JP2003142995A - Sensor device with power saving display mode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor device which includes a second power saving display mode by which power consumption is saved while performing display with excellent visibility concerning only basic information whether the sensor is under operation or not or normally operated or not in addition to a power saving display mode to turn off a whole display unit. SOLUTION: In the second power saving display mode, only the on-state and off-state of a detection output are displayed through the use of segments in a part of digits d2 and d7 which are a part of the display unit 15. An output indicator 16 for displaying the on and off-states of the detection output in response to turning-on/off is arranged adjacently to the highest-order digit of the display unit 15. The off-state of the detection output is displayed by using the digit d7 which is nearer to the output indicator 16 of the display unit 15 and the on-state of the detection output is displayed by using the digit d2 which is far from the output indicator 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor device with a power saving display mode, and more particularly, to a sensor device having a display for displaying a detected value and the like in a power saving display mode for suppressing power consumption. Regarding improvement.

[0002]

2. Description of the Related Art As an example of such a sensor device, there is a photoelectric sensor (also referred to as a photoelectric switch) for detecting whether or not an object to be detected is present in a detection area. In addition, various industrial sensors such as a proximity sensor that detects an approach of an object from a change in magnetic field, a displacement sensor that uses a laser, and the like are included in the sensor device here.

Some sensor devices of this type are provided with a so-called 7-segment multi-digit indicator for numerically displaying a detection level or a threshold value (comparative set value).
Such indicators include LEDs (light emitting diodes), LC
It is composed of a D (liquid crystal display), a VFD (fluorescent display tube) or the like. For example, in a photoelectric sensor in which a sensor head unit including a light emitting unit and a light receiving unit and an amplifier unit (signal processing unit) are separated, the ON state and the OFF state of detection output are displayed in binary by turning on or off. In many cases, the output section (light emitting diode) and the 7-segment multi-digit display for numerically displaying the detection level and the threshold value are provided in the amplifier section.

A large number of sensor devices such as photoelectric sensors and proximity sensors are used in manufacturing lines of factories and the like. The amplifier units of these sensor devices are mounted densely on a standard-sized mounting rail called a DIN rail, for example, and are stored in a limited space such as a control panel or a control box.

The power consumed by the display unit of the sensor device is 1
Although it is relatively small with only one sensor device, when a large number of sensor devices are gathered as described above, the power consumption thereof cannot be ignored and the heat generation thereof becomes large. Therefore, some conventional sensor devices have a power saving display mode in which the power consumed for display is suppressed.

For example, there is a sensor device in which the power consumption is suppressed by lowering the display brightness in the power saving display mode than the display brightness in the normal display mode. However, in this case, the visibility of the display is lowered by lowering the display brightness, but the effect of reducing the power consumption is not so great.

In another sensor device, the display is turned off in the power saving display mode. In this case, although the effect of reducing the power consumption is great, it becomes impossible to obtain information from the display device whether or not it is operating or is operating normally.

In another sensor device, in the power-saving display mode, a part of the display of the 7-segment plural digits is erased, and only the remaining digits are displayed as numerical values or status display by simple characters. However, in this case, while the information obtained from the display is limited, the effect of reducing the power consumption is not so great. It is, so to speak, a half-power saving display mode.

[0009]

As described above, in the power saving display mode of the conventional sensor device, since the display is turned off, it is determined whether the display is operating or not operating normally. I couldn't get the basic information on the display. In the power-saving display mode of another sensor device, the brightness of the display is lowered or the display is performed using only some digits, but the effect of reducing the power consumption is not so great.

In view of the above-mentioned conventional problems, the present invention, in addition to the power saving display mode in which the display is completely turned off, determines whether or not the sensor is operating and whether it is operating normally. While displaying only basic information with good visibility,
An object of the present invention is to provide a sensor device having a second power saving display mode capable of significantly reducing power consumption.

[0011]

A sensor device with a power saving display mode according to the present invention is provided with a 7-segment multi-digit display for displaying a numerical value such as a detection level, and the display by the display is turned off. A sensor device having a first power-saving display mode, and a second power-saving display mode for displaying only an ON state and an OFF state of a detection output by using a part of a digit of a part of a display unit. It is characterized by having.

According to the second power-saving display mode as described above, basic information indicating whether or not the sensor is in operation or normally operating is displayed with good visibility using a display device. The power consumption required for display can be significantly reduced.

In the preferred embodiment, one of the two spaced apart digits of the indicator is used to indicate the on state of the sense output and the other digit is used to indicate the off state of the sense output. By doing so, the state in which the detection output of the sensor is switched between the ON state and the OFF state can be displayed on the display with good visibility.

In a further preferred embodiment, an output indicator for displaying the ON state and the OFF state of the detection output in correspondence with lighting and extinguishing is provided so as to be adjacent to the most significant digit or the least significant digit of the indicator. The off-state of the detection output is displayed using the digit closer to the output indicator and the on-state of the detection output is displayed using the digit farther from the output indicator.

Thus, when the detection output is in the off state, only a part of the digit of the digit closer to the output indicator of the display is turned on, and when the detection output is in the on state, the output indicator and the indicator are Some segments far from the output indicator light up. Therefore, whether the detection output is in the off state or the on state can be determined with good visibility by looking at the display device even from a distant place.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the external appearance of an amplifier section (sensor amplifier) of a photoelectric sensor, which is a type of sensor device according to an embodiment of the present invention. This sensor amplifier 1 is an example of an optical fiber type photoelectric sensor, and a thin rectangular parallelepiped case 10 is provided with connecting portions (insertion ports) 11 and 12 of a light projecting side optical fiber and a light receiving side optical fiber on the front side. ing. A cable connection portion (not shown) for power supply, detection signal output, and the like is provided on the back side.

The depression 13 on the lower surface is a mounting portion for mounting the sensor amplifier 1 on the DIN rail. Normally, a plurality of sensor amplifiers 1 are arranged side by side so as to be stacked and mounted on a DIN rail. Adjacent sensor amplifiers are mechanically and electrically connected to each other by a male connector 14 provided on one side surface and a female connector (not shown) provided on the other side surface.

On the upper surface of the sensor amplifier 1, 8 digits (4 digits x
A display 15 using the 7-segment LED of 2) and an output indicator (light emitting diode) 16 for binary-displaying the ON state and the OFF state of the detection output by turning on or off are provided. Further, push button switches 17 to 20 used for setting a threshold value for detection determination, switching operation modes and display modes, and the like are provided. The push button switch 18 is a swing type up / down push button switch.

FIG. 2 is a block diagram showing the circuit configuration of the photoelectric sensor according to the embodiment of the present invention. In this example, the light projecting side optical fiber 3 to which the light projecting head 3a is attached and the light receiving side optical fiber 4 to which the light receiving head 4a is attached are connected to (the optical fiber connecting portions 11 and 12 of) the sensor amplifier 1 and transmitted. Type photoelectric sensor. In the sensor amplifier 1, a light emitting element (for example, a light emitting diode) 22 connected to the base end side of the light projecting side optical fiber 3 and a light receiving element (for example a photodiode) 24 connected to the base end side of the light receiving side optical fiber 4 are provided. Is built in.

The light emitted from the light emitting element 22 propagates through the light projecting side optical fiber 3 and is projected from its tip (light projecting head 3a) as shown by a broken line (to spread at an angle of about 60 degrees). The light is incident on the light receiving side optical fiber 4 from the light receiving head 4a provided at the opposite position, propagates through the light receiving side optical fiber 4, and reaches the light receiving element 24. When the detection target WK blocks the optical path LB from the light projection head 3a to the light reception head 4a, the amount of light received by the light receiving element 24 decreases.
The presence or absence of K can be detected.

When the reflection type photoelectric sensor is constructed, the light projected from the light projecting head 3a is projected so that the light projected from the light projecting head 3a is reflected by the object WK to be detected and enters the light receiving side optical fiber 4 from the light receiving head 4a. The positions and directions of the head 3a and the light receiving head 4a are set. Alternatively, a head unit in which the light projecting head 3a and the light receiving head 4a are integrated is used. There are various types of photoelectric sensors. For example, in a so-called amplifier-separated type, a light emitting element and a light receiving element are built in the head portion, and the head portion and the sensor amplifier are connected by an electric cable instead of an optical fiber.

In FIG. 2, the sensor amplifier 1 includes a drive circuit 23 for the light emitting element 22 and a processing unit (microprocessor) 28 for controlling the drive circuit 23. Further, an amplifier circuit 25 for amplifying an electric signal corresponding to the amount of received light output from the light receiving element 24, and an A / D converter 26 for converting the output voltage of the amplifier circuit 25 into a digital value are built-in, and
The digital value obtained from the D converter 26 is input to the processing unit 28. The processing unit 28 compares the input digital value with a threshold value described later, and the result is detected by the detection target object W.
A binary signal indicating the presence or absence of K is output from the output circuit 27 to an external device. In the photoelectric sensor of this embodiment, 12
Bit A / D converter 26 is used, 0-4095
Outputs a (decimal) digital value.

Further, the display circuit 30 corresponding to the above-mentioned display 15 and the output indicator 16, the push button switches 17 to.
A push button switch circuit 31 corresponding to 20 and a connecting circuit 32 corresponding to connecting connectors (male connector 14 and female connector) are also incorporated in the sensor amplifier 1, and the processing unit 28 also controls these. In FIG. 2, the flow of data relating to the amount of received light and the detected value of the input / output signals of the processing unit 28 is shown by solid arrows, and the other control signals are shown by broken arrows.

FIG. 3 shows an example of a state in which a plurality of sensor amplifiers and communication end units are attached to a DIN rail and are connected so as to overlap each other. In this example, five sensor amplifiers 1 and one communication end unit 2 are connected,
It is fixed to the DIN rail 3. The sensor amplifier 1 shown in FIG. 3 is in a state in which the upper surface of the sensor amplifier 1 shown in FIG. 1 is covered with a dust-proof cover made of transparent plastic.

The communication end unit 2 has a function of mechanically holding the ends of a plurality of connected sensor amplifiers 1 and a communication function with a management device (for example, a personal computer). A female connector is provided on the side surface of the communication end unit 2 similarly to the side surface of the sensor amplifier 1, and is mechanically and electrically connected to the sensor amplifier 1. The four sensor amplifiers 1 other than the sensor amplifiers adjacent to (directly connected to) the communication end unit 2 are also bus-connected to the communication end unit 2 via the adjacent sensor amplifiers 1. The five sensor amplifiers 1 can individually exchange signals with the communication end unit 2.

When the cover 21 of the communication connector provided on the upper surface of the communication end unit 2 is opened, the communication connector connected to the internal circuit is exposed so that the communication cable can be connected. Communication end unit 2
Communicates with a personal computer by RS-232C serial communication, for example. That is, the personal computer accesses each of the plurality of sensor amplifiers 1 online via the communication end unit 2,
The operation mode and set value of each sensor amplifier 1 can be monitored or the setting can be changed.

FIG. 4 is a top view of the sensor amplifier 1 shown in FIG. Display 15 provided in the sensor amplifier 1
Is an 8-digit 7-segment display, which has a 4-digit first display section 15a and a 4-digit second display section 15b.
Are arranged in a line. For example, during the detection operation,
It is possible to use such a mode that the first display portion 15a (lower 4 digits) displays the detected value in decimal number and the second display portion 15b (upper 4 digits) shows the threshold value (set value) in decimal number. . Alternatively, as shown in FIG. 5, the detected value or threshold value is displayed in decimal on the first display unit 15a, and the detected value or threshold value is displayed as a bar using a partial segment of each digit on the second display unit 15b. It is possible to use it in the form of a graph.

Further, the photoelectric sensor of this embodiment is provided with a high precision mode in which the detected value and the threshold value are displayed in decimal with 5 digits in addition to the normal mode in which the maximum number of digits is 4 and displayed in decimal. . When the detection value (or threshold value) is displayed in the high precision mode, as shown in FIG. 6, the first display unit 15a
And the second display portion 15b are used (connected) to perform a 5-digit decimal display. Of course, by connecting the first display unit 15a and the second display unit 15b, it is possible to display a decimal number of up to 8 digits.

Next, a usage example of the push button switches 17 to 20 will be briefly described. Each push button switch is also used for a plurality of functions, and the following usage examples are some of the functions.

First, when setting the threshold value, the push button switch 17 (hereinafter referred to as the set SW) and the push button switch 18 are set.
(Hereinafter referred to as an up-down SW) is used. For example, in FIG. 2, the detection target object WK is arranged so as to block the optical path LB from the light projecting head 3a to the light receiving head 4a, the set SW 17 is pressed, and then the detection target object WK is moved to the optical path LB.
The set SW17 is pressed again in the state of being removed from. As a result, a detection value corresponding to the amount of received light when the detection target WK is blocking the optical path LB (for example, 2000) and a detection value corresponding to the amount of received light when not blocked (for example, 4000).
An intermediate value between and (for example, 3000) is automatically set as the threshold value.

At this time, the set value of the threshold value is displayed on the display unit 15.
Is displayed in. In the normal mode, four digits are displayed on either one of the first display section 15a and the second display section 15b. Then, the up / down SW 18 can be used to increase / decrease the set value of the threshold value.

Next, to set the operation mode, the push button switch 19 (hereinafter referred to as mode SW) and the up / down switch are set.
18 is used. If the mode SW 19 is kept pressed for a certain time (for example, 2 seconds) or more, the setting of the operation mode can be changed, and the operation mode can be sequentially selected by using the up / down SW 18. At this time, the selected operation mode is displayed on the display unit 15 in a simplified alphabet. For example, as shown in FIG. 7, "fine",
Six types of operation modes of “turbo”, “super turbo”, “ultra turbo”, “high speed”, and “super fine” are changed in both forward and reverse directions by pressing the up / down SW 18.

It should be noted that the six types of operation modes are suitable for the light projection amount (light emitting element 22) depending on the size and distance of the object to be detected.
Drive pulse width), sensitivity (amplification degree of the amplifier circuit 25), and other circuit conditions are optimized. For example,
The "fine" mode corresponds to the above-mentioned normal mode, and is optimized for a distance of about 100 mm from the projection head 3a to the detection target WK. "Turbo" mode is 200m
m, "Super Turbo" mode is optimized to 300 mm, and "Ultra Turbo" is optimized to 400 mm.
The "high speed" mode is an operation mode in which the response speed is increased so that the detection target WK that crosses the optical path LB relatively quickly can be detected.

The "super fine" mode corresponds to the above-described high precision mode, and in this mode, the amount of light projected or the sensitivity (amplification factor) is "fine" mode (normal mode).
By lowering it further, even when the distance from the projection head 3a to the detection object WK is further shortened than in the "fine" mode, the amplification circuit 25 or the A / D converter 26 is less likely to be saturated. By doing so, the spread of the projected spot diameter is suppressed, and the detection target object WK is small (or thin).
Even in this case, it is possible to detect accurately. However, since the amount of received light decreases, the processing unit 28 executes processing to compensate for the decrease in the amount of received light, which will be described later.

The photoelectric sensor of the present embodiment is different from the above operation mode in that it differentiates a change in the detected value and outputs a rising edge or falling edge detection signal, or delays from a rising edge or a falling edge. Various modes are provided, such as a timer mode in which a detection signal is output after a time (which can be set). Further, a plurality of display modes are provided for the display unit 15. The mode switching can also be changed by combining the order of pressing the push button switches 17 to 20 and the pressing method (for example, pressing for 2 seconds or more, pressing twice).

Next, the display mode during the detection operation of the photoelectric sensor will be described. FIG. 8 is a diagram showing display examples in the normal display mode and the power saving display mode. FIG. 8A shows
It is a display example in the normal display mode, and it is displayed on the right side 4
The detected value “1234” is displayed in decimal on the first display portion 15a of the digit, and the threshold value “300” is displayed in decimal on the second display portion 15b of four digits on the right side. At this time, since the detection value is larger than the threshold value, the detection output is turned on and the output indicator 16 is lit.

The photoelectric sensor of this embodiment is provided with the first and second power-saving display modes in addition to the normal display mode as the display mode during the detection operation. The display modes can be sequentially switched using, for example, the push button switch 20.

FIG. 8B shows the first power-saving display mode. In this display mode, the display unit 15 is in the all-off state. Then, the output indicator 16 is turned on or off depending on the magnitude relation between the detected value and the threshold value. In this display mode, the display 15 is completely turned off, so the power consumption required for display is minimized. However, whether or not the voltage is supplied from the power supply to the photoelectric sensor, whether or not the photoelectric sensor is operating, or normal operation is possible. Information on whether or not it is operating
You can't get from 5. When the detected value is larger than the threshold value, the output indicator 16 is lit, so that it can be known that the photoelectric sensor is operating, but it cannot be determined whether or not the photoelectric sensor is operating normally. When the detected value is smaller than the threshold value, the output indicator 16 is also turned off, and it is impossible to judge whether the photoelectric sensor is in operation.

FIGS. 8C and 8D show the second power saving display mode. FIG. 8C shows the case where the detected value is larger than the threshold value, the output indicator 16 lights up, and "o" is displayed by the lower four segments of the second digit d2 of the display unit 15. (“Output on” display). Further, FIG. 8D shows the case where the detected value is smaller than the threshold value, the output indicator 16 is turned off, and “o” is displayed by the lower four segments of the seventh digit d7 of the display unit 15. Has been done.

As described above, in the second power-saving display mode, only the ON state and the OFF state of the detection output are displayed by using some segments of some digits of the display unit.
Although the power consumption does not drop to the full-off state shown in (b), the power consumption can be significantly reduced compared to the normal display mode of FIG. 8 (a). Moreover, since the ON state and the OFF state of the detection output are displayed at different positions (digits), only whether or not the voltage is supplied from the power supply to the photoelectric sensor and whether or not the photoelectric sensor is operating. Instead, it is possible to determine from the display unit 15 whether or not it is operating normally.

Further, when the detection output is in the off state,
As shown in (d), the output indicator 1 of the display 15
When a segment of the digit closer to 6 is lit and the detection output is in the ON state, as shown in FIG. 8C, the output indicator 16 is lit and the one farther from the output indicator 16 of the display 15 is located. A part of the segment lights up.
Therefore, it is possible to determine whether the detection output of the photoelectric sensor is in the off state or the on state from the display of the display 15 with good visibility even from a distant place.

In the second power-saving display mode in the above-described embodiment, the second digit d2 and the seventh digit d7 of the display 15 are made to correspond to the ON state and the OFF state of the detection output, and their partial segments. Is turned on, but other digits may be used. For example, the first digit and the eighth digit may be used in correspondence with the ON state and the OFF state of the detection output.
In short, one of the two digits of the display 15 which are separated from each other is used to display the ON state of the detection output, and the other digit is used to display the OFF state of the detection output. Then, preferably, the off-state of the detection output is displayed using the digit closer to the output indicator 16, and the output indicator 1
The digit farther from 6 is used to indicate the ON state of the detection output.

In the second power-saving display mode in the above embodiment, "o" is displayed using the lower four segments of the second digit d2 and the seventh digit d7 of the display 15. Alternatively, the upper four segments may be used to display "o", and any character or symbol other than "o" may be used as any one or more segments (part of seven segments). You may display it.

In addition, one digit of the display 15 (for example, the second digit)
The segments (one or more) having different digits d2) may be displayed in correspondence with the ON state and the OFF state of the detection output. In short, in the second power-saving display mode, the effect of the present invention can be obtained by displaying only the ON state and the OFF state of the detection output by using some segments of some digits of the display unit 15.

Besides, the present invention can be implemented in various forms. For example, the number of digits and the configuration of the display unit 15 and the positional relationship with the output indicator 16 are not limited to the illustrated example. Further, the present invention is not limited to the photoelectric sensor,
It can be applied to various industrial sensor devices such as proximity sensors and displacement sensors. Furthermore, the present invention can be applied not only to a sensor device of a type in which the sensor head unit and the amplifier unit are separated but also to an integrated sensor device.

[0047]

As described above, in the sensor device with the power saving display mode of the present invention, in addition to the first power saving display mode in which the display is completely turned off, some digits of the display are displayed. A second power-saving display mode that displays only the ON state and the OFF state of the detection output by using some segments of
According to the second power saving display mode, basic information indicating whether the sensor is supplied with a voltage from the power supply, whether the sensor is operating, or whether the sensor is normally operating is displayed on the display unit. While it can be obtained with high visibility, the power consumption required for display can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of a sensor amplifier of a photoelectric sensor according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a photoelectric sensor according to an embodiment of the present invention.

FIG. 3 is a perspective view showing an example of a state in which a plurality of sensor amplifiers and a communication end unit are attached to a DIN rail and are connected so as to overlap each other.

FIG. 4 is a top view of the sensor amplifier shown in FIG.

FIG. 5 is a diagram showing a display example of a display device.

FIG. 6 is a diagram showing another display example of the display device.

FIG. 7 is a diagram showing a display transition example of operation modes.

FIG. 8 is a diagram showing display examples in a normal display mode and a power saving display mode.

[Explanation of symbols]

15 Indicator 16 Output indicator The digit farther from the output indicator of the d2 display d7 Digit closer to the output indicator of the display

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Claims (3)

[Claims] 1. A sensor device provided with a 7-segment multi-digit display for numerically displaying a detection level and the like, and having a first power-saving display mode for turning off all the display by said display. A power-saving display mode is provided, which includes a second power-saving display mode for displaying only an ON state and an OFF state of the detection output by using a segment of a part of a digit of the display. Sensor device. 2. The on-state of the detection output is displayed using one of two digits of the display, which are separated from each other, and
The sensor device with a power saving display mode according to claim 1, wherein the off state of the detection output is displayed using the other digit. 3. An output indicator for displaying an ON state and an OFF state of the detection output in correspondence with lighting and extinguishing is provided so as to be adjacent to the most significant digit or the least significant digit of the display unit. 3. The digit closer to the output indicator is used to display the off state of the detection output, and the digit farther from the output indicator is used to display the on state of the detection output. A sensor device with the described power saving display mode.