JPH10221905A - Transfer material discriminating device and image forming device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer material discriminating device capable of surely discriminating the kind of a transfer material regardless of the kind and the posture of the transfer material, and an image forming device provided with the same. SOLUTION: The light emitting part 4 of a transfer material detecting sensor 3 irradiates the transfer material 1 with light. The light is reflected by the transfer material, and made incident on a reflection mirror 5. The mirror 5 constituted of a corner cube, etc., reflects the light made incident from the transfer material in the same direction as the incident direction. As a result, the light passes through the same path as the one reaching the mirror 5 from the sensor 3, and returns to the sensor 3 from the mirror 5. A light receiving sensor 6 detects the returned light and outputs a signal in accordance with the quantity of the returned light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer material discriminating apparatus for discriminating the type of a transfer material such as printing paper, and an image forming apparatus having the same.

[0002]

2. Description of the Related Art At present, there are various transfer materials on which an image is formed in an image forming apparatus, such as plain paper, overhead projector sheet (hereinafter, referred to as "OHP sheet"), glossy paper, and the like. The optimum values for the above-described transfer and fixing conditions vary depending on the type of each transfer material. Therefore, the type of the transfer material is detected in advance, and conditions corresponding to each transfer material are set.

For detecting the type of transfer material, a transmission type transfer material sensor or a reflection type transfer material sensor is mainly used.

[0004]

The various transfer material detecting sensors described above have the following advantages and disadvantages.

[0005] 1. Transmission type transfer material detection sensor (Fig. 7
(See (a).) Light emitted from the light emitting unit 15 and transmitted through the transfer material 1 is received by the light receiving unit 16. Only the presence or absence of the transparency of the transfer material between the light receiving unit 16 and the light emitting unit 15 is detected. Therefore, O
The difference between a transmissive transfer material typified by an HP sheet and a non-transmissive transfer material typified by paper can be detected. However, the surface state of the transfer material such as glossiness cannot be detected.

[0006] 2. Reflective transfer material detection sensor (Fig. 7
(See (b).) The light emitted from the light emitting section 15 is obliquely incident on the transfer material 1. Then, the reflected light is received by the light receiving unit 16 that is directed perpendicular to the transfer material 1. The reflected light at this time is only the diffuse reflection component of the transfer material 1. Therefore, the surface state of the transfer material such as glossiness cannot be detected.

[0007] 3. Regular reflection type transfer material detection sensor (Fig. 7
(See (c).) The light emitted from the light emitting section 15 is obliquely incident on the transfer material 1. The light receiving unit 1 is located at the same angle and opposite to the light emitting unit 15 with respect to the normal line of the transfer material 1 corresponding to the regular reflection component direction.
At 6, the light reflected from the transfer material 1 is received. Since the reflected light at this time is a specular reflected light component, the surface of the transfer material such as glossy paper can be detected. However, the detection accuracy is not good because the position of the specularly reflected light changes due to slight inclination of the transfer material, displacement of the transfer material in the vertical direction, and the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a transfer material discriminating apparatus capable of accurately discriminating the type of a transfer material regardless of the type of the transfer material, and an image forming apparatus having the same.

[0009]

Means for Solving the Problems The present invention has been made to achieve the above-mentioned object, and a first aspect of the present invention is as follows. Reflecting means that reflects light and emits light in the same direction as the angle of incidence, and outputs a signal corresponding to the light incident from the transfer material, a light receiving unit installed in proximity to the light emitting unit,
A determination unit that outputs a signal corresponding to a detection result of the light receiving unit.

The reflecting means may include a corner cube having three mirror surfaces perpendicular to each other.

It is preferable that the signal output from the determination means is a signal indicating the type of the transfer material.

The discrimination means has discrimination information in which the detection result of the light receiving section is associated with the type of the transfer material, and the discrimination information is referred to based on the detection result to determine the type of the transfer material. May be output.

[0013] A plurality of sets of the light emitting section and the light receiving section may be provided. In this case, it is preferable that the respective pairs of the light emitting unit and the light receiving unit have different angles with respect to the transfer material.

It is preferable that the light emitting section and the light receiving section are integrated.

According to a second aspect of the present invention, there is provided an accommodating portion for accommodating a transfer material, a transfer material discriminating apparatus for judging the type of the transfer material, and a transfer device accommodated in the accommodating portion. An image forming apparatus is provided, comprising: a sheet feeding / conveying unit that feeds and conveys a sheet; and an image forming unit that forms an image on a transfer material fed and conveyed by the sheet feeding / conveying unit. You.

It is preferable that the sheet feeding / conveying means changes the sheet feeding / conveying condition in accordance with a result of the judgment by the transfer material judging device.

The sheet feeding and conveying means includes a roller configured to change a contact pressure on the transfer material, and the condition includes a contact pressure of the roller on the transfer material. May be included.

The operation will be described.

The light emitting section irradiates the transfer material with light. Then, this light is reflected by the transfer material and enters the reflection means. Reflecting means (for example, a corner cube having three mirror surfaces perpendicular to each other) reflects light incident from the transfer material and emits the light in the same direction as the angle of incidence. As a result, the light emitted from the reflection means returns along the same path. Then, the light enters a light receiving unit provided near the light emitting unit. The light receiving unit detects the intensity of light incident from the transfer material.

The determining means outputs a signal corresponding to the detection result of the light receiving section. For example, a signal indicating the type of the transfer material may be output by referring to the determination information.

Incidentally, depending on the type of the transfer material and the angle of the light emitted by the light emitting section, the type of the transfer material may not be sufficiently discriminated in some cases. Therefore, in order to cope with this, a plurality of sets of light emitting units and light receiving units having different installation angles may be provided. In this way, it is possible to cope with various transfer materials more reliably.

If the conditions for feeding and feeding (for example, the contact pressure of the rollers with the transfer material) by the feeding and feeding means are adjusted according to the type of transfer material detected in this way, the feeding is stabilized.

[0023]

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

[First Embodiment] A first embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. FIG.

FIG. 1 shows a part of a storage portion of the transfer material 1.

This embodiment is a transfer material discriminating apparatus for discriminating the type of transfer material.

The transfer material discriminating apparatus includes a transfer material detection sensor 3, a reflecting mirror 5, and a sensor controller 7.

The transfer material detecting sensor 3 is provided above the cassette 2 and includes a light emitting unit 4 and a light receiving unit 6. The light emitting section 4 irradiates the transfer material 1 stored in the cassette 2 with light at a predetermined angle with respect to the normal line of the transfer material 1. The light emitting section 4 includes a light emitting element, a lens, and the like.

The light receiving section 6 generates an output current according to the amount of received light. The light receiving section 6 includes a light receiving element, a lens, and the like. The light receiving section 6 is installed close to the light emitting section 4. In particular, in the present embodiment, the light receiving section 6 is integrated with the light emitting section 4.

The sensor controller 7 controls the transfer material detecting sensor 3. Specifically, the sensor controller 7 has a function of causing the light emitting section 4 to emit light in accordance with a transfer material type determination command signal 14 input from a main controller of the image forming apparatus having the transfer material determination device. Further, a function is provided for determining the type of the transfer material based on the output current of the light receiving unit 6 at this time, and outputting the determination result as a transfer material type determination signal 8 to the main controller.

The sensor controller 7 is, specifically,
It is composed of electronic circuits such as memories and ICs. This memory stores data (determination information) indicating the relationship between the output current value of the light receiving unit 6 and the type of transfer material, which is measured in advance.
Is stored. The sensor controller 7 determines the type of the transfer material by referring to the data.

The reflecting mirror 5 reflects the light incident from the transfer material in the same direction as the incident light. In the present embodiment, a corner cube is employed as the reflecting mirror 5, and this is set in the direction of the specular reflection component of the transfer material 1, that is,
Are arranged at the same angle in the direction opposite to the light emitting unit 4 with respect to the normal line. The incident path of the incident light from the transfer material varies according to the state (position, angle, etc.) of the transfer material. Therefore, the reflecting mirror 5 is sized so as to be able to capture the reflected light in any state of the transfer material, assuming the possible state (position, posture) of the transfer material in advance.

The reflecting mirror 5 (corner cube) in this embodiment will be described in detail with reference to FIG.

As described above, the reflecting mirror 5 in the present embodiment is a corner cube composed of three mirrors perpendicular to each other (see FIG. 2A). Reflect in the same direction. In some cases, one set of these three mirrors is uniformly arranged on a plane.

FIG. 2B is a view of the case where a large number of reflecting mirrors 5 are arranged on a plane, as viewed from the light incident direction. FIG. 2C shows an optical path viewed from the z-axis direction (a direction perpendicular to the paper surface) of FIG. 2A.

Light incident at an angle θ with respect to the x-axis is reflected by the incident mirror surface. The reflected light is incident at an angle (90-θ) with respect to the y-axis. Then, the light is finally reflected at an angle (90-θ) with respect to the y-axis. Note that, in the z-axis direction, since there is a mirror parallel to the paper surface, even if the light is reflected by this mirror, the trajectory of light on the xy axis in FIG. 2 does not change. That is, the light incident on the reflecting mirror 5 is always reflected in the same direction as the incident direction.

In this embodiment, the reflecting mirror 5 corresponds to the "reflecting means" in the present invention. In the present embodiment, the sensor controller 7 corresponds to the “determination unit”.

Next, the operation of determining the transfer material in the transfer material determining apparatus will be described.

The main controller of the image forming apparatus outputs a transfer material type determination command signal 14 before starting the development.

The sensor controller 7 that has received the transfer material type determination command signal 14 causes the light emitting section 4 to emit light. The light irradiates the transfer material 1 in the cassette 2. Then, the specularly reflected light enters the reflecting mirror 5. The reflecting mirror 5 reflects the incident light in the same direction as the incident light. as a result,
The light emitted from the reflecting mirror 5 follows the same path in reverse, is reflected again on the transfer material 1, and finally enters the light receiving section 6.

The light receiving section 6 outputs an output current having a magnitude corresponding to the amount of received light. The sensor controller 7 determines the type of the transfer material by referring to the determination information based on the output current. Then, a transfer material type determination signal 8 corresponding to the determination result is output. As described above, in the present embodiment, since the reflected light always returns to the transfer material detection sensor 3, the transfer material can be detected and determined without being affected by the state of the transfer material 1 (for example, rising or tilting from the reference surface). This will be described in more detail with reference to FIG.

FIG. 3A shows the transfer material detecting sensor 3 and the transfer material 1 when the transfer material 1 is fully loaded in the cassette.
And the relationship between the optical path and the light path. FIG. 3B shows the relationship between the sensor, the transfer material, and the optical path when the transfer material 1 is small.

The cassette 2 has the following configuration. The middle plate 10 in the cassette 2 is configured to be rotatable around a fulcrum 13 within a range between the bottom plate of the cassette 2 and the separation claw 12. Then, a constant force is applied to the middle plate 10 upward by the spring 11. The transfer material 1 is stacked on the middle plate 10.

In FIG. 3, the angle between the transfer material 1 and the cassette 2 when the transfer material is fully loaded is θa, and the angle when the transfer material is small is θb. The angle difference (θa−θb) of the transfer material surface is about 13 between a state where the transfer material is fully loaded (for example, a state where about 50 mm of A4 size transfer material is stacked) and a small load state. ° reach. Even if the angle of the transfer material surface changes in this way, the reflected light always returns to the transfer material detection sensor 3 as long as the light is incident on the reflecting mirror 5.

As described above, in the first embodiment, the type of the transfer material can be reliably detected without being affected by the displacement of the transfer material. Therefore, the transfer material detection sensor 3 and the reflecting mirror 5 can be installed in a place other than the cassette 2 (for example, a transfer material transport path).

The positional relationship between the reflecting mirror 5 and the transfer material detecting sensor 3 is not limited to the above-described relationship (the same angle in the direction opposite to the light emitting section 4 with respect to the normal line of the transfer material 1).
Any other positional relationship may be used as long as the light from the transfer material enters the reflecting mirror 5.

Further, the reflecting mirror 5, the transfer material detecting sensor 3
Even if the mounting angle is slightly shifted, there is no effect on the detection and determination of the transfer material. Therefore, the design, design, and the like of the transfer material discriminating device and various devices incorporating the transfer material discriminating device are further improved.
Assembly becomes easy. Such a point leads to a reduction in apparatus cost.

The sensor controller 7 of the present embodiment determines the type of the transfer material by referring to the determination information prepared in advance. However, the specific determination method is not limited to this. A signal corresponding to the transfer material type determination signal 8 may be obtained by performing a predetermined operation on the output signal of the light receiving unit 6.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIGS.

The same functional portions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The basic structure of the second embodiment is the same as that of the first embodiment. However, in the second embodiment, as shown in FIG. 4, a plurality of transfer material detection sensors 3 having different installation angles with respect to the normal direction of the transfer material are provided.

Data indicating the relationship between the output current value of the light receiving section 6 and the type of transfer material, which is provided in advance in the sensor controller 7, is prepared for each transfer material detection sensor 3.

FIG. 5 shows the results of measuring the relationship between the light emitting / receiving angle and the light receiving amount for various transfer materials. As can be seen from FIG. 5, the amount of light received by the light receiving sensor 6 varies depending on the transfer material and the light emitting / receiving angle. If the angle is too large (75 ° in the example of FIG. 5), it is difficult to distinguish glossy paper from OHP sheets. Although it is not clear in FIG. 5, if the angle is too small, it is difficult to distinguish between plain paper and glossy paper. In the present embodiment, by installing a plurality of transfer material detection sensors 3 having different angles with respect to the normal direction of the transfer material,
It is possible to detect all kinds of transfer materials with the optimum amount of received light.

In the first embodiment described above, since the transfer material surface is reflected twice, the light may be very weak before reaching the light receiving sensor 6. In particular, when the surface glossiness of the transfer material is low, it is conceivable that the strength is reduced to such an extent that it cannot be detected. However, in the second embodiment, since a plurality of transfer material type detection sensors 3 having different installation angles are provided, a range (a type and a posture of the transfer material) in which an optimum light receiving amount can be obtained is wide. That is, in the second embodiment, it is possible to more reliably detect and determine the transfer material.

[Third Embodiment] The third embodiment is characterized in that:
An electrophotographic full-color laser beam printer including the transfer material discriminating apparatus described in the first and second embodiments will be described with reference to FIG.

The control device 100 previously determines the type of the transfer material 1 stored in the cassette 2 by the transfer material determination device 110. The transfer material discriminating device 110
Is as described in the first and second embodiments.

The transfer material 1 in the storage cassette 2 is taken out one by one by the paper feed roller 9 and supplied to the transfer drum 17. The timing at which the transfer material 1 reaches the transfer drum 17 is adjusted by the registration rollers 23.
In this case, the control device 100 adjusts the contact pressure of the paper feed roller 9 and the like according to the detection result (the transfer material type determination signal 8) of the transfer material determination device 110, that is, the type of the transfer material. Therefore, the transfer of the transfer material is more stable.

On the other hand, the scanner 13 irradiates the photosensitive drum 21 with laser light whose intensity has been modulated according to the image information signal sent from the host computer. Thus, an electrostatic latent image corresponding to the image information is formed on the photosensitive drum 21.

The portion of the electrostatic latent image irradiated with the laser beam is selectively visualized by an electric field formed by the voltage applied to the developing sleeve 22 and the surface potential of the photosensitive drum 21.

In the case of full color, the same processing is usually repeated for four colors of yellow, magenta, cyan, and black. The density of the image is substantially determined by the electric field strength, the characteristics of the toner, and the amount of toner on the developing sleeve.

Then, the transfer material 1 is brought into close contact with the transfer drum 17, and the toner image on the photosensitive drum 21 is sequentially transferred to the transfer material 1 for each color.

Thereafter, the transfer material 1 is passed through a fixing roller 18 and the toner image is fixed thereon to form a permanent fixed image. Thereafter, the transfer material 1 is stacked on the tray 20 by the paper discharge roller 19.

In the laser beam color printer of the third embodiment, more reliable transport can be realized by adjusting the transport conditions of the transfer material according to the type of the transfer material.

The present invention is applicable not only to an image forming apparatus but also to any apparatus that handles sheet materials.

[0065]

As described above, according to the present invention, the transfer material can be reliably detected and determined irrespective of the state (position, posture, lifting) of the transfer material at the time of detecting the transfer material. Further, in an image forming apparatus provided with this, the transfer of the transfer material and the like can be more reliably performed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a transfer material discriminating apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the principle of reflection by a reflecting mirror 5;

FIG. 3 is a diagram illustrating a correspondence to a difference in posture of a transfer material.

FIG. 4 is a diagram illustrating a configuration of a transfer material determining device according to a second embodiment of the present invention.

FIG. 5 is a graph showing a relationship between a light emitting / receiving angle and a light receiving amount for various transfer materials.

FIG. 6 is a diagram illustrating an image forming apparatus according to a third embodiment of the present invention.

7A and 7B are diagrams illustrating a detection principle of a conventional transfer material detection sensor, wherein FIG. 7A is a transmission type transfer material detection sensor, FIG. 7B is a reflection type transfer material detection sensor, and FIG. 7C is a specular reflection type transfer material. 4 shows a detection principle of a detection sensor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transfer material 3 transfer material detection sensor 4 light emitting unit 5 reflecting mirror 6 light receiving unit 7 sensor controller 9 paper feed roller

Claims (10)

[Claims] A light emitting unit that irradiates light to the transfer material; a reflecting unit that reflects light incident from the transfer material and emits the light in the same direction as the angle of incidence; A transfer material discriminating apparatus, comprising: a light receiving unit installed in proximity to the light emitting unit, for outputting a signal, and a discriminating unit for outputting a signal according to a detection result of the light receiving unit. 2. The transfer material discriminating apparatus according to claim 1, wherein said reflecting means includes a corner cube having three mirror surfaces perpendicular to each other. 3. The transfer material discriminating apparatus according to claim 1, wherein the signal output from the discriminating means is a signal indicating a type of the transfer material. 4. The transfer medium according to claim 1, wherein the determination unit has determination information in which a detection result of the light receiving unit is associated with a type of the transfer material, and the determination unit refers to the determination information based on the detection result. 4. The transfer material discriminating apparatus according to claim 1, wherein the transfer material discriminator outputs a signal indicating the type of the transfer material. 5. The transfer material discriminating apparatus according to claim 1, wherein a plurality of sets of the light emitting unit and the light receiving unit are provided. 6. The transfer material discriminating apparatus according to claim 5, wherein each set of the light emitting unit and the light receiving unit has a different angle with respect to the transfer material. 7. The transfer material discriminating apparatus according to claim 1, wherein the light emitting unit and the light receiving unit are integrated. 8. A storage section for storing a transfer material, and a type of the transfer material is determined.
A transfer material discriminating apparatus according to claim 5, 6, or 7, a paper feeder for feeding and transporting the transfer material stored in the storage section, and an image on the transfer material fed and transported by the paper feeder. An image forming apparatus, comprising: 9. The image forming apparatus according to claim 8, wherein the paper feeder changes the paper feed condition in accordance with a result of the determination by the transfer material determiner. . 10. The paper feeding / conveying means is configured to include a roller configured to change a contact pressure on the transfer material, and the condition is that the roller transfers the contact pressure to the transfer material. The image forming apparatus according to claim 9, wherein a contact pressure is included.