Electronic apparatus for controlling mechanical and electrical connection to memory means

An electronic apparatus such as an electronic calculator has a detachable electric member such as an external memory card and, to avoid unfavorable effects such as destruction of memory at attaching or detaching of the electric member, the apparatus is provided with a switch which automatically turns off the power supply to the electric member when it is being attached to or detached from the apparatus.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an electronic apparatus with a detachable 
electrical member such as an external memory. 
2. Description of the Prior Art 
In the conventional electronic apparatus such as an electronic calculator 
with program function, the use of an external memory, particularly a 
detachable memory card storing predetermined program or data, is well 
known for expanding the function of the electronic apparatus and is 
extremely useful for the operator in dispensing with the cumbersome 
operation of program or data entry through the keys provided in the 
electronic apparatus itself. 
Such external memory or memory card is provided, for the purpose of 
mounting the same onto the electronic apparatus and transmitting the 
stored programs and data thereto, with plural connecting patterns which 
are maintained in electric pressure contact with a connector having plural 
contacts provided in the electronic apparatus. 
However, attaching or detaching of the memory card, if conducted while the 
power supply is continued, may lead to the destruction of the program or 
data stored in the memory card or even of the processing circuitry in the 
electronic apparatus, since the connector functions as a spring and causes 
unstable chattering phenomenon. 
SUMMARY OF THE INVENTION 
In consideration of the foregoing, an object of the present invention is to 
provide an electronic apparatus in which an electrical member, 
constituting an external memory for supplying programs or data, can be 
attached or detached while it is completely separated from the power 
supply of the electronic apparatus. 
Another object of the present invention is to provide an electronic 
apparatus capable of completely avoiding destruction of data at the 
detaching of an electrical member. 
Still another object of the present invention is to provide an electronic 
apparatus with a detachable electrical member such as an external memory, 
wherein said apparatus is provided with a cover member for holding the 
external memory in the apparatus, first switch means engageable with the 
cover member and movable in two positions, and second switch means 
slidable in a direction perpendicular to the moving direction of the first 
switch means and adapted to prohibit the movement of the first switch 
means to a second position. 
The foregoing and still other objects of the present invention will become 
fully apparent from the following description of the preferred embodiments 
.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIGS. 1 to 3 show an example of memory card attach/detaching mechanism of 
known electronic apparatus. 
In FIGS. 1 and 2, a case 1 of the electronic apparatus is provided with a 
recess 3 for accommodating a memory card 2. At the bottom of the recess 3 
a pressure contact connector 5 with plural contacts 4 is provided in such 
a manner that the contacts 4 protrude slightly from the bottom of the 
recess 3. On an end face of the recess 3 are two rectangular apertures 6, 
while on an opposed face there is provided, in the case 1, a switch 
functioning as a power switch and a lock mechanism for the memory card as 
will be explained later. A slidable knob 7 protrudes from an aperture 1a 
provided on a lateral face of the case 1. 
The memory card is formed as a flat box, which is provided on a face 
thereof with plural contact patterns 8 in such a manner as to be connected 
with the contacts 4 of the connector 5 formed on the bottom of the recess 
3. In FIGS. 1 and 2 there is also shown a plate-shaped cover 9 for the 
memory card. On a shorter end the cover 9 is provided with two projections 
10 to be fitted in the rectangular apertures 6 formed on an end face of 
the recess 3. On the opposed shorter end the cover 9 is provided with a 
downwardly extended projection 11 with a locking aperture 11a for engaging 
with a projection of the slidable knob provided inside the case 1. 
More specifically, as shown in FIG. 3, the slidable knob 7 has an integral 
projection 12 for engaging with the locking aperture 11a of the projection 
11 of the cover 9. The slidable knob 7 is further provided with an 
integral leaf contact 13 made of a conductive material. There is also 
shown a printed circuit board 14 provided in the case 1 and having circuit 
patterns for performing various processings. 
In the above-described device the mounting of the memory card 2 onto the 
case 1 is achieved by the steps of inserting the memory card 2 into the 
recess 3 of the case 1, fitting the projections 10 of the cover 9 with the 
apertures 6 in the recess 3, rotating the cover 9 about the engaging 
position between the projections 10 and apertures 6 to depress the memory 
card 2 against the bottom of the recess 3, and moving the slidable knob 7 
toward the memory card to engage the projection 12 of the knob with 
locking aperture 11a of the projection 11 of the cover 9, thus locking the 
cover 9 to the case 1 and maintaining the contact patterns 8 of the memory 
card 2 in contact with the contacts 4 of the connector 5. 
The detaching of the memory card 2 from the case 1 is achieved by moving 
the slidable knob 7 away from the memory card 2 to disengage the 
projection of said knob from the locking aperture 11a of the projection 11 
of the cover 9, whereby the memory card 2 is pushed upwards by the elastic 
force of the contacts 4 of the connector 5, and then extracting the 
projections 10 of the cover 9 from the apertures 6 of the recess 3 so that 
the cover and the memory card 2 may be detached from the case 1. 
In the above-described structure, the leaf contact 13 integral with the 
slidable knob 7 also moves by the motion thereof to disengage the 
projection 12 from the locking aperture 11a for detaching the memory card 
2. Consequently it is possible to detach the memory card 2 while the power 
supply is cut off, if the patterns on the printed circuit board 14 are 
formed in such a manner as to turn off the power supply of the electronic 
apparatus 1 by the movement. 
The mounting of the memory card 2 to the case 1 is achieved by placing the 
memory card 2 in the recess 3, attaching the cover 9 and moving the 
slidable knob 7 to engage the projection 12 thereof with the locking 
aperture 11a of the projection 11 of the cover 9 thereby securing the 
cover 9 to the case 1. 
Thus, the power supply to the electronic apparatus is turned on only after 
the memory card 2 is securely mounted to the case 1 if the patterns of the 
printed circuit board 14 are so constructed that the power supply is 
turned on by the movement of the leaf contact 13. 
In this manner a single slidable knob can be used for turning on and off 
the power supply and for locking and unlocking the cover, thus avoiding 
the destruction of the electrical member such as the memory card. 
In the above-described device, however, if the slidable knob 7 is moved 
quickly at the detaching of the memory card 2, unstable contact state 
between the contact patterns 8 of the memory card 2 and the contacts 4 of 
the connector 5 appears practically simultaneously with the turning off of 
the power supply in the electronic apparatus 1. If the power supply 
circuit contains a power accumulating element such as a capacitor, the 
actual power cut-off is delayed from the movement of the slidable knob 7. 
Therefore the destruction of the programs or data in the memory card may 
result by the unstable contact between the contact patterns 8 of the 
memory card 2 and the contacts 4 of the connector 5. 
FIGS. 4 to 8 illustrate an embodiment of the present invention capable of 
rectifying the drawback of the foregoing device, wherein components which 
are the same as or corresponding to those shown in FIGS. 1 to 3 are 
represented by the same numbers and will be omitted from the following 
description. 
FIG. 4 is an external perspective view of the case 1, wherein a switch knob 
15 for turning on/off the power supply and for locking/unlocking is fitted 
in a slot 15a so as to be slidable in the longitudinal direction of the 
cover 9, while a locking knob 16 is fitted in a slot 16a of the case 1 so 
as to be slidable in a direction perpendicular to the sliding direction of 
the knob 15. 
FIG. 7 is an exploded perspective view of a power/lock switch of this 
embodiment formed on a block 15b. On a lateral face of the block 15b there 
is integrally formed an arc-shaped element 18a, with a click projection 18 
at the center thereof, having elasticity in a direction perpendicular to 
the sliding direction of the knob 15. 
Also on an opposed face to the click projection 18, there is formed a 
projection 21 and an L-shaped hook 23 which extends from the projection in 
the sliding direction and is formed slightly lower than the upper surface 
of the block 15b. 
The locking knob 16 is formed on a block 16b which is fitted between the 
projection 21 and the hook 23 of the aforementioned block 15b. 
The block 16b is further provided, on a lateral face thereof facing toward 
the click projection 18, with an L-shaped stopper 20 extending under the 
block 15b. 
The block 16b is biased by a spring 19 toward the block 15b. Further a 
circuit pattern 22 is formed on the printed circuit board 14. 
The following explains the assembling of the switch and spring 19. In the 
case 1 there is formed a frame 1b slidably accomodating the blocks 15b, 
16b and provided with three click grooves 17 for engaging with click 
projection. The block 16b is fitted in said frame 16 so as to be 
perpendicular to the moving direction of the block 15b, and the spring 19 
is fitted to bias the block 16b toward the block 15b. The assembly is 
conducted in such a manner that the upper faces of the blocks 15b and 16b 
are coplanar, and that the lower faces of the hook 23, stopper 20 and 
blocks 15b, 16b are coplanar. 
In the following explained is the method of use and function of the present 
embodiment described above. 
FIG. 5 shows a plan view of the switch in a state where the memory card 2 
is mounted in the case 1, and the projection 12 protrudes from the case 1 
into the recess 3 to engage with the locking aperture 11a of the 
projection 11 of the cover 9. 
At the same time the click projection 18 integral with the block 15b 
engages with one of three click grooves 17 closest to the recess 3. When 
detaching the memory card 2 and the cover 9 from the case 1, the knob 15 
is moved, from the state shown in FIG. 5, away from the recess 3 as shown 
in FIG. 6. FIG. 6 shows a step of turning off the power supply of the 
electronic apparatus while the cover 9 is still maintained in engagement 
with the projection 12. In this state the projection 12 of the block 15b 
still protrudes into the recess 3 and engages with the cover 9, so that 
the memory card 2 is still in contact with the contacts 4 of the connector 
5. In this state the stopper 20 projecting from the block 16b engages with 
the projection 21 of the block 15b, thus hindering further movement 
thereof in a direction away from the recess 3. Also the click projection 
18 of the block 15b engages with the central one of three click grooves 17 
formed on the case 1, thus defining a step in the movement of the block 
15b. The circuit pattern 22 formed on the printed circuit board 14 is 
formed in such a manner that the power supply PS in the electronic 
apparatus 1 is cut off in this state by relative positioning of the 
pattern 22 and the leaf contact 13 provided on the block 15b. After the 
power supply is cut off in this manner, the knob 16 is moved in a 
direction away from the knob 15, thus disengaging the stopper 20 from the 
projection 21. Then the block 15b is further moved away from the recess 3 
of the case 1 to reach a state shown in FIG. 8. 
In the state shown in FIG. 8, the projection 12 of the block 15b no longer 
protrudes in the recess 3 and is therefore disengaged from the locking 
aperture 11a of the projection 11 of the cover 9, thus enabling the 
removal of the cover 9 and memory card 2 from the case 1. In this state 
the click projection 18 of the block 15b engages with one of three click 
grooves 17 farthest the recess 3. 
The hook 23 formed on the block 15b is present in order to avoid a one-step 
movement of the knob 15 from the state shown in FIG. 5 to the state in 
FIG. 8 after the knob 16 is shifted away from the knob 15 against the 
force of the spring 19, thus disengaging the stopper 20 from the 
projection 21. More specifically, in the state shown in FIG. 5, the hook 
23 engages a lateral face of the block 16b opposite to the block 15b to 
prohibit the movement of the block 16b. In the state shown in FIG. 6, the 
hook 23 formed integral with the block 15b is disengaged from the block 
16b by the movement of the block 15b to the position shown in FIG. 6, so 
that the block 16b is rendered slidable thus achieving the aforementioned 
effect. 
Now there will be explained the method of use and function in case of 
mounting the memory card 2 and the cover 9 onto the case 1. After the 
cover 9 is mounted, the knob 15 is moved toward the recess 3, from the 
state of FIG. 8 to the state of FIG. 6, whereupon the block 16b is biased 
toward the block 15b by the compressed spring 19 and reaches a lateral 
face of the block 15b next to the projection 21. 
In this state the projection 12 of the block 15b engages with the locking 
aperture 11a of the projection 11 of the cover 9, thus securing the cover 
9 and the memory card 2 to the case 1. Then the block 15b is further moved 
to the state shown in FIG. 5 whereby the bent portion of the leaf contact 
13 is brought into contact with the pattern 22 to restore power supply to 
the electronic apparatus 1. 
The above-described embodiment is capable, in an electronic apparatus with 
a detachable electrical member such as a memory card functioning as an 
external memory, of completely preventing destruction of the programs and 
data stored in the memory card or of processing circuitry in the apparatus 
resulting from unstable connection of the memory card and electronic 
apparatus, since the attaching or detaching of the memory card takes place 
in a state that the power supply to the electronic apparatus is completely 
cut off. 
As explained in the foregoing, the present invention enables, in an 
electronic apparatus with a detachable electrical member such as a memory 
card functioning as an external memory, to completely prevent destruction 
of the programs or data stored in the memory card or of the circuitry in 
the apparatus since the power supply of the apparatus is completely cut 
off at the attaching or detaching of the memory card.