JPH0895442A - Image forming device - Google Patents

Abstract

PURPOSE: To detect the presence or absence of attachment attached to a main body without providing parts such as a switch and the like. CONSTITUTION: When the power source of a device A 501 is turned on in a state where a user detaches a device B 502 (that means, a connector 100 is detached) in order to perform some processing, a power source line 503 rises so as to try to supply power to the device B 502. However, a current (It) does not flow to a resistor 504, a power supply detecting device 505 detects the same voltage as that of the power source line 503 as Vs, and outputs a High signal, for instance, to a CPU. Therefore, the CPU performs ordinary operation by judging that the device B 502 is attached when the output signal from the device 505 is Low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a laser beam printer, and more particularly to an image forming apparatus having a detachable auxiliary device.

[0002]

2. Description of the Related Art In recent years, laser beam printers have been widely used as output devices for computers. In particular, low-density (for example, 300 dpi) laser beam printers are rapidly becoming popular due to their advantages of low price and compact size. As shown in FIG. 7, a laser beam printer 500 that prints at a print density of, for example, 300 dpi is connected to the printer engine unit 300 that actually prints on the photosensitive drum based on dot data, and is connected to the printer engine unit 300 and is connected to an external host. An image controller 200 that receives code data sent from the computer 100, generates page information composed of dot data based on the code data, and sequentially transmits the dot data to the printer engine unit 300; Engine control unit 30 in printer engine unit 300
Display unit 400 connected to the printer 1 and showing the operating status of the printer.
Consists of.

The host computer 100 loads a program by a floppy disk 600 having application software and functions as a word processor, for example.

Now, when a print instruction is issued from the host computer 100, the image controller 200 creates a printing bitmap according to the data of the host computer 100 and sends it to the printer engine unit 300.
Printer engine 302 in printer engine unit 300
Then, the non-designated laser is blinked according to the bit map to form a latent image, and the recording paper 70 is formed through the non-designated photoconductor.
Transfer the image to 0. Then, the image fixing unit 310 fixes the image on the recording paper 700, ejects the recording paper 700, and finishes a series of printing operations.

In carrying out these operations, as shown in FIG. 6, devices having various functions are connected to each other via a connector 551 or the like, and, for example, from device A501 (paper transport device) to device B502 (paper detection). Supply electric energy to the equipment.

[0006]

However, in the above-mentioned conventional example, the door switch 550 is provided to detect whether or not the accessory device is mounted, and the cost and mounting space for the door switch are required. Met.

Therefore, an object of the present invention is to provide an image forming apparatus which solves the above problems.

[0008]

According to a first aspect of the present invention, electric energy is supplied to a control means for performing control when an image is formed on a recording medium and a detachable auxiliary device related to the control. Means, a suppressing means for limiting the electric energy, a detecting means for detecting a voltage dropped by the suppressing means, and a means for judging whether or not the auxiliary device is attached by a detection signal of the detecting means. It is characterized by that.

According to a second aspect of the present invention, there is provided a second power source for supplying electricity to the accessory device, and a signal converting means for converting an analog detection signal from the voltage detecting means into a digital signal, and the judging means. According to the signal conversion result of the signal conversion means, the presence or absence of the accessory device and the abnormality of the second power supply are determined.

The invention according to claim 3 is characterized in that the detection means and the signal conversion means are integrated into one chip and incorporated in the control means.

According to a fourth aspect of the present invention, failure display means is provided, and the control means informs the failure display means that the operation of the apparatus main body is disabled when the signal of the detection means is determined to indicate that there is no auxiliary device. It is characterized by doing.

The invention according to claim 5 is characterized in that the control means detects the presence or absence of the accessory device by the detecting means when the accessory device is used when executing the energy-saving control method.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a drawing which best illustrates the features of this embodiment. In FIG. 1, reference numeral 501 is a main body apparatus A (paper conveying apparatus), and 502 is an auxiliary apparatus B attached to the main body apparatus A501. (Paper detection device), 503 is main device A
A power supply line for supplying electricity to 501 and the auxiliary device B502, a resistor 504 for suppressing electric energy supplied to the auxiliary device B502, and a voltage detection device 505 for detecting a voltage dropped by the resistor 504. 506 is device B
A sensor mounted within 502 having a light emitting diode 506A and a phototransistor 506B. Phototran JSI Uta 506B is power line 5
The light from the light emitting diode 506A emitted by the electric energy from 03 is received and a sensor signal is output. The device A 501 and the device B 502 are connected via the connector 100.

Now, when the user turns on the power of the device A501 in order to use this device, the power supply line 503 rises, and the electric energy is supplied to the device B through the resistor 504. Therefore, the voltage detection device 505 detects a voltage lower than a certain threshold voltage as Vs and outputs, for example, a Low signal to a central processing unit (CPU) (not shown) in the device 501.

On the other hand, the user uses the device B for some processing.
When 502 is removed (that is, the connector 100 is removed) and the device A 501 is powered on in that state, the power supply line 503 rises and tries to supply power to the device B. However, since the current It does not flow to the resistor 504, the power supply detection device 505 detects the same voltage as the power supply line 503 as Vs, and, for example, outputs a High signal to the CPU.
Output to.

Therefore, the CPU is the voltage detecting device 505.
If the output signal of is low, it is determined that the device B502 is attached, and normal operation is performed.

However, when the CPU receives the output signal of the voltage detection device 505 as High, the device B50
It is determined that the number 2 has been omitted, and a predetermined abnormality processing routine is executed. The sensor signal from the phototransistor 506B of the sensor 506 is the device A50.
1 is supplied to the CPU (Port 2).

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention. In FIG. 2, devices having the same functions as those in FIG. 1 are designated by the same reference numerals.

Reference numeral 507 is a second resistor that determines a predetermined voltage when the accessory device B502 is attached, and 508 is a signal conversion device that converts the signal of the voltage detection device 505 from analog to digital. Further, the power supply line 503 here is in the device A 501 and is in the voltage detection device 50.
It is assumed that the power supply line is different from that of the control device such as 5.

Now, when the power of the device A501 is turned on,
The power supply line 503 rises and supplies electric energy to the device B via the resistor 504. Thereby, the current I
A part of t flows into the second resistor 507 to reach a predetermined potential Vs, is detected by the voltage detection device 505, and is output to the signal conversion device 508. The signal converter 508 converts the input analog signal into, for example, a 2-bit digital signal “0”.
It is converted to 1 ″ and output to a central processing unit (CPU) not shown.

In addition, the user uses the device B for some processing.
When 502 is removed and the power of the device A 501 is turned on as it is, the power supply line 503 rises and tries to supply power to the device B. However, since the current It does not flow to the resistor 504, the power source detection device 505 is the device B5.
The voltage higher than the voltage when 02B is attached is Vs
And outputs it to the signal converter 508. The signal conversion device 508 converts the input analog signal into, for example, a 2-bit digital signal “11” and outputs it to the CPU.

On the other hand, due to some power failure, the power line 50
When 3 is not rising, the voltage V of the second resistor 507 is
Since s becomes 0, the signal conversion device 508 converts it into, for example, a 2-bit digital signal “00” and outputs it to the CPU.

Therefore, the CPU is the signal converter 508.
If the output signal of "01" is "01", it is determined that the device B502 is attached, and normal operation is performed.

However, if the CPU receives the output signal of the signal converter 508 as "11", the device B50
It is determined that the number 2 has been omitted, and a predetermined abnormality processing routine is executed.

Further, when the output signal of the signal converter 508 is "00", it is determined that the power supply line 503 is defective, and the inoperable processing routine is executed.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention. In FIG. 3, devices having the same functions as those in FIGS. 1 and 2 are designated by the same reference numerals.

It is assumed that the power supply line 503 here is in the device A501 and is constituted by a power supply line different from the control devices such as the voltage detection device 505, as in the second embodiment.

Further, the present embodiment is an example in which the voltage detection device 505 and the signal conversion device 508 shown in the second embodiment are incorporated in a control processing unit (CPU) not shown.

Now, when the power of the device A501 is turned on,
The power supply line 503 rises and supplies electric energy to the device B via the resistor 504. Thereby, the current I
A part of t flows into the second resistor 507 and reaches a predetermined potential Vs. This signal is directly taken into the CPU, and the analog signal input by the signal conversion processing unit inside the CPU is converted into, for example, a 2-bit digital signal "01".

Further, the device B is used by the user for some processing.
When 502 is removed and the power of the device A 501 is turned on as it is, the power supply line 503 rises and tries to supply power to the device B. However, since the current It does not flow to the resistor 504, a high voltage Vs similar to that of the power source run 503 is directly taken into the CPU, and the analog signal input by the signal conversion processing unit inside the CPU is converted into, for example, a 2-bit digital signal “11”. Convert to ".

On the other hand, due to some power failure, the power line 50
When 3 is not rising, the voltage Vs of the second resistor 507 is 0, so that the analog signal input by the signal conversion processing unit inside the CPU is converted into, for example, a 2-bit digital signal “00”. .

Therefore, the CPU outputs the converted signal of "0".
If it is 1 ", it is determined that the device B502 is attached, and normal operation is performed.

However, the converted signal is C as "11".
When the PU receives it, it is determined that the device B502 is disconnected, and the predetermined abnormality processing routine is executed.

Further, when the converted signal is "00", it is determined that the power supply line 503 is defective and the inoperable processing routine is executed.

(Fourth Embodiment) FIG. 4 shows a fourth embodiment of the present invention. In FIG. 4, devices having the same functions as those in FIGS. 1 and 2 are designated by the same reference numerals.

It is assumed that the power supply line 503 here is in the device A501 and is constituted by a power supply line different from the control device such as the voltage detection device 505, as in the second embodiment.

The present embodiment is an example in which a fan motor, for example, is selected as the electric component of the device B502 shown in the third embodiment.

In the figure, 509 is a drive circuit for driving the fan motor, and 510 is a fan motor.

An operation example is similar to that of the third embodiment.

(Fifth Embodiment) FIG. 5 is a fifth embodiment showing the feature of the present invention. In FIG. 5, devices having the same functions as those in FIGS. 1 and 2 are designated by the same reference numerals.

Reference numeral 511 denotes a processing unit (CPU) which controls the apparatus centering on the apparatus A501.

It is assumed that the power supply line 503 here is in the device A501 and is constituted by a power supply line different from the control device, as in the second embodiment.

In this embodiment, the determination of the mounting status of the device B502 and the check of the power supply line 503 are the same as those in the third embodiment.

Here, the CPU 511 is the display device 400.
When it is determined that the device B502 is not mounted, for example, when it is determined that the device B502 is not attached, the display device 40
It is output to 0 to notify the user who uses the image forming apparatus.

In the case where the CPU 511 is an auxiliary processing device, a signal indicating the same content is sent to the main CPU instead of the display device 400 to indicate that the device B 502 is not mounted and cannot operate. You may notify.

[0047]

As described above, according to the present invention, it is possible to detect the presence or absence of an accessory device mounted on the main body without providing a part such as a switch. Therefore, the cost of the switch and the mounting space can be omitted.

In the case of a CPU having an analog / digital conversion function, the power supply line can be monitored at the same time, so that the number of ports used can be saved.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of the present invention.

FIG. 2 is a schematic view showing a second embodiment of the present invention.

FIG. 3 is a schematic view showing a third embodiment of the present invention.

FIG. 4 is a schematic view showing a fourth embodiment of the present invention.

FIG. 5 is a schematic view showing a fifth embodiment of the present invention.

FIG. 6 is a diagram illustrating a conventional example.

FIG. 7 is another drawing for explaining a conventional example.

[Explanation of symbols]

 501 main body device A 502 auxiliary device B 504 resistor 505 voltage detection device 506 sensor

Claims (5)

[Claims] 1. A control means for performing control when forming an image on a recording medium, a means for supplying electric energy to a detachable auxiliary device related to the control, and a suppressing means for limiting the electric energy. An image forming apparatus comprising: a detecting unit that detects a voltage dropped by the suppressing unit; and a unit that determines whether or not the auxiliary device is attached by a detection signal of the detecting unit. 2. The device according to claim 1, further comprising: a second power supply that supplies electricity to the accessory device; and a signal conversion unit that converts an analog detection signal from the voltage detection unit into a digital signal. An image forming apparatus, wherein the presence / absence of the auxiliary device and the abnormality of the second power source are determined based on a signal conversion result of the signal conversion means. 3. The image forming apparatus according to claim 1, wherein the detection means and the signal conversion means are integrated into one chip and incorporated in the control means. 4. The fault display means according to claim 1 or 2, wherein the control means disables the operation of the apparatus main body when the signal of the detection means is judged to indicate that there is no auxiliary device, and causes the fault display means to operate. An image forming apparatus characterized by notifying. 5. The detection device according to claim 1, wherein the control means has an energy-saving control method of turning off the second power supply during standby, for example, when the instruction to use the accessory device is received. An image forming apparatus, characterized in that the presence or absence of an attached device is detected by means.