JP2009038606A - Image former - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image former which can ensure a communication quality corresponding to a change of a radio wave situation, etc. even in the case of a device having a large-sized casing. <P>SOLUTION: The image former comprises: a directional antenna 5 having a directivity; a nondirectional antenna 6 not having a directivity; and an antenna controller for controlling a directivity direction of the directional antenna. The directivity of the directional antenna 5 is simply switched to an optimal direction by control of the antenna controller. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus including a wireless communication unit.

In a wireless communication device such as a portable information terminal equipped with a wireless LAN function that has been spreading in recent years, it is an antenna having characteristics of uniform radiation characteristics and sensitivity of radio waves over the entire circumference of 360 °. In addition, omnidirectional antennas that can radiate radio waves and receive signals from any direction are used.
It is fixed and not used in many cases, and the installation location is not constant, and the location where the host access point (hereinafter referred to as “AP”) is installed differs depending on the usage situation. That there is a need to be able to transmit and receive even radio waves, that the speed of movement must be taken into consideration, and that communication while moving must be considered, and if it is omnidirectional, it is necessary to control even if the position changes This is because there is no radio wave transmission / reception.

By the way, not only wireless communication terminals that are carried around and used outdoors, but also image forming apparatuses such as MFPs (Multi Function Printers) that are devices used in offices have a wireless LAN terminal function.
An MFP or the like installed in such an office is often installed in a place where the radio wave environment is relatively poor due to the size of the casing. The antenna used for wireless communication is a omnidirectional antenna for both transmission and reception. However, since the omnidirectional antenna is not directional, there is an advantage that transmission and reception are possible regardless of how the antenna is installed. On the other hand, unnecessary radio waves are received. Further, there is a problem that reception performance is deteriorated due to fading such as radio wave reflection when the MFP is installed near a window because it is easily affected by reflected waves due to walls and the like.
In order to solve the problems caused by using such an omnidirectional antenna, there is a method using a directional antenna. In Patent Document 1, a directional antenna is used for a device fixed in an office or the like. Are disclosed.

A directional antenna is an antenna having radiation characteristics and sensitivity of radio waves only in a specific direction. For example, if the directivity is in the range of 0 ° to 5 °, radio waves are radiated only in this direction and reception sensitivity is also high. No. For this reason, it cannot transmit / receive with the communication apparatus in a 5 degree-360 degree direction, and there exists an advantage that it is not influenced by a reflected wave etc. That is, when the directional antenna is used, it is possible to solve the problem of radio wave interference such as fading due to the use of the omnidirectional antenna and to stabilize the communication quality.
JP 2005-45384 A

By the way, an image forming apparatus having a large casing such as an MFP usually hardly moves after installation, and since there are many fixed devices such as APs installed on a ceiling or a wall as a communication destination, it is usually directly. It is an environment where communication by waves is possible. Also, the absoluteity of an omnidirectional antenna is not high, and even if the AP position and radio wave conditions change due to changes in the office layout, etc., the directivity can be changed with respect to the AP by a directional antenna that can switch the directivity. In addition, it is possible to ensure communication quality.
However, in order to install a directional antenna, there is a problem in that it is necessary to check the directional direction with a dedicated measuring instrument.
Although the installation location is relatively fixed, it is necessary to review the antenna directivity when the radio wave conditions change due to changes in the office layout, etc. There was a problem that it was not easy to use.
SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can be used simply by switching the directivity of a directional antenna by itself.

In order to solve the above-described problem, an invention according to claim 1 is an image forming apparatus capable of wireless communication, wherein a directional antenna having directivity, an omnidirectional antenna having no directivity, and the directivity are provided. And an antenna control unit that controls the directivity direction of the antenna.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the directional antenna is a receiving antenna, and the omnidirectional antenna is a transmitting antenna.
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the antenna control unit measures and measures a radio wave intensity in order to determine a directivity direction of the directional antenna. Control is performed such that the directivity direction of the directional antenna is set in the direction in which the radio wave intensity is maximized.
According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the display unit that displays the radio wave intensity and the direction thereof, and the input unit that inputs the radio wave intensity and the direction displayed on the display unit. The antenna control unit performs control so as to set a directivity direction of the directional antenna based on an input result of the input unit.

  According to the configuration of the present invention, by including the antenna control unit that controls the directivity direction of the directional antenna, the directivity of the directional antenna can be easily switched, and stable communication quality can be achieved. Securement is possible.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described. FIG. 1 is a diagram illustrating an example of a configuration of an image forming apparatus according to an embodiment of the present invention.
In FIG. 1, an MFP 1 as an image forming apparatus according to the present embodiment includes a main body side control unit 2 on an image forming apparatus main body side, an internal interface (internal I / F) 3, and a wireless communication unit (wireless communication unit) 4. It has. The main body side control unit 2 includes a CPU (Central Processing Unit), a memory, and the like, and various controls control the entire MFP 1 based on a sequence of programs and the like.
The wireless communication unit 4 includes both an omnidirectional antenna 5 and a directional antenna 6 for use in wireless communication, and is connected to the main body side control unit 2 via an internal interface (internal I / F) 3. Operation is controlled.

FIG. 2 is a diagram for explaining in detail the configuration of the wireless communication unit 4 of the MFP 1 shown in FIG.
In FIG. 2, the wireless communication unit 4 includes an antenna switch (SW) 7, a directivity control unit 8, a wireless unit side control unit 9, and an antenna drive unit 10. The antenna SW7 is connected to the omnidirectional antenna 5 and connects the omnidirectional antenna 5 to the transmission side based on a switch control signal from the wireless unit side control unit 9. Note that the antenna SW7 is not necessarily provided. The directivity control unit 8 is connected to the antenna driving unit 10 and controls the driving of the antenna driving unit 10 based on the directivity switching control signal from the wireless unit side control unit 9 to control the directivity direction of the directivity antenna 6. Control. The wireless unit control unit 9 includes a CPU, a memory, and the like, and various controls control the directivity control unit 8 according to a sequence of programs and the like.
The wireless unit side control unit 9 includes a CPU, a memory, and the like, and various controls operate according to a sequence such as a program.
The antenna driving unit 10 drives the directional antenna 6 in the rotation direction based on the control of the directivity control unit 8. The configuration of the antenna driving unit 10 will be described later.
The MFP main body 1 is provided with an external control console 30 in addition to the main body side control unit 2 described above. The external control console 30 will also be described later.

In the MFP 1 of the present embodiment configured as described above, wireless communication is performed using the omnidirectional antenna 5 provided in the wireless communication unit 4 as a transmission antenna and the directional antenna 6 as a reception antenna. By using the directional antenna 6 as a receiving antenna in this way, unnecessary radio waves are not received, and it is difficult to be affected by reflected waves by walls or the like, so that reception performance is not deteriorated. .
The MFP 1 according to the present embodiment configured as described above is characterized in that the MPF 1 can automatically control the directivity direction of the directivity antenna 6.

FIG. 3 is a diagram illustrating the configuration of the antenna driving unit 10.
Here, a case where the directivity of the antenna is switched by a mechanical method as an example of the directional antenna 6 will be described as an example. The directional antenna 6 will be described by taking a parabolic antenna as an example.
The antenna driving unit 10 shown in FIG. 3 is directly connected to a pedestal 11 that fixes the directional antenna 6 to drive a directional antenna 6, and a pulse for driving the pedestal 11 to the stepping motor 12. It is comprised by the controller 13 which supplies a signal. The controller 13 controls the angle of the directional antenna 6 fixed to the pedestal 11 based on a control signal from the directivity control unit 8. For example, if the stepping motor 12 is a motor that can be controlled in units of 3 °, the rotation can be controlled in units of 3 ° by a pulse signal from the controller 13.
Therefore, by giving the controller 13 of the antenna driving unit 10 an angle for rotating the directional antenna 6 from the wireless unit side control unit 9 or the main body side control unit 2, the directional antenna 6 is directed to an arbitrary position and the directivity is set. It is possible to switch the direction.

In the present embodiment, the directivity control unit 8 is configured to be controllable by the wireless unit side control unit 9, and the wireless unit side control unit 9 is configured to be connected to the main body side control unit 2. The directivity of the antenna 6 can be controlled by either the wireless unit side control unit 9 or the main unit side control unit 2, and the directivity control unit 8 is controlled by one of the control units as necessary. Can be determined.
In this embodiment, the pedestal 11 and the stepping motor 12 are directly connected, but they may be connected via a mechanism such as a gear or a belt.
Further, in the present embodiment, the case where the directivity of the directional antenna 6 is changed by a mechanical method has been described as an example. However, a phased array antenna that can have directivity by an electric signal or signal processing, The same is possible with an adaptive array antenna.

FIG. 4 illustrates a case where the directivity direction switching control of the directional antenna is performed in the MPF 1 of the present embodiment.
As shown in FIG. 4, when the MFP 1 is installed on the wall 14 and there are an access point AP-A and an access point AP-B as access points, the directional antenna 6 is switched to the directivity α position. And the radio wave WA from the AP-A is received. At this time, in the MFP 1 of the present embodiment, the directivity in which the reception power value at the time of reception as the radio wave intensity is switched to the memory of the wireless unit side control unit 9 provided in the wireless communication unit 4 or the main body side control unit 2 provided in the MFP 1. It has a function to keep it with the direction.
Therefore, for example, in the case of the directional antenna 6 having a directivity of 3 °, if the directivity control unit 8 switches the directivity direction 120 times, the reception power value in all directions (360 ° all-round) is held. be able to. This function makes it possible to automatically obtain the reception power of the entire circumference.

Here, the received power value is taken as an example of the radio wave intensity, but data values such as bit error rate and transmission speed, which are other indicators of wireless communication quality, are acquired as radio wave intensity and stored in the memory. You may make it do.
Then, the received 360-degree reception power value data of the entire circumference is compared by the wireless unit side control unit 9 or the main body side control unit 2, and for example, the directivity is fixed by switching to the one having the largest reception power value. . This is because a larger reception power value is more likely to be stably connected with high communication quality.
For example, when the access point is only AP-A, the measured value of the reception power of the radio wave WA received when the directional antenna 6 is directed in the α direction is −30 dBm, and the directional antenna 6 is directed in the β direction. When the received power value of the radio wave WA ′ received at -5 is −50 dBm, the directional antenna 6 is fixed toward the α direction where the received power value is larger.

Further, when there is an access point AP-B in addition to the access point AP-A, the reception power of the radio wave WB from the access point AP-B received when the directional antenna 6 is directed in the δ direction is maximum. If so, the directional antenna 6 is fixed toward the δ direction.
Further, for example, when the reception power values of the radio wave WA and the radio wave WB are the same, the first selected directivity direction may be adopted, or the α direction and the radio wave WB from which the radio wave WA was received again are used. Measure the received power in the received δ direction, and if there is a difference in the received power, adopt the larger directivity direction, and if it is still the same, adopt the first selected directivity direction It may be.

FIG. 5 is a flowchart illustrating an example of processing for automatically acquiring the reception power value and switching the directivity direction in the MFP 1 of the present embodiment described so far.
In addition, the process demonstrated below is implement | achieved by the wireless unit side control part 9 or the main body side control part 2, or these cooperation. In this embodiment, the case where there is one access point is illustrated for easy understanding of the description.
In this case, first, the wireless unit side control unit 9 controls the antenna driving unit 10 via the directivity control unit 8 to rotate the directional antenna 6 by a predetermined angle, and the directional antenna 6 has a predetermined directivity. Set in the direction (S1).
Here, if the directional antenna 6 detects a radio wave (YES in S2), a radio wave reception power value is acquired (S3), and the reception power value and the directivity direction are associated with each other in the wireless unit side control unit 9. (S4). These operations are repeated until the detection and storage of the received power value and directivity direction of the 360-degree radio wave is completed while rotating the antenna at predetermined angles. When the 360 ° all-round search is completed (YES in S5), the main body side control unit 2 or the wireless unit side control unit 9 compares the values stored in the memory to obtain the maximum value (S6). Then, the directivity direction of the directivity antenna 6 is switched and fixed in the direction of the maximum value obtained.

In step S2, if radio waves cannot be detected (No in S2), it is determined whether or not there is a problem with reception settings. If there is no problem (No in S8), the directional antenna 6 is again set to a predetermined directivity. Set the direction.
In step S8, if there is a problem (NO in S8), an error display such as “Please check the wireless communication function” is displayed on the display unit described later (S9).
With the above operation, it is possible to automatically set the directivity by automatically selecting the direction with the maximum radio wave intensity (reception power) based on the collected data.
That is, even if the environment around the image forming apparatus changes, it becomes possible for the image forming apparatus to automatically adjust the directivity of the antenna to the radio wave direction that seems to be optimal.
In the MFP 1 of the present embodiment described so far, the direction in which the radio wave intensity is automatically selected and the directivity is automatically set has been described. However, the directivity can be set manually. is there.

FIG. 6 is a diagram showing a liquid crystal touch panel as an external control console 30 which is a man-machine I / F provided in the MFP 1.
The liquid crystal touch panel 10 includes a display unit 20 that provides information related to the MFP to an operator, and an input unit 21 for inputting commands to the main body side control unit 2 or the wireless unit side control unit 9.
The input unit 21 includes a “pie graph display” button 21-1, a “graph display” button 21-2, an “all-round scan” button 21-3, and a “directivity switching” button 21-4. , 21-2, the format of the graph to be displayed is switched. In addition, when an input operation is performed on the button 21-3, the entire circumference scan as described above is performed.
When the directivity direction is manually switched from the external control console 30, the received power value and the acquired data value are displayed on the display unit 20 as a graph or numerical value, and the operator sets an arbitrary directivity direction from this value. It is possible.
The pie chart 22 shown in the display unit 20 displays the state when the entire circumference is scanned as a graph. The area 23 in the pie chart 22 is the radio wave WA of the access point AP-A in FIG. 4, the area 24 is the radio wave WA ′ of the access point AP-A, the area 25 is the radio wave WB of the access point AP-B, and the area 26 is directed. The initial directivity direction of the directional antenna 6 is shown.

Further, by touching the “directivity switching” button 21-4, the directivity direction of the directivity antenna 6 is switched by the directivity control unit 8 via the main body side control unit 2.
When the directivity direction of the directional antenna 6 is switched, the position of the area 26 is also changed. For example, by adjusting the area 26 to the display position of the area 23, the directivity of the directional antenna 6 is changed to that of the access point AP-A. It becomes possible to match the radio wave WA.
As described above, when the MFP 1 of the present embodiment has a configuration in which the external control console 30 as a man-machine I / F, for example, a touch panel, a keyboard, or the like is connected, the external control console 30, Directivity can be directly controlled through the main body side control unit 2 and the wireless unit side control unit 9 to set an arbitrary directivity direction.
Further, by displaying the radio wave status on the display device of the MFP 1, it is possible to switch the antenna directivity to the optimum direction without any special knowledge from the operator.

In the present embodiment described so far, the wireless communication unit 4 is provided in the MFP 1, but the wireless communication unit 4 is connected via an external connection interface, and an arbitrary place outside the device, For example, it may be installed in a place with better radio conditions. If comprised in this way, it will become possible to install an antenna easily and it will become possible to ensure the stable communication quality.
In this embodiment, the omnidirectional antenna 5 can be configured in the same manner as in the past by configuring the directional antenna 6 to be dedicated for reception and directly connecting to the reception signal line. Therefore, for example, even in a conventional device that does not include the directivity control unit 8, the directivity antenna 6 is added as a reception antenna, the directivity antenna 6 is directly connected to the reception control line, and the directivity antenna 6 is manually switched. In this way, it is possible to add a reception-only antenna relatively easily.

1 is a diagram illustrating an example of a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating in detail a configuration of a wireless communication unit in the image forming apparatus of FIG. 1. The figure explaining the switching method of the mechanical system as an example of switching of a directivity direction. The figure which shows the basic control for acquiring the data of radio field intensity by switching a directivity switching antenna, and the fixed control of a directivity direction using acquisition data. The flowchart which shows an example of the process which acquires a reception power value automatically, and switches a directivity direction. FIG. 3 is a diagram illustrating a configuration of an external control console provided in the image forming apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 MFP, 2 Main body side control part, 3 Internal connection interface, 4 Wireless communication part, 5 Non-directional antenna, 6 Directional antenna, 7 Antenna switch, 8 Directional control part, 9 Wireless unit side control part, 10 Antenna Drive unit, 11 base, 12 striping motor, 14 walls, 18 controller, 20 display unit, 21 input unit, 22 pie chart, 23-26 area, 30 external control console

Claims (4)

In an image forming apparatus capable of wireless communication,
An image forming apparatus comprising: a directional antenna having directivity; an omnidirectional antenna having no directivity; and an antenna control unit that controls a directivity direction of the directional antenna.   2. The image forming apparatus according to claim 1, wherein the directional antenna is a receiving antenna, and the omnidirectional antenna is a transmitting antenna. The image forming apparatus according to claim 1, wherein
The antenna control unit measures radio field intensity to determine the directivity direction of the directional antenna, and controls to set the directivity direction of the directional antenna in a direction in which the measured radio field intensity is maximized. An image forming apparatus. The image forming apparatus according to claim 3.
A display unit for displaying the radio field intensity and its direction; and an input unit for inputting the radio field intensity and its direction displayed on the display unit;
The image forming apparatus according to claim 1, wherein the antenna control unit controls to set a directivity direction of the directivity antenna based on an input result of the input unit.

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