JPH041550Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention relates to a heat retention device for a copying machine, and more specifically, to a heat retention device for a copying machine used for preventing dew condensation on an optical system.

<Prior art> Conventionally, copiers have had the disadvantage that when left in high humidity for a long time, the fluidity of powder toner decreases and uneven development occurs. If this occurs, water droplets may adhere to the lenses, mirrors, etc. of the optical system, or water droplets may mix with the powder toner in the developing section, making it impossible to perform normal copying operations, especially regarding the latter problem. Eliminates the inconvenience that cannot be solved simply by raising the internal temperature of the copying machine and leaving it for a long period of time; it inevitably requires work such as removing water droplets from lenses and mirrors, replacing powder toner, etc. In order to achieve There was a heat insulating device with a configuration (which energized the heating element).
(See Publication No. 95356).

<Problems that the invention aims to solve> A heat retention device with the above structure can definitely solve the above problems, but it requires a special heating element to be installed, which increases the cost. There's a problem.

This idea was made in view of the above problems, and it is designed to control the internal temperature when the copying machine is in an inoperable state to a temperature that can reliably prevent any negative effects on the copying machine. It is an object of the present invention to provide a heat retaining device for a copying machine that can suppress cost increases.

<Means for solving the problem> In order to achieve the above-mentioned purpose, the heat insulating device of this invention has a heating element installed at a predetermined position to insulate the parts to be kept warm inside the copying machine, and a DC motor and The heating element described above is connected in series, and when the copying machine is in an operable state, the DC motor and the heating element are energized so that the heating element functions as an external resistance for the DC motor, and the copying machine becomes inoperable. In this case, it has a main switch that energizes only the heating element.

<Function> The heat retention device with the above configuration has the main switch
By operating the copier in such a way that it cannot operate, only the heating element is energized.
It is possible to heat and raise the temperature of heated parts such as optical systems, and by operating the main switch in the opposite manner to the above, it is possible to energize the series circuit between the heating element and the DC motor, so that the heating element Since it acts as an external resistance for the motor, the copying operation can be performed by operating the DC motor.

<Examples> Hereinafter, examples will be described in detail with reference to the accompanying drawings showing examples.

FIG. 3 is a schematic diagram showing the internal mechanism of the copying machine. The interior of the copying machine main body 1 having a contact glass 11 on the top surface is divided into an upper chamber 17 and a lower chamber 18 by a partition plate 16. It has an optical system 2 and a heating element 5 made of a cement resistor, etc. inside, and also has a copy processing section 3 and a copy paper conveyance section 4 inside a lower chamber 18.

To explain in more detail, the optical system 2 includes a light source 21, reflecting mirrors 22, 23, 24, a lens 25,
and a reflecting mirror 26, by moving the light source 21 and the reflecting mirror 22 together at a predetermined speed, and moving the reflecting mirrors 23 and 24 in the same direction at half the above speed, A document tightly fixed onto the contact glass 11 by a document presser 12 can be exposed.

The copy processing section 3 has a structure in which a charging charger 32, a developing device 33, a transfer charger 34, a separation charger 35, and a cleaner 36 are arranged in this order around a photosensitive drum 31 that rotates in one direction. An electrostatic latent image is formed by forming an original image on the surface of the photoreceptor drum 31 that is uniformly charged by the charger 32, the toner image is visualized by the developing device 33, and the toner image is transformed by the transfer charger 34. , transferred onto the copy paper conveyed by the copy paper conveyance section 4, and transferred to the separation charger 35.
The copy paper is peeled off from the photosensitive drum 31 by this operation.

The copy paper conveyance section 4 includes paper feed rollers 41, 4.
2. The registration roller 43, the conveyor belt 44, the fixing device 45, and the ejection roller 46 are arranged in this order, and by selectively operating the paper feed rollers 41 and 42, the manual feed stand 13 or the paper feed cassette 14 is The copy paper is fed into the copy processing section 3 by the registration roller 43 in synchronization with the leading edge of the electrostatic latent image, and then transferred to the separation charger 35.
The copy paper peeled off from the photosensitive drum 31 is conveyed by a conveyor belt 44 to a fixing device 45 to fix the toner image thereon, and thereafter can be discharged onto a tray 15 by a discharge roller 46.

FIG. 1 is an electrical circuit diagram showing the configuration of the heat retention device, which includes a control board 51 having a CPU, memory, I/O ports, etc., and a DC current 52 that receives a commercial AC power source as input and outputs the necessary DC voltage. have. To explain in more detail, a heating element 5a is placed between a predetermined output terminal of the DC power supply 52 (in the case of the figure, the 24V terminal) and the I/O port of the control board 51,
A DC motor 53 such as a stepping motor is connected in series. A heating element 5b is also provided between the heating element 5a and a normally closed terminal of a main switch 54, such as a seesaw switch, whose switching terminal is connected to the ground terminal of the DC power supply 52 and a predetermined terminal of the control board 51. are connected. still,
The normally open terminal of the main switch 54 is connected to the I/O port of the control board 51.

With the above configuration, when the main switch 54 is operated to disable the copying operation, the series circuit of the heating elements 5a and 5b can be energized, and the inside of the upper chamber 17 can be energized. Since the temperature rises, even if the copying machine is kept in a state in which copying cannot be performed for a long time, the inside of the upper chamber 17 becomes below the dew condensation point, and the reflecting mirrors 22, 23, 2
Inconveniences such as dew condensation occurring on the lenses 4, 26 or the lenses 25 can be reliably prevented. In this case, since the heating element is divided into two parts, it is possible to keep a wide area warm, but by attaching the divided heating elements at different locations,
It is also possible to keep two places warm.

In addition, when the main switch 54 is operated to put the copying machine into a state in which copying operations can be performed, the series circuit of the heating element 5a and the DC motor 53 can be energized, and in this case, the heating element 5a acts as an external resistance for the DC motor 53, and by operating the DC motor 53 with a normal applied voltage and driving each component of the copying machine, a copying operation can be performed. Note that, for example, if the DC motor 53 is a stepping motor, a large torque can be obtained by applying a large voltage (for example, 24V) to a low-rated motor (for example, 12V) via an external resistor. , This allows the copying operation to be performed stably. When the main switch 24 is operated to enable the copying machine, the upper chamber 17 is kept warm mainly by heat generated from the light source 21, DC motor 53, DC power supply 52, and the like.

FIG. 2 is an electric circuit diagram showing another embodiment,
The only difference from the above embodiment is that only one heating element is used, and the other parts are the same.

Therefore, in the case of this embodiment, only one relatively narrow area can be kept warm.

Note that this invention is not limited to the above-mentioned embodiments; for example, the number of heating elements may be three or more,
The resistance of the heating element connected in series with the DC motor is
It is possible to set the optimum resistance value as the external resistance of the DC motor and ensure sufficient heat generation from other heating elements, and various designs can be made without changing the gist of this invention. It is possible to make changes.

<Effects of the invention> As described above, this invention uses the heating element as an external resistor of the DC motor, so it is possible to effectively keep certain parts of the copying machine warm by energizing only the heating element. In addition, the DC motor can be operated with a normal applied voltage during copying operations, and the heating element also serves as an external resistor, thereby saving space and reducing costs. It has practical effects.

[Brief explanation of the drawing]

Fig. 1 is an electrical circuit diagram showing one embodiment of the heat retention device, Fig. 2 is an electrical circuit diagram showing another embodiment, and Fig. 3 is an electrical circuit diagram showing another embodiment.
The figure is a schematic diagram showing the internal mechanism of a copying machine. 5, 5a, 5b...heating element, 53...DC motor, 54...main switch.

Claims (1)

[Scope of utility model registration request] A heating element is installed in a predetermined position to keep the parts inside the copying machine warm, and the heating element is connected in series with the DC motor, and when the copying machine is ready for operation, the DC motor and the heating element are A copying machine characterized by having a main switch that supplies power to the heating element to function as an external resistance of the DC motor, and supplies power to only the heating element when the copying machine is in an inoperable state. Heat retention device.