JPH031154B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a recording device using a liquid crystal optical shutter, and more particularly to a liquid crystal printer that uses a normally-off type liquid crystal optical shutter to control a light source on and off.

[Prior art]

A recording apparatus using a liquid crystal optical shutter is an apparatus that performs optical writing on a recording medium by driving the liquid crystal optical shutter to open and close using a control circuit to block or transmit light from a light source. Usually, a fluorescent lamp is used as a light source, and the optimal temperature at which the fluorescent lamp outputs the most efficient amount of light is 40°C. For this reason, in conventional liquid crystal printers, the temperature of the tube wall of the fluorescent lamp is maintained at 40° C. by attaching a surface heating heater to the tube wall of the fluorescent lamp and controlling the temperature of this heater.

[Problems with conventional technology]

In conventional LCD printers as mentioned above,
The heater installed on the pipe wall is about 20 to 30W,
Once the temperature reaches 40℃, it is sufficient to keep the temperature warm, but since a recording device is used, it takes time to raise the temperature to 40℃ from the time the main power is turned on, and it usually takes 5 to 10 minutes. It takes.

If the capacity of the heater is increased, the temperature rise time can be shortened, but there is a limit to the power consumption of the entire recording apparatus. It is also conceivable to keep only the heater in the on state even after the main power supply of the recording apparatus is turned off, but this is not preferable in terms of energy conservation.
Therefore, the conventional recording apparatus has the disadvantage that it takes time to start the recording operation.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the conventional printer, it is an object of the present invention to provide a liquid crystal printer that can shorten the warm-up time of a light source and efficiently drive a recording device.

[Summary of the Invention] In order to achieve the above object, the present invention provides a liquid crystal printer that selectively transmits light from a light source by opening and closing a liquid crystal light shutter to perform optical writing on a photoreceptor. It is characterized in that the light source is turned on while the light source is in a closed state.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram of the recording apparatus. In the figure, the surface of a photoreceptor 1 is uniformly charged in advance by a charger 2. As shown in FIG. The liquid crystal optical shutter section 3 is driven by a recording control section 4 that receives recording information and controls timing and the like, performs electro-optical conversion of the information, and performs optical writing on the surface of the photoreceptor 1. The electrostatic latent image thus formed is developed with toner in a developing device 5 and becomes a visible image. Further, the transfer paper 6 is fed by a paper feed roll 7, and a standby roll 8
At the transfer device 9, the toner image is transferred onto the transfer paper 6 in synchronization such that the leading edge of the transfer paper 6 and the toner image coincide with each other. Transfer paper 6
is separated from the photoreceptor 1 in the separating section 10, thermally fixed in the fixing device 11 whose temperature is controlled to a constant temperature by the thermistor 11a and the fixing heater, and then carried out of the machine by the paper discharge roll 12. On the other hand, since toner that was not completely transferred by the transfer device 9 remains on the surface of the photoconductor 1, the residual toner is neutralized by the electricity remover 13, and then cleaned by the cleaning section 14, and the photoconductor is cleaned by the eraser 15. After the surface of the photoreceptor 1 is neutralized, a uniform charge is again applied to the surface of the photoreceptor 1 by the charger 2 in preparation for the next exposure.

The structure of the liquid crystal optical shutter section 3 used in such a recording process will be explained with reference to FIG.

As shown in the figure, the liquid crystal light shutter section 3 includes a light source 16, a light source heater 17, a liquid crystal light shutter 18,
It is mainly composed of a liquid crystal optical heater 19, an imaging lens 20, and control boards 21a and 21b. A fluorescent lamp is used as the light source 16, and a light source heater 17 is used.
A thermistor 22 for detecting the temperature of the light source heater 17 is attached to one end. The liquid crystal light shutter 19 is a guest-host type liquid crystal light shutter, and its structure, as shown in FIGS. 3 and 4, is made by sealing a liquid crystal mixture between two glass substrates 23 and 24. 23 are provided with signal electrodes 25 alternately, and the glass substrate 24 is provided with a common electrode 26. The microshutter 27 is formed of a transparent electrode made of indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), or the like, and has the necessary size and shape at the intersection of the signal electrode 25 and the common electrode 26 . At least one polarizing plate and the liquid crystal heater 1 are attached to the liquid crystal panel 28 configured as described above.
9, the liquid crystal optical shutter 18 is constructed. Further, a thermistor 29 for detecting the temperature of the liquid crystal light shutter 18 is also attached to the liquid crystal light shutter 18 .

For optical writing on the photoreceptor 1, driving signals are applied to the signal electrode 25 and the common electrode 26 from the control boards 21a and 21b to control the opening and closing of each microshutter 27 of the liquid crystal optical shutter 18, and the microshutter 27 in the open state is controlled to open and close. This is performed by irradiating the surface of the photoreceptor 1 with light from the light source 16 that has passed through the shutter 27 .

The light source 16 used in the recording apparatus having the above configuration and performing optical writing will be described below, and the operation of the present invention will be explained in detail.

The amount of light from the fluorescent lamp used as the light source 16 depends on the temperature of the tube wall. FIG. 5 is a characteristic diagram showing this property, where the light intensity reaches its maximum when the tube wall temperature is around 40°C, and the light intensity decreases whether it is higher or lower than 40°C.
Therefore, when performing optical writing, the temperature of the light source 16 is 40°C.
It is desirable that the temperature be around .degree. C., and furthermore, it is necessary to bring the light source 16 to this temperature quickly after the main power of the recording apparatus is turned on.

The present invention provides a so-called normally-off type guest-host type liquid crystal optical shutter 1 that is in a closed state when there is no signal.
8 is used, even if the light source 16 is turned on at the same time as the main power is turned on, the surface of the photoreceptor 1 is not irradiated with light, and the photoreceptor 1 is not subjected to optical fatigue.

The control timing of each device until optical writing is performed will be explained with reference to FIGS. 6 and 7.

FIG. 6 is a control block diagram showing a light source temperature control section 30 consisting of a thermistor 22, a light source heater 17, etc., a thermistor 29, and a liquid crystal heater 19.
Output (each ready signal) 30 between the liquid crystal temperature control section 31 composed of the like, and the fixing temperature control section 32 which is balanced by thermistor 11a, fixing heater 11b, etc.
When a, 31b, and 32c are all turned on, the output 33a of the AND gate 33 is turned on, and the printer control section 34 is turned on.
operation, and optical writing on the photoreceptor 1 becomes possible.

That is, as shown in the time chart of FIG. 7, the light source 16 and the light source heater 17 are turned on at the same time as the main power of the recording apparatus is turned on, and at time D when the temperature of the light source 16 reaches 40° C., the light source 16 and the light source heater 17 are turned on. 17 is turned off and a ready signal 30a is output, and thereafter the light source heater 17 is repeatedly turned on and off at appropriate times in order to maintain the light source 16 at 40°C. Also, at the same time as the main power is turned on, the liquid crystal heater 19 and the fixing heater 1 are turned on.
1b is also turned on, and the liquid crystal optical shutter 18 and fixing device 11 are turned on.
Ready signal 3 at points E and F when the temperature reaches the appropriate temperature.
1b and 32c to the AND gate 33, and thereafter, the liquid crystal heater 19 and fixing heater 11b are repeatedly turned on and off in order to maintain the liquid crystal optical shutter 18 and fixing device 11 at appropriate temperatures. Here, time C
indicates main power is turned on.

As described above, by turning on the light source 16 at the same time as the main power is turned on, the light source 16 generates heat by itself, so that the tube wall temperature of the fluorescent lamp rises to 40°C in about 1 minute, as shown by curve A in FIG. The time taken to raise the temperature by 4 minutes can be shortened compared to curve B when heating is performed only by the light source heater 17 as in the conventional case.
In the time chart in Figure 7, time D is equal to time E and F.
Although it is shown earlier, this may not necessarily be the case depending on the installation condition of each device, room temperature, etc. Normally, the time required to warm up the light source 16 to an appropriate temperature is the longest, and by shortening this time according to the present invention, the time from turning on the main power to starting optical writing on the photoreceptor 1 (printing start time) can be shortened. .

Further, since the embodiment of the present invention uses a guest-host type liquid crystal light shutter, the photoreceptor 1 will not be fatigued and damaged by long-term light irradiation as described above.

The embodiments of the present invention are not limited to the above, and the liquid crystal light shutter is not limited to the guest-host type, but any normally-off type liquid crystal light shutter can be used in the present invention.

[Invention effect]

As described in detail above, according to the present invention, by turning on the light source at the same time as the main power is turned on using a normally-off type liquid crystal light shutter, the warm-up time of the light source can be shortened, and the recording device can be efficiently operated. Can be driven well. Also,
There is no need to use a large capacity heater for the light source, and there is no need to keep the light source heater on all the time.
It is also effective as an energy saving measure.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the liquid crystal light shutter section of the liquid crystal printer of the present invention, FIG. 2 is a block diagram of the recording device, and FIG.
Figure 4 is a configuration diagram of the liquid crystal panel, Figure 4 is a configuration diagram of the liquid crystal light shutter, Figure 5 is a light quantity characteristic diagram, Figure 6 is a circuit block diagram, Figure 7 is a time chart diagram, and Figure 8 is a diagram of the circuit block diagram.
The figure is a tube wall temperature characteristic diagram. 1...Photoreceptor, 3...Liquid crystal light shutter section, 11
... Fixing device, 11a, 22, 29 ... Thermistor, 11b ... Fixing heater, 16 ... Light source, 1
7... Heater for light source, 18... Liquid crystal light shutter,
19...Liquid crystal heater, 27...Micro shutter, 28...Liquid crystal panel, 30...Light source temperature control section, 31...Liquid crystal temperature control section, 32...Fixing temperature control section, 30a to 30c...Ready signal, 33
...AND gate, 34...Printer control unit.

Claims (1)

[Claims] 1. In a liquid crystal printer in which light from a fluorescent light source is selectively transmitted through opening and closing of a liquid crystal light shutter and optical writing is performed on a photoconductor, when the main power of the device is turned on, the liquid crystal light shutter is closed and the fluorescent light source is turned on. A liquid crystal printer characterized by: