JPH09197879A - Image recording device - Google Patents

Abstract

(57) An object of the present invention is to provide an image forming apparatus capable of reliably preventing erroneous connection of a heater. SOLUTION: A halogen heater 1 is attached to a connector 14f.
Connect only the common terminal of 4c and the halogen heater 14e,
Only the non-common terminals of the halogen heater 14c and the halogen heater 14e are connected to the connector 14g.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus provided with a heat fixing device for fixing a developer transferred onto a recording material by applying heat and pressure with a heat roller using a plurality of heaters having different light distributions.

[0002]

2. Description of the Related Art Conventionally, an image recording apparatus such as a printer or a copying machine is provided with a heat fixing device using a heat roller. This heat roller is, for example, a metal roller having an elastic layer on its surface. In general, a halogen heater is arranged inside.

A pressure roller is arranged in pressure contact with the heat roller, and a recording material carrying an unfixed toner image is nipped and conveyed at the pressure contact portion,
Heat is applied to the recording material and the unfixed toner image through a heat roller and the pressure is applied by both rollers to fix the toner.

However, the size of the recording material used in the image recording apparatus is large and small, and if a single halogen heater is used to heat the entire area of the roller pressing portion in the longitudinal direction in accordance with the largest recording material, When a recording material having a small width is used, heat is not absorbed by the recording material in a region of the roller pressing portion where the recording material does not pass, so that the temperature may rise to a very high temperature.

Therefore, conventionally, a plurality of halogen heaters having different light distributions are used in the longitudinal direction of the roller pressing portion, for example, a first halogen heater having a peak in a passage area of a recording material having a small width and a non-passage. A second halogen heater having a peak in a region, and when fixing a recording material having a small width, the first halogen heater emits light, and when fixing a recording material having a large width, both halogen heaters emit light. The abnormal temperature rise in the non-passage area was prevented during fixing of the recording material with a small width.

[0006]

However, in the image recording apparatus having the thermal fixing device using the heaters having different light distributions as in the above-mentioned conventional example, if the heaters are incorrectly connected, the halogen heater Since the light emission is not performed, the fixing may not be normally performed, and the paper may be discharged without being fixed.

Therefore, an object of the present invention is to provide an image recording apparatus capable of preventing erroneous connection of heaters.

[0008]

SUMMARY OF THE INVENTION According to the present invention, the above object is to provide a fixing device for fixing a developer image transferred on a recording material by applying heat and pressure using a plurality of heaters having different light distributions. In the image recording apparatus having the above, it has a plurality of connectors for connecting the heater and the power source, and separates a common terminal connected to the power line of the heater and a non-common terminal connected to the control line into separate connectors. It is achieved by connecting with.

That is, in the present invention, a plurality of connectors are used to divide into a connector to which a common terminal connected to the power supply line of the heater is connected and a connector to which a non-common terminal connected to the control line is connected. This prevents erroneous connection between the common terminal and the non-common terminal.

[0010]

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

(First Embodiment) FIG. 1 is a cross-sectional view showing an embodiment of an image recording apparatus of the present invention. In FIG. 1, reference numeral 1 is an upper cassette for accommodating recording paper SH which is a recording material. ing. Further, below the upper cassette 1, a lower cassette 2 which also accommodates the recording paper SH is arranged, and the recording paper SH in each cassette is provided with the registration rollers 5 by the paper feed rollers 3 and 4. It will be delivered to the position. Then, the registration roller 5 conveys the recording paper SH fed from the paper feed rollers 3 and 4 or the paper refeed roller 19 to the image recording unit at a predetermined timing.

A primary charging device 6, a developing device 7, a transfer charging device 8, a cleaner device 9, and a charge eliminating lamp 10 are arranged around the photosensitive drum 11 in the image recording section. Laser unit 1 for exposing the photosensitive drum 11
2 are provided. Therefore, when the photosensitive drum 11 uniformly charged by the primary charger 6 is irradiated with laser light from the laser unit 12 via the polygon mirror 13 rotated at a constant speed by the scanner motor 13a, the photosensitive drum 11 is irradiated. Forms an image according to the image information, and this image is developed by the jumping developing method with, for example, one-component toner in the developing device 7, and is transferred onto the recording paper SH conveyed by the registration roller 5 as described above. It is transferred by the charger 8. Then, the toner remaining on the photosensitive drum 11 after the completion of the transfer is collected by the cleaner 9 by the device 9, and the photosensitive drum 11 is exposed by the charge eliminating lamp 10 to neutralize the residual charge.

Next, the recording paper SH for which the transfer process has been completed
Is conveyed to the fixing device 14, where heat and pressure are applied, and the image is fixed on the recording paper SH. Then, the recording paper SH for which the fixing process is completed is set to the flapper 1
When the recording mode is one-sided and the stacked sheet is discharged, the recording sheet SH that is transported to the exit roller 16 side and is printed by the driving of the exit roller 16 is stacked on the stack tray 23. The sheets are stacked and ejected.

On the other hand, in the case where the recording mode is single-sided and the sheet is normally discharged, the recording sheet SH is conveyed to the reversing roller 17 side by the flapper 15, and the reversing roller 17 rotates in the forward direction. Thus, the recording paper SH for which the fixing process is completed is discharged. When the recording mode is double-sided, the reversing roller 17 rotates in the forward direction to convey the recording paper SH for which the fixing process has ended, but immediately after the trailing edge of the recording paper SH has passed the reversing sensor 21, it rotates. Reverse
The recording paper SH is pulled into the machine again. The recording sheet SH that has been drawn in is relayed and conveyed by the relay roller 18 to the position where the sheet re-feeding roller 19 is disposed, and the registration roller 5 is moved as described above.
Is re-conveyed to the image recording section. Paper path sensors 20 and 22 are provided behind the fixing device 14 and in front of the re-feed roller 19, respectively, to detect the passing state of the recording paper SH.

A paper feed port for the recording paper SH (paper feed from the paper feed rollers 3 and 4 or paper feed from the repaper feed roller 19)
Is specified from the host computer 25 via the printer control device 24 described later,
When the destination is always set to the stacking tray 23, single-sided recording is performed, and the paper feed port is set to the upper cassette 1 and the lower cassette 2.
When the destination is set as the re-feed area and the designation of the sheet feed port is set as the re-feed roller 19 and the destination is set as the stack tray area, the double-sided recording is performed. . Further, the fixing device temperature is also set based on the feeding of the recording paper SH and the designation of the destination.

Next, the printer controller 24 will be described. The printer control device 24 has an interface 2
It is connected to a host computer 25 serving as an external device via 6 to receive image information and control the driving of the laser unit 12 and the like, and also collectively control the driving of each driver necessary for the printing sequence.

FIG. 2 shows the printer controller 2 shown in FIG.
4 is a control block diagram for explaining the configuration of FIG. 4, and the same components as those in FIG. 1 are designated by the same reference numerals. The main control of the printer controller 24 is, as shown in FIG.
1 equipped with M24a, RAM24b, timer 24c, etc.
Chip microcomputer (hereinafter referred to as MPU) 2
4d, and the driver of each device is connected to the MPU 24d.

First, the polygon motor drive circuit 34 is connected to the scanner motor 13a and drives the polygon mirror 13 at a constant rotation speed. Then, based on the image information input from the host computer 25 through the image processing circuit 32, the laser is modulated and emitted from the laser unit 12 through the laser driving circuit 35, and the emitted laser beam is emitted immediately before the image writing. The beam detection signal received by the detector 28 and output from the beam detector 28 is shaped by the beam detection circuit 36 to generate a horizontal synchronizing signal.

On the other hand, when a print control command is output from the host computer 25 through the image processing device circuit 32 as with the image information, the main motor drive circuit 33 outputs the print control command.
The main motor 27 that drives the photosensitive drum 11, the paper feed rollers 3 and 4, the reversing roller 17, the relay roller 18, the paper refeed roller 19 and the like shown in FIG. The static elimination lamp 10 is turned on or off, a high voltage control circuit 40 applies a predetermined high voltage to the primary charger 6, the developing device 7, and the transfer charger 8, and the fixing device control circuit 41 causes the heat roller of the fixing device 14. The surface temperature of is controlled to a predetermined temperature.

Further, the solenoid clutch 29 is driven via the solenoid clutch drive circuit 37, and the solenoid clutch 29 causes the paper feed rollers 3, 4, shown in FIG.
Driving of the reversing roller 17, the relay roller 18, the sheet re-feeding roller 19 and the like is turned on and off.

Further, through the sensor input circuit 38, FIG.
The sensor output from the sensor group 30 including the paper path sensor 20 and the reversing sensor 21 shown in FIG.

Next, the fixing device 14 in the above printer device will be described in detail. FIG. 3 shows the fixing device 14.
FIG. In FIG. 3, the fixing device 14 includes a heat roller 14 a, a pressure roller 14 b, and a heat roller 14.
A halogen heater 14c provided inside, a halogen heater 14e having a light distribution different from that of the halogen heater 14c,
Also, the halogen heater 14e and the halogen heater 14c
It is composed of a thermistor 14d for detecting the temperature of radiant heat.

An example of the light distribution of the halogen heater 14c and the halogen heater 14e is shown in FIG. As shown in this figure, the light distribution peak of the halogen heater 14c is at a position different from the peak of the halogen heater 14e. In addition,
This figure shows an example of the light distribution and is not limited to this light distribution.

As shown in FIG. 5, which is a front view, the fixing device 14 is covered with a fixing device cover 14k, and lead wires of a halogen heater are wired to the left and right of the connector 14f. With such a configuration, it is difficult to visually check the connection confirmation of the heater after the fixing device 14 is assembled, and if the connection of the heater is incorrectly connected, the fixing is not normally performed. Paper was sometimes ejected without being fixed.

Therefore, according to the present invention, the peak of the light distribution of the halogen heater is measured by a measuring instrument equipped with an optical sensor to determine whether or not the heater is properly connected. The measuring method of the present invention will be described below. First, the fixing device control circuit 41 shown in FIG. 2 will be described in detail based on FIG.

In the figure, the halogen heater 14c in the fixing device 14 is a triac 53a in the SSR 53.
Connected to the commercial power supply via. The SSR53 is a solid state relay, and is a triac 53a, LE.
D53b and a zero-cross detection circuit (not shown). When the LED 53b emits light, the triac 53a.
Is turned on to turn on the halogen heater 14c. The LED 53b has an anode connected to a DC power source through a resistor 60 and a cathode NP having a grounded emitter.
It is connected to the collector of an N transistor 57. The base of the transistor 57 is connected to the output port of the MPU 24d via the resistor 59 and the resistor 58 which are grounded. Therefore, the MPU 24d sets the output port to L (OF
In the case of F), since the LED 53b does not light up, the halogen heater 14c does not light up and the output port is set to H (O).
In the case of N), the LED 53b is turned on and the halogen heater 14c is turned on. The same applies to the method of controlling the heater 14e.

Next, FIG. 7 shows an optical sensor 10 as a light detecting means.
1 shows a measuring device 100 with 0a. Optical sensor 100a
Can be set on the heat roller 14a, and the position of the optical sensor 100a is set to the position of the light distribution peak of the halogen heater 14c.

In such a structure, the optical sensor 100a is set in advance on the heat roller 14a in the fixing device 14, a signal for turning on the LED 53a is issued from the MPU 24d, and only the halogen heater 14c is turned on. At that time, it is determined by the optical sensor 100a whether or not the halogen heater 14c is emitting light. If light emission is detected, it is determined that the connector connection is correct, and if light emission is not detected, the connector connection is incorrect.

As described above, it is possible to eliminate troubles such as discharge of unfixed paper due to erroneous connection of heaters by inspecting using light detection means for detecting light and determining heaters having different light distributions as described above. To enable.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. In the description, reference will also be made to FIG. 6 used in the first embodiment, the same parts as those in the first embodiment will be designated by the same reference numerals, and description thereof will be omitted.

In the second embodiment, the connector is constructed so as to eliminate erroneous connection between the common terminal and the non-common terminal of the halogen heater.

FIG. 8 is a diagram showing a second embodiment. This figure is a view of a connector connecting the heater in the fixing device 14, and is composed of two connectors, a connector 14f and a connector 14g.

First, the connector 14f is provided with the halogen heater 14 shown in FIG. 6 used in the description of the first embodiment.
c and only the common terminal of the halogen heater 14e are connected, and then only the non-common terminals of the halogen heater 14c and the halogen heater 14e shown in FIG. 6 are connected to the connector 14g.

By thus dividing the common terminal and the non-common terminal of the heater for each connector, it is possible to eliminate erroneous connection between the common terminal and the non-common terminal.

[0035]

As described above, according to the present invention,
By using a plurality of connectors and dividing them into a connector to which the common terminal of the heater is connected and a connector to which the non-common terminal is connected, erroneous connection between the common terminal and the non-common terminal can be prevented.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a laser printer according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a printer control device in the laser printer of FIG.

FIG. 3 is a diagram showing a fixing device in the laser printer of FIG.

FIG. 4 is a diagram showing a light distribution of a heater in the fixing device of FIG.

5 is a front view of the fixing device of FIG. 3 installed in the laser printer of FIG.

FIG. 6 is a detailed block diagram of a fixing device control circuit in the printer control apparatus of FIG.

FIG. 7 is a diagram showing a measuring device including an optical sensor according to the first embodiment of the present invention.

FIG. 8 is a front view of a fixing device according to a second embodiment of the invention.

[Explanation of symbols]

 14 Fixing device 14c, 14e Halogen heater 14f, 14g Connector 100a Optical sensor (light detecting means)

Claims (1)

[Claims] 1. An image recording apparatus having a fixing device for fixing a developer image transferred on a recording material by applying heat and pressure using a plurality of heaters having different light distributions, wherein the heater and a power source are connected. An image recording apparatus having a plurality of connectors, wherein a common terminal connected to a power line of a heater and a non-common terminal connected to a control line are separately connected to separate connectors.