JPH03126192A - Light reflection type key card with reading level setting code and reading level setting device - Google Patents

Abstract

PURPOSE:To set a light quantity optimum for reading at the preceding stage of the reading of a key code and to accurately read the key code by providing a code for light quantity level setting. CONSTITUTION:The key code 1b comprised of first and second elements with different light reflectance provided at a key card 1 is irradiated with light, and the key code 1b is read based on the difference of the light reflectance, and locking/unlocking is performed according to a read key code 1b. A code 1a for reading level setting to set the reading reference values of the first and second elements of the key code 1b is provided separately from the key code 1b. Thereby, it is possible to prevent malfunction in a reader occurring due to the change of density of the key code 1b printed on the key card 1 and the dispersion of characteristic of a light emitting element irradiating the key card 1 with the light and a light receiving element to converge reflected light from the key card 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a light reflective key card with a code for setting a reading level and a reading level setting device. More specifically, a light-reflective key card provided with an auxiliary code for determining the reading standard value of the key code provided on a card type key, and a light reflecting type key card provided with an auxiliary code for determining the reading standard value of the key code by reading the auxiliary code. This invention relates to a reading level setting device for.

(Prior Art) Electronic lock systems that electronically lock and unlock doors using a card-type key (hereinafter referred to as a "key card") have been known. A key code for unlocking the door is written on the key card, and a reader attached to the door reads this key code and compares it with the code assigned to the door. As a result of the comparison, if they match, an unlocking permission signal is generated and the locking mechanism is activated to unlock the door.

As this type of key card, so-called magnetic type or transmission type optical type are conventionally known. A key code is magnetically written on the magnetic key card, and the key code is read with a magnetic head to unlock the door.

A transmission type optical key card has an array pattern of transparent holes representing a key code formed on the card substrate, and the key code is read by irradiating the card with light and detecting the transmitted light. Magnetic key cards have the disadvantage that the key card itself is easily affected by external magnetism, and if the key card is not inserted accurately, read errors are likely to occur on the reader side. Transparent key cards also have the disadvantage that the amount of information that can be stored on a single key card is relatively small, and many types of key cards cannot be issued.

Therefore, the applicant has proposed an electronic lock system using an optical reflective key card that is not affected by external magnetism and has a relatively large storage capacity ("electronic lock system"). (filed on August 22, 1999), an optical reflective key card uses, for example, a thermal transfer printing ribbon and printing printer to encrypt the key code and print it on the key card. The key code is read based on the difference in light reflectance between the printed surface and the card surface.

(Problem to be Solved by the Invention) However, if the key code printed on the key card is worn out, damaged, or dirty due to friction, the amount of reflected light will decrease even if the amount of irradiated light is constant. The key code may not be read accurately. - On the other hand, the characteristics of the light-emitting element that illuminates the key card and the light-receiving element that collects the reflected light from the key card vary depending on the product, making it impossible to read accurately and causing the reading device to malfunction. Such a situation is expected.

(Means for Solving the Problems) The present invention has been made based on the above considerations, and includes changes in the density of a key code printed on a key card, a light emitting element that irradiates light onto the key card, and a key card. This is intended to prevent malfunctions of the reading device due to variations in the characteristics of the light-receiving element that collects reflected light from the light receiving element.

In the present invention, light is irradiated onto a key code that is provided on a key card and is composed of first and second elements having different light reflectances,
The optical reflective key card reads a key code based on the difference in light reflectance between the first and second elements, and locks and unlocks the door according to the read key code. The above object is achieved by providing a reading level setting code separate from the key code for setting the reading reference value of the element.

The reading level setting code is composed of first and second elements having different light reflectances.

A reading level setting device for reading a reading level setting code and setting a reading reference value of a key code according to the reading result, the reading level comprising first and second elements having different light reflectances. an irradiation means for irradiating the setting code with light; a light receiving means for receiving the reflected light of the light irradiated on the first and second elements of the reading level setting code; A reading level setting device comprising a control means for determining a reading reference value for the key code based on the output from the light receiving means when the amount of reflected light from the first and second elements becomes equal, reads the reading level setting code. Reads light-reflective key cards.

(Operation) A reading level setting code is read before starting reading of the key code necessary for unlocking, and the reading reference level of the key code is determined based on the read result. Once the reading reference level is determined, the key code is subsequently read at the determined level. For example, the amount of light emitted by the light emitting element, that is, the amount of current supplied to the light emitting element, is regulated to ensure accurate reading of the key code.

(Example) Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an example of a key card to which a light level setting code is added. As shown in FIG. 1(a), the key card 1 is inserted into the key card insertion slot of the reader in the direction of the arrow. On the key card 1, data D1 to D4 consisting of four channels are printed along the card insertion direction together with a clock. The data D1 to D4 include a light level setting code 1a and a reading code 1b. In addition to the key code, the reading code lb can include necessary information depending on the purpose of use of the key card. For example, when using key card 1 as a hotel lock system, the guest room number,
Information such as the guest's checkout date may be included.

In FIG. 1, the black part shows the part printed with the thermal transfer ink ribbon, and the white part shows the key card surface which is not printed with the ink ribbon. That is,
The black portions in the figure are portions where the irradiated light is reflected with low efficiency when irradiated with light, and the white portions are portions where the irradiated light is reflected with high efficiency. Printed data is read based on this difference in reflectance.

Each of the data D1 to D4 and the clock are expressed by a pattern of white and black parts, and the clock is printed in the center of the key card l in a regular pattern with white parts and black parts alternately and regularly. Data D1 to D4 are printed in two channels on each side of the clock. The white part and the black part constituting the data D1 to D4 are arranged in the key card insertion direction so that the center position of each coincides with the edge part of the white part and the black part constituting the clock, that is, the boundary part between the white part and the black part. are arranged in The clock moves from the white part to the black part
Alternatively, data is read by determining whether the data on both sides is white or black at the timing when the black part changes to the white part (edge part).

FIG. 2 is a block diagram showing a light amount setting circuit 2 for setting the optimum light amount, and this circuit is provided integrally with the reading device.

The light amount setting circuit 2 includes a current setting circuit 3, a light emitting diode drive circuit 4, a light emitting diode 5, a light receiving diode 6, an amplifier 7, a comparator 8, and a control section 9. The light emitting diode 5 and the light receiving diode 6 are arranged in a positional relationship as shown in FIG. That is, the light emitting diode 5 emits light toward the key card l, and the light reflected on the key card l is arranged so as to be incident on the light receiving diode 6 arranged on the same side with respect to the key card 1. There is. A pair of light emitting diode 5 and light receiving diode θ is provided for each channel of clock and data Di to D4.

The operation of the light amount setting circuit 1 will be explained with reference to FIGS. 2 and 6.

After the control unit 9 is initialized (step 1), it enters a standby mode (step 2) and waits for the key card 1 to be inserted. The key card 1 is inserted and the blank area at the front end of the card is detected. Along with this, the control unit 9 is activated by receiving power supply voltage from a battery (not shown). The insertion of the key card 1 is detected by a card detection switch (not shown) installed in the key card insertion slot of the reader.
It can also be done physically. When insertion of the key card 1 is detected (step 3), a voltage checking circuit (not shown) is activated to perform a battery check (step 4). In parallel with the battery check, the power supply voltage of the battery is controlled to a predetermined value and then supplied to each part of the control section 9 and the light amount setting circuit 2.

Key card 1 has light emitting diode 5 and light receiving diode 6
When the controller 9 is inserted between the keys and the controller 9 is activated, the light level setting code 1a on the key card l is read and the current level flowing through the light emitting diodes 5 provided for each of the clock and data D1 to D4 is adjusted (step 5). ).

The reading device detects the edge part ■ where the leading margin of the key card 1 transitions to the first black part of the clock (see Figure 1).
(see b)), recognizes the start of reading the light intensity level setting code 1a.

When the key card 1 is further inserted, the light emitted from the first black part of the clock to the next white part is received by the light receiving diode θ.The output voltage at the light receiving diode 6 changes from low level (L) to high level ( H) (■ in Figure 1(b)).

At this timing, the light amount level setting codes of data D1 to D4 are sequentially read. The data D1 to D4 at this time are all set to white in advance.

The control unit 9 reduces the current value flowing through the light emitting diode 5 stepwise and at high speed. Regarding the white portion, if the value of the current flowing through the light emitting diode 5 is reduced, the amount of light emitted from the light emitting diode 5 will be reduced approximately in proportion to the decrease in the current value. Along with this, the amount of light reflected from the white portion decreases as shown in FIG. 4(a), and as the amount of reflected light decreases, the output voltage of the light receiving diode 6 gradually changes as shown in FIG. 4(b). decreases to The output voltage from the light receiving diode 6 is amplified each time by an amplifier 7, the amplified signal is compared with a first reference value by a comparator 8 in the next stage, and a digital signal output according to the comparison result is sent to the control section. 9 and stored in the internal memory of the control unit 9.

The first reference value in the comparator 8 is set to a value (for example, 1.2 volts) that allows determination of white areas. Then, the current flowing through the light emitting diode 5 when the output voltage of the light receiving diode 6 becomes 1.2 volts or less is determined.

When the key card 1 is inserted deeper, the clock light emitting diode 5 emits light from the white part to the next black part. Accordingly, the output voltage at the light receiving diode 6 changes from high level (H) to low level (L) (■ in FIG. 1(b)).

At this timing, the light amount setting codes of data D1 to D4 are sequentially read. The data D1 to D4 at this time are all set to black in advance.

Regarding the black portion, the value of the current flowing through the light emitting diode 5 is increased in stages. When the current value is increased, the amount of light emitted from the light emitting diode 5 increases almost in proportion to the increase in the current value. Along with this, as shown in Figure 4(a),
The amount of reflected light from the black portion increases, and as the amount of reflected light increases, the output voltage of the light receiving diode 6 increases stepwise as shown in FIG. 4(b). The output voltage from the light receiving diode 6 is amplified each time by an amplifier 7, the amplified signal is compared with a second reference value by a comparator 8 in the next stage, and a digital signal output according to the comparison result is sent to a controller 9. and stores it in the internal memory of the control unit 9.

The second reference value in the comparator 8 is set to a value (for example, 0.12 volts) that allows a black portion to be determined. Then, the current flowing through the light emitting diode 5 when the output voltage of the light receiving diode 6 exceeds 0.12 volts is determined.

As described above, the amount of light emitted by the light emitting diode 5, that is, the amount of current supplied when the light receiving diode 6 outputs 0.12 volts in response to the reflected light from the black part, and the amount of light received in response to the reflected light from the white part. The first and second reference values are appropriately set so that when the diode 6 outputs 1.2 volts, the amount of light emitted from the light emitting diode 5, that is, the amount of supplied current, is between -.

Assuming that the amount of current supplied to the light emitting diode 5 is 50 milliamps and 500 milliamps for the white part and the black part, respectively, the control unit 9 calculates the intermediate value (225 milliamps) between 500 milliamps and 50 milliamps,
This value is set as the current supplied to the light emitting diode 5. 225
If a current of around milliampere is passed through the light emitting diode 5,
This is because white parts and black parts can be accurately distinguished. The above setting of the current level of the light emitting diode 5 is performed for each channel.

Once the light intensity level of the light emitting diode 5 is set, the key code is then read (step 6). A digital signal representing the key code is input from the comparator 8 to the control unit 9, and the key code is decrypted (step 7).

The control unit 9 further compares the key code with a predetermined code stored in the built-in memory, and generates an unlock permission signal or an unlock disapproval signal depending on the comparison result, and performs card processing ( Step 8). When the unlock permission signal is generated, the solenoid (
(not shown) is driven. A locking mechanism (not shown) is connected to the solenoid, and when the solenoid is activated, the outdoor handle (not shown) is brought into interlocking state with the locking mechanism and unlocked (step 9). When the unlocking process is completed, the routine returns to step 2 and enters a standby mode in which it waits for the next key card l to be inserted (step 2).

Although the case where the amount of light is set by changing the current flowing through the light emitting diode 5 has been described above, the present invention is not limited to this. The light amount level can be set by changing the reference value of the comparator 8 or by changing the quantization level using an A/D converter instead of the comparator 8.

(Effects of the Invention) As explained above, according to the present invention, by providing the code for setting the light intensity level, it is possible to set the optimal light intensity for reading in the stage before reading the key code. Key codes can be read accurately even if the printed key code is worn out, scratched, or soiled, and the amount of reflected light is reduced. Further, variations in characteristics of the light emitting element and light receiving element of the reading device can be absorbed, and a highly reliable reading device can be provided.

[Brief explanation of the drawing]

Figure 1 (a) is a diagram showing various codes formed on the optical reflective key card, Figure 1 (b) is the clock signal waveform on the key card Figure 1 (C) is the key card A signal waveform diagram of the above data, FIG. 2 is a block diagram showing the light intensity setting circuit of the reading device according to the present invention, and FIG. 3 is a diagram showing the positional relationship between the light emitting diode and the light receiving diode in the reading device. Figure 4 (a) and (b)
Figure 5 is a diagram to explain the procedure for setting the optimum light amount, Figure 5 is a diagram to explain the setting of the current value flowing to the light emitting diode, and Figure 6 is a flowchart to explain the operation sequence of the reading device. It is.・Light emitting diode ・Light receiving diode ・Amplifier ・Comparator ・Control unit

Claims (3)

[Claims] (1) Light is irradiated onto the key code, which is made up of first and second elements with different light reflectances, provided on the key card, and the light is detected based on the difference in light reflectance between the first and second elements. An optical reflective key card that reads a key code and unlocks the lock according to the read key code, and includes a read level setting code for setting the reading reference value of the first and second elements of the key code. A light reflective key card with a code for setting a reading level, characterized in that the key code is provided separately from the key code. (2) The light reflective key card with a reading level setting code according to claim 1, wherein the reading level setting code is constituted by first and second elements having different light reflectances. (3) A reading level setting device for reading a reading level setting code and setting a reading reference value for a key code according to the reading result, which is composed of first and second elements having different light reflectances. irradiation means for irradiating light onto the reading level setting code; light receiving means for receiving reflected light of the light irradiated to the first and second elements of the reading level setting code; and reading level setting. and a control means for determining a reading reference value for the key code based on the output from the light receiving means when the amounts of reflected light from the first and second elements of the key code are equal. Setting device