Electronic device designed to permit detachable attachment of an external memory device thereto

A wrist watch (1) is provided with a cover member (3) attached to a wrist watch case (2) by a coupling portion (3) in a openable/closable manner. A liquid crystal display device (4) to display time is incorporated in the cover member (3). A retaining section (7) for retaining a disk-like data memory is provided on the upper surface of the wrist watch case (2). The data memory in the retaining section (7) is securely held with the cover member (3) closed. Data in the disk memory (9) is read and processed by the electronic circuitry (2b) of a watch, and is sent to the liquid crystal display device (4) via a flexible circuit board (2e). The data is then converted into a time which is in turn displayed. The data memory can therefore be very easily attached or detached, and is securely held. The wrist watch itself can be made compact. Replacing the data memory with another one can provide advantages such as displaying various types of data.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an electronic device, and more 
particularly, to an electronic device so designed that an external memory, 
which has various pieces of data and programs stored therein and contains 
a control circuit or the like, can detachably be installed in this device. 
2. Description of the Related Art 
In an electronic device, particularly, a portable electronic device, such 
as an electronic notebook designed to be capable of storing telephone 
number data, address data, schedule data, etc., an internal memory cannot 
have a large memory capacity, limited by the portability and cost of the 
device. 
In this respect, electronic devices designed to permit detachable 
installation of an external memory thereto have been proposed. Among them 
is, for example, a type which allows an IC card, a ROM pack, CD (compact 
disk) or the like to be detachably attached to the electronic devices. 
This type of an electronic device that permits detachable installation of 
an external memory thereto is so designed as to permit different data and 
programs of different purposes (dictionary, name cards management, etc.) 
to be stored in different external memories and allow a user to change the 
installed external memory according to the purpose. 
In such a conventional electronic device, a memory retaining section for 
accommodating the external memory is formed in the body case of the 
device, and is to be generally covered with a cover after the external 
memory is retained in that memory retaining section. 
To provide the space for the cover, the conventional electronic device that 
is demanded to be compact has a retaining section for an external memory 
formed in a free or unused area on the side, bottom or top of the body 
case. 
In this conventional electronic device, with external memory retaining 
section formed on the side or bottom of the body case, it is inevitable 
that a user should the position of the electronic device or turn the 
device upside down to install or detach an external memory. This work of 
installation and detachment of an external memory is troublesome and 
deteriorates the usability of such an electronic device. 
If the external memory retaining section is formed on the top of the body 
case, however, it is inevitable to restrict the sizes of a key input 
section and a display section or other members, which are normally 
provided on the top of the body case. This design requires that keys be 
made smaller or the display section be designed smaller, which is not 
desirable in view of good operability and high visibility of information. 
In the conventional electronic device, the external memory and the 
retaining section have a predetermined positional relationship such that 
the external memory cannot electrically be connected to the body case 
unless the external memory is placed in a predetermined state in the 
retaining section. This conventional structure necessitates that the user 
should check the positional relation every time when placing the external 
memory in the retaining section, taking time in replacing the external 
memory with another one. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an electronic device 
which does not have the aforementioned shortcomings, and is therefore 
designed to facilitate the installation and detachment of an external 
memory as well as ensure the effective use of the surface space of the 
body case. 
To achieve this object, according to the present invention, there is 
provided an electronic device for permitting detachable installation of an 
external storage medium, comprising an external storage medium for storing 
data; a body case formed with a retaining section for accommodating the 
external storage medium; a cover member so attached to the body case as to 
open and close the retaining section, and hold the external storage medium 
retained in the retaining section when closed, the cover member provided 
with an optical display device; and electronic circuitry means for 
receiving data stored in the external storage medium and supplying a 
display signal to the optical display device. 
With the above structure, the present invention can provide large display 
space and ensure good electric connection between an external memory and 
the body case as well as significantly facilitate the attachment and 
detachment of the external memory.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferred embodiments of the present invention will now be described 
referring to the accompanying drawings. 
First Embodiment 
FIGS. 1 to 10 illustrate an electronic device according to the first 
embodiment of the present invention. 
FIGS. 1 and 2 present perspective views of a wrist watch 1 as an electronic 
device, and FIG. 3 is a cross section of the wrist watch. The wrist watch 
1 has a body case 2, and a cover (cover portion) 3 provided on a cover 
retaining section 2f on the top of the body case 2. 
The cover 3 comprises a top cover case 3a and bottom cover case 3b as shown 
in FIG. 3, and is connected via a coupling section 3c to the body case 2 
in an openable/closable manner. The cover 3 has an opening 3d formed in 
the top surface where watch glass 3e is attached, and has a display 
section 4 provided inside. The display section 4 is constituted of, for 
example, a liquid crystal display device, and is capable of displaying 
information of watch functions, such as year, month, day, day of week, and 
time, and various types of information presentable by an information 
device, such as telephone book data, name card data, schedule data and 
dictionary data. A projection 3f is provided on the side of the top cover 
case 3a, and serves to prevent the cover from opening by some shock when 
abutting on the side wall of the cover retaining section 2f of the body 
case 2. 
The body case 2 is provided with a key operation section (key input 
section) 5 and a scroll operation section 6, with a memory retaining 
section 7 formed at the lower portion of the cover 3 as shown in FIG. 2. 
The key operation section 5 includes various keys 5a, 5b, 5c and 5d, and 
the scroll operation section 6 includes a scroll key 6a. The keys 5a, 5b, 
5c and 5d of the key operation section 5 are used, for example, to adjust 
the date in watch mode and input various types of information in 
information mode. The scroll key 6a is used to instruct the up, down, 
right or left scrolling of the data displayed on the display section 4. 
The memory retaining section (retaining section) 7 is formed into a 
columnar recess, with multiple contacts (terminals) 8 arranged in a line 
at the bottom of the retaining section 7. The contacts 8 are made of a 
conductive flexible rubber member or flexible metal or the like. A 
projection 7a is formed in the center of the memory retaining section 7. 
A disk-shaped or coin-shaped information storage device 9 is disposed in 
the memory retaining section 7. The information storage device 9 (whose 
details will be given later) has a semiconductor device inside on the 
bottom of which contacts are formed. The contacts of this information 
storage device (hereinafter called as "IC coin memory") come into contact 
with the contacts 8 formed in the retaining section 7 when the IC coin 
memory 9 is housed therein. To ensure secure contact between the contact 
group of the IC coin memory 9 and the contact group 8 of the retaining 
section 7, a through-hole 9a is formed in the IC coin memory 9 so that the 
projection 7a in the center of the retaining section 7 is fitted in the 
through-hole 9a to restrict the retaining position. The body case 2 has an 
opening 2a formed in the bottom and has a printed circuit board 2c 
disposed inside, with a back cover 2d covering the opening 2a as shown in 
FIG. 3. Attached on the printed circuit board 2c is a semiconductor device 
2 b in which electronic circuitry to be described referring to FIG. 4 is 
incorporated. The printed circuit board 2c supplies a display drive signal 
to the display section 4 by means of a flexible connection board 2e. 
FIG. 4 illustrates the electronic circuitry of the semiconductor device 2b. 
To a CPU (Central Processing Unit) 11 are connected a ROM (Read Only 
Memory) 12, a RAM (Random Access Memory) 13, an input controller 14, a 
frequency dividing/time-signal output section 17, a timer section 18, a 
display controller 19, a reception buffer memory 20, a transmission buffer 
memory 21, and a communication controller 22 via a data bus 25, an 
address/control signal bus 26 and/or other various signal buses (shown). 
The ROM 12 stores a program for a watch, a program that permits the wrist 
watch 1 to function as an electronic information device, various pieces of 
numerical data and character data. The RAM 13 serves as a memory to store 
various pieces of data. A coin memory flag F to be described later is 
provided in the RAM 13. 
The CPU 11 controls the individual sections of the wrist watch 1 and the IC 
coin memory 9 according to the programs in the ROM 12 while using the RAM 
13 as a work memory, to execute a process as the wrist watch 1 and a 
process as an electronic information processing device. 
An oscillator 16 outputs a clock signal to the frequency 
dividing/time-signal output section 17. The frequency dividing/time-signal 
output section 17 frequency-divides the clock signal from the oscillator 
16 to produce a clock signal necessary for the processing in the CPU 11 
and various timing signals. 
A key input section 15 is a general representative of the various keys 5a, 
5b, 5c and 5d of the key operation section 5 and the scroll key 6a of the 
scroll section 6. The results of the operation of the individual keys of 
the key operation section 15 are output via the input controller 14 to the 
CPU 11. 
The display controller 19 supplies a display drive signal to the display 
section 4 to display various types of information based on a display 
signal from the controller 11. 
The communication controller 22 controls data transfer between the CPU 11 
and the IC coin memory 9 connected via the contacts 8 thereto. 
Particularly in this embodiment, the communication controller 22 performs 
parallel/serial conversion of data and transfers the serial data to the IC 
coin memory 9. 
The data that is transferred via this communication controller 22 to the IC 
coin memory 9 is temporarily stored in the transmission buffer 21 before 
being sent to the IC coin memory 9 via the communication controller 22, an 
input/output buffer 23 and the contacts 8. The data sent from the IC coin 
memory 9 is temporarily stored in the reception buffer 20 before being 
subjected to various processes. 
The signals which are exchanged between the CPU 11 and the IC coin memory 9 
via the contacts 8 include a control clock signal, a reset signal, data 
(I/O DATA), and signals from a power supply (vcc and ground GND). 
The IC coin memory 9 (whose structure will be described later) has 
electronic circuitry inside and is designed as indicated by the block 
diagram given in FIG. 5. 
In FIG. 5, the IC coin memory 9 is provided with a controller 30, a main 
storage section 40 and contacts 41. The controller 30 includes a CPU 31, a 
clock generator 32, a storage section 33, a transmission buffer memory 34, 
a reception buffer memory 35, a communication controller 36, an 
input/output buffer 37 and a power supply 38. The individual sections of 
the controller 30, and the controller 30 and the main storage section 40 
are connected via a data bus 60 and an address/control signal bus 70. 
In the controller 30, the clock generator 32 receives the clock signal from 
the wrist watch 1. Based on this clock signal, the clock generator 32 
produces a clock to be used by the IC coin memory 9 and outputs it to the 
CPU 31, etc. The CPU 31 receives a reset signal from the wrist watch 1, 
and controls the start or termination of a process based on this reset 
signal. Based on the programs and data stored in the storage section 33, 
the CPU 31 controls the individual sections of the IC coin memory 9, data 
exchange with the wrist watch 1, and data writing/reading to/from the main 
storage section 40. The communication controller 36 controls data transfer 
between the CPU 31 and the wrist watch 1 connected via the contacts 41 
thereto. Particularly in this embodiment, the communication controller 36 
performs parallel/serial conversion of data and transfers the serial data 
to the wrist watch 1. The data that is transferred via this communication 
controller 36 to the wrist watch 1 is read out from the main storage 
section 40 and temporarily stored in the transmission buffer 34 before 
being sent to the wrist watch 1 via the communication controller 36, the 
input/output buffer 37 and the contacts 41. The data sent from the wrist 
watch 1 is temporarily stored in the reception buffer 35 before being 
written in the main storage section 40. 
The main storage section 40, constituted of an EEPROM, stores various types 
of information, such as telephone book data, name card data, schedule data 
and dictionary data. The IC coin memory 9 exchanges the data from the main 
storage section 40 with the wrist watch 1. 
FIGS. 6 through 9 illustrate the structure of the IC coin memory 9. As 
shown in FIGS. 6 through 8, the IC coin memory 9 comprises a printed 
circuit board 43 on which a semiconductor device 42 such as an LSI having 
the circuitry as shown in FIG. 4 is mounted, a housing 44 in which the 
semiconductor-device mounted printed circuit board 43 is fitted from 
below, and a metal frame 45 which assemble the printed circuit board 43 
and the housing 44. The printed circuit board 43, housing 44 and frame 45 
have thin circular shapes, so that the IC coin memory 9 having those 
components assembled together has a circular flat shape. The printed 
circuit board 43, housing 44 and frame 45 respectively have circular 
openings 43a, 44a and 45a formed in the center, so that a through-hole 9a 
is formed in the center when they are assembled together. The through-hole 
9a becomes a reference point to position the IC coin memory 9 described 
earlier. 
On the bottom of the printed circuit board 43 are formed connector 
terminals 48 which electrically couple to the contacts 8 of the wrist 
watch 1. FIGS. 8 and 9 illustrate the structure of this printed circuit 
board 43. As shown in FIG. 8 the semiconductor device 42 is mounted at a 
predetermined position on the upper surface of the printed circuit board 
43. Many wirings 47 formed of a conductor are patterned on the top of the 
printed circuit board 43, so that when the semiconductor device 42 is 
mounted on the printed circuit board 43, the individual wirings 47 
electrically connect at their one ends to the respective terminals 48 
provided on the lower surface of the semiconductor device 42. The other 
ends of the wirings 47 are connected to through-holes 49, which are bored 
through the printed circuit board 43 in an electrically conductive manner. 
Formed on the bottom of the printed circuit board 43 are connector 
terminals 50a, 50b, 50c . . . which are associated with the through-holes 
49. As shown in FIG. 9, the connector terminals 50a, 50b, 50c . . . are 
formed concentrical with the opening 43a of the printed circuit board 43 
as the center, and are mutually insulated by a concentrical insulation 
section 51. The connector terminals 50a, 50b, 50c, . . . are to be 
connected to the terminals of the semiconductor device 42 via the 
through-holes 49 and the wirings 47. The connector terminals 50a, 50b, 50c 
. . . are exposed on the bottom of the IC coin memory 9 as shown in FIG. 
6, so that they contact the contacts 8 to be electrically coupled thereto 
when the IC coin memory 9 is installed in the memory retaining section 7 
of the wrist watch 1. As shown in FIG. 6, the housing 44 where the printed 
circuit board 43 is to be fitted has a recess 52 for housing the 
semiconductor device 42. The frame 45 for assembling the printed circuit 
board 43 and housing 44 is designed to cover the whole top portion and has 
a bent ear for supporting the housing 44 and printed circuit board 43. 
The operation of the wrist watch 1 having the above-described structure 
will be described below. FIG. 10 presents a flowchart illustrating the 
operation. 
Step A1 is a halt state, from which the flow advances to a display process 
of steps A2 and A3 or A4 every predetermined period, e.g., 1/16 sec. In 
step A2 it is discriminated whether the coin memory flag F in the RAM 13 
in FIG. 4 is on, i.e., "1." With the coin memory flag F being on, the flow 
advances to step A3 where the data sent from the IC coin memory 9 is 
displayed. When the coin memory flag F is off or "0," the information of 
the current time measured by the timer section 18 is displayed in step A4. 
When there is a key input from the key operation section 5 in step A1, the 
flow goes to step A5 where it is determined if the key input is from the 
mode select key 5d. If the key input event is originated from the mode 
select key 5d, the flow advances to step A6 where the content of the coin 
memory flag F is switched to change the mode. When it is determined in 
step A5 that the key input event has not occurred by the mode select key 
5d, the flow advances to step A7 where it is determined whether the coin 
memory flag F is on or off. When the coin memory flag F is on, the flow 
goes to step A8 where the keys 5a to 5c and the scroll key 6a are 
controlled by the control programs in the IC coin memory 9 to serve as 
keys to read or write data from or into the IC coin memory 9 or keys for 
display control. When the coin memory flag F is off, the flow advances to 
step A9 where the keys 5a to 5c are controlled by the control programs in 
the ROM 12 to serve as keys for time setup or correction or control for 
the other functions of the wrist watch 1. 
The wrist watch 1 is used with the cover 3 closed (see FIG. 1) in the above 
manner, various types of information is displayed on the display section 
4, so that the wrist watch 1 can serve as a watch or an electronic 
information device. Even with the IC coin memory 9 uninstalled in the 
retaining section 7, the controller 11 of the wrist watch 1 controls the 
individual sections according to the programs in the ROM 12 to function as 
a watch, displaying the day of the week, time, etc. on the display section 
4. 
To use this wrist watch 1 as an electronic information device, the user 
opens the cover 3, places the IC coin memory 9 in the retaining section 7, 
closes the cover 3, operates the mode select key 5d to set the memory flag 
F on, and then operates the keys 5a to 5c or the key 6a to perform various 
types of information processing. 
As this cover 3 is provided on the top of the wrist watch 1, it can be open 
and closed easily to install or detach the IC coin memory 9, thus 
facilitating the installation and detachment of the IC coin memory 9. with 
the cover 3 closed, the connector terminals 50a, 50b . . . are pressed 
against the contacts 8 to ensure stable electric contact. 
Since the projection 7a is provided in the center of the memory retaining 
section 7 and the through-hole 9a is provided in the center of the IC coin 
memory 9, it is easy to position the IC coin memory 9 when installing in 
the retaining section 7 and is possible to ensure stable electric 
connection. 
According to this embodiment, in short, the surface space of the wrist 
watch 1 can effectively be used, so that the wrist watch 1 capable of 
serving as an electronic information device can be made compact, improving 
the portability. 
Although the key operation section 5 is provided in the body case 2 in this 
embodiment, the key operation section 5 may be provided in the cover 3 as 
shown in FIGS. 11 and 12. Since the wrist watch in FIGS. 11 and 12 has the 
same structure as the wrist watch 1 according to the first embodiment, 
except for the key operation section 5, like reference numerals are given 
to like portions to avoid their detailed description. 
Second Embodiment 
FIGS. 13 to 19 illustrate another embodiment of the present invention. 
A wrist watch 100 shown in FIG. 13 is shaped almost the same as the wrist 
watch 1 shown in FIGS. 1 and 2. Like or same reference numerals are used 
to denote those sections in FIG. 13 corresponding or identical to the 
sections in FIGS. 1 and 2 so as to avoid their detailed explanation. A 
projection 7b is formed in the shape of a square pole in the center of the 
bottom of the memory retaining section 7. On the bottom of the projection 
7b opposite to the position of this projection 7b, a contact group 8b 
including eight contacts is arranged in a line perpendicular to one side 
of the projection 7b. 
An IC coin memory 101 shown in FIG. 13 is retained in the memory retaining 
section 7. 
An electronic circuitry in the wrist watch 100 is designed as shown in a 
block diagram of FIG. 14. 
In FIG. 14, connected to a controller 111 are a (Read Only Memory) 112, a 
RAM (Random Access Memory) 113, a key input section 114, a frequency 
dividing/timing-signal output section 116 and a display controller 117. 
Further, the contacts of the contact group 8b are individually connected 
to the controller 111. 
The ROM 112 stores a program for operating the wrist watch 100 as a time 
piece, a program for operating the wrist watch 100 as an electronic 
information device, or the like. In the RAM 113 having a memory area 113a, 
time data calculated by the controller 111 is stored. The RAM 113 serves 
also as a work memory for various functions. 
Using the RAM 113 as a work memory and according to the programs in the ROM 
112, the controller 111 controls the individual sections of the wrist 
watch 100 and the IC coin memory 101 to execute a process not only for a 
wrist watch but also for an electronic information device. 
An oscillator 115 generates a clock signal and sends it to the frequency 
dividing/timing-signal output section 116. The frequency 
dividing/timing-signal output section 116 then frequency-divides the clock 
signal from the oscillator 115, outputting a clock signal needed for a 
process of the controller 111 and various timing signals. 
The key input section 114 is a general representative of the keys 5a, 5b, 
5c and 5d of the key operational section 5 and the scroll key 6a of the 
scroll section 6. 
Based on a signal from the controller 111, the display controller 117 
controls the display section 4 to display various types of information. 
The IC coin memory 101 has a printed circuit board 121, a housing 122 and a 
frame 123 laminated as shown in FIGS. 15 and 16. An IC memory 124 is 
installed in the printed circuit board 121 and a printed wiring is 
provided therein as shown in FIG. 19. The printed circuit board 121 is 
covered with the housing 122 made of a synthetic resin. The housing 122 
has a chamber 125 for retaining the IC memory 124 which is installed in 
the printed circuit board 121. The housing 123 and the printed circuit 
board 121 are assembled together by the frame 123. The printed circuit 
board 121, the housing 122 and the frame 123 are formed in a disk shape 
(thin cylinder shape). The IC coin memory 101 into which these components 
are assembled is also formed in a disk shape. 
The printed circuit board 121, the housing 122 and the frame 123 as 
components of the IC coin memory 101 have square holes 121a, 122a and 123a 
in the center, respectively. These holes 121a, 122a and 123a of the 
respective components communicate with one another to provide a 
through-hole 126 of the IC coin memory 101, as shown in FIG. 15. If the 
through-hole 126 is fitted over the projection 7b in the memory retaining 
section 7 of the wrist watch 100, the installation angle and position of 
the IC coin memory 101 in the memory retaining section 7 can be set. The 
projection 7b of the memory retaining section 7 and the through-hole 126 
of the IC coin memory 101 constitute angle defining means for defining the 
installation angle of the IC coin memory 101 in the memory retaining 
section 7. 
As shown in FIG. 17, four contact groups 130a, 130b, 130c and 130d are 
formed in the lower surface of the printed circuit board 121. Each of the 
contact groups 130a, 130b, 130c and 130d are constituted respectively by 
eight contacts 131a, 131b, 131c and 131d and through-holes 132a, 132b, 
132c and 132d formed in the respective contacts. The contacts 131a, 131b, 
131c and 131d of the respective contact groups 130a, 130b, 130c and 130d 
are formed concentrical to one another in a fan shape from the center of 
the IC coin memory 101 toward the external wall. Further these contact 
groups 130a, 130b, 130c and 130d are formed at the positions opposite to 
the corresponding sides of the hole 121a. When the IC coin memory 101 is 
to be installed in the retaining section 7 of the wrist watch 101, the 
through-hole 126 of the IC coin memory 101 is fitted over the projection 
7b of the retaining section 7, ensuring that one of the contact groups 
130a, 130b, 130c and 130d of the IC coin memory 101 contacts the contact 
group 8b of the wrist watch 100. Moreover, the fitting angle of the 
through-hole 126 of the IC coin memory 101 to the projection 7b is to be 
changed by 90.degree. as needed, ensuring that one of the contact groups 
130a, 130b, 130c and 130d of the IC coin memory 101 is sequentially 
selected to come into contact with the contact group 8b. 
The IC memory 124 attached to the IC coin memory 101 is divided into four 
data memory areas 124a, 124b, 124c and 124d as shown in FIG. 18. The 
memory areas 124a, 124b, 124c and 124d constituted by, for example, an 
EEPROM are connected to their own lead lines La, Lb, Lc and Ld, 
respectively. The memory areas 124a, 124b, 124c and 124d store data about 
telephone numbers and business cards, schedule data, and dictionary data, 
for example. 
As shown in FIG. 19, the lead lines La, Lb, Lc and Ld of the memory areas 
124a, 124b, 124c and 124d in FIG. 18 are wired on the top surface of the 
printed circuit board 121 having the IC coin memory 101 thereon to the 
through-holes 132a, 132b, 132c and 132d of the contact groups, formed in 
the reverse side of the IC coin memory 101. With the lead lines La, Lb, Lc 
and Ld wired in this manner, the memory areas 124a, 124b, 124c and 124d of 
the IC coin memory 101 are connected respectively to the contact groups 
130a, 130b, 130c and 130d formed on the reverse side of the IC coin memory 
101. The 124a, 124b, 124c and 124d of the IC coin memory 101 are therefore 
connectable to the contact group 8b of the wrist watch 100 via the contact 
groups 130a, 130b, 130c and 130d. 
The action of this embodiment will now be described. 
The wrist watch 100 keeps its cover 3 closed in the normal use and displays 
various information in the display section 4. Even without installing the 
IC coin memory 101 in the retaining section 7, the controller 11 will 
control the individual sections by a program in the ROM 112, So that the 
wrist watch 100 serves as a watch and displays time data, such as the day 
of the week and time, in the display section 4. 
To use the wrist watch 100 also as an electronic information device, the 
user opens the cover 3 to install the IC coin memory 101 in the retaining 
section 7, closes the cover 3 and then operates some keys to perform 
various information processing. The flowchart of the operation in 
this-case is the same as the one shown in FIG. 10. 
In setting the IC coin memory 101 to the retaining section 7, since the 
projection 7b and the through-hole 126 both having a square cross section 
are formed respectively in the center of the retaining section 7 and the 
IC coin memory 101, the installation angle of the IC coin memory 101 in 
the retaining section 7 is defined. 
The IC coin memory 101 has memory areas 124a, 124b, 124c and 124d. The 
contact groups 130a, 130b, 130c and 130d are provided on the back of the 
IC coin memory 101 for the associated memory areas 124a, 124b, 124c and 
124d to access those memory areas. Centering around the through-hole 126 
of the IC coin memory 101, the contact groups 130a, 130b, 130c and 130d 
are formed at positions corresponding to the sides of the through-hole 
126. The contact group 8b is provided on the bottom of the retaining 
section 7 to contact the contact groups 130a, 130b, 130c and 130d of the 
IC coin memory 101. The contact group 8b is arranged only in one line 
perpendicularly to the side of the projection 7b. 
In installing the IC coin memory 101 into the retaining section 7, the 
fitting angle of the through-hole 126 of the IC coin memory 101 over the 
projection 7b is selected as needed, permitting one of the contact groups 
130a, 130b, 130c and 130d of the IC coin memory 101 to be selected as 
needed in order to contact the contact group 8b. As a result, the 
controller 111 of the wrist watch 100 can access one of the connected 
memory areas 124a, 124b, 124c and 124d, and the wrist watch 100 can serve 
as an electronic information device using information stored in one of the 
memory areas 124a, 124b, 124c and 124d of the IC coin memory 101. If the 
installation angle of the IC coin memory 101 having the memory areas 124a, 
124b, 124c and 124d to the retaining section 7 is therefore selected as 
necessary, data to be displayed by the wrist watch 100 as an electronic 
information device is easily and surely selected. Without an external 
memory prepared for each application, simply changing the installation 
angle of one IC coin memory 101 can permit the wrist watch 100 to be used 
for various purposes. The utilization and convenience of the wrist watch 
can be improved. 
In the above-described embodiment, the projection 7b in the center of the 
retaining section 7 and the through-hole 126 in the center of the IC coin 
memory 101 are used to define the installation angle of the IC coin memory 
101. The means of defining this angle is not limited to the use of these 
components. For example, a projection or a recess may be formed in the 
external wall of the IC coin memory 101, and a projection or a recess may 
be formed in the internal wall of the retaining section 7 to be fitted 
over the corresponding recess or projection. 
Third Embodiment 
FIGS. 20 and 21 illustrate another embodiment of the present invention. 
A wrist watch 300 shown in FIG. 20 has almost the same structure as the 
wrist watch 1 shown in FIGS. 1 and 2, so that like reference numerals are 
given to like sections to avoid their detailed description. The difference 
from the wrist watch 1 in FIGS. 1 and 2 lies in that a projection 151 of 
the memory retaining section 7 is formed into a pentagonal column. The 
internal circuit structure of the wrist watch 300 is the same as shown in 
FIG. 4. While an IC coin memory 160 is designed almost in the same manner 
as the one shown in FIGS. 6 and 7, a through-hole 162 is formed into a 
pentagonal shape, the same way as the projection 151. As shown in FIG. 21, 
connector terminals 161 at the bottom of a printed circuit board 163 of 
the IC coin memory 160 are arranged in a fan shape only at that position 
which faces one side of the through-hole 162. The IC coin memory 160 has 
the same internal circuit structure as what is shown in FIG. 5. 
With this arrangement, to use the wrist watch 300 as an electronic 
information device, the user opens the cover 3 to place the IC coin memory 
160 in the retaining section 7. At this time, the pentagonal columnar 
projection 151 is provided in the center of the retaining section 7, and 
the pentagonal through-hole 162 in the center portion of the IC coin 
memory 160. The IC coin memory 160 is therefore accommodated in the 
retaining section 7 by fitting the projection 151 into the through-hole 
162. In this case, since the projection 151 and the through-hole 162 are 
formed pentagonal, the former can be fitted into the latter when they 
engage with each other at a predetermined angle. When the IC coin memory 
160 is installed in the retaining section 7 only at a given installation 
angle, contacts 161 of the IC coin memory 160 come into contact with the 
contacts 8 of the retaining section 7. As a result, the contacts 161 can 
surely contact the contacts 8 of the retaining section 7 by retaining the 
IC coin memory 160 into the retaining section 7 in such a way as to fit 
the projection 151 into the through-hole 162. 
Fourth Embodiment 
FIGS. 22 and 23 illustrate the fourth embodiment of the present invention. 
A wrist watch 400 shown in FIG. 22 has almost the same structure as the 
wrist watch 1 shown in FIGS. 1 and 2, so that like reference numerals are 
given to like sections to avoid their detailed description. The difference 
from the wrist watch 1 in FIGS. 1 and 2 lies in that part of the inner 
surface of the memory retaining section 7 is a straight wall 7c and four 
rows of contacts 8c, 8d, 8e and 8f are provided at 90 degrees apart from 
each other in the memory retaining section 7. The internal circuit 
structure of the wrist watch 400 is as shown in FIG. 23. That is, the 
structure shown in FIG. 23 is substantially the same as the one shown in 
FIG. 14, the only difference lying in that the controller 11 are 
electrically connected to the contact groups 8c, 8d, 8e and 8f. 
While an IC coin memory 170 in FIG. 20 is designed almost in the same way 
as the one shown in FIGS. 15 to 19, the only difference lies in that the 
IC coin memory 170 has a straight side surface 171 which engages with the 
wall 7c of the inner surface of the memory retaining section 7. 
In this embodiment, the IC coin memory 170 can be accommodated into the 
memory retaining section 7 only when the straight side surface 171 matches 
the wall 7c of the inner surface of the retaining section 7. In the 
engaged state, a plurality of electrodes (130a, 130b, 130c and 130d in 
FIG. 17) on the bottom of the IC coin memory 170 respectively contact the 
contact groups 8c, 8d, 8e and 8f of the memory retaining section 7. 
Therefore, different pieces of data stored in the IC coin memory 170 
(those data stored respectively in the memory areas 124a to 124d in FIG. 
18) can be controlled without changing the installation position of the IC 
coin memory 170. 
The through-hole 162 is formed pentagonal, the same as the projection 151. 
As shown in FIG. 21, the connector terminals 161 at the bottom of the 
printed circuit board 163 are arranged in a fan form only at that position 
which faces one side of the through-hole 162. The internal circuit 
structure of the IC coin memory 160 is the same as shown in FIG. 5. 
The present invention is not limited to the above-described embodiments, 
but may be modified in various other manners. For instance, the contact 
groups of the memory retaining section 7 may be patterned into fan-shaped 
electrodes 180 as shown in FIG. 24. In addition, a flexible conductive 
member 182 may be placed between the contact groups of the memory 
retaining section 7 and an IC coin memory 181 to provide electric 
connection therebetween. In this case, the conductive member 182 can be 
formed by so arranging many conductive synthetic resins in an insulative 
synthetic resin as to penetrate the latter resin. 
Although the foregoing description of the individual embodiments has been 
given with reference to the case where the electronic device embodying the 
present invention is applied to a wrist watch, this invention can also be 
applied to other electronic devices, such as a small computer, portable 
telephone, paging device, electronic book and electronic notebook. 
Further, the shape and functions of the IC coin memory are not limited to 
those of the above-described embodiments. For instance, another 
non-volatile memory may be used as a data memory which is accessed for 
information storage and readout into and from a wrist watch. Furthermore, 
only a read only type memory may be provided. To use a non-volatile RAM as 
a data memory, a backup battery may be incorporated in the IC coin memory.