The invention relates to a clock display and particularly a clock display comprising a combined electronic display unit and mechanical clock hands. The clock hand has a visible state for showing the time and a transparent state used when in it is not desired to obscure the underlying display unit. The clock display may be incorporated in a portable device, such as a mobile telephone or a wrist watch.
1. A clock display comprising:
an electronic display unit;
clock hands placed in front of the display unit and connected to a hand-moving mechanism, wherein each clock hand essentially consists of an LCD display and has a visible state and a transparent state, and the display unit is adapted for non-polarized light, and the clock hands in the visible state are brought to block light and in the transparent state are brought to pass polarized light; and
a control unit controlling the hand-moving mechanism in cooperation with timing circuitry.
2. A clock display according to claim 1 , wherein the control unit is adapted to control the hand-moving mechanism to set the clock hands in a position dependent of the timing circuitry in both the visible state, and the transparent state.
3. A clock display according to claim 1 , wherein each clock hand essentially consists of two members, the two members passing polarized light in different polarization directions, the two members being adapted to overlap in the visible state and to be separated in the transparent state.
4. A clock display according to claim 3 , wherein the control unit is adapted to control the hand-moving mechanism to set the members of clock hands in a unique position independent of the timing circuitry in the transparent state.
5. A clock display according to claim 4 , wherein the members of clock hands are evenly distributed over the display unit in the unique position.
6. A clock display according to claim 5 , wherein the members of clock hands are placed as an X in the unique position.
7. A clock display according to claim 1 , wherein the clock hands are brought to the transparent state, dependent upon an information display state of the display unit.
8. A clock display according to claim 1 , wherein the clock hands are brought to the visible state, when the display unit is in a time information display state.
9. A portable device comprising a clock display comprising:
an electronic display unit;
clock hands placed in front of the display unit and connected to a hand-moving mechanism; and
a control unit controlling the hand-moving mechanism in cooperation with timing circuitry;
wherein each clock hand essentially consists of an LCD display and has a visible state, and a transparent state.
10. A portable device according to claim 9 , wherein the device is a mobile telephone, a pager, a communicator, a smart phone, a wrist watch, or an electronic organiser.