JP6833382B2 - Open / close judgment device and image forming device - Google Patents

Description

The present invention relates to an open / close determination device and an image forming apparatus, and more particularly to an image forming apparatus having a door for accessing the inside of the image forming apparatus and the opening / closing determination apparatus thereof.

Conventionally, the image forming apparatus is provided with a door 19 for accessing the inside of the image forming apparatus, as shown in FIG. 7, for example (see, for example, Patent Document 1). Such an image forming apparatus is provided with a switch 25 for detecting whether the door 19 is in the open state or the closed state. The switch 25 is in the connected state as shown in FIG. 8A, and the CPU 100 detects the on or off of the switch 25 based on the voltage Vad to change the closed state or the open state of the door 19. Deciding. The image forming apparatus has a normal mode and a power saving mode, and when shifting from the normal mode to the power saving mode, the output voltage Vcc of the low voltage power supply 110 is lowered. The CPU 100 determines the open / closed state of the door 19 in each mode by using the threshold voltage Vth2 in the normal mode and by using the threshold voltage Vth1 in the power saving mode (see FIG. 8B). Further, as shown in FIG. 8A, capacitors Ca and Cb are provided at both ends of the switch 25 for the purpose of stabilizing the voltage. Therefore, when the mode is changed from the normal mode to the power saving mode, the voltage Vad stabilizes after the time required for discharging the capacitors Ca and Cb has elapsed (see FIG. 9A). The details of FIGS. 7 to 9 will be described later.

Japanese Unexamined Patent Publication No. 2004-138893

However, the conventional open / close detection method for the door 19 has the following problems. When the output voltage Vcc of the low voltage power supply 110 drops after shifting from the normal mode to the power saving mode, the voltage Vad also drops. Here, as shown in FIG. 9B, when the door 19 is opened and closed between the time t8 and the time t9 while the voltage Vad is decreasing, for example, in a short time from the time ta to the time tb, the following become that way. That is, when the door 19 is opened and closed in a short time from the time ta to the time tb, the voltage Vb of the other end Sd does not instantly become zero because the capacitor Cb is connected to the other end Sd of the switch 25. Therefore, the voltage Vad does not become equal to or less than the threshold voltage Vth1 in the power saving mode, and the CPU 100 cannot detect that the door 19 is in the open state.

On the other hand, when the door 19 is opened, the contact 15 and the contact arm 16 mechanically interlocked with the door 19 shown in FIG. 7 rotate, and the contact 15 is separated from the non-volatile memory 17. Therefore, the information output by the CPU 100 when trying to write to the non-volatile memory 17 between the time ta and the time tb may not be accurately written to the non-volatile memory 17. Further, since the CPU 100 cannot detect the open state of the door 19, there is a possibility that the recovery process of the information to be written to the non-volatile memory 17 between the time ta and the time tb cannot be performed. Therefore, even when the output voltage Vcc of the low-voltage power supply 110 changes, it is required to more accurately detect the open / closed state of the door 19.

The present invention has been made under such circumstances, and an object of the present invention is to more accurately detect the opening and closing of a door even when the output voltage of a power source changes.

In order to solve the above-mentioned problems, the present invention includes the following configurations.

(1) An output means that converts an AC voltage and outputs a DC voltage and the output means are connected to one end, and the DC voltage output by the output means is supplied to the load in the closed state and is in the open state. In addition to the switch means, which cuts off the supply to the load at the time, the capacitor connected to the other end of the switch means, and the switch means during the period when the DC voltage output from the output means is changing. If the decrease amount within a predetermined time of the voltage at the end is larger than a predetermined amount, said switching means closing determination apparatus characterized by comprising: a determination means for determining that is opened.
(2) An output means that converts an AC voltage and outputs a DC voltage and the output means are connected to one end, and the DC voltage output by the output means is supplied to the load in the closed state and is in the open state. A switch means that cuts off the supply to the load at the time, a capacitor connected to the other end of the switch means, and an opening / closing member for accessing the inside of the image forming apparatus, and the switch is in the open state. The opening / closing member whose means is also in the open state and the switch means is also in the closed state when the means is closed, and the voltage at the other end of the switch means during the period when the DC voltage output from the output means is changing. An image forming apparatus comprising: a determination means for determining that the opening / closing member is in an open state when the amount of decrease within a predetermined time becomes larger than a predetermined amount.
(3) An output means that converts an AC voltage and outputs a DC voltage and the output means are connected to one end, and the DC voltage output by the output means is supplied to the load in the closed state and is in the open state. In addition to the switch means that cuts off the supply to the load at the time, the capacitor connected to the other end of the switch means, the first detection means that detects the voltage at the other end of the switch means, and the switch means. Depending on the second detecting means for detecting the voltage at the end and the DC voltage output from the output means, the first detecting means detects the voltage at the other end, or the second detecting means. Judgment as to whether the opening / closing member is in the open state or the closed state based on the switching means for switching whether to detect the voltage at the other end and the result detected by the first detection means or the second detection means. An opening / closing determination device characterized by means and provision.
(4) An output means that converts an AC voltage and outputs a DC voltage and the output means are connected to one end, and the DC voltage output by the output means is supplied to the load in the closed state and is in the open state. A switch means that cuts off the supply to the load at the time of, a capacitor connected to the other end of the switch means, and an opening / closing member for accessing the inside of the image forming apparatus, and the switch is in the open state. The opening / closing member whose means is also in the open state and the switch means is also in the closed state when the switch means is closed, the first detecting means for detecting the voltage at the other end of the switch means, and the voltage at the other end of the switch means. Depending on the second detecting means to be detected and the DC voltage output from the output means, the first detecting means detects the voltage at the other end, or the second detecting means detects the other end. A switching means for switching whether or not to detect the voltage of the above, and a determining means for determining whether the opening / closing member is in the open state or the closed state based on the result detected by the first detection means or the second detection means. An image forming apparatus comprising the above.

According to the present invention, it is possible to more accurately detect the opening and closing of the door even when the output voltage of the power supply changes.

The figure explaining the door open / close detection control of Example 1. The figure explaining the door open / close detection control of Example 1. The figure which shows the open / closed state of the door of the image forming apparatus of Example 1. The figure explaining the door open / close detection control of Example 2. The figure explaining the door open / close detection control of Example 3. The figure explaining the door open / close detection control of Example 3. The figure which shows the open / closed state of the door of the image forming apparatus of a conventional example. The figure explaining the connection state of the switch of the conventional example, the figure explaining the door open / close detection control The figure explaining the door open / close detection control of the conventional example The figure explaining the door open / close detection control of Example 4. The figure explaining the door open / close detection control of Example 4. The figure explaining the door open / close detection control of Example 4. The figure explaining the door open / close detection control of Example 5. Flow chart showing the operation of the fifth embodiment

[Image forming device]
FIG. 7 is a diagram showing an image forming apparatus. The image forming apparatus includes a door 19 for accessing the inside of the image forming apparatus. FIG. 7A is a diagram showing an image forming apparatus in a state where the door 19 is closed. The paper 1 which is a recording material is fed into the transport path by the rotation of the pickup roller 2, and is conveyed by the transport rollers 3 and 4 to the nip portion formed by the transfer roller 10 and the photosensitive drum 5. The photosensitive drum 5 is housed together with a charging roller 6, a developing sleeve 7, and toner 8 in a cartridge 9 which is a removable image forming portion. The photosensitive drum 5 is charged by the charging roller 6, and the laser scanner 14 irradiates the photosensitive drum 5 with light 13 to form a latent image on the surface. The latent image formed on the photosensitive drum 5 is developed by the developing sleeve 7, and a toner image is formed on the photosensitive drum 5. The toner image is transferred from the nip portion of the transfer roller 10 and the photosensitive drum 5, the paper 1 is heated and pressurized by the fixing roller 11 and the pressure roller 12, and is discharged to the outside of the image forming apparatus.

The cartridge 9 is provided with a non-volatile memory 17. Information about the cartridge 9 such as the remaining amount of toner 8 is recorded in the non-volatile memory 17. Information is written to the non-volatile memory 17 via the contact 15 and the contact arm 16. That is, when the contact 15 comes into contact with a predetermined position of the non-volatile memory 17, information is written to the non-volatile memory 17. Further, the image forming apparatus is provided with a switch 25 which is a switch means for detecting an open state (hereinafter, referred to as an open state) and a closed state (hereinafter, referred to as a closed state) of the door 19. The switch 25 is, for example, an interlock switch, which is turned off when the door 19 is open and turned on when the door 19 is closed.

FIG. 7B is a diagram showing an image forming apparatus with the door 19 open. By opening the door 19 as shown in FIG. 7B, the switch 25 is switched from on to off. Further, the contact 15 and the contact arm 16 that are mechanically interlocked with the opening / closing operation of the door 19 rotate in conjunction with the transition from the closed state to the open state of the door 19, and the contact 15 is the non-volatile memory 17. It is separated from a predetermined position and becomes a non-contact state.

[Electrical connection status of switch]
The electrical connection of the switch 25 will be described with reference to FIG. 8A. The output voltage Vcc of the low-voltage power supply 110, which is an output means, is connected to one end Su of the switch 25. The low voltage power supply 110 converts the AC voltage Vac into a DC voltage and outputs the output voltage Vcc to the load via the switch 25. The switch 25 supplies power from the low-voltage power supply 110 to the load in a state of being connected when the door 19 is closed (hereinafter, this state is referred to as on). On the other hand, the switch 25 cuts off the supply of electric power from the low-voltage power supply 110 to the load in a state of being disconnected when the door 19 is in the open state (hereinafter, this state is referred to as off). A motor M is connected to the other end Sd of the switch 25. The voltage of the other end Sd of the switch 25 is Vb.

The motor M is a motor that drives the paper 1 to be conveyed, and corresponds to a load to which electric power is supplied from the low-voltage power supply 110. When the door 19 is opened, the switch 25 is turned off, and the power supply from the low voltage power supply 110 to the motor M via the switch 25 is cut off. Further, a resistor Ra and a resistor Rb are connected to the other end Sd of the switch 25. The resistor Ra and the resistor Rb divide the voltage Vb of the other end Sd of the switch 25. The voltage Vad divided by the resistors Ra and Rb is output to the analog-digital (hereinafter referred to as A / D) conversion input terminal of the CPU 100, which is a logical operation element. The CPU 100 executes various programs stored in the ROM 100a and performs various controls while using the RAM 100b as a work area. The CPU 100 determines whether the door 19 is in the open state or the closed state based on the input voltage Vad. Further, a capacitor Ca and a capacitor Cb are connected to both ends of the switch 25 for the purpose of stabilizing the voltage. Specifically, a capacitor Ca is connected to one end Su of the switch 25, and a capacitor Cb is connected to the other end Sd of the switch 25.

[Door open / close detection method]
(In normal mode)
FIG. 8B shows a method of detecting the opening / closing of the door 19. FIG. 8B is a graph showing time (t) on the horizontal axis and voltage Vad on the vertical axis. During the period from time t1 to time t2, the door 19 is closed and the switch 25 is on. At this time, the output voltage Vcc is the output voltage (for example, 24V) in the normal mode in which the image forming apparatus is supplying the power required for performing the image forming operation, and the voltage Vad is It becomes Vil2. The CPU 100 compares the preset threshold voltage Vth2 (indicated by the broken line in FIG. 8B) with the voltage Vad in the normal mode, and determines the open / closed state of the door 19. Here, when the CPU 100 determines that the voltage Vad is larger than the threshold voltage Vth2 (Vth2 <Vad), the CPU 100 determines that the door 19 is in the closed state. On the other hand, when the CPU 100 determines that the voltage Vad is equal to or less than the threshold voltage Vth2 (Vad ≦ Vth2), the CPU 100 determines that the door 19 is in the open state. Therefore, in the period from time t1 to time t2 in FIG. 8B, the voltage Vad (= Vil2) is larger than the threshold voltage Vth2 (Vil2> Vth2), and the CPU 100 determines that the door 19 is in the closed state. .. When the door 19 is opened at time t2, the switch 25 is turned off, the voltage Vad is lowered, and the threshold voltage Vth2 or less is set at time t3. Therefore, the CPU 100 determines that the door 19 is in the open state after the time t3.

(In power saving mode)
By the way, the image forming apparatus is known to have a configuration in which the output voltage Vcc of the low voltage power supply 110 is lowered as a power saving mode during standby. The CPU 100 outputs a power saving signal LVM to the low voltage power supply 110 from the LVM terminal connected to the low voltage power supply 110. When the power saving signal LVM is input from the CPU 100, the low voltage power supply 110 lowers the output voltage Vcc to the output voltage (for example, 12V) of the preset power saving mode.

The door open / close detection control in the power saving mode will be described. During the period from time t4 to time t5 in FIG. 8B, the door 19 is in the closed state. At this time, the output voltage Vcc is the output voltage (for example, 12V) in the power saving mode, and the voltage Vad is Vil1. The CPU 100 compares the preset threshold voltage Vth1 (indicated by the broken line in FIG. 8B) with the voltage Vad in the power saving mode, and determines the open / closed state of the door 19. Here, when the CPU 100 determines that the voltage Vad is larger than the threshold voltage Vth1 (Vth1 <Vad), the CPU 100 determines that the door 19 is in the closed state. On the other hand, when the CPU 100 determines that the voltage Vad is equal to or less than the threshold voltage Vth1 (Vad ≦ Vth1), the CPU 100 determines that the door 19 is in the open state. Therefore, in the period from time t4 to time t5 in FIG. 8B, the voltage Vad (= Vil1) is larger than the threshold voltage Vth1 (Vil1> Vth1), and the CPU 100 determines that the door 19 is in the closed state. .. When the door 19 is opened at time t5, the switch 25 is turned off, the voltage Vad is lowered, and the threshold voltage Vth1 or less is set at time t6. Therefore, the CPU 100 determines that the door 19 is in the open state after the time t6.

[Door open / close detection when shifting from normal mode to power saving mode]
FIG. 9A is a diagram illustrating opening / closing detection control of the door 19 when the mode of the image forming apparatus is switched from the normal mode to the power saving mode. FIG. 9A is a graph showing time (t) on the horizontal axis and voltage Vad on the vertical axis. It should be noted that duplicate description of the same value or the like as described in FIG. 8B will be omitted. During the period from time t7 to time t8, the image forming apparatus is operating in the normal mode. In this period, the threshold voltage used to detect the open / closed state of the door 19 is Vth2. Here, the CPU 100 outputs the power saving signal LVM to the low voltage power supply 110, and switches from the normal mode to the power saving mode at time t8. The CPU 100 controls the output voltage Vcc of the low voltage power supply 110 to be switched from 24V to 12V, and also switches the threshold voltage from Vth2 to Vth1 (indicated by a broken line in FIG. 9A).

As shown in FIG. 8A, a capacitor Ca and a capacitor Cb are connected to both ends of the switch 25 for the purpose of stabilizing the voltage. Therefore, even if the normal mode is switched to the power saving mode at time t8, the output voltage Vcc of the low voltage power supply 110 is not immediately switched, and the voltage Vad is not immediately switched. The voltage Vad becomes stable after the time from time t8 to time t9, which is the time required for discharging the capacitor Ca and the capacitor Cb, has elapsed. In FIG. 9A, the door 19 is closed from time t7 to time t10.

However, the method of detecting the opening / closing of the door 19 having such a configuration has the following problems. When the output voltage Vcc of the low voltage power supply 110 drops from 24V to 12V after shifting from the normal mode to the power saving mode at time t8, the voltage Vad also drops from Vil2 to Vil1 as described in FIG. 9A. .. Here, FIG. 9B shows that the door 19 opens at a time shorter than the time from the time t8 to the time t9 until the voltage Vad stabilizes at Vil1 after the transition from the normal mode to the power saving mode at the time t8. It is a figure explaining the operation when it is opened and closed. The vertical axis, horizontal axis, and the like of FIG. 9B are the same as those of FIG. 9A, and redundant description will be omitted.

When the door 19 is opened and closed between the time t8 and the time t9 while the voltage Vad is decreasing from the Vil2 to the Vil1, for example, in a short time from the time ta to the time tb, the result is as follows. That is, when the door 19 is opened and closed in a short time from the time ta to the time tb, the voltage Vb of the other end Sd does not immediately become zero because the capacitor Cb is connected to the other end Sd of the switch 25. Therefore, the voltage Vad does not become equal to or less than the threshold voltage Vth1 in the power saving mode, in other words, the voltage Vad is larger than the threshold voltage Vth1, so that the CPU 100 has the door 19 opened between the time ta and the time tb. It cannot be judged that it has become.

On the other hand, when the door 19 is opened, the contact 15 and the contact arm 16 mechanically interlocked with the door 19 rotate, and the contact 15 is separated from the non-volatile memory 17. Therefore, the information output by the CPU 100 when trying to write to the non-volatile memory 17 between the time ta and the time tb may not be accurately written to the non-volatile memory 17. Further, since the CPU 100 cannot detect the open state of the door 19, there is a possibility that the recovery process of the information to be written to the non-volatile memory 17 between the time ta and the time tb cannot be performed.

1 and 2 are diagrams showing door open / close detection control in the open / close determination device of the first embodiment. The same configurations as those described with reference to FIGS. 7 to 8 (a) are designated by the same reference numerals, and the description thereof will be omitted. Here, the image forming apparatus is not limited to the configuration shown in FIG. 7 and the like, and if it has a configuration including a door 19 which is an opening / closing member and a switch 25 which is a switching means, another configuration such as a color image forming apparatus can be used. It may be an image forming apparatus of. Further, the description overlapping with the contents described in the graphs of FIGS. 8 (b) to 9 will be omitted. The feature of this embodiment is that the analog voltage Vad as a detection signal for determining the open / closed state of the door 19 is constantly monitored. Then, when the amount of change in the analog voltage Vad, specifically, the amount of decrease in the analog voltage Vad within a predetermined time becomes larger than the predetermined amount, it is determined that the door 19 is in the open state.

[Door open / close detection when shifting from normal mode to power saving mode]
FIG. 1 is a diagram showing door open / close detection control when the image forming apparatus shifts from the normal mode, which is the first mode, to the power saving mode, which is the second mode. During the period from time t7 to time t8, the image forming apparatus is operating in the normal mode, and the CPU 100, which is a determination means, compares the threshold voltage Vth2, which is the first threshold in the normal mode, with the voltage Vad. The open / closed state of the door 19 is determined. When the voltage Vad is larger than the threshold voltage Vth2 (Vth2 <Vad), the CPU 100 determines that the door 19 is in the closed state. On the other hand, when the voltage Vad is equal to or less than the threshold voltage Vth2 (Vad ≦ Vth2), the CPU 100 determines that the door 19 is in the open state.

As described above, the CPU 100 outputs the power saving signal to the low voltage power supply 110, for example, at time t8, the low voltage power supply 110 is switched from the normal mode to the power saving mode, and the threshold voltage is switched from Vth2 to Vth1.

During the period from time t8 to time t10, the image forming apparatus is operating in the power saving mode. The CPU 100 detects the open / closed state of the door 19 by comparing the threshold voltage Vth1 (<Vth2), which is the second threshold in the power saving mode lower than the threshold voltage Vth2, with the voltage Vad. When the voltage Vad is larger than the threshold voltage Vth1 (Vth1 <Vad), the CPU 100 determines that the door 19 is in the closed state. On the other hand, when the voltage Vad is equal to or less than the threshold voltage Vth1 (Vad ≦ Vth1), the CPU 100 determines that the door 19 is in the open state.

In this embodiment, the CPU 100 determines the open / closed state of the door 19 by comparing the threshold voltage Vth1 or the threshold voltage Vth2 with the voltage Vad, and makes the following determination. The CPU 100 sequentially monitors the voltage Vad, and sequentially determines whether or not the amount of decrease in the voltage Vad within the time Δt, which is a predetermined time, is larger than the preset predetermined amount ΔVth. Then, when the CPU 100 determines that the amount of decrease in the voltage Vad within the predetermined time Δt is larger than the predetermined amount ΔVth, the CPU 100 determines that the door 19 is in the open state.

As shown in FIG. 1, when the door 19 is opened at time ta after the transition from the normal mode to the power saving mode at time t8 and the door 19 is closed at time tb, the voltage Vad is the threshold voltage Vth1. It does not become the following. Therefore, the CPU 100 cannot detect that the door 19 is opened / closed in a short time from the time ta to the time tb by comparing the voltage Vad and the threshold voltage Vth1. However, in this embodiment, since it is sequentially determined whether or not the amount of change in the voltage Vad within the predetermined time Δt is larger than ΔVth, the CPU 100 opens and closes the door 19 even in the case shown in FIG. It can detect that there was an operation. Here, the time from time ta to time tb is the shortest time in the opening and closing operation of the door 19, and the predetermined time Δt is shorter than the time from time ta to time tb.

Specifically, it is assumed that the CPU 100 has a timer (not shown), and the timer (not shown) manages the measurement of the predetermined time Δt. Further, the value of the voltage Vad at each time is temporarily stored in a memory (not shown). The CPU 100 determines that the door 19 is in the open state when the voltage Vad at the current time is smaller than the voltage Vad before the predetermined time Δt from ΔVth.

[Door open / close detection when shifting from power saving mode to normal mode]
FIG. 2 shows a method of detecting the opening / closing of the door 19 when switching from the power saving mode to the normal mode. The CPU 100 stops the power saving signal LMV output to the low voltage power supply 110. At time t12, the CPU 100 changes the low voltage power supply 110 from the output voltage Vcc (for example, 12V) which is the second DC voltage in the power saving mode to the output voltage Vcc (for example, 24V) which is the first DC voltage in the normal mode. Switch. Therefore, the image forming apparatus operates in the normal mode from the time t12 to the time t14. However, the output voltage Vcc of the low voltage power supply 110 does not switch immediately, and is determined after the time required for charging the capacitors Ca and Cb and the time required for the output voltage Vcc of the low voltage power supply 110 to stabilize have elapsed. It stabilizes at the voltage of (for example, 24V). Therefore, the CPU 100 switches the threshold voltage from Vth1 to Vth2 from the time t12 when the power saving signal LVM is stopped to the time t13 when the time Twait, which is the second time, has elapsed. Here, the time Twait is a longer time than the time Tup (Tup <Twait).

After the time t13, the CPU 100 compares the threshold voltage Vth2 with the voltage Vad and detects the open / closed state of the door 19. When the CPU 100 determines that the voltage Vad is larger than the threshold voltage Vth2 (Vth2 <Vad), the CPU 100 determines that the door 19 is in the closed state. On the other hand, when the CPU 100 determines that the voltage Vad is equal to or less than the threshold voltage Vth2 (Vad ≦ Vth2), the CPU 100 determines that the door 19 is in the open state.

As shown in FIG. 2, when the door 19 is opened at time tc and the door 19 is closed at time td after the transition from the power saving mode to the normal mode at time t12, the threshold voltage is changed from Vth1 to Vth2. Since it has not been switched to, Vth1 is used as the threshold voltage. Therefore, the voltage Vad does not become equal to or less than the threshold voltage Vth1, and the CPU 100 cannot detect that the door 19 is in the open state by comparing the voltage Vad with the threshold voltage Vth1. However, in this embodiment, since it is sequentially determined whether or not the amount of change in the voltage Vad within the predetermined time Δt is larger than ΔVth, the CPU 100 opens and closes the door 19 even in the case shown in FIG. It can detect that there was an operation. Here, the predetermined time Δt is set to be shorter than the time from the time tc to the time td.

In this embodiment, the CPU 100 sequentially performs the following determination together with the process of determining the open / closed state of the door 19 by comparing the threshold voltage Vth1 or the threshold voltage Vth2 with the voltage Vad. The CPU 100 sequentially monitors the voltage Vad and determines whether or not the amount of decrease in the voltage Vad within the predetermined time Δt is larger than the predetermined predetermined amount ΔVth. When the CPU 100 determines that the amount of decrease in the voltage Vad within the predetermined time Δt is larger than the predetermined amount ΔVth, the CPU 100 determines that the door 19 is in the open state.

As described above, in this embodiment, the CPU 100 constantly monitors the analog voltage Vad of the detection signal. When the CPU 100 determines that the amount of decrease in the analog voltage Vad within the predetermined time Δt is larger than the predetermined amount ΔVth, the CPU 100 determines that the door 19 is in the open state. Thereby, in this embodiment, even when the output voltage Vcc of the low voltage power supply 110 changes, the open / closed state of the door 19 can be accurately detected.

[When the opening / closing judgment of this embodiment is applied to the image forming apparatus]
(Recovery operation)
The effect of applying the door open / close detection control described in this embodiment to the image forming apparatus will be described below. When the image forming apparatus shifts from the normal mode to the power saving mode, the output voltage Vcc of the low voltage power supply 110 drops from, for example, 24V to 12V. As shown in FIG. 1, the voltage Vad also drops from Vil2 to Vil1 from time t8 to time t9 while the output voltage Vcc of the low voltage power supply 110 is dropping. When the door 19 is opened and closed in a short time from time ta to time tb between time t8 and time t9, the capacitor Cb is connected to the other end Sd of the switch 25, so that the voltage Vb on the other end Sd side is connected. Does not instantly become zero. Therefore, as described with reference to FIG. 9B, the conventional door open / close detection cannot detect the open / closed state of the door 19 for a short time from the time ta to the time tb. When the door 19 is opened, the contact 15 and the contact arm 16 which are the connection portions mechanically interlocked with the door 19 rotate and are separated from the non-volatile memory 17 which is the first storage means. Therefore, the information written in the non-volatile memory 17 between the time ta and the time tb may not be accurately written in the non-volatile memory 17. Further, since the CPU 100 cannot detect that the door 19 has been opened, the CPU 100 cannot perform the recovery process of the stored information of the non-volatile memory 17.

On the other hand, by adopting the door open / close detection control described in this embodiment, the CPU 100 can detect the open / closed state of the door 19 for a short time from the time ta to the time tb. When the door 19 is opened, the contact 15 and the contact arm 16 that are mechanically interlocked with the door 19 rotate, and the contact 15 is separated from the non-volatile memory 17. Therefore, the information written in the non-volatile memory 17 between the time ta and the time tb may not be accurately written in the non-volatile memory 17. In the present embodiment, when the CPU 100 detects that the door 19 is in the open state, the information that needs to be written to the non-volatile memory 17 from the time ta to the time tb is temporarily stored as the second storage means. It is stored in RAM100b or the like. For example, the CPU 100 stores the latest information of Δt (predetermined time) among the information written in the non-volatile memory 17 in the RAM 100b or the like. After detecting that the door 19 has changed from the open state to the closed state, the CPU 100 can perform a recovery operation by reading the information for Δt stored in the RAM 100b or the like and writing it in the non-volatile memory 17. it can.

(Initialization operation)
Further, another effect when the door open / close detection control described in this embodiment is applied to the image forming apparatus will be described below. FIG. 3A is a diagram showing an image forming apparatus with the door 19 closed. The difference from FIG. 7 is that the removable cartridge 9 contains the first region 9a, which is the first image forming portion containing the photosensitive drum 5 and the charging roller 6, and the developing sleeve 7 and the toner 8. The structure is divided into a second region 9b, which is an image forming portion of the above. In the image forming apparatus shown in FIG. 3A, the second region 9b of the cartridge 9 can rotate about the shaft 20 and is separated from the first region 9a as shown in FIG. 3B. If the photosensitive drum 5 and the developing sleeve 7 are in constant contact with each other when the image forming apparatus is in the standby state, the developing sleeve 7 may be deformed. In order to prevent deformation of the developing sleeve 7, the first region 9a and the second region 9b of the cartridge 9 are configured so as to be in contact with each other and separated from each other. The separation operation and the contact operation between the first region 9a and the second region 9b of the cartridge 9 are performed by the driving force of the motor 21 which is the driving means.

The electric power to the motor 21 for performing the contact operation and the separation operation between the first region 9a and the second region 9b of the cartridge 9 is on the downstream side of the switch 25 (the other end Sd side (see FIG. 8A)). Supplied from. Therefore, when the door 19 is open and the switch 25 is off, power is not supplied to the motor and the separation operation cannot be performed. Therefore, when the door 19 is opened by mechanically interlocking with the opening / closing operation of the door 19, the first region 9a and the second region 9b of the cartridge 9 do not use the driving force of the motor 21. A structure that separates them is adopted. When the door 19 is in the closed state, the contact and separation operations of the first region 9a and the second region 9b of the cartridge 9 are performed by the driving force of the motor 21. FIG. 3B shows the configuration of the image forming apparatus when the door 19 is opened. On the other hand, when the door 19 is changed from the open state to the closed state, the motor 21 is driven to bring the first region 9a and the second region 9b of the cartridge 9 into contact with each other (referred to as an initialization operation).

When the image forming apparatus having the configuration of FIG. 3 shifts from the normal mode to the power saving mode, the voltage Vad also changes from Vil2 to Vil1 during the period from time t8 to time t9 while the output voltage Vcc of the low voltage power supply 110 is decreasing. descend. When the door 19 is opened and closed in a short time from time ta to time tb between time t8 and time t9, the voltage Vb of the other end Sd is changed because the capacitor Cb is connected to the other end Sd of the switch 25. It does not become zero instantly. Therefore, the conventional door opening / closing detection control shown in FIG. 9B cannot detect the opening / closing of the door 19 for such a short time. When the door 19 is opened at time ta, the first region 9a and the second region 9b of the cartridge 9 are separated from each other by mechanically interlocking with the state of the door 19. However, even if the door 19 is closed at time tb, the CPU 100 cannot detect the opening / closing of the door 19 by the conventional door opening / closing detection. Therefore, there is a problem that the initialization operation of bringing the first region 9a and the second region 9b of the separated cartridges 9 into contact with each other cannot be performed, which causes a malfunction of the image forming apparatus.

On the other hand, when the door opening / closing detection control described in this embodiment is applied, the opening / closing of the door 19 for a short time as described above can be detected. Therefore, the motor 21 can be driven when the door 19 is changed from the open state to the closed state at time tb, and the initialization operation of bringing the first region 9a and the second region 9b of the cartridge 9 into contact with each other can be performed. it can.

As described above, according to this embodiment, it is possible to more accurately detect the opening and closing of the door even when the output voltage of the power supply changes.

In the first embodiment, the CPU 100 constantly monitors the analog voltage Vad of the detection signal corresponding to the opening and closing of the door 19, and when the decrease amount of the analog voltage Vad within the predetermined time Δt becomes larger than the predetermined amount ΔVth, the door It is determined that 19 is in the open state. In the first embodiment, the predetermined amount ΔVth for comparing the decrease amount of the analog voltage Vac within the predetermined time Δt is configured as follows. That is, in the first embodiment, the predetermined amount ΔVth of the analog voltage when switching from the normal mode to the power saving mode and the predetermined amount ΔVth of the analog voltage when switching from the power saving mode to the normal mode are the same. In this way, by making the predetermined amount ΔVth the same when switching from the normal mode to the power saving mode and when switching from the power saving mode to the normal mode, the door open / close detection control by the CPU 100 becomes simple. There is an advantage.

On the other hand, the analog voltage value that decreases during a predetermined time Δt differs depending on the change in the output voltage Vcc of the low voltage power supply 110. Therefore, in the second embodiment, in order to detect the opening / closing of the door 19 more accurately, the door opening / closing detection control for setting a predetermined amount ΔVth according to the voltage change of the output voltage Vcc will be described. The same components as those already described are designated by the same reference numerals, and the description thereof will be omitted.

[Door open / close detection control when shifting from normal mode to power saving mode]
After shifting from the normal mode to the power saving mode at time t8 shown in FIG. 4A, the predetermined amount ΔVtha used for detecting the opening / closing of the door 19 is obtained as follows. That is, the voltage value Vad (t = t1-Δt) of the voltage Vad at a predetermined time (t1-Δt) before the predetermined time Δt from the time t1 is used to obtain the following equation (1).
ΔVtha = α × Vad (t = t1-Δt) ... Equation (1)
In the formula (1), α is a predetermined constant experimentally determined from the relationship between the output voltage Vcc and the voltage Vad after Δt after the switch 25 is opened. In this embodiment, the CPU 100 determines that the door 19 is in the open state when the amount of decrease in the voltage Vad within the predetermined time Δt is larger than the voltage ΔVtha calculated by the equation (1).

[Door open / close detection control when shifting from power saving mode to normal mode]
After shifting from the power saving mode to the normal mode at the time t12 shown in FIG. 4B, the predetermined amount ΔVthc used for detecting the opening / closing of the door 19 is obtained as follows. That is, the voltage value Vad (t = t2-Δt) of the voltage Vad at a predetermined time (t2-Δt) before the predetermined time Δt from the time t2 is used to obtain the following equation (2).
ΔVthc = α × Vad (t = t2-Δt) ... Equation (2)
In equation (2), α has the same value as α used in equation (1).

In this embodiment, the CPU 100 determines that the door 19 is in the open state when the amount of decrease in the voltage Vad within the predetermined time Δt is larger than the voltage ΔVthc calculated by the equation (2). As described above, in the present embodiment, a predetermined amount ΔVth (ΔVtha, ΔVthc) for comparison with the decrease amount of the voltage Vad according to the voltage change of the output voltage Vcc of the low voltage power supply 110, that is, the voltage change of the voltage Vad. To set. As a result, the opening and closing of the door 19 can be detected more accurately.

As described above, according to this embodiment, it is possible to more accurately detect the opening and closing of the door even when the output voltage of the power supply changes.

In the first and second embodiments, the threshold voltages Vth1 and Vth2 are compared with the voltage Vad to detect the opening / closing of the door 19, and the decrease amount of the voltage Vad within the predetermined time Δt is compared with the predetermined amount ΔVth. It also detects the opening and closing of the door 19. The CPU 100 determines that the door 19 is in the open state when the amount of decrease in the voltage Vad within the predetermined time Δt becomes larger than the predetermined amount ΔVth. In the third embodiment, in order to detect the opening / closing of the door more easily, the voltage Vad is monitored, and when the decrease amount of the voltage Vad within the predetermined time Δt becomes larger than the predetermined amount ΔVth, the door 19 is opened. Door open / close detection is performed according to the configuration that determines that the door has been opened or closed. The same components as those described above are designated by the same reference numerals, and the description thereof will be omitted.

[Door open / close detection in normal mode]
FIG. 5 is a diagram illustrating door open / close detection in this embodiment. In FIG. 5, a method of detecting the open / closed state of the door 19 in the normal mode from the time t20 to the time t21 will be described. Here, the door 19 is opened at time te and closed at time tf. Using the voltage value Vad (t = t3-Δt) of the voltage Vad at the predetermined time (t3-Δt) before the predetermined time Δt from the time t3, the predetermined amount ΔVthe used for detecting the opening / closing of the door 19 is as follows. It is calculated as in equation (3).
ΔVthe = α × Vad (t = t3-Δt) ・ ・ ・ Equation (3)
In the formula (3), α is a predetermined constant determined in the same manner as α in the formulas (1) and (2). When the CPU 100 determines that the amount of decrease in the voltage Vad within the predetermined time Δt is larger than the predetermined amount ΔVthe calculated by the equation (3), the CPU 100 determines that the door 19 is in the open state.

[Door open / close detection in power saving mode]
In FIG. 5, a method of detecting the open / closed state of the door 19 in the power saving mode from the time t22 to the time t23 will be described. Here, the door 19 is opened at time tg and closed at time th. Using the voltage value Vad (t = t4-Δt) of the voltage Vad at the predetermined time (t4-Δt) before the predetermined time Δt from the time t4, the predetermined amount ΔVthg used for detecting the opening / closing of the door 19 is as follows. It is calculated as in equation (4).
ΔVthg = α × Vad (t = t4-Δt) ... Equation (4)
In equation (4), α has the same value as α used in equation (3). When the CPU 100 determines that the amount of decrease in the voltage Vad within the predetermined time Δt is larger than the predetermined amount ΔVthg calculated by the equation (4), the CPU 100 determines that the door 19 is in the open state.

[Door open / close detection when shifting from normal mode to power saving mode]
A method of detecting the open / closed state of the door 19 after shifting from the normal mode to the power saving mode at the time t8 shown in FIG. 6A will be described. Here, the door 19 is opened at time tp and closed at time tq. Using the voltage value Vad (t = t5-Δtp) of the voltage Vad at a predetermined time (t5-Δt) before the predetermined time Δt from the time t5, the predetermined amount ΔVthp used for detecting the opening / closing of the door 19 is as follows. It is calculated as in equation (5).
ΔVthp = α × Vad (t = t5-Δt) ... Equation (5)
In equation (5), α has the same value as α used in equation (3). When the CPU 100 determines that the amount of decrease in the voltage Vad within the predetermined time Δt is larger than the predetermined amount ΔVthp calculated by the equation (5), the CPU 100 determines that the door 19 is in the open state.

[Door open / close detection when shifting from power saving mode to normal mode]
A method of detecting the open / closed state of the door 19 after shifting from the power saving mode to the normal mode at the time t12 shown in FIG. 6B will be described. Here, the door 19 is opened at time tr and closed at time ts. The predetermined amount ΔVthq used for detecting the opening / closing of the door 19 is subjected to the following by using the voltage value Vad (t = t6-Δt) of the voltage Vad at a predetermined time (t6-Δt) before the predetermined time Δt from the time t6. It is calculated as in equation (6).
ΔVthq = α × Vad (t = t6-Δt) ・ ・ ・ Equation (6)
In equation (6), α has the same value as α used in equation (3). When the CPU 100 determines that the amount of decrease in the voltage Vad within the predetermined time Δt is larger than the predetermined amount ΔVthq calculated by the equation (6), the CPU 100 determines that the door 19 is in the open state.

As described above, in this embodiment, the analog voltage Vad of the detection signal is constantly monitored. Then, the CPU 100 determines that the door 19 is in the open state when the amount of decrease in the voltage Vad within the predetermined time Δt becomes larger than the predetermined amount (ΔVthe, ΔVthg, ΔVthp, ΔVthq). In this embodiment, door open / close detection can be performed more easily by performing only door open / close detection control based on the amount of decrease in voltage Vad.

As described above, according to this embodiment, it is possible to more accurately detect the opening and closing of the door even when the output voltage of the power supply changes.

In the first to third embodiments, a configuration for accurately detecting the opening and closing of the door even if the output voltage of the power supply changes has been described. In this embodiment, an example of a configuration for detecting the opening / closing of a door while reducing power consumption will be described below.

FIG. 10 shows the configuration of the electric circuit in this embodiment, and FIG. 11 shows a method (timing chart) for detecting door opening / closing in this embodiment. Further, the configuration of the image forming apparatus in this embodiment is the same as that in FIG. In this embodiment, the voltage Vad is detected by switching to the general-purpose input circuit 120 in the power saving mode in which high responsiveness is not required when detecting the opening / closing of the door. At this time, by stopping the operation of the A / D input conversion module 121, the power consumption of the CPU 100 during power saving is reduced. The description of the electrical connection common to FIG. 8 will be omitted.

In FIG. 10, an A / D input conversion module 121 capable of switching between start and stop is provided inside the CPU 100. Further, the CPU 100 that detects the voltage Vad is provided with an input terminal that serves as both an A / D input conversion port and a general-purpose input port. The general-purpose input circuit 120 is a circuit that detects the input analog voltage value as it is. Power consumption is small because the A / D input conversion module 121 is not used.

A door open detection method will be described with reference to FIG. FIG. 11A shows a change in the voltage Vad when the door is opened / closed (closed → opened). Further, FIG. 11B shows the opened / closed state of the door. FIG. 11C shows the opening / closing detection of the door 19 in the normal mode. FIG. 11D shows the opening / closing detection of the door 19 in the power saving mode. Note that Vth2 is a threshold value for determining the door open in the normal mode, and Vth1 is a threshold value for determining the door open in the power saving mode. In the normal mode, the CPU 100 detects the voltage Vad with the A / D input conversion module 121. The CPU 100 compares the threshold voltage Vth2 with the voltage Vad and detects the open / closed state of the door 19. When the voltage Vad is larger than the threshold voltage Vth2 (Vth2 <Vad), the CPU 100 determines that the door is closed. The CPU 100 determines that the door is open when the voltage Vad is the threshold voltage Vth2 or less (Vad ≦ Vth2). Therefore, as shown in FIG. 11 (c), when the door 19 is opened at the time t2, the CPU 100 determines that the door is closed between the time t1 and the time t3, and determines that the door is open after the time t3.

The CPU 100 detects the voltage Vad by switching the connection with the input terminal from the A / D input conversion module 121 to the general-purpose input circuit 120 by the switch 122. The CPU 100 stops the operation of the A / D input conversion module 121 in the power saving mode. The CPU 100 compares the threshold voltage Vth2 (Vth2 <Vth1) with the voltage Vad, and detects the open / closed state of the door 19. The CPU 100 determines that the door is closed when Vth2 <Vad, and determines that the door is open when Vad ≦ Vth2. Therefore, as shown in FIG. 11D, when the door is opened at time t2, the CPU 100 determines that the door is closed between time t1 and time t6, and determines that the door is open after time t6. Since the A / D input conversion module 121 is in the stopped state, it is possible to reduce the power consumption by that amount.

As described above, the CPU 100 is a switching unit that switches the function between the normal mode and the power saving mode. Specifically, in the normal mode, the A / D input conversion module 121 detects the opening / closing of the door 19, and in the output saving mode, the A / D input conversion module 121 switches to the general-purpose input circuit 120 to detect the opening / closing of the door 19. When switching to the general-purpose input circuit 120, the power consumption of the CPU 100 can be reduced by stopping the A / D input conversion module 121.

The operation when the method of detecting the opening / closing of the door 19 described in this embodiment is applied to the image forming apparatus will be described. As shown in FIG. 11, when the door 19 is opened, the voltage of the capacitor Cb does not instantly become zero due to the influence of the counter electromotive force of the motor M when the motor M is operating, and the voltage of the voltage Vad does not become zero instantly, but slowly. And descend. In the normal mode, the A / D input conversion module 121 detects the voltage Vad to detect the opening / closing of the door 19, so that the opening / closing of the door 19 can be detected at an early stage in a short time. At this time, the contact arm 16 mechanically linked (not shown) to the door 19 rotates, and the contact 15 is separated from the non-volatile memory 17 so that data cannot be written. However, since the timing of detecting the opening / closing of the door 19 is early, the CPU 100 can detect that the door 19 has opened and secure the time required for writing to the non-volatile memory 17.

On the other hand, in the state of transition from the normal mode to the power saving mode, first, the CPU 100 prohibits communication with the non-volatile memory 17. Next, the input terminal of the CPU 100 that detects the voltage Vad is switched from the A / D input conversion module 121 to the general-purpose input circuit 120 by the switch 122. Then, the power supply of the A / D input conversion module 121 in the CPU 100 is turned off. In this state, when it becomes necessary to communicate with the non-volatile memory 17, the communication with the non-volatile memory 17 is performed after the transition from the power saving mode to the normal mode.

A method of detecting door opening / closing in the power saving mode will be described with reference to FIG. (A) to (c) of FIG. 12 are the same graphs as (a) to (c) of FIG. 11, and the description overlapping with the description of FIG. 11 is omitted. FIG. 12D shows communication settings (permission, prohibition) with the non-volatile memory 17. In the power saving mode, the CPU 100 detects the voltage Vad by the general-purpose input circuit 120 and detects the opening / closing of the door 19. At this time, in order for the CPU 100 to detect the opening of the door, a time (t6-t2) longer than the detection time (t3-t2) in the normal mode is required. Therefore, when the door 19 is opened and closed in a short time of about several hundred milliseconds between the time t2 and the time t6, the opening and closing of the door 19 cannot be detected (t5-t2). However, since communication with the non-volatile memory 17 is prohibited in the power saving mode, no abnormality occurs, so that it is not necessary to detect it. On the other hand, regarding the power consumption, since the operation of the A / D input conversion module 121 inside the CPU 100 is stopped, it is possible to reduce the power consumption by this amount. Specifically, in this embodiment, the reduction is about 20 mW.

In this embodiment, when a plurality of motors having different specifications are used, the CPU 100 detects the voltage value of the voltage Vad when the door is closed by the A / D input conversion module 121, and controls the motors according to the detected values. Is assumed to be switched. As described above, the method of suppressing the power in the power saving mode state in the image forming apparatus that performs the optimum control according to the type of the motor is characteristic.

As the image forming apparatus, for example, motors having different specifications may be purchased from a plurality of manufacturers (multiple vendors) and used. By individually optimizing the rotation control gain for the motors of each vendor with different specifications in this way, the motor of the drive unit for transporting the seat can reduce the rotation variation and obtain a good image. Obtainable.

FIG. 13 shows the electrical connection of this embodiment. The CPU 100 outputs a motor control signal to the motor unit to control the motor M. The same reference numerals are used for the parts common to FIG. 10 described above, and the differences will be described below by omitting the description. As the motor M shown in FIG. 13 (a), it is assumed that the motor M1 (FIG. 13 (b)) and the motor M2 (FIG. 13 (c)) having different specifications are selected and used. A non-volatile memory 17 is provided inside the CPU 100, and a gain value of rotation control optimized for each motor is recorded in each storage unit in the non-volatile memory 17. As shown in FIGS. 13B and 13C, the motor M1 is configured with the motor unit 1, and the motor M2 is configured with the motor unit 2.

The CPU 100 and the low voltage power supply 110 are units common to the motor M1 and the motor M2. The voltage dividing resistors Ra and Rb that generate the voltage Vad are mounted on the motor unit, respectively. The voltage dividing resistors Ra1 and Rb1 are mounted on the motor unit 1. The voltage dividing resistors Ra2 and Rb2 are mounted on the motor unit 2. The resistance value of each resistor has the relationship of the following equation (7).
Rb1 / (Ra1 + Rb1) ≠ Rb2 / (Ra2 + Rb2) ... Equation (7)
Further, the voltage value of each voltage Vad when the door is closed is as shown in the following equations (8) and (9).
Voltage when the door is closed when the motor unit is 1 Vad (Vil1)
Vil1 = Rb1 / (Ra1 + Rb1) x Vb ... Equation (8)
Voltage when the door is closed when the motor unit 2 is closed Vad (Vil2)
Vil2 = Rb2 / (Ra2 + Rb2) × Vb ... Equation (9)
Further, the relationship between the threshold voltage Vth3 used for discriminating the Vil1 and Vil2 and the motor is as shown in the following equation (10).
Vil1>Vth3> Vil2 ... Equation (10)
FIG. 14 is a flowchart showing a method of determining the control constant of the motor M at the time of transition to the normal mode, and the determination method will be described below. In the transition to the normal mode, in step 02 (hereinafter referred to as S) 02, the CPU 100 detects the voltage value of the voltage Vad by the A / D input conversion module 121, and detects the opening / closing of the door 19. The CPU 100 determines whether or not the voltage Vad is larger than the threshold voltage Vth1. If the CPU 100 determines in S02 that Vad ≦ Vth1, the process proceeds to S03. In S03, the CPU 100 determines that the door is open, returns the process to S02, and repeats the detection of the voltage Vad until the door is closed. If the CPU 100 determines in S02 that Vad> Vth1, the process proceeds to S04. In S04, the CPU determines that the door is closed.

In S05, the CPU 100 determines whether or not the voltage Va is larger than the threshold voltage Vth3. If the CPU 100 determines in S05 that Vad> Vth3, the process proceeds to S06. In S06, the CPU 100 determines that the motor M1 is connected, and sets the rotation control constant of the motor M to a constant optimized for the motor M1. The CPU 100 is set to perform drive control of the motor M with a constant set for the motor M1, and is in a standby state. If the CPU 100 determines in S05 that Vad ≦ Vth3, the process proceeds to S07. In S07, the CPU 100 determines that the motor M2 is connected, and sets the rotation control constant of the motor M to a constant optimized for the motor M2. The CPU 100 is set to perform drive control of the motor M with a constant set for the motor M2, and is in a standby state. In this way, when it is determined that the door 19 is in the closed state in the normal mode, the voltage Vad value is detected by the A / D input conversion module 121 to perform the rotation control optimized for each motor having different specifications. It becomes possible.

On the other hand, in the power saving mode, the voltage Vad is detected by the general-purpose input circuit 120 to detect the opening and closing of the door 19. Therefore, since the voltage value when the door is closed cannot be read, the motor M cannot be identified. However, in the power saving mode, the image forming apparatus does not form an image, so that it is not necessary to drive the motor M. Therefore, it is not necessary to distinguish whether the motor M is the motor M1 or the motor M2. Therefore, the detection of the general-purpose input circuit 120 may be sufficient. On the other hand, regarding the power consumption, since the operation of the A / D input conversion module 121 inside the CPU 100 is stopped, it is possible to suppress the power consumption by this amount.

With this configuration, when a plurality of motors with different specifications are used for the motor M, the CPU 100 detects the voltage value of the voltage Vad when the door is closed by the A / D input conversion module 121, and the detection result is obtained. The control of the motor M is switched according to the above. This makes it possible to suppress the power in the power saving mode state while performing optimum control for the motors of each vendor.

25 switch 100 CPU
110 Low voltage power supply Cb capacitor

Claims (20)

An output means that converts AC voltage and outputs DC voltage,
A switch means in which the output means is connected to one end, and the DC voltage output by the output means is supplied to the load in the closed state and cut off from the load in the open state.
A capacitor connected to the other end of the switch means
In the period when the DC voltage output from the output means is changing, when the amount of decrease in the voltage at the other end of the switch means within a predetermined time becomes larger than the predetermined amount , the switch means is opened. Judgment means to judge that it became
An opening / closing judgment device characterized by being provided with. The opening / closing determination device according to claim 1, wherein the reduction amount is determined according to the DC voltage output from the output means. The opening / closing determination device according to claim 2 , wherein the reduction amount is determined based on the voltage at the other end of the switch means at a predetermined time and a predetermined constant. The determination means includes a first mode in which a first DC voltage is output from the output means, and a second mode in which a second DC voltage lower than the first DC voltage is output from the output means. It is possible to switch between
The determination means is switched between the first mode and the second mode, and while the DC voltage is a voltage between the first DC voltage and the second DC voltage . Claim 1 to claim 1 , wherein it is determined that the switch means is in the open state when the decrease amount of the voltage at the other end of the switch means within a predetermined time becomes larger than the predetermined amount. The open / close determination device according to any one of 3. In the first mode, it is determined whether the switch means is in the open state or the closed state by comparing the voltage at the other end of the switch means with the first threshold value.
In the second mode, it is determined whether the switch means is in the open state or the closed state by comparing the voltage at the other end of the switch means with the second threshold value lower than the first threshold value. The open / close determination device according to claim 4. When the determination means shifts from the first mode to the second mode, the determination means switches from the first threshold value to the second threshold value, and shifts from the second mode to the first mode. The opening / closing determination device according to claim 5 , wherein the second threshold value is switched to the first threshold value after the second time has elapsed. An output means that converts AC voltage and outputs DC voltage,
A switch means in which the output means is connected to one end, and the DC voltage output by the output means is supplied to the load in the closed state and cut off from the load in the open state.
A capacitor connected to the other end of the switch means
An opening / closing member for accessing the inside of the image forming apparatus, wherein the switch means is also in the open state when the image forming device is in the open state, and the switch means is also in the closed state when the image forming device is in the closed state.
In the period when the DC voltage output from the output means is changing, when the amount of decrease in the voltage at the other end of the switch means within a predetermined time becomes larger than a predetermined amount , the opening / closing member is opened. Judgment means to judge that it became
An image forming apparatus comprising. An image forming unit having a first storage means and for forming a toner image on a recording material,
A connection unit for recording information about the image forming unit in the first storage means. When the opening / closing member is in the closed state, the opening / closing member is in contact with the first storage means, and the opening / closing member is in the open state. At the time of, the connection part which becomes non-contact with the first storage means,
With
The image forming apparatus according to claim 7 , wherein the determination means performs a recovery operation of the first storage means when it is determined that the opening / closing member is in the open state. A second storage means for storing the latest information for the predetermined time among the information written in the first storage means is provided.
The recovery operation is an operation of writing the information for the predetermined time written in the second storage means to the first storage means after the opening / closing member is closed. The image forming apparatus according to claim 8. The first image forming part for forming a toner image on the recording material,
An image forming portion for forming a toner image on a recording material, and the first image is linked to the opening / closing member being opened in contact with or separated from the first image forming portion. A second image forming part separated from the forming part,
With
The image forming apparatus according to claim 7 , wherein the determining means performs an initialization operation of the second image forming unit when it is determined that the opening / closing member has changed from the open state to the closed state. A driving means for driving the second image forming unit is provided.
The initialization operation is an operation in which the second image forming portion is brought into contact with the first image forming portion by the driving means after the opening / closing member is closed. 10. The image forming apparatus according to 10. The image forming apparatus according to any one of claims 7 to 11 , wherein the amount of reduction is determined according to the DC voltage output from the output means. The image forming apparatus according to claim 7 , wherein the amount of reduction is determined based on the voltage at the other end of the switch means at a predetermined time and a predetermined constant. The determination means includes a first mode in which a first DC voltage is output from the output means, and a second mode in which a second DC voltage lower than the first DC voltage is output from the output means. It is possible to switch between
The determination means is switched between the first mode and the second mode, and while the DC voltage is a voltage between the first DC voltage and the second DC voltage . According to claim 7, it is determined that the switch means is in the open state when the amount of decrease in the voltage at the other end of the switch means within a predetermined time becomes larger than the predetermined amount. Item 3. The image forming apparatus according to any one of Items 13. In the first mode, it is determined whether the switch means is in the open state or the closed state by comparing the voltage at the other end of the switch means with the first threshold value.
In the second mode, it is determined whether the switch means is in the open state or the closed state by comparing the voltage at the other end of the switch means with the second threshold value lower than the first threshold value. The image forming apparatus according to claim 14. When the determination means shifts from the first mode to the second mode, the determination means switches from the first threshold value to the second threshold value, and shifts from the second mode to the first mode. The image forming apparatus according to claim 15 , further comprising switching from the second threshold value to the first threshold value after the second time has elapsed. An output means that converts AC voltage and outputs DC voltage,
A switch means in which the output means is connected to one end, and the DC voltage output by the output means is supplied to the load in the closed state and cut off from the load in the open state.
A capacitor connected to the other end of the switch means
The first detecting means for detecting the voltage at the other end of the switch means and
A second detecting means for detecting the voltage at the other end of the switch means,
Switching between switching between detecting the voltage at the other end with the first detecting means and detecting the voltage at the other end with the second detecting means according to the DC voltage output from the output means. Means and
A determination means for determining whether the opening / closing member is in the open state or the closed state based on the result detected by the first detection means or the second detection means.
An open / close judgment device characterized by being provided. When the DC voltage is the first voltage, the switching means switches so that the first detecting means detects the voltage at the other end, and the DC voltage is lower than the first voltage. The open / close determination device according to claim 17 , wherein in the case of a voltage, the second detecting means switches to detect the voltage at the other end. The first detection means is an A / D input conversion module, the second detection means is a general-purpose input circuit, and when the second detection means detects the voltage at the other end, the A The opening / closing determination device according to claim 17 or 18 , wherein the operation of the / D input conversion module is stopped. An output means that converts AC voltage and outputs DC voltage,
A switch means in which the output means is connected to one end, and the DC voltage output by the output means is supplied to the load in the closed state and cut off from the load in the open state.
A capacitor connected to the other end of the switch means
An opening / closing member for accessing the inside of the image forming apparatus, wherein the switch means is also in the open state when the image forming device is in the open state, and the switch means is also in the closed state when the image forming device is in the closed state.
The first detecting means for detecting the voltage at the other end of the switch means and
A second detecting means for detecting the voltage at the other end of the switch means,
Switching between switching between detecting the voltage at the other end with the first detecting means and detecting the voltage at the other end with the second detecting means according to the DC voltage output from the output means. Means and
A determining means for determining whether the opening / closing member is in the open state or the closed state based on the result detected by the first detecting means or the second detecting means.
An image forming apparatus comprising.

Images