the magnet £ tape with respect to the magnetic head carrier according to the number of

Share heads. In this case, on the level of pure reading \

head 10 the same number η read heads also with under j?

to be arranged at the same angular distances. The offset angle I

between the read / write head 9 and the pure read head 10 %

is proportional in this case - ~ -. \

If the video signal prior to recording in m together Toggle \

closing frequency bands broken down and only one in one track ?

of the frequency bands recorded, then are available for retrieval;

of the complete video signal a total of m magnetic heads in *.

m planes on top of each other, whereby the offset;.

angle between the lowest and the uppermost magnetic head is equal to * m. ^ is. . ).

Claims (1)

. U.37607 Blaupunkt-Werke GmbH * \ R. No. 802 August 25, 1965 Hildesheim ^u PLI Es / tO Claims , Device for carrying out the method for recording and reproducing video signals according to DBP (patent application B 78 672 VIIIa / 21al) with a rotating magnetic head carrier around which the magnetic tape is helically guided is, characterized in that on the circumference of the magnetic head carrier (8) a number η connected as read and write heads Magnetic heads (9) with the same angular distances in a first plane, the same number as pure reading heads switched magnetic heads (10) with equal angular distances in a second plane and others as pure Read heads switched magnetic heads are arranged one above the other in a total of m levels that the distance between two Planes equal to the distance between two recorded on the magnetic tape Traces is that the magnetic heads of one level opposite the magnetic heads of the other level along the circumference are offset by an angle - ~ - that is proportional to cd 00 the ratio of belt speed in the circumferential direction ^ to the circumferential speed of the magnetic heads and that the angle of wrap of the magnetic tape with respect to the magnetic head - - * ■ 560 ° carrier larger than is. <x> Device according to claim 1, characterized in that on the circumference of the magnetic head carrier (8) a magnetic head (9) equipped with a write winding (11) and a read winding (12) in a first plane and a magnetic head equipped only with a read winding (15) (10) is arranged in a second level above, that the distance between the levels is equal to the distance between two tracks recorded on the magnetic tape, that the upper magnetic head (10) relative to the lower magnetic head (9) along the circumference by an angle ^ ^ in The direction of movement of the tape is offset, which is proportional to the ratio of tape speed in the circumferential direction to the circumferential speed of the magnetic heads and that the angle of wrap of the magnetic tape with respect to the magnetic head carrier (8) is greater than J6O ° + & y .