The disadvantages of former similar dispositions are principally reasoned therein that the use of incandescent bulbs only permits a short lastingness in case of continuous duty and so far no projection clock coupled with a radio clock is available.

Hereto, the invention seeks to offer remedy. The purpose of the invention is to project the display of a clock comprising a projection device to any smooth surface. Therefore, the projection clock provides a moveable projection device.

Furthermore, the projection clock may provide a time display based on a clock synchronized by a DCF-77 signal-a so called radio clock-and provides an alarm. The projection device is focusable and permits a focusing of the projected image to walls having a different distance or to ceilings having a diverse height. Thus, different set-up heights of the projection clock may be compensated by adjusting the lens. The use of a super bright light-emitting diode with collimator-cage as projection light source also causes a significant increase of the lastingness of the projection light source compared to the former applied incandescent bulbs with halogen filling.

The invention solves the posed task by using an apparatus which embodies the features of claim 1.

An other advantageous embodiment of the invention is the translatability of the projecting lens in an axial direction by means of a knurled turning knob. Therewith the projecting lens is easily focusable and permits a focusing of the projected image at walls or ceilings.

The advantages of the invention are particularly based on the focusability of the lens through which the projection clock may be placed on an arbitrary level and may be used with different heights of a ceiling. Furthermore, the apparatus according to the invention permits the projection of a clock coupled with a radio clock at a wall or a ceiling.

Additional features and advantages of the invention will be discussed in the detailed description with accompanying drawings.

Brief description of the drawings: Fig. 1 shows a top view of the projection clock according to one implementation of the invention; Fig. 2 illustrates a front view of the projection clock according to one implementation of the invention.

Fig. 1 illustrates the projection clock comprising a clock 1 and a projection device 2. The projection device 2 is based on the transmitted light principle and comprises a light source 4, a miniature liquid crystal display 5 which is to be projected and a spherical lens 3. The light source 4, the miniature liquid crystal display 5 and the spherical lens 3 are sequentially arranged along the light beam permitting a projection of the miniature liquid crystal display 5 into a real image. Moreover, the projection device 2 is moveable mounted and provided with a knurled turning knob 8 permitting a focussing of the spherical lens 3. The clock 1 and the projection device are provided with two batteries 12, but optionally an AC-power unit 13 with a 3 V DC low tension side may be connected.

Fig. 2 shows a front view which illustrates the clock 1 with the projection device 2 which is moveable relative to the casing 9 of the clock 1 around the axis of rotation 17 which connects the casing 9 and the clock 1. The knurled turning knob 8 at the projection device 2 serves to translate the lens 3 in an axial direction and therewith focus the spherical lens 3. The display 11 of the clock 1 optionally provides a 24 h or a 12 h time display which may be chosen by a press switch 14. Apart from this a display 15 of the week-day and a display 16 of the date is integrated in the display 11 of the clock 9. Moreover, an alarm function, preferably providing an acoustical signal can be controlled by the press switch 14 which is integrated in the clock 1.