Sony Ericsson patents Clock Display

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.

FIELD OF THE INVENTION
The present invention relates to a clock display and, more particularly, to 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.

BACKGROUND OF THE INVENTION
Most portable devices, with an electronic display unit for displaying various information relating to the operation of the device, also incorporate a clock. Usually the time is shown on a part of the display, either as digits or as images in the form of analog clock hands.

However, many people prefer watches with mechanical clock hands to digital display systems. Even today with the currently available sophisticated digital displays, most of the wrist watches sold are provided with mechanical clock hands. However, in a portable device whose main purpose is not showing the time, mechanical clock hands will obstruct the view when the display unit is showing other information than the time.

Combined digital displays and mechanical hands are known per see. See for example EP 1046086, disclosing a watch with overlapping, separately driven mechanical and digital displays. However, in a timepiece it is not a problem that the clock hands are visible at all times.

SUMMARY OF THE INVENTION
An object of the present invention is to provide a clock display with mechanical clock hands that have both a visible state and a transparent state.

The present invention provides a clock display comprising: an electronic display unit;

clock hands placed in front of the display unit and connected to a hand-moving mechanism;
a control unit controlling the hand-moving mechanism in cooperation with timing circuitry; wherein each clock hand has a visible state, and a transparent state.

Preferably, 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.

In one embodiment, each clock hand essentially consists of an LCD display.

Suitably, 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.

In another embodiment, 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.

Preferably, 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.

Suitably, the members of clock hands are evenly distributed over the display unit in the unique position.

Suitably, the members of clock hands are placed as an X in the unique position.

Preferably, the clock hands are brought to the transparent state, dependent on an information display state of the display unit.

Suitably, the clock hands are brought to the visible state, when the display unit is in a time information display state.

The present invention also provides a portable device incorporating such a clock display.

The device may be a mobile telephone, a pager, a communicator, a smart phone, a wrist watch, or an electronic organiser.