DE2600487A1 - ELECTRONIC CLOCK - Google Patents

Description

OH <Ν OI'L'INS rl. sr. DIPL-'HVh. OR. DI ^ L .- "HY". HÖGER - LEGAL RIGHTS - GRIF.SSBACH - HAECKER

.-; PATENT LAWYERS IN STUTTSART

A 41 422 b

k - 163

2nd January 1976

TIMEX Corporation
Waterbury, Conn. o6 72o, USA

Electronic clock

The invention relates to an electronic watch with an electrochromic Display unit, especially for displaying the time in an essentially conventional manner.

In recent years, displays have been developed for electronic watches in which one attempted to determine the movement of the

609835/0648 - «« «v / u. inspected

A 41 422 b

Jc - 163

Jan. 2, 1976 - 2 -

To imitate the hands of conventional clocks. In such clocks, the simulated hands are on a substrate or a plate of a liquid crystal display. In particular, the minute hands are typically on one formed on the outer circle, while the hour hands are formed on an inner circle, as is the case in US Pat. No. 3,823 and 3,540,209. A disadvantage of these known clocks is that with the selectively controllable, electrically conductive elements, which are provided in fixed positions on the clock, no display can be generated in which the hour hand and minute hand reach to the center of the dial or where the hands, as with a conventional clock, wander over each other.

Based on this prior art, the invention is based on the object of specifying an electronic watch which has a display unit in which the time display is fully electronic, i.e. without moving parts, as in a conventional one mechanical watch can be made.

This object is achieved by an electronic watch of the type described at the outset, which according to the invention thereby characterized in that a first substrate is provided on which first conductive, pointer-shaped areas for display the minutes are formed that the first substrate at least above the first conductive areas with electrochromic Material is coated that a second substrate is provided on the second conductive, pointer-shaped Areas for displaying the hours are formed that the second substrate is at least above the second conductive

609835/0648

A 41 422 b

k - 163

Jan. 2, 1976 - 3 -

Areas coated with electrochromera material is that one Counter-element for the first and second conductive areas is provided that between the first and the second Substrate an electrolyte is sealed in such a way that it is in electrical contact with the counter electrode and the electrochromic material is on the two substrates and that control devices are provided with their help selectively at the same time a potential between a first conductive area and the counter electrode and between a second conductive area and the counter electrode can be applied, so that the time information at least in hours and Minutes can be displayed.

According to the invention, a fully electronic one is obtained Clock with a display in which the movement of the hour hand and minute hand is essentially the same as that of a conventional one Clock appears. The hour hand and the minute hand preferably extend to the center of the Dial and are formed on opposing plates of an electrochromic display unit in such a way that a realistic replica of the pointers moving over one another is obtained.

Further details and advantages of the invention are provided below Explained in more detail with reference to a drawing and / or ^ are the subject of the protection claims. In the drawing show:

Fig. 1 is a plan view of a prior art wrist watch;

2 shows a plan view of a wrist watch according to the invention;

-A-

609835/0648

Λ 41 422 b

k - 163

Jan. 2, 1976 - 4 -

3 is an exploded perspective view of FIG Display unit of the wristwatch according to FIG. 2;

4 is a schematic block diagram of the logical Control circuit for the selective control of the display unit of the clock according to FIGS. 2 and 3 and

FIG. 5 is a perspective exploded view of a modified display unit for a watch according to FIG the invention.

To facilitate a better understanding of the present invention, a previously known electronic Clock will be explained with a so-called "analog" display, as shown in FIG.

It is typical of the known clock that the hands T, 2 'serving to display the time are designed as electrodes on a single layer or a single substrate, ie adjacent to one side of a liquid crystal layer. The minute hand 1 ¹ lie on an outer circle, while the hour hand 2 'lie on an inner circle.

The pointers 1 ', 2 ¹ thus appear in one plane, so that it is not possible for the pointers 1' on the outer circle to reach the center of the dial. In addition, this watch does not give the impression that the hands 1 ¹ and 2 'are at different depths, and it is also not possible, for example, to simulate the process common in a mechanical watch in which the minute hand 1' is overlaid the hour hand 2 'moved away.

603835/0848

A 41 422 b

k - 163

Jan. 2, 1976 - 5 -

From Fig. 2 of the drawing it is clear how the time display takes place in a clock according to the invention. The display unit is preferably an electrochromic display unit, in which phenomena known per se are used, such as those described in the U.S. Patents 3,704,057, 3,708,220 and 3,807,832 are described.

It exploits the effect that when a layer of an electrochromic material is between, on or over at least one pair of electrodes is arranged and / or forms a part thereof and if between the electrodes one Potential is applied, the reflection and transmission properties of the material for light are changed. If the electrodes and the electrochromic film are located on a surface of a transparent glass plate, the light transmission can be the arrangement can be changed by applying an electric field across the electrochromic material, whereby the material becomes darker, so that the light transmission of the material is reduced, for example in the area of one or more activated electrodes.

In the case of the display unit or the clock according to FIG. 2, two such substrates are now provided which, for example, consist of so-called NESA glass and on which transparent, selectively excitable electrodes to simulate a Minute hand and an hour hand are provided. The electrodes that simulate the minute hand, i, die hereinafter referred to as minute hand 1 for the sake of simplicity, are on the inside of an upper substrate, i.e., a transparent glass, placed while the electrodes, referred to as hour hands 2 for the sake of simplicity

609835/0648

A 41 422 b

k - 163

Jan. 2, 1976 - 6 -

are arranged on the inside of a lower substrate. The outer side of the upper substrate can, for example be covered with a mirror or with reflective material or with a light colored opaque material. The minute and hour hands 1,2 are so on the inside of two opposite, with electrochromic Material covered plates or substrates are provided so that when the pointer 1,2 is actuated one after the other the same visual impression is obtained as with a mechanical watch, i.e. the hands reach to the center point of the dial and lie in two planes, so that optically, for example, the impression can be created, as if one hand, for example the minute hand 1, ran over the other hand.

The details of the display unit according to the invention become explained in more detail below with reference to the perspective exploded view according to FIG. 3. You can see that a lower Substrate 3 is present, which, as mentioned above, for example made of an opaque ceramic material or a transparent Material, how NESA glass can be made and what it is based on its outside with a reflective or a light, opaque layer can be provided. The inside is with a transparent conductive layer, for example made of tin oxide, covered or covered in such a way that an electrode pattern in the form of 12 hour hands gives 2. The 12 hour hands 2 are electrically insulated from each other and individually connected by means of transparent lines 4 to a "clockwork" for generating hour hand signals. On the hour hands 2 is a layer 5 of electrochromic material

609835/0648

A 41 422 b

k - 163

Jan. 2, 1976 - 7 -

intended. The layer 5 is produced, for example, by evaporation of tungsten oxide in a vacuum for a duration such that that the desired layer thickness, which can for example be in the range of about 1 μm, results above the lower one Substrate 3 and in contact with the edge of the inside thereof is a first seal 6 made of electrically insulating Material provided in the form of a ring or a washer. Over the first seal 6 and in contact with the same is provided with a counter electrode 7, for example made of tungsten or another suitable material. The counter electrode but could also be provided on one of the substrates and, for example, as a tungsten ring outside the field of view be trained. The counter electrode 7 is designed so that an electrical connection or contact with a conductive substance, for example a liquid, conductive electrolyte is possible, which sealingly in the Display unit 19 is included. At the counter electrode 7, an electrical connection 8 is provided in order to apply an electrical potential to it from the electrical "clockwork" to be able to, over the counter electrode 7 and in contact with the ^ - The same a second seal 9 is provided, which is formed similarly to the first seal 6 described above can.

On the inside of the upper substrate 10, 60 electrodes, for example made of tin oxide, are provided, which have a pattern of 60 minute hands form 1. The 60 minute hands 1 are not electrically connected to each other, but with the help of. Lines 11 individually connected to the "clockwork" from which minute hand signals are fed to them. On or over the

609835/06 ^ 8

A 41 422 b

k - 163

Jan. 2, 1976 - 8 -

Minute hand 1 is a layer 12 of electrochromic material, for example tungsten oxide deposited. The two substrates 3,10 are sandwiched so that the Tungsten oxide layers face one another and that due to the seals 6, 9 and 6 acting as spacer elements the counter electrode 7 results in a cavity. A conductive electrolyte, for example a diluted one, is provided in the cavity Sulfuric acid. The electrolyte is transparent and provides an electrical connection between the counter electrode 7 and the layers 5 and 12 of electrochromic material, so that the electrochromic material when actuating or activating the Pointer 1, 2 becomes darker and turns blue, for example.

The pointers 1 and 2 are created by applying a potential to the respective selected pointer and by applying a positive Potential to the counter electrode 7 operated one after the other so that they are visible. The potential difference between a pointer and the counter electrode must only be used for a short time »for example for a fraction of a second, be maintained, since the electrochromic material of layers 5 and 12 is darker in the selected areas Color like a memory retains until a signal of opposite polarity between the activated pointer and the Counter electrode 7 is applied.

According to the invention, a is used as the electrochromic material Material used which, when an electric field of a first polarity is applied from a first state in which it is essentially transparent to a second state

603835/0648

A 41 422 b

k - 163

Jan. 2, 1976 - Sept.

in which it is not transparent, and which in the remains essentially in this second state until an electric field of opposite polarity is applied, to return the material to its first condition.

Fig. 4 shows a block diagram of the "clockwork" or the control device in the form of an electronic circuit which serves to apply different potentials to the display unit to be applied to selectively operate the hands used to display the time. The electronic circuit for controlling the Display unit consists essentially of a frequency standard 13, a frequency divider 14, a minute counter 15, a Hour counter 16, a decoder 17 and a driver circuit 18. Since circuits with these functions are known to those skilled in the art and are described, for example, in US Pat. No. 3,754,392, the intention is to refer to a detailed description of the individual structural units can be omitted in the context of the present application.

It should only be noted briefly that the frequency standard 13 is a quartz crystal oscillator with an output frequency of f Hz, which is a series of divider circuits 14 is supplied. A suitable divider circuit is, for example a low power flip-flop counting circuit which divides by two. Such flip-flop circuits are connected in series as counters and deliver a electrical output signal of a predetermined frequency, for example with the normal frequency of one pulse per minute. This output signal is fed to ring counters 15, 16, which store the number of pulses received as a binary number, the minute counter 15 via output lines 19 a six-

- 10 -

609835/0648

A 41 422 b

k - 163

Jan. 2, 1976 - 10 -

emits digit binary counting signal, while the hour counter 16 via output lines 20 a four-digit binary counting signal gives away. These counting signals are fed to the decoder 17 and then to the driver circuit 19 in order to set the pointers 1, 2 to selectively control the display unit, which thus provides a display corresponding to the count of the counters 15 and 16. The driver stage 18 basically supplies a control potential between the desired pointer and the counter electrode 7. For example, with the help of an electronic switching arrangement, which changes the polarity of the DC voltage enables a DC voltage source between a conductive pointer via the metallic lines 4, 8, 11 and the counter electrode 7 is applied. In this way, an actuation potential can be applied to a selected pointer so that it becomes visible. The actuation potential is between the selected pointer and the counter electrode only applied for a short fraction of the display time, as the coloring of the electrochromic material is retained until a potential (fading or erasing potential) of opposite polarity is applied. When changing the meter reading of the minute counter 15 or the hour counter 16 becomes the previously controlled minute hand 1 or hour hand 2 is controlled with the erasing potential, and the pointer or pointer (s) corresponding to the now right binary Correspond to the counting result.

5 shows an exploded perspective view of a modified form of a display unit according to the invention. The display unit according to FIG. 5 is the electrochromic display

- 11 -

609835/0648

A 41 422 b

k - 163

Jan. 2, 1976 - 11 -

Unit according to FIG. 3 is similar, with the exception that the counter electrode 22, for example, by spraying from the Melt or is formed by vapor deposition on one of the substrates, for example on the lower substrate 3 on the the hour hands 2 are also formed. The counter electrode 22 is, for example, around the hour hand 2 on the Inside of the lower substrate 3 provided so that it is in contact with a liquid electrolyte, which is enclosed in a cavity defined by the sandwich-shaped Arrangement of a seal 21 between the two substrates 3 and 10 is limited. The counter electrode 22 is mounted on the substrate 3 in such a way that it does not form part of the visible display. The counter electrode is for example arranged outside the visible display area. The electrodes that hold the hour hands 2 and the minute hands 1 are again covered with a layer 12 or 5 of electrochromic material.

Finally, it should be pointed out that the invention is not restricted to the exemplary embodiments explained above but that numerous possibilities are available to the person skilled in the art, based on these exemplary embodiments Make changes without having to leave the basic idea of the invention. In particular, there is the possibility the basic idea "of the invention also for the display of seconds to apply.

- 12 -

609835/0648

Claims (10)

Λ 41 422 b k - 163 Jan 2, 1976 - 12 - Patent claims: Electronic clock with an electrochromic display unit, in particular for displaying the time in an essentially conventional manner, characterized in that, that a first substrate (10) is provided on which first conductive, pointer-shaped areas (1) are designed to display the minutes that the first substrate (10) at least above the first conductive areas (1) is coated with electrochromic material (12) that a second substrate (3) is provided, formed on the second conductive, pointer-shaped areas (2) for displaying the hours are that the second substrate (3) at least above the second conductive areas (2) with electrochromic material (5) is coated that a counter electrode (7,22) for the first and second conductive areas (1,2) is provided that between the first (10) and the second substrate (3) a Electrolyte is sealed in such a way that it is in electrical contact with the counter electrode (7,22) and the electrochromic material (5, 12) stands on the two substrates (3, 10), and that control devices (13 to 20) are provided, with the help of which selectively simultaneously a potential between a first conductive Area (1) and the counter electrode (7,22) and between a second conductive area (2) and the Counter electrode (7,22) can be applied so that the time information can be displayed at least in hours and minutes is. - 13 - $ 09835/0648 A 41 422 b 2. Clock according to claim 1, characterized in that the number of first conductive areas for displaying the minutes is not greater than 60 and preferably is exactly 60 and that at least 12 and preferably exactly 12 second conductive areas (2) are provided for displaying the hours. 3. Clock according to claim 1 and 2, characterized in that the second conductive areas (2) for displaying of the hours extend essentially to the center of the display unit. 4. Clock according to one of claims 1 to 3, characterized in that that the counter electrode (7,22) in the circumferential direction around the visible part of the display unit is arranged around. 5. Clock according to one of claims 1 to 4, characterized in that the counter electrode (22) on one of the Substrates (3) is provided. 6. Clock according to claim 5, characterized in that the counter electrode (22) around the second conductive Areas (2) for displaying the hours is arranged. 7. Clock according to one of claims 1 to 4, characterized in that the counter electrode (7) between the first (10) and the second substrate (3) is arranged and opposite these by insulation (seals 6,9) is isolated. - 14 - 609835/0648 A 41 422 b k - 163 Jan. 2, 1976 - 14 - 8. Clock according to claim 7, characterized in that an insulation (seals 6, 9) is provided between each substrate (3, 10) and the counter electrode (7) is.. . 9. Clock according to one of claims 1 to 7, characterized in that that the counter electrode is insulated from the first and second conductive areas (1,2). 10. Clock according to one of claims 1 to 9, characterized in that the control devices (13 to 18) an oscillator (13) which has an output signal predetermined frequency supplies that controlled by the oscillator devices (14 to 18) provided are to generate electrical signals which represent time information and that electrical Connections (lines 4,8,11) are provided to the electrical representing the time information To supply signals to the first and second conductive areas (1,2) and the counter electrode (7,22) and thereby selectively activating the first and second conductive areas (1,2) for displaying the time information. 609835/0648 Blank page