JPS63125928A - Thermal copying device - Google Patents

Abstract

PURPOSE:To obtain a print having no irregularity by detecting the quantity of light from a xenon lamp and controlling it to a constant quantity at all times. CONSTITUTION:An energy control circuit 23 compares information from a storage part 22 with the output of an integrator 21 and sends a light emission stop signal to a light emission stopping circuit 24 when they become equal in value to each other. The light emission stopping circuit 24 when receiving the light emission stop signal cuts off a current flowing to the xenon flash lamp 15 to stop light emission. Here, an applied voltage is held constant to perform light emission on the best conditions at all times, and the light emission time is controlled to control light emission energy. Consequently, the light emission is performed with good efficiency at all times and the power consumption is reducible. Further, the xenon flash lamp varies in the quantity of light emission with the lamp temperature and with, so the quantity of light emission is detected directly to control the energy, thereby taking an invariable stable copy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal copying apparatus that presses a copy original and a material to be copied and performs thermal copying by light irradiation from an exposure light source. It's about control.

2. Description of the Related Art In recent years, image forming devices using light beams, called thermal copying devices, have been frequently used in electronic flash discharge tube plate making machines, 014P manuscript preparation machines, and the like.

A conventional thermal copying recording device is, for example, disclosed in Japanese Patent Application Laid-Open No. 53-121.
As shown in Publication No. 637, it was as shown in Fig. 5.

In FIG. 5, 41 is an original to be copied, and 42 is a material to be copied. Reference numeral 43 denotes a rotatably supported tubular exposure roller made of a transparent member, and inside this exposure roller 43 a reflecting mirror 44 and a xenon flash lamp 45 are arranged. Further, the rubber roller 46 is connected to the exposure roller 4
3 to bring the copy original 41 and copy material 42 into close contact. The rubber roller 46 rotates to feed the overlapping copy original 41 and copy material 42.

Every time the copy original 41 and copy material 42 that are in close contact with each other are fed a predetermined length, the xenon flash lamp 45 emits light, generates heat according to the pattern of the copy original 41, and the pattern is copied onto the copy material 42.

Problems to be Solved by the Invention However, in such a thermal copying apparatus that forms a temperature difference pattern by irradiating light and performs thermal copying, even if a xenon flash lamp provides constant energy, the amount of light changes depending on temperature changes.

The amount of light also changes with time.

Therefore, unless the energy given to the xenon flash lamp is adjusted depending on the conditions of use, there will be unevenness in the amount of light and there will be a problem in that it will not be possible to make copies with constant printing quality.

In view of the above-mentioned problems, the present invention provides a thermal copying apparatus that detects the light intensity of a xenon flash lamp and controls the light intensity so that the light intensity is always constant, thereby enabling uniform printing.

Means for Solving the Problems In order to solve the above problems, the thermal copying apparatus of the present invention has the following features:
A holding member for holding a copy original and a material to be copied, a light source for performing thermal copying by light irradiation, a light amount detection means for detecting the amount of light emitted from the light source, and a light amount detecting means for detecting the amount of light emitted from the light source until the total amount of light emitted from the light source reaches a predetermined value. The device is equipped with a light emission control means for stopping the light emission when the light emitted from the light emitting device reaches a certain temperature.

Effect of the Invention With the above-described configuration, the present invention detects the amount of light emitted by the light source and can always make copies with a constant amount of light, making it possible to always make high-quality copies even when usage conditions change. Become.

EXAMPLE Hereinafter, a thermal copying apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a transfer section of a thermal copying apparatus according to a first embodiment of the present invention. In Figure 1, copy manuscript 1
) and recording paper 12 are supported by rollers 13, and glass plate 1
4, they are pressed against the roller 13 with a predetermined force and are brought into close contact with each other. A xenon flash lamp 15, which is an exposure light source, faces the glass plate 14 in the vicinity, and a reflecting mirror 16 is arranged around the xenon flash lamp 15. Further, a detector 17 for detecting temperature is attached to the glass plate 14. A light receiving element 18 for detecting the amount of light emitted from the xenon flash lamp 15 is attached to the reflecting mirror 16.

As shown in FIG. 2, the copy original 1) has an aluminum vapor-deposited layer 1)b provided on one side of a transparent sheet 1)a, and a hot-melt ink llc coated on the other side. The aluminum vapor deposited layer 1)b is then removed in accordance with the pattern to be copied. The copy document 1) has its surface coated with the thermofusible ink IIc overlapped with the recording paper 12.

FIG. 3 shows the light emission control section of the xenon flash lamp 15, which includes a capacitor 19 for storing energy given to the xenon flash lamp 15, a charging circuit 20 for charging the capacitor 19, and an output signal of the light receiving element 18. an integrator 21 that integrates the output of the integrator 21 and a storage unit 22 that stores information on the amount of energy required for copying corresponding to the temperature detected by the temperature detector 17; An energy control circuit 23 that compares the outputs and issues a light emission stop signal when they reach the same value, and a light emission device that receives the light emission stop signal from the energy control circuit 23 and cuts off the current flowing to the xenon flash lamp 15 to stop light emission. It consists of a stop circuit 24 and a trigger voltage generator 25 that generates a high voltage signal to start the xenon flash lamp 15 emitting light.

The operation of the thermal copying apparatus configured as described above will be explained.

The copy original 1) and the recording paper 12 are held on top of each other on the roller 13, and the glass plate 14 brings the copy original 1) and the recording paper 12 into close contact with each other with a predetermined force.
When the light is emitted, the light passes through the parts of the copy document 1) where the aluminum evaporation layer 1)b has been removed, and the aluminum evaporation layer 1) 1b is removed.
The remaining portion reflects light, so heat-melt ink li
The material e receives light according to the pattern, generates heat, melts, and is transferred to the recording sleeve 12.

The copy original 1) and the recording paper 12 are continuously fed by the rotation of the roller 13. The glass plate 14 is supported at a predetermined position, and the copy original 1) advances while sliding on the surface of the glass plate 14. And copy manuscript 1) and recording paper 12
Each time the paper is sent a predetermined length, light is emitted and a copy is made.

The charging circuit 20 boosts and rectifies the AC power supply to the capacitor 1.
9 and completes charging when it reaches a predetermined voltage.The energy control circuit 23 uses the temperature information detected by the temperature detector 17 to transfer energy necessary for copying corresponding to the temperature to the storage unit 22. Call it up and decide the amount of light you need.

When the trigger voltage generator 24 receives a light emission command from a main control section (not shown), it generates high voltage and starts discharging the xenon flash lamp 15.

Then, the amount of light emitted from the xenon flash lamp 15 is detected by the light receiving element 18, and the output thereof is integrated by the integrator 21.

The energy control circuit 23 compares the information from the storage section 22 and the output of the integrator 21, and sends a light emission stop signal to the light emission stop circuit 24 when they become the same value. When the light emission stop circuit 24 receives the light emission stop signal, it cuts off the current flowing through the xenon flash lamp 15 and stops light emission.

Since the heat capacity of the copy original 1) is smaller than that of the glass plate 14, it reaches the same temperature as the glass plate 14 from when it comes into contact with the glass plate 14 until the xenon flash lamp 15 emits light. Therefore, the light emission control circuit 23 determines the copying energy based on the temperature of the glass plate 14 rather than the temperature of the copy original 1).

The higher the temperature of the copy document 1), the less heat is required to heat the ink to its melting point, and therefore the less energy is required for copying. Therefore, the storage unit 22 is preset so that the higher the temperature, the less copying energy is required. In addition, the amplification degree of the output of the integrator 21 is adjusted to finely adjust the amount of emitted energy to increase the density of the copy.
The lightness can be adjusted.

FIG. 4 is a diagram showing the operation of the energy control circuit 23. FIG. 4 fa+ shows the amount of light emitted from the xenon flash lamp 15, and FIG.
1 output voltage is shown. When light emission starts, the light receiving element 18 receives light and outputs an output proportional to the amount of light received, and the output voltage of the integrator 21 gradually increases. When the output voltage reaches voltage V1 determined by information from the storage unit 22 corresponding to the temperature of the glass plate 14 detected by the temperature detector 17, the current of the xenon flash lamp 15 is cut off, and at the same time, the integrator 21 is reset. Ru. Temperature detector 17
When the temperature of the glass plate 14 detected is high, less energy is required for copying, so a small amount of energy is stored in the storage section 22. Therefore, as shown by the broken line in the figure, when the output of the integrator 21 becomes a voltage (2) lower than (1), the current of the xenon flash lamp 15 is cut off.

In this way, by directly detecting the amount of light emitted from the xenon flash lamp 15 and controlling the light emission, the copying energy can be controlled.

The luminous efficiency of a xenon flash lamp changes depending on the gas pressure of the xenon gas sealed inside and the applied voltage. Therefore, if the luminous energy is controlled by changing the charging voltage of the capacitor, the luminous efficiency may be lowered due to the use of non-optimal luminous conditions. Therefore, if you keep the applied voltage constant, always emit light under optimal conditions, and control the emission energy by controlling the emission time,
Efficient light emission can be performed at all times, and power consumption can be reduced. Further, since the amount of light emitted by a xenon flash lamp changes depending on the lamp temperature and changes over time, by directly detecting the amount of light emitted and controlling the energy, stable copying can be performed at all times.

As described above, according to this embodiment, by controlling the transfer energy according to the temperature of the glass plate that the copy document is in contact with, the copy document is always transferred with the optimum transfer energy even if the room temperature or the temperature of the device changes. This makes it possible to obtain good printing without any unevenness.

In the example, the copy original was a sheet that transmits light according to the pattern, but a general original was used as the copy original, and a heat-sensitive color-forming transparent sheet was used as the copying material, and the colored parts of the general original were made to generate heat. A transparent sheet with angry heat color development may be used to color the transparent sheet, and the glass plate and the material to be copied may be placed in contact with each other. Transparent members such as the above may also be used.

Further, in the embodiment, the light emission control circuit stops energizing the xenon flash lamp, but this may be done by passing current through a bypass circuit to stop light emission. Also,
The mounting position of the light emitting element is not limited to the position shown in this embodiment.The amplification factor of the integrator can be adjusted to finely adjust the amount of light emitted energy to adjust the darkness and darkness of the copy. However, this may be done by adjusting the information in the storage section using an amplifier, or by storing the amount of energy corresponding to each of dark and light in the storage section.

Effects of the Invention As described above, according to the present invention, since the amount of light emitted is directly detected and the light emission energy of the light source is controlled, it is possible to perform copying with the optimum copying energy even if the usage conditions change. Good copies can always be made. Furthermore, it becomes possible to perform copying with optimum copying energy depending on the temperature of the copy document, and it becomes possible to always obtain copies with good print quality, which is extremely useful.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a transfer section of a thermal copying apparatus according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of a copy document, and FIG. 3 is an explanatory diagram of a light emission control section of an exposure light source of a thermal copying apparatus. , FIG. 4 is an operational diagram of the light emission control circuit, and FIG. 5 is a sectional view of a conventional thermal copying apparatus. 1)... Copy original, 12... Print paper, 13... Roller, 15... Xenon flash lamp, 18... Light receiving element , 19・
...Capacitor, 20...Charging circuit, 2
1...Integrator, 22...Storage section, 23
... Energy control circuit, 24 ... Light emission stop circuit, 25 ... Trigger voltage generator. Name of agent: Patent attorney Toshio Nakao and one other person Figures 1-2 Figure 3 Figure 4 JP-A Figure 5

Claims (2)

[Claims] (1) A holding member that holds a copy original and a material to be copied, a light source for performing thermal copying by light irradiation, a light emission control means that controls light emission of the light source, and a light amount that detects the light emission amount of the light source. detection means, and the light emission control means controls the copying energy by stopping the light emission when the sum of the light emission amounts of the light sources detected by the light amount detection means reaches a predetermined value. Thermal copying device. (2) A transparent member for press-bonding a copy original and a material to be copied on a holding member, and a temperature detection means for detecting the temperature of the transparent member, and a light emission control means for controlling the temperature of the transparent member according to the temperature of the transparent member. A thermal copying apparatus according to claim 1, characterized in that the amount of copying energy is changed.