JP2562212B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus having a plurality of optical systems.

[Conventional technology]

There are various image forming apparatuses that use a process of forming an image by irradiating a photosensitive material with an optical image. For example, an electrostatic latent image is formed by exposing a charged photosensitive member to an image, and the latent image is formed. There is an apparatus and the like using an electrophotographic method in which the toner is developed with toner, transferred onto paper and fixed. Further, as the image forming apparatus, in addition to the apparatus by the above method, for example, Japanese Patent Laid-Open No.
As disclosed in JP-A-88739 and JP-A-59-30537, an image is formed by destroying a photocurable microcapsule and letting a dye contained therein flow out to develop a color on an image-receiving sheet. There is a device for performing.

Such an image forming apparatus usually has a single original placing table, and an original is placed on the original placing table to copy an image. However, the above-mentioned originals include not only general sheet-shaped originals but also slide films using a transparent film. When this slide film is placed on the original placing table and copied, it is sufficient. It was difficult to obtain excellent image quality.

Therefore, a conventional image forming apparatus is disclosed in, for example, Japanese Patent Laid-Open No. 58-
As disclosed in Japanese Laid-Open Patent Publication No. 182629 and Japanese Patent Laid-Open No. 59-198442, a device for exclusive use of a film, which is composed of a Fresnel lens or a screen and a slide film projector, can be placed on a document table. is there. As a result, the image forming apparatus can obtain a good image quality by projecting a film image on the above-mentioned Fresnel lens or screen and exposing the projected image on the photosensitive material.

[Problems to be Solved by the Invention]

However, in the above-mentioned conventional image forming apparatus, when switching between a general document and a slide film, it is necessary to perform a switching operation for attaching or detaching a film-dedicated device, and especially when the switching is frequent, the switching operation is difficult. It will be a burden. Further, in the above-mentioned image forming apparatus, it is necessary to secure a storage place for the detached film-dedicated device, which makes handling of the film-dedicated device extremely inconvenient.

In view of this, Japanese Patent Laid-Open No. 182629/1983 has a plurality of document placing tables at different positions, and the switching of these document placing tables is performed by a movable type switching device arranged in the optical path between the document and the photoconductor. There is disclosed an image forming apparatus configured to perform a mirror. As a result, when the above-mentioned film-only device is attached to one of the document mounting tables, an image forming apparatus having a document mounting table for slide film and a document mounting table for general documents is provided, and the load of switching work is increased. Can be reduced. Further, in this case, it is not necessary to secure a storage place for the film-only device. However, in this image forming apparatus, since switching between the two document mounting tables is performed by changing the optical path, a high degree of positioning accuracy is required for the switching mirror that changes the optical path, and reliability during copying is reduced. Have the problem of doing.

In addition, the photosensitive material used in the image forming apparatus generally has temperature dependency in which the sensitivity characteristic to light changes depending on the temperature, and particularly when the photosensitive material is a photocurable microcapsule, curing is not performed. The amount of light to start changes sharply with temperature. As a result, in the above-described image forming apparatus, the image density and the like that are formed fluctuate due to changes in the temperature of the installation location, which makes the image quality unsatisfactory.

Therefore, according to the present invention, it is possible to easily switch a plurality of document placing tables without changing the optical path, and to provide an image forming apparatus capable of obtaining stable image quality even when the temperature at the installation location changes. It is intended to be provided.

[Means for solving the problem]

In order to solve the above-mentioned problems, an image forming apparatus according to a first aspect of the present invention uses a photosensitive member having temperature dependence in a first exposure unit by reflected light from a document passing through an independent optical path. A first exposure optical system for imagewise exposure and the photosensitive member,
A second exposure optical system that performs image exposure at a second exposure unit different from the first exposure unit by the transmitted light of the original that passes through an independent optical path different from that of the first exposure optical system; Heating the photosensitive members located in the second exposure unit collectively 1
One of the heating means and at least one of the optical systems are selected to perform the image exposure, and the heating means is operated to maintain the temperature at a predetermined temperature.

In order to solve the above-mentioned problems, an image forming apparatus according to a second aspect of the present invention uses a photosensitive member having temperature dependence in a first exposure section by reflected light from a document passing through an independent optical path. A first exposure optical system for imagewise exposure and the photosensitive member,
A second exposure optical system that performs image exposure at a second exposure unit different from the first exposure unit by the transmitted light of the original that passes through an independent optical path different from the first exposure optical system, and each of the above exposures. And heating means for individually heating the photosensitive member and corresponding at least one optical system to perform the image exposure, and heating means corresponding to the exposed portion to be image-exposed. It is characterized in that it has a control means for activating only this and maintaining it at a predetermined temperature.

[Work]

According to the first and second aspects of the invention, the image forming apparatus has the first and second exposure optical systems, for example, the first exposure optical system is used to image-expose a general document. The second exposure optical system is used to image-expose a transparent original such as a slide film. In this case, the work of attaching and detaching the film-dedicated device becomes unnecessary, and the load of the switching work can be reduced. Further, the optical paths of the respective optical systems are independent from each other, and the optical paths of the respective optical systems are not changed even when the optical systems are switched. Therefore, the image forming apparatus has high reliability at the time of copying due to the change of the optical path, and for example, it is possible to newly add another optical system to the image forming apparatus having only a single optical system. Will be done.

Further, the exposure unit for imagewise exposure is provided with a heating unit maintained at a predetermined temperature, and this heating unit heats the photosensitive member to a predetermined temperature. Therefore, the photosensitive member is always maintained at a constant temperature, and the image forming apparatus performs copying with stable image quality regardless of the temperature dependency of the photosensitive member, even if the temperature of the installation location fluctuates. Is possible.

In the image forming apparatus according to the first aspect, the photosensitive members located in the first and second exposure units are collectively heated by one heating unit. Therefore, this image forming apparatus is
It is possible to reduce the number of parts of the heating means arranged in the above-mentioned exposure section, and consequently to reduce the material cost.

On the other hand, in the image forming apparatus according to the second aspect, only the heating means corresponding to the exposed portion where the image is exposed is operated to keep the photosensitive member at the predetermined temperature. Therefore, in this image forming apparatus, the amount of electric power for operating the heating unit is minimized by limiting the photosensitive member to only the portion where the heating is required, and the running cost can be reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

In the image forming apparatus according to the present embodiment, as shown in FIG. 1, an image is formed on a transparent film and a first exposure optical system 1 used when copying a general sheet or thick original. It has a second exposure optical system 2 used when copying a translucent original 14 such as a slide film.

The first exposure optical system 1 described above includes an original placing table 3 arranged on the upper surface of the image forming apparatus, an exposure lamp 4 for irradiating the original placing table 3 with light while moving in the A direction, and an original placing table 3. A first optical unit 7 composed of a first mirror 5 that reflects the reflected light from the second mirror 6 to a later-described second mirror 6 through a slit 50, and a first optical unit 7 that moves in the A direction at half the speed of the first optical unit 7. A second optical unit 9 including a second mirror 6 and a third mirror 10, a zoom lens 11 provided with a color correction filter for correcting the color of a formed image, and a media sheet which is a photosensitive member for the light from the zoom lens 11 It is composed of a fourth mirror 13 which reflects light in the direction of the exposure portion 24a (first exposure portion) through which 12 passes.

On the other hand, the second exposure optical system 2 is disposed on the upper side surface of the image forming apparatus, holds the translucent original 14 detachably,
A holding member 18 for moving the held transparent original 14 in the B direction
An exposure lamp 15 for irradiating the transparent original 14 held by the holding member 18 with light, a blower fan 16 for cooling the exposure lamp 15, and an exposure slit for controlling the width of the light from the exposure lamp 15. 17 and a color correction filter that corrects the color of the formed image, and exposes the light transmitted through the translucent original 14 to the exposure unit 24b.
It is composed of a lens 19 which converges on the (second exposure section).

The media sheet 12 to which the light from the first exposure optical system 1 and the second exposure optical system 2 is irradiated is described in, for example, Japanese Patent Laid-Open No.
As disclosed in JP-A-88739 and JP-A-59-30539, a large number of photosensitive pressure-sensitive microcapsules containing cyan, magenta, and yellow color-forming dyes are applied on a sheet made of aluminum. It was done. The microcapsule has a property that the hardness increases when the amount of light applied is a predetermined amount or more.

The media sheet 12 is formed in a roll shape, and the winding core is attached to the media supply shaft 20 which is rotatable in the forward direction and the reverse direction, while the leading end thereof is the same as the media supply shaft 20. It is attached to a media take-up shaft 21 which is rotatable in both directions. The media supply shaft 20 and the media take-up shaft 21 are driven by a main motor via a rewinding clutch and a take-up clutch (not shown). The media supply shaft 20 and the media take-up shaft 21 are integrally provided in the media cartridge 22 and are detachably attached to the image forming apparatus together with the media sheet 12. As a result, the media sheet 12 can be immediately updated simply by replacing the media cartridge 22.

The above media cartridge 22 has a media sheet
A guide roller 23 that regulates the traveling direction of 12 is provided. Further, above the media cartridge 22, there are disposed conveying rollers 25a and 25a for guiding the media sheet 12 from the guide roller 23 to the exposure portions 24a and 24b and a guide roller 26. A slit plate 27 having the slit holes is provided. The slit plate 27 is provided with a slit sensor 28 such as a photo interrupter.
Is connected to the control means described later. As a result, the winding amount of the media sheet 12 is detected by the slit plate 27 and the sensor 28.

In the exposure parts 24a and 24b through which the media sheet 12 whose direction is regulated by the guide roller 26 passes,
A heater 29 that is a heating unit that heats 12 is provided on the side of the media cartridge 22. As shown in FIG. 2, the heater 29 has a surface facing the media sheet 12 that is larger in area than both exposed portions 24a and 24b, and is built in the heat insulating rubber 29b and the heat insulating rubber 29b. And a heater wire 29a such as a nichrome wire connected to a power source (not shown).

The heater 29 is provided with a temperature sensor 30 such as a thermistor for detecting the temperature in contact with the heat insulating rubber 29b. The temperature sensor 30 is connected to a control means, and the control means controls ON-OFF of the heater 29 on the basis of the output from the temperature sensor 30, and holds the heater 29 in a temperature range of 35 to 45 ° C. ing. As a result, the photosensitive pressure-sensitive microcapsules of the media sheet 12 are maintained at a temperature within a predetermined range, so that the temperature dependence in which the sensitivity characteristic with respect to light varies depending on the temperature is maintained constant.

Further, between the heater 29 and the media sheet 12, the traveling media sheet 12 is prevented from vibrating to prevent exposure of the exposure parts 24a and 24b.
A supporting member 31 for positioning the supporting member 31 is provided, and both ends of the supporting member 31 are close to the guide roller 26 and the guide roller 32 for changing the traveling direction of the media sheet 12 like the guide roller 26. It is formed of sheet metal, for example.

As shown in FIG. 1, the guide roller 32 is configured to change the media sheet 12 toward the pressure developing device 33. The pressure developing device 33 includes large and small pressure rollers 33a and 33b. have. These pressure rollers
33a and 33b are connected to a main motor to be driven, and at least one pressure roller 33a.
-33b is provided with a pressure release clutch (not shown). As a result, the pressure between the pressure rollers 33a and 33b is pressed and released by the pressure pressurization releasing clutch, so that the uncured microcapsules of the media sheet 12 are crushed at the time of pressurization. ing.

In addition, between the pressure rollers 33a and 33b, the color forming dye that has flowed out from the crushed microcapsules is transferred, and the image receiving sheet 34 coated with the developing material that develops the color forming dye is passed. It has become. It should be noted that this developing material is one that is usually used in a carbon-free technology, and for example, a material such as phenol aldehyde resin or phenol acetylene polycondensation resin can be used.

The image receiving sheet 34 is housed in a paper cartridge 35 that is detachably provided on the lower side surface of the image forming apparatus. Above the paper cartridge 35, the image receiving sheet 34 is provided.
A sheet detection sensor 36 for detecting the presence or absence of the sheet and a suction fan 37 for floating the image receiving sheet 34 upward are provided. Further, between the paper cartridge 35 and the pressure developing device 33,
A paper feed roller 38 with a belt for pulling out the image receiving sheet 34 from the paper cartridge 35, and the image receiving sheet 34 with the pressure roller 33a.
A timing roller 39 for feeding between 33b is provided, and these paper feeding roller 38 and dimming roller 39 are provided.
Are driven by a main motor (not shown). A trailing edge detection sensor 40 for detecting the trailing edge of the image receiving sheet 34 is provided between the paper feed roller 38 and the timing roller 39.
Is provided.

On the other hand, the image receiving sheet 34 that has passed through the pressure developing device 33 is adapted to be discharged onto the tray 48 via a sheet conveying system, and this sheet conveying system includes a conveying belt 41 and a conveying belt driven by a main motor. It has rollers 43a and 43b. Between the transport roller 43a and the transport belt 41,
A heat treatment device 44, which is also a glossing device composed of heat rollers 44a and 44b for increasing the color development speed of the color forming dye transferred to the image receiving sheet 34, is provided.
A cooling blower 45 that cools the heated image-receiving sheet 34 is disposed below. In addition, this heat treatment device 44
A paper detection sensor 46 that detects a paper jam is provided between the paper conveyance belt 41 and the conveyance belt 41, and a paper detection sensor 47 similar to the paper detection sensor 46 is also provided between the conveyance rollers 43a and 43b. There is.

The above-mentioned paper detection sensors 47 and 48 are connected to a control means, and this control means, as shown in FIG. 3, is an arithmetic processing unit (CPU) 100, an input interface 113, output interfaces 101a and 101b, and It consists of memory. The above memory comprises a ROM (Read Only Memory) 114 and a RAM (Random Access Memory) 115. The ROM 114 has set time data T ₁ , T ₂ , T ₃ , T used for image exposure. ₄ and a control program for controlling the image forming apparatus are stored. Then, this control program is a first exposure optical system 1 which performs exposure scanning to perform image exposure.
A mode and a second mode in which the second exposure optical system 2 performs exposure scanning to perform image exposure are selected and executed.

On the other hand, the RAM 115 temporarily stores a calculation data area for temporarily storing operation data used for calculation processing and information processing based on a control program and time data t ₁ for setting the operating time of each device. A time data area to be stored is formed.

In addition, one output interface 101a connected to the arithmetic processing unit 100 has an output terminal unit 117, 118, 102 to 1 that operates by an output from the arithmetic processing unit 100, such as a relay.
There are multiple 09.116. Output terminal part 117 /
Reference numeral 118 is for operating the first exposure optical system 1 and the second exposure optical system 2, and other output terminal portions 102 to 109.
Reference numeral 116 is connected to a main motor, a take-up clutch, a rewinding clutch, a paper feed roller clutch, a timing roller clutch, a suction fan 37 shown in FIG. 1, a heat treatment device 44 which is also a glossing device, and a heater 29. Is designed to operate.

Further, the other output interface 101b is connected to a display unit 111 that displays, for example, the operation mode, the number of copies, and the like. The display unit 111 is provided on the upper surface of the image forming apparatus as the operation unit 110 together with the key input unit 112,
The key input unit 112 includes, for example, a mode selection key for selecting the first exposure optical system 1 and the second exposure optical system 2, a density selection key for selecting the copy density, a number setting key for inputting the number of copies, and a copy operation key. A copy start key for instructing start and an interrupt key for instructing interrupt of copy operation are provided.

Each of the above keys is connected to the above-mentioned input interface 113, and the signal selected by each key is input to the arithmetic processing unit 100 via this input interface 113. Further, the above-mentioned input interface 113 includes input terminal units 119 to 119 connected to each sensor.
124 are provided, and these input terminal portions 119 to 124 are provided.
Are connected to the paper detection sensor 36, the rear end detection sensor 40, the paper detection sensors 46 and 47, the slit sensor 28, and the temperature sensor 30 of FIG. 1, respectively.

The operation of the image forming apparatus having the above-described structure when copying is described below with reference to the flowchart of FIG.

First, in step (hereinafter referred to as S) 1, copying conditions such as the number of copies, copying mode, and image density are selected from the number setting key, mode selection key, and density selection key of the key input unit 112 in FIG. Input as operation data. Then, these operation data are stored in the calculation data area formed in the RAM and displayed on the display unit 111. At this time, when copying a general document, the first mode is selected and the document is placed on the document table 3 shown in FIG. On the other hand, when the transparent original 14 is copied, the second mode is selected and the transparent original 14 is set on the holding member 18.
Is inserted (S1.

Next, it is determined whether or not the copy start key of the key input unit 112 has been turned ON. If not, the process waits while repeating the above determination until the copy start key is turned ON with NO. Then, if the copy start key is turned on, YES is given and S3 is executed (S2).

When the copy start key is turned on, the time data t ₁ in which 0 is substituted is stored in the time data area, and this time data t ₁ is integrated from 0 at a predetermined interval (S3). Next, an output signal is output from the arithmetic processing device 100 to the output terminal section 104, and the winding clutch connected to this output terminal section 104 is activated.
Then, the activated take-up clutch transmits the drive of the main motor to the media take-up shaft 21 and conveys the media sheet 12 in the D direction at a predetermined speed (S4).

Then, the operation data in the copy mode is extracted from the calculation data area, and it is determined whether or not the operation data is in the first mode. Then, in the first mode,
While S6 is executed as YES, when not in the first mode, S7 is executed as NO (S5).

In S6, which is the jump destination when in the first mode, the first
Exposure scanning is performed by the exposure optical system 1. That is, the first optical unit 7 travels in the A direction at a predetermined speed, and the second optical unit 9 travels in the A direction at half the speed of the first optical unit 7. The above first optical unit 7
The exposure lamp 4 irradiates the original document on the original document table 3 with electric power of 600 to 800 W, and the reflected light from the original document is reflected by the slit 50, the first mirror 5, the second mirror 6, and the second mirror 6. Three
The exposure unit 24a is irradiated with a light image through the mirror 10, the zoom lens 11, and the fourth mirror 13. As a result, the exposure section 24a, as shown in FIG.
Image exposure is performed with the slit width of 0.

At this time, the media sheet 12 to which the above optical image is irradiated
Has microcapsules encapsulating a color forming dye, and the microcapsules have a property that the sensitivity characteristic of photosensitivity varies depending on temperature. However, the exposure unit 24a ・ 2
A heater 29 is provided in 4b, and this heater 29 is
By raising the temperature of the microcapsules to a predetermined temperature, a constant sensitivity characteristic is maintained. As a result, the above-described optical image stably and selectively cures the microcapsules of the media sheet 12 even when the temperature of the installation site fluctuates, and the cured microcapsules form the formed image. A cured image with constant density and color tone is formed (S6).

On the other hand, in S4, when S7 is executed as NO which is not the first mode, the second mode is executed. That is, the time data t ₁ in which 0 is substituted in S 3 is compared with the set time data T ₂ which is the delay time for matching the tip of the cured image between the first mode and the second mode. Then, until the time data t ₁ becomes equal to or greater than the set time data T ₁ , NO
On the other hand, when the time data t ₁ becomes equal to or more than the set time data T ₁ while the above integration is repeatedly executed, S8 is executed as YES with the leading ends matched (S
7).

In S8, the exposure scanning is performed by the second exposure optical system 2.
That is, light having an electric energy of, for example, 400 to 600 W is emitted from the exposure lamp 15 to the translucent original 14 through the exposure slit 17.
At this time, the transparent original 14 is moved in the B direction at a predetermined speed by the holding member 18, and the light applied to the transparent original 14 is transmitted through the transparent original 14 as an optical image. After the lens 19
The exposure unit 24b is reached via. As a result, the exposure unit 24b
Will be imagewise exposed with the slit width of the slit 17, as shown in FIG. And the above optical image is
Media sheet heated to a constant temperature by the heater 29 described above
Twelve microcapsules are selectively cured, and the cured microcapsules form a cured image (S8).

As described above, the first mode is executed in S5 and S6, while the second mode is executed in S7 and S8, and the media sheet 12 is executed in the first and second modes. A cured image is sequentially formed on. Then, when the above-mentioned first mode or second mode is executed, S9 is executed. In this S9,
The set time data T ₁ and the integrated time data t ₁ are compared, and when it is determined that the time data t ₁ is equal to or more than the set time data T ₁ , YES is executed and S10 is executed. The set time data T ₁ indicates that the tip of the cured image formed on the media sheet 12 and the tip of the image receiving sheet 34 are the pressure developing device 33.
It is time to reach all at the same time (S9).

Then, when the time data t ₁ becomes equal to or more than the set time data T ₁ , the timing roller clutch is actuated, and this timing roller clutch transmits the drive of the main motor to the timing roller 39. The image receiving sheet 34 that has been waiting by the timing roller 39 is fed to the pressure developing device 33 (S10).

After that, the time data t ₁ in which 0 is substituted again is stored in the time data area (S11), and the rotation of the pressure rollers 33a and 33b is started (S12). Then, while the time data t ₁ described above is integrated from 0 at a predetermined interval, and setting the time data T ₃ is a time required for the leading end of the time data t ₁ and the image receiving sheet 34 reaches the pressure developing device 33 Be compared. According to this comparison result, when the time data t ₁ is less than the set time data T ₃ , the process waits while repeating the data comparison as NO, and when the time data t ₁ is the set time data T ₃ or more, When the leading edge of the image receiving sheet 34 reaches the pressure developing device 33, YES is set and S14 is executed (S13).

Then, in S14, the pressure roller clutch is turned on to pressurize the pressure rollers 33a and 33b. At this time, the media sheet 12 and the image receiving sheet 34 are pressed against each other between the pressure rollers 33a and 33b. Therefore, the above-mentioned pressurization crushes the uncured microcapsules on which the cured image of the media sheet 12 is not formed, and causes the color forming dye to flow out from the crushed microcapsules. Then, this color forming dye is used in the image receiving sheet 34.
After being transferred to, the color is developed by the developing material applied to the image receiving sheet 34 to form an image (S14).

The image receiving sheet is formed by pressing between the pressure rollers 33a and 33b.
While the image is formed on 34, the processor 100
The detection signal from the rear edge detection sensor 40 that detects the rear edge of the image receiving sheet 34 is monitored. When the above detection signal cannot be recognized, it is determined that the image receiving sheet 34 is still conveyed by the timing roller 39 and the image formation is in progress, and NO
To continue monitoring the detection signal. On the other hand, when the detection signal is recognized, it is determined that the image formation is completed after the time set by the set time data T ₄ has elapsed, and S16 is executed (S15).

In S16, the time data t ₁ in which 0 is substituted again is stored in the time data area (S16), and the set time data T ₄ is set.
And the time data t ₁ are compared. And the time data t ₁
Is greater than the set time data T ₄ , S18 is executed as YES when the transfer is completed (S17), and the pressure roller 33a
The pressure applied between 33b is released and the winding clutch is turned off.
To be. At this time, the image receiving sheet 34 is conveyed to the heat treatment device 44 by the conveyance belt 41, and is heated by the heat treatment device 44, whereby the coloring of the color forming dye is promoted and the surface is glossed. Then, the image receiving sheet 34 is a cooling blower.
After being forcibly cooled by 45, it is carried onto the tray 48 via the transport rollers 43a and 43b (S18).

On the other hand, when the rewinding clutch is turned off, 0 is assigned to the count data CT and the count data CT is stored in the calculation data area (S19). And the rewind clutch is ON
The media sheet 12 is fed back in the C direction (S20). At this time, the signals obtained by the slit plate 27 and the slit sensor 28 are integrated into the count data CT, and this integrated value is used as the amount of rewinding of the media sheet 12. Therefore, the above counting data CT
Is compared with a predetermined amount K, and when the count data CT is equal to or larger than the predetermined amount K, it is determined as YES when the rewinding is completed, S22.
Will be executed (S21). Then, in S22, the rewinding clutch is turned off, and the reverse feeding of the media sheet 12 is stopped. The predetermined amount K, which is the rewinding amount described above, is measured when the tip of the unused media sheet 12 is exposed to the exposure portion 24a.
It is set to a value slightly closer to the guide roller 26 than that (S22).

As described above, the image forming apparatus according to the present embodiment has the first exposure optical system 1 and the second exposure optical system 2, and the first exposure optical system 1 and the second exposure optical system 2 are optional. You can switch to. As a result, the image forming apparatus does not need to attach and detach the film-dedicated device when switching between a general document and a slide film, and the load of the switching operation can be reduced.

Further, the first exposure optical system 1 and the second exposure optical system 2 are
The optical paths are independent of each other, and the optical paths are not changed even when switching. Therefore, the image forming apparatus has high reliability at the time of copying due to the change of the optical path.
Further, the independent optical path makes it possible to easily add a new second exposure optical system 2 to an image forming apparatus having only the first exposure optical system 1, for example.

Furthermore, the media sheet 12 that passes through the exposure units 24a and 24b
Is heated to a predetermined temperature by a heater 29 close to the exposure units 24a and 24b, and the microcapsules of the media sheet 12 are kept at a constant temperature so that the sensitivity characteristic to light becomes stable. Has become. As a result, the image forming apparatus can always obtain stable image quality such as image density even when the temperature at the installation location changes. Further, the heater 29 is capable of reducing the number of parts by heating the media sheet 12 in a lump at both the exposure parts 24a and 24b, which in turn makes it possible to reduce the material cost.

In the present embodiment, two optical systems, that is, the first exposure optical system 1 and the second exposure optical system 2 are used, but the present invention is not limited to this, and three or more optical systems are provided. It may be.

Further, in this embodiment, as shown in FIG. 2, the media sheet 12 is collectively heated by the heater 29 in both the exposure parts 24a and 24b, but the present invention is not limited to this. For example, the exposure units 24a and 24b may be divided and heated separately.

That is, as shown in FIG. 5, the exposure units 24a and 24b are provided with heaters 62 and 60 which are heating means having an area corresponding to each of the exposure units 24a and 24b. Each of these heaters 62.6
0, similar to the heater 29 of FIG. 2, heat insulating rubber 62b, 60b
And a heater wire 62 such as a nichrome wire which is built in the heat insulating rubber 62b / 60b and connected to a power source (not shown).
It consists of a and 60a. Further, the above-mentioned heaters 62, 60 are provided with temperature sensors 63, 61 such as thermistors for detecting the temperature in contact with the heat insulating rubber 62b, 60. These temperature sensors 63 and 61 are connected to a control means, and this control means controls ON-OFF of each heater 62 and 60 based on the output from the temperature sensor 63 and 61, and the temperature is 35 to 45 ° C. It is designed to be held in the temperature range of.

Further, the above control means can individually switch ON / OFF of the heaters 62 and 60. When the first mode is executed, only the heater 62 is turned on and the media sheet is exposed at the exposure section 24a. Twelve are supposed to be heated. on the other hand,
When the second mode is executed, only the heater 60 is turned on so that the exposure section 24b heats the media sheet 12.

As a result, the image forming apparatus described above has exposure units 24a and 24b.
Since the individual heaters 62 and 60 can be independently heated, it is possible to heat the microcapsules of the media sheet 12 with a minimum amount of electric power, and it is possible to reduce the running cost. .

〔The invention's effect〕

As described above, in the image forming apparatus according to the first aspect of the present invention, the photosensitive member having temperature dependency is image-exposed in the first exposure section by the reflected light from the original document passing through the independent optical path. Image exposure of the first exposure optical system and the photosensitive member by a second exposure unit different from the first exposure unit by the transmitted light of the document passing through an independent optical path different from the first exposure optical system. Second exposure optical system, one heating unit that collectively heats the photosensitive members located in the first and second exposure units, and at least one optical system is selected to perform the image exposure. And a control means for operating the heating means to maintain it at a predetermined temperature.

Accordingly, since the first and second exposure optical systems are included, it is not necessary to perform a switching operation for attaching or detaching a film-dedicated instrument, and the burden of the exposure optical system switching operation can be reduced. In addition, the first and second
Since the optical paths of the exposure optical system are independent of each other and the optical paths of the exposure optical systems are not changed even when switching, the reliability at the time of copying due to the change of the optical path becomes high,
Further, for example, it becomes possible to newly add another optical system to the image forming apparatus provided with a single optical system.

Further, since the heating means provided in the exposure section heats the photosensitive member to maintain a constant temperature at all times, stable image quality can be obtained irrespective of the temperature dependency of the photosensitive member even when the temperature of the installation location fluctuates. It becomes possible to make a copy. further,
Since the above-mentioned one heating means collectively heats the photosensitive members located in the first and second exposure parts, it is possible to reduce the number of parts of the heating means, and consequently to reduce the material cost. It has the effect of being possible.

As described above, in the image forming apparatus according to the second aspect of the present invention, the photosensitive member having temperature dependency is image-exposed by the first exposure section by the reflected light from the original document which passes through the independent optical paths. Image exposure of the first exposure optical system and the photosensitive member by a second exposure unit different from the first exposure unit by the transmitted light of the document passing through an independent optical path different from the first exposure optical system. A second exposure optical system, a heating unit which is individually provided corresponding to each of the exposure units, and which heats the photosensitive member, and at least one of the optical systems is selected to perform the image exposure. The control means for operating only the heating means corresponding to the exposed portion to be image-exposed to maintain the temperature at a predetermined temperature.

With this, since the first and second exposure optical systems are provided, it is not necessary to perform a switching operation for attaching or detaching a film-dedicated device, for example, and it is possible to reduce the burden of the exposure optical system switching operation. In addition, the first and second
Since the optical paths of the exposure optical system are independent of each other and the optical paths of the exposure optical systems are not changed even when switching, the reliability at the time of copying due to the change of the optical path becomes high,
Further, for example, it becomes possible to newly add another optical system to the image forming apparatus provided with a single optical system.

Further, since the heating means provided in the exposure section heats the photosensitive member to maintain a constant temperature at all times, stable image quality can be obtained irrespective of the temperature dependency of the photosensitive member even when the temperature of the installation location fluctuates. It becomes possible to make a copy. further,
Since the above heating means operates only the heating means corresponding to the exposed portion to be image-exposed and maintains the predetermined temperature, it is limited to only the portion where the photosensitive member needs to be heated. It is possible to reduce the running cost by minimizing the amount of electric power to be generated.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of an image forming apparatus. FIG. 2 is a schematic configuration diagram showing an enlarged exposure unit of the image forming apparatus. FIG. 3 is a block diagram of the control means. FIG. 4 is a flowchart of the control program. FIG. 5 is a schematic configuration diagram showing an enlarged exposure unit of the image forming apparatus. Reference numeral 1 is a first exposure optical system, 2 is a second exposure optical system, 4 and 15 are exposure lamps, 12 is a media sheet (photosensitive member), and 24a and 24b.
Is an exposure unit, 29.60.62 is a heater (heating means), and 100 is an arithmetic processing unit (control means).

Claims (2)

(57) [Claims] 1. A first exposure optical system that exposes a photosensitive member having temperature dependence in a first exposure section by image light by reflected light from an original that passes through an independent optical path; A second exposure optical system that performs image exposure at a second exposure unit different from the first exposure unit by the transmitted light of the original that passes through an independent optical path different from the first exposure optical system, and the first and second exposure optical systems. One heating means for collectively heating the photosensitive members located in the exposure part of the device, and at least one of the optical systems is selected to perform the image exposure, and the heating means is operated to maintain a predetermined temperature. An image forming apparatus, comprising: 2. A first exposure optical system, which exposes a photosensitive member having temperature dependency in a first exposing section by light reflected from an original passing through an independent optical path, and the photosensitive member, A second exposure optical system that performs image exposure at a second exposure unit different from the first exposure unit by the transmitted light of the original that passes through an independent optical path different from the first exposure optical system, and each exposure unit described above. Correspondingly provided individually, heating means for heating the photosensitive member, and at least one optical system is selected to perform the above-mentioned image exposure, and only a heating means corresponding to the exposed portion to be image-exposed. An image forming apparatus comprising: a control unit that operates to maintain a predetermined temperature.