JP2002190000A - Recording medium and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To grasp the residual capacity of a recording medium without accessing the recording medium. SOLUTION: A rewritable display part 12 is provided on the outer surface of a memory card 10, and information showing the residual quantity of the memory card 1 is displayed on the display part 12. A film that does not consume power except when information is rewritten is desirably applied to the display part 12 like a polymer nematic liquid crystal film. For display, numeric characters may be used, graphic display such as a bar graph and a circle graph may be used, and the both the numeric characters and the graphic display may be used. In equipment in which the memory card 10 is used, the residual quantity display of the display part 12 may be rewritten each time data is written on the card or erased from the card, and the residual quantity display may be collectively rewritten when the card is ejected. Also, the memory card 10 itself may be provided with a means for calculating residual quantity and a means for rewriting the residual quantity display.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a recording medium for recording electronic data, and an electronic apparatus for reading and writing information using the medium.

[0002]

2. Description of the Related Art Generally, a digital camera records image data obtained by photographing on a removable medium such as a memory card. The digital camera has a function of displaying information on how many images can be recorded on the display unit according to the remaining capacity of the memory card,
The user (photographer) can check the number of shootable images (Japanese Patent Laid-Open No. 2000-175146).
issue).

[0003]

However, conventionally,
The memory card alone cannot tell the remaining capacity. For example, if you have to bring a memory card for additional recording with a digital camera in a bag or the like, you should quickly determine which memory card has enough free space Was difficult.

[0004] Although an IC card having a display section has been proposed (Japanese Patent Application Laid-Open No. 7-31826 and Japanese Patent No. 2639528), the remaining capacity display is not disclosed.

The present invention has been made in view of such circumstances, and provides a recording medium capable of grasping the remaining capacity of the medium alone without accessing the recording medium. The purpose is to provide equipment.

[0006]

In order to achieve the above object, a recording medium according to the present invention is provided with a rewritable display section on the outer surface of the recording medium, and the display section has a remaining capacity of the recording medium. Is displayed in advance.

According to the present invention, it is possible to grasp the remaining capacity of a recording medium alone without inserting the recording medium into an electronic device. The display may be numerical,
A graphic display such as a bar graph or a pie graph may be used, or these may be used in combination.

In one aspect of the present invention, the display unit displays the remaining capacity in a state where the display content is rewritten by an electronic device using the recording medium and the recording medium is removed from the electronic device. It is characterized by being maintained.

It is desirable that the display unit does not consume power except for rewriting, such as a ferroelectric liquid crystal display.

In view of the fact that the recording medium of the present invention can be used for an electronic device having no display rewriting function, a recording medium according to another aspect of the present invention includes a part of the rewritable display unit or A determination means for determining whether or not the data content stored in the recording medium has been rewritten; a self-rewritable area rewritable by the recording medium itself; Display control means for displaying, in the self-rewritable area, information indicating that the content of the media has been rewritten, when it is determined that the media has been rewritten.

In the case of an electronic device having a display rewriting function, the display contents of the self-rewritable area may be updated when the remaining capacity display is updated. The display of the rewritable display area is maintained, and it is possible to know that the data content of the recording medium has been rewritten after removing the recording medium.

According to still another aspect of the present invention, there is provided a recording medium, comprising: calculation means for calculating a remaining capacity; display control means for changing a display of the remaining capacity on the display unit based on a calculation result of the calculation means; It is characterized by having.
By managing and displaying the remaining capacity on the recording medium itself without using an electronic device, it is possible to always accurately display the remaining capacity.

Further, in order to provide an electronic device using the recording medium of the present invention, the electronic device according to the present invention comprises: a medium inserting section into which the recording medium is inserted; and a recording medium inserted into the medium inserting section. Media reading means for reading and writing data, memory management means for grasping the remaining capacity of the recording medium, and display rewriting means for rewriting the display of the remaining capacity on the display unit according to the memory management means. .

An electronic device according to one aspect of the present invention has a control means, and the control means displays the remaining capacity by the display rewriting means every time data is written or erased by the medium reading means. The display rewriting means is controlled so as to be rewritten.

According to another aspect of the present invention, there is provided an electronic apparatus including an ejection unit for ejecting a recording medium from the medium insertion unit, and a control unit, wherein the control unit is configured to eject the recording medium by the ejection unit. The display rewriting means is controlled so that the display rewriting means rewrites the display of the remaining capacity.

The ejecting means may be either manual or electric, but in order to stably perform the rewriting operation by the display rewriting means, an electric driving means such as a motor must be provided so that the discharging speed can be controlled. The power eject used is preferred. Further, as an example of the electronic apparatus, an electronic camera including an imaging unit that converts an optical image into an electric signal and a recording unit that records image data acquired via the imaging unit on a recording medium may be used. is there.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a recording medium and an electronic device according to the present invention will be described below with reference to the accompanying drawings.

FIGS. 1A to 1D show examples of a recording medium according to an embodiment of the present invention. The recording media 10, 20, 30, 40 shown in these drawings are:
Both are removable media that can be accessed randomly, and have rewritable display units 12, 2 on their outer surfaces.
2, 32, and 42. And these display units 1
The remaining capacity information is displayed at 2, 22, 32 and 42.

A card-type recording medium (hereinafter, referred to as a memory card) 10 shown in FIG. 1A has a connector 14 for electrically connecting to a personal computer or other electronic equipment (not shown). (The upper end surface in FIG. 1), and the rewritable display unit 12 is provided on the flat surface of the card. Memory card 2 shown in (b)
In 0, a connector portion 24 is provided on a flat surface portion, and a rewritable display portion 22 is formed on the same flat surface portion.

Further, a recording medium having no direct electrical contact (connector), such as a memory card 30 shown in (c), is also assumed (for example, a magnetic card). The recording medium 40 shown in (d) has a cylindrical shape and cannot be called a "card", but can be used as a removable medium.

In the following description, the memory card 10 shown in (a) will be described as an example. However, the specific form of the removable medium is not limited to this, and the present invention is applied to (b) to (d). ) Can be similarly applied to various recording media. Also, the rewritable display units 12, 22, 32, and 42 need only be provided in a portion that is easy to see in appearance and does not hinder the data read / write process, and is a place where the display unit is provided on the outer surface of the medium. Is not particularly limited.

The rewritable display unit 12 is made of, for example, a device using a polymer nematic liquid crystal. Regarding "display means using polymer nematic liquid crystal",
The detailed contents are disclosed in Japanese Patent No. 2936567. Referring to the publication, the principle is outlined in FIG.
As shown in (a), the polymer liquid crystal film 50 is configured as an adhesive film having a visible information display section 52 mainly composed of a polymer nematic liquid crystal. That is, the photothermal reflection layer 55 is formed on the substrate 54, the visible information display section 52 is laminated thereon, and the uppermost layer is the transparent protective layer 57. Further, an adhesive layer 58 is provided on the back surface of the substrate 54, and as shown in FIG.
0 is attached to the memory card 10. When the flatness of the card surface is impaired by the attachment of the polymer liquid crystal film 50, it is preferable to form the recess 10A on the card side.

By heating the polymer liquid crystal film 50 using a heater (such as a thermal head), various information such as characters and symbols can be written / erased by the phase transition behavior of the polymer nematic liquid crystal.

FIGS. 3 to 6 show examples of the remaining capacity display on the rewritable display unit 12. FIG. FIG.
This is an example in which the remaining capacity is displayed using only character information. Frame 6
0 indicates the display content on the display unit 12, and the frame 6
“256 MB” shown below 0 (outside the frame) is obtained by printing (or pasting a label) information on the capacity of the entire card on the card surface. Since the capacity of the entire card is fixed information that does not change and does not need to be rewritten,
Non-rewritable display such as printing is possible. Of course, a similar display may be performed on the rewritable display unit 12.

The display shown in FIG. 3 shows that the memory card 10 having a total capacity of 256 MB is currently used up to 128 MB, and the memory card 10 is mounted on a digital camera and the number of pixels is “2048 × 3072”. ”And recording quality (compression rate)“ Fine ”
This indicates that shooting for 32 frames is possible.

Information on the currently used capacity (128 MB
"Use") may be displayed (indicated) indirectly by displaying the remaining capacity on the display unit 12, or the numerical value of the remaining capacity may be directly displayed instead of or in addition to the display of the used capacity. May be. When the memory card 10 is used in a digital camera, the display of the number of recordable images is considered to be effective. However, when the same memory card 10 is used in a device other than the camera such as an audio player, the number of recordable images is Since the display is unnecessary, the display of the number of shootable images is not an essential display item.

FIG. 4 is an example showing the remaining capacity using a bar graph 62. Here, the display is performed using both the bar graph 62 and the characters (“128 MB remaining”), but the characters may be omitted and only the bar graph may be used.

FIG. 5 shows the used capacity and the remaining capacity using a pie chart 64. In the figure, character information ("Use 2
5% "and" 75% remaining ") are used together, but the characters may be omitted and only the pie chart 64 may be used. In FIG. 6, in order to make the display form of FIG. 5 easier to see, a difference (a difference in radius) between a circle graph portion indicating the used capacity and a circle graph portion indicating the remaining capacity is provided. As shown in FIG.
The radius r2 of the pie chart portion 66 indicating the used capacity is smaller than the radius r1 of the pie chart portion 65 indicating the remaining capacity (r2
By adopting the display mode <r1), the quantitative relationship between the used capacity and the remaining capacity can be grasped at a glance (intuitively).

FIG. 7 is an external view of a digital camera using the memory card 10 described above. A photographing lens 72, a finder window 74, and an auxiliary light emitting unit (strobe) 76 are provided on the front of the camera 70, and a shutter button 78 and a power switch 80 are provided on the top of the camera. Also, on the camera side opposite to the grip 82,
A card slot (media insertion portion) 84 for mounting the memory card 10 and an eject button 86 are provided.

As the photographing lens 72, a lens having a variable focal length such as a zoom lens or a single focus lens may be used. An imaging device such as a CCD image sensor (not shown in FIG. 7, described as 102 in FIG. 9) is disposed behind the taking lens 72. The shutter button 78 is of a two-stage type, and when the shutter button 78 is lightly pressed and stopped “half-pressed”, automatic focusing (AF) and automatic exposure control (AE) operate to activate AF and A.
Lock E and push further from "half-press""full-press"
The shooting is performed in the state of.

The power switch 80 is also used as a mode change switch, and has an "OFF position" at which the power is turned off,
"Shooting ON position" which is turned on in still image shooting mode,
And the "reproduction ON position" which is turned on in the reproduction mode.
The position can be switched. Instead of the power switch (hereinafter, referred to as a power / mode switch) 80 as in this example, a power switch for only power ON / OFF and a mode switching means such as a mode dial for switching between a still image shooting mode and a reproduction mode. May be provided.

FIG. 8 is a rear view of the camera 70. On the back of the camera 70, a viewfinder 88, an image monitor 90, a zoom switch 92, a multifunctional cross button 9
4, a menu key 95, an execution key 96, and a cancel key 97 are provided. The image monitor 90 is, for example,
It is composed of a liquid crystal display (LCD) and can be used as an electronic viewfinder for checking the angle of view during shooting.
This is display means capable of displaying a preview image of a captured image, a reproduced image read from the memory card 10, and the like. Selection of menus using the cross button 94 and setting of various items in each menu are also performed using the display screen of the image monitor 90.

The zoom switch 92 is composed of a lever switch which can be operated in the up-down direction. The switch is operated in the upward direction to perform a zoom movement in the telephoto (TELE) direction, and is operated in the downward direction to perform the wide-angle (WIDE) operation. ) Zoom in the direction. The cross button 94 is pressed in one of four directions (up, down, left,
The right button allows the user to input instructions, and is used as an operation button to select various setting items on the menu screen or to change the settings, and to adjust the electronic zoom magnification and to forward / return the playback frame. It is used as an instruction means.

The menu key 95 is used to make a transition from the normal screen of each mode to the menu screen. The execution key 96 is used, for example, for confirming the selected contents and instructing execution (confirmation) of processing. The cancel key 97 is used to cancel (cancel) an item selected from the menu or to return to the previous operation state.

The photographer operates the zoom switch 92 to determine the angle of view while checking the real-time image (through image) displayed on the viewfinder 88 or the image monitor 90, and performs photographing by pressing the shutter button 78. .

FIG. 9 is a block diagram showing the internal configuration of the camera 70. The light that has passed through the taking lens 72 and the shutter / aperture mechanism 100 forms an image on the imaging device 102. The mechanical shutter prevents light from being incident on the imaging device 102 and causing smear when a signal is read from the imaging device 102, but is not always necessary depending on the configuration of the imaging device 102. As the aperture mechanism, a single aperture mechanism or a mechanism capable of switching a plurality of apertures can be applied. The strobe light 74 used as auxiliary light at low illuminance or the like can be forced when required or required. The strobe 74 is not limited to a strobe device using a xenon tube, and may be configured by a white LED, a lamp, or the like.

The driving circuit 104 includes a timing generation circuit and an imaging device driver, and the imaging device 102
Is driven by the imaging device driver at the timing generated by the timing generation circuit, and outputs an image signal. The drive circuit 106 is a block including a drive circuit for the photographing lens 72, the shutter / aperture mechanism 100, and the strobe 74 in addition to the above. The imaging device driver may not be required depending on the driving voltage conditions of the imaging device 102.

The image signal output from the image pickup device 102 undergoes analog signal processing such as color separation and gain adjustment in an analog signal processing circuit 106, and then an A / D converter 108.
Is converted into a digital signal. The digitized image signal is sent to a digital signal processing circuit 110, where it undergoes digital signal processing such as luminance / color difference signal (YC) conversion and gamma correction.

Image data that has undergone predetermined digital signal processing is temporarily recorded in the memory 112. Image monitor 9
To display an image at 0, the contents of the memory 112 are read and sent to the image monitor 90. Thus, an image can be displayed on the image monitor 90. In addition, the image data after photographing captured in response to a recording instruction (for example, full depression of the shutter button 78) is compressed by the compression / expansion circuit 114 and then recorded on the memory card 10. Note that, depending on the photographing mode, the recording may be performed without the compression process (without compression).

In this embodiment, the memory card 10 described with reference to FIG. 1 is used as means for storing image data.
The means for storing the image file is not limited to a removable medium detachable from the camera body, but may be a recording medium (built-in memory) built in the camera 70.

In the reproduction mode, image data is read from the built-in memory or the memory card 10, and the read image data is subjected to expansion processing by a compression / expansion circuit 114 as necessary. Monitor 3
6 is output.

The entire camera is controlled by the CPU 120. That is, the CPU 120 controls the shutter button 7
Based on an input signal from a shutter switch 122 and other operation switches 124 that are linked to the control unit 8, the overall control of each circuit of the camera is performed.

The camera 70 of the present embodiment corresponding to the memory card 10 capable of displaying the remaining capacity has a print head (thermal head) 126 as means for rewriting the remaining capacity display of the memory card 10. In order to perform the rewriting process of the remaining capacity display at the time of card ejection, a power ejection method is adopted, and the camera 70 includes an ejection motor 128 serving as a power source for card ejection. A drive circuit 130 for driving the print head 126 and the ejection motor 128
Controlled by 0.

FIGS. 10A and 10B are diagrams showing the construction of the writing mechanism for displaying the remaining capacity, wherein FIG. 10A is a view as seen from the card ejection direction, and FIG. 10B is a view as seen from the side. As shown in these drawings, a pair of rollers 132 and 133 are disposed to face each other with the memory card 10 interposed therebetween, and the rollers 132 and 133 rotate around shafts 134 and 135. One of the pair of rollers 132 and 133 (the upper roller 132 in FIG. 10A)
Is driven to rotate by the rotational force of the ejection motor 128. The ejection motor 128 is also used as a power source for the pull-in operation when the card is inserted as well as when the card is ejected.

In FIG. 10B, the memory card 10
A print head 126 acting on the rewritable display unit 12 of the memory card 10 is disposed above the memory card 10. The print head 126 functions as a write head and also functions as an erase head.

The memory card 10 is held between the rollers 132 and 133, and the roller 132 is rotated by driving the ejection motor 128, whereby the memory card 10 is drawn into or ejected from the camera body. In response to the operation of the eject button 86 described in FIG. 7, the ejection motor 128 is rotated to eject the memory card 10,
By controlling the heating of the print head 126, the display contents of the rewritable display unit 12 are rewritten.

In FIG. 10, one print head 126
Although the mechanism for sharing the erasing head and the writing head for erasing the recorded contents has been described, a configuration in which the erasing head and the writing head are separately provided is also possible.

When the memory card 10 is inserted into the card slot 84 of the camera 70, the insertion of the memory card 10 is detected by using a media detecting mechanism as shown in FIG. That is, the push-open type door 140 is installed in the opening of the card slot 84,
A door detection switch 142 that can be switched ON / OFF by opening and closing 0 is provided at a predetermined position near the door.

Before the medium is inserted, as shown in FIG. 11A, the door 140 is urged to a closed state by a spring (not shown). From this state, the door 140 is pushed by the insertion operation of the memory card 10, and the door 140 is
4. As shown in FIG.
When the door 40 is opened by the opening operation of the door detection switch 1
42, and the open state of the door 140 (that is, the medium insertion state) is detected. When the memory card 10 is removed from the card slot 84, the door 140 returns to the state shown in FIG. 11A by the urging force of a spring (not shown).

When it is detected that a part of the memory card 10 has been inserted into the card slot 84, the motor 128 described with reference to FIG. 10 is operated to rotate the rollers 132 and 133, and the memory card 10 is pulled into the camera body. Although not shown in the drawing, a detection switch for detecting the mounted state of the memory card 10 is also provided in the connector portion on the card slot 84 side, and when the memory card 10 is properly inserted (when the memory card 10 is correctly connected). In step ()), the motor 128 used for the pull-in operation is stopped. Alternatively, instead of the detection switch, the electrical contact (connection state) is detected by the connector on the card slot 84 side, and the motor 128 is detected.
May be stopped.

At this time, the print head (recording / erasing head) 126 is set to the erasing mode, and erases the entire recording area of the display section 12 (all the written contents). Note that the insertion speed of the memory card 10 is controlled to an optimum speed for erasing. Then, the print head 126 is set to the write mode while the memory card 10 is ejected by the motor 128 by the eject operation,
The remaining capacity display on the display unit 12 is updated.

Here, an example in which the electric ejection (power ejection) is used is shown, but an embodiment in which the manual ejection mechanism mechanically ejects the memory card 10 by an operation force of a manual operation is also possible.

When a manual ejection mechanism is employed, it is necessary to select a material whose writing speed does not significantly affect print quality. The operation at the time of card insertion is the same as that described above, except that the motor 128 does not contribute to the insertion operation. The print surface of the display unit 12 is erased by the print head (recording / erasing head) 126 while the memory card 10 is pushed in by hand. However, in order to perform optimum erasing, it is preferable to install a rotary encoder instead of the motor 128 shown in FIG. 10 and detect the insertion speed. Of course, this speed detection is also used for printing under optimum conditions even at the time of ejection.

Next, the operation of the camera 70 configured as described above will be described. FIG. 12 is a flowchart illustrating an example of a sequence for writing remaining capacity information to the display unit 12 of the memory card 10 in the camera 70.

When the photographing mode starts, the CPU 12
0 performs reading processing of the photographing setting information (step S
210). In this process, various setting information such as the number of recording pixels and the compression ratio is read. Thereafter, it is determined whether or not an image can be recorded on the memory card 10 (Step S).
212). It is determined that recording is not possible, for example, when the memory card 10 is not mounted, when the free space of the memory card 10 is insufficient, or when the memory card 10 is “write-protected” (write-protected). In this case, the flow branches to step S214 to perform “error processing”. In this “error processing”, for example, the image monitor 90
A warning message is displayed at the top to urge the operator to exchange media.

If it is determined in step S212 that recording is possible, the flow advances to step S216 to wait for the shutter button 78 to be pressed. Step S216
When it is detected that the shutter button 78 has been pressed in (2), a photographing process is performed (step S218), and a recording operation of writing the captured image to the memory card 10 is performed.

Next, it is determined whether or not the recording process has been completed (step S220). After confirming that the recording process has been completed, the remaining capacity of the memory card 10 is calculated (step S222). Then, a process of recording the information on the calculated remaining capacity on the display unit 12 of the memory card 10 is performed (step S224). After step S224, the process returns to step S212, and the above-described processing is repeated.

FIG. 12 shows an example of the sequence in the photographing mode. However, also in the reproduction mode, the remaining capacity of the memory card 10 changes due to file deletion, reformatting, and the like. Therefore, in the reproduction mode, when a file is deleted or reformatted, the remaining capacity of the memory card 10 is calculated and the information is recorded on the display unit 12 of the memory card 10.

It is important to display the remaining capacity of the memory card 10 after the memory card 10 has been taken out (pulled out) from the device.
Alternatively, it is not always necessary to update the display on the display unit 12 by calculating the remaining capacity each time one image is erased. That is, it is more efficient to collectively calculate the remaining capacity at the time of ejection and write the information.

FIG. 13 shows a sequence example when the remaining capacity is written at the time of ejection. When the remaining capacity writing sequence starts, first, it is determined whether or not the eject button 86 has been pressed (step S310). When the eject button 86 is pressed (when YES is determined), the remaining capacity of the memory card 10 is calculated (step S312), and the remaining capacity recording process is executed (step S314).

After recording information on the display unit 12,
After executing the memory card eject operation (step S316), the power supply is turned off (step S31).
6). Thus, the remaining capacity write sequence ends.

Here, the power eject is assumed, but when the power is not ejected, the state of the switch not linked to the eject button 86 but linked to the opening and closing of the recording medium cover (cover covering the opening of the card slot) is determined. As a material, the remaining capacity may be calculated immediately after the recording medium cover is opened, and the information may be written to the display unit 12.

Note that the sequence shown in FIG. 13 is not limited to the digital camera as in the present embodiment, but may be applied to other devices using a recording medium, such as an audio player, a personal digital assistant (PDA), and a personal computer. Applicable to

By using the method described above, the memory card 10 itself is made compatible with the conventional memory card, and the newly rewritable display unit 12 is added, so that the remaining capacity can be grasped at a glance. .

However, it is conceivable that the conventional device having no writing function for the display unit 12 handles the memory card 10 having the rewritable display unit 12. In this case, since the display unit 12 is not updated, a situation in which the display content of the display unit 12 does not match the actual remaining capacity may be assumed.

Therefore, when writing or erasing data in the memory card 10, a line to be accessed is always detected (in the case of a serial communication system, a write or erase command is detected). When data is written or erased, the display on the display unit 12 may be invalidated.

As means for this, the memory card 10
Is provided with an area in which the memory card 10 can be rewritten alone. When data is written to or erased from the memory card 10, the information content is updated in the independently rewritable display portion (hereinafter referred to as “self-rewriting display portion”). May be displayed.

FIG. 14 shows a configuration example of the memory card 10 to which the self-rewriting display unit 150 is added. Near the self-rewriting display section 150, a description is printed, "If this part is white, the remaining amount display is invalid."

FIG. 15 is a sectional view showing the structure of the self-rewriting display unit 150. As shown in the figure, the self-rewritable display section 150 has a display layer 1 mainly composed of a polymer nematic liquid crystal.
52, a reflector 154, and a mesh heater 156. FIG. 16 is a block diagram of the memory card 10 to which the self-rewriting display unit 150 is added. This memory card 10 has a memory 16 for storing digital data.
0, a memory controller 162, an interface unit 164 that exchanges data with devices, and a heater 15
8 and a heater control unit 166. The memory controller 162 is provided with a write determination unit 168,
In the write judging section 168, the self rewriting display section 1
It is determined whether or not the display content of 50 is to be rewritten. That is, the write determination unit 168 determines whether data has been written or erased in the memory 160 when accessed, and gives a command to the heater control unit 166 according to whether or not the data has been rewritten.

The heater control unit 166 includes
The operation of the heater 156 is controlled in accordance with the command from the controller 68 to perform heating control for making the polymer nematic liquid crystal opaque or transparent. With this structure, the self-rewriting display unit 150 can be rewritten by the memory card 10 alone.

When it is determined that the data in the memory 160 has been rewritten, the self-rewriting display unit 150 is made cloudy. In the case of a device having a rewriting function of the display unit 12,
When the display on the display unit 12 is updated, the display on the self-rewriting display unit 150 is deleted, and then information on the remaining capacity is newly recorded.
If the device does not have the rewriting function of the display unit 12, the memory card 10 is taken out while the self-rewriting display unit 150 is cloudy, and the display unit 12 is invalid (the remaining capacity display on the display unit 12). And the actual remaining capacity do not match).

In FIG. 10, the rewriting process of the rewritable display unit 12 is performed by the device in which the memory card 10 is used. However, the technique of the self-rewriting display unit 150 described with reference to FIG. 15 is applied. Alternatively, the memory card 10 may have a function of calculating the remaining capacity and displaying the calculated remaining capacity on the display unit 12.

FIGS. 17 and 18 show an embodiment thereof.
As shown in FIG. 17, a rewritable display unit 172 is provided on the surface of the memory card 170, and information “256 MB” indicating the entire capacity of the card is printed outside the frame 174. Reference numeral 176 is a connector unit. As shown in the block diagram of FIG. 18, the memory card 170 includes a memory 178 for storing digital data, a memory controller 180, an interface unit 182, a display unit 172,
And a display control unit 184.

The memory controller 180 has the memory 17
8 (hereinafter referred to as “remaining capacity calculating unit”) 186, and a command is given to the display control unit 184 based on the calculation result of the remaining capacity calculating unit 186. The display control unit 184 performs control of rewriting the display content of the display unit 172 according to a command from the remaining capacity calculation unit 186. As described with reference to FIG. 2, it is desirable that the display unit 172 does not consume power except for rewriting (including erasing), such as a ferroelectric liquid crystal display.

As described above, according to the embodiment of the present invention, the remaining capacity of the memory card 10 used in the camera 70 or the like can be known without accessing the memory card 10. By recording the last access date and time in addition to the remaining capacity, it is possible to know when the data was last used, which may be a trigger for noticing that "backup must be performed".

The rewritable display sections 12 and 172
It is also preferable to display the name of the device used last and the action (operation details) together with the remaining capacity as the information to be displayed. That is, when a picture is taken by the camera 70 and the camera 70 is placed in a dedicated cradle (stationary docking station), a picture taken in the memory card 10 is automatically taken into a device such as a personal computer (PC). When the memory card 10 is used at the time of shooting, the memory card 10
Is displayed to indicate that the last action is shooting. After that, it is placed in the cradle, the image data is transferred to the personal computer, and after the backup is taken, the display content may be rewritten as “backed up” or “PC transferred”. Good.

By doing so, it is possible to easily grasp whether or not the memory card 10 has been backed up just by looking at the memory card 10. For example, if you have multiple memory cards and the memory card currently in use becomes full and there is no other new memory card to use next, Instantly determine whether the contents of the memory card can be erased.

In the above description, a digital camera has been described as an example.
It can be implemented similarly. For example, the present invention is applied to all devices using removable media, such as mobile phones, personal digital assistants (PDAs), personal computers (PCs), household appliances (microwave ovens, refrigerators, VCRs, etc.), clocks, car navigation devices, and the like. Can be applied.

Next, an embodiment of a PC card reader will be described. Basically, the camera 7 described with reference to FIGS.
0, and a similar mechanism can be used. Of course, it can be realized not only by power ejection but also by manual ejection.

FIG. 19 is a block diagram showing a PC card reader according to the embodiment of the present invention. PC card reader 190
Is mainly a memory controller / interface controller (hereinafter abbreviated as “controller”) 1
92, a print head 194, an ejection motor 196, and a drive circuit 198. The PC card reader 190 is connected to a personal computer (PC) 400 and other external devices through a predetermined interface. In addition, USB, IEEE1394,
There are various modes such as SCSI, IEEE 1284, and a dedicated bus.

The PC card reader 190 does not have an intelligent CPU.
It is controlled by 0 or the like.

The drive circuit 198 drives the print head 194 and the ejection motor 196 according to a command from the controller 192. The detecting means when the memory card 10 is inserted into the PC card reader 190 is shown in FIG.
The same means as the example described in 1 can be applied. The variation of the configuration of whether to pull in the memory card 10 using the power of the motor 196 at the time of insertion or to insert the memory card 10 only with a manual operation force is the same as that of the camera 70 described above. When the memory card 10 is inserted into the PC card reader 190, the display unit 12 is
Is erased, and information on the remaining capacity is written when ejected.

Next, still another example of the present invention will be described.

In the above description, a memory card is exemplified as a recording medium. However, the scope of the present invention is not limited to this, and the present invention can be similarly applied to other recording media. For example, CD-R, CD-RW, DVD-RA
M, DVD-RW, floppy (registered trademark) disk,
The present invention is also applicable to a recording medium such as an MO disk. In these recording media, it is not possible to instantaneously judge how much the recording area remains just by appearance. When the present invention is applied to these disc-type media, whether the media is unused and immediately usable,
It is very convenient because it is easy to determine whether the device is being used halfway.

In the case of a medium having a jacket, such as a DVD-RAM, MO disk, or floppy disk, a display area may be provided on the surface of the jacket, and the remaining capacity may be displayed there. FIG. 20 shows an example of an MO disk. In the case of the MO disk 420, the place where the rewritable display portion is formed includes the label portion of the jacket 422 (reference numeral 424) and the vicinity of the shutter 426 (reference numeral 4).
28) or a part of the shutter 426 (reference numeral 430).

A drive using a medium with a jacket often has a power eject. Therefore, the operation of rewriting the display contents at the time of the eject can be performed in the same manner as the camera 70 described above.

In the case of a disk-shaped recording medium such as the CD-R 440 shown in FIG. 21, it is preferable to provide a rewritable display portion for displaying the remaining capacity at the peripheral portion (444) of the center hole 442.

Further, according to the present invention, as shown in FIG.
The present invention is also applicable to a C card type personal digital assistant (PDA). The PDA 450 is a PC card type PDA compatible with a PCMCIA slot, and has a liquid crystal display unit 452, operation buttons 454 to 457, and a display unit for displaying remaining memory capacity (hereinafter referred to as a remaining capacity display unit) on a flat surface. 46
0, and a touch panel is provided on the screen of the liquid crystal display portion 452. Further, a connector 462 for exchanging data with a personal computer or other devices is provided on the left end surface of the PDA 450 in FIG.

The PDA 450 has a schedule management function,
Equipped with multiple functions such as an address book function, dictionary function, memo pad function, and calculator function, this unit can be used alone as a mobile electronic tool. The PDA 450 can be connected to a device such as a personal computer, and can read and write data using the personal computer. In this regard, this PDA 450 can also be treated as a type of removable media.

The home button 454 is an operation button for instructing ON / OFF of the power and movement to the basic screen (home screen). The cancel button 455 is an operation button for issuing a command to return to the previous screen or a command to cancel the operation. An enter button 456 is a button for determining a selection. The up / down cursor button 457 is used for moving the cursor up / down and selecting an item. In the lowermost column of the liquid crystal screen, a calendar function, an address book function and other various function call keys 464 are arranged.

The remaining capacity display section 460 is composed of a display section mainly composed of a polymer nematic liquid crystal as described with reference to FIG. 2. When the power of the PDA 450 is turned off, the remaining capacity display is maintained. It has become something.

In the above-described embodiment, an example is described in which a polymer nematic liquid crystal is used as a rewritable display unit for displaying a remaining capacity. However, the configuration of the display unit is not limited to this. Hereinafter, a modified example will be described.

<Pressure ink system> JP-A-2000-187
It is also possible to configure the display unit of the remaining capacity by utilizing the technology of the reusable electric paper disclosed in JP-A-253-253. Referring to the publication, the structure of the electric paper is outlined. As shown in FIG. 23, the sheet of the electric paper 470 is composed of a matrix of independent print cells 472, and the resolution of the paper is defined by the print cells 472. You.

FIG. 24 is a sectional view of the print cell 472. Electric paper 470 has a seven-layer structure,
The bottom layer is the bottom substrate 480, on which the first intermediate layer 4
82 forms the side wall of the lower reservoir 486 that holds ferrofluidic coloring fluid (colored fluid containing magnetic particles) 484 such as ferrofluidic ink. The second intermediate layer 488 forms the top layer of the lower reservoir 486, and the third intermediate layer 490 defines the thickness of the passage 462. Fourth intermediate layer 494 defines the bottom of opaque (visible) upper reservoir 496 and fifth intermediate layer 498 defines the sidewalls of upper reservoir 496. Reference numeral 500 of the uppermost layer is a top transparent cover layer. Bottom substrate 48
0 is opaque (for example, white), and the intermediate layers 482 and 48
8, 490, 494 are similarly opaque white. The ferrofluid coloring fluid 484 has a color (for example, black) that can be distinguished from the color (white) of the intermediate layer.

When an appropriate magnetic force is applied in the direction perpendicular to the plane of the electric paper 470, the ferrofluid coloring fluid 484 moves between the upper reservoir 496 and the lower reservoir 486 via the passage 492. As shown in FIG. 24, when ferrofluidic coloring fluid 484 is present in lower reservoir 486, print cell 472 appears to be the color of the intermediate layer (white). Also, as shown in FIG. 25, the ferrofluid coloring fluid 484 is connected to the upper reservoir 49.
When moved to 6, print cell 472 appears to be the color of ferrofluid coloring fluid 484 (black).

The bar array 502 of addressable magnetic elements shown in FIG.
Can be colored, and the display content can be erased by moving the ferrofluid coloring fluid 484 to the lower reservoir 486 for all cells.

It is possible to adopt a mode in which the electric paper 470 is attached to a recording medium to form a display unit for displaying the remaining amount.

<Liquid Crystal System> It is also possible to use a technique of a liquid crystal display device disclosed in Japanese Patent No. 2930169 to form a display unit of the remaining capacity. Referring to FIG. 26, the structure of the liquid crystal display device is schematically described with reference to the publication. Mixed across directions. Liquid crystal of the first kind 5
16 is a dielectric anisotropy Δε> 0, a refractive index anisotropy Δn> 0
Is a liquid crystal (liquid crystal I) showing
It is enclosed in. The second type of liquid crystal 518 is composed of a liquid crystal (liquid crystal II) exhibiting a dielectric anisotropy Δε <0 and a refractive index anisotropy Δn> 0. The second type of liquid crystal 518
May be a liquid crystal (liquid crystal III) exhibiting a dielectric anisotropy Δε> 0 and a refractive index anisotropy Δn <0.

By combining the two types of liquid crystal materials, the difference in the apparent refractive index of the liquid crystal in the ON / OFF state of the electric field increases. As a result, the electro-optical characteristics are agile,
In addition, a liquid crystal display device using a light dispersion mode with excellent contrast can be achieved. With this technology, a power-saving direct-view display that does not require a backlight can be realized.

<Electrostatic System> It is also possible to use an electric paper disclosed in Japanese Patent Application Laid-Open No. H11-316973 to form a display unit for the remaining capacity. The structure of Gyricon electric paper is outlined with the aid of this publication. FIG. 27 is a perspective view of a gyricon sheet 600, and FIG. 28 is a sectional view of a main part. As shown in these figures, the Gyricon sheet 60
0 indicates that the plurality of two-color rotating elements 610 are
2, the holding medium 612 has a structure sandwiched between a first capsule layer 614 and a second capsule layer 616.

The spherical two-color rotating element 610 is half-color-coded by two colors (for example, white and black) with a clear contrast, and has an electric dipole orthogonal to the plane separating the two halves. Each element is in a liquid-filled cavity 621 in which a positive mobile ion space charge 640 and a negative mobile ion space charge 642 are located.
And there is.

The first encapsulation layer 614 is patterned with conductive charge retaining islands 618. The charge storage islands 618 are arranged in a simple two-dimensional (x-y) matrix with a square shape around the circumference, and are separated by narrow insulating channels 619 between the islands.

The second encapsulation layer 616 is formed of the conductive coating 62.
0 is applied and this second capsule layer is electrically grounded. The external charge transfer device 680 connected to the power supply 670 moves across the sheet in the direction D in FIG. Power supply 67
0 can create the required voltage to rotate the two-color rotating element 610, and the movement of the charge 682 to the charge-retaining island 618 by the external charge transfer device 680 causes the two-color rotating element present in the electric field formed thereby. 610 rotates, and either white or black faces upward depending on the direction of the electric field. External charge transfer device 68
Even when 0 is retracted from the charge holding island 618, the state of the two-color rotating element 610 continues to be held by the electric field due to the charge 682 held in the island.

<Magnetic System> It is also possible to adopt a mode in which a principle similar to the above-mentioned electrostatic system is implemented by a magnetic system. FIG. 29 shows the principle diagram. The space between the transparent cover 700 and the base 710 is filled with a transparent gel 720, and a plurality of two-color rotating elements 740 are held in a layer of the transparent gel 720. The spherical two-color rotation element 740 is half-color-coded in two colors (for example, white and black) with a clear contrast,
A magnet 742 having an N pole and an S pole in a direction perpendicular to the plane separating the two halves is incorporated. Note that, instead of the magnet 742, the two-color rotating element 742 itself may be configured by a magnetized sphere.

The base 710 has a two-color rotating element 7.
Fixing metal (for example, iron) 7 for restricting 40 to a predetermined position
44 are provided. The two-color rotating element 740 is attracted and fixed to the fixing metal 744 by the action of the magnet 742.

At the time of writing, as shown in FIG. 30A, a two-color rotating element 740 is rotated by a magnetic field using a magnetic head 750. As a result, FIG.
As shown in (b), the black portion is located on the upper side and looks black when viewed from above. Even when the magnetic head 750 is retracted, the state of the two-color rotating element 740 (that is, the display content) is maintained because the fixing metal 744 and the two-color rotating element 740 are attracted.

[0107]

As described above, according to the present invention, a rewritable display is provided on the outer surface of a recording medium, and information indicating the remaining capacity of the recording medium is displayed on the display. Thus, even when the recording medium is removed from the device, the remaining capacity can be grasped by the medium alone.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a recording medium according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a structure of a polymer liquid crystal film applied to a rewritable display unit.

FIG. 3 is a diagram showing an example of a remaining amount display on a rewritable display unit.

FIG. 4 is a diagram showing an example of a remaining amount display on a rewritable display unit.

FIG. 5 is a diagram showing an example of a remaining amount display on a rewritable display unit.

FIG. 6 is a diagram showing an example of a remaining amount display on the rewritable display unit.

FIG. 7 is an external view of a digital camera using the recording medium of the present invention.

8 is a rear view of the camera shown in FIG. 7;

FIG. 9 is a block diagram showing the internal configuration of the camera.

FIG. 10 is a configuration diagram of a writing mechanism for displaying a remaining capacity;
(A) is a view from the card ejection direction, and (b) is a view from the side.

11A and 11B are structural diagrams of a medium detection mechanism, wherein FIG. 11A shows a state before a medium is inserted, and FIG. 11B shows a state when a medium is inserted.

FIG. 12 is a flowchart showing an example of a sequence for writing the remaining capacity to the display unit of the memory card in the camera of the present example.

FIG. 13 is a flowchart showing a sequence example when writing remaining capacity at the time of ejection;

FIG. 14 is a diagram illustrating a configuration example of a memory card to which a self-rewriting display unit is added;

FIG. 15 is a sectional view showing the structure of a self-rewriting display unit.

FIG. 16 is a block diagram of a memory card to which a self-rewriting display unit is added.

FIG. 17 is a diagram showing an example of a memory card having a function of calculating a remaining capacity.

18 is a block diagram of the memory card shown in FIG.

FIG. 19 is a block diagram of a PC card reader according to the embodiment of the present invention.

FIG. 20 is a perspective view of an MO disk to which the present invention is applied.

FIG. 21 is a plan view of a CD-R to which the present invention is applied.

FIG. 22 is a perspective view of a PC card type portable information terminal to which the present invention is applied.

FIG. 23 is a perspective view of an electric paper applicable to the rewritable display unit.

24 is a sectional view of a print cell of the electric paper shown in FIG.

FIG. 25 is a sectional view of a print cell of the electric paper shown in FIG. 23;

FIG. 26 is a sectional view of a liquid crystal display device applicable to a rewritable display portion.

FIG. 27 is a perspective view of a gyricon sheet applicable to a rewritable display unit.

FIG. 28 is a side view of the gircon sheet shown in FIG. 27;

FIG. 29 is a sectional view showing the structure of a magnetic display sheet applicable to the rewritable display unit.

30 is an essential part cross sectional view showing the operation principle of the display sheet shown in FIG. 29.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Memory card (recording media), 12 ... Display part (rewritable display part), 14 ... Connector part, 50 ...
Polymer liquid crystal film, 62: bar graph, 64: pie graph, 70: camera (electronic device), 84: card slot (media insertion part), 86: eject button, 90:
Image monitor, 102: imaging device, 120: CPU
(Control means, memory management means), 126: print head (display rewriting means), 128: ejection motor, 1
50: self-rewriting display area (self-rewritable area), 166 ...
Heater control unit (display control unit), 168: writing determination unit (determination unit), 184: display control unit, 186: remaining capacity calculation unit (calculation unit), 190: PC card reader (electronic device), 400: personal computer ( Electronics)

Claims (7)

[Claims] 1. A recording medium, wherein a rewritable display unit is provided on an outer surface of the recording medium, and information indicating a remaining capacity of the recording medium is displayed on the display unit. 2. The display unit according to claim 1, wherein the display content is rewritten by an electronic device using the recording medium, and the display of the remaining capacity is maintained in a state where the recording medium is removed from the electronic device. Claim 1.
Recording media according to. 3. The recording medium has a self-rewritable area rewritable by the recording medium itself in a part of the rewritable display unit, and determines whether data stored in the recording medium has been rewritten. And a display control means for displaying, in the self-rewritable area, information indicating that the recorded content has been rewritten, when the judgment means obtains a judgment that rewriting has been performed. 3. The recording medium according to claim 1, wherein: 4. The recording medium includes: calculating means for calculating a remaining capacity; and display control means for changing a display of the remaining capacity on the display unit based on a calculation result of the calculating means. The recording medium according to claim 1 or 2, wherein 5. An electronic device using the recording medium according to claim 1, wherein the recording medium is inserted into the recording medium, and the recording medium is inserted into the recording medium. Media reading means for reading and writing media; memory management means for grasping the remaining capacity of the recording medium; and display rewriting means for rewriting the display of the remaining capacity on the display unit according to the memory management means. Electronic equipment. 6. The electronic device has a control unit, and the control unit causes the display rewriting unit to rewrite the display of the remaining capacity every time data is written or erased by the media reading unit. The electronic device according to claim 5, wherein the electronic device controls display rewriting means. 7. The electronic apparatus has an ejecting unit for ejecting a recording medium from the medium insertion unit, and a control unit, wherein the control unit is configured to, when the recording medium is ejected by the ejecting unit, eject the recording medium. 6. The electronic device according to claim 5, wherein the display rewriting means controls the display rewriting means to rewrite the display of the remaining capacity.