DE3036863C2 - Dynamic pickup system - Google Patents

Description

1. In a housing is a rod-shaped needle carrier arranged, the

1.1 with its nominal position by a resiliently pivotable, a _{stylus-supporting] ()} free end out of the housing and is

1.2 by means of a needle carrier bearing preferably made of elastic material is connected to the housing.

2. An induction coil assembly with at least two coil windings is integral with the Connected needle carrier and through this in the yoke of a stationary arranged in the housing Permanent magnets pivotable, the axes of the coil windings essentially are aligned parallel to the needle carrier.

Mark:

3. The induction coil arrangement consists of two in the axial direction of extent (11) of the Needle carrier (2) coaxially one behind the other individual induction coils (5), which as the Needle carrier (2) circumferentially comprehensive cylinder coils are formed.

4. The induction coils (5) are located one behind the other in the area of two in the axial direction Magnet yokes (14, 15) arranged,

4.1 whose field lines (16) both essentially at right angles to one another and to the Extension direction (11) of the needle carrier (2) are arranged at right angles.

2. Pickup system according to claim 1, characterized by the following features:

1. The inner end (10) of the needle carrier (2) is in the axial direction of extent (11) through the Needle carrier bearing (4) through it.

2. The induction coils (5) are on both sides of the needle carrier bearing (4) on the needle carrier (2) arranged.

3. Tonabnehmersyslem according to claim 2, characterized in that the induction coils (5) from Center (12) of the needle carrier bearing (4) have the same axial distance (13).

4. Pickup system according to at least one of the preceding claims, characterized in that that the central axis (17) of the scanning needle (3) with the field lines (16) of both magnet yokes (14, 15) encloses the same acute angle (18).

5. Pickup system according to at least one of the preceding claims, characterized through the following features:

1.2 are bent towards each other in a roof shape in the area of their fixed end (27),

1.3 the free ends (28,30) of each U-leg (23, 25) of each stator lamination (21, 22) are provided with a further turn in such a way that they do not turn off a Free end (29, 31) of a U-leg (24, 26) of the other stator sheet for formation of an air gap at a distance and parallel to each other.

6. Pickup system according to at least one of the preceding claims, characterized through the following features:

1. The needle carrier (2), the needle carrier bearing (4) and the induction coils (5) are in an im substantially tubular needle carrier holder (7) arranged,

1.1 from the needle end (9) of the needle carrier (2) protrudes on one side with its free end (8).

2. The housing has a tubular insertion recess (33) provided,

2.1 in the axial direction of extent (11) between the free ends (28-31) of the U-legs (23-26) and

2.2 whose clear inner diameter is essentially the same as the outer diameter of the Needle carrier holder (2) matches.

7. Pickup system according to claim 6, characterized in that the needle carrier holder (7) is acted upon by the free ends (28-31) of the U-legs (23-26) under radial clamping pressure.

8. Pickup system according to at least one of the preceding claims, characterized through the following features:

The needle carrier holder (7) is at its needle end (9) with a needle insert body (34) provided,

1.1 whose stop surface (36) pointing in the insertion direction (35) has a plurality of connector pins (37),
1.1.1 which, in the final assembly position of the needle carrier holder (7), engage in corresponding plug receiving sockets (38) of a contact surface (39) of the housing (1).

2. The connections (41) of the induction coils (5) are electrically connected to the connector pins (37).

9. Pickup system according to claim 8, characterized in that the plug receiving sockets (38) are electrically connected to external connecting pins (42), which preferably consist of the tonearm facing housing rear wall (43) protrude.

bO The invention relates to a dynamic pickup system with the features of the preamble of claim 1.

Such pickups are known as so-called "moving coil systems" and are based on the Principle of magnetic induction. A pair of coils arranged on a needle carrier is used in the field a strong electromagnet moved so that

by the movement, depending on the momentary change in magnetic flux through the coil cross-section, Voltages are induced in the coil, which - by means of a downstream amplifier - are equalized and amplified - reproduce the information imprinted on a record.

These systems are characterized by particularly low moving masses compared to the otherwise known magnetic pickup systems and ensure a largely faithful to the original, especially transparent rendering. From DE-OS 28 46 179 such a pickup system is known in which attached to a needle carrier in a parallel plane adjacent coils on a plate are, which in turn is connected to the needle carrier via connecting links. For one, there are the output signals such a system is relatively small because of the adjacent coil arrangement only a relatively small number of coil windings can be accommodated. It is therefore necessary in use this pickup system of a further preamplifier connected in front of the equalizer of the amplifier, which also serves as an impedance converter. In addition, they are relatively wide Coil construction and its connecting elements with the needle carrier natural vibrations of the connecting elements and resulting resonances inevitably, reducing the sound of the system is worsened.

The invention is based on the object of improving a dynamic pickup system in such a way that, with good channel separation, it delivers high output signals without disturbing resonance phenomena. This object is achieved by the characterizing features of claim 1. a

Due to the arrangement of the induction coils one behind the other according to the invention on the needle carrier is first a very slim design of the induction coil / needle carrier assembly achieved. As a result, the air gap of the permanent magnet in which the induction coils are located can be selected to be narrower move, creating a strong flux through the coil cross-section and thus relatively high output voltages of approx. 1 mV can be achieved. At such high output voltages, pre-preamplifiers are not τ> more necessary. The spatial separation of the two scanning coils also ensures that they do not influence each other electrically, which results in particularly good crosstalk behavior between the is ensured on both stereo channels. Finally, there is a particularly slim needle carrier coil unit and a good mechanical coupling of the coils to the needle carrier.

The arrangement of the coils on both sides of the needle carrier bearing according to claim 2 is initially 5> an extensive concentration of the coil masses around the needle carrier bearing is achieved. In addition, is the needle carrier is balanced by its storage between the two coil masses like a scale, whereby the impulse behavior of the pickup bo system is improved.

By the characterizing part of claim 3 it is achieved that the induction coils upon movement of the Needle carriers cover the same distance in the air gap of the electromagnet, which makes the difference between the two stereo channels is further reduced when the same signals are sampled.

The characterizing features of claim 4 largely reduce crosstalk between the stereo channels and high flux changes reached when scanning the left or right side writing of the record groove.

The characterizing features of claim 5 is a space-saving, lightweight and inexpensive The arrangement of the permanent magnet to be produced or the one behind one another in the axial direction Magnet yokes made possible.

Due to the arrangement of the needle carrier of the needle carrier bearing and the one attached to the needle carrier Induction coils in a needle carrier holder, which can be pushed into the housing, can be worn or Damage to the main stressed parts of the cartridge carrier with a GriiT can also be replaced by a non-specialist.

The characteristic of claim 7 is initially a vibration-free seat of the needle carrier holder reached in the housing. In addition, the magnet yokes encompass the needle carrier holder as closely as possible radial distance from the associated induction coils, making a particularly powerful Flux is ensured through the coil cross-sections. By arranging a needle insert At the needle end of the needle carrier holder, this can easily be removed from the Housing can be pulled out. The connector pins that are electrically connected to the coils support the tight fit of the needle carrier holder in the housing (claim 8).

Due to the characteristic of claim 9, when changing the needle, the running out of the tonearm Connection cable remain firmly connected to the housing, making the needle change a simple Mating is limited.

The invention is explained in more detail using an exemplary embodiment in five figures of the drawing. It shows

F i g. 1 is a perspective view of the needle carrier holder with the needle insert body, needle carrier and Connector pins,

F i g. 2 is a perspective view of the housing, FIG. 3 shows a section through the needle carrier holder in the direction of extension of the needle carrier,

F i g. 4 is a perspective view of the permanent magnet with essentially U-shaped stator laminations as

F i g. 5 shows a schematic representation of the position of the induction coils and the needle carrier in the magnet yokes.

The pickup consists essentially of a housing 1, a rod-shaped needle carrier 2, to which a scanning needle 3 is attached, a needle carrier bearing 4, induction coils 5 and a permanent magnet 6. The needle carrier bearing 4 is located approximately in the middle of a tubular needle carrier holder 7 and supports the needle carrier 2 in such a way that it is essentially coaxially and centrally in the rest position the needle carrier holder 7 is located. The free end 8 of the needle carrier 2 protrudes from the needle end 9 of the needle carrier holder 7 out. The inner end 10 of the needle carrier 2 opposite the free end 8 is standing dui ^ h the needle carrier bearing 4 through.

The induction coils lie one behind the other in the axial direction of extent 11 of the needle carrier 2 and are designed as cylinder coils which are pushed onto the needle carrier 2, the coil axes being coaxial

run with the needle carrier 2.

Both induction coils 5 have the same axial distance 13 from the center 12 of the needle carrier bearing 4.

A magnet yoke 14, 15 is provided for each of the induction coils 5, the magnet yokes in Extension direction 11 lie one behind the other and from each other have the same axial distance as the coils 5. The field lines 16 of the magnet yokes 14, 15 are formed substantially at right angles to one another. Also to the axial direction of extent 11 of the needle carrier 2 they are arranged at right angles.

Relative to the scanning needle 3, the magnetic yokes 14, 15 occupy such a spatial position that the central axis 17 of the scanning needle 3 with the field lines 16 of both magnet yokes 14, 15 have the same acute angle 18 includes.

At the pole ends 19, 20 of the permanent magnet 6, U-shaped stator plates 21, 22 are arranged, the U-legs 23, 24, 25, 26 of which extend at right angles to the axial direction II of the needle carrier 2 and protrude into the area of the needle carrier 2. In the area of their fixed end 27, all U-legs 23-26 are bent in such a way that they can be placed on top of one another in the shape of a roof. The free ends 28, 30 of the U-legs 23, 25 are bent again in such a way that they lie opposite the non-bent free ends 29, 31 at a distance and parallel to form an air gap 32.

To accommodate the needle carrier holder 7, the housing I is provided with an insertion recess 33 which runs in the axial direction of extension 11 between the ends 28-31 of the U-legs 23-26 and whose clear inner diameter essentially corresponds to the outer diameter of the needle carrier holder 2.

The needle carrier holder 7 is provided at its needle end 9 with a needle insertion body 34, from whose stop hook 36 pointing in the insertion direction 35 a plurality of connector pins 37 protrude in the insertion direction 35. When the needle carrier holder 7 is pushed into the housing 1, the connector pins 37 are located in connector receiving sockets 38 which are formed in a contact surface 39 of the housing 1 that is parallel to the stop surface 36. The connections of the induction coils 5 are electrically connected to the connector pins 37 via fine wires 40. To produce an electrical contact between the connecting wires of the tonearm and the induction coils 5, the connector receptacles 38 are connected by means of external connecting wires 41 to external connecting pins 42 which protrude from a rear wall 43 of the housing.

For this purpose 2 sheets of drawings

Claims (1)

Claims:. At the pole ends (19, 20) of the permanent magnet (6), essentially U-shaped stator sheets (21, 22) are arranged, 1.1 of which the U-legs (23- 26) stand as pole shoes of the magnet yokes (14, 15) next to the induction coils (5) in the area of extent of the needle strap (2), 20 1. Dynamic pickup system for scanning stereo or quadrophone records, with the characteristics: