JPH03131841A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain a picture having stable quality without the influence of ambient temperature by detecting either the surface temperature or environmental temperature of a photosensitive recording medium, and adjusting exposure time according to the detected temperature. CONSTITUTION:A circuit adjusting the exposure time is composed of a sensor 22 which detects at least one of temperature and humidity, a transistor 24 which amplifies a signal from a sensor 22 and a motor 23 which drives an original platen glass. In this case, as the base current of the transistor 24 becomes larger, the exposure time is shortened. On the contrary as the base current becomes smaller, the exposure time is prolonged. Thus, as the sensitivity of a photosensitive is reduced, the output current from the sensor 22 becomes larger to prolong the exposure time. As the sensitivity is improved, the exposure time is shortened so as to increase the output current. Thus, picture reproducibility can be stably obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus that forms an image on a recording medium.

[Prior Art] Conventionally, this type of image forming apparatus irradiates a document with light and forms an image of the reflected or transmitted light on a photosensitive recording medium through an optical system such as a mirror filter or a lens. do,
A device configured to form a latent image on the photosensitive recording medium is known.

[Problems to be Solved by the Invention] However, in the image forming apparatus using the photosensitive pressure sensitive recording medium proposed in U.S. Pat. , it is already known that their sensitivities are different. Therefore, when used as a recording medium in a copying machine or the like, it is difficult to obtain the same image due to changes in temperature and humidity.

Furthermore, even if the temperature and humidity are the same, the heat from the light source changes the surrounding temperature and humidity, which changes the sensitivity of the photosensitive and pressure sensitive recording medium, making it impossible to obtain stable images.

The present invention has been made to solve the above-mentioned problems, and by using means for detecting at least one of temperature or humidity and means for adjusting exposure time, it is possible to influence the ambient temperature and humidity. The purpose is to obtain images of stable quality without being affected by

[Means for Solving the Problems] In order to achieve this object, one aspect of the present invention is to provide a means for detecting the surface temperature of a photosensitive recording medium or an environmental temperature, and adjusting the exposure time based on the detected temperature. and means to do so.

Another aspect of the present invention is to include means for detecting the environmental humidity of the photosensitive recording medium, and means for adjusting the exposure time based on the detected humidity. The temperature detection means and the humidity detection means may be used together.

[Function] According to the image forming apparatus configured as described above, when the surface temperature of the photosensitive recording medium or the environmental temperature is detected to be high, the exposure time is shortened, and conversely, when the temperature is detected to be low, the exposure time is shortened. becomes longer. Therefore, even if the sensitivity characteristics of the photosensitive recording medium change depending on the ambient temperature, exposure can proceed with an appropriate exposure time depending on the ambient temperature. On the other hand, the same is true when detecting the environmental humidity of a photosensitive recording medium; if the environmental humidity is high, the exposure time will be short; conversely, if the humidity is low, the exposure time will be long; Exposure continues.

[Embodiment] A description will be given with reference to FIG. 1, which shows a schematic configuration of an embodiment of a photosensitive pressure-sensitive copying machine that is capable of full-color copying.

The photosensitive and pressure sensitive copying machine 1 of this embodiment uses photosensitive paper consisting of light and pressure sensitive paper (microcapsule paper) and color developer paper. A movable document table glass 2 and document table cover 3 are provided on the top plate of the copying machine 1, and a desired document 4 is set face down on the document table glass 2.

A light source using a halogen lamp 5 or the like is installed in the upper part of the copying machine 1, and it irradiates light in a line through a slit hole provided on the top surface of the machine toward the document table glass 2, and emits light from the halogen lamp 5. The fallen light passes through the transparent document table glass 2 and is reflected by the document 4 placed thereon.

Therefore, exposure scanning of the original 4 is performed by moving the original platen glass 2. The light reflected from the original 4 is
The light passes through a filter 6 for adjusting the color tone of the copied image and enters a projection lens 7, and the light projected by this lens 7 is directed by a pair of reflection mirrors 8 and 9 and positioned along an exposure table 10. An image is formed on the microcapsule paper 11. The reflecting mirror 8.9 is mounted on a mirror mounting plate, and the optical path length and focus are adjusted by finely adjusting the position of the mirror mounting plate.

On the other hand, a long microcapsule paper 11 is wound around a cartridge shaft 12 and housed in a removable cartridge, and one end of the paper is wrapped around a cartridge shaft 12.
4a, 14b, 14c, pressure developing device 13, and separation mechanism 1
4d and reaches the winding shaft 15. That is, the microcapsule paper 11 coming out from the lower part of the cartridge is guided by the feed roller 14a1 and the guide roller 14b to the exposure table 1.
After passing under the pressure developing device 13, the microcapsule paper 11 that has passed through the pressure developing device 13 is guided to the feed roller 14c1 separation mechanism 14d and meandering adjustment roller 14e, and then wound up. It is wound up on the shaft 15. Note that the unexposed microcapsule paper 11 after leaving the cartridge is maintained in an unexposed state by the light shielding cover.

In addition, the transport speed of the microcapsule paper 11 is controlled to be constant and is made to match the moving speed of the document platen glass 2, so that the microcapsule paper 11 contains the document when passing through the exposure table 10. Latent images of predetermined lines are sequentially formed.

A paper feed cassette 17 containing developer paper (recording paper) 16 constituting a paper feed device is installed below the pressure developing device 13, and a suction cup-type paper feed mechanism that sucks paper using negative pressure suction is installed. 18 is provided, and the developing paper 16 is fed to the paper feeding mechanism 1.
8, the paper is taken out one by one and conveyed by the feed roller 19a1, the pinch roller 19b, and the developing paper roller 19c,
After the leading end is aligned by the resist gate 19d and the resist gate 19e, it is carried into the pressure developing device 13.

In this way, the pressure developing device 13 contains the microcapsule paper 1.
1 and developer paper 16 are supplied in close contact with each other and integrated, and the microcapsules on which the latent image of microcapsule paper 11 is formed and the developer coated surface of the developer paper 16 come into contact with each other on the inside. In this state, the roller 13 is held together between the small diameter roller 13a and the backup roller 13b, and pressure is applied thereto. This pressure destroys the unexposed microcapsules and forms an image on the color developing paper 16.

After the microcapsule paper 11 and the color developer paper 16 that have come out of the pressure development device 13 are separated by a separation mechanism 14d, the color development of the color developer paper 16 is promoted by the heat roller 20a of the heat fixing device 20, and an image is formed. After that, the paper is delivered to a paper ejection tray 21 by a paper ejection roller. The separated microcapsule paper 11 is wound onto the winding shaft 15 via the meandering adjustment roller 14e.

Next, a block diagram of an actual control circuit is shown in FIG. 2 and explained. A sensor 22 that detects at least one of temperature or humidity, a transistor 24 that enhances the signal from the sensor 22, and a transistor 24 that drives the original platen glass 2. motor 23
This constitutes a circuit that adjusts the exposure time.

In this case, if the base current of the transistor increases,
As the exposure time becomes shorter and, conversely, the base current becomes smaller, the exposure time becomes longer. In this way, when the sensitivity of the light-sensitive and pressure-sensitive paper decreases, the output current from the sensor is decreased to lengthen the exposure time, and when the sensitivity improves, the output current is increased to shorten the exposure time. Do it like this.

For example, the optimal conditions are 30°C to 40°C and humidity 40% to 70°C.
% photosensitive pressure-sensitive paper, sensitivity deteriorates at high temperature and high humidity. In this case, when the ambient temperature of the photosensitive pressure sensitive paper increases, the exposure time is increased to compensate for the decrease in sensitivity. In this way, even if the sensitivity of the photosensitive and pressure sensitive paper changes due to changes in the ambient temperature and humidity of the photosensitive and pressure sensitive paper, it is absorbed by changes in exposure time, so stable image reproducibility is achieved.

Further, although photosensitive pressure sensitive paper is used as the recording medium in the above-described embodiments, the same effect can be obtained even if other photosensitive pressure sensitive recording media or photosensitive media are used.

It goes without saying that the present invention can be applied not only to the reflective type surface exposure copying apparatus as in the above embodiment, but also to a reflective type slit exposure type copying machine, a transmission type copying apparatus, or other image forming apparatuses.

[Effects of the Invention] As detailed above, changes in the sensitivity of the light-sensitive and pressure-sensitive paper due to ambient temperature and humidity are adjusted by controlling the exposure time, so stable image reproducibility can be obtained.

[Brief explanation of the drawing]

1 and 2 show an embodiment embodying the present invention. FIG. 1 is a schematic configuration diagram of the entire device, and FIG. 2 is a control block diagram. In the figure, 1 is a copying machine, 11 is a microcapsule paper, 22 is a sensor, and 23 is a motor. No.

Claims (1)

[Claims] 1. In an image forming apparatus that exposes a photosensitive recording medium to light from a light source and records an image on the photosensitive recording medium, the surface temperature of the photosensitive recording medium or the environmental temperature is detected. An image forming apparatus comprising: a means for adjusting an exposure time according to the detected temperature. 2. In an image forming apparatus that exposes a photosensitive recording medium to light from a light source and records an image on the photosensitive recording medium, there is provided a means for detecting the environmental humidity of the photosensitive recording medium, and an exposure time determined by the detected humidity. An image forming apparatus comprising: means for adjusting.