JPH01257837A - Image forming device - Google Patents

Abstract

PURPOSE:To enable printing operation in addition to copying operation and to obtain an image of high picture quality and high dignity by providing a necessary copy exposing means and an auxiliary exposing means which performs uniform exposure, and adding an energy control means between the auxiliary exposing means and a photosensitive member. CONSTITUTION:This device is provided with the copy exposing means which forms an image of an original on the photosensitive member 25, the auxiliary exposing means 11 which exposes the photosensitive member 25 directly, and the energy control means which is arranged between the photosensitive member 25 and auxiliary exposing means 11 and transmits energy emitted by the auxiliary exposing means 11 selectively to the photosensitive member 25. Then when copying operation is performed, the copy exposing means and the auxiliary exposing means 11 which is used so as to improve the quantity of the image are used and when printer operation is performed, the auxiliary exposing means 11 and energy control means are used. Consequently, both a copying function and a printing function are obtained and the image of high quality and high dignity is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image forming apparatus such as a copying machine or a printer that forms an image by applying energy to a photosensitive member. The present invention relates to a composite image forming apparatus having the following functions.

[Conventional technology]

In recent years, the information society has progressed further and a wide variety of information processing devices have been devised. Furthermore, even in images, which are the primary output format for information, high image quality, high definition, colorization, etc. are being promoted. There are many systems for forming such images, but some have been proposed that utilize a photosensitive member in which photosensitive microcapsules are formed on a substrate. An image-forming material in which the microcapsules are exposed by applying light energy and then developed by pressure (Japanese Patent Laid-Open No. 59-3053)
7, JP-A-62-232638), image forming methods using such materials (JP-A-61-219041: printer, JP-A-62-222255: copying machine), etc. can be mentioned.

[Invention or problem to be solved]

However, the image forming methods shown in the two prior art examples are only described in principle and lacking in specifics, and have only a single function as a copying machine or a printer. Furthermore, if two image forming methods are combined, it is possible to have both functions, but simply combining them will not produce an efficient image forming device, and the quality of the resulting images will not be as good. It can not be said.

The image forming apparatus of the present invention solves this problem.
The purpose is to provide an efficient image forming apparatus that has both a copying function and a printing function, and can obtain high-quality and high-definition images.

[Means to solve the problem]

The image forming apparatus of the present invention forms an image by forming a latent image on a photosensitive member in which microcapsules encapsulating a photosensitive substance are formed on a substrate, and then superimposing the latent image on a transfer member and developing the image under pressure. In the image forming apparatus, copying exposure means forms an image of a document on the photosensitive member;
It is characterized by comprising an auxiliary exposure means that directly exposes the photosensitive member, and an energy control means that is located between the photosensitive member and the auxiliary exposure means and selectively transmits the energy emitted from the auxiliary exposure means to the photosensitive member. shall be.

[Effect]

According to the above-described configuration of the image forming apparatus of the present invention, the copying exposure means and the auxiliary exposure means used to improve the quality of the image are used when performing the copying operation, and the copying exposure means is used when the printer operation is performed. By using the auxiliary exposure means and the energy control means, the above object can be achieved.

〔Example〕

The image forming apparatus of the present invention will be described in detail below according to embodiments.

FIG. 1 is a front cross-sectional view of a copying machine with a movable document table and a multifunctional color printing/printing machine showing an embodiment of the image forming apparatus of the present invention, and is divided into an upper frame I and a lower frame 2. It has a ramshell structure. First, the structure of the present image forming apparatus will be explained.

In the figure, an upper frame 1 includes an original table 3 forming a copy exposure means, an exposure illumination mechanism 4, and a cooling fan.

5.6, a cassette 7, an upper pressure roller 9 and a pinch roller 10 of the pressure developing device 8 are installed. The lower frame 2 also includes an auxiliary exposure means 11, a liquid crystal shutter array 12 as an energy control means, a rotating shaft 13, a spring 14, a heat treatment device 15, a separation mechanism 16, a semi-processing roller 17 of the pressure developing device 8, and a lower Pressure roller 18, application shaft 1
9, an application spring 20, a paper feeding mechanism 21, a transfer member container 22, an output tray 23, etc. are formed. The upper frame 2 is engaged with the rotation shaft 13 and can be rotated in the direction shown by E in the figure. When rotating upward, it is pushed up by the spring 14, and the foot portion 24 of the upper frame 1 is moved against the lower frame. It comes into contact with the bottom of 2 and is supported, and is in an open state.

A continuous band-shaped photosensitive member 25 is housed in a cassette 7, which is a photosensitive member storage container, and is mounted inside the main body. The photosensitive member 25 is attached to the supply roller 2 provided in the cassette 7.
6 and the take-up roller 27, and is fed in the direction of arrow C in the figure. Further, the transfer member 28 is in the form of a belt cut to a predetermined size, and is stacked in the transfer member storage container 22.

Note that the document table 3 is movable in the direction F in the figure with the document 29 placed thereon.

The exposure illumination mechanism 4 includes a halogen lamp 30. A refractor 31 that condenses the light beam emitted from this halogen lamp 30
, a transparent glass plate 32 provided to improve ventilation of the cooling fan 5, a heat absorption filter 33 that prevents the heat generated from the halogen lamp 30 from directly irradiating the original 29, and reflection from the original 29. It consists of an imaging lens 34 that forms an image of light onto the photosensitive member 25, a color adjustment filter 35 that adjusts the hue of the image, an exposure table 36 provided at a position where the photosensitive member 25 is exposed, and the like. Among these, the color adjustment filter 35 is yellow, magenta, cyan (
It consists of three independent glass filters that transmit the respective light rays (hereinafter referred to as Y and M1C), and the amount of light ray transmission can be adjusted by a drive mechanism (not shown).

Among the members of the exposure illumination mechanism 4 described above, the members around the halogen lamp 30 are air-cooled by a cooling fan 5.6, and the air passage is in the direction of arrow G in the figure.

Nao, rated output 800W1 for halogen lamp 30
A straight tube halogen lamp with a color temperature of 3000° is used, the amount of light is precisely controlled by a light amount control circuit (not shown) that controls the firing angle of a triac. J: 8 as the imaging lens 34
A row of fiber lens arrays are used.

As shown in FIG. 2, the auxiliary exposure means 11 includes three lamps (R lamp 40, G lamp 41, and B lamp 42) that emit red, green/blue (hereinafter referred to as R, G, and B), respectively. ), a lens group 43, a lamp cover 44 that serves as a reflector, and the like. These lamps use aperture-type cold cathode discharge tubes.
It is designed to be lit at a high frequency by an inverter circuit (not shown).

On the other hand, the liquid crystal shutter arrays 12 are arranged so as to face each of the three lamps, and by applying an appropriate voltage to the liquid crystal shutter arrays 12, transmission/non-transmission of the light rays emitted from the lamps can be controlled. It looks like this.

As the photosensitive member 25 and the transfer member 28, for example,
9-30537 can be used. Therefore, the principle of image formation using this photosensitive member will be briefly explained.

Three types of photocurable microcapsules having different wavelength sensitivity characteristics are uniformly coated on the entire surface of the base of the photosensitive member 25. Microcapsule diameter is approximately 5-20μ
m, and inside each of the three types of microcapsules,
A photocurable resin which is a photosensitive substance, a dye precursor that reacts with a color developer applied to the transfer member 28 to develop colors of Y, M, and C, and the like are enclosed. Among these, microcapsules encapsulating a dye precursor that produces a Y color are sensitive to B light, microcapsules encapsulating a dye precursor that produces a M color are sensitive to G light, and a microcapsule that encapsulates a dye precursor that produces a M color is sensitive to G light. The microcapsules encapsulating the dye precursor are sensitive to R light. Since this microcapsule is photocurable,
Since the photosensitive and hardened microcapsules are not destroyed by the pressure development device described below, the dye precursor within the microcapsules does not react with the color developer of the transfer member 28, and therefore no color is developed. On the other hand, microcapsules that do not photocure are crushed by a pressure developing device, and the dye precursor and color developer react to develop color. A desired image can be formed by selectively and appropriately applying light energy to such photosensitive portions. Further, since the amount of hardening of the microcapsules changes depending on the rate of application of light energy, the extent to which they are destroyed by pressure changes and the density of color development changes. Therefore, an image with excellent halftone reproducibility can be formed.

Next, uniform exposure for further improving the quality of the obtained image will be explained.

FIG. 3 is a graph showing an example of the photosensitive characteristics of a photosensitive member, in which the relationship between exposure energy, which is energy for curing microcapsules, and color density (0°D value) is plotted. The photosensitive properties of the photosensitive member are nothing but the photosensitive properties of the photosensitive substance encapsulated in the microcapsules.As can be seen from the figure, the effective energy range for image formation is from the minimum effective exposure dose of 1 ogE. The minimum effective exposure amount is up to 1 o g E 2 . Among these, the exposure corresponding to the minimum effective exposure amount 1 og E + is performed separately from the image exposure, or is uniform exposure. By performing the --like exposure, it is possible to reduce the apparent γ value of the upper image exposure, so it is possible to reproduce better halftones and form a high-quality image.

In addition, when forming a color image, as shown in FIG. 4, since the photosensitive characteristics of the microcapsules encapsulating dye precursors of Y, M, and C are different (range shown by area A in the figure), - It is necessary to adjust the exposure amount according to the photosensitivity characteristics of each microcapsule. Therefore, in this example, five lamps (R lamp 40, G1B) used in the auxiliary exposure means 11 as light sources for uniform exposure are used.
A lamp 41 and a B lamp 42) are used, and the amount of light emitted is appropriately set to match the minimum effective exposure m 1 o g E of each microcapsule.

Furthermore, microcapsules encapsulating each of Y, M, and C dye precursors have a minimum effective exposure dose of 1 og E .

In addition, since the maximum effective exposure amount 1 o g Ex also differs (range shown in area B in Fig. 4), it is necessary to adjust the exposure energy using the color adjustment film 35 to obtain the desired hue. .

Now, returning to FIG. 1 again, the functions of the individual components will be explained according to the process of image formation. First, the copying operation will be described.

When forming a copy image, the original 29 is first set at a predetermined position on the original platen 3, the original platen 3 moves to the starting position, stops briefly, and immediately starts moving in the opposite direction. At the same time, the supply roller 26 rotates in the direction indicated by B in the figure, and the take-up roller 27 rotates in the direction indicated by A, thereby moving the photosensitive member 25 or document table 3 by an amount corresponding to the size of the image desired to be formed. It is sent out at the same speed as the photosensitive member 25, passes over the exposure table 36, and forms a latent image of the original 29 on the photosensitive member 25. (
Image Exposure) The imagewise exposed photosensitive member 25 is then uniformly exposed by the auxiliary exposure means 11. R lamp 401G lamp 41,
The B lamps 42 are each controlled to have an appropriate brightness according to the photosensitive characteristics of the photosensitive member 25, and at this time, the liquid crystal shutter array 12 receives light emitted from the R lamp 40, the G lamp 41, and the B lamp 42. Controlled to allow all light to pass through.

The transfer member 28 is pulled out one by one by the paper feeding mechanism 21 from the start of exposure of the photosensitive member 25, and is moved in advance in the direction down in the figure by the upper fabric pressure roller 9 of the pressure developing device 8 and the semi-processing roller 1.
7, and then overlapped with the photosensitive member 25 on which a latent image has been formed by exposure.

The superimposed photosensitive member 25 and transfer member 28 are led together to a pressure developing device 8 that applies pressure to destroy the microcapsules. The pressure developing device 8 moves a semi-processing roller 17, which will be described later, in the vertical direction.
Depending on the copying operation, it is possible to select whether pressure is applied or not (pressure or non-pressure state).

Immediately after the tip of the latent image forming area of the photosensitive member 25 is fed between the upper fabric pressure roller 9 and the semi-processing roller 17, the semi-processing roller 17 is moved upward by a drive mechanism (not shown). Pressure is applied and pressure development is performed. After this,
Immediately before the end of the transfer member 28 is sent out, the semi-processing roller 1
7 moves downward, the pressure is released, and pressure development is completed. The medium processing roller 17, which has a small diameter, is placed in contact with the upper cloth pressure roller 18, backed up to prevent deformation thereof, and moved downward except during pressure development, so as to contact the upper cloth pressure roller 9. A gap is formed between them to maintain a state in which no pressure is applied. Here, 19 is an application shaft for applying pressure, and 20 is an application spring that supports it.

The photosensitive member 25 and the transfer member 28 that have come out of the pressure developing device 8 are separated by a separating device 16 that uses resin separating claws, and the transfer member 28 is heated to promote stabilization of image formation and improve quality. The image passes through a heat treatment device 15 containing a portion of the image, and is discharged onto an output image tray 23.

On the other hand, the used photosensitive member 25 is transferred to the pinch roller 10.
2, is conveyed in the direction of arrow C in the figure, and is wound up by a winding roller 27 provided in the cassette 7.

The above series of operations completes the cycle of forming one image output. The drive source for driving each of the above-mentioned mechanisms is a single motor (not shown), and power is transmitted through a wheel train, a clutch, etc. to perform predetermined operations. A tacho generator is also installed on the shaft of the motor, and is used to detect various timings, including timing detection means for selecting whether pressure is applied or not applied to the pressure developing device 8, determining the exposure amount, and controlling the exposure timing. used in decisions.

Next, the printing operation will be explained.

In the case of a printing operation, there is no need to use a copy exposure means, and the auxiliary exposure means 11 and the liquid crystal shutter array 12 are used for exposure. Therefore, the exposure illumination mechanism 4, the cooling fan 5.
6 etc. do not operate and the document table 3 does not move, but the other mechanisms operate in the same manner as in the copying operation described above.

First, the photosensitive member 25 is exposed to light energy from the auxiliary exposure means 11 while being fed in the direction of arrow C in FIG. At this time, the R lamp 40 is used so that the exposure energy becomes the maximum effective exposure amount 1 o g E 2 or more shown in FIG.
, G lamp 41, and B lamp 42 are turned on. At this time, a color latent image can be formed on the photosensitive member 25 by appropriately and selectively driving the liquid crystal shutter array 12 using an external signal in accordance with the movement timing of the photosensitive member 25. The liquid crystal shutter array 12 used a dot matrix LCD. The photosensitive member 25 on which the latent image has been formed is transferred to the transfer member 28 in the same way as in the copying operation.
After being superimposed and pressure developed, the image is outputted onto the transfer member 28 as an image.

The operations of the various mechanical sections described above are all controlled by a control system, which is not shown in the block diagram of FIG. To briefly explain this, the control system includes a central processing unit 70 (CPTJ) that is the core of the entire control system, a ROM 71 that stores control programs, and a RAM that is a program work area.
7' 2 , an external signal processing circuit 73 for processing image signals input from the outside, an interface circuit 74, a tacho generator 75 used as a reference timing, and the like. The InnoTurf Ace circuit 74 includes a motor 76 that is a driving source for the operation of the mechanism, a driver for lighting the lamp of the auxiliary exposure means 11, a driver for the liquid crystal shutter array 12, and drivers such as a solenoid and a clutch (not shown). This is a circuit for interfacing with various elements constituting the image forming apparatus of this embodiment, such as a photo ink clubter, various sensor circuits such as a microswitch, and the like. The various mechanical units described above operate in sequence according to a preset program.

Furthermore, switching between the copying operation and the printing operation may be made so that the operator can select it using an operation switch, or the above-mentioned method may be used so that the printing operation is automatically performed only when an image signal is sent from the outside. It may also be configured by a control system.

In the above description, a liquid crystal shutter array is used as the energy control means, but the present invention is not limited to this. For example, a mechanical microshutter operated by electric force or the like may be used.

Furthermore, the auxiliary exposure means is not limited to that of this embodiment, and for example, a laser scanning optical system may also be used. In this case, by selectively driving the laser, there is no need to separately provide energy control means such as a liquid crystal shutter array.

Further, although uniform exposure is performed using the auxiliary exposure means during copying operations, the invention is not limited to this; for example, the auxiliary exposure means may be used to adjust the color density and tone of the image. good.

Furthermore, in the examples given above, we have explained the photosensitive characteristics of the photosensitive member by taking as an example a material that is sensitive to visible light. This is because the forming device was taken away. However, the image forming apparatus of the present invention is not limited to this, and can be used, for example, as a copying machine with a fixed manuscript table, or as a facsimile machine.
It can be applied to a wide range of applications without being limited to visible light, as long as it forms images, such as filing systems.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a copying exposure means necessary for a copying operation and an auxiliary exposure means for performing uniform exposure, and an energy control means is added between the auxiliary exposure means and the photosensitive member. By doing so, it is possible to perform a printing operation in addition to a copying operation, and moreover, it is possible to obtain an image of high image quality and quality with excellent reproducibility of halftones.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view schematically showing an embodiment of the present invention. FIG. 2 is a schematic diagram of the auxiliary exposure means/energy control means. FIG. 3 is a diagram showing the photosensitive characteristics of the photosensitive member. FIG. 4 is a diagram showing variations in photosensitive characteristics of photosensitive members. , Figure 5 is a block diagram of the control system. 4...Exposure illumination mechanism 11... Auxiliary exposure means 12...Liquid crystal shutter array 25...Photosensitive member 28...Transfer member that's all Applicant: Seiko Epson Corporation Agent Patent attorney Suzumoto Kisanbe and 1 other person 0- ○ Police officer 2 Δq has entered the industry a lot. 72,-RAM 76, ° Narc

Claims (1)

[Scope of Claims] An image forming apparatus that forms an image by forming a latent image on a photosensitive member in which microcapsules encapsulating a photosensitive substance are formed on a substrate, and then superimposing the latent image on a transfer member and developing the image under pressure. , copy exposure means for forming an image of the original on the photosensitive member;
auxiliary exposure means that directly exposes the photosensitive member; and energy control means that is located between the photosensitive member and the auxiliary exposure means and selectively transmits energy emitted from the auxiliary exposure means to the photosensitive member. An image forming apparatus comprising: