JP6594384B2 - Detection apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a detection apparatus and an image forming apparatus for irradiating light to a detection material and detecting reflected light from the detection material.

In recent years, there has been an increasing need for higher image quality and ecology in image forming apparatuses such as copying machines, laser beam printers, and ink jet printers.
Conventionally, in a scene where high image quality is required, a reference pattern patch image (detected material) formed on a recording material is detected by a detection device arranged in the image forming apparatus. Then, correction data is created by comparing the output data with the data of the reference pattern, and the image quality such as the color of the image to be formed next is calibrated.
On the other hand, in order to cope with ecology, the detection device detects the surface texture image of the recording material (recording medium) and discriminates the type of the recording material, so that the image forming conditions can be set according to the type of the recording material. Change to print with minimum energy.
In order to read the patch image on the recording material and the image of the surface property of the recording material, it is desirable that the detection device used in these technologies is arranged in a conveyance path through which the recording material is conveyed during image formation.
However, if the detection device is disposed in the conveyance path, the detection device is contaminated by paper dust or the like, and there is a possibility that the patch image or surface property on the recording material cannot be detected accurately.

In order to solve such a problem, a configuration is known in which a shutter (opening / closing member) that opens and closes an opening of a detection device is arranged (see Patent Document 1). The imaging unit includes an illumination light source (light emitting element) that emits light to a reference chart (detected material) through an opening, and a sensor (light receiving element) that receives reflected light from the reference chart. Contamination due to paper dust or the like is minimized by opening the shutter at the time of imaging and closing the shutter at the time of normal recording material conveyance without imaging.
In order to increase the reading accuracy by the detection device, it is desirable to control the distance between the light receiving element and the recording material to be constant. In order to make the distance constant, the detection device can be brought into close contact with the recording material at the time of detection.Therefore, a method is considered in which the detection device is brought into contact with the opposite surface of the conveyance path facing the detection device and the recording material is sandwiched between them. It is done.
However, if the detection device is constantly abutted against the opposite surface of the conveyance path, there is a concern about image defects due to friction or the like, or a paper jam of a recording material that is weak. Therefore, it is desirable to bring the detection device into contact with the opposite surface of the conveyance path during reading, and to separate the detection device from the opposite surface during non-reading.
As a technique for realizing such a contact / separation operation of the detection device, for example, Patent Document 2 discloses a first method in which a color measurement unit (detection device) including a color measurement sensor (light receiving element) presses a recording material . The structure which moves between a position and the 2nd position which cancels | releases a press is proposed.

JP 2013-205258 A JP 2013-148503 A

However, as in Patent Document 1, in order to detect and control the opening and closing of the shutter, a detecting means such as a sensor for detecting the opening and closing state of the shutter is required separately.
In addition, as in Patent Document 2, in order to realize an operation of moving the color measurement unit (the apparatus main body of the detection device) to a first position where the recording material is pressed and a second position where the pressure is released. In addition, a detection means for detecting the position of the color measurement unit is required.
Accordingly, inventions of interest that put in this application to provide a sensing device and an image forming apparatus and without adding new detection means for detecting the opening and closing of the closing member, can detect the opening and closing of the opening and closing member is there.
Or, without adding a new detection means for detecting the position of the apparatus body with a light-emitting element and a light receiving element is to provide a sensing device and an image forming apparatus and can detect the position of the apparatus main body .

In order to achieve the above object, the detection device of the present invention comprises:
A light emitting element that emits light to the material to be detected;
A light receiving element that receives reflected light from the material to be detected;
An apparatus body having an opening / closing member that opens and closes an opening through which light emitted from the light emitting element and reflected light from the detected material pass, and control for controlling movement of the apparatus body and opening / closing of the opening / closing member And
The opening and closing member is opened in response to the movement of the apparatus main body to a first position where the apparatus main body abuts on the detected material, and the apparatus main body moves to a second position separated from the detected material. In the detection device that closes the opening and closing member according to
The light receiving element outputs a first output when the opening and closing member is open, and outputs a second output different from the first output when the opening and closing member is closed,
The control unit receives the reflected light from the detected material a plurality of times by the light receiving element during the opening / closing operation of the opening / closing member, and the light receiving element outputs the first output in advance during the period. the duration of the part which defines and judged when the closing member is open, the closing member advance period portion which defines within a period in which the light receiving element is outputting the second output is closed characterized in that it judged if it has.
In order to achieve the above object, the detection device of the present invention, a light emitting element for emitting light to the detected member, a light receiving element for receiving reflected light from the detection target material, the light emitting from the light emitting element And an opening and closing member that opens and closes an opening through which reflected light from the detected material passes, and an apparatus main body,
A control unit for controlling movement of the apparatus main body and opening / closing of the opening / closing member;
The opening and closing member is opened in response to the movement of the apparatus main body to a first position where the apparatus main body abuts on the detected material, and the apparatus main body moves to a second position separated from the detected material. In the detection device that closes the opening and closing member according to
The light receiving element, when the closing member is open, outputs the first output, the if the closing member is closed and outputs a different second output and said first output,
The control unit receives the reflected light from the detected material a plurality of times by the light receiving element during the opening / closing operation of the opening / closing member, and the light receiving element outputs the first output in advance during the period. the apparatus main body period portion which defines is judged to be in the first position, the device in advance period portion which defines within a period in which the light receiving element is outputting the second output body, characterized in that judged to be in the second position.
Further, the image forming apparatus of the present invention is characterized in that the above-described detection device is disposed to face a conveyance path of a recording medium as a detected material.

According to the detection device of the present invention , it is possible to control the opening / closing of the opening / closing member without newly adding a detecting means for detecting the opening / closing member, thereby reducing the cost.
Furthermore, without adding a detection means for detecting the position of the apparatus body with a newly-emitting element and a light receiving element, it is possible to contact and separation control of the apparatus main body, cost reduction can be achieved.
Further, according to the image forming apparatus of the present invention, the opening / closing control of the shutter and the contact / separation position of the color measurement device can be performed without adding a detection unit for detecting opening / closing of the opening / closing member and a detection unit for detecting the position of the apparatus main body. An image forming apparatus capable of performing the above control can be realized.

FIG. 3 is a schematic perspective view illustrating an operation mechanism of the color measurement unit according to the first embodiment. 1 is a schematic cross-sectional view of an image forming apparatus to which the present invention is applied. FIG. 3 is a schematic diagram of a toner patch image formed on a recording material. FIG. 2 is an enlarged cross-sectional view of the color measuring device in FIG. 1 and a schematic diagram of an internal configuration of the color measuring device. Schematic showing the relationship between the cam gear of FIG. 1 and a slide cam. Schematic showing the relationship between the slide cam of FIG. 1 and a color measurement unit. Schematic showing the relationship between the cam gear of FIG. 1, a slide cam, and a shutter. The figure which shows the relationship of the phase of the cam gear of FIG. 1, the position of a color measurement unit, and a shutter opening degree. The figure which showed the relationship between the phase of the cam gear of FIG. 1, and the load torque of a motor. The figure which showed the relationship of the output of the colorimeter of FIG. The block diagram of the motor control of FIG. 3 is a flowchart for determining a contact / separation position of the color measurement unit in FIG. 1. FIG. 6 is an enlarged cross-sectional view of a color measuring device according to Embodiment 2 of the present invention. The expanded sectional view of the color measurement apparatus which concerns on other embodiment of this invention.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.
In the following description, an image forming apparatus equipped with a color measurement device as a detection device according to the present invention will be described as an example. As an image forming apparatus, an electrophotographic color laser printer (hereinafter referred to as LBP) is exemplified. The color measuring device is intended to realize a stable color of the output image, detects the color of the output image using the color measuring device, and feeds back the process condition of the image forming apparatus. It is a device. The detection device of the present invention is not limited to a colorimetric device, but can also be used for a so-called media sensor or the like that photographs the surface properties of a recording material (recording medium) and discriminates the type of the recording material. Furthermore, although the present invention is applied to the LBP as an image forming apparatus, the present invention is not limited to this and can also be applied to a copying machine, an ink jet printer, or the like.

(Configuration of image forming apparatus)
First, a schematic configuration of an LBP as an image forming apparatus to which the present invention is applied will be described with reference to FIG. FIG. 2 is a schematic cross-sectional configuration of an LBP to which the present invention is applied.
First, the image forming unit will be described.
The image forming unit includes photoreceptors (hereinafter referred to as photosensitive drums) 31Y, 31M, 31C, and 31K for each color YMCK station. Around the photosensitive drums 31Y, 31M, 31C, 31K, charging rollers 32Y, 32M, 32C, 32K as primary charging means, exposure scanner units 33Y, 33M, 33C, 33K, developing devices 38Y, 38M as developing means, 38C and 38K are provided.
The photosensitive drums 31Y, 31M, 31C, and 31K are configured by applying an organic photoconductive layer to the outer periphery of an aluminum cylinder, and rotate by receiving a driving force of a driving motor (not shown). The drive motor rotates the photosensitive drums 31Y, 31M, 31C, and 31K in the clockwise direction according to the image forming operation.
The photosensitive drums 31Y, 31M, 31C, 31K, the charging rollers 32Y, 32M, 32C, 32K, and the developing units 38Y, 38M, 38C, 38K are integrated. In addition, toner cartridges 39Y, 39M, 39C, and 39K that are detachable from the image forming apparatus main body are configured.

The photosensitive drums 31Y, 31M, 31C, and 31K are arranged in a horizontal row along the intermediate transfer belt 37. The intermediate transfer belt 37 has primary transfer rollers corresponding to the photosensitive drums 31Y, 31M, 31C, and 31K. 34Y, 34M, 34C, and 34K are provided. The intermediate transfer belt is an endless belt that is wound around the driving roller 41 and the stretching roller 40, and tension is applied by the auxiliary roller 42. Further, the secondary transfer roller 43 is in contact with the winding portion of the intermediate transfer belt 37 around the drive roller 41 to form a secondary transfer portion.
Below the intermediate transfer belt 37, a paper feed cassette 44 for storing a recording material P as a recording medium is disposed. Further, a sheet feeding conveyance path for conveying the recording material P in the sheet feeding cassette 44 toward the secondary transfer portion which is a contact portion between the secondary transfer roller 43 and the intermediate transfer belt 37 by the sheet feeding rollers 45 and 46. A is provided. Further, a fixing unit 51 is disposed above the secondary transfer unit, and above the fixing unit 51, the recording material P discharged from the fixing unit 51 is placed on a discharge tray 52 on the upper surface of the apparatus by a discharge roller 50. A paper discharge conveyance path B for paper discharge is provided. In the present embodiment, a double-sided conveyance path D that bypasses the fixing unit 51 from the paper discharge conveyance path B and returns to the paper supply conveyance path is provided from the paper discharge conveyance path B.
Reference numeral 55 denotes a main body control unit, and reference numeral 56 denotes an image formation control unit, which controls the above-described components.

Next, the operation of LBP will be described.
When the main body controller 55 receives the image signal, the recording material P is sent out from the paper feed cassette 44 by the paper feed rollers 45 and 46. Then, it is once held between a roller-like synchronous rotating body for synchronizing an image forming operation described later and conveyance of the recording material P, that is, a conveyance roller pair (registration roller pair) 47, and then stops and waits.
On the other hand, the image forming control unit 56 drives the exposure scanner units 33Y, 33M, 33C, and 33K according to the received image signal. The surfaces of the photosensitive drums 31Y, 31M, 31C, and 31K that are uniformly charged by the charging rollers 32Y, 32M, 32C, and 32K are exposed and scanned to form electrostatic latent images.
Developing units 38Y, 38M, 38C, and 38K are means for visualizing the electrostatic latent image, and develop yellow (Y), magenta (M), cyan (C), and black (K) for each station. Each developing device 38Y, 38M, 38C, 38K is provided with a sleeve 35Y, 35M, 35C, 35K, and a developing bias for visualizing the electrostatic latent image is applied. In this manner, the electrostatic latent images formed on the surfaces of the photosensitive drums 31Y, 31M, 31C, and 31K are developed as single color toner images by the action of the developing units 38Y, 38M, 38C, and 38K.
The intermediate transfer belt 37 is in contact with the photosensitive drums 31Y, 31M, 31C, and 31K, and rotates counterclockwise in synchronization with the rotation of the photosensitive drums 31Y, 31M, 31C, and 31K when forming a color image. The developed single color toner image is sequentially transferred by the action of the primary transfer bias applied to the primary transfer roller 34, and becomes a multicolor toner image on the intermediate transfer belt 37.

Thereafter, the multicolor toner image formed on the intermediate transfer belt 37 is conveyed to a secondary transfer nip portion formed by the drive roller 41 and the secondary transfer roller 43. At the same time, the recording material P that has been waiting while being held between the conveying roller pair 47 is synchronized with the multi-color toner image on the intermediate transfer belt 37 by the action of the conveying roller pair 47 and enters the secondary transfer nip portion. Be transported. The multicolor toner images on the intermediate transfer belt 37 are collectively transferred by the action of the secondary transfer bias applied to the secondary transfer roller 43.
The fixing unit 51 melts and fixes the transferred multi-color toner image while transporting the recording material P. The fixing unit 51 presses the recording material P against the fixing roller 51a. A pressure roller 51b is provided. The fixing roller 51a and the pressure roller 51b are formed in a hollow shape, and a heater 51ah is built in the fixing roller.
The recording material P holding the multicolor toner image is conveyed by the fixing roller 51a and the pressure roller 51b, and heat and pressure are applied to fix the toner on the surface of the recording material.
The recording material P after the toner image is fixed is discharged to a discharge tray 52 by a discharge roller 50 and the image forming operation is completed. Alternatively, when image formation is performed on the second side, the switchback operation in the paper discharge conveyance path B returns to the paper feed conveyance path A via the double-side conveyance path D, and again the conveyance roller pair 47 ( It is once held between the registration roller pair) and stops and waits. Thereafter, the series of image forming operations described above is performed, and image formation is performed on the second surface of the recording material P. The double-sided conveyance path D extends obliquely downward so as to bypass the fixing unit 51 from the paper discharge conveyance path B, then extends vertically downward, and further changes its direction to a U shape so as to join the paper conveyance path A. Configured to do. In the double-sided conveyance path D, a first conveyance roller pair 61, a second conveyance roller pair 62, and a third conveyance roller pair 63 are sequentially arranged at a predetermined interval from the discharge conveyance path B side downward.
The cleaning unit 48 cleans the toner remaining as the transfer residual toner on the intermediate transfer belt 37, and the transfer residual toner collected here is stored in the cleaner container 49 as waste toner.

Next, the color measurement of the toner patch by the color measurement device 100 constituting the detection device of the present invention will be described .
As shown in FIG. 2, the colorimetric device 100 is provided in a region extending vertically in the double-sided conveyance path D, in the illustrated example, between the second conveyance roller pair 62 and the third conveyance roller pair 63. The color measuring device 100 includes a color measuring unit 10 as a device main body that measures the color of an image on a recording material P and outputs it as electronic data.
When the color measurement mode of the toner patch T is started, first, the toner patch T which is a patch image for image quality calibration as shown in FIG. 3 is formed on the recording material P by the series of operations described above. . In the toner patch T, images of a plurality of basic patterns having different densities for each color are formed in a line along the transport direction at the center in the width direction perpendicular to the transport direction of the recording material P.
The recording material P that has passed through the fixing unit 51 is transferred to the double-sided conveyance path D by a switchback operation in the paper discharge conveyance path B, and the toner patch T formed on the recording material P is recorded by the colorimetric unit 10. The color is sequentially measured in synchronization with the conveyance of the material P. In order to measure the color of the toner patch T formed in the center in the width direction of the recording material P, the color measurement unit 10 is in a direction orthogonal to the conveyance direction Y (vertically downward in the illustrated example) of the double-sided conveyance path D, that is, the second. The third conveying roller pair 62 and 63 are disposed opposite to each other at the center in the longitudinal direction.
The recording material P colorimetrically measured by the color measurement unit 10 and passed through the double-sided conveyance path D makes a U-turn at the lower end of the double-sided conveyance path D, returns to the paper feed conveyance path A, and passes through the secondary transfer unit / fixing unit 51. Then, the paper is discharged to the paper discharge tray 52 by the paper discharge roller 50.
Such a series of image forming operations and toner patch colorimetric operations are controlled by the main body control unit 55, and the colorimetric data of the toner patches T measured by the colorimetry unit 10 are sent to the main body control unit 55. It is done. The main body control unit 55 creates color correction data based on the colorimetric data and feeds it back to image information of an image to be formed next.

[Embodiment 1]
Next, the color measuring device (detecting device) 100 according to the first embodiment of the present invention will be described in detail with reference to FIGS. 1 and 4 to 7.
(About color measuring unit)
First, a schematic configuration of the color measurement unit 10 constituting the color measurement device 100 will be described with reference to FIG. 4A shows a separated state in which the color measurement unit 10 is separated from the conveyance surface Da guiding the recording material P, and FIG. 4B shows a contact state in which the color measurement unit 10 abuts on the conveyance surface Da. Yes. FIG. 4C is a schematic view of the internal configuration of the color measurement unit 10 of FIG. 4B as viewed from the Y direction.
The color measurement unit 10 is disposed facing the double-sided conveyance path D, and can advance and retreat in a direction orthogonal to the conveyance surface Da of the opposite double-sided conveyance path D. In the following description, the contact direction in contact with the transport surface Da is X, and the transport direction of the recording material P is Y. Moreover, about each structural member, the surface by the side of the conveyance surface Da is demonstrated as a front surface, and the opposite side to the conveyance surface Da is demonstrated as a back surface.
The color measuring unit 10 opens and closes a color measuring device 11 as a detection unit that measures the toner patch of the recording material P passing through the double-sided conveyance path D and a color measuring window 11 a that is an opening of the color measuring device 11. And a shutter 14 as a member. Further, a colorimeter base 13 for fixing the colorimeter 11 and a colorimeter cover 12 as a cover member that covers the colorimeter 11 and the shutter 14 are provided. The colorimetric window 11a is protected so that dust, paper powder, and the like do not enter the colorimeter 11 by closing the opening surface with, for example, glass or a cover sheet. The shutter 14 is a member for preventing the opening surface made of glass, a cover sheet, or the like of the colorimetric window 11a from being stained by dust or paper powder.
The colorimeter 11 includes a light source (light emitting element) 111 such as an LED that irradiates light on the toner patch of the recording material P, and a light receiving element 112 such as a line sensor that receives reflected light from the toner patch. Yes. The irradiation window 11 a is a portion through which light emitted from the light source 111 and reflected light from the recording material P pass, and is opened and closed by the shutter 14.
As shown in FIG. 4C, the internal configuration of the colorimeter 11 has a diffraction grating 115 that splits diffusely reflected light from the recording material P, and receives light dispersed by the diffraction grating 115 as a light receiving element 112. Is configured to receive light. In the recording material reflection optical path from the light source 111, a light guide member 113 having a lens for condensing the irradiation light from the light source 111 on the recording material, and in the optical path from the recording material to the diffraction grating 115, A light guide member 114 having a lens for condensing the reflected light on the diffraction grating 115 and a slit 116 are disposed. However, the internal configuration of the colorimeter 11 is not limited to the configuration shown in the drawing, and any configuration having spectroscopic means such as the diffraction grating 115 and the prism in the illustrated example may be used. The arrangement of the light source 111, the light receiving element 112, and the diffraction grating 115 and the configuration of the optical path can take various configurations depending on the arrangement space, the position of the colorimetric window 11a, and the like.
The colorimeter base 13 is a plate-like member that is fixed to the back surface of the colorimeter 11, and is provided in parallel to the transport surface Da. An L-shaped engagement piece 130 having an abutting portion 13 a that engages with the slide cam 15 as shown in FIG. 1 is provided on the back surface of the colorimeter base 13. The engaging piece 130 has a base portion 13b extending from the back surface of the colorimeter base 13 in the direction opposite to the contact direction X, and a bent portion 13c bent from the tip of the base portion 13b in parallel with the transport direction Y. A contact portion 13a protrudes from 13c. The slide cam will be described later.
The colorimeter cover 12 has an open box cross-sectional shape that is open on the colorimeter base 13 side, and an end portion is fixed to the colorimeter base 13 to constitute a housing together with the colorimeter cover 12. And the front surface 12b which opposes the double-sided conveyance path D is a plane parallel to the conveyance surface Da of the opposing double-sided conveyance path D. An opening 12 a is also provided on the front surface 12 b of the colorimeter cover 12. The opening 12a is not blocked by glass, a cover sheet, or the like like the irradiation window 11a. This opening 12a is in contact with member to the conveying surface Da, if there is a glass and a cover sheet, etc., or attached Therefore scratched contact the recording material P at the time of detection, or adhering dust and paper dust This is to prevent the detection accuracy from deteriorating. However, if the opening 12a is hollow, dust and paper powder will pass through the opening 12a, so that the shutter 14 covers the opening surface of the colorimetric window 11a so as not to get dirty.

In the color measurement unit 10, the position where the front surface 12b of the colorimeter cover 12 facing the double-sided conveyance path D is in contact with the conveyance surface Da is a contact position (first position) (see FIG. 4B). A position separated from the conveyance surface Da is a separation position (second position) (FIG. 4A).
In the color measurement unit 10, the color measurement unit 10 is urged in the contact direction X with respect to the transport surface Da by the urging member 18. The biasing member 18 is disposed so as to press the back surface of the color measurement unit 10. That is, the urging member 18 is in a compressed state, and one end thereof is engaged with the back surface of the colorimeter base 13 and the other end is engaged with a main body frame (not shown).
At the separation position, the gap between the front surface 12b of the colorimeter cover 12 and the conveyance surface Da is set to be about the gap of the double-side conveyance path D, and serves as a conveyance surface that guides the recording surface side of the toner patch T of the color measurement unit 10. Function. The upstream portion of the front surface of the color measurement unit 10 is provided with an inclined surface that is inclined so that a gap with the transport surface Da gradually widens toward the upstream end.
At the time of the color measurement of the toner patch, the front surface 12b of the colorimeter cover 12 conveys the recording material P on the conveyance surface by the urging force of the urging member 18 (which does not affect the toner image and does not hinder the conveyance). The recording material P is conveyed while being pressed by Da and held between the colorimetric unit 10 and the conveyance surface Da. This is to convey the recording material P in a state in which the variation in the distance between the recording material P and the colorimeter 11 in the colorimetric unit 10 is reduced as much as possible. Thus, the colorimetric toner patch T formed on the recording material P can be stably read, and the colorimetric accuracy of the toner patch T can be ensured with high accuracy.

In addition, a white reference plate 30 as a reference portion is disposed on the transport surface Da, which is a facing portion to which the color measurement unit 10 faces. This is a reference for color measurement of the toner patch, and color reproducibility is guaranteed by measuring the color of the toner patch T of the recording material P before measuring the color.
That is, before measuring the toner patch T of the recording material P, the front surface 12b of the colorimeter cover 12 of the color measurement unit 10 is moved to a contact position with the conveyance surface Da and is brought into close contact with the white reference plate 30 ( (Refer FIG.4 (b)). At that time, the white reference plate 30 is color-measured and stored in the main body control unit 55 as a reference color. Thereafter, as described above, the color of the toner patch T of the recording material P is measured, and the color correction data is created by comparing the stored reference color information with the color measurement result of the toner patch. To give feedback.

(Configuration of color measuring unit and operating mechanism)
Next, with reference to FIG. 1, the color measurement unit 10 constituting the color measurement device 100 and the operation mechanism 22 for realizing the advance / retreat operation (contact / separation operation) of the color measurement unit 10 with respect to the double-sided conveyance path D will be described in detail. To do.
FIG. 1 is a schematic perspective view showing a colorimetric unit 10 and its operation mechanism according to the first embodiment. FIG. 1A is a perspective view of the colorimetric unit 10 as viewed from the front side, and FIG. FIG. 2 is a perspective view of the color measurement unit 10 of FIG.
Configuration of the shutter 14 and the colorimetric window 11a of the color measuring unit 10 The color measuring unit 10 includes the color measuring device 11, the color measuring device base 13, the color measuring device cover 12, and the shutter 14 as described above. These are integrated and can be moved in the contact direction X and the separation direction opposite to the contact direction X. Colorimeter base 13 and the colorimeter cover 12, is as described in FIG. 4, here, mainly explained with the shutter 14 and the colorimetric window 11 a provided on the colorimeter 11.
The shutter 14 is interlocked with the color measurement unit 10 so that the shutter 14 opens when the color measurement unit 10 is in the contact position (first position), and the color measurement unit 10 is in the separation position (second position). The shutter 14 is closed at a certain time.
The color measuring window 11a is provided on the front surface of the color measuring device 11 of the color measuring device 11, and through this color measuring window 11a, the toner patch T of the recording material P on the conveying surface Da and the white reference plate on the conveying surface Da. Measure 30 images. A colorimetric window 12 a corresponding to the colorimetric window 11 a of the colorimeter 11 is also formed on the front surface 12 b of the colorimeter cover 12.
The shutter 14 is constituted by a thin plate disposed along the front surface of the colorimeter 11 and swings along the front surface of the colorimeter 11 via the support shaft 14b, thereby bringing the colorimeter window 11a into the contact direction X. On the other hand, it opens and closes across the orthogonal direction. The support shaft 14b rotatably supports one end portion of the shutter 14 with respect to the colorimeter base 13. The light shielding surface portion 14a of the shutter 14 closes the colorimetric window 11a and a closed position where the colorimetric window 11a is closed. It swings between the open position where it opens. The support shaft 14b extends parallel to the contact direction X, protrudes to the back side of the colorimeter base 13, and a lever 14c for rotating the shutter 14 is attached to the protruding end.

The structure of the operating mechanism 22 The operating mechanism 22 includes a motor 20 as a drive source, a worm 16 attached to the output shaft of the motor 20, and a cam gear 17 that meshes with the worm 16. The cam gear 17 has a configuration in which a worm wheel 17c that meshes with the worm 16 and constitutes a worm gear, and a rotating cam 170 are integrated with a common rotating shaft 17b, and the rotating cam 170 is rotated by the rotation of the worm wheel 17c. Further, the slide cam 15 is engaged with the rotary cam 170 and linearly reciprocates by a predetermined distance by the rotational movement of the cam gear 17. The moving direction of the slide cam 15 is a direction orthogonal to the conveyance direction Y of the recording material P and orthogonal to the contact direction X of the color measurement unit 10. Of the movement directions of the slide cam 15, the movement direction in one direction is defined as the forward movement direction F, and the movement direction in the other direction is defined as the backward movement direction H.
The motor 20 is fixed to a main body frame (not shown), and the output shaft of the motor 20 is oriented in a direction perpendicular to the recording material conveyance direction Y of the slide cam 15 and perpendicular to the operation direction of the color measurement unit 10. ing. The rotation of the motor 20 is converted by the worm 16 into a direction parallel to the contact direction X of the colorimetric unit 10 with the rotation axis of the cam gear 17.

The slide cam 15 is supported so as to be movable in the slide direction (F, H) and immovable in the transport direction Y and the contact direction X. The slide cam 15 is arranged on the back side of the color measuring device base 13 of the color measuring unit 10 at a predetermined interval in the direction opposite to the contact direction X. The configuration of the slide cam 15 includes a cam main body 150, a cam receiver 151 provided at one end of the cam main body 150 in the sliding direction (F, H), and a shutter provided at the other end of the cam main body 150 in the sliding direction. And a pressing portion 15d. The shutter pressing portion 15d is provided so as to bend at the tip of the extension piece 15d1 extending from the other end of the cam main body 150. The shutter pressing portion engages with the lever 14c when the slide cam 15 reciprocates, and the shutter 14 Press in the closing direction.
The cam main body 150 is a frame body in which both ends of a pair of upper and lower slide pieces 15e, 15e extending in parallel with each other in the slide direction with a predetermined interval are connected by vertical pieces, and a space between the slide pieces 15e, 15e is formed. The urging member 18 is disposed by using it.
The cam receiving portion 151 is constituted by a plate-like portion orthogonal to the contact direction X, and is provided with a rectangular opening 152 into which the rotating cam 170 of the cam gear 17 is fitted. The opening 152 has first and second cam receiving surfaces 15a and 15b that are two inner surfaces facing each other extending in a direction orthogonal to the sliding direction, and two facing each other extending in a direction parallel to the sliding direction (F, H). There are two inner side surfaces 15g1, 15g2. Of the two inner surfaces extending in the direction orthogonal to the sliding direction, the first cam receiving surface 15 a is far from the cam main body 150, and the second cam receiving surface 15 b is close to the cam main body 150.
The rotating cam 170 of the cam gear 17 is an egg-shaped plate cam fixed to the rotating shaft 17b. When the portion with the largest radius of the cam surface is the top cam surface 17a, the major axis of the rotating cam 170 is the first cam receiving surface. It is equal to the distance between 15a and the 2nd cam receiving surface 15b. On the other hand, the two inner side surfaces 15g1 and 15g2 parallel to the sliding direction are configured such that the top cam surface 17a of the rotating rotating cam 170 does not interfere , and the distance between 15g1 and 15g2 is the same as the top cam surface 17a. The intervals do not interfere . As the cam gear 17 rotates, the slide cam 15 reciprocates in the slide direction.

The contact portion 13a of the engagement piece 130 that contacts the slide piece 15e of the slide cam 15 has a predetermined range between the forward movement limit and the backward movement limit of the back surface of the slide piece 15e as the slide cam 15 reciprocates. Move back and forth. Here, the forward motion direction F is the direction in which the cam body part 150 of the slide cam 15 from the rotation shaft 17b of the rotating cam 170 moves away, backward direction H is the direction to which the cam body 150 approaches the rotation shaft 17b of the rotary cam 170 is there.
The back surface of the slide piece 15e is a slope 15c that inclines in a direction gradually approaching the conveyance surface from the backward movement limit toward the forward movement limit in the sliding range of the contact portion 13a. That is, the back surface of the slide piece 15e is configured to have a step having a first surface 15e1 far from the transport surface Da and a second surface 15e2 close to the transport surface Da across the slope 15c. Further, a click portion 15f is formed so as to protrude from a boundary portion between the inclined surface 15c and the first surface 15e1 far from the transport surface Da.
In FIG. 1, the contact portion 13a is located in the forward limit position, that is, near the boundary between the inclined surface 15c and the second surface 15e2 close to the transport surface Da, and holds the colorimetric unit 10 in the contact position. Show.
The top cam surface 17a of the cam gear 17 is positioned on the second cam receiving surface 15b, and the shutter pressing portion 15d is engaged with the lever 14c while the slide cam 15 is in the forward movement limit (the colorimetric unit 10 is in the contact position). In other words, the shutter 14 is in the open position in the free state. When the slide cam reaches the backward limit (the colorimetric unit 10 is in the separated position), the shutter pressing portion 15d is engaged with the lever 14c to move the shutter 14 to the closed position.

(Description of the contact / separation operation of the color measurement unit 10)
Next, the contact / separation operation of the color measurement unit 10 will be described with reference to FIGS. 5 and 6.
FIG. 5 is a schematic view showing the relationship between the cam gear 17 and the slide cam 15 of FIG. 1, and FIG. 6 is a schematic view showing the relationship between the slide cam 15 and the colorimetric unit 10, and is a view of the slide cam 15 as viewed from below. It is. In FIG. 6, when the color of the toner patch T of the recording material P is measured, the detected material differs depending on the color measurement of the white reference plate 30 on the transport surface Da, and the contact position differs by the thickness of the recording material P. In addition, the colorimetric surface Z of the material to be detected is used. When the white reference plate 30 is not provided, the detected material may be the transport surface Da itself.
(Transition from the separated position to the contact position)
First, the operation when the color measurement unit 10 transitions from the separated position to the contact position with respect to the color measurement surface Z will be described.
Usually, the color measurement unit 10 is in a separated position retracted from the color measurement surface Z (FIG. 6A). At this time, the top cam surface 17a of the rotating cam 170 is in contact with the first cam receiving surface 15a of the cam receiving portion 151 of the slide cam 15 so as to be orthogonal to each other, as shown in FIG. At this time, the phase of the cam gear 17 is set to 0 ° (first dead point). At this time, the slide cam is positioned at the backward movement limit in the backward movement direction H. The backward movement direction H is a direction in which the cam body 150 of the slide cam 15 moves toward the cam gear rotation shaft 17b. The contact portion 13a of the engagement piece 130 of the color measurement unit 10 that contacts the slide piece 15e is located on the first surface 15e1 far from the color measurement surface Z and in the vicinity of the boundary portion with the inclined surface 15c. Is engaged with a click portion 15f protruding in the direction (see FIG. 6A).

When the motor 20 is driven from this separated position, the rotational driving force of the motor 20 is transmitted to the cam gear 17 through the worm 16, and the cam gear 17 rotates in the E direction (counterclockwise direction in the figure). When the cam gear 17 rotates approximately 90 °, the cam gear 17 starts to contact the second cam receiving surface 15b of the slide cam 15 as shown in FIG. During the transition period (between FIGS. 5 (a) and 5 (b)) from 0 ° to the contact start position of the cam gear 17 with the second cam receiving surface 15b, the slide cam 15 does not move and colorimetry is performed. The unit 10 remains maintained at a separated position away from the colorimetric surface Z.
That is, after the colorimetric unit 10 reaches the separated position (second position), there is an idle running period in which the drive is not transmitted from the rotary cam 170 to the slide cam 15.
During this time, as shown in FIG. 6A, the color measurement unit 10 is urged in the contact direction X by an urging member (not shown), and the color measurement unit 10 is urged by a guide portion (not shown). It is the structure which does not move to the left-right direction in FIG.
When the cam gear 17 further rotates, the top cam surface 17a of the rotating cam 170 starts to press the second cam receiving surface 15b of the cam receiving portion (period from FIG. 5B to FIG. 5C). The slide cam 15 starts moving in the forward movement direction F. The forward movement direction F is a direction in which the cam main body 150 of the slide cam 15 moves in a direction away from the rotation shaft of the cam gear 17.

When the driving force from the cam gear 17 starts to be transmitted to the slide cam 15, as shown in FIG. 6C, the contact portion 13a rides on the click portion 15f at the boundary between the second surface 15e2 of the slide piece 15e and the inclined surface 15c. . Thereby, the color measurement unit 10 is pushed up in the direction opposite to the contact direction X. The click portion 15f is provided for the purpose of holding the colorimetric unit 10 at the separated position, and when the slide cam 15 is about to move by an external force instead of being driven from the cam gear 17, the movement of the slide cam 15 is controlled. It works to regulate. That is, in order to move the slide cam 15, it is necessary for the abutting portion 13a of the engaging piece 130 provided on the colorimeter base 13 to get over the click portion 15f against the urging force of the urging member 18. Yes, the colorimetric unit 10 is held at the separated position by utilizing the resistance force.
When the click portion 15f passes through the contact portion 13a of the engagement piece 130 of the color measurement unit 10, the contact portion 13a of the colorimeter base 13 starts from the first surface 15e1 as shown in FIG. 6B. Move to the slope 15c. Then, due to the urging force of the urging member 18, a component force is generated by which the contact portion 13 a pushes the inclined surface 15 c in the forward movement direction F. As a result, the slide cam 15 is released from the driving force of the cam gear 17, and the relationship between the slide cam 15 and the cam gear 17 is such that the top cam surface 17a of the rotating cam 170 receives the second cam receiver as shown in FIG. It will be in the state away from the surface 15b. At this time, in the slide cam 15 and the color measurement unit 10, the front surface 12b of the color measurement unit 10 contacts the color measurement surface Z as shown in FIG. At the contact position X1, the contact portion 13a is separated from the second surface 15e2 on the side close to the conveying surface of the slide cam 15, and the colorimetric unit 10 stably contacts the colorimetric surface Z. On the other hand, when the cam gear 17 further rotates and the rotation phase reaches 180 °, the top cam surface 17a of the rotation cam 170 comes into contact with the second cam receiving surface 15b in an orthogonal state, and the slide cam 15 moves forward. The forward limit in the direction F is reached (FIG. 5 (d)).

(Explanation of operation from contact position to separation position)
Next, the operation when the color measurement unit 10 transitions from the contact position to the separation position will be described.
When the color measurement or the like is completed and the transition to the separated position is made, the motor 20 is rotationally driven. At this time, the rotation is performed in the same E direction as when the transition is made from the separated position to the contact position. That is, the drive-coupled cam gear 17 rotates in the direction E of FIG. In the present embodiment, the motor 20 is always rotated in one direction (E direction) without being driven in reverse, thereby simplifying the circuit configuration for motor control and reducing the cost. That is, the rotary cam 170 is given only one-way rotational drive from the motor 20.
When the cam gear 17 rotates and reaches the state shown in FIG. 5E, the top cam surface 17a of the rotating cam 170 starts to come into contact with the first cam receiving surface 15a of the slide cam 15. Thereafter, the cam gear 17 reaches the state shown in FIG. 5F (first dead center). The state at this time is equivalent to FIG.
On the other hand, in the slide cam 15, the cam gear 17 abuts against the first cam receiving surface 15 a during a transition period from FIG. 5D to FIG. 5E, that is, the rotation phase exceeds a predetermined amount by 180 ° to 270 °. Do not move until. Therefore, after the colorimetric unit 10 reaches the contact position (first position), there is a free running period in which the drive is not transmitted from the rotary cam 170 to the slide cam 15.
At this time, the color measurement unit 10 is urged by the urging member 18 in the contact direction X of FIG. 6, and the front surface 12 b of the colorimeter cover 12 is in contact with the color measurement surface Z by this urging force. It has become. Here, the colorimetric surface Z varies depending on the presence or absence of the recording material P. That is, when the color measurement target is the recording material P, the color measurement surface Z is the surface of the recording material P, and when the recording material P is not present, the color measurement surface Z is the surface of the white reference plate 30.
When the cam gear 17 rotates and the top cam surface 17a of the rotating cam 170 presses the first cam receiving surface 15a of the slide cam 15 during the period from FIG. 5E to FIG. The slide movement is started in the backward movement direction H opposite to the forward movement direction F.

When the drive from the cam gear 17 starts to be transmitted to the slide cam 15, the contact portion 13a of the engagement piece 130 of the color measurement unit 10 is pushed by the inclined surface 15c of the slide cam 15 shown in FIG. 10 is pushed up in the direction opposite to the contact direction X (separating direction). The contact portion 13a of the colorimeter base 13 generates a component force by which the contact portion 13a pushes the inclined surface 15c in the forward movement direction F by the urging force of the urging member 18. Since this component force becomes a resistance to the cam gear 17, the cam gear 17 moves the slide cam 15 in the backward movement direction H against the resistance force acting in the forward movement direction F. That is, the slide cam 15 moves under the control of the top cam surface 17a of the rotating cam 170. Thereafter, when the cam gear 17 rotates and the contact portion 13a of the engagement piece 130 gets over the click portion 15f of the slide cam 15, the colorimetric unit 10 reaches the separated position shown in FIG.
As described above, the urging member 18 that urges the colorimetric unit 10 in the contact direction, the motor 20, the cam gear 17, and the slide cam 15 constitute the unit drive unit of the present invention. Among these, the cam gear 17 and the slide cam 15 constitute a cam mechanism that reciprocally moves the color measurement unit 10 between a contact position (first position) and a separation position (second position). When the color measurement unit 10 is in the contact position (first position), the color measurement unit 10 is pressed against the recording material P by the urging member 18. When the color measurement unit 10 is in the separated position (second position), the color measurement unit 10 resists the pressing force of the urging member 18 by the slide cam 15 and the rotating cam 170 of the cam gear 17 constituting the cam mechanism. Are held in the separated position.

(Explanation of shutter operation)
Next, the movement of the shutter of the color measurement unit 10 will be described with reference to FIG. FIG. 7 is a diagram showing the phases of the cam gear 17 and the slide cam 15 and the movement of the shutter 14, as seen from the surface on the colorimetric window side in FIG.
( Shutter 14 when the colorimetric unit 10 transitions from the separated position to the contact position)
When the color measurement unit 10 is in the separated position, as shown in FIG. 7A, the light shielding surface portion 14 a of the shutter 14 closes the color measurement window 11 a of the color measurement device 11 that is the reading unit of the color measurement unit 10. It is arranged by. This state is the shutter closed state. The shutter 14 is rotatably held by the colorimeter base 13 around the rotation center of the support shaft 14b, and an urging force due to its own weight is applied to the shutter center of gravity G in the direction of the arrow. In the state shown in FIG. 7A, the shutter 14 is held by the rotation force due to its own weight when the lever 14 c fixed to the support shaft 14 b of the shutter 14 contacts the shutter pressing portion 15 d of the slide cam 15. .
Thereafter, as the slide cam 15 moves in the forward movement direction F as the cam gear 17 rotates, the colorimetric window 11a is gradually exposed and goes through the state of FIG. 7B to the state of FIG. 7C. Reach. When the state shown in FIG. 7C is reached, the shutter 14 is held by the receiving surface 14d coming into contact with an abutting portion (not shown) in the colorimeter cover 12, and the colorimetric window 11a is completely exposed. Fully open. This fully open state is defined as a shutter open state. That is, when the colorimetric unit 10 is in a contact state, the shutter is open.
As described above, the motor 20, the cam gear 17, the slide cam 15, and the shutter pressing portion 15d provided on the slide cam constitute the shutter drive portion of the present invention. That is, the shutter drive unit and the unit drive unit are driven by the motor 20 which is the same drive source. The shutter 14 is urged in the opening direction by its own weight, and the shutter driving unit performs driving only in the direction opposite to the urging direction of the shutter 14, in this example, the closing direction.
The shutter 14 may be urged in the closing direction by its own weight, and the shutter driving unit may be configured to drive only in the opening direction.

(Shutter 14 when the colorimetric unit 10 transits to the separated position from the contact position)
Next, the movement of the shutter 14 when the color measurement unit 10 transitions from the contact position to the separation position will be described with reference to FIG.
When the colorimetric unit 10 is in the contact position, the light shielding surface part 14a of the shutter 14 completely opens the colorimetric window 11a of the colorimeter 11 that is the reading part of the colorimetric unit 10 as shown in FIG. The shutter is open. In the state shown in FIG. 7C, the shutter 14 is held by the rotational force due to its own weight as the receiving surface 14d abuts against an abutting portion (not shown). Thereafter, as the slide cam 15 moves in the H direction as the cam gear 17 rotates, the colorimetric window 11a is gradually closed, and after the state shown in FIG. 7D, FIG. 7E (FIG. 7A )) State is reached.
At this time, the color measurement unit 10 is in a separated state, and the light shielding surface portion 14a of the shutter 14 is in a shutter closed state in which the color measurement window 11a of the color measurement device 11 that is a reading unit of the color measurement unit 10 is completely closed. . The degree of opening of the colorimetric window 11a by the light shielding surface portion 14a of the shutter 14 including the shutter open state and the shutter closed state described so far is defined as the shutter opening degree.

FIG. 8 collectively shows the relationship between the rotational phase of the cam gear 17 described above, the position of the colorimetric unit 10, and the shutter opening. In the figure, the horizontal axis indicates the phase of the cam gear 17, and the vertical axis indicates the position of the colorimetric unit 10 and the shutter opening.
As shown in FIG. 8, the phase of the cam gear 17 has a width when the colorimetric unit 10 is in the contact position and the separation position. Similarly, the cam gear 17 has a wide phase when the shutter is open and when the shutter is closed. By doing so, the stop position of the motor 20 which is a drive source for performing the contact / separation operation of the color measurement unit 10 and the opening / closing operation of the shutter 14 can be roughly set, and the control can be simplified.
In the first embodiment, a DC brush motor is used as the motor 20. The DC brush motor is inexpensive, but has a characteristic that the rotational speed changes depending on the load torque. That is, when the load torque is light, the rotation is fast, and when the load torque is heavy, the rotation is slow.

FIG. 9 shows the relationship between the phase of the cam gear 17 and the load torque applied to the motor 20 in this embodiment. In the figure, the horizontal axis represents the phase of the cam gear 17 and the vertical axis represents the load torque of the motor 20.
As shown in FIG. 9, the load torque changes differently when the colorimetric unit 10 transitions from the separated position to the contact position and when it changes from the contact position to the separated position. That is, it means that it takes longer time for the cam gear 17 to rotate 180 ° to 360 ° than to rotate from 0 ° to 180 ° in the state of FIG. That is, it takes a longer time to change from the contact position to the separation position than to change from the separation position to the contact position.

The operation mechanism of the color measurement unit 10 according to the first embodiment described above does not include a sensor or the like for detecting the phase of the cam gear 17, the slide cam 15, the shutter 14, and the like. Hereinafter, the contact position and separation position of the color measurement unit 10 and the means for detecting opening / closing of the shutter 14 according to the first embodiment will be described with reference to FIGS. 10 to 12.
FIG. 10 is a diagram illustrating the relationship between the output of the colorimeter 11 on the time axis, the shutter opening degree, and the position of the colorimetric unit 10. The horizontal axis represents time t, and the vertical axis represents the position of the color measurement unit 10, the opening of the shutter 14, and the output of the colorimeter 11.
FIG. 11 is a block diagram of the motor 20 control in the first embodiment. FIG. 12 is a flowchart for determining the contact position or the separation position of the color measurement unit 10 in this embodiment.
The colorimeter 11 outputs a first output when the shutter 14 is open, and when the shutter 14 is closed, due to a difference in color measurement target when the shutter 14 is open and when the shutter 14 is closed. Output a second output. That is, the color measurement target when the shutter 14 is opened in the absence of the recording material is an image of the white reference plate 30 that is a reference portion provided on the transport surface Da facing the colorimeter 11. On the other hand, the colorimetric object when the shutter 14 is closed is an image of the facing part of the shutter 14 that faces the colorimeter 11.
The main body control unit 55 stores the first output and the second output in advance, and activates the colorimeter 11 when the shutter 14 is opened and closed. When the output from the colorimeter 11 is the first output, it is determined that the shutter 14 is open, and when the output is the second output, it is determined that the shutter 14 is closed. Alternatively, the position of the color measurement unit 10 is determined as the contact position (first position) at the time of the first output, and the position of the color measurement unit 10 is determined as the separation position (second position) at the time of the second output. It is to be determined.
In the first embodiment, the color of the shutter 14 is black. As shown in FIG. 10, when the colorimetric unit 10 is in the separated state, the colorimetric window 11a is blocked by the shutter 14, so that the black output V (second output) that is the color of the shutter 14 is obtained. Sent from the colorimeter 11 to the main body control unit 55. On the other hand, when the colorimetric unit 10 is in contact, that is, when the colorimeter 11 performs colorimetry when the shutter is in the open state, the colorimetric window 11a faces the white reference plate 30. Output W (first output) is sent from the colorimeter 11 to the main body controller 55. That is, different outputs are detected by the colorimeter 11 between the shutter closed state and the open state.
Therefore, in this embodiment, the difference in output obtained by the colorimeter 11 between the shutter closed state and the shutter open state is used as a base for detecting the opening / closing of the shutter and the contact / separation of the colorimetric unit 10.
However, if it is simply determined that the shutter 14 is closed and the colorimetric unit 10 is in the separated position when the output is V, and the shutter 14 is open and the colorimetric unit 10 is the contact position when the output is W, Problem arises.
That is, as shown in FIG. 10, since the opening degree of the shutter 14 and the position and phase of the colorimetric unit 10 do not coincide with each other, if only the output based on the opening degree of the shutter 14 is determined, contact is also made in the section J in FIG. There is a risk of judging. Further, depending on the characteristics of the colorimeter 11, when the colorimetric window 11a is opened to some extent, the same output as when the colorimetric window 11a is fully open may be returned. That is, even if the shutter 14 is not fully open, it may be determined that the shutter 14 is fully open.

Here, control of the main body control unit 55 when the color measurement unit 10 transitions from the separated position to the contact position will be described with reference to FIGS. 10 and 11.
First, the motor 20 is rotated by a signal from the main body control unit 55.
At this time, since the colorimetric unit 10 is in the separated position, the output of the colorimeter 11 detects the black output V. When the motor 20 rotates, the shutter 14 transitions to the open state by the mechanism described above. When the motor 20 starts to drive for a while, the output of the colorimeter 11 detects a white output W as shown in FIG. The main body control unit 55 determines that the colorimetric unit 10 has reached the contact state after the elapse of ta after detecting the output W, and the main body control unit 55 stops the rotation of the motor 20. On the other hand, during the operation from the contact position to the separation position, the motor 20 is rotated in the same manner, and after the output V is detected, it is determined that the color measurement unit 10 has reached the separation state after tb has elapsed, and the main body control unit 55 Stops the rotation of the motor 20. In the first embodiment, the motor 20 is stopped not at the start of motor rotation but at the time from the time when the output of the colorimeter 11 becomes W or V. This is because the rotational speed of the motor 20 is not constant as described above. By doing so, it is possible to reliably detect the contact / separation of the color measurement unit 10 and the opening / closing of the shutter at a low cost.

Control Flowchart FIG. 12 shows a control flowchart in the main body control unit 55.
When the contact or separation instruction is given, the motor 20 starts to be driven (STEP 1), and the colorimeter 11 continuously performs the color measurement operation while the motor 20 is being driven (STEP 2, 3). The term “continuous” as used herein means that measurement is performed by operating the colorimeter 11 a plurality of times (receiving light a plurality of times) at a short sampling period t0 during which the change in the output of the colorimeter 11 can be sufficiently detected during the opening / closing operation of the shutter 14. It is to perform color operation.
In the case of a contact instruction, it is determined that the colorimetric unit 10 is in the contact position during a part of the period in which the output of the colorimeter 11 is W (period A in FIG. 10), and the output is W If not, the color measurement operation is repeated (STEP 4). In the case of the separation instruction, it is determined that the colorimetric unit 10 is in the separation position during a part of the period when the output of the colorimeter 11 is V (period B in FIG. 10), and the output is not V. If so, the color measurement operation is repeated (STEP 4).
In the case of the contact instruction, it is determined that the colorimetric unit 10 has reached the contact state after the elapse of ta after detecting the output W (STEP 5), and the rotation of the motor 20 is stopped (STEP 6). On the other hand, in the case of the spacing instructions, it is determined that the color measurement unit 10 reaches the abutment after tb elapses after detecting the output V (STEP5), stops the rotation of the motor 20 (STEP6). Thereby, the colorimetric unit 10 can be positioned at the contact position or the separation position.
In the first embodiment, the shutter open state is not detected independently since the shutter is in the open state when the colorimetric unit 10 is in the contact position. Similarly, if the shutter open and closed states are detected independently, a part of the period during which the output of the colorimeter 11 is W (period N in FIG. 10) may be determined to be the shutter open state. . Further, a part of the period in which the output of the colorimeter is V (period O in FIG. 10) may be determined to be in the shutter closed state.

  Further, the motor 20 in the present embodiment has a characteristic that the rotation speed varies according to the load torque as described above. This load torque varies according to the friction between the abutting portion 13a of the colorimeter base 13 and the slide cam 15 in FIG. 6, the biasing pressure of the biasing member 18, the environment, and the like. The output of the motor 20 and the output of the colorimeter 11 also have machine differences and environmental fluctuations. Therefore, the time on the horizontal axis and the output on the vertical axis shown in FIG. 10 vary depending on the situation. Therefore, in the present embodiment, the initialization operation is automatically performed before the contact / separation operation is actually performed.

(Initialization operation)
The operation of the initialization operation will be described below.
When the power of the image forming apparatus is turned on or before actually performing the color measurement operation, the motor 20 is rotated for a predetermined time. This time is sufficiently longer than one cycle shown in FIG. 10, and the contact / separation operation of the color measurement unit 10 is performed at least once, that is, for one cycle. During this time, the colorimetric operation (sampling period t0) is continuously performed by the colorimeter 11, and the main body control unit 55 performs the contact / separation cycle (t1, t2, t3, t4) and the amplitude as shown in FIG. The output changes of outputs W and V are stored.
That is, the time t1 that is the output V, the transition time t2 from the output V to the output W, the time t3 that is the output W, and the transition time t4 from the output W to the output V are stored. Based on the stored cycle information, ta and tb are determined. For example, ta is set so that the cam gear 17 is reliably stopped when the horizontal cam gear phase in FIG. 5 is between 120 ° and 270 °, such as 10% of t3.
Similarly, tb is set so that the cam gear 17 is surely stopped when the phase of the cam gear on the horizontal axis in FIG. 5 is between 0 ° and 90 °. Further, when storing the outputs W and V, which are amplitudes, in the main body control unit 55, values obtained by cutting the upper and lower percentages of the actual output amplitude are set as reference values, and outputs exceeding the reference values are set as W and V, respectively. It is desirable to do. By doing so, the colorimetric variation of the colorimeter 11 can be absorbed.
As described above, according to the first embodiment, the open / closed state of the shutter 14 is determined using the difference between the output when the shutter 14 of the color measurement unit 10 is opened and the output when the shutter 14 is closed. In addition, the contact / separation position of the color measurement unit 10 can be detected.
Therefore, it is possible to perform contact / separation control of the color measurement unit 10 without newly adding an opening / closing detection or contact / separation detection means of the shutter 14, and cost reduction can be achieved.

[Embodiment 2]
Next, Embodiment 2 of the present invention will be described with reference to FIG.
FIG. 13 is an enlarged cross-sectional view of the color measuring device in the present embodiment.
In the first embodiment, the white reference plate 30 is disposed on the color measurement surface Z facing the color measurement unit 10. On the other hand, in the second embodiment, the white reference plate 30 is disposed on the back of the shutter 114, and the opposed portions of the color measurement unit 10 are formed in a color that outputs different from the white reference. Note that the driving configuration and control specifications of the color measurement unit 10 in the second embodiment are the same as those in the first embodiment, and therefore the same components are denoted by the same reference numerals and description thereof is omitted.
In the second embodiment, the white reference plate 30 is disposed behind the shutter 114. In the embodiment in which the shutter 14 is housed inside the colorimetric unit 10 as in the first embodiment, the distance from the colorimeter 11 is different when measuring the white reference plate 30 and when measuring the recording material P. It will be different. Therefore, in the second embodiment, the shutter 114 is provided outside the color measurement unit 10, and when the color measurement unit 10 moves to the contact / separation position, the entire color measurement unit 10 straddles the shutter 114. It was configured to move forward and backward.
In the case of the second embodiment, the output in the case of the white reference plate 30 of the colorimeter 11 is W, and if the opposite conveying surface is black, the output is V, and the line of the colorimeter output in FIG. In the figure, the output part of W is V and the output part of V is opposite to W. Therefore, it is only necessary to determine that the section A in which the output is V is in contact and the section B in which the output is W is separated.
As described above, according to the present invention, even when the white reference plate 30 is disposed behind the shutter 114, the distance between the colorimetric surface Z, the white reference plate 30, and the recording material P can be matched. Therefore, the open / closed state of the shutter 114 can be detected by utilizing the difference between the output when the shutter 114 of the color measurement unit 10 is opened and the output when the shutter 114 is closed. The position can be detected.
Therefore, it is possible to perform contact / separation control of the color measurement unit 10 without newly adding shutter opening / closing detection or contact / separation position detection means, and cost can be reduced.

[Other embodiments]
In the first and second embodiments, the positional relationship between the colorimeter 11, the shutter (14, 114), and the white reference plate 30 is different from each other. However, the present invention is not limited to these, The positional relationship and configuration may be different from those in the example.
For example, in the first and second embodiments, the position of the colorimetric surface Z from the colorimeter 11 is substantially the same for both the white reference plate 30 and the recording material P. However, when the focal length of the colorimeter 11 is variable or the depth of focus has a sufficient width, a white reference plate 30 is provided in the colorimetric unit 10 as shown in FIG. A shutter 214 may be arranged.
In that case, the recording material P is not necessarily sandwiched as in the first and second embodiments. For example, as shown in FIG. 14A, the recording material P is conveyed along the color measurement unit 10, or along the opposite conveyance surface Da of the double-sided conveyance path D as shown in FIG. Thus, a system for conveying the recording material P can be considered.
That is, in the configuration of FIG. 14A, the color measuring unit 10 is configured by a color measuring cover 12 as a cover member covering the color measuring instrument 11, and the color measuring cover 12 is brought into contact with the recording material P to make a recording material. In this configuration, the distance between P and the colorimeter 11 is kept constant. A shutter 214 having a white reference plate 30 is disposed inside the colorimeter cover 12, and the colorimetric unit 10 is immovable without moving forward and backward with respect to the opposite conveying surface Da, and the recording material P is colorimetrically measured. It is conveyed along the front surface of the vessel cover 12.
In the configuration of FIG. 14B, the colorimetric unit 10 is configured by the colorimeter cover 12 as a cover member that covers the colorimeter 11, and the shutter 214 including the white reference plate 30 is the colorimeter cover 12. Is placed inside. The color measurement unit 10 is fixed without moving forward and backward with respect to the opposite conveyance surface Da, and the recording material P is separated from the colorimeter cover 12 and conveyed along the opposite conveyance surface Da. ing.
When the system as shown in FIG. 14 is adopted, the abutting / separating operation of the color measurement unit 10 is not necessary, and the shutter 14 using the output of the colorimeter 11 according to the control specifications described in the first embodiment. It is only necessary to detect the opening / closing of. In this case as well, detection is possible because the output of the colorimeter 11 differs between the shutter open state and the shutter closed state.
In the above embodiment, the white reference plate 30 is used as a reference, but a reference chart having reference colors of each color may be employed instead of the white reference plate 30. Further, these reference plates and reference charts may be omitted as long as the performance as a color measurement unit can be guaranteed. The present invention can be applied to a configuration in which the output of the color measurement device is different between the shutter open state and the shutter closed state.
In each of the above-described embodiments, the color measurement unit that measures a color patch image is described as an example of the color measurement device. However, a color measurement unit that measures a monochrome patch image may be used. In addition, the detection device can be used for an imaging device that picks up an image of the surface property of a recording material and discriminates the type of the recording material, rather than measuring the color of a patch image, such as a so-called media sensor.

10 ... Colorimetric unit (main unit)
11 ... Colorimeter, 11a ... Colorimetric window (opening)
14 ... Shutter (opening / closing member)
30 ... White reference plate (reference part)
55 ... Main body control unit (control unit)
100: Color measuring device (detecting device)
A: Period for determining the contact position, B: Period for determining the separation position P: Recording material X: Contact direction V: Black (shutter) output (second output) )
W: White (reference plate) output (first output)
LBP ... Laser beam printer (image forming device)

Claims (12)

A light emitting element that emits light to the material to be detected;
A light receiving element that receives reflected light from the material to be detected;
An opening and closing member that opens and closes an opening through which light emitted from the light emitting element and reflected light from the detected material pass;
A control unit for controlling movement of the apparatus main body and opening / closing of the opening / closing member;
The opening and closing member is opened in response to the movement of the apparatus main body to a first position where the apparatus main body abuts on the detected material, and the apparatus main body moves to a second position separated from the detected material. In the detection device that closes the opening and closing member according to
The light receiving element outputs a first output when the opening and closing member is open, and outputs a second output different from the first output when the opening and closing member is closed,
The control unit receives the reflected light from the detected material a plurality of times by the light receiving element during the opening / closing operation of the opening / closing member, and the light receiving element outputs the first output in advance during the period. the duration of the part which defines and judged when the closing member is open, the closing member advance period portion which defines within a period in which the light receiving element is outputting the second output is closed If they are not equal, a detecting device, characterized in that the judgment. The detected material is transported along a transport path in the image forming apparatus,
The detection apparatus according to claim 1, wherein the apparatus main body is arranged at the first position of the conveyance path, and the detection target material is conveyed along the apparatus main body. . The detected material is transported along a transport path in the image forming apparatus,
2. The detection according to claim 1, wherein the apparatus main body is disposed at the second position of the conveyance path, and the detection target material is conveyed along an opposite conveyance surface. apparatus. A light emitting element that emits light to the detected material, a light receiving element that receives reflected light from the detected material, light emitted from the light emitting element, and reflected light from the detected material pass through. An opening and closing member that opens and closes the opening;
A control unit for controlling movement of the apparatus main body and opening / closing of the opening / closing member;
The opening and closing member is opened in response to the movement of the apparatus main body to a first position where the apparatus main body abuts on the detected material, and the apparatus main body moves to a second position separated from the detected material. In the detection device that closes the opening and closing member according to
The light receiving element outputs a first output when the opening and closing member is open, and outputs a second output different from the first output when the opening and closing member is closed,
The control unit receives the reflected light from the detected material a plurality of times by the light receiving element during the opening / closing operation of the opening / closing member, and the light receiving element outputs the first output in advance during the period. the apparatus main body period portion which defines is judged to be in the first position, the device in advance period portion which defines within a period in which the light receiving element is outputting the second output body detection device, characterized in that it judged to be in the second position. The control unit performs an opening / closing operation of the opening / closing member at least once before detecting the detected material,
Sensing apparatus according to any one of claims 1 to 4, characterized in that storing a cycle of the output change of the light receiving element. The light receiving element, the a sensor for colorimetry color of the detected member, the detection according the any one of claims 1 to 5, characterized in that used as the color measuring device of the detectable material apparatus. The detection device according to claim 6 , wherein the light receiving element measures a color of a patch image as the detected material formed on a recording medium. The detection apparatus according to claim 7 , further comprising a reference unit serving as a reference when the patch image is color-measured before the color measurement of the patch image. The detection device according to claim 8 , wherein the reference unit outputs the first output at a portion detected by the light receiving element when the opening / closing member is open. The detection device according to claim 8 , wherein the reference unit outputs the second output at a portion detected by the light receiving element when the opening / closing member is closed. The light receiving element, the a sensor for imaging the surface texture of the detected member, wherein any one of claims 1 to 5, characterized in that it is used as a device for determining the type of the detecting material Detection device. Claims 1 to 1 1 detecting apparatus according to any one of the sections is, the image forming apparatus characterized by being arranged to face the transport path of the recording medium as an object to be detected material.