JPH01288491A - Ic card - Google Patents

Abstract

PURPOSE:To enable indication and holding of residual memory of an IC card to be performed without incorporating a battery, by providing a special indicating section to the card so that information including those stored in a memory section can be indicated. CONSTITUTION:Residual memory capacity of a memory 3 is detected through a CPU 6 which provides a command signal based on detected information to an indicating section 4 where the residual memory is displayed digitally or in bar graph. At this time, writing into the indicating section 4 is carried out with the source voltage of a camera 5. When residual memory data are written into the indicating section 4 and indicated thereon, voltage supply from the camera 5 is stopped. The indicating section employs any one of ferro-dielectric liquid crystal, photochromic device, electrochromic device, cataphoretic display element or magnetic pattern display element. Since the residual memory capacity data are displayed on a card body 1, storable image data can be checked instantaneously. The data are held as it is even upon interruption of power source.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an IC card that is used by being attached to an external device such as a still video camera, and stores information from the external device in a storage unit of a semiconductor integrated circuit or the like. In particular, the present invention relates to an IC card having a function of displaying information regarding the storage capacity of a storage unit, etc.

[Conventional technology]

In general, this type of IC card has a memory section such as a semiconductor integrated circuit mounted on an insulated plastic substrate, such as a device that stores image data obtained by capturing an image with a still video camera, etc., in an IC card mounted in the camera. It is buried inside.

One example of such an IC card is Japanese Patent Laid-Open No. 62-
As shown in Japanese Patent No. 50983, there is a device that is provided with a display section for easily checking how much storage capacity is currently left in the storage section. A liquid crystal display section is normally used as this display section, but this liquid crystal display section needs to be supplied with power from a battery provided within the card.

[Problem to be solved by the invention]

IC cards have size limitations. Therefore, in order to provide an IC card with various functions, it is necessary to incorporate a large number of elements into a limited space. For this reason, there is a desire to avoid incorporating a power supply unit such as a battery as much as possible.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to be able to display the total remaining storage capacity of the storage unit and stably maintain that state without having to incorporate a batch memory into the IC card, and to use an external device to display the remaining capacity of the storage unit. To provide an IC card whose contents can be freely rewritten.

[Means to solve the problem]

The present invention has taken the following measures to solve the above problems and achieve the objectives. That is, in an IC card including a storage section for storing information and a transmitting/receiving section for transmitting/receiving information to/from an external device, a ferroelectric liquid crystal, a ferroelectric liquid crystal, a A display section formed using any one of a photochromic device (PCD), an electrochromic device (ECD), an electrophoretic display element, and a magnetic pattern display element was attached to the card.

[Effect] By taking the above measures, the following effects are achieved.

The display part is a ferroelectric liquid crystal, photochromic device (PC
D) Since it is formed using either an electrochromic device (ECD), an electrophoretic display element, or a magnetic pattern display element, there is no need to incorporate a battery into the IC card, so that no memory remains in the IC card's memory. Not only can the amount be displayed and held, but also the remaining storage amount data can be written or erased by an external device.

〔Example〕

1 and 2 are diagrams showing a first embodiment of the present invention. FIG. 1 is a perspective view of an IC card, and the IC card body 1 is formed into a card shape using insulating plastic. A connector 2 is provided at one end of the card body 1 for connection to a still video camera (not shown in this figure) which is an external device. Inside the card body 1, a memory 3 serves as a storage section for storing image data sent from a still video camera via a connector 2.
is built-in. A display section 4 using ferroelectric liquid crystal for displaying the remaining storage capacity of the memory 3 is provided at the other end of the card body 1.

The display section 4 has linearly arranged display surfaces and displays the remaining memory capacity using a bar-shaped indicator or a numerical value, so that the user can easily check it visually.

FIG. 2 is a block diagram showing the electrical configuration inside the IC card. Reference numeral 5 denotes a still video camera, which incorporates a microprocessor 6 (hereinafter abbreviated as CPU) that detects the remaining storage capacity of the memory 3 and outputs a command signal to the display section 4.

According to this embodiment configured in this way, the following effects are achieved. The remaining storage capacity of the memory 3 is detected by the CPU 6, and the display unit 4, which receives a command signal from the CPU 6 based on the detected information, displays the remaining storage capacity using a bar-shaped indicator or numerical value. At this time, writing to the display section 4 is performed using the power supply voltage of the camera 5. Display section 4
After the remaining storage capacity data of the memory 3 is written and displayed, the voltage supply from the camera 5 is stopped thereafter. At this time, since the ferroelectric liquid crystal does not require current to maintain the displayed content, the display section 4 continues to maintain the displayed content even if the supply voltage is stopped as described above. Further, when data displayed on the display section 4 is to be erased, the power supply voltage from the camera 5 is used as described above.

Therefore, according to this embodiment, since the remaining storage capacity data in the memory 3 is displayed on the display section 4 provided in the card body 1, it is possible to instantly check how much image data can be stored even during use. You can check.

Moreover, the displayed data is retained even if the power is turned off, so when checking the remaining memory capacity, you do not have to insert the IC card into the still video camera 5 each time. You can know how much memory you have left. Furthermore, since there is no need to provide a power source within the card body 1 for displaying and retaining the remaining storage capacity data, the space in the IC card body 1 can be used effectively. Note that if the memory 3 is a volatile memory, a backup power source is built into the IC card, and the stored data may be rewritten using this power source.

Although the first embodiment described above shows an example in which a ferroelectric liquid crystal is used in the display device 4, an electrophoretic element may be used instead of the ferroelectric liquid crystal. An electrophoretic element uses the property that a white colloid in a colored solvent sandwiched between two transparent electrodes moves according to its polarity when a voltage is applied to the transparent electrodes. This is an element designed to do this. Even in the display section 4 using an electrophoretic element, the display is maintained even if the supply voltage is stopped, as in the case using a ferroelectric liquid crystal. Therefore, effects similar to those of the first embodiment can be obtained.

Also, an electrochromic device (ECD) may be used instead of the ferroelectric liquid crystal. This ECD performs display by utilizing the property that the color of a substance changes reversibly due to an oxidation-reduction reaction caused by voltage application. An ECD that has been colored by applying a voltage maintains its colored state even if the voltage is not continuously applied. Therefore, in this case as well, the same effects as in the first embodiment can be obtained.

FIG. 3 is a perspective view showing a portion of the display section 10 according to the second embodiment of the present invention. The display section 10 is capable of displaying the remaining storage capacity of the memory 3, similar to the display section 4 shown in the first embodiment. This display section 10 is made by pasting a photochromic sheet onto the IC card body 1.

The photochromic sheet used here develops color when irradiated with ultraviolet rays, and the colored portion disappears when heat is applied. 11 is an ultraviolet irradiator that irradiates the display section 10 with ultraviolet rays, and 12 is a thermal head that irradiates the display section 10 with heat rays. The ultraviolet irradiator 11 and the thermal head 12 are both installed in a still video camera (not shown) facing the display section 10. In addition, ultraviolet irradiator 11. The thermal head 12 is configured to be movable in parallel along the longitudinal direction of the display section 10. The other parts have the same configuration as the first embodiment.

According to the second embodiment configured in this way, the following operation is shown. The ultraviolet irradiator 11 moves according to the remaining storage capacity of the memory 3 and irradiates the photochromic sheet forming the display section 10 with ultraviolet rays. As a result, data indicating the remaining storage capacity of the memory 3 is displayed on the display unit 10. This displayed data is retained as is even if the IC card body 1 is removed from the camera 5. In addition, when erasing the displayed data, the thermal head 12 is moved to the displayed location and heat rays are irradiated thereon.

Therefore, according to this embodiment, an IC card can be easily provided with a display function, and furthermore, no circuit for driving the display section 10 is required.

FIGS. 4(a) and 4(b) are diagrams showing a third embodiment of the present invention,
FIG. 2A is a partially cutaway perspective view of the display section 20. FIG. The display section 20 in this embodiment is composed of a magnetic sheet 21 that changes color in response to magnetism of about 300 Gauss, and a magnetic material 22 attached to the back surface of the magnetic sheet 21 opposite to the data display surface. There is. In this way, magnetization patterns 20a, 20b, etc. as shown in FIG. 2(b) are formed. The magnetic head 23 is installed in a still video camera (not shown), and is wound with windings 24a and 24b so as to apply magnetism to the magnetic material 22. The position of the magnetic head 23 is determined by the remaining storage capacity of the memory 3.

In the IC card configured in this way, the winding 24a
, 24b, the magnetic material 22 corresponding to the position of the magnetic head 23 is magnetized, and the magnetic sheet 21 at the location corresponding to the magnetized magnetic material 22 becomes, for example, as shown in FIG. 4(b). The color changes in patterns 24a, 24b and so on. As a result, the remaining storage capacity of the memory 3 is displayed.

Therefore, in this embodiment as well, effects similar to those in the second embodiment can be obtained.

FIG. 5 is a sectional view showing a modification of the third embodiment shown in FIG. 4. In this modification, a magnetic fluid 26 stored in a transparent container 25 is used instead of the magnetic sheet 21 in the third embodiment. When a predetermined position of the magnetic material 22 attached to the back surface of the display surface is magnetized by the magnetic head 23, the magnetic fine particles contained in the magnetic fluid 25 are attracted to this magnetized part, and the concentration with the non-magnetized part is reduced. Change occurs. As a result, the remaining storage capacity data of the memory 3 is displayed on the display screen.

Therefore, in this modification as well, the same effects as in the third embodiment can be obtained.

Note that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

According to the present invention, since the remaining storage capacity data of the storage section is displayed on the display section, it is possible to immediately check how much data can be stored. Moreover, the displayed data is retained even when there is no power supply, so when performing the above check, you can know the remaining memory capacity of the memory unit without having to insert the IC card into an external device such as a still video camera each time. can. Furthermore, since there is no need to equip the card with a power source for displaying and retaining the remaining storage capacity data, there is no need to include a backup battery or the like in the IC card, and space can be used effectively.

Further, a display section can be easily provided even for an IC card that does not have a built-in backup power supply, such as an IC card that has a volatile memory.

Furthermore, if a photochromic, magnetic sheet, or magnetic fluid is used as the display element of the display section, there is no need for any circuit inside the IC card to drive the remaining amount display section, so the number of elements built into the IC card is increased. This makes it possible to manufacture small-sized, large-capacity IC cards.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are diagrams showing a first embodiment of the present invention,
FIG. 1 is a perspective view of the IC card, and FIG. 2 is a block diagram showing the electrical configuration of the IC card installed in an external device. FIG. 3 is a perspective view showing the display portion of the second embodiment of the present invention, FIGS. 4(a) and 4(b) are views showing the third embodiment of the present invention, and FIG. A perspective view showing a partially cutaway portion, and FIG. 3(b) is a plan view of the display portion. FIG. 5 is a sectional view showing a modification of the third embodiment. 1...IC card body, 2...connector, 3...
Memory, 4, 10. 20... Display unit, 5... Still video camera, 6... CPU, 11... Ultraviolet irradiator, 12... Thermal head, 20a, 20b...
- Magnetization pattern, 21... Magnetic sheet, 22... Magnetic material, 23... Magnetic head, 24 a, 24 b...
・Winding wire. Applicant's representative Patent attorney Jun Tsuboi Figure 2 Figure 3 (a) (b) Figure 4 Figure 5

Claims (1)

[Claims] An IC card comprising a storage section for storing information and a transmitting/receiving section for transmitting/receiving information to/from an external device,
A ferroelectric liquid crystal, a photochromic device (PCD) so as to be able to display information including information stored in the storage section.
, an electrochromic device (ECD), an electrophoretic display element, or a magnetic pattern display element.