JPS5818640A - Detecting method for movement of endless belt recording body - Google Patents

Abstract

PURPOSE:To detect the side edge part of a recording body through simple constitution by providing a detection area at the side edge part, scanning a scanning light beam to the detection area, and photodetecting reflected light from the detection area by a photodetector. CONSTITUTION:At the side edge part of the effective photosensitive area 1a of an endless belt photoreceptor 1, a detection area 1b having a high-reflection area 6a is provided, and a photodetector 5 is arranged over it. A scanning light beam 3 is constituted to scan both the photodetection area 1a and detection area 1b. Therefore, light reflected by the high-reflection area 6a is photodetected by the photodetector 5 to detect a detection mark or the side edge part of the recording body 1, and on the basis of the detection signal, sequence control and control over a shift of the belt are exercised. Thus, only the photodetector 5 is used as a sensor for detection, so the constitution is simplified to reduced the cost.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting movement of a recording medium in a recording apparatus that moves an endless belt-like recording medium and exposes the endless belt-like recording medium to light using a light beam scanning means.

In electrophotographic image recording devices, a configuration in which an endless belt-shaped recording medium (photoconductor) is supported by multiple rollers is often adopted in order to reduce the space required for the photoconductor and make the device compact. Ru. In this type of recording apparatus, if there is a seam in the endless belt-like recording medium, this seam is detected and the jitance control of the apparatus is performed using this seam as a reference. Furthermore, when an endless belt-shaped recording medium is driven by a feed roller, the recording body may shift in the direction perpendicular to the feeding direction due to belt precision, precision of the device, etc., so to correct this, the position of the belt end must be adjusted. The deviation is detected and the deviation is controlled using this detection signal. In addition to this, there are other possible cases in which the necessary mark detection is performed as the recording medium moves, and all of them involve detection marks provided on the side edge of the recording body while the recording body moves, or by fixing the side edge of the recording body to the device. Detection is done using a detection sensor installed in the area.

The above detection sensors include conventional reflective optical sensors,
When a transmissive optical sensor is used, and when a reflective optical sensor is used, marks with different reflectances are used, and in the case of a transmissive optical sensor, a transparent or cut-out mark is configured in combination with a light-receiving element. As the detection sensor becomes larger, it becomes necessary to secure a space for arranging the detection sensor, which inevitably increases the size and cost of the device.

In view of the above-mentioned problems of the conventional method for detecting the movement of an endless belt-shaped recording medium, the present invention has a simple configuration, which enables miniaturization of the detection means, and is particularly aimed at recording apparatuses that perform exposure using a light beam scanning means. It is an object of the present invention to provide a method for detecting movement of a recording medium that can be reduced in cost.

The recording means to which the present invention is applied uses, as an endless belt-like recording medium, an electrophotographic photoreceptor in which an organic or inorganic photoconductor is provided on a base film, which is charged with a charger and then charged with a gas laser or semiconductor. In this method, an electrostatic latent image is formed on a recording medium by exposure using a light beam scanning means using a laser as a light source, and an electrostatic latent image corresponding to the light intensity of the light beam is then visualized and recorded by a developing means.

This invention utilizes the light beam obtained by the above-mentioned light beam scanning means as a light source for detecting the movement of the recording medium, and irradiates the detection area provided at the end of the recording medium each time it scans.
By receiving reflected light or transmitted light from the detection area of this light beam with a light receiving element (for example, a photoelectric conversion element such as a phototransistor or photodiode) provided in its path,
Rather than detecting the detection mark provided in the detection area or the side edge of the recording medium, the movement of the recording medium can be detected without the need for a detection light source as in the past.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In the embodiment shown in FIGS. 1 and 2, an endless belt-like photoreceptor 1 is supported by two feed rollers 2 and driven in the direction of the arrow. The photoreceptor 1 is composed of an effective photoreceptor area 1a for recording information, which is the original purpose, and a detection area 1b provided adjacent to the effective photoreceptor area 1a at one side end of the photoreceptor 1. On the other hand, the scanning light beam 3 is deflected to cover not only the effective photosensitive area 1a but also the detection area ibt, and is configured to scan both areas. A straight line 4 indicated by a chain line in FIG. 1 is a light beam scanning line. A light receiving element 5 is fixedly arranged on the device on the path of the reflected light of the light beam 3 irradiated onto the detection area 1b.

In the detection area of the recording medium 1, detection marks 6 as illustrated in FIG. 3 are provided at required locations.

FIG. 3G) is an example in which a high reflection area 6a is provided in a part of the low reflection area 7. Methods such as printing, vapor deposition, and tape adhesion are used for its production. (b), . . . (c), and (d) are examples in which a portion of the high reflection region 8 is provided with a protruding portion 6b, a recessed portion 6c, and an opening 6d. (e) and (f) are examples of detection areas when detecting the entire boundary of the recording medium 1 without providing any marks; (e) shows the presence or absence of the high reflection area 8; (f) shows the presence or absence of the low reflection area 7. It does all the detection. In the case of (f), a fixing member 9 having a high reflectance is provided in order to contrast with the low reflection area 7.

With the apparatus configured as described above, the movement of the recording medium 1 is detected as follows. During recording, the deflection range of the light beam 3 by the light beam scanning means covers the recording information scanning area 1o and the detection beam scanning area 11, as shown in FIG. It is modulated according to the information signal, and an electrostatic latent image corresponding to the light intensity is formed on the effective photosensitive area la of the recording medium 1. While scanning the detection beam scanning area 11, the light beam 3 sends a detection beam of constant light intensity to the detection area 1b of the recording medium 1, regardless of recorded information.
The reflected light reflected at the detection area is received by the light receiving element 5, and the detection mark 6 or the side edge of the recording medium 1 is detected. The movement of the endless belt-like recording device is detected by this detection signal, and necessary control is performed.

In another embodiment shown in FIG. 4, the detection area 1b provided at one side end of the endless belt-like recording medium 1 is provided with a detection mark that utilizes light transmission and blocking. , a light receiving element 5 is arranged in the optical path of the transmitted light of the light beam 3 irradiated onto the detection area 1b. Therefore, by receiving transmitted light by the light-receiving element 5, the detection mark or the side edge of the recording medium 1 can be detected in the same manner as in the embodiment described above, and the movement of the recording medium can be detected.

Several examples of detection marks used in this case are shown in FIG. FIG. 5A shows an example in which a transparent area 13 is provided in a part of the opaque area 12, and can be produced by printing the entire opaque area 12, leaving the transparent area 13 as a base film eyelet. (b), (c), and (d) are examples in which a protruding portion 12a, a recessed portion 12, and a round hole 12c are provided in a part of the opaque area 12 to serve as a detection mark. (e) is a case where offset correction is performed by detecting the boundary of the edge of the recording medium 1, and the opaque area 12 shifts due to the movement of the belt end and blocks the light beam 3 reaching the light receiving element 5. This method takes advantage of the fact that the output signal changes.

(f) shows an example in which the opaque area 12 and the transparent area 13 are arranged parallel to the circumferential direction of the belt 1.

As described above, according to the present invention, since the detection optical sensor can be made up of only a light receiving element, it is possible to reduce the size of the detection means, thereby making the device more compact and reducing costs.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of a device for carrying out the method of the present invention, Fig. 2 is a schematic diagram explaining its operation, and Fig. 3 shows several examples of detection marks used in the embodiment. FIG. 4 is a schematic view showing another embodiment of an apparatus for carrying out the method of the present invention, and FIG. 5 is a perspective view showing several examples of detection marks used in the embodiment. 1...Recording body 1a...Photosensitive area 1b.
...Detection area 3...Light beam 5...Light receiving element

Claims (1)

[Claims] In a method for detecting the movement of a recording medium in a recording apparatus in which an endless belt-shaped recording medium is moved and exposed by a light beam scanning means, a required detection mark is placed on the side edge of the recording medium outside the effective photosensitive area. Provide a detection area with
A light receiving element is provided in the path of reflected light or transmitted light from the detection area when the detection area is irradiated by the light beam scanning means, and the effective photosensitive area and the detection area are detected by the light beam scanning means during recording. At the same time, the detection area is irradiated with a detection beam of constant light intensity regardless of the distribution information, reflected or transmitted by the detection area, and the reflected or transmitted light of the detection beam is A detection method characterized by receiving light with a light-receiving element and detecting movement of a recording medium from an output signal of the light-receiving element.