GB2072896A - Electronic Timepiece - Google Patents

Abstract

An electronic timepiece has electronic components including an integrated circuit (70), a battery (64) for supplying electric power to said integrated circuit, analog display means (20) including an electromechanical transducer (step motor) driven by a signal from said integrated circuit (70), a wheel train (68) for transmitting the mechanical displacement of said electromechanical transducer to hands (20a, b) for indicating the time, and a dial (20c), and an annular electro-optical display device (18). The analog display portion (20) is disposed in a central portion of the timepiece, and the annular digital display portion (18) is disposed around the periphery of the analog display portion (20). The battery (64) and the integrated circuit (70) extend into both said analog display and digital display portion regions. <IMAGE>

Description

SPECIFICATION Electronic Timepiece Background of the Invention This invention relates to a dual display multifunction timepiece of the crystal-controlled oscillator type, which timepiece has a single movement that is equipped with an analog display mechanism that relies upon time-indicating hands, and with a digital display mechanism and pattern display mechanism which rely upon an electro-optical display device such as a liquid crystal cell or electrochromic cell.

Electronic wrist watches of the type equipped with a crystal-controlled oscillator have undergone remarkable development. They are well known for their high reliability and accuracy, low cost and attractive design, and now occupy the major portion of the wrist watch market.

Crystal timepieces may be classified into those having an analog display relying upon hands, those having a digital display relying upon a liquid crystal display cell, and those having a dual display (analog-digital display) which incorporates both an analog and digital display. Timepieces with an analog display have an extemely attractive design (they are rich in design variety) and are highly fashicnable, and they are corrected through a simple method and permit both elapsed time and remaining time to be read with ease. It is difficult, however, to furnish such timepieces with a multiplicity of functions.

Timepieces with a digital display have a simple internai mechanism, are low in cost and permit the current time to be read directly in numerical form. In addition, they can readily be provided with a multiplicity of functions such as a perpetual calender, stop-watch, timer and alarm. Such timepieces are disadvantageous, however, in that they do not exhibit the fashionable sense possessed by hands and make it difficult to ascertain elapsed time and remaining time. The timepieces having a dual display give prominence to functionality and design and exploit the advantages of both the analog and digital displays while compensating for their shortcomings.

The dual display wrist watches that have so far been proposed and partially marketed have little commercial appear in terms of design because in many of then a rectangular liquid crystal display cell is merely incorporated within a portion of an analog dial, making such timepieces poor in design variety. Although some of the marketed timepieces have interesting designs in which an analog module is disposed within a cutaway portion of an irregular octagonal liquid crystal display cell, there is little harmony and correlation between the analog and digital displays.

Specifically, these timepieces are disadvantageous in that the hands of the analog portion are not located in the center of the timepiece and are a little too short, and in that it is difficult to recognize the mode in which the digital portion is operating.

Summary of the Invention According to the present inention, there is provided an electronic timepiece powered by a battery, comprising: a quartz oscillator to provide a time base signal; an integrated circuit chip to provide a time information signal in response to said time base signal; analog display means including electro-mechanical transducing means; wheel train means coupled to said transducing means and driven by said transducing means; an annular electro-optical display device; said analog display means including an analog display portion disposed in a central portion of the timepiece, and a digital display portion formed by the annular electro-optical display device being disposed around a periphery of the analog display portion; said battery and said integrated circuit extend into both said analog display and digital display portion regions.

Brief Description of the Drawings Fig. 1 is a top view which shows the encased state of a dual display multifunction wrist watch according to the present invention; Fig. 2 is a plan view of an annular liquid crystal display cell; Fig. 3 is a cross-sestional view of the annular liquid crystal display cell; Fig. 4 is a bottom view (display panel side of a plan view showing a module in the assembled state; Fig. 5 is a top view (case back-cover side) of a plan view showing the module in the assembled state; Fig. 6 is a plan view of the esssential portions of an analog block; Fig. 7 is a cross-sectional view of the essential portions of the analog block; Fig. 8 is a cross-sectional view of the essential portion of a battery; and Fig. 9 is a cross-sectional view showing the essential portion of a switch.

Description of the Preferred Embodiments Fig. 1 is a top view which shows the encased state of a dual display multifunction wrist watch according to this invention. A crystal glass 10 is fixed to a case band 12 through a packing 14.

Included in the crystal glass 10 is a display panel 16, which is constructed of an annular liquid crystal display cell 1 8 and an analog display portion 20. The annular liquid crystal display cell 18 is provided with a mode pattern display section 22, an annular display section 24 and a numeric display section 26. The analog display portion 20 comprises of a minutes hand 20a, an hours hand 20b and a dial 20c.

A first switch (S) 28, a second switch (S,) 30, a third switch (S3) 32 and a fourth switch its4) 34 are disposed for the purposes of correcting the time, selecting the mode, etc.

Fig. 2 is a plan view of the annular liquid crystal display cell 1 8. The mode pattern display section 22 display mode patterns of letters or marks corresponding to the respective modes of timepiece information and function information, and which has time mode 22a, a date mode pattern 22b, an alarm mode pattern 22c, a chime mode pattern 22d, a timer mode pattern 22e, a stop watch mode pattern 22f, and letters "LAP" 22g indicative of the lap time for the stop watch.

The annular display section 24 is composed of sixty rectangular segments arranged annularly, 2401, 2402, 2403,2404,... 2457, 2458,2459 and 2460, and displays as patterns the timepiece information in seconds and function information indicative of a function which is in operation.

The numeric display section 26 has a first numeric display member 2601, a second numeric display member 2602, a third alphanumeric display member 2603 and a fourth alphanumeric display member 2604 each of which consists of a plurality of bar segments arranged in the form of a figure-eight, and "AM" and "PM" marks 26a and 26b, a "minute" mark 26c, a "second" mark 26d, a "1/100 second" mark 26e and a "colon" mark 26f which are service marks. In the numeric display section 26, the calendar information (date, day of the week) of the timepiece information are displayed by numerals and letters, the hour and minutes of the timepiece information are displayed by numerals, and the function information such as addition, subtraction and alarm time are displayed by numerals.

The annular liquid crystal display cell 18 includes an opening 1 8a in the form of a square hole, in which the analog display portion 20 can be received. A solder-sealing portion 36 is formed in such a manner that, after a liquid crystal substance has been injected, it is sealed by soldering.

Fig. 3 is a sectional view of the annular liquid crystal display cell 18. On the lower surface of an annular upper glass plate 40, a segment electrode 42 is formed by coating the entire surface with a conductive film, the principle constituent of which is indium oxide In203 or tin oxide SnO2, and thereafter patterning the film by photoetching process. Likewise, on the upper surface of an annular lower glass plate 44, a common electrode 46 is formed by patterning a conductive film. The annular upper glass substrate 40 and the annular lower glass substrate 44 are formed with alignment layers on the electrode surface sides in directions orthogonal to each other by a SiO slant evaporation process or rubbing process.On the perimetric parts of the electrode surface sides of these substrates, sealing layer 48 consisting of low-melting glass, epoxy resin or the like are formed so as to provide a gap of approximately 8 microns between the substrates. P-type nematic liquid crystal molecules which are dielectrically positive are injected and sealed in the interspace defined by the substrates and the sealing layers, to form a twisted liquid-crystal layer 50 therein.

An upper polarizer 52 and a lower polarizer 54 are bonded into place, and a scattering reflector 56 is provided. The twisted liquid-crystal layer 50 normally has the property of rotating its polarization plane. However, when a voltage is applied across the segment electrode 42 and the common electrode 46, the twisted liquid crystal layer 50 undergoes a change in molecular arrangement and its polarization plane is no longer capable of rotation. This operating system is called the "TN-FE mode", and is suitable for wrist watches because of low operating voltage, low power dissipation and the capability of matrix drive. This mode of operation is suitable in the present invention as well.

Figs. 4 and 5 are a bottom (display panel side) view and a top (case back-cover side) view of assembly plan views of a module 60 of the dualdisplay multifunction wrist watch of this invention with the case detached, respectively. Fig. 6 is a plan view of the essential portions of an analog block 62.

Figs. 7, 8 and 9 are fragmentary sectional views of the module 60 with the case included, in which Fig. 7 shows the essential portions of the analog block 62, Fig. 8 shows portions of and around a battery 64 and Fig. 9 shows portions of and around the switch 28.

Referring to Fig. 4, in a region extending under the annular liquid crystal display cell 18 and inside the opening 18a, a drive coil 66 for driving a converter and a wheel train 68 are disposed, and the battery 64 and an IC 70 to provide a time information signal in response to a time base signal are indicated by dotted lines. In this manner, the coil, the wheel train etc. are arranged together in the central part of the timepiece without overlapping the battery 64 and the IC 70 and while avoiding a circuit block.

Fig. 5 illustrates the planar arrangement of a subminature quartz oscillator 72 to provide the time base signal, a trimmer capacitor 74 for adjusting frequency, booster capacitors 76 for boosting the voltage of the battery 64 up to a liquid crystal driving voltage, a booster coil 78 for a buzzer, a capacitor 80 for the buzzer, a transistor 82 for the buzzer, and a resistor 84 for the buzzer. As apparent from Fig. 8, the various circuit elements are arranged around the analog block 62.

Fig. 6 is an enlarged view of the analog block 62. A magnetic field generated by the coil 66 passes through a stator 90 and rotates a rotor 92.

The rotor 92 is rotated 1800 by one pulse impressed upon the coil 66, and the rotational motion is transmitted to a third wheel 94 and decelerated. In succession, the rotational motion of the third wheel 94 is transmitted to a center wheel 96 and decelerated, the rotational motion of the second wheel 96 is transmitted to a minute wheel 98 and decelerated, and the rotational motion of the minute wheel 98 is transmitted to an hour wheel 100 and decelerated.

Referring to Fig. 7, the various rotating parts are assembled in a manner to be held between an upper plate 102 and a lower plate 104.

The center wheel 96 consists of a minute hand arbor 106 and a gear. It has the number of teeth of its gear set so as to rotate one revolution in sixty minutes.

The minute hand 20a is mounted on the front end of the minute hand arbor 106, and effects a minute indication as in the usual manner.

The hour wheel 100 consists of an hour hand arbor 108 and a gear, and rotates one revolution in twelver hours. The hour indication is therefore effected by the hour hand 20b which is mounted on the front end of the hour hand arbor 108.

The upper plate 102 and the lower plate 104 are fixed to each other by supporting columns and screws in three supporting column positions 110 shown in Fig. 6. Fig. 7 illustrates the sections of the crystal glass 3, the dial 20c, a dial spacer 120, a circuit board 122, a device cover 124, a piezoelectric element 126, a vibrating plate 128 and a back cover 1 30. The piezoelectric element 1 26 and the vibrating plate 128 construct the buzzer.

Fig. 8 illustrates the sections of the case band 12, the packing 14, the crystal glass 10, the annular liquid crystal display cell 18 and the dial plate 20c. A decorative ring 1 32 is arranged between the annular liquid crystal display cell 18 and the dial plates 20c. As shown in Fig. 1, the decorative ring 132 is printed with numerals 5, 10, 15,20, 25, 30, 35,40, 45, 50, 55 and 60.

The annular liquid crystal display cel 18 and the circuit board 122 are connected together by a conductive rubber 134. The IC chip 70 is bonded to the circuit board 122 by wires 136 and is covered with a sealing frame 137, into which a potting resin 138 is poured to protect the wire bonding portion. A circuitry supporting pedestal 140, a circuitry supporting plate 142, the device cover 124, the piezoelectric element 126, the vibrating plate 128 and the back cover 130 are disposed as shown in Fig. 8. A rubber packing 144 is interposed between the battery 64 and the back cover 130, and enhances the sounding effect of the buzzer. A clearance 146 of approximately 200 microns is provided between the vibrating plate 128 and the back cover 130, so that the vibrations of the vibrating plate 128 are transmitted into the atmosphere.The rear cover 1 30 and the vibrating plate 128 are made waterproof with respect to the case band 12 by an 0-ring 148.

As shown in Fig. 9, the first switch 28 referred to by way of example is made waterproof by a small-sized 0-ring 1 50. When the first switch 28 is depressed, it pushes a switch spring 1 52 formed by the front end of the circuitry supporting plate 142 and connects this switch spring 1 52 to a conductive side portion 1 54 provided at an edge of the circuit board 122. The circuitry supporting plate 142 is connected to a side surface of the battery 32 by a side-pressing spring 149 shown in Fig. 8, and lies at a plus (+) potential. Accordingly, upon pressing the first switch 28, the conductive side portion 1 54 is brought to the plus (+) potential and receives a switching input. Those parts of the crystal glass 10 which overlie the decorative ring 132 and a cell holder 1 56 for compressing the conductive rubber 1 34 are provided with printed panel covering parts 158, whereby panel cover is formed.

Claims (6)

Claims

1. An electronic timepiece powered by a battery, comprising: a quartz oscillator to provide a time base signal; an integrated circuit chip to provide a time information signal in response to said time base signal; analog display means including electro-mechanical transducing means; wheel train means coupled to said transducing means and driven by said transducing means; an annular electro-optical display device; said analog display means including an analog display portion disposed in a central portion of the timepiece, and a digital display portion formed by the annular electro-optical display device and disposed around a periphery of the analog display portion; said battery and said integrated circuit extending into both said analog display and digital display portion regions.

2. An electronic timepiece according to claim 1, in which the electrochemical transducing means and wheel train means are disposed in a region of the analog display portion without said battery and said integrated circuit overlapping each other.

3. An electronic timepiece according to claim 1 , further comprising electronic components disposed outside of said analog display portion without said battery and said integrated circuit overlapping each other.

4. An electronic timepiece according to claim 1, in which the battery, integrated circuit and electromechanical transducing means are arranged at three apices of a triangle whose center is the center of the timepiece.

5. An electronic timepiece according to claim 1, in which the battery and integrated circuit chip are disposed substantially in one of two regions of the timepiece defined by a straight line passing through the center of the timepiece.

6. An electronic timepiece substantially as hereinbefore described with reference to the accompanying drawings.