JPH0463386A - Fixability evaluating device - Google Patents

Abstract

PURPOSE:To evaluate the fixability of toner by catching recording paper and a transfer sheet between a pair of test rolls and measuring the change between the toner density on recording paper before transfer to the transfer sheet and that after transfer to the transfer sheet. CONSTITUTION:A transfer sheet 3 is placed on recording paper 2 to which toner 1 is fixed, and recording paper 2 and the sheet 3 are caught between test rolls 5 and 6. The roll 5 can be rotated in both directions and its rotation speed can be adjusted, and the roll 6 can be rotated while following up the roll 5 and its following-up rotation can be forcibly stopped. The transfer image density on the sheet 3 to which toner 1 is transferred is measured by a sensor, and the transfer rate is obtained by the initial density on recording paper 2, to which toner 1 is fixed, and the transfer image density in accordance with (transfer rate (%))=(transfer image density)/(initial density)X100.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fixing performance evaluation device used to evaluate the fixing performance of toner fixed on recording paper, and in particular, to The present invention relates to a fixability evaluation device that enables accurate evaluation of toner fixability to recording paper.

U Prior Art and its Problems] Conventionally, in electrophotographic devices such as copying machines and printers, in order to prevent the toner image fixed on the recording paper from easily peeling off from the recording paper, The fixing properties of the toner fixed on the paper were evaluated, and based on this, various fixing conditions such as fixing pressure, fixing temperature, and fixing speed were determined when fixing the toner to recording paper using a fixing roller, etc. .

Conventionally, when evaluating the fixing properties of toner fixed on recording paper, it is necessary to The fixation of toner on recording paper is evaluated by examining the state of peeling.For example, various test methods such as bending test method, mending tape peeling method, eraser test method, etc. I was trying to evaluate gender.

Here, in the above-mentioned bending test method, generally, solid black recording is performed on recording paper, and this is JISP8111r
After pre-processing the test paper, bend the center of the solid black recording part lightly, roll a 1 kg cylindrical weight over this crease, fold the recording paper, and then open the fold. After lightly rubbing the crease with a cloth and wiping off the toner that fell off, the degree of whiteness of the crease was compared with that of a sample to determine the toner fixability.

In addition, in the mending tape peeling method, similarly to the above-mentioned bending test method, after performing solid black recording on the recording paper and pre-treating it, the recording section is After measuring the initial density of the mainding tape, lightly pasting the mainding tape on top of this solid black recording area and slowly moving a 1 kg cylindrical weight twice over the tape, the mainding tape was was peeled off at an angle of 180 degrees to the recording surface, the residual concentration at the peeled place was measured, and the following [1]
The fixation rate (%) was calculated using the formula to evaluate the fixability of the toner to the recording paper.

In the eraser test method, generally, a solid black record is made on recording paper, the initial density of this recorded area is measured, and then an eraser is used to rub the recorded area with a constant pressure a certain number of times. Measure the residual density in the rubbed area, calculate the fixation rate using the above formula [1], as in the case of the mending tape peeling method described above,
The fixability of toner to recording paper was evaluated.

However, all of the above-mentioned test methods that have been conventionally used to evaluate toner fixability on recording paper evaluate toner fixation when a specific load is applied to recording paper. However, it is not possible to comprehensively evaluate the toner fixing performance in response to the various loads that are actually applied to the recording paper on which the toner image is fixed. There has been a problem in that it is not possible to accurately evaluate the fixability of the toner with respect to offset stains such as smear, which is transferred to other paper or the like due to contact or friction.

In addition, in the conventional testing methods described above, there are many parts that are operated by humans, making the testing itself troublesome and making it difficult to standardize the testing conditions. Yes, measurement results tend to vary;
The problem is that it is difficult to accurately evaluate the fixability of toner on recording paper, and in particular, it is not possible to accurately evaluate subtle changes in fixability when the density of the toner image fixed on recording paper is high. was there.

[Problems to be Solved by the Invention] It is an object of the present invention to solve the above-mentioned problems when evaluating the fixability of toner fixed on recording paper.

In other words, in evaluating the fixing properties of toner fixed on recording paper, the present invention can easily evaluate the fixing properties of toner by corresponding to various loads actually applied to the recording paper on which toner images are fixed. At the same time, there is little variation in the measurement results, and it is possible to accurately evaluate the fixation of toner on recording paper.In particular, it is possible to accurately evaluate the fixation of toner on recording paper. Fixability against offset stains such as smear,
It is an object of the present invention to provide a fixing performance evaluation device that can accurately evaluate subtle changes in fixing performance when the density of a toner image fixed on recording paper is high.

[Means for Solving the Problems] In order to solve the above-mentioned problems, in the present invention, as a fixing performance evaluation device that evaluates the fixing performance of toner fixed on recording paper, a fixing performance evaluation device that evaluates the fixing performance of toner fixed on recording paper is provided. A pair of test rollers are provided to sandwich the recording paper and the transfer sheet with the transfer sheet placed on the sheet, and at least one test roller in the pair of test rollers is provided so as to be able to rotate in both forward and reverse directions. At least the other test roller is provided so that it can be stopped so as not to rotate, and a pressure adjustment means is used to adjust the pressure contact force between the pair of test rollers.

Here, various types of paper or resin films for overhead projectors (OHP), etc. can be used as the transfer sheet placed on the recording paper on which the toner is fixed, and the recording paper is actually used. It should be selected and used as appropriate, taking into consideration the state and other factors.

In addition, the above pair of test rollers is designed to ensure a sufficient nip width when the recording paper and transfer sheet are sandwiched together, and to ensure that the movement of the recording paper and transfer sheet can be well controlled. It is preferable to use a material that has a high coefficient and has good adhesion to the recording paper or transfer sheet, such as a silicone rubber roller.

Furthermore, the above-mentioned test roller is provided with a temperature adjustment means such as a heater, and the temperature of the test roller is changed by this temperature adjustment means so that the fixing performance of the toner fixed on the recording paper can be evaluated under various temperature conditions. It is preferable to do so.

"Function: When evaluating the fixing properties of toner fixed on recording paper using the fixing properties evaluation device according to the present invention, consider the conditions in which the recording paper is actually used, etc., and select the transfer sheet to be used. The transfer sheet is placed on the recording paper to which the toner is fixed, and the recording paper and the transfer sheet are sandwiched between the pair of test rollers.

In addition, the conditions for driving each of the test rollers mentioned above and the pressure contact force between the test rollers by the pressure adjustment means were adjusted so that a load corresponding to the conditions in which the recording paper was actually used was applied, and this test was conducted. The toner fixed on the recording paper is transferred to the transfer sheet between the rollers.

Then, the change in the toner image density on the recording paper before the toner fixed on the recording paper is transferred to the transfer sheet and the toner image density on the recording paper after the transfer is measured, or The image density of the toner transferred to the sheet is measured to evaluate the fixability of the toner fixed to the recording paper.

Note that when measuring the image density of the toner on the recording paper after transfer as described above, the measurement results may be affected by changes in the gloss of the toner due to rubbing with the transfer sheet, or by the filling of the toner. Since there is a risk that the evaluation of the fixability of the toner to the recording paper may be incorrect, it is recommended to measure the image density of the toner transferred to the transfer sheet and evaluate the fixability of the toner to the recording paper. preferable.

[Example] Hereinafter, a fixing performance evaluation device according to an example of the present invention will be specifically described based on the accompanying drawings.

In this example, as shown in FIGS. 1 and 2, toner (1) is fixed on the recording paper (2), and toner (1) is fixed on the transfer sheet (3). It was placed on the recording paper (2) so as to be in contact with the surface.

Here, as the transfer sheet (3) placed on the recording paper (2) as described above, the toner ( 1
), prepare various types of paper and resin films for overhead projectors (OHP), and select and use the appropriate transfer sheet (3) each time. did.

Then, with an appropriate transfer sheet (3) placed on the recording paper (2) to which the toner (1) has been fixed as described above, the recording paper (2) and the transfer sheet (3) are transported. Belt (4
) and the conveyor belt (4) transports the recording paper 2) and the transfer sheet (3) to a pair of test rollers (
5. (6) Introduce toner 1) as shown in Figure 3.
With the transfer sheet (3) placed on the recording paper (2) on which has been fixed, the recording paper (
2) and the transfer sheet (3) were sandwiched between them.

In this way, the recording paper (2) and the transfer sheet (3) are conveyed by the conveyor belt (4) to a pair of test rollers (5).

(6) When guiding between the two, the conveyor belt (4) should be linked with the test roller (6) located below,
The conveyor belt (4) is driven as the test roller (6) located below rotates, and the recording paper (2) and transfer sheet (3) are
was guided between the pair of test rollers (5) and (6).

In addition, a silicone rubber roller is used for each of the test rollers (5) and (6), and each of the test rollers (5) and (6) that sandwich the recording paper (2) and transfer sheet (3) are used.
6) in a part other than the central part of the test roller (5),
(6) In order to prevent the friction between them from increasing due to mutual contact, each test roller (5), (6) has a recording paper (2) and a transfer sheet (as shown in FIG. 4). 3) Use a sheet whose diameter is smaller at both sides that do not sandwich the recording paper (2) and transfer sheet (3) than the diameter at the center where they are sandwiched.

The test roller (5) located at the top can rotate in both forward and reverse directions and its rotation speed can be adjusted, while the test roller (6) located at the bottom can rotate in both forward and reverse directions. It is made to be able to rotate following the test roller (5), and also to forcibly stop this driven rotation.

In addition, a pressure adjusting means (not shown) such as an air cylinder is provided for the pair of test rollers (5) and (6),
This pressure adjustment means adjusts the pressure contact force between the test rollers (5) and (6) that sandwich the recording paper (2) and transfer sheet (3), and this pressure contact force is measured using a pressure gauge (not shown). It was possible to evaluate the fixability of the toner (1) to the recording paper (2) under various pressure conditions.

Furthermore, in this example, a temperature adjustment means (not shown) such as a heater is provided in these test rollers (5) and (6), and the recording paper (2) is heated by this temperature adjustment means.
) and a test roller (5) that sandwiches the transfer sheet (3),
By adjusting the temperature of (6) and measuring this temperature with a temperature sensor (not shown), it is possible to evaluate the fixability of toner (1) to recording paper (2) under various temperature conditions. I did it like that.

Then, as described above, the recording paper (2
) and the transfer sheet (3), and at the same time adjust the pressure between the recording paper (2) and the transfer sheet (3) using the temperature adjusting means.
), and with the transfer sheet (3) placed on the recording paper (2) to which the toner (1) has been fixed, (5)
, (6) After sandwiching the recording paper (2) and transfer sheet (3), adjust the rotation speed of the test roller (5) located above, and then rotate the test roller (5) in the correct position. The test roller (6) located at the bottom is rotated appropriately in the direction, reverse direction, forward and reverse directions, and the test roller (6) located at the bottom is rotated appropriately.
According to 5), the motor is driven to rotate or forced to stop.

In this way, the above test roller (
Through steps 5) and (6), loads are applied to the recording paper (2) corresponding to various conditions in which it will actually be used, and the toner (1) fixed on the recording paper (2) is transferred to the transfer sheet (3). I tried to let them do it.

Then, the toner (
After transferring toner (1) to the transfer sheet (3), the image density of the toner (1) transferred to the transfer sheet (3) is measured by a density sensor (not shown), and then fixed on the recording paper (2). The fixing properties of the toner (1) were evaluated.

In addition, when measuring the density of the toner (1) transferred to the transfer sheet (3), after the transfer, the recording paper (
2) and the transfer sheet (3), and a density sensor is provided at an appropriate position on a conveyor belt (4) that conveys the transfer sheet (3) separated by the separating means. It is desirable to be able to automatically measure the image density of the toner (1) transferred to the transfer sheet (3).

Next, we will compare the fixing properties of the toner (1) fixed on the recording paper (2) using the fixing property evaluation device according to this example and the case where it was evaluated using a conventional eraser test. I decided to do so.

Here, in evaluating the fixability of the toner (1) fixed on the recording paper (2), the image density (ID) of the toner (1) fixed on the recording paper (2) is 1.2, 0.9,
0.6. The evaluation was conducted for four types of image densities of O14.

And for the four types of image densities like this,
In order to evaluate the fixability of toner (1) on each recording paper (2), prepare a large number of toners (1) with different fixing strengths on recording paper (2) for each image density. I did it like that.

In addition, when changing the fixing strength of toner (1) to recording paper (2), toner (1) is attached to recording paper (2).
The fixing pressure of the fixing roller (not shown) is set to 10
While keeping it constant at 0 kg, the fixing speed (mm/x) was changed to 50.150250 350 450.550, and the fixing temperature (°C) was 150,190°24
By changing it to 0, various fixing strengths were adjusted.

Here, in evaluating the fixing properties of toner (1) on each recording paper (2) whose fixing strength of toner < 1) has been adjusted in this way using the fixing properties evaluation apparatus according to this example, , Recording paper (2) as the above transfer sheet (3)
Using the same type of paper as above, place the transfer sheet (3) on the recording paper (2) to which the toner (1) has been fixed, then combine the recording paper (2) and the transfer sheet (3). was sandwiched between the pair of test rollers (5) and (6).

Then, the pressure contact force between the test rollers (5) and (6) was adjusted to 20 kg by the pressure adjusting means, and the nip width between the test rollers (5) and (6) was approximately 1
As shown in Fig. 5, the lower test roller (5) is forcibly fixed, while the upper test roller (5) is rotated at a rotational speed of 100 mm/sec. The roller (5) was rotated in both forward and reverse directions with a friction width of 10 mm to make 10 reciprocations, so that the toner (1) fixed on the recording paper (2) was transferred to the transfer sheet (3).

Next, the density of the transferred image on the transfer sheet (3) onto which the toner (1) has been transferred is measured using a density sensor, and the density of the transferred image on the transfer sheet (3) to which the toner (1) has been transferred is measured using a density sensor, and the density of the transferred image is measured on the original recording paper (2) on which the toner (1) has been fixed.
The transfer rate (%) shown in the following equation [2] was determined from the initial density in and the transferred image density.

[2] On the other hand, when evaluating the fixability of toner (1) on each recording paper (2) whose fixation strength of toner (1) has been adjusted as described above by a conventional eraser test, eraser comb (11 ), a sand eraser (Lion drawing eraser No. 502) was used.

Then, as shown in Figure 6, the sand eraser (11)
Hold this sand eraser (11) in the holder (12) so that the 90-degree corner is at a 45-degree angle to the above-mentioned recording paper (2) to which the toner (1) is fixed. , the above sand eraser (1) is inserted through this holder (12).
While applying 1 kg of force to 1) and pressing this sand eraser (11) onto the recording paper (2) on which toner (1) has been fixed, 1. : Place the sand eraser (11) on the recording paper (2) and make it reciprocate 3 times over a distance of 10 cm in 20 seconds per reciprocation.
The sand eraser (11) is used to peel off the toner (1) fixed on the recording paper (2).

Next, the toner (1) on the recording paper (2) after peeling off the toner (1) with the sand eraser (11) in this way is removed.
Measure the residual density of toner (1) and compare this residual density with toner (1).
The fixing rate (%) shown in equation 12 above was calculated from the initial density on the recording paper <2) on which the image was fixed.

Then, the correspondence between the transfer rate (%) determined using the fixing performance evaluation device according to this example and the fixing rate (%) determined by the above erasing comb test was fixed on the recording paper (2). Each image density (ID) of the toner (1) was examined, and the results were displayed with the transfer rate (%) on the vertical axis and the fixing rate (%) on the horizontal axis, as shown in FIG.

In addition, in the same figure, the image density (ID
) or 1.2, the solid line represents the correspondence between the transfer rate and fixation rate, the broken line represents the correspondence between the transfer rate and fixation rate in the case of 0.9, and the correspondence relationship between the transfer rate and fixation in the case of 0.6. The correspondence relationship between the transfer rate and the fixing rate in the case of 0.4 is shown as a dashed-dotted line, and the correspondence relationship between the transfer rate and the fixing rate in the case of 0.4 is shown as a dash-dotted line.

As is clear from this result, as the initial image density of the toner (1) fixed on the recording paper (2) increases,
The initial slope of the transfer rate relative to the fixing rate was large.

Therefore, even if the image density of the toner (1) fixed on the recording paper (2) is high, which may cause problems in actual use, in the conventional eraser comb test, there is almost no change in the fixation rate. However, it was not possible to accurately evaluate subtle changes in fixing properties, and the transfer rate determined using the fixing property evaluation device according to this example clearly showed changes in fixing properties. It is now possible to accurately evaluate fixing properties in accordance with actual use.

[Effects of the Invention] As detailed above, in the fixing performance evaluation device according to the present invention, the recording paper and the transfer sheet are placed on top of the toner fixed to the recording paper, and the recording paper and the transfer sheet are It is sandwiched between a pair of test rollers, and when evaluating the fixability of the toner fixed on the recording paper, the type of transfer sheet mentioned above must be selected to correspond to the conditions in which the recording paper will actually be used. At the same time, the conditions for driving the pair of test rollers and the pressure contact force between the test rollers by the pressure adjustment means are adjusted so that the toner fixed on the recording paper is transferred to the transfer sheet between the test rollers. did.

Then, the toner density change on the recording paper before and after the toner fixed on the recording paper is transferred to the transfer sheet is measured, or the image density of the toner transferred to the transfer sheet is measured. The fixability of the toner fixed on the recording paper was evaluated by measurement.

As a result, when the fixing performance evaluation apparatus according to the present invention is used, it has become possible to evaluate the toner fixing performance corresponding to various loads actually applied to recording paper on which a toner image is fixed.

In addition, when using the fixing property evaluation device according to the present invention, unlike conventional methods, there are many parts that must be operated by humans, making the test cumbersome, and it is not possible to make the test conditions constant. It is now possible to accurately evaluate the fixability of toner to recording paper, and in particular, toner fixation to recording paper due to contact or friction has been reduced. It is possible to accurately evaluate toner fixability against offset stains such as smear that is transferred to other paper, etc., and subtle changes in fixability when the density of the toner image fixed on recording paper is high. It became so.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing a state in which a recording paper and a transfer sheet are set in a fixing performance evaluation apparatus according to an embodiment of the present invention, and FIG. FIG. 3 is a schematic side view showing a state in which the recording paper and transfer sheet are sandwiched between a pair of test rollers in the same embodiment;
FIG. 4 is a front view of the test roller used in the same example, and FIG. 5 is a schematic diagram showing an example of driving the test roller with the recording paper and transfer sheet sandwiched between a pair of test rollers in the same example. 6 is a schematic side view showing a state in which the fixability of toner fixed to recording paper is evaluated by a conventional eraser test, and FIG. FIG. 3 is a diagram showing the correspondence between the determined specific fixing strength and the fixing strength determined by an eraser test. (1)...Toner <2)...Recording paper (3
)...Transfer sheet (5)...Test roller (upper side) (6)...Test roller (lower side) Fixing rate (%)

Claims (1)

[Claims] 1. With the transfer sheet placed on the recording paper to which the toner has been fixed, a pair of test rollers is provided to sandwich the recording paper and the transfer sheet, and at least one of the pair of test rollers is At least the other test roller is provided so as to be rotatable in both opposite directions, and at least the other test roller is
Provided so that it can be stopped so that it does not rotate,
The fixing performance evaluation device further comprises a pressure adjustment means for adjusting the pressure contact force between the pair of test rollers.