JPH04165583A - Non-contact id tag - Google Patents

Abstract

PURPOSE:To obtain a non-contact ID tag (RF-ID) highly reliable for storage contents by using a FUSE type or ANTI-FUSE type OTPROM as a memory element. CONSTITUTION:The FUSE type or ANTI-FUSE type OTPROM is used as the memory element comprising a built-in memory part. In the memory part, all bits are initially '0' (or 1) and changed into '1' (or 0) when data are written. Since, fusion or short-circuit is caused by writing in the OTPROM and such a change is permanent, the original state cannot be recovered once the writing has been executed. Thus, the reliability for the storage contents can be improved and the RF-ID usable for multi-purpose application can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to non-contact ID tags (hereinafter referred to as ID tags) which are used as recording media that are easy to transport and handle, for example, in entrance/exit management of buildings, logistics management of factories, etc. , RF-ID)
It is related to.

[Prior Art] Conventionally, RF-ID has been constructed with a built-in memory section for storing various information, and has been widely used because it is easy to transport and handle. As the constituting memory element, a read/write type (second conventional example) such as a mask ROM (first conventional example), an E''PROM, or a battery-backed SRAM is used.

Next, the operation will be explained.

First, in the first conventional example, when manufacturing an RF-ID, unique information is written in advance into a mask ROM, and writing or rewriting of data during use is prohibited, so that the RF-ID is designed for applications that only use fixed information. It is used.

Further, the read/write type of the second conventional example is used for applications such as coupon tickets and prepaid cards that require data to be written or rewritten during use.

[Problem to be solved by the invention]

Since the conventional RF-ID is configured as described above, in the first conventional example, the data cannot be rewritten during use, so the reliability of the stored contents is high, but the usage is limited. . In addition, in the second conventional example, the data retention time is limited, the data is lost when the battery runs out, and the stored content may change due to noise or other malfunctions, or the stored content may be tampered with by the user. It is also possible to rewrite, etc., and there are problems such as a lack of reliability of the stored contents.

This invention was made to solve the above-mentioned problems, and makes it possible to write data while in use.
The purpose is to obtain an RF-ID with high reliability regarding stored contents.

[Means to solve the problem]

The RF-ID according to the present invention uses a FUSE type or an ANTI type memory element as a built-in memory element.
- It uses a FUSE type OTFROM.

[Operation] FUSE type or ANTI-FU in this invention
In the SE type OTFROM, a write operation causes a physical permanent change in the internal wiring, so that it is impossible to change the written data.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram illustrating the operation of using a memory section in a first embodiment of the present invention, and in the figure, 1 is a write area of the memory section.

Further, FIG. 2 is a diagram explaining the operation of using the memory section in the second embodiment of the present invention, in which 2 is an address section in which each bit indicates whether or not data is recorded in the data areas 31, 32, and 33; 3 is a data section consisting of a plurality of data areas including the data areas 31, 32, and 33;
31, 32, and 33 are data areas where data is actually written.

In the memory section built into the RF-ID, all bits are initially 0 (or 1), and become 1 (or O) when written. When writing, an OTPROM will fuse or short, and these are permanent changes.
- Once written, the original state cannot be restored. By taking advantage of the characteristics of this OTPROM, it is possible to
RF-IDs using read/write type memory elements can be used in applications where reliability has been a problem.

For example, this is a case where the usage information is changed and stored on a card such as a ride ticket or a prepaid card, and it is undesirable for the user to illegally rewrite the information.

In the first embodiment, the user only has to write 1 to write area 1 of the memory section as shown in FIG. 1(a) each time it is used (FIG. 1(b)), and the user can Even if an attempt is made to rewrite the recorded contents, it will only be possible to write in a direction disadvantageous to the user.

Next, a second example will be described.

In the first embodiment, when recording complicated information, the number of bits to be stored at one time is fixed and data is added sequentially. In order to find the location of the memory section, it is necessary to read out all past memory contents, which takes time, and if the memory contents are all 0 (or 1) by chance, the initial value of the memory section may not be distinguishable. Therefore, as shown in FIG. 2, an address section 2 indicating the location of the latest data and a data section 3 storing the complex data are provided in the memory section. Examples of applications with a large amount of information include personal medical records, automobile maintenance records, and bank passbooks.

The contents of the memory section built into the RF-ID are as follows:
Since testing cannot be performed when the RF-ID is manufactured, it can be confirmed that all bits are O (or 1) initially, but there is a risk that an error may occur in which writing is not possible even if an attempt is made to write. Therefore, reading is always performed after writing, and by verifying whether the writing was correct, rewriting is performed if there is an error.

FIG. 3 shows a third embodiment in which, for example, in the first embodiment, 1 is written to bit 1b next to defective bit 1 (represented by X in the figure, the actual value is 0). FIG. 6 is a diagram showing the operation of using the example, and according to this third embodiment, the total number of 1's can be set to a desired number of bits.

Similarly, in the case of the second embodiment, the fourth
According to the embodiment, the data written in the data section 3 is read out, and if the data is correct, 1 is written in the corresponding bit of the address section 2, and the contents of the address section 2 are also read to check whether 1 was written correctly. Check. Therefore, if there is an error in either data section 3 or address section 2 (
2a, 32a) in the figure performs writing again in the above procedure using the next location of the data section 3 and address section 2.

This makes it possible to obtain extremely high reliability of stored contents.

[Effects of the Invention] As described above, according to the present invention, a FUSE type or ANTI-FUSE type OTPROM is used as the memory element constituting the memory section built into the RF-ID, so that the Along with being able to write,
This has the effect of improving the reliability of stored contents and providing an RF-ID that can be used for a variety of purposes.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram for explaining the operation of using the memory section in the first embodiment of the present invention, FIG. 2 is an explanatory diagram for explaining the operation of the use section of the memory section in the second embodiment of the invention,
FIG. 3 is an explanatory diagram for explaining the operation of using the memory section in the third embodiment of the present invention, and FIG. 4 is an explanatory diagram for explaining the operation of using the memory section in the fourth embodiment of the invention. In the figure, 1 is a storage area, 2 is an address section, and 3 is a data section. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a non-contact ID tag that has a built-in memory section for storing various information and is used as a transportable storage medium, a FUSE type or ANTI-FUSE type OTPROM is used as a memory element constituting the memory section. Features a contactless ID tag.