JPH0887180A - Printing device - Google Patents

Abstract

PURPOSE: To shorten the time for controlling developer concentration and to uniformize concentration in a short time in a printing device. CONSTITUTION: This printing device 40 using the developer obtained by liquefying liquid toner by a solvent and developing an image by sticking toner to a latent image formed on a printing medium is provided with a concentration measuring means 42 measuring the toner concentration of the developer, a toner liquid supplying means 43 supplying liquid toner, a solvent supplying means 44 supplying the solvent, and a control means 41 supplying the liquid toner or the solvent by driving the supplying means 43 or 44 based on the measured result by the measuring means 42. By setting the toner concentration at the time of turning on a power source as reference, the toner concentration being the reference is controlled to be maintained until the power source is turned off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus using a liquid developing electrophotographic system, and more particularly to shortening the concentration control time of the developing solution for liquid development and uniformizing the concentration in a short time. The present invention relates to a printing device that enables the printing.

Conventionally, in plate making in commercial offset printing, a developed silver salt film is used as a PS plate (Pre-sensitized Plate).
It was done by closely baking to
A so-called direct plate making apparatus has been proposed in which a plate material using a photosensitive material having high sensitivity to a laser beam is exposed by a laser beam and developed.

In such an apparatus, since the above-mentioned development is carried out by using a developing solution in which liquid toner is dissolved in isopa (solvent), the concentration of the above-mentioned liquid toner is always maintained at a constant value within a predetermined range. Is controlled.

Therefore, until the concentration of the liquid toner reaches a constant value within a predetermined range, the direct plate-making device is
Since it is not possible to develop the exposed plate material and the development process is delayed during that period, it is desired to shorten the time for controlling the density and shorten the time required for uniformizing the density. There is.

[0005]

2. Description of the Related Art An automatic plate making apparatus has been proposed in Japanese Utility Model Application Laid-Open No. 4-112266 by the present applicant, the outline of which will be described below.

FIG. 8 is a diagram illustrating an example of an automatic plate making apparatus. In the figure, 1 is a plate supply section, 2 is an exposure section, 3 is a development section, 4
Is a drying part, 5 is a fixing part, 6 is a cooling part, 7 is an elution part, 8 is a gum part, and 9 is a drying part.

The plate supply section 1 is a storage case for stacking and storing a plurality of plate materials (hereinafter referred to as works) 11. The work 11 in the storage case 10 is a pickup device 1.
It is supplied onto the conveyance line by 2 and is conveyed to the exposure unit 2.

The exposure unit 2 is composed of a charger 13, a scanning optical system such as a polygon mirror 15, a table 14 and a laser irradiation device (not shown). The work 11 is a plate material in which a surface of an aluminum plate is coated with a photosensitive material having high sensitivity to a laser beam.

The developing section 3 is provided with a developer 1 on the surface of the work 11.
7, a developer tank 18 for supplying the developer 7, a liquid recovery tray 21 for recovering the developer 17, an electrode plate 19 and a work support bed 20.
And the ground terminal 16 and the like.

With this structure, the work 11 in the storage case 10 is picked up by the pickup device 12 as described above.
Is supplied to the conveyor line, is sent to the exposure unit 2, and is set on the table 14.

Then, a host computer (not shown)
Based on the exposure record information sent from (hereinafter referred to as a host), the exposure mechanism including the laser irradiation device, the charger 13 and the polygon mirror 15 is driven, and
The table 14 is moved at a predetermined speed corresponding to the resolution (for example, 454 DPI (dots / inch), 681 DPI, 909 DPI), and the laser beam from the laser irradiation device is irradiated as scanning light by the polygon mirror 15 to rotate the workpiece. An electrostatic latent image is formed on the surface of 11.

The work 11 on which the electrostatic latent image is formed is conveyed to the developing section 3, and a predetermined bias voltage is applied from the electrode plate 19 to the work 11 whose back surface is in contact with the ground terminal 16, so that the work support bed 20 is provided. A developing solution discharge port (not shown) provided on the electrode plate 19 from the developing solution tank 18 while moving above.
The exposed surface is uniformly wetted by the developing solution 17 supplied via the toner, and toner is attached to the electrostatic latent image of the work 11 to be developed.

The developed work 11 is dried in the drying unit 4 and then heated in the fixing unit 5 so that the toner is fixed, and the cooling unit 6 is used.
After that, after passing through the elution portion 7 that etches the portion to which the toner is not attached, the gum portion 8 is gummed for protecting the plate surface, and dried in the drying portion 9 to complete the plate making process.

FIG. 9 is a diagram for explaining the structure of the developing section.
As described above, the work 11 conveyed from the exposure unit 2 is conveyed by the material supply roller 30 and the work support bed 20.
And between the electrode plates 19.

When the control unit (not shown) is notified by the exposure unit 2 that the work 11 is conveyed, the circulation pump 23 is driven to deliver the developer in the developer tank 22 to the developer tank 18. The developer 17 that has crossed over the weir 32 provided to uniformly wet the work 11 in the tank 18 as shown by the arrow A from the developer discharge port 33 to the electrode plate 19 and the work support bed 20. Is supplied to.

Therefore, the work 11 carried in by the material supply roller 30 is developed by the developer 17 with toner attached to the latent image portion. The developing solution is removed from the developed work 11 by the squeeze roller 31, and the developing solution dropped on the solution collecting tray 21 is collected in the developing solution tank 22.

Further, since the work 11 is inserted between the electrode plate 19 and the work support bed 20, the developer 17 flowing in the direction of the material supply roller 30 is also removed by the material supply roller 30 and the liquid recovery tray. It is dropped to 21 and collected in the developer tank 22.

The control unit is the upper surface sensor 3 of the developer tank 22.
4 and the output of the lower surface sensor 35, the capacity of the developing solution is below the position of the upper surface sensor 34 and above the position of the lower surface sensor 35, and the toner density detected by the density sensor 36 is deviated from the reference value. Control so that it falls within the range of values.

Therefore, the toner pump 25 is driven to send the liquid toner from the liquid toner tank 24 to the developer tank 22, or the solvent pump 27 is driven to send the isopa from the solvent tank 26 to the developer tank 22. .

Further, the control unit drives the cleaning pump 29 in accordance with an instruction from the host to supply the isopa from the solvent tank 28 to the material supply roller 30 and the squeezing roller 31 to clean the respective rollers.

This is because, after a series of development processing is completed, the material supply roller 30 to which the developing solution 17 is attached and the squeeze roller 31.
If left as it is, it will be contaminated with toner and the work 1
This is because the development of No. 1 is adversely affected.

[0022]

Conventionally, the reference value of the toner density is fixed, so the toner density is always controlled so as to be within the fixed value of the fixed reference value (for example, ± 2.5%). Was there.

That is, for example, the toner density is 70% to 13%.
Within the range of 0%, there is no problem in developing the work 11, and it suffices that the toner concentration falls within this effective range.
For example, since the reference value of the toner concentration is 100%, if the toner concentration is 80%, the toner pump 25 is driven and the liquid toner is replenished until the toner concentration becomes 100 ± 2.5%. , 110% of the toner concentration, the solvent pump 27 was driven to supplement the isopa until the toner concentration became 100 ± 2.5%.

Further, since the replenishment amount of the liquid toner and the replenishment amount of the isopa are always constant, the toner concentration may become too thick when the liquid toner is replenished, or the toner concentration may become too thin when the isopa is replenished. It took time for the toner concentration in the developer tank 22 to fall within the fixed value of the fixed reference value.

Therefore, there is a problem that the time for controlling the toner density becomes long and the toner density is controlled unnecessarily, so that the printing efficiency is lowered. In view of these problems, the present invention aims to shorten the toner concentration control time, eliminate unnecessary toner concentration control, and shorten the time required to make the concentration uniform.

[0026]

FIG. 1 is a block diagram for explaining the principle of the present invention. 1) The printing device 40 develops a latent image formed on a print medium by adhering toner using a developing solution in which liquid toner is dissolved in a solvent.

The density measuring means 42 for measuring the toner density of the developer, the toner liquid replenishing means 43 for replenishing the liquid toner, the solvent replenishing means 44 for replenishing the solvent, and the density measuring means 42 are included. A control means 41 for driving the toner liquid replenishing means 43 or the solvent replenishing means 44 based on the measurement result to replenish the liquid toner or the solvent is provided, and the toner concentration at power-on is used as a reference until power-off. The control is performed so as to maintain the standard toner density.

2) The printing device 40 develops the latent image formed on the printing medium by attaching the toner to the latent image formed on the printing medium by using a developing solution obtained by dissolving the liquid toner in a solvent. The concentration measurement means 42 for measuring the toner concentration of the developer, the toner liquid replenishing means 43 for replenishing the liquid toner, the solvent replenishing means 44 for replenishing the solvent, and the measurement result of the concentration measuring means 42 On the basis of this, a control means 41 for driving the toner liquid replenishing means 43 or the solvent replenishing means 44 to replenish the liquid toner or solvent, and an instruction means 45 for instructing the toner concentration control method of the control means 41 are provided. , Whether the control means 41 should maintain the toner density when the power is turned on,
Alternatively, it is possible to instruct whether to maintain the designated toner density.

3) The printing device 40 reads the toner concentration of the developing solution in which the liquid toner is dissolved by the solvent based on the input reference value, and determines whether the deviation amount from the reference value is within the range of the specified value. When the input reference value is within the effective range of the toner density, the latent image formed on the print medium is developed by this developing solution.

A control means 41 for changing the input reference value based on the measurement result of the concentration measuring means 42 is provided, and the result of the concentration measurement based on the reference value input to the concentration measuring means 42 is If the deviation from the reference value is outside the specified range and the toner density is deviating in the dark direction, enter this deviating value in the dark direction and then measure the density. If the result of the density measurement shows that the deviation amount from the reference value is outside the specified value range and the toner density is deviated in the direction of lighter toner density, the reference value The process of measuring the density after repeating the input in the light direction by a predetermined value is repeated to search for a reference value at which the toner density measured based on the input reference value falls within the effective range of the toner density. .

4) The printing device 40 reads the toner concentration of the developing solution obtained by dissolving the liquid toner in the solvent based on the input reference value, and determines whether the deviation amount from the reference value is within the range of the specified value. When the input reference value is within the effective range of the toner density, the latent image formed on the print medium is developed by this developing solution.

A control means 41 for changing the input reference value based on the measurement result of the density measurement means 42 is provided, and the reference value input to the density measurement means 42 is set to the maximum of the effective range of the toner density. The value A and the minimum value B are set, and the reference value to be input subsequently is (A + B) / 2 = C,
The reference value to be input subsequently is (C + A) / 2 = D and (C +
B) / 2 = E, and the reference value to be input subsequently is (A + D)
/ 2 = F and (D + C) / 2 = G and (C + E) / 2 =
Toner measured based on the input reference value is repeated by always obtaining an intermediate value between the upper and lower reference values input in advance such that H and (E + B) / 2 = J, and then performing density measurement. A reference value whose density is within the effective range of the toner density is searched for.

5) The printing device 40 reads the toner concentration of the developing solution in which the liquid toner is dissolved by the solvent based on the input reference value, and determines whether the deviation amount from the reference value is within the specified value range. When the input reference value is within the effective range of the toner density, the latent image formed on the print medium is developed by this developing solution.

Then, the control means 41 for changing the input reference value based on the measurement result of the concentration measuring means 42.
And an instructing unit 45 for instructing the concentration measuring unit 42 how to change the reference value input by the control unit 41. The reference value is sequentially shifted by a predetermined value and input, or first. It is possible to specify whether to obtain the intermediate value between the upper and lower two reference values that have been input.

6) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22 and pours the developing solution into the printing medium through the developing solution tank 18 by the developing solution circulating means 46. After that, the toner is attached to the latent image formed on the print medium by being refluxed in the developer tank 22, and the latent image is developed.

A concentration measuring means 42 for measuring the toner concentration of the developing solution and a control means 41 for controlling the developing solution circulating means 46 are provided, and the developing solution is turned on when the power is turned on or before the toner concentration is measured. After driving the circulation means 46 for a predetermined time, the toner concentration in the developer tank 22 is measured.

7) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22, and after the developing solution is circulated through the developing solution tank 18 by the developing solution circulating means 46, the developing solution is poured onto the printing medium. By recirculating to the developer tank 22, toner is attached to the latent image formed on the print medium to develop the latent image.

The density measuring means 42 for measuring the toner density of the developer, the toner liquid replenishing means 43 for replenishing the liquid toner, the solvent replenishing means 44 for replenishing the solvent, and the density measuring means 42 Based on the measurement result, the toner solution replenishing means 43 or the solvent replenishing means 44 is driven to replenish the developer tank 22 with a predetermined amount of the liquid toner or solvent, and at the same time, a control means for controlling the developer circulating means 46. 41 is provided, and when the toner solution replenishing means 43 or the solvent replenishing means 44 is driven, the developer circulating means 46 is driven for a predetermined time, and then the developer tank 2 is provided.
Measure the toner density of 2.

8) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22, and after pouring the developing solution into the printing medium through the developing solution tank 18 by the developing solution circulating means 46. By recirculating to the developer tank 22, toner is attached to the latent image formed on the print medium to develop the latent image.

The density measuring means 42 for measuring the toner density of the developing solution, the toner liquid replenishing means 43 for replenishing the liquid toner, the solvent replenishing means 44 for replenishing the solvent, and the density measuring means 42 are included. Based on the measurement result, the toner solution replenishing means 43 or the solvent replenishing means 44 is driven to replenish the developer tank 22 with the liquid toner or the solvent, and the controlling means 41 for controlling the developing solution circulating means 46 is provided. The amount of the liquid replenished by the toner liquid replenishing unit 43 at one time is smaller than the amount of the liquid replenished by the solvent replenishing unit 44 at a time, so that the developer circulating unit 46 before the toner concentration measurement is performed. The driving time is the same.

9) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22 and, after pouring the developing solution into the printing medium through the developing solution tank 18 by the developing solution circulating means 46. By recirculating to the developer tank 22, toner is attached to the latent image formed on the print medium to develop the latent image.

The concentration measuring means 42 for measuring the toner concentration of the developing solution, the toner liquid replenishing means 43 for replenishing the liquid toner, the solvent replenishing means 44 for replenishing the solvent, and the concentration measuring means 42. Referring to a table 47 for instructing a preset replenishment amount of the liquid toner and the solvent from the measurement result, the toner liquid replenishing means 43 or the solvent replenishing means 44 is driven to put the liquid toner or the solvent in the developer tank 22. And the developer circulating means 46
And a control means 41 for controlling the.

The larger the amount of deviation of the toner concentration from the reference value to be maintained, the larger the amount of the liquid toner or solvent to be replenished. 10) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22, pours the developing solution into the printing medium through the developing solution tank 18 by the developing solution circulating means 46, and then develops the developing solution. By recirculating to the tank 22, toner is attached to the latent image formed on the print medium to develop the latent image.

The concentration measuring means 42 for measuring the toner concentration of the developing solution, the toner liquid replenishing means 43 for replenishing the liquid toner, the solvent replenishing means 44 for replenishing the solvent, and the concentration measuring means 42. The table 47 for instructing the preset replenishment amounts of liquid toner and solvent and the driving time of the developer circulating means 46 is referred from the measurement result, and the toner replenishing means 43 or the solvent replenishing means 44 is driven to The developer tank 22 is provided with control means 41 for replenishing the liquid toner or solvent and controlling the developer circulation means 46.

Then, the larger the deviation amount of the toner concentration from the reference value to be maintained, the longer the driving time of the developing solution circulating means 46. 11) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22, pours the developing solution into the printing medium through the developing solution tank 18 by the developing solution circulating means 46, and then the developing solution. By recirculating to the tank 22, toner is attached to the latent image formed on the print medium to develop the latent image.

The density measuring means 42 for measuring the toner density of the developer, the toner liquid replenishing means 43 for replenishing the liquid toner, the solvent replenishing means 44 for replenishing the solvent, and the density measuring means 42 are included. The table 47 for instructing the preset replenishment amounts of liquid toner and solvent and the driving time of the developer circulating means 46 is referred from the measurement result, and the toner replenishing means 43 or the solvent replenishing means 44 is driven to Control means 41 for replenishing the developer tank 22 with the liquid toner or solvent and controlling the developer circulation means 46, and instruction means 45 for instructing the control means 41 whether or not to refer to the table 47. Is provided.

When referring to this table 47, the larger the deviation amount of the toner concentration from the reference value to be maintained, the larger the liquid amount of the liquid toner or solvent to be replenished and the developing solution circulating means. When the time for driving 46 is extended and the table 47 is not referred to, the liquid toner or the solvent is replenished with a predetermined value, and the developing solution circulating means 46 is driven with a predetermined value.

12) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22, and after pouring the developing solution into the printing medium through the developing solution tank 18 by the developing solution circulating means 46. By recirculating to the developer tank 22, toner is attached to the latent image formed on the print medium to develop the latent image.

Then, the toner concentration of the developing solution in the developing solution tank 22 is read based on the inputted reference value, and the density measuring means is indicated by whether or not the deviation amount from the reference value is within the range of the specified value. 42, toner liquid replenishing means 43 for replenishing the liquid toner, and solvent replenishing means 44 for replenishing the solvent.
The toner replenishing means 43 or the solvent replenishing means 44 is driven based on the measurement result of the concentration measuring means 42 to replenish the developer toner tank 22 with the liquid toner or the solvent, and the developer circulating means 46 is operated. The control means 41 for controlling is provided, and when the toner density is low beyond the range of the specified value of the density measuring means 42, the toner liquid replenishing means 4 is provided.
3 and the developer circulating means 46 are driven to measure the toner concentration, and when the toner concentration is within the range of the specified value of the concentration measuring means 42, the toner solution replenishing means 43 and the developer circulating means 46. When the toner concentration is higher than the specified value range of the concentration measuring means 42, the solvent concentration is measured while driving the solvent replenishing means 44 and the developer circulating means 46. Is within the range of the specified value of the concentration measuring means 42, the solvent replenishing means 4
4 and the developer circulating means 46 are stopped.

13) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22, and after pouring the developing solution into the printing medium through the developing solution tank 18 by the developing solution circulating means 46. By recirculating to the developer tank 22, toner is attached to the latent image formed on the print medium to develop the latent image.

Then, the toner concentration of the developing solution in the developing solution tank 22 is read based on the input reference value, and the density measuring means is indicated by whether the deviation amount from the reference value is within the range of the specified value or not. 42, toner liquid replenishing means 43 for replenishing the liquid toner, and solvent replenishing means 44 for replenishing the solvent.
The toner replenishing means 43 or the solvent replenishing means 44 is driven based on the measurement result of the concentration measuring means 42 to replenish the developer toner tank 22 with the liquid toner or the solvent, and the developer circulating means 46 is operated. Control means 41 for controlling
Further, the control means 41 is provided with an instruction means 45 for instructing whether to measure the toner concentration after replenishing a certain amount of the liquid toner or solvent or to replenish the liquid toner or solvent while measuring the toner concentration. When shortening the replenishment time of liquid toner or solvent, the liquid toner or solvent is replenished while measuring the toner concentration, and when the replenishment amount of liquid toner or solvent is reduced, a certain amount of liquid toner or solvent is replenished. After that, the toner density is measured.

14) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22 provided with the solution amount detecting means 48 for detecting the amount of the developing solution, and the developing solution circulating means. The developer is poured into the print medium through the developer tank 18 by the reference numeral 46 and then is returned to the developer tank 22, so that toner is attached to the latent image formed on the print medium to develop the latent image.

Then, the toner concentration of the developing solution in the developing solution tank 22 is read based on the inputted reference value, and the density measuring means is indicated by whether the deviation amount from the reference value is within the range of the specified value or not. 42, toner liquid replenishing means 43 for replenishing the liquid toner, and solvent replenishing means 44 for replenishing the solvent.
Then, the toner liquid replenishing means 43 or the solvent replenishing means 44 is driven based on the measurement result of the concentration measuring means 42 and the detection result of the liquid amount detecting means 48 to replenish the developer toner tank 22 with the liquid toner or solvent. In addition, a control means 41 for controlling the developing solution circulating means 46 is provided, and when the amount of the developing solution in the developing solution tank 22 decreases below a predetermined value, the solvent is replenished until it reaches the predetermined value. After that, the toner concentration is measured and the required amount of liquid toner is replenished.

15) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22, and after the developing solution is circulated through the developing solution tank 18 by the developing solution circulating means 46, the developing solution is poured onto the printing medium. By recirculating to the developer tank 22, toner is attached to the latent image formed on the print medium to develop the latent image.

Then, the density measuring means 42 for measuring the toner density of the developing solution in the developing solution tank 22, and the control for instructing the start of the density measurement of the density measuring means 42 and controlling the developing solution circulating means 46. Means 41 and
At a predetermined time point, the developer is circulated for a predetermined time and then the density is measured.

16) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22, and after pouring the developing solution into the printing medium through the developing solution tank 18 by the developing solution circulating means 46. By recirculating to the developer tank 22, toner is attached to the latent image formed on the print medium to develop the latent image.

Then, the density measuring means 42 for measuring the toner density of the developing solution in the developing solution tank 22, the instruction to start the density measurement of the density measuring means 42, and the control for controlling the developing solution circulating means 46. Means 41 and instructing means 45 for instructing the control means 41 when to start the concentration measurement are provided. At the time when this instructing means 45 gives an instruction,
After circulating the developing solution for a predetermined time, the density is measured.

17) The printing device 40 stores the developing solution in which the liquid toner is dissolved in the solvent in the developing solution tank 22, and after pouring the developing solution into the printing medium through the developing solution tank 18 by the developing solution circulating means 46. By recirculating to the developer tank 22, toner is attached to the latent image formed on the print medium to develop the latent image. Then, a concentration measuring means 42 for measuring the toner concentration of the developing solution in the developing solution tank 22, and a control means 41 for instructing the start of the concentration measurement of the concentration measuring means 42 and controlling the developing solution circulating means 46. , This control means 4
1 is provided with an instruction means 45 for instructing a concentration measurement start time point, and a selection means 49 for causing the control means 41 to select whether to instruct the concentration measurement start time or to start the concentration measurement at a predetermined time point. This instruction means 45
At the point of time, the density of the developer is circulated for a predetermined time and then the density is measured, or at the time of predetermined, the density of the developer is circulated for a predetermined time and then the density is measured.

[0059]

With the above arrangement, the printing apparatus 40 according to the first aspect maintains the toner concentration measured when the power is turned on, so that the replenishment time of liquid toner or isopa can be shortened. .

That is, since the toner concentration when the power is turned off is within the effective range that does not hinder the development, it should be within the effective range when the power is turned on. If the toner concentration at this time is taken as a reference, the toner is immediately developed. It is possible to start.

Further, in the printing apparatus 40 according to the second aspect, when the toner density when the power is turned on is out of the effective range, the density can be controlled with reference to the toner density designated by the instructing means 45. I can.

If the toner concentration designated at this time is designated within the effective range close to the toner concentration measured when the power is turned on, the replenishment time of the liquid toner or isopa can be shortened.

Further, in the printing apparatus 40 according to the third aspect, the density measuring means 42 defines a range defined from the input reference value,
For example, because it is possible to measure ± 2.5% of the range, input a certain reference value for measurement, and if it is outside the specified range, repeat the operation of inputting a different reference value for measurement. , It is necessary to decide the reference value to enter.

Therefore, if the result of the first measurement indicates that there is a shift in the dark direction, for example, by shifting the reference value by a predetermined value, for example, 5%, inputting it, and repeating the operation of re-measurement, , The reference value can be searched promptly.

Further, in the printing apparatus 40 according to the fourth aspect, the maximum value of the effective range of the density, for example, 130% is inputted as a reference value, and when the result of the density measurement is deviated in the thin direction, the density is effective. If the lowest value in the range, for example 70%, is entered as the reference value and the result of the concentration measurement is shifted in the dark direction, enter the intermediate value of the two upper and lower reference values entered earlier, that is, enter 100% for measurement. Since the operation of doing is repeated, the reference value can be searched earlier than the printing apparatus 40 according to the third aspect.

Further, in the printing apparatus 40 described in claim 5, the method for determining the reference value can be specified by the method described in claim 3 or the method described in claim 4, so that the environmental conditions and the usage state of the printing apparatus 40. It is possible to select a prompt reference value determination method corresponding to.

Further, in the printer 40 according to the sixth aspect, since the toner concentration of the developer tank 22 is measured, the toner concentration of the developer supplied from the developer tank 18 to the print medium by the developer circulating means 46. However, this difference in concentration can be eliminated.

In the printer 40 according to the present invention, a certain amount of liquid toner or isopa is replenished to make the toner concentration in the developer tank 22 which is not uniform. It is possible to measure various concentrations.

Further, in the printing apparatus 40 according to the eighth aspect, it takes less time to replenish the liquid toner to increase the density than to replenish the isopa to decrease the density. By increasing the amount, the time until the concentration becomes uniform can be made the same.

Further, the printing apparatus 40 according to the ninth and tenth aspects, by referring to the table 47, promptly sets the reference value for maintaining the toner density in accordance with the deviation amount from the reference value. Can be matched.

Further, in the printing apparatus 40 according to the eleventh aspect, when the toner concentration deviates from the effective range beyond the reference of the table 47, liquid toner or isopa is replenished with a predetermined value and the developing solution is circulated. Can be done.

Further, in the printing apparatus 40 according to the twelfth aspect, since the toner concentration is measured while continuously replenishing the liquid toner or isopa, the replenishment amount of the liquid toner or isopa is required to be larger than the method of replenishing the constant amount. However, the toner density can reach the target value fastest.

Further, in the printing apparatus 40 according to the thirteenth aspect, even if the replenishment amount of the liquid toner or isopa is large, the toner concentration is quickly reached to the target value, or the replenishment of the liquid toner or isopa is taken even if it takes time. You can choose to save the amount. Therefore, by switching depending on the remaining amount of the replenisher and the time that can be spent for the replenishment, the processing corresponding to the usage state of the printing device 40 can be performed.

Further, in the printing device 40 according to the fourteenth aspect, when the liquid surface of the developer tank 22 is lower than a predetermined value, for example, the position of the lower surface sensor, priority is given to the liquid surface control only with ISOPA, and then the liquid toner is removed. Since the toner is replenished, the time required for the toner density to match the reference value can be minimized. This is because, as described above, it is faster to replenish the liquid toner to increase the concentration thereof than to reduce the concentration with Isopa.

Further, the printer 40 according to claim 15 does not always measure the toner density but rather executes it at a predetermined point in time, and the measurement is performed after an operation causing density fluctuation is performed. It is something that is done.

Further, the printing apparatus 40 according to the sixteenth aspect enables the toner density to be measured at the time when the instruction means 45 gives an instruction, and the toner density can be measured at any time.

Further, in the printing device 40 according to the seventeenth aspect, it is possible to prevent unnecessary measurement of the toner density by the selecting means 49.

[0078]

FIG. 2 is a block diagram of a circuit showing an embodiment of the present invention. The processor 50 operates by reading the program stored in the ROM 51, and communicates with the other plate supply unit 1, exposure unit 2, elution unit 7 and the like shown in FIG. 8 via the interface circuit 53.

When the toner density becomes low, the processor 50 controls the drive circuit 55 via the input / output port 54,
The toner pump 25 is driven to replenish the liquid toner to the developer tank 22 shown in FIG. 9, and when the toner concentration becomes high, the drive circuit 56 is controlled to drive the solvent pump 27 to drive the developer tank 22.
Replenish with isopa.

Then, when measuring the toner density,
When the developing solution is poured into the work 11 shown in FIG. 9, the drive circuit 57 is controlled to drive the circulation pump 23 to send the developing solution from the developing solution tank 22 to the developing solution tank 18 shown in FIG. Circulate the developing solution inside.

When the toner density is measured, the processor 50 inputs a reference value to the density measuring circuit 58 via the input / output port 54, and the toner density sent from the density sensor 36 is deviated from the reference value by a specified value. If the toner density deviates from the reference value by more than the specified value, the operation of changing the reference value and measuring again is repeated, and the measured value is changed from the input reference value. When the deviation amount is within the specified value, it is determined that the measurement of the toner density is completed.

FIG. 3 is a block diagram showing an example of the density measuring circuit. The processor 50 assumes that the toner concentration of the developer is a concentration range that does not hinder the development of the latent image on the print medium, that is, an effective concentration range of, for example, 130% to 70%, and the D / A conversion circuit 66. Enter a reference value that changes in 5% steps.

That is, hexadecimal FFF indicating 130%
From (the hexadecimal number is represented with $), $ EAA indicating 125%, $ D55 indicating 120%, $ BFF indicating 115%, $ AAA indicating 110%, and $ indicating 105%.
955, $ 800 showing 100%, $ 6A showing 95%
A, $ 555 showing 90%, $ 3FF showing 85%, 8
$ 2AA for 0%, $ 155 and 70% for 75%
Enter $ 000 indicating.

With respect to the above-mentioned reference value input to the D / A conversion circuit 66, the input digital value is converted into an analog value and amplified by the operational amplifier 70.
9 is sent.

The density sensor 36 is composed of, for example, a light emitting diode and a light receiving diode. The light emitted from the light emitting diode is attenuated in accordance with the toner concentration of the developing solution, is received by the light receiving diode, and corresponds to the received light amount. The voltage is amplified by the operational amplifier 68, enters the operational amplifier 69, is compared with the reference value, and the deviation amount from the reference value is sent to the A / D conversion circuit 67.

Since the A / D conversion circuit 67 outputs the deviation amount from the reference value in 256 steps, the input analog value is $.
It is sent to the processor 50 in the range of 00 to $ FF. That is, if it is $ 00, the toner density is + 2.5% from the standard value.
If it is $ FF, it means that the toner density deviates from the reference value by -2.5% or more. If it is $ 80, it means that there is no deviation from the reference value. Therefore, the toner density can be measured within the range of ± 2.5% from the reference value.

When the developer reaches the position, the upper surface sensor 34 notifies the processor 50 that the liquid level of the developer tank 22 has reached the upper limit via the amplifier circuit 59 and the input / output port 54.

Further, the lower surface sensor 35 notifies the processor 50 that the liquid level of the developer tank 22 has passed the lower limit via the amplifier circuit 60 and the input / output port 54 when the developer drops below that position.

From the operator panel 61, an instruction from the operator is input to the processor 50 via the input / output port 54 by a switch or the like operated by the operator. The switch 62 is designed so that an operator's instruction can be input to the processor 50 only when necessary.

The RAM 52 is a memory for storing the data required by the processor 50, and the table 47 stores the data required for the density control by the processor 50.
When the processor 50 is notified of the conveyance of the work 11 from the exposure unit 2 via the interface circuit 53, the processor 50 controls the drive circuit 63 via the input / output port 54 to drive the motor 65 to supply the feed roller 30 shown in FIG. And the aperture roller 31 is rotated.

Further, as described above, according to the instruction from the host, the drive circuit 64 is driven to drive the cleaning pump 29,
The material feeding roller 30 and the squeezing roller 31 are cleaned. 1) When the power is turned on, the processor 50 inputs the reference value to the density measuring circuit 58 and measures the toner density as described above. If the toner density is within the effective range, the power is supplied to this density. Toner pump 2 to maintain until cutting
5 or the solvent pump 27 is driven to replenish the developer tank 22 with liquid toner or isopa.

2) When the processor 50 is instructed by the operator panel 61 to maintain the toner concentration when the power is turned on, the processor 50 is instructed to perform the above operation and maintain the specified toner concentration. , Operator panel 6
It operates so as to maintain the toner density input from 1.

3) The processor 50 uses the concentration measuring circuit 58.
When the reference value is input to the D / A conversion circuit 66 of, for example, $ 800 (100%) is input and the A / D conversion circuit 67 is input.
Sends $ 00, $ 955 (105%) D /
When input to the A conversion circuit 66 and the A / D conversion circuit 67 still outputs $ 00, $ AAA (110%) is D / A.
Input to the conversion circuit 66, and the A / D conversion circuit 67 inputs $ 00.
When a hexadecimal number between 0 and $ FF is sent, this $ AA
A (110%) is used as a reference value.

On the contrary, the processor 50 costs $ 800 (10
0%) is input to the D / A conversion circuit 66 and the A / D conversion circuit 6
When 7 sends $ FF, $ 6AA (95%)
When the A / D conversion circuit 67 outputs $ FF to the A / D conversion circuit 66, $ 555 (90%) is input to the D / A conversion circuit 66 so that the A / D conversion circuit 67 When a hexadecimal number between $ 00 and $ FF is sent, this $ 555
(90%) is used as a reference value.

4 and 5 are flow charts for explaining an example of the reference value setting. The operations of FIG. 4 and FIG. 5 are to quickly determine the reference value by obtaining an intermediate value between the two reference values input previously and setting it as a new reference value.

4) The processor 50 uses the concentration measuring circuit 58.
When the reference value is input to the D / A conversion circuit 66 of No. 1, when the power is turned on, the reference value is input as A = $ FFF (130%) which is the highest value of the effective range of the toner density in step (1). , Check whether the concentration data is $ 00 in step (2).

When the A / D conversion circuit 67 sends out $ 00, the processor 50 has a density of 130% or more at the step (5) and is too dark, so isopace is replenished and the step
Return to processing of (1).

If the density data is not $ 00 in step (2) and the A / D conversion circuit 67 does not send out $ 00 in step (2), the processor 50 checks whether the density data is $ FF in step (3), and performs A / D conversion. When the circuit 67 sends out $ FF, the reference value is input to the D / A conversion circuit 66 as B = $ 000 which is the lowest value of the effective range of the toner density in step (6). If the circuit 67 does not output $ FF, the reference value is determined to be 130% in step (4).

When the reference value is set to $ 000 in step (6), the processor 50 sets the density data to $ FF in step (7).
If the A / D conversion circuit 67 sends out $ FF,
Since the density is 70% or less in step (11) and it is too thin, liquid toner is replenished and the process returns to step (6).

Then, in step (7), the concentration data is $ F.
If it is not F, it is checked in step (8) whether the concentration data is $ 00. When the A / D conversion circuit 67 does not send out $ 00, the reference value is determined to be 70% in step (9).

When the A / D conversion circuit 67 sends out $ 00, C = $ 800, which is the intermediate value between the upper and lower reference values input in step (10), is set to the D / A conversion circuit. 66
To enter.

Then, the processor 50 checks in step (12) whether the density data is $ 00. Here, when the A / D conversion circuit 67 sends out $ 00, D / $ BFF which is an intermediate value between the upper and lower two reference values $ 800 and $ FFF input in step (19) is D / $ BFF. Input to the A conversion circuit 66, and if the density data is not $ 00 in step (12), step
Check whether the concentration data is $ FF in (13).

In step (13), the A / D conversion circuit 67 sets $ F
When F is not sent, the reference value is 100% in step (14).
And the A / D conversion circuit 67 sets $ FF in step (13).
Is sent, E = $, which is an intermediate value between the upper and lower reference values $ 800 and $ 000 that were previously input in step (15).
The 3FF is input to the D / A conversion circuit 66.

Then, in step (16), the density data is $ 0.
If not 0 and the density data is not $ FF in step (17), the reference value is determined to be 85% in step (18). or,
When the reference value is set to $ BFF in step (19), step (2
In 0), it is checked whether the density data is $ 00. If it is not $ 00, it is checked in step (21) whether the density data is $ FF. If it is not $ FF, the reference value is determined to be 115% in step (22).

Even with this, the reference value is not obtained, and the step
When the A / D conversion circuit 67 sends out $ 00 in (16), the two upper and lower reference values $ 80 input in the previous step in Step (35).
H = $ 5FF, which is an intermediate value between 0 and $ 3FF, is input to the D / A conversion circuit 66, and the density data is $ 00 in step (36).
If it is not $ 00, it is checked in step (37) whether the concentration data is $ FF.

If the density data is not $ FF in step (37), the reference value is determined to be 92.5% in step (38), and whether the density is $ 00 in step (36) or in step (38). If the density data is $ FF, the operation of inputting the intermediate value of the upper and lower two reference values previously input to the D / A conversion circuit 66 is repeated, and the XXX% obtained in step (39) is used as the reference value. decide.

Further, when the A / D conversion circuit 67 sends out $ FF in the step (17), it is an intermediate value between the upper and lower two reference values $ 000 and $ 3FF inputted in the step (31). Input J = $ 1FF to the D / A conversion circuit 66 and step
In (32), check if the concentration data is $ 00. If it is not $ 00,
In step (33), it is checked whether the density data is $ FF.

If the density data is not $ FF in step (33), the reference value is determined to be 77.5% in step (34), and whether the density is $ 00 in step (32) or in step (33). If the density data is $ FF, the operation of inputting the intermediate value of the upper and lower two reference values previously input to the D / A conversion circuit 66 is repeated, and the XXX% obtained in step (39) is used as the reference value. decide.

When the A / D conversion circuit 67 sends out $ 00 in step (20), it is the intermediate value between the upper and lower two reference values $ FFF and $ BFF input in step (23). Input F = $ F55 to the D / A conversion circuit 66, and step
In (24), check if the concentration data is $ 00. If it is not $ 00,
In step (25), check whether the concentration data is $ FF.

If the density data is not $ FF in step (25), the reference value is determined to be 127.5% in step (26), and if the density is $ 00 in step (24) or in step (25). If the density data is $ FF, the operation of inputting the intermediate value of the upper and lower two reference values previously input to the D / A conversion circuit 66 is repeated, and the XXX% obtained in step (39) is used as the reference value. decide.

When the A / D conversion circuit 67 sends out $ FF in step (21), it is the intermediate value between the upper and lower two reference values $ 800 and $ BFF input in step (27). Input G = $ 9FF to the D / A conversion circuit 66 and step
In (28), check if the concentration data is $ 00. If it is not $ 00,
In step (29), it is checked whether the concentration data is $ FF.

If the density data is not $ FF in step (29), the reference value is determined to be 107.5% in step (30) and whether the density is $ 00 in step (28) or in step (29). If the density data is $ FF, the operation of inputting the intermediate value of the upper and lower two reference values previously input to the D / A conversion circuit 66 is repeated, and the XXX% obtained in step (39) is used as the reference value. decide.

5) The processor 50 is the operator panel 6
By reading the value of the DIP switch provided in 1, execute the reference value determination method described in 3),
It is determined whether to execute the reference value determination method described in 4).

6) The processor 50 sets a program counter set in the RAM 52 when the power is turned on and when measuring the toner density, and the program counter counts a predetermined time, for example, 10 seconds. During this period, the circulation pump 23 is driven to circulate the developing solution, and then the toner concentration measured by the concentration measuring circuit 58 is stored in the RAM 52.

Therefore, the toner concentration in the developer tank 22 shown in FIG. 9, the toner concentration in the developer tank 18, and the toner concentration of the developer 17 between the work support bed 20 and the electrode plate 19 are the same. Therefore, the toner concentration of the developer 17 can be measured by the concentration detected by the concentration sensor 36.

7) As described above, the processor 50 measures the toner density, and if the toner density deviates from the toner density to be maintained, the processor 50 drives the toner pump 25 if the density is low, and a predetermined amount of liquid toner is discharged. After replenishment, if the concentration is high, the solvent pump 27 is driven to replenish a predetermined amount of isopa, then the circulation pump 23 is driven for 10 seconds, and then the toner concentration is measured again.

Therefore, the replenished liquid toner or isopa mixes in the developer tank 22 and becomes a developer having a uniform concentration. Therefore, the toner concentration of the developer 17 is constant at the concentration detected by the concentration sensor 36 as described above. Can be

8) As described above, the processor 50 measures the toner density, and if the toner density deviates from the toner density to be maintained, if the density is low, the toner pump 25 is set to, for example, 2.
The toner is re-measured after being driven for 2 seconds to replenish the liquid toner, and when the concentration is high, the solvent pump 27 is driven for 4 seconds to replenish the isopa, and then the circulation pump 23 is driven for 10 seconds.

Therefore, the time for uniformizing the developing solution can be made substantially the same when the toner density is reduced and when it is increased. FIG. 6 is a diagram illustrating an example of the table.

FIG. 6 shows how to change the replenishment amount of the liquid toner or isopa and the driving time of the circulation pump according to the deviation amount of the toner concentration from the reference value. 9) and 10) The processor 50 uses the A in FIG.
If D / A conversion circuit 67 or $ 80 is being sent, D / A
It is determined that the toner concentration matches the reference value input to the conversion circuit 66, and the toner pump 25 and the solvent pump 27 are not driven.

However, when the toner density deviates from the reference value, the (reference value-density value) column of the table 47 shown in FIG. 6 is referred to, and if the deviation amount is (-1%), ( Referring to the columns of (toner replenishment time) and (circulation time), the toner pump 25 is driven for 2 seconds and the circulation pump 23 is set to 1
Drive for 0 seconds.

The deviation amount of the toner density is (-2%)
Then, while driving the toner pump 25 for 4 seconds,
The circulation pump 23 is driven for 15 seconds. If the deviation amount of the toner density is (+ 1%), the table 47 shown in FIG.
Refer to the columns of (Isopa replenishment time) and (Circulation time) of
The solvent pump 27 is driven for 4 seconds, and the circulation pump 23 is driven for 10 seconds.

Then, the toner density deviation amount is (+ 2%)
Then, the solvent pump 27 is driven for 8 seconds and the circulation pump 23 is driven for 15 seconds. 11) The processor 50 reads the numerical value of the DIP switch input from the operator panel 61, and refers to the table 47 to recognize whether the density is adjusted or the density is adjusted according to a predetermined value.

When referring to the table 47,
When the density adjusting method described in 9) and 10) above is executed and the density is adjusted with a predetermined value, the density adjusting method described in 7) above is executed.

FIG. 7 is a flow chart for explaining the processing when the toner density exceeds the specified value. 12) The processor 50 uses the circulation pump 23 in step (1).
Is driven, the program counter set in the RAM 52 is set, and 10 seconds are monitored in step (2).

After 10 seconds have passed, the density value is read in step (3), and the density data is converted to $ in step (4).
Check 00. Then, the A / D conversion circuit 67 shown in FIG.
Sends $ 00, the solvent pump 27 is used in step (5).
Drive and return to the process of step (3).

If the A / D conversion circuit 67 does not output $ 00 in step (4), it is checked in step (6) whether the density data is $ FF. Then, the A / D conversion circuit 67 outputs $ F
When F is sent, the toner pump 25 is driven in step (7), and the process returns to step (3).

The processor 50 executes A / in step (6).
If the D conversion circuit 67 does not output $ FF, it is determined that the toner concentration is within the range of the specified value with respect to the reference value, and the drive of the solvent pump 27 or the toner pump 25 is stopped in step (8).

That is, when the solvent pump 27 is driven, the solvent pump 27 is stopped and the toner pump 2
When 5 is driven, the toner pump 25 is stopped.

Then, in step (9), the driving of the circulation pump 23 is stopped. 13) Whether the processor 50 reads the numerical value of the DIP switch input from the operator panel 61 and adjusts the density while measuring the toner density, or whether the density is adjusted by replenishing liquid toner or isopa of a predetermined value. Recognize.

When the density adjustment is performed while the toner density is being measured, the density adjustment method described in the above 12) is executed and the density adjustment is performed by replenishing the liquid toner or isopa of a predetermined value. The density adjustment method described in 7) above is executed.

14) When the lower surface sensor 35 detects that the liquid level in the developer tank 22 has passed the lower limit, the processor 50
When the solvent pump 27 is driven and the lower surface sensor 35 notifies that the liquid level in the developer tank 22 has risen above the lower limit, the circulation pump 23 is driven for 10 seconds and then the toner concentration is measured. Is deviated from the reference value by the specified value or more, the toner pump 25 is driven when the density is low,
When the toner density falls within the specified value, the driving of the toner pump 25 is stopped.

15) The processor 50 does not constantly measure the toner density, but at a predetermined time point, that is, when the power is turned on, when the operator panel 61 issues an initial operation instruction, and when the developing section is operated. The cleaning pump 29 is driven to clean the material supply roller 30 and the squeeze roller 31 at the time of preparation for starting the development when the first work transfer is notified to the exposure unit 2 from the exposure unit 3, and after the work 11 is transferred to the drying unit 4. At the 5th point of completion, the circulation pump 23 is driven for 10 seconds, and then the output of the density measuring circuit 58 is read to measure the toner density.

If the toner density is measured at the five time points, the toner density between the time points is stable, and there is no problem in practically controlling the toner density. However, when the power is turned on, two minutes are allowed until the density sensor 36 becomes stable, the reference value is input as described above, and the measurement of the toner density is started.

16) The processor 50 reads the numerical value which is input from the operator panel 61 and indicates the toner density measurement time point, and the designated time point is read as R.
Store in AM52.

When the processing of the processor 50 arrives at the time of reading from the RAM 52, the circulation pump 23 is set to 1
After driving for 0 seconds, the output of the density measuring circuit 58 is read to measure the toner density.

17) When the switch 62 sends the output of the DIP switch of the operator panel 61, the processor 50 drives the circulation pump 23 for 10 seconds at the time point described in 16), and then outputs the output of the concentration measuring circuit 58. Is read to measure the toner density, and if the switch 62 sends out the ground potential, for example, at the time point described in 15), 1
After driving the circulation pump 23 for 0 seconds, the concentration measuring circuit 58
Read the output of and measure the toner density.

[0138]

As described above, the present invention speeds up the determination of the reference value input to the density measuring circuit, so that the toner density control time is shortened and the toner density is fixed within the effective density range. Because it does not match the value,
It is possible to eliminate unnecessary toner concentration control.

Further, the developing solution in the developing solution tank is further poured through the developing solution tank between the work supporting bed and the electrode plate to develop the latent image of the work, and the circulation pump is driven for a predetermined time. It is possible to shorten the time required to make the toner concentration uniform.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating the principle of the present invention.

FIG. 2 is a block diagram of a circuit showing an embodiment of the present invention.

FIG. 3 is a block diagram showing an example of a concentration measuring circuit.

FIG. 4 is a flowchart (part 1) illustrating an example of reference value setting.

FIG. 5 is a flowchart (part 2) illustrating an example of reference value setting.

FIG. 6 is a diagram illustrating an example of a table.

FIG. 7 is a flowchart illustrating processing when toner density exceeds a specified value.

FIG. 8 is a diagram illustrating an example of an automatic plate making device.

FIG. 9 is a diagram illustrating a configuration of a developing unit.

[Explanation of symbols]

 1 Plate feeding section 2 Exposure section 3 Developing section 4, 9 Drying section 5 Fixing section 6 Cooling section 7 Elution section 8 Gum section 10 Storage case 11 Work 12 Pickup device 13 Charger 14, 47 Table 15 Polygon mirror 16 Ground terminal 17 Development Liquid 18 Developer tank 19 Electrode plate 20 Work support bed 21 Liquid recovery tray 22 Developer tank 23 Circulation pump 24 Liquid toner tank 25 Toner pumps 26, 28 Solvent tank 27 Solvent pump 29 Cleaning pump 30 Feed roller 31 Squeeze roller 32 Weir 33 developer discharge port 34 upper surface sensor 35 lower surface sensor 36 concentration sensor 40 printing device 41 control means 42 concentration measuring means 43 toner solution replenishing means 44 solvent replenishing means 45 instructing means 46 developing solution circulating means 48 liquid amount detecting means 49 selecting means 50 Processor 51 ROM 52 RAM 53 Interface circuit 54 I / O ports 55, 56, 57, 63, 64 Drive circuit 58 Concentration measurement circuit 59, 60 Amplification circuit 61 Operator panel 62 Switch 65 Motor 66 D / A conversion circuit 67 A / D conversion circuit 68, 69, 70 Operational amplifier

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Takuma 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Nobuyuki Oshima 1015, Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (17)

[Claims] 1. A printing apparatus for developing a toner by adhering toner to a latent image formed on a print medium using a developing solution obtained by dissolving liquid toner in a solvent, and a density measuring unit for measuring the toner density of the developing solution. A toner replenishing means for replenishing the liquid toner; a solvent replenishing means for replenishing the solvent; and a toner replenishing means or a solvent replenishing means based on a measurement result of the concentration measuring means to drive the liquid toner. Alternatively, a control unit for replenishing the solvent is provided, and the toner concentration when the power is turned on is used as a reference, and the toner concentration that is the reference is maintained until the power is turned off. 2. A printing apparatus for developing a toner by adhering toner to a latent image formed on a print medium using a developing solution obtained by dissolving liquid toner in a solvent, and a density measuring unit for measuring the toner density of the developing solution. A toner replenishing means for replenishing the liquid toner; a solvent replenishing means for replenishing the solvent; and a toner replenishing means or a solvent replenishing means based on a measurement result of the concentration measuring means to drive the liquid toner. Alternatively, a control means for replenishing the solvent and an instruction means for instructing a toner concentration control method of the control means are provided, and the control means is made to maintain the toner concentration at power-on, or the designated toner concentration is maintained. A printing device characterized by instructing whether or not to perform. 3. A density measurement which reads the toner concentration of a developing solution obtained by dissolving a liquid toner in a solvent based on an input reference value, and indicates whether or not the amount of deviation from the reference value is within a specified value range. When the input reference value is within the effective range of the toner density, a printing device that develops the latent image formed on the printing medium with the developer, the measurement result of the density measuring means A control means for changing the input reference value based on the above is provided, and the result of the density measurement based on the reference value input to the density measurement means is such that the deviation amount from the reference value is outside the range of the specified value and the toner density is high. If the reference value is displaced from the reference value, the reference value is shifted in the darker direction of the toner density by a predetermined value and then the density measurement is repeated, and the result of the density measurement is deviated from the reference value. amount If the toner density deviates in the light toner density direction outside the specified value range, the reference value is shifted in the light toner density direction by a predetermined value, and the density measurement is repeated. A printing apparatus, wherein the toner density measured based on the inputted reference value is searched for within the effective range of the toner density. 4. A density measurement which reads the toner concentration of a developer obtained by dissolving liquid toner in a solvent based on an input reference value, and indicates whether or not a deviation amount from the reference value is within a specified value range. When the input reference value is within the effective range of the toner density, a printing device that develops the latent image formed on the printing medium with the developer, the measurement result of the density measuring means Control means for changing the input reference value based on the above, the reference value input to the density measuring means is set to the maximum value A and the minimum value B of the effective range of the toner density, and then the input reference value is set to ( A + B) / 2 = C, then the input reference values are (C + A) / 2 = D and (C + B) / 2 = E, and then the input reference values are (A + D) / 2 = F and ( D + C) / 2 = G and (C + E) / 2 H and (E +
B) / 2 = J Always obtain the intermediate value between the two upper and lower reference values that were previously input and input the value, and repeat the density measurement process, and the toner density measured based on the input reference value is A printing apparatus that searches for the reference value within an effective range of toner density. 5. A density measurement which reads the toner concentration of a developing solution obtained by dissolving liquid toner in a solvent based on an input reference value, and indicates whether or not the amount of deviation from the reference value is within a specified value range. When the input reference value is within the effective range of the toner density, a printing device that develops the latent image formed on the printing medium with the developer, the measurement result of the density measuring means Control means for changing the input reference value based on the above, and instruction means for instructing the concentration measuring means how to change the reference value input by the control means, and sequentially shifting the reference value by a predetermined value. A printing apparatus, characterized by inputting or specifying an intermediate value between two upper and lower reference values input previously and inputting. 6. A developing solution in which liquid toner is dissolved in a solvent is stored in a developing solution tank, and the developing solution is poured into a print medium through a developing solution tank by a developing solution circulating means and then refluxed to the developing solution tank. Then, in a printing device that develops toner by adhering toner to a latent image formed on the print medium, a concentration measuring unit that measures the toner concentration of the developer, a control unit that controls the developer circulating unit, And a toner concentration in the developer tank is measured after the developer circulating means is driven for a predetermined time when the power is turned on or before the toner concentration is measured. 7. A developing solution in which liquid toner is dissolved in a solvent is stored in a developing solution tank, and the developing solution is poured into a print medium through a developing solution tank by a developing solution circulating means and then refluxed to the developing solution tank. Then, in a printing device for developing a toner by adhering toner to a latent image formed on the print medium, a concentration measuring unit for measuring a toner concentration of the developer, and a toner liquid replenishing unit for replenishing the liquid toner, Solvent replenishing means for replenishing the solvent, and driving the toner liquid replenishing means or the solvent replenishing means based on the measurement result of the concentration measuring means to replenish the developer tank with a predetermined amount of the liquid toner or solvent. A control means for controlling the developing solution circulating means, and when driving the toner replenishing means or the solvent replenishing means, after driving the developing solution circulating means for a predetermined time,
A printing apparatus for measuring the toner concentration in the developer tank. 8. A developer in which liquid toner is dissolved in a solvent is stored in a developer tank, and the developer is circulated to the print medium through a developer tank by a developer circulating means and then refluxed to the developer tank. Then, in a printing device for developing a toner by adhering toner to a latent image formed on the print medium, a concentration measuring unit for measuring a toner concentration of the developer, and a toner liquid replenishing unit for replenishing the liquid toner, The solvent replenishing means for replenishing the solvent, and the toner liquid replenishing means or the solvent replenishing means are driven based on the measurement result of the concentration measuring means to replenish the liquid toner or the solvent in the developing solution tank, and A control means for controlling the liquid circulation means is provided, and the amount of the liquid replenished by the toner liquid replenishing means at one time is smaller than the amount of the liquid replenished by the solvent replenishing means at a time. Printing apparatus being characterized in that the same driving time of the developer circulation means before measurement. 9. A developing solution in which liquid toner is dissolved in a solvent is stored in a developing solution tank, and the developing solution is poured into a print medium through a developing solution tank by a developing solution circulating means and then refluxed to the developing solution tank. Then, in a printing device for developing a toner by adhering toner to a latent image formed on the print medium, a concentration measuring unit for measuring a toner concentration of the developer, and a toner liquid replenishing unit for replenishing the liquid toner, The solvent replenishing means for replenishing the solvent is referred to, and the toner liquid replenishing means or the solvent replenishing means is driven by referring to a table indicating a preset replenishing amount of the liquid toner and the solvent from the measurement result of the concentration measuring means. While replenishing the liquid toner or solvent in the developer tank,
A control means for controlling the developing solution circulation means; and a larger amount of the liquid toner or solvent to be replenished as the amount of deviation of the toner concentration from the reference value to be maintained is larger. apparatus. 10. A developing solution in which liquid toner is dissolved in a solvent is stored in a developing solution tank, and the developing solution is poured into a print medium through a developing solution tank by a developing solution circulating means and then refluxed to the developing solution tank. Then, in a printing device for developing a toner by adhering toner to a latent image formed on the print medium, a concentration measuring unit for measuring a toner concentration of the developer, and a toner liquid replenishing unit for replenishing the liquid toner, The solvent replenishing means for replenishing the solvent is referred to, and the toner liquid replenishing means is referred to a table for instructing a replenishing amount of the liquid toner and the solvent and a driving time of the developing solution circulating means which are preset from the measurement result of the concentration measuring means. Means or solvent replenishing means to replenish the developing solution tank with the liquid toner or solvent, and control means for controlling the developing solution circulating means. The larger the amount of deviation from the reference value to be lifting, printing apparatus characterized by lengthening the time for driving the developer circulation means. 11. A developing solution in which liquid toner is dissolved in a solvent is stored in a developing solution tank, and the developing solution is poured into a print medium through a developing solution tank by a developing solution circulating means and then refluxed to the developing solution tank. Then, in a printing device for developing a toner by adhering toner to a latent image formed on the print medium, a concentration measuring unit for measuring a toner concentration of the developer, and a toner liquid replenishing unit for replenishing the liquid toner, The solvent replenishing means for replenishing the solvent is referred to, and the toner liquid replenishing means is referred to a table for instructing a replenishing amount of the liquid toner and the solvent and a driving time of the developing solution circulating means which are preset from the measurement result of the concentration measuring means. Means or solvent replenishing means to replenish the developer tank with the liquid toner or solvent, and control means for controlling the developer circulating means, and the control means with the table. When the table is referred to, there is provided an instruction means for instructing whether or not to refer to the table. In addition to increasing the number of times, the time for driving the developing solution circulating means is lengthened, and when the table is not referred to, the liquid toner or the solvent is replenished with a predetermined value, and the developing solution circulating means is driven with a predetermined value. A printing device characterized by. 12. A developer solution in which liquid toner is dissolved in a solvent is stored in a developer tank, and the developer solution is poured into a print medium through a developer tank by a developer circulating means and then refluxed to the developer tank. Then, in a printing apparatus for developing toner by adhering toner to a latent image formed on the print medium, the toner concentration of the developer in the developer tank is read based on the input reference value, and the read value from the reference value is read. From the measurement result of the concentration measuring means, which expresses whether or not the amount of deviation is within a specified range, the toner liquid replenishing means that replenishes the liquid toner, the solvent replenishing means that replenishes the solvent, and the concentration measuring means. A control means for driving the toner solution replenishing means or the solvent replenishing means to replenish the developing solution tank with the liquid toner or solvent and controlling the developing solution circulating means is provided. When the toner is thin beyond the specified value range of the step, the toner concentration is measured while driving the toner liquid replenishing means and the developer circulating means, and the toner concentration is within the specified value range of the concentration measuring means. At this time, the toner solution replenishing means and the developing solution circulating means are stopped, and when the toner concentration is higher than the specified value range of the concentration measuring means, the solvent replenishing means and the developing solution circulating means are driven. A printing apparatus, which measures a toner density and stops the solvent replenishing means and the developer circulating means when the toner density falls within a range of a specified value of the density measuring means. 13. A method of storing a developing solution in which a liquid toner is dissolved in a solvent in a developing solution tank, pouring the developing solution onto a print medium through a developing solution tank by a developing solution circulating means, and then refluxing it to the developing solution tank. Then, in a printing apparatus for developing toner by adhering toner to a latent image formed on the print medium, the toner concentration of the developer in the developer tank is read based on the input reference value, and the read value from the reference value is read. From the measurement result of the concentration measuring means, which expresses whether or not the amount of deviation is within a specified range, the toner liquid replenishing means that replenishes the liquid toner, the solvent replenishing means that replenishes the solvent, and the concentration measuring means. Driving the toner liquid replenishing means or solvent replenishing means to replenish the developer tank with the liquid toner or solvent, and controlling the developer circulating means, and the control means with the liquid toner or solvent. To shorten the replenishment time of the liquid toner or solvent by providing an instruction means for instructing whether to measure the toner concentration after replenishing a fixed amount or to replenish the liquid toner or solvent while measuring the toner concentration, A printing apparatus, wherein the toner concentration is measured after the liquid toner or solvent is replenished while the measurement is performed and the replenishment amount of the liquid toner or solvent is reduced. 14. A developing solution in which liquid toner is dissolved in a solvent is stored in a developing solution tank equipped with a solution amount detecting means for detecting the amount of the developing solution, and the developing solution is circulated through a developing solution tank. In a printing apparatus for developing a toner by adhering toner to a latent image formed on the print medium by pouring the developer onto the print medium and then refluxing the solution into the developer tank, A toner concentration reading unit that reads the toner concentration based on an input reference value and indicates whether a deviation amount from the reference value is within a specified value range; a toner liquid replenishing unit that replenishes the liquid toner; Solvent replenishing means for replenishing the solvent, and driving the toner liquid replenishing means or the solvent replenishing means from the measurement result of the concentration measuring means and the detection result of the liquid amount detecting means, so that the liquid toner or solvent is added to the developer tank. Together with replenishing And control means for controlling the developer circulation means, provided, if the amount of the developing solution of the developer tank is reduced below a predetermined value, after supplemented the solvent until a predetermined value,
A printing apparatus, characterized in that a toner concentration is measured and a required amount of liquid toner is replenished. 15. A developing solution in which liquid toner is dissolved in a solvent is stored in a developing solution tank, and the developing solution is poured into a print medium through a developing solution tank by a developing solution circulating means and then refluxed to the developing solution tank. In a printing apparatus for developing toner by adhering toner to a latent image formed on the print medium, density measuring means for measuring the toner density of the developer in the developer tank, and density measuring by the density measuring means A printing apparatus, which is provided with a control means for instructing start and controlling the developing solution circulating means, and performing density measurement after circulating the developing solution for a predetermined time at a predetermined time point. 16. A method of storing a developing solution in which liquid toner is dissolved in a solvent in a developing solution tank, pouring the developing solution into a print medium through a developing solution tank by a developing solution circulating means, and then refluxing the developing solution tank. In a printing apparatus for developing toner by adhering toner to a latent image formed on the print medium, density measuring means for measuring the toner density of the developer in the developer tank, and density measuring by the density measuring means A control means for instructing the start and controlling the developer circulating means, and an instruction means for instructing the control means at the time point of starting the concentration measurement are provided, and at the time point instructed by the instructing means, the developer is kept for a predetermined time. A printing apparatus characterized by performing density measurement after circulating the ink. 17. A developing solution in which liquid toner is dissolved in a solvent is stored in a developing solution tank, and the developing solution is poured into a print medium through a developing solution tank by a developing solution circulating means and then refluxed to the developing solution tank. In a printing apparatus for developing toner by adhering toner to a latent image formed on the print medium, density measuring means for measuring the toner density of the developer in the developer tank, and density measuring by the density measuring means At the same time as instructing the start, the control means for controlling the developer circulating means, the instructing means for instructing the control means at the time point of starting the concentration measurement, and the concentration measurement at the predetermined time point by the instruction of the instructing means. The control means is provided with a selection means for selecting whether or not to start, and at the time point instructed by the instruction means, the developer is circulated for a predetermined time and then the concentration is measured, or when a predetermined time is determined. In the printing apparatus, characterized in that the density measurement after circulating predetermined time developer.