JP2591471B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus having a transmission cover or a transmission frame of a facsimile apparatus and a cover or frame opening / closing mechanism such as a platen cover of a copying machine.

[0002]

2. Description of the Related Art An image processing apparatus such as a facsimile machine or a copying machine often uses a cover or a frame (hereinafter simply referred to as a cover) which can be freely opened and closed in order to fix a document on an image reading surface. In such an apparatus, the original is exchanged by opening the cover, and the reading is performed in the closed state.

For example, in a copying system in which a charge for making a plurality of copies from one document is reduced as compared with a case of making copies one by one from one document, such a system is used to calculate the charge. It is necessary to reliably detect the opening and closing of the cover. Also, depending on the device, when reading a sheet-shaped document, even if the operator presses a start button to start reading with the cover open, the device does not start reading. Open / close of the cover is detected. This is because if the cover is open and the original is not loaded yet,
This takes into account that the setting may not be completed, and that the entire surface of the original may not be focused unless the original is pressed against the reading surface with a cover.

Further, in some apparatuses, in order to protect eyes from light rays irradiated for reading an image, a document is read on condition that a cover is closed.

Therefore, such an image processing apparatus conventionally employs a mechanism for detecting whether the cover is open or closed. Typical of such a device is a microswitch or a magnetic detection switch. In case of micro switch,
The opening / closing is detected by turning on / off the actuator as the cover is opened / closed. In the case of a magnetic detection switch, one of a magnet and a magnetic sensor is arranged at a predetermined position inside the cover and at an opposing portion on the apparatus body side when the cover is closed, and magnetism is detected. When this occurs, it detects that the cover is closed.

Japanese Patent Application Laid-Open No. 62-23033 does not detect the opening / closing of a cover. However, a reflection type sensor is housed in a platen cover, and the size of a document is detected by outputting infrared rays. It has become.

[0007]

In the prior art described above, some kind of sensor is arranged on a cover or a portion of the apparatus body facing the cover, and the cover is opened or closed using the detection output of this sensor. Was to be detected. For this reason, a sensor for detecting the opening and closing of the cover, a board to which the cover is attached, and a cable for inputting the detection output of the sensor to the subsequent circuit are separately required, which not only increases the cost of the device but also frequently opens and closes In many cases, parts are attached to the cover that repeats the above, and thus there is a problem that the reliability of the cover opening / closing detection device is not always high.

Accordingly, an object of the present invention is to provide an image processing apparatus capable of detecting whether or not a cover for covering a document is open without arranging a special sensor when reading of an image is started. It is in.

Another object of the present invention is to provide an image processing apparatus capable of prohibiting image reading when a cover for covering an original is open without disposing a special sensor.

[0010]

According to the first aspect of the present invention, there are provided (a) a light source, and (b) a cover which is openably and closably disposed on a document reading surface irradiated by the light source.
(C) an image sensor for reading the original by inputting the reflected light of the light beam emitted in the direction of the original reading surface; and (d) outputting the image sensor at a predetermined scanning timing before starting the original scanning. Comparing means for comparing the signal level with a predetermined reference level; and (e) determining that the cover is closed when the comparing means determines that the light beam is equal to or higher than the above-mentioned reference level. The image processing apparatus is provided with a cover open / close determining means for determining that the cover is open.

That is, according to the first aspect of the present invention, a light source and an image sensor used for reading a document are used, and the output of the image sensor is set to a predetermined reference level at a predetermined scanning timing before scanning of the document is started. Compare. If this reference level is set slightly lower than the signal level obtained when the light reflected by the light source when the cover is closed is input to the image sensor, a signal level exceeding this can be obtained. It is possible to determine that the cover is closed.

According to the second aspect of the present invention, the cover area corresponding to the document area read at the predetermined scanning timing is constituted by, for example, a white seal or a portion coated with white, so that the cover can be opened and closed. It is easy to distinguish.

According to the third aspect of the present invention, the area corresponding to the document area read at the predetermined scanning timing is also used as a reference plate normally used for shading correction. The reference plate is usually white, but may be one of three primary colors corresponding to the colors.

Further, according to the invention of claim 4, (a) a light source, (b) a cover arranged to be openable and closable with respect to a document reading surface irradiated by the light source, and (c) a direction of the document reading surface An image sensor for reading the original by inputting the reflected light of the light beam emitted to the scanner, and (d) determining the signal level output from the image sensor at a predetermined scanning timing before starting the scanning of the original. (E) determining that the cover is closed when the comparing means determines that the light beam is equal to or higher than the reference level, and determining that the cover is open otherwise. (F) reading control means for stopping reading of the original by the image sensor when the cover opening / closing determining means determines that the cover is open. To be provided in the management apparatus.

That is, in the invention according to claim 4, a light source and an image sensor used for reading a document are used, and the output of the image sensor is set to a predetermined reference level at a predetermined scanning timing before scanning of the document is started. Compare. If this reference level is set slightly lower than the signal level obtained when the light reflected by the light source when the cover is closed is input to the image sensor, a signal level exceeding this can be obtained. It is possible to determine that the cover is closed, otherwise it is possible to determine that the cover is open. At the time of this determination, the reading of the document has not yet started. Therefore,
Depending on the device, when the cover open / close determining means determines that the cover is open, the reading of the document by the image sensor can be stopped.

According to the fifth aspect of the present invention, when reading of the document is stopped, an error display is provided to notify the operator of the fact. This error display is displayed not only when the cover is not closed but also when the cover surface is dirty, so that the operator will deal with them.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

FIG. 1 shows a main part of a facsimile apparatus as an image processing apparatus according to an embodiment of the present invention. This device includes a freely openable and closable transmission frame 13 that opens in the direction of arrow 12 with reference to a fulcrum 11. This figure shows a state where the transmission frame 13 is closed. A white sticker 14 is attached to a predetermined position on a surface 13A of the transmission frame 13 on the document reading side. In addition, near the closed position of the transmission frame 13, a fluorescent lamp 15 as a light source for irradiating a reading surface of a document (not shown) is arranged in a direction perpendicular to the paper.

Light rays emitted from the fluorescent lamp 15 are applied to the reading surface by a light-shielding cover (not shown) disposed around the fluorescent lamp 15 and a condensing optical system provided as necessary. You. The reflected light 16 due to this travels in the direction of the first mirror 17, and after being reflected by the first mirror 17, is reflected by the second mirror 18 and again the first mirror 1.
7 and is further reflected by the third mirror 19 and enters the lens 21. Then, an image is formed on the one-dimensional image sensor 22 composed of a CCD.

FIG. 2 shows a state in which the transmission frame is open. Note that, in the figure, a broken line 31 shows a state where the transmission frame 13 is closed (FIG. 1) for reference. When the transmission frame 13 is opened as shown by the solid line, the direction and intensity of the reflected light 16A by the fluorescent lamp 15 differ from the reflected light 16 of FIG. Therefore, the detection output of the one-dimensional image sensor 22 is lower than that in the case of FIG.

FIG. 3 shows a comparison of the output level of the one-dimensional image sensor due to the reflected light at this point in time before the start of reading the original. In this figure, the signal waveform 41 is shown in FIG.
2 represents a signal level output from the reflected light 16 when the reflected light 16 is incident on the one-dimensional image sensor 22, and a signal waveform 42 is output from the reflected light 16A shown in FIG. Signal level. Therefore, if a predetermined reference level V _TH is determined between the two signal levels, and this is used as a reference level for determining whether the transmission frame 13 is open or closed,
When it does not exceed this, it can be determined that the transmission frame 13 is open.

FIG. 4 shows a main part of a circuit configuration of the facsimile apparatus of the present embodiment. This facsimile apparatus has a CPU (central processing unit) 5 which is a center of various controls.
1 is installed. The CPU 51 is a bus 5 such as a data bus.
2 are connected to each part in the apparatus. this house,
The ROM 53 is a read-only memory that stores programs for performing various controls of the facsimile apparatus and fixed data. In this embodiment, the value of the reference level V _TH is also stored here. The RAM 54 is a working memory. However, a part thereof may be backed up by a battery to form a nonvolatile memory, and the reference level V _TH corresponding to each device may be stored in the nonvolatile memory.

The communication control device 55 is connected to the line 56, and transmits the read image information to another facsimile device (not shown). If the facsimile device has a receiving function, , And receives image information sent from another device. FIG. 4 omits illustration of portions that are not directly related to the description of the present invention, such as portions for recording an image.

The input circuit 57 is a one-dimensional image sensor 2
2 is a circuit for inputting the output. The display control circuit 58
This is a circuit for displaying predetermined information on the liquid crystal display panel 59. When the transmission frame 13 is open, an alarm is displayed on the liquid crystal display panel 59 as described later.
The lamp drive circuit 61 is a circuit for controlling lighting of the fluorescent lamp 15.

FIG. 5 shows the flow of image reading processing of the facsimile apparatus when a document is set and a start button (not shown) is pressed. In addition,
For the sake of simplicity, here, the processing when only one document is read is shown. CPU shown in FIG.
When the timing for performing the shading correction comes (step S101; Y), the output of the one-dimensional image sensor 22 by the reflected light of the fluorescent lamp 15 from the transmission frame 13 is taken in (step S102).
The average value of the signal levels obtained for the image information is calculated (step S103). The reason for taking the average value is to eliminate the influence of the uneven density of the white seal 14 and the error due to the difference in the reading level at each position of the scanning line before the shading correction. In this embodiment, the white seal 14 is used as a reference plate for shading correction.

The CPU 51 compares the average value of the signal levels thus obtained with a reference level V _TH preset in the ROM 53, and determines whether or not the average is equal to or higher than the reference level V _TH (see FIG. 4). Step S104). Here, the reference level V _TH is such that the reflected light from the fluorescent lamp 15 when the transmission frame 13 is closed is the one-dimensional image sensor 2.
The signal level is set slightly lower than the average value of the signal level obtained when the signal is input to the second input. This value may be stored in the RAM 54 as described above, and in the latter case, it is possible to change the reference level V _TH to a value suitable for each device as needed.

When the signal level calculated as shown by the signal waveform 41 in FIG. 3 is equal to or higher than the reference level _VTH (Y), shading correction is performed as scheduled (step S105). That is, in order to correct the difference in the illuminance of the fluorescent lamp 15 and the difference in the characteristics of the one-dimensional image sensor 22 at each position in the main scanning direction, the amplification factor of the signal at each position is corrected. After that, the image information is read from the document while performing shading correction (step S106).

On the other hand, if the signal level calculated in step S104 is lower than the reference level _VTH (N), the subsequent operations for shading correction and reading the image information of the original are stopped. An error is displayed on the liquid crystal display panel 59 shown in FIG. 4 (step S10).
7). Such error displays include, for example, "the frame is open" or "close the frame or clean the reading surface".

The former is a warning that the transmission frame 13 is open. However, as described above, even when the transmission frame 13 is closed, a similar phenomenon may occur if the reading surface is dirty and the level of the reflected light is lowered. Therefore, the latter display is also effective. Needless to say, such a display need not be performed directly on the liquid crystal display panel 59, but an error number or an error code may be displayed, and the contents corresponding to these may be described in the instruction manual of the facsimile apparatus.

In the embodiment described above, the fluorescent lamps 15 and 1
Although the case where the optical path between the two-dimensional image sensors 22 is relatively long has been described, the present invention can be similarly applied to an image processing apparatus using a so-called contact image sensor having a short optical path.

Modification

FIGS. 6 and 7 show an image processing apparatus using a contact image sensor. FIG. 6 shows a state in which the cover is open, and FIG. 7 shows a state in which the cover is closed. In this example, a light emitting diode (LE) is used as a light source.
D) 71 is used. Reading surface 72A of cover 72
Has a white seal 73 used for shading correction.
Is affixed. The amount of reflected light 76 incident on the contact image sensor 75 is larger in the case of the closed state in FIG. 7 than in the case of the open state in FIG. 6, and the difference can determine the open / closed state of the cover 72 in the same manner.

In the embodiment and the modification, the image information is read by using the one-dimensional image sensor.
A dimensional image sensor or other reading element may be used.
Further, the cover may be of a type that presses the document fixedly, or may be a type that has a function of merely pressing a moving document against a predetermined scanning surface. Can be applied.

[0034]

As described above, according to the first aspect of the present invention, a light source and an image sensor used for reading a document are used, and the image sensor is scanned at a predetermined scanning timing before scanning of the document is started. Since the output is compared with a predetermined reference level and the open / closed state of the cover is determined based on the result, the determination can be made without requiring any special parts, and the apparatus can be manufactured at low cost.
Further, since it is not necessary to attach an electric component to the cover as a movable component, the reliability of the device can be improved.

According to the second aspect of the present invention, since the predetermined area of the cover is white, the amount of reflected light is larger than that of other colors, so that it is possible to reliably determine whether the cover is open or closed. Can be.

Further, according to the third aspect of the present invention, the predetermined area of the cover is also used as a reference plate normally used for shading correction, so that the manufacture of the apparatus is simplified and the shading correction is simplified. When the reference plate is dirty, the abnormality can be detected and the image quality can be maintained.

According to the fourth aspect of the present invention, when the cover open / close determining means determines that the cover is open, the reading of the document by the image sensor is stopped. Reading can be prevented.

Further, according to the fifth aspect of the present invention, when the cover open / close determining means determines that the cover is open, an error is displayed, so that when the cover is not closed or when the cover is not closed. If the surface is dirty, the operator can be informed of this and enable a quick response.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an outline of an optical system when a transmission frame is closed according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating an outline of an optical system when a transmission frame is opened in the embodiment.

FIG. 3 is a waveform diagram showing various signal waveforms obtained from a one-dimensional image sensor at a timing when a white sticker is read in the embodiment.

FIG. 4 is a block diagram showing a main part of a circuit configuration of the facsimile apparatus of the embodiment.

FIG. 5 is a flowchart showing a flow of a document reading operation in the embodiment.

FIG. 6 is a sectional view of a main part showing a state where a cover is opened in an image processing apparatus using a contact image sensor as a modification of the present invention.

FIG. 7 is a cross-sectional view of a main part showing a state in which a cover of an image processing apparatus is closed in this modified example.

[Explanation of symbols]

11 fulcrum 13 transmission frame 14, 73 white seal 15 fluorescent light 16, 16A, 76 reflected light 22 one-dimensional image sensor 41, 42 signal waveform 51 CPU 53 ROM 59 liquid crystal display board 71 light emitting diode 72 cover 75 adhesion image sensor V _TH Reference level

Claims (5)

(57) [Claims] An original is read by inputting a light source, a cover openably and closably provided on the original reading surface illuminated by the light source, and reflected light of a light beam emitted toward the original reading surface. An image sensor; comparing means for comparing a signal level output from the image sensor with a predetermined reference level at a predetermined scanning timing before starting scanning of a document; An image processing apparatus comprising: a cover opening / closing determination unit that determines that the cover is closed when it is determined that the cover is open, and determines that the cover is open otherwise. 2. The image processing apparatus according to claim 1, wherein an area of the cover corresponding to the document area read at the predetermined scanning timing is white. 3. The image processing apparatus according to claim 1, wherein the area corresponding to the document area read at the predetermined scanning timing is a reference plate for shading correction. 4. A light source, a cover openably and closably disposed on a document reading surface illuminated by the light source, and a document read by inputting reflected light of a light beam emitted in the direction of the document reading surface. An image sensor; comparing means for comparing a signal level output from the image sensor with a predetermined reference level at a predetermined scanning timing before starting scanning of a document; Cover open / close determining means for determining that the cover is closed when it is determined that the cover is open otherwise determining that the cover is open; and determining that the cover open / close determining means that the cover is open. An image processing apparatus, comprising: reading control means for stopping the reading of the document by the image sensor when the reading is performed. 5. The image processing apparatus according to claim 4, further comprising an error display unit that displays an error when the reading control unit stops reading the original.