WO1995024060A1

WO1995024060A1 - Small radio watch

Info

Publication number: WO1995024060A1
Application number: PCT/DE1995/000269
Authority: WO
Inventors: Walter Buck
Original assignee: Erich Lacher Uhrenfabrik Gmbh & Co. Kg
Priority date: 1994-03-04
Filing date: 1995-02-25
Publication date: 1995-09-08
Also published as: EP0697140A1; DE4407116A1

Abstract

A long-wave aerial for insertion into a small radio watch has at least two components (10, 20) contained in the casing (40) of the radio watch enclosing a gap (S) with increased magnetic field intensity (H) between them in which is fitted a coil (30) to bunch the aerial signal which forms a reception oscillator circuit (E) with a capacitor. With the separation of the components acting as an aerial, which may be structural parts of the watch casing, from the coupling coil of the reception oscillator circuit, which belongs to the electronic input stage of the reception circuit, considerable manufacturing advantages are obtained in that both structures can be made separately and optimised. When the radio watch is assembled, it is easy to optimise performance in that the position of the coupling coil can be slightly altered in relation to the two components. As several components are envisaged, it is also possible to use different ferromagnetic materials, and use can be made of this in shaping the magnetic near-field of the aerial structure.

Description

description

Small radio clock

Technical field

The invention relates to a small radio clock, according to the preamble of claim 1.

State of the art

Such a radio clock is shown, for example, in DE 3941 913 CI, where, according to the general state of the art, the coil of the long-wave antenna is wound around a ferrite core. In adaptation to the exterior of the watch, the ferrite core is widened in the direction of its ends in the form of circular or polygon segments, the ferrite core being able to carry parts of the watch case at the same time or serving as a construction element for the printed circuit board for receiving the receiving electron k.

A comparable embodiment is shown in EP 0382 130 A2, in which the antenna core is formed by the housing itself or parts of the housing and the coil is wound around partial regions of this antenna core shaped in this way.

Presentation of the invention

Both of the solutions mentioned have in common that the shapes shown or proposed for the antenna lead to antenna near fields which enforce the clockwork and in particular the electronic components of the radio clock. On the one hand, this leads to a damping of the Antenna signal, especially if there are usually unavoidable metallic parts (batteries, motors) in the immediate vicinity of the antenna. It cannot be ruled out that in the case of highly sensitive electronic components, a direct effect of the antenna near field will impair or falsify the correct evaluation of the received signal. If such impairments are to be minimized, increased electronic expenditure is required, which in turn leads to increased power consumption and, with the space for the usable battery generally limited by the housing dimensions, reduces the operating time of the radio clock without changing the battery.

Solutions specifically adapted to the shape of the respective clock, as suggested in the two publications mentioned, for the antenna lead to extremely complex production, since the antenna core with the coil is not only constructive, but also in terms of production as an interface between the electronic components on the one hand (for example are housed on a circuit board) and the other mechanical-constructive clock components can be seen (such as housing parts, motors, etc.).

The individual production of such antennas can only be carried out to a limited extent due to the shape modeled on the watch case or parts thereof, in particular the windings of the coil have to be applied in a complex manner and then the corresponding connections to the electronic components have to be made in the watch case, which leads to overlaps and difficulties since The manufacture of the electronic components, which ultimately also includes the coil, is structured differently than the conventional manufacture of the watch case with the structural components and the components for driving the hands.

The production of watches, as proposed in the cited patents, is therefore laborious and involves many sources of error. Once the coil is wound up in the space provided for it on the antenna core, there are generally no longer any options for adjusting or adjusting the resonance frequency of the resonant circuit by manipulating the coil; this would require setting options or interventions, for example on the capacitor of the receiving resonant circuit, in order to achieve an optimal adjustment by suitable adjustment. Such operations, if they can be carried out constructively at all, would consequently require additional adjustment or adjustment elements.

It is therefore an object of the invention to develop the generic long-wave antenna of the known radio clocks in such a way that the manufacture of the radio clock is considerably simplified.

According to the invention, this object is achieved in accordance with the characterizing part of patent claim 1.

The basic idea of the invention is to be seen in separating the receiving sections acting as antennas, which can be constructively components of the watch case, from the coupling coil of the receiving oscillating circuit, which, according to its purpose and function, is part of the receiving circuit of the radio clock, insofar as it is so to speak, the "electronic input stage" of the receiving circuit.

The spatial interface between the coupling coil on the one hand and the antenna structure on the other hand brings considerable manufacturing advantages in that, for example, the antenna structure can be introduced or provided without problems in the manufacture of the watch case, whereas the coupling coil can be designed as a component of an electronic circuit board or printed circuit board, which in turn can be designed separately (for example can be manufactured and optimized in a separate manufacturer). The spatial assignment of these components can be designed in a simple manner so that the coupling coil automatically in the between the two receiving sections during the final assembly of the radio clock immersed formed gap of increased magnetic field strength, whereby then the electromagnetic coupling between the antenna structure on the one hand and the receiving circuit on the other hand can be established in a casual and simple manner.

This concept also makes it possible, according to a development of the solution according to the invention, to slightly modify the position of the coupling coil in the housing of the radio-controlled clock (for example on the printed circuit board) relative to the two receiving sections, so that the received voltage can be maximized in this way.

The coupling coil is expediently wound on a core of the customary, rod-shaped type which serves as a coil carrier in order to hold the coupling coil in the region of the gap between the two ferrite bodies.

Since several reception sections are provided, it is also possible to use different materials without additional effort, which differ, for example, in permeability and low loss. For example, iron powder can be used as ferro-magnetic material, which is 50% -95% in a binder material e.g. is pressed or cast from plastic ('carbonyl iron powder').

By appropriately specifying such materials, the magnetic near field of this antenna structure can be shaped so that the field strength available in the gap between the receiving sections is maximized, for example by avoiding losses which, as in the previously known solutions, cannot be ruled out if the near field of the antenna structure interacts with metallic components inside the clock.

The scattering and tolerances that may arise when selecting different ferromagnetic materials, which influence the resonance frequency of the antenna, can, as described above, in the solution according to the invention when assembling Housing and electronics can be compensated for by fine adjustment of the coupling coil in the gap between the two ferrite bodies, since the inductance of the receiving resonant circuit and thus the resonance frequency can be changed slightly by the relative changes in position between the coil on the one hand and the gap on the other. When assembling the watch, there is therefore a simple possibility of adjustment in this production step, for example with the aid of a dip meter.

Further advantageous embodiments of the solution according to the invention can be found in further subclaims.

Brief description of the drawings

Several exemplary embodiments of a long-wave antenna for a small radio clock according to the invention will now be explained in more detail with reference to drawings. Show it:

1 and 2: two basic representations of the antenna according to the invention,

FIG. 3: a top view of a watch case with an integrated bored antenna,

FIG. 4: a variant of the antenna structure shown in FIG. 1,

5 shows a cross section through the radio clock in the plane A-A of FIG. 3,

Figure 6: a development for the reception of two transmitters.

Description of preferred embodiments

Figure 1 shows the basic principle of the antenna structure: Two molded parts 10 and 20, which are exposed to the electromagnetic field of the long wave are, the magnetic component, magnetic field H, is shown. In their place of the smallest distance, both molded parts 10, 20 form a gap S, in the area of which there is a much higher magnetic field H _s (FIG. 2), represented by the narrower field lines. In this area of the gap S, the antenna signal can be tapped by means of a coupling coil 30 and is fed to a receiving circuit E.

FIG. 2 shows a variant of the antenna structure (without showing the coupling coil), in which the molded parts 10, 20 are kept smaller and are used essentially to define the gap S. Housing parts 40A.40B doped with ferromagnetic materials, for example ferrite, serve to reinforce the magnetic field H _s in the gap S, in the example shown these are the housing end faces serving as a band stop.

In the example explained here, the wavelength of the field to be received lies in the classic long-wave range (corresponding to the frequency of the time transmitter). The only thing that is decisive, however, is that fields with sufficient field strength are received with the antenna structure according to the invention, the wavelength of which is very much greater than the antenna length; other areas of application are consequently also conceivable.

The coupling coil 30 used can have a very small diameter, since it does not have to absorb mechanical loads from the antenna structure or the housing; this results in a very low consumption of copper wire material for the windings of the coupling coil 30.

A concrete implementation of the principle of the invention in a radio clock is explained below:

FIG. 3 shows a horizontal section through a watch case 40, a double-hatched edge area 40A being designed as a bracelet connection only on the left side. Bottom 44 and circumferential Wall 45 form in the usual way a flat cylindrical interior, in which the drive parts labeled "100" in the sectional view in FIG. 2 are arranged essentially centrally for the radio clock. These drive parts 100, which convert the electronic pulses of the receiving circuit of the radio clock into the associated pointer movement, are not the subject of the present invention and can be designed, for example, according to the technical teaching of DE 35 10 861 AI or DE 35 13 961 AI.

A carrier plate 46 is held above the bottom 44 of the housing 40 and serves to receive these components 100, but also to receive a further plate with electronic components to form the receiving circuit. The latter can be, for example, a printed circuit board 41 with printed circuits and / or discrete electronic components, such as e.g. Capacitor 32, receiver unit 33, receiver quartz 34, processor 35 and clock quartz 36, and conductor tracks for connecting these components, which generate the necessary control signals for the drive units 100 (FIG. 2) from the received voltage Uιτ.

On the carrier plate 46 there is a fork-like holder 42, the two upstanding ends of which are formed in a groove-like manner, so that a coil carrier 31 passing through the coupling coil 30 is held there. The coil carrier 31 is expediently made of ferrite material and represents a short, rod-like ferrite core.

On both sides of the coil carrier 31, two mirror-like molded parts 10 and 20 are arranged on the support plate 46 as receiving sections along the wall 45 of the housing 40, the end faces 10A, 20A of which face the inside of the clock and the coil carrier 31 with the coil in the region of the edge of the watch housing 30 between them. In the direction of the opposite edge of the watch case, the distance between these opposite end faces 10A, 20A increases. End faces 10B, 20B of the molded parts 10, 20 pointing outwards are of identical shape to the inner shape of the wall 45 of the watch case, so that the shape and arrangement of the two molded parts 10, 20 shown in FIG. 1 results with the coupling coil 30 in the gap S formed between the two end faces 10A.20A at their narrowest point

The coupling coil 30 forms the receiving resonant circuit with the capacitor 32, the receiving voltage Ug can be tapped off via the capacitor 32 or forms the input voltage of the receiving and control circuit of the radio clock.

The molded parts 10, 20 are held stationary in the housing 40, for example inserted, injected or glued. In contrast, the coupling coil 30 is held with its holder 42 on the carrier plate and thus relative to the molded parts 10, 20; In the exemplary embodiment in FIG. 1, elongated holes 43, which are arranged parallel to the longitudinal axis of the watch and in which the holder 42 can be displaced parallel to the opposite end faces 10A, 20A of the molded parts 10, 20, are introduced in the holder 42.

In the alternative according to FIG. 4 (the same reference symbols correspond to the same components), the orientation of the elongated holes 43 'is arranged parallel to the coil axis. In addition, the coil carrier 31 'is immersed on both sides in corresponding bores 11', 21 ', the molded parts 10', 20 ', so that the position of the coupling coil 30' can also be changed slightly in this variant by moving its holder 42 '.

To illustrate the effect of the arrangement of molded parts 10, 20 and coupling coil 30 according to the invention, the magnetic field H outside the radio clock and the correspondingly "compressed" magnetic field H5 in the region of the gap S by the molded parts 10, 20 are also shown in the illustration in FIG. 4, that is, where the coupling coil 30 or 30 'is located. The local course of the field lines of field H5 in the area of the coupling coil 30 or 30 'naturally has inhomogeneities, and the field strength effectively acting on the coupling coil 30/30', which ultimately determines the amount of the reception voltage Urr, consequently depends both on the choice of the materials used for the molded parts 10, 20 as well as the material, preferably ferrite material of the coil carrier 31. The same applies if, in addition, the edge regions 40A of the radio clock, as shown in FIGS. 2 and 3, are also made of ferromagnetic material, so that a certain amplification of the antenna function can be achieved here. Since both these magnetic parameters and the mechanical parameters associated with the positioning of the coil are inevitably subject to manufacturing tolerances, the position of the coupling coil 30, 30 'can be adjusted with the aid of the displaceable holder 42, 42' so that an optimal tuning of the receiving resonant circuit and a Maxi ation of the input voltage U £ can be achieved by a simple adjustment process at each clock.

Figure 6 shows a further embodiment of the solution according to the invention, here a supercritically coupled band filter 38 is provided for decoupling the received signal from the gap between the two shaped bodies, so that the circuit formed thereby has two resonance frequencies - ι and <ι, which are based on the transmission frequencies of two SI and S2 transmitters can be compared.

The inventive concept of the structural assignment of electronic components to the printed circuit board on the one hand and the molded parts to the housing parts on the other hand also enables simple adjustment here, only simple modifications of the printed circuit board being required if such a two-transmitter reception is desired.

Claims

Expectations

1. Small radio clock with a long-wave antenna consisting of ferromagnetic material and receiving sections held in the housing of the radio clock, and with a coil with a capacitor for forming a receiving resonant circuit, characterized in that the coupling coil (30) for coupling the antenna signal into a gap (S) with increased magnetic field strength can be introduced between the receiving sections formed from separate molded parts (10, 20).

2. Small radio clock according to claim 1, characterized in that the position of the coupling coil (30) in the housing (40) of the radio clock to maximize the received voltage relative to the gap (S) delimiting end faces (10A, 20A) of the two molded parts (10 , 20) is adjustable.

3. Small radio clock according to claim 1, characterized in that the coupling coil (30) is wound on a coil carrier (31).

4. Small radio clock according to claim 1 and 2, characterized in that the molded parts (10, 20) in the housing (40) are integrated in a stationary manner, for example are inserted or injected like plates or disks.

5. Small radio clock according to claim 1, characterized in that for receiving at least one further transmitter, the decoupling of the received signal from the gap (S) to the receiving circuit (33) via a supercritically coupled band filter (38).

6. Small radio clock according to claim 1, characterized in that at least regions of the housing (40) are doped with ferro magnetic materials, such as ferrite, which adjoin the two molded parts (10, 20) in such a way that the field strength of the magnetic field in the gap (S) is increased.

7. Small radio clock according to claim 4, characterized in that the shaped parts (10, 20) extend in an arc or crescent shape on the edge of the housing (40).

8. Small radio clock according to claim 7, characterized in that the edges of the end faces (10A.20A) in the region of the gap (S) run parallel to one another and the distance of these end faces increases with increasing distance from the gap.

9. Small radio clock according to claim 2, characterized in that the coupling coil (30) perpendicular to the connecting axis (X-X) between the end faces (10A.20A) or parallel to this is slidably held.

10. Small radio clock according to one of the preceding claims, characterized in that the coupling coil (30) and molded parts (10, 20) are held on the printed circuit board (41) on which the electronic reception circuit of the radio clock is also located.

11. Small radio clock according to claim 3 and 9, characterized in that the coil carrier (31) extends on both sides from the coupling coil (30) to the end faces (10A, 20A).

12. Small radio clock according to claim 12, characterized in that the coil carrier (31) at its ends is forked and carried by a holder (42) which is held in the printed circuit board (41) so that it can be moved and locked.

13. Small radio clock according to one of the preceding claims, characterized in that the materials of the coil carrier (31), molded parts (10, 20) and magnetically-doped edge regions (40A) are coordinated with one another in such a way that the coil (30) in Gap (S) coupled receive voltage is maximized.