JPS6234620Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to an ink application device that applies liquid ink to a member to be coated, such as a film or a roller.

(Prior Art) Figures 1 to 4 relate to the prior art of the present invention.

An ink coating device having an ink presence/absence detecting means will be explained with reference to FIG. Reference numeral 1 denotes a film-like member to be coated, which includes a correction roller 2 and a back-up roller 4.
It is sandwiched between. The ink tank 5 is arranged so that the ink 3 therein can be drawn up by the correction roller 2. Reflective photoelectric element 6
is pumped up and placed at a position where the presence or absence of ink 3 adhering to the correction roller 2 can be detected. Here, the first part regarding the arrangement of the conventional reflective photoelectric element 6 will be explained.
To explain using FIG. 2 showing the A-A' cross section in the figure, the central axis F in the viewing direction of the reflective photoelectric element 6 is relative to the roller axis E-E' of the correction roller 2.
It is arranged so that −F′ is vertical. Further, the reflective photoelectric element 6 is wired as shown in FIG. 3 and inputted to the discriminator 7. When the film-like coating member 1 is conveyed in the direction of the arrow B by a means not shown in the ink coating device configured in this way, the correction roller 2 and the back-up roller 4 are moved in the directions of the arrows C and D, respectively. Rotate in the direction. As the correction roller 2 rotates, the ink 3 in the ink tank 5 is drawn up and applied to the film-shaped member 1 to be coated. When the ink 3 is attached to the surface of the correction roller 2, and when the ink 3 is attached to the surface of the correction roller 2,
The amount of light reflected from the light emitting part 6a of the reflective photoelectric element 6 is different when the surface of the straightening roller 2 disappears and the surface of the correction roller 2 appears, and therefore the amount of light reaching the light receiving part 6b is different. The voltages are also different. The purpose is to determine the presence or absence of ink 3 based on the voltage change between terminals H and G. However, when the ink 3 adheres to the surface of the correction roller 2, it does not adhere to the surface of the correction roller 2 in a uniform thickness, but in an irregular uneven shape. The surface of the ink 3 adhered in this uneven shape acts as a concave or convex reflective lens, and the light emitted from the light emitting part 6a of the reflective photoelectric element 6 is reflected very irregularly. The voltage between H and G output from the light receiving section 6b also changes irregularly due to the reflected light. This voltage change between H and G is expressed as
As shown in the figure. Section I is the voltage between H and G when there is ink 3, and section J is the voltage between H and G when there is no ink 3.
-G voltage.

In this manner, when the ink 3 is present, the voltage between H and G fluctuates irregularly, making it impossible to accurately determine the presence or absence of ink, which has the disadvantage of being impractical.

(Purpose of the invention) In order to solve this drawback, the purpose of the invention is to use a reflective photoelectric element as a means for detecting the presence or absence of ink, so that the central axis of the reflective photoelectric element in the viewing direction is perpendicular to the roller axis of the correction roller. The correction roller is arranged at an angle inclined from the direction of the correction roller, so that the presence or absence of ink on the surface of the correction roller can be reliably detected.

(Structure of the invention) A member to be coated in the form of a film or a roller, a straightening roller whose outer peripheral surface is closely engraved with linear grooves and pressed against the member to be coated, and a straightening roller attached to the straightening roller. In an ink coating apparatus equipped with an ink presence/absence detection means for detecting the presence or absence of ink in a liquid state, a reflective photoelectric element is used as the ink presence/absence detection means, and the central axis of the reflective photoelectric element in the viewing direction is aligned with the roller of the correction roller. Opposing the surface of the correction roller at an angle of about 30° to 60° from the axial direction,
This is a configuration in which the reflective photoelectric elements are arranged.

(Example) The present invention will be explained in detail below with reference to the drawings.

FIG. 5 is a diagram showing a first embodiment of the present invention, and shows a cross section taken along line A-A' in FIG. 2 is a correction roller; 6 is a reflective photoelectric element;
are arranged so as to be perpendicular to the central axis K-K' in the viewing direction and to the slope n of the linear groove carved on the outer peripheral surface of the correction roller 2. To explain the operation, FIG. 5 shows a case where there is no ink 3 on the surface of the correction roller 2, and the light emitted from the light emitting part 6a of the reflective photoelectric element 6 is engraved on the outer peripheral surface of the correction roller 2. The light is reflected in the direction of the arrow M1 by the slope n of the groove, and reaches the light receiving part 6b of the reflective photoelectric element 6, and a voltage is generated between H and G. FIG. 6 shows a case where there is ink 3 on the surface of the correction roller 2, and the light emitted from the light emitting part 6a of the reflective photoelectric element 6 is reflected in the direction of arrow M2 on the ink surface, and the light emitted from the light emitting part 6a of the reflective photoelectric element 6 is Since the ink does not reach the light receiving portion 6b much, the voltage between H and G becomes a smaller value than when there is no ink 3 on the surface of the correction roller 2. FIG. 7 shows the voltage change between H and G in this example.
Section I is a voltage waveform when there is ink 3 on the surface of the correction roller 2, and section J is a voltage waveform when there is no ink 3 on the surface of the correction roller 2. Based on the difference in voltage between section I and section J, the discriminator 7 can easily and accurately determine the presence or absence of ink 3. Above, the central axis K- of the reflective photoelectric element 6 in the viewing direction
Although the case has been described in which K' and the slope n of the linear groove carved on the outer circumferential surface of the correction roller 2 are perpendicular, the central axis K- of the reflective photoelectric element 6 in the viewing direction is
To explain the case where K' and the slope n of the linear groove carved on the outer circumferential surface of the correction roller 2 are not perpendicular to each other, using FIG. Since detection can be performed with a certain angular width from If so, the reflected light can also be detected. Further, even when the ink 3 is almost completely removed from the surface of the correction roller 2, a small amount of ink 3 remains as shown in the groove P, and the reflection of the remaining ink 3 on the surface also causes the reflection type photoelectric element 6 to It can be detected by Further, the reflective photoelectric element 6 can also detect diffused reflection due to burrs, scratches, etc. that occur during the manufacturing of the correction roller 2, such as the groove Q portion. Therefore, the reflective photoelectric element 6 has its field of view center axis K.
-K' and the slope of the groove on the outer circumferential surface of the correction roller 2 are not necessarily perpendicular to each other and can be detected. but,
The visual field center axis K of the reflective photoelectric element shown in Fig. 8
If the angle L between -K' and the roller axis E-E' of the straightening roller 2 is less than 30°, it will be easily affected by ambient light, and if the angle L is between 60° and 90°, the straightening When there is ink 3 on the surface of roller 2,
Under the influence of light reflected on the surface of ink 3,
It has the same drawbacks as conventional detection methods. According to experiments, it has been confirmed that the presence or absence of ink 3 on the surface of the correction roller 2 can be detected stably and accurately when the angle L is in the range of 30° to 60°.

(Effect of the invention) As explained above, in the first embodiment, the reflection type photoelectric element corrects the direction of the central axis of the field of view of the reflection type photoelectric element at an angle of about 30 to 60 degrees with respect to the roller axis direction of the correction roller. Since it is placed facing the roller surface, if there is ink on the surface of the correction roller, even if the ink surface is irregularly undulated, it is hardly affected by it, and the light emitting part of the reflective photoelectric element The light emitted from the ink and reflected by the surface of the ink does not reach the light receiving section. Furthermore, when there is no ink on the surface of the correction roller, the light emitted from the light emitting part of the reflective photoelectric element is reflected by the grooves carved on the outer peripheral surface of the correction roller, and the reflected light reaches the light receiving part. This has the effect that the presence or absence of ink on the surface of the correction roller can be detected stably and accurately.
In addition, since the configuration is simple and a stable voltage can be obtained, sufficiently accurate results can be obtained even with a simple discriminator for determining the presence or absence of ink, and a highly reliable device can be obtained at a low cost.

In the first embodiment, a reflective photoelectric element having both a light emitting part and a light receiving part inside was used as the ink presence/absence detecting means, but as shown in FIG. , if the light emitting element 16a and the light receiving element 16b are arranged so that their field of view center axis K-K' forms an angle L of about 30° to 60° with respect to the roller axis E-E' of the correction roller 2. A similar effect occurs.

In the present invention, the reflective photoelectric element is arranged facing the surface of the straightening roller so that the center axis of the field of view of the reflective photoelectric element is at an angle of about 30° to 60° with respect to the roller axis of the straightening roller of the ink coating device. This has the advantage that the presence or absence of ink on the surface of the correction roller can be detected stably and accurately, and the structure is simple so that it can be used in an ink coating device of a printing machine or a thermal transfer recording device.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view showing an outline of an ink coating device having an ink presence/absence detecting means, and FIG. 2 is a side view showing the arrangement of a conventional reflective photoelectric element.
A′ cross-sectional view, Figure 3 is a wiring diagram, Figure 4 is a diagram showing the output voltage in the conventional example, and Figure 5 is the first diagram of the present invention.
FIG. 6 is a diagram showing the state with ink in the first embodiment of the present invention, and FIG. 7 is the output obtained in the first embodiment of the present invention. FIG. 8 is a diagram illustrating the angular range of the present invention, and FIG. 9 is a diagram illustrating another embodiment of the present invention. 1... Member to be coated, 2... Correction roller, 3...
Ink, 4... Backup roller, 5... Ink tank, 6... Reflective photoelectric element, 6a... Light emitting part in the reflective photoelectric element, 6b... Light receiving part in the reflective photoelectric element, 7... Discriminator, 8a and 8b...power supply, 9a and 9b...resistor, 16a...light emitting element, 16b...light receiving element.

Claims (1)

[Scope of utility model registration request] A member to be coated in the form of a film or a roller, a straightening roller whose outer circumferential surface has densely carved linear grooves and is pressed against the member to be coated, and an ink in liquid form attached to the straightening roller. In an ink coating apparatus equipped with an ink presence/absence detection means for detecting the presence or absence of ink, a reflective photoelectric element is used as the ink presence/absence detection means, and the center axis of the reflective photoelectric element in the viewing direction is approximately 30 mm from the roller axis direction of the correction roller. Opposing the surface of the straightening roller at an angle of ~60°,
The ink coating device characterized in that the reflective photoelectric element is arranged.