KR100461644B1 - A key scan circuit - Google Patents

Abstract

The present invention relates to a key scan circuit, and more particularly, to a key scan circuit capable of recognizing an operation function input by a user. According to the present invention, the fluorescent display device includes an anode scan port, and the A / D option port reads the signal output to the anode scan port.

The key scan circuit according to the present invention stably outputs a scan output waveform until a figure or character corresponding to an operation function input by a user through a fluorescent display device is produced by using one A / D option port. We can expect the unit price to fall.

Description

A key scan circuit

The present invention relates to a key scan circuit, and more particularly, to a key scan circuit configured to stably output a scan output waveform to a product equipped with a fluorescent display device.

Hereinafter, a key scan circuit according to the present invention will be described using a microwave oven as an embodiment.

In general, a microwave oven refers to a cooker that uses electric power to drive a heater or a magnetron and generates microwave waves or heat to cook. In particular, microwaves are easily used in homes, businesses and convenience stores because they cook easily within a very short time.

In addition, in recent years, the population of microwave ovens is rapidly increasing so that many households have microwave ovens. In addition, as the range of cooking available in microwave ovens is widening, the utilization of microwave ovens is expected to continue to increase.

In using a microwave oven as described above, in order to use it more widely and conveniently, it was necessary to have many keys in the microwave oven. For example, a key function such as automatic cooking, manual cooking, other thawing and warming should be provided as an upper function, and many function keys such as popcorn cooking, steamed egg custard, potato boiling, and pizza cooking are also required in the lower function of the automatic cooking. It was. And many such keys are configured to generate a signal for each cooking.

Hereinafter, a key scan circuit according to the related art will be described.

FIG. 1A is a key input circuit according to the prior art configured as a port to port matrix, and FIG. 1B is a key scan circuit according to the prior art in which a key matrix is formed by connecting to a grid portion.

First, as shown in FIG. 1A, a microcontroller 30 capable of sensing a signal to control a functional operation of a product, a key panel 35 constituting a plurality of key switches, and a product specification It consists of an option circuit 40.

In the key scan circuit configured as described above, the key panel 35 portion is composed of a matrix. In addition, the option circuit 40 is also connected to the option port P10 provided in the microcontroller 30 is configured alone.

Looking at the connection relationship of the control configuration of Figure 1a in more detail, a plurality of signal sensing ports (P1 ~ P10) is provided in the microcontroller, the first resistor (R1 ') of the first port (P1) of the ports This is connected. The first resistor R1 ′ is connected to the key panel 35.

In addition, the second port P2 of the ports provided in the microcontroller 30 is connected to the second resistor R2 '. The second resistor R2 ′ is connected to the key panel 35. As described above, the third port P3 of the microcontroller 30 is connected to the third resistor R3 ', and the fourth port P4 is the fourth resistor R4' and the fifth port ( P5 is connected to the fifth resistor R5 '. Each of the third resistor R3 ', the fourth resistor R4', and the fifth resistor R5 'connected as described above are connected to the key panel 35.

Meanwhile, the sixth port, the seventh port, the eighth port, and the nineth port of the microcontroller 30 are connected to the key panel 35. The key panel 35 is a key switch composed of a 4 × 5 matrix, and the intersection of each matrix is composed of a key switch. The keyswitch is switched on according to an operation function input by a user, and a signal is input to the microcontroller 30 according to the switching of the keyswitch. Therefore, the microcontroller 30 that senses the signal recognizes the operation function input by the user and controls the operation of the microwave oven. Meanwhile, port 10 of the microcontroller 30 port P10 is configured as an option port.

Referring to the operation of the key scan circuit configured as described above, it can be represented as follows.

When the user inputs a control signal to operate the microwave oven to perform cooking, the control signal is input through the key panel 35. Accordingly, the control signal input through the key panel 35 is input to the microcontroller 30 due to the switching operation of the key panel 35 composed of a matrix as shown in the figure.

At this time, the control signal input to the port provided in the microcontroller 30 is input differently due to the matrix control switching according to the operation function input by the user. Accordingly, the microcontroller 30 recognizes the control signal and controls the operation of the microwave oven accordingly to allow the heating to proceed.

On the other hand, as shown in Figure 1b, when the power is input to the product, the option portion 57 for determining the specification of the product, a microcontroller 45 that can detect the signal to control the functional operation of the product, A key panel 50 constituting a plurality of key switches, and a fluorescent display device 55 for displaying an operation function input by the user.

Hereinafter, the control configuration will be described in detail.

The microcontroller 45 includes ten ports P1 to P10, and the fluorescent display 55 includes first grid ports G1 to seventh grid ports G7. In addition, the microcontroller 45 and the fluorescent display device 55 are connected to each other by a scan line.

On the other hand, a key panel 50 composed of a 7 × 6 matrix is provided, and the key input ports P9 and P10 of the microcontroller 45 are connected to the end of the key panel 50. The hot end of the key panel 50 is connected to the above-described scan line. At this time, between the key panel 50 and the scan line, the transistors Q80 to Q96 and the diodes D80 to D86 are configured as shown in FIG. 1B.

The scan output waveform output from the microcontroller 45 is transmitted to grid terminals G1 to G7 of the fluorescent display device 55 through grid scan lines. In this case, as described above, the scan waveform transmitted through the grid scan line has a very high power consumption and is unstable, and thus may not normally be recognized by the key panel 50 corresponding to the operation selected by the user. In order to prevent this, the transistors Q80 to Q96 and the diodes D80 to D86 are connected to the key panel 50 stably.

Therefore, when a user inputs an operation control signal through the key panel 50, the corresponding key switch provided in the key panel 50 is turned on according to the signal input. As a result, only the corresponding control signal connected by the on switching operation among the scan waveforms output through the scan line is transmitted to the key input ports P9 and P10.

Accordingly, the microcontroller 45 recognizes the operation control signal input by the user and controls the product to operate. Accordingly, the product operates under the control of the microcontroller 45, and output control is performed such that the operation control function input by the user from the fluorescent display device 55 is displayed.

At this time, the microcontroller 45 is provided with a separate option port (P8). The option port P8 is connected to the scan line to sense the voltage level of the scan signal output from the microcontroller 45 to the fluorescent display device 55. In addition, the microcontroller 45 that detects the voltage level of the scan signal grasps the specification and operation characteristics of the product according to the voltage level and controls the product to operate normally.

However, the key scan circuit according to the prior art has the following problems.

In the past, as a separate option port is allocated and processed as shown in FIG. 1A, the option port is used in the microcontroller, resulting in a price increase factor of the microcontroller. In addition, in the related art, a single port is used, and the number of ports according to a key is large, which is complicated in hardware.

In addition, the scan output waveform output to the grid terminal of the conventional fluorescent display device of FIG. 1B is not stable and reacts very sensitively to environmental changes, and the voltage output level is irregularly output.

Accordingly, an object of the present invention is to provide a key scan circuit for stably outputting a kisscan output waveform.

It is also an object of the present invention to provide a key scan circuit that simplifies the configuration of hardware.

1A is a key input circuit according to the prior art.

1B is a key scan circuit according to the prior art.

2 is a key scan circuit according to the present invention;

3A is a grid scan output waveform diagram output from a microcontroller configured in a key scan circuit in accordance with the present invention.

3B is an anode scan output waveform diagram output from a microcontroller constructed in a key scan circuit in accordance with the present invention.

Fig. 3C is a waveform diagram showing the output time of this grid scan waveform and anode scan waveform.

4 is an operation control flow diagram illustrating a process of operation control of the scan circuit according to the present invention.

Explanation of symbols on the main parts of the drawings

60: key panel 70: microcontroller

80: fluorescent display device

The key scan circuit according to the present invention for achieving the above object comprises a microcontroller for outputting a signal for display to the anode scan line and grid scan line; A fluorescent display device for inputting and displaying signals outputted from the anode scan line and the grid scan line; A key panel configured to connect a plurality of key switches to an anode scan line between the microcontroller and the fluorescent display device; And an A / D option circuit connected to an anode scan line between the microcontroller and the fluorescent display device, and sensing an anode scan signal output to the fluorescent display device when power is supplied to the microcontroller.

Hereinafter, a key scan circuit according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a key scan circuit of a microwave oven according to the present invention.

As shown in the drawing, when power is input to the product, an option circuit A for determining the specifications and operation characteristics of the product, a key panel 60 for the user to input an operation control signal of the microwave oven, and a microwave oven A microcontroller 70 for recognizing a signal according to an operation function of the control unit and outputting a corresponding signal to a user, and a fluorescent display for displaying an operation function input by the user according to a signal controlled by the microcontroller 70. Device 80 is configured.

Looking at the connection relationship of the scan circuit according to the key input of the microwave oven configured as described above in detail as follows.

Between the microcontroller 70 and the fluorescent display device 80, the grid terminals G1 to G7 and the anode terminals P1 to P7 are connected to respective ports through the grid scan line GL and the anode scan line AL, respectively. It is connected.

In addition, a key panel 60 composed of a 7 × 6 matrix is provided, and the first to seventh column ports 01 to 07 of the key panel are connected to the heat scan lines a1 to a7, and the keys The eighth row ports to the thirteenth row ports 08 to 13 of the panel are connected to the row scan lines b1 to b6.

On the other hand, the key panel 60 is configured as described above is connected to the microcontroller 70. The microcontroller 70 is provided with two ports P21 and P22 to receive the row signal of the key panel 60 through the row scan lines b1 to b6.

The two ports P21 and P22 will be described in more detail. The eighth row port 08 of the key panel 60 is connected to the twentieth resistor R20. The ninth row port 09 is connected to the twenty-first resistor R21, and the twenty-first resistor R21 is connected between the ninth row port 09 and the twentieth resistor R20. In addition, the tenth row port 10 is connected to the twenty-second resistor R22, and the twenty-second resistor R22 is connected between the tenth row port 10 and the twenty-first resistor R21.

The twentieth resistor R20 is connected to the twenty-first port P21 provided in the microcontroller 70, and a first capacitor C1 is disposed between the twelfth resistor R20 and the twenty-first port P21. It is provided. The other side of the first capacitor C1 is grounded.

Meanwhile, the eleventh row port 11 of the key panel 60 is connected to the twenty-third resistor R23. The twelfth row port 12 is connected to the twenty-fourth resistor R24, and the twenty-fourth resistor R24 is connected between the twelfth row port 12 and the twenty-third resistor R23. In addition, the thirteenth row port 13 is connected to the twenty-fifth resistor R25, and the twenty-fifth resistor R25 is connected between the thirteenth row port 13 and the twenty-fourth resistor R24.

The twenty-third resistor R23 is connected to a twenty-second port P22 provided in the microcontroller 70, and a second capacitor C2 is disposed between the twenty-third resistor R23 and the twenty-second port P22. It is provided. The other side of the second capacitor C2 is grounded.

Meanwhile, among the first to seventh column ports 01 to 07 provided in the key panel 60, the first column port 01 is connected to the first diode D1. The first diode D1 is connected to the eleventh resistor R11 in series. In addition, the second column port 02 is connected to the second diode D2. The second diode D2 is connected in series with a twelfth resistor R12. The third column port 03 is connected to the third diode D3. The third diode D3 is connected in series with a thirteenth resistor R13. The fourth column port 04 is connected to the fourth diode D4, and the fourth diode D4 is connected in series with the fourteenth resistor R14. The fifth column port 05 is connected to the fifth diode D5, and the fifth diode D5 is connected in series with the fifteenth resistor R15. The sixth column port 06 is connected to the sixth diode D6, and the sixth diode D6 is connected to the sixteenth resistor R16. In addition, the seventh column port 07 is connected to the seventh diode D7, and the seventh diode D7 is connected to the seventeenth resistor R17.

In addition, the aforementioned eleventh resistor R11 is connected to the first anode scan line AL1 connecting between the microcontroller 70 and the fluorescent display device 80, and the twelfth resistor R12 is connected to the second anode. The scan line AL2, the thirteenth resistor R13 are the third anode scan line AL3, the fourteenth resistor R14 is the fourth anode scan line AL4, and the fifteenth resistor R15 is the fifth The anode scan line AL5, the sixteenth resistor R16 are connected to the sixth anode scan line AL6, and the seventeenth resistor R17 are connected to the seventh anode scan line AL7, respectively.

On the other hand, the microcontroller 70 is provided with an option port (P20), the option port (P20) is connected to a plurality of resistors (R1 ~ R6) configured in parallel. That is, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are connected in parallel. The plurality of resistors are connected to diodes D8 to D12, respectively. That is, the sixth resistor R6 is the eighth diode D8, the fifth resistor R5 is the ninth diode D9, the fourth resistor R4 is the tenth diode D10, and the third resistor. R3 is connected to the eleventh diode 11 (D11) and the second resistor R2 is connected to the twelfth diode D12.

The diodes D8 to D12 are connected to heat scan lines a1 to a7 that transmit scan signals between the microcontroller 70 and the fluorescent display device 80 from the heat scan port of the key panel 60. . That is, the twelfth diode D12 and the third column scan line a3 are connected. The eleventh diode D11 is connected to the fourth column scan line a4, the tenth diode D10 is connected to the fifth column scan line a5, and the ninth diode D9 is connected to the sixth column scan line. The eighth diode D8 is connected to the seventh column scan line a7.

Accordingly, the A / D option circuit A senses the signal output to the anode scan line, and the option port P20 provided in the microcontroller 70 due to the resistance configured in the A / D option circuit A. FIG. The voltage value delivered to is different. The microcontroller 70 grasps product specifications, operating characteristics, etc. according to the recognized voltage value.

FIG. 3A shows a grid scan output waveform output from the microcontroller, FIG. 3B is an output waveform diagram showing the anode scan output waveform output from the microcontroller, and FIG. 3C shows the output time of the present grid scan waveform and the anode scan waveform. It is a waveform diagram.

As shown in FIG. 2, when the microcontroller 70 outputs the scan output waveforms to the grid ports G1 to G7 and the anode ports P to P7 of the fluorescent display device 80, FIGS. 3A, 3B, and 3C. The scan output waveform as shown in FIG. That is, as shown in FIGS. 3A and 3B, the scan signal is output to the grid ports G1 to G7 and the anode ports P1 to P7 at regular intervals, and the fluorescent display device 80 receiving the signal receives the scan output. Output as figure or character according to signal.

First, referring to the grid scan output waveform output to the grid port of FIG. 3A, the scan output signal outputs an on signal for a period t1. The scan output signals output as described above are sequentially input to respective ports provided in the grid terminals G1 to G7. When the scan output control signal input to the first grid port G1 is turned off after the t1 cycle on switching operation after s1 hours, a scan output having a t1 cycle to the second grid port G2 is simultaneously performed. The control signal is on switching operation.

When the grid scan output waveform output as described above is output from the first grid port G1 to the seventh grid port G7 and the scan waveform output process is completed, the first anode port provided in the microcontroller 70 at the same time. An anode scan waveform having a period t1 at (P1) is output on. As described above, the scan output waveform output from the first grid port G1 to the seventh grid port G7 is repeated, and when the above steps are repeated, the scan output waveforms are respectively applied at the respective anode ports G1 to G7. This happens.

The operation control process of the key scan circuit will now be described with reference to the control configuration of FIG. 2 and the scan output waveforms of FIGS. 3A, 3B, and 3C.

When power is supplied to the product, scan waveforms are sequentially output from the first grid port G1 to the seventh grid port G7 of the fluorescent display device 80 included in the control circuit of the scan circuit. As described above, when the grid scan waveform output from the first grid port G1 to the seventh grid port G7 is completed, the scan waveform is output from the first anode port P1 as shown in the drawing.

That is, as illustrated in FIG. 3C, a scan waveform having a t1 period is output from the first grid port G1 to the seventh grid port G7. At this time, the first grid port G1 outputs the t1 scan waveform after s1 hours until the scan waveform having the t1 cycle is output, and the second grid port G2 outputs the scan waveform having the t1 cycle. After s2 hours, the scan waveform is output. As described above, the grid ports G1 to G7 output scan waveforms having a period t1 after a predetermined time period s1 to s7, respectively. As a result, the scan ports having the period t1 are sequentially switched on. Have When the output of the grid scan waveform as described above is completed, the first anode port P1 outputs a scan output waveform having a period t1.

The output control process of the scan waveform described above indicates that the scan waveform is output from the first anode port P1 when the scan waveform is output from the first grid port G1 to the seventh grid port G7. Each of the second anode port P2 to the seventh anode port P7 is also repeated to show the same output control flow of the scan waveform as described above.

Therefore, the A / D option circuit A configured in the scan circuit detects the output voltage of the scan waveform output through the anode scan line AL through the option line OL when power is supplied to the product. The product is determined according to the voltage level of the voltage value sensed through the option line OL, and the microcontroller 70 can control the operation function on the product. In this case, the reason why the A / D option circuit A is provided as described above is that one type of microcontroller 70 is often used in various products, and accordingly, it is possible to control the operation according to the type of product. To do that.

Accordingly, as described above, the scan signal is transferred from the eighth diode D8 to the twelfth diode D12 provided in the A / D option circuit A to distribute the sixth resistor R6 from the second resistor R2. According to the voltage signal is transmitted through one option port (P20) provided in the microcontroller 70, the microcontroller detects the transmitted signal and operates by identifying the specifications of the product according to the detected voltage level of the signal To control.

On the other hand, when the user selects the desired operation control function through the key panel 60, the signal is transmitted to the microcontroller 70 so that the product operation control according to the operation function selected by the user. As shown in the figure, the key panel 60 is provided with switches according to various operation control functions, and when a user selects one of the operation functions, the signal is provided in the microcontroller 70. It is transmitted to the key input ports 1 and 2 (P21 and P22).

For example, if the pop corn cook (POP CORN) is selected from the operation control functions provided in the key panel 60, the switch is closed, and the high signal output from the fifth line of the anode scan line AL is displayed in the fifth column. The signal is transmitted to the scan line a5 and connected to the fifth column port 05 of the key panel. On the other hand, a signal is output to the tenth row scan line b3 connected to the fifth column scan line a5 and transmitted to the signal sensing circuit B, and the resistor R20 is provided in the signal sensing circuit B. Through the distribution of ˜R22, the signal is transferred to the signal detection port P21 provided in the microcontroller 70.

Therefore, the microcontroller 70 receiving the signal recognizes the operation control signal input by the user and controls the operation of the product to operate the function according to the signal. At the same time, the operation function corresponding to the high signal output through the above-mentioned line 5 of the anode scan line AL is output to the fluorescent display device 80 as a figure or a character.

An operation control of a key scan circuit that outputs a scan waveform as described above is as follows.

4 is an operation control flowchart of a key scan circuit according to the present invention.

When power is applied to the product (step 100), the grid scan output waveform is output to the grid ports G1 to G7 of the fluorescent display device 80 through the grid terminals G1 to G7 of the microcontroller 70. As shown in FIG. 3, when the grid scan output waveform is output from the first grid port G1 to the seventh grid port G7, the anode scan output waveform is output from the first anode port P1. As described above, the grid scan output waveforms from the first grid port G1 to the seventh grid port G7 are repeatedly output from the first anode port P1 to the seventh anode port P7 (step 110). .

At this time, the A / D option circuit A shown in FIG. 2 reads the voltage level of the scan output waveform output as described above (step 120). When the voltage level value is recognized (step 130), the specification of the product and its operation control are performed.

As described above, the user inputs an operation function of the product through the key panel 60 while the scan output waveform is output (step 140). Accordingly, the operation control signal is transmitted to the anode scan line as shown in FIG. At this time, the signal according to the operation control function transmitted to the anode scan line through the on (on) operation of the switch configured in the key panel 60, the first signal detection ports (P21, P22) of the microcontroller 70 Is passed on. Due to the transmitted control signal, the microcontroller 70 controls the function corresponding to the operation control signal to operate. In addition, the microcontroller 70 controls the figure or character according to the operation function to be displayed through the fluorescent display (step 150).

As described above, the present invention has a basic technical concept of controlling the scan output waveform to be stably output from the key scan circuit to the fluorescent display device.

In the description of the key scan circuit according to the present invention, the key scan circuit of the microwave oven has been described as an example, which is one embodiment, and can be used in all home appliances equipped with a fluorescent display device including a microwave oven.

Accordingly, the right of the present invention is not limited to the above-described embodiment but is defined by the claims, and those skilled in the art can make various modifications and adaptations within the scope of the claims. It is self-evident.

Therefore, the following effects can be expected due to the present invention.

The key scan circuit according to the present invention has an anode port for stably outputting a scan output waveform until a figure or character corresponding to an operation function input by a user is output through a fluorescent display device.

This eliminates the need for transistors and diodes, compared to the prior art, until the A / D option circuit senses the signal output to the anode port, simplifying the process and simplifying the hardware configuration.

In addition, due to the large number of anode ports configured in the fluorescent display device according to the present invention, the number of cases connected to the key panel is increased, and as a result, a large number of operation keys can be secured.

Claims (2)

delete A microcontroller for outputting a signal for display to the anode scan line and the grid scan line; A fluorescent display device for inputting and displaying signals outputted from the anode scan line and the grid scan line; A key panel configured to connect a plurality of key switches to an anode scan line between the microcontroller and the fluorescent display device; A key connected to an anode scan line between the microcontroller and the fluorescent display device, the A / D option circuit configured to sense an anode scan signal output to the fluorescent display device when the power is supplied and to apply to the microcontroller Scan circuit.