JPH0827496B2 - Thermal copying machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive copying apparatus in which a copy original and a material to be copied are brought into close contact with each other and heat-sensitive copying is performed by irradiation of light from an exposure light source.

2. Description of the Related Art In recent years, an image forming apparatus using light rays as a thermal copying apparatus has been widely used in an electronic flash discharge tube type plate making machine, an OHP original making machine, and the like.

Form a temperature difference pattern by light irradiation of the exposure light source,
In a thermal copying apparatus for performing thermal copying, as a method of forming a temperature difference pattern, a method of forming a temperature difference pattern by a difference in light absorption between an image portion and a non-image portion of a copy original, or a method of selectively selecting light is used. There is a method of using a mask sheet having a transparent means.

Further, a discharge lamp equipped with a trigger electrode is used as an exposure light source of a thermal copying apparatus, a predetermined voltage is supplied between the anode and the cathode of the discharge lamp, and a trigger pulse is applied to the trigger electrode of the discharge lamp to turn on the discharge lamp. The discharge lamp lighting device for lighting has various specifications and forms ranging from a small one using one discharge lamp for business card copying to one using several discharge lamps for plain paper copying. Xenon flash lamps are mainly used as discharge lamps. The reason for using a plurality of discharge lamps as described above is that a large area copy can be made at one time. Next, you can speed up copying. And the transfer efficiency can be improved. It is easy to suppress the heat generation of the discharge lamp, and a copying machine using a plurality of discharge lamps is often used.

An example of the above-described conventional thermal copying apparatus will be described below with reference to the drawings.

FIG. 4 is a block diagram of a conventional discharge lamp lighting device of a thermal copying machine. In FIG. 4, 11 and 12 are xenon flash lamps.
The negative 11b of 11 and the anode 12a of the xenon flash lamp 12 are connected to form a series circuit. Further, the anode 11a of the xenon flash lamp 11 is the positive output terminal 13a of the power supply device 13.
In addition, the cathode 12b of the xenon flash lamp 12 is the power supply 1
3 is connected to the negative output terminal 13b. On the other hand, the trigger electrodes 11c and 12c of the xenon flash lamps 11 and 12 are connected to the trigger output 14a of the trigger device 14. Trigger device 14
The trigger output control input 14c is connected to the control output 15a of the trigger output controller 15. The cathode 12b of the xenon flash lamp 12 and the reference potential input terminal 14b of the trigger device 14
Also, the reference potential input terminal 15b of the trigger output control device 15 is connected and has the same potential.

The operation of the discharge lamp lighting device of the heat-sensitive copying apparatus configured as described above will be described below.

Both ends 11 of the series circuit of xenon flash lamps 11 and 12
When a predetermined voltage is supplied from the positive output terminal 13a and the negative output terminal 13b of the power supply device 13 to a and 12b, the trigger output control device
When the trigger output signal is output from the control output 15a of 15, the trigger device 14 outputs the trigger pulse from the trigger output 14a,
A high voltage is instantaneously applied to the trigger electrodes 11c and 12c, and a dielectric breakdown occurs in the tubes of the xenon flash lamps 11 and 12, and the xenon flash lamps 11 and 12 light up. At this time, since the xenon flash lamps 11 and 12 are connected in series, they are lit at the same time (for example, Japanese Patent Application No.
-54521).

Further, FIG. 5 shows an example of a thermal copying apparatus.
In FIG. 5, reference numeral 30 is a reflecting mirror, and 40 is a glass plate that faces the drum 50 and holds the copy original 60 and the recording paper 70 in close contact with each other, and the surface of the copy original 60 on the recording paper 70 side is heated. Meltable ink is applied. The xenon flash lamps 10 and 20 are used as exposure light sources. The xenon flash lamps 10 and 20 are the xenon flash lamps 11 and 12 shown in FIG. 4, and the xenon flash lamps 10 and 20 are used to turn on the xenon flash lamps 10 and 20. It is assumed that the discharge lamp lighting device of the conventional thermosensitive copying apparatus shown in FIG. 4 is used.

The operation of the heat-sensitive copying apparatus configured as described above will be described below.

The copy original 60 and the recording paper 70 are in close contact with each other between the glass plate 40 and the drum 50, and the xenon flash lamp 10, 20
When the light is emitted, the light emitted from the xenon flash lamps 10, 20 is reflected directly or by the reflecting mirror 30,
The light passes through the glass plate 40 and is irradiated onto the copy original 60. This time,
After light-heat conversion in the portion recorded as the image portion, the heat-meltable ink applied to the surface of the copy original 60 on the recording paper 70 side is melted and transferred to the recording paper 70 (for example, Japanese Patent Application No.
60-281351 gazette).

Problems to be Solved by the Invention However, since the xenon flash lamps 11 and 12 are turned on at the same time in the thermal copying apparatus having the above-described structure, a sound accompanying the light emission, that is, a light emission sound is also emitted at the same time. There is a problem that the volume of the generated sound becomes large.

In the thermal copying machine of FIG. 5, the illuminance distribution in the effective transfer area of the copy document 60 is as shown in FIG. However, this is the case where the light amounts of the xenon flash lamps 10 and 20 are the same. In FIG. 6, the horizontal axis is the position and the vertical axis is the illuminance, Ea is a graph of the illuminance distribution by the xenon flash lamp 10, and Eb is the xenon flash lamp 20.
Is a graph of the illuminance distribution by Ec, and Ec shows the illuminance of the combination of Ea and Eb. As you can see from the graph of Ec, the illuminance at the center of the effective transfer area becomes large. When the xenon flash lamps 10 and 20 emit light at the same time in this state, the temperature of the heat-meltable ink in the central portion of the effective transfer area of the copy document 60 becomes as shown in FIG. In FIG. 7, the horizontal axis represents time and the vertical axis represents temperature. Ta and Tb are graphs of temperature changes by the xenon flash lamps 10 and 20, respectively, and Tc shows temperature changes in the synthesis of Ta and Tb.
As can be seen from the graph of Tc, the maximum value T2 is about twice the maximum value T1 of Ta or Tb. Therefore, copy manuscript 60
There is a problem that the temperature of the heat-fusible ink rises significantly in the central portion of the effective transfer area, and the transfer density in the central portion of the effective transfer area also increases accordingly.

In view of the above problems, the present invention reduces the volume of light emission sound when lighting a plurality of discharge lamps, and compensates the transfer density of the central portion of the effective transfer area to obtain an image of uniform density at all times. The present invention provides a heat-sensitive copying apparatus for the purpose.

Means for Solving the Problems In order to solve the above problems, the thermal copying apparatus of the present invention may apply a trigger pulse to the trigger electrode by shifting each one or several discharge lamps by a predetermined time. A discharge lamp lighting device having a trigger output control device and a trigger device is provided.

Effect The present invention has the above-described configuration, and the light emission timing is shifted for every one or several discharge lamps, so that the timing of the light emission sound is also shifted, and the volume of the light emission sound can be reduced.

Also, by shifting the emission timing of each discharge lamp,
Since the temperature rise of the heat-melting ink of the copy original due to each discharge lamp deviates with time, the temperature rise of the central portion of the effective transfer area of the copy original is suppressed and the transfer density of the central portion of the effective transfer area is compensated, It is possible to always obtain an image of uniform density.

Embodiment A thermal copying machine according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a discharge lamp lighting device of a thermal copying machine according to a first embodiment of the present invention. First
In the figure, 1 and 2 are xenon flash lamps, and the anode 1a and cathode 1b of the xenon flash lamp 1 are connected to the positive output terminal 3a and the negative output terminal 3b of the power supply device 3, respectively, and the anode 2a and the cathode 2b of the xenon flash lamp 2 are connected. Are connected to the positive output terminal 4a and the negative output terminal 4b of the power supply device 4, respectively. The trigger electrode 1c of the xenon flash lamp 1 is connected to the trigger output 5a of the trigger device 5, and the trigger electrode 2c of the xenon flash lamp 2 is connected to the trigger output 6a of the trigger device 6. The output control input 5c of the trigger device 5 is connected to the control output 7a of the trigger output control device 7, and the trigger output control input 6c of the trigger device 6 is connected to the control output 7b of the trigger output control device 7. Further, the cathodes 1b and 2b of the xenon flash lamps 1 and 2, the reference potential input terminals 5b and 6b of the trigger devices 5 and 6 and the reference potential input terminal 7c of the trigger output control device 7 are connected to each other and have the same potential.

The operation of the discharge lamp lighting device of the thermal copying machine configured as described above will be described below with reference to FIG.

Xenon flash lamps 1, 2 anodes 1a, 2a and cathodes 1b, 2
When a predetermined voltage is supplied from the positive output terminals 3a, 4a and the negative output terminals 3b, 4b of the power supply devices 3, 4 between b, the trigger output control device 7 first outputs the trigger output signal from the control output 7a. Upon output, the trigger device 5 is the trigger electrode of the discharge lamp 1.
A xenon flash lamp 1 lights up by applying a trigger pulse to 1c. Xenon flash lamp 1 lights up for 1 mS
After a lapse of time, the trigger output control device 7 outputs a trigger output signal from the control output 7b. As a result, the trigger device 6 applies a trigger pulse to the trigger electrode 2c of the xenon flash lamp 2 to turn on the xenon flash lamp 2. Therefore, since the xenon flash lamps 1 and 2 do not emit light at the same time, the emission sound is reduced.

Next, the discharge lamp lighting device of the heat-sensitive copying apparatus according to the first embodiment of the present invention is used as a lighting device for the xenon flash lamps 10 and 20 of the heat-sensitive copying apparatus shown in FIG. Think to use. The xenon flash lamps 10 and 20 correspond to the xenon flash lamps 1 and 2 in the first embodiment of the invention, respectively.

The operation of the heat-sensitive copying apparatus configured as described above will be described below with reference to FIGS. 2 and 5.

First, when the xenon flash lamp 10 emits light, the temperature of the heat-meltable ink changes in the central portion of the effective transfer area of the copy document 60 as indicated by Ta in FIG. Next, when the xenon flash lamp 20 emits light, it shows a temperature change like Tb. However, the graphs of Ta and Tb show the temperature changes when the xenon flash lamps 10 and 20 each independently emit light. Therefore, the temperature change of the hot-melt ink is Ta and Tb at the center of the effective transfer area of the actual copy document 60.
Will be a combination of. In FIG. 2, Tc is a composite of Ta and Tb. Since the maximum values of Ta and Tb appear at different times, the maximum value T3 of Tc is smaller than the value when the xenon flash lamps 10 and 20 are simultaneously turned on.
Therefore, the temperature rise of the heat-melting ink in the central portion of the effective transfer area of the copy document 60 is suppressed, and the transfer density can be compensated in the central portion of the effective transfer area.

FIG. 3 is a block diagram of the discharge lamp lighting device of the thermal copying apparatus according to the second embodiment of the present invention. Third
In the figure, trigger transformers 501 and 601 are shown as trigger devices 5 and 6.
And a circuit including a single-shot pulse generator 701 and a delay circuit 702 is used as a trigger output control circuit.

The operation of the discharge lamp lighting device of the thermal copying apparatus configured as described above will be described below with reference to FIG.

The positive and negative output terminals 3a and 4a and the negative output terminals 3b and 4 of the power supply devices 3 and 4 are respectively provided between the positive and negative electrodes 1a and 2a and the negative electrodes 1b and 2b of the thermal copying machine.
When a single pulse is output from the single pulse generator 701 while a predetermined voltage is supplied from b, this pulse is immediately applied to the input side coil 502 of the trigger transformer 501. Since the coil 503 on the output side of the trigger transformer 501 is set to have a larger number of turns than the input side coil 502,
A high voltage is induced in the output side coil 503, and this voltage is applied as a trigger pulse to the trigger electrode 1c of the xenon flash lamp 1 to turn on the xenon flash lamp 1. The pulse output from the single pulse generator 701 is delayed by 1 mS in the delay circuit 702, and the trigger transformer 601
The high voltage induced on the input side coil 602 and induced on the output side coil 603 is applied to the trigger electrode 2c, and the xenon flash lamp 2 is turned on.

Therefore, the xenon flash lamp 2 emits light after 1 mS has elapsed since the xenon flash lamp 1 emits light.
Luminous sound is reduced.

Further, the discharge lamp lighting device of the heat-sensitive copying apparatus according to the second embodiment of the present invention is used as the lighting device of the xenon flash lamps 10 and 20 of the heat-sensitive copying apparatus shown in FIG. Think about it. The xenon flash lamps 10 and 20 correspond to the xenon flash lamps 1 and 2 in the second embodiment of the present invention, respectively.

Regarding the thermal copying machine configured as described above
The operation will be described with reference to FIGS.

The temperature change of the heat-meltable ink in the central portion of the effective transfer area of the copy original 60 of the thermal copying apparatus of FIG. 5 is as shown in the graph of FIG. 2 as in the case of the first embodiment. Therefore, as can be seen from the graph Tc of the temperature change caused by the xenon flash lamps 10 and 20, the temperature rise of the heat-meltable ink in the central portion of the effective transfer area of the copy document 60 is suppressed, so that the central portion of the effective transfer area is suppressed. The transfer density can be compensated.

Although the xenon flash lamp was used as the discharge lamp in the discharge lamp lighting device of the thermal copying apparatus of FIGS. 1 and 2, it is possible to use a discharge lamp with a trigger terminal other than the xenon flash lamp. . Further, although the number of the xenon flash lamps connected between the positive output terminal and the negative output terminal of each power supply device is one, it is possible to use two or more. Further, although two xenon flash lamps are arranged in parallel, three or more xenon flash lamps are provided, and accordingly a power supply device, a trigger device and a delay circuit may be added. Also, the negative output terminal of the power supply and the cathode of the xenon flash lamp,
The reference potential input terminal of the trigger device, one end of the input and output coils of the trigger transformer, and the reference potential input terminal of the trigger output control device are connected to each other and have the same potential, but if necessary due to the circuit configuration, etc. It does not matter if you divide it. Also, after the xenon flash lamp 1 lights up
After 1 mS has passed, the xenon flash lamp 2 is supposed to be turned on. However, the delay time may be changed depending on the heat capacity of the heat-meltable ink and the surrounding environment. A suitable time is 100 mS rather than 100 μS. is there.

Although the glass plate is used as the member for bringing the copy original and the material to be copied into close contact with each other in the heat-sensitive copying apparatus of the first and second embodiments, a transparent resin member may be used. Although the material to be copied is a recording sheet, other materials to be copied may be used. Further, although the drum for holding the recording sheet has a cylindrical shape, it may have a flat surface. Although the copy original is a sheet that transmits light according to the pattern, a general original is used as the copy original and a heat-sensitive color-developing transparent sheet is used as the material to be copied to heat the colored portions of the general original to generate heat. May be colored, or a transparent original and a thermosensitive coloring sheet may be used.

EFFECTS OF THE INVENTION As described above, according to the present invention, by providing a discharge lamp lighting device that emits light at different timings for one or several discharge lamps, the timing of the emitted sound is shifted and the volume of the emitted sound is reduced. can do. Further, it is possible to compensate the transfer density of the central portion of the effective transfer area.

[Brief description of drawings]

FIG. 1 is a block diagram of a discharge lamp lighting device of a thermal copying apparatus according to the first embodiment of the present invention, and FIG. 2 is a discharge lighting lamp of a thermal copying apparatus according to the first and second embodiments of the present invention. Of the thermal copying machine using the apparatus, the state diagram showing the temperature change of the hot-melt ink in the central portion of the effective transfer area of the copy original, and FIG. 3 is the discharge light point of the thermal copying machine in the second embodiment of the present invention. 4 is a block diagram of a discharge lamp lighting device of a conventional thermal copying apparatus, FIG. 5 is a front view of the thermal copying apparatus, and FIG. 6 is a copy original of the thermal copying apparatus of FIG. FIG. 7 is a state diagram showing the illuminance distribution of the light radiated to the effective transfer area, and FIG. 7 is the heat of the central portion of the effective transfer area of the copy original of the thermal copying apparatus using the discharge lamp lighting device of the conventional thermal copying apparatus. It is a state diagram showing a temperature change of the fusible ink. 1,2 …… Xenon flash lamp, 3,4 …… Power supply,
5,6 …… Trigger device, 501,601 …… Trigger transformer, 7…
… Trigger output controller, 701 …… Single pulse generator, 7
02 ... delay circuit.

Claims (1)

[Claims] 1. A transparent member, a facing member facing the transparent member, a copy original and a material to be copied, which are in close contact between the transparent member and the facing member, are irradiated with light to perform copying. ,
A plurality of discharge lamps placed in the direction opposite to the facing member when viewed from the transparent member, and light from the plurality of discharge lamps in the vicinity of the plurality of discharge lamps are collected in the direction of the transparent member. A heat-sensitive copying apparatus, comprising: a reflecting material; and a discharge lamp lighting device for emitting light at a different timing for each of the plurality of discharge lamps or several lamps.