JPH1032679A - Original reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sense switching of an original retainer cover without using a switching sensing exclusive switch or sensor in the original reader provided with an opening/closing enable original retainer cover. SOLUTION: The original reader 1 provided with a platen glass 2 on which an original 10 is placed, an open/closing enable original retainer cover 3, a lighting lamp 4 emitting a light, and an image read sensor 7 to receive a diffused reflected light in the original 10 to obtain image information, when the original retainer cover 3 is closed is provided with a regular reflection section 8 allowing the image read sensor 7 to receive a regular reflected light when the original retainer cover 3 is closed and with a switching detection means 9 discriminating the opening closing state of the original retainer cover 3 based on the luminous quantity received by the image read sensor 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CCD (Charge C)
related to a document reading device that optically reads image information from an image drawn on a document to be read by using an image reading sensor such as an Oupled Device) or PDA (Photo Diode Array). The present invention relates to a document reading device having a cover.

[0002]

2. Description of the Related Art Generally, in a document reading apparatus such as a copying machine or a scanner, a platen glass on which a document to be read is placed and a document holding cover for bringing the placed document into close contact with the platen glass. Have. However, since the document holding cover is normally provided so as to be openable and closable, if the document holding cover is open, the document cannot be brought into close contact with the platen glass, and as a result, correct reading cannot be performed. .

[0003] For this purpose, for example, Japanese Patent Publication No. 7-3554 discloses an apparatus for detecting the opening and closing of a document pressing cover by a micro switch or a reed switch. Also, Japanese Utility Model Laid-Open No. 57-205160, Japanese Utility Model Laid-Open No. 59-1
Japanese Patent Application Publication No. 7439 or Japanese Utility Model Application Laid-Open No. Sho 59-68336 discloses an apparatus for detecting the opening and closing of a document pressing cover using a light reflection type sensor.

[0004]

In the device disclosed in Japanese Patent Publication No. Hei 7-3554, signal lines must be connected in order for the microswitches and reed switches to function. In this case, a work for connection must be performed, and a lot of trouble is required for that. In addition, since micro switches and reed switches are mechanical switches, problems such as failures and poor contact are likely to occur.

On the other hand, Japanese Utility Model Laid-Open No. 57-205160 discloses
JP-A-59-17439, or JP-A-59-17439
The device disclosed in Japanese Patent No. 68336 uses a light reflection type sensor, so that problems such as failure and poor contact are reduced, but it is still necessary to connect signal lines. Furthermore, when a light reflection type sensor is used, if a document is placed on the optical axis, there is a possibility that the document holding cover may be erroneously detected as being closed even when the document holding cover is open. is there. That is, even if the light reflection type sensor detects the closed state of the document pressing cover, correct reading may not be performed, and as a result, the reliability of the detection result is reduced.

Therefore, according to the present invention, it is possible to eliminate the necessity of connecting signal lines to these switches without using a switch or a sensor dedicated to opening / closing detection, and to set a state in which the document holding cover is closed and a state in which the document is placed. It is an object of the present invention to provide a document reading apparatus capable of detecting the open / closed state of a document holding cover while enabling distinction between the document reading apparatus and the document reading apparatus.

[0007]

According to the present invention, there is provided a document reading apparatus devised to achieve the above object, wherein a platen having a document area on which a document is placed and a non-document area on which a document is not placed is provided. A glass, a document holding cover that is provided to be openable and closable above the platen glass, and that closes the document placed in the document area in the closed state to the platen glass; and irradiates light from below the platen glass. When the illumination lamp and light from the illumination lamp are reflected by a document placed in the document area, only the diffusely reflected light of the reflected light is received, and image information is obtained from the diffusely reflected light. An image reading sensor, wherein when the document pressing cover is closed, light from the illumination lamp is specularly reflected at a position corresponding to the non-document area, and A specular reflection unit that causes the image reading sensor to receive specularly reflected light having a larger light amount than the reflected light, and compares the light amount received by the image reading sensor with a predetermined reference light amount, and the received light amount is greater than the reference light amount. If the size is larger, the image reading sensor is provided with opening / closing detecting means for recognizing that the regular reflection light from the regular reflection portion is received and determining that the document pressing cover is closed.

According to the document reading apparatus having the above-described configuration, when the document pressing cover is closed, the specular reflection portion specularly reflects the light from the illumination lamp and causes the image reading sensor to receive the light. Therefore, the amount of light received from the position corresponding to the non-document area of the platen glass by the image reading sensor includes a light quantity larger than the light quantity of the diffuse reflection light reflected by the document placed on the document area. At this time, the opening / closing detection unit compares the light amount received by the image reading sensor with a preset reference light amount. If this reference light amount is set to, for example, the amount of diffuse reflection light reflected by a white document, the open / close detection means confuses the amount of regular reflection light from the regular reflection section with the amount of diffuse reflection light from the document. Instead, the image reading sensor recognizes whether or not the image reading sensor is receiving the regular reflection light from the regular reflection section. Then, when the image reading sensor recognizes that the image reading sensor is receiving the regular reflection light from the regular reflection section, it determines that the document pressing cover is in the closed state.
In this way, the document reading device detects the open / closed state of the document pressing cover.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an original reading apparatus according to the present invention will be described with reference to the drawings. Here, a case in which the present invention is applied to a digital color copying machine that optically reads image information from a document to be read will be described as an example. As shown in FIG. 1, a document reading apparatus according to the present embodiment includes a platen glass 2, a document pressing cover 3, an illumination lamp 4, and a lamp driving unit 4a.
And a drive control unit 4b, a scanning mirror 5, an imaging lens 6, an image reading sensor 7, a regular reflection unit 8, and an open / close detection unit 9.

The platen glass 2 is made of a material (for example, glass) that transmits light, and is a document 1 to be read.
It is formed in a plane shape larger than 0, and has a document area where the document 10 is placed and a non-document area where the document 10 is not placed. Document holding cover 3
Is provided so as to be openable and closable above the platen glass 2, and adheres the document 10 placed on the document area of the platen glass 2 to the platen glass 2 in a closed state. In order to bring the document 10 into close contact with the platen glass 2, the document pressing cover 3 has a document pressing surface 3 formed on a flat surface of the same size as the platen glass 2 on the platen glass 2 side of the document pressing cover 3.
a.

The illumination lamp 4 is, for example, a platen glass 2.
And a plurality of linear halogen lamps or fluorescent lamps extending in a line in the width direction (main scanning direction) of the platen glass 2. The platen glass 2 is irradiated with light from below the platen glass 2. . Lamp driving means 4
Reference numeral a denotes, for example, a drive motor for moving the illumination lamp 4 in the length direction (sub-scanning direction) of the platen glass 2 in parallel with the platen glass 2. When the lamp driving unit 4a moves the illumination lamp 4 in the sub-scanning direction, the illumination lamp 4 emits light to the entire area of the platen glass 2.

The drive control means 4b includes a lamp drive means 4a
Is a circuit or a processing program for controlling the movement of the illumination lamp 4 according to the first embodiment. Before starting the reading of the image information from the document 10, that is, before the lamp driving means 4a moves the illumination lamp 4, the illumination or the processing program is executed. It controls the lamp driving means 4a so that the lamp 4 stops at the reference position. The reference position is a position where the image reading sensor 7 receives regular reflection light from a later-described regular reflection unit when the illumination lamp 4 starts emitting light.

The scanning mirror 5 is disposed below the irradiation position irradiated by the illumination lamp 4 (that is, in the vertical direction of the irradiation position of the platen glass 2). However,
The scanning mirror 5 moves together with the illumination lamp 4. That is, the positional relationship between the scanning mirror 5 and the illumination lamp 4 is always constant. When the imaging lens 6 receives the reflected light with respect to the light emitted by the illumination lamp 4 via the scanning mirror 5, the imaging lens 6 reduces the image superimposed on the reflected light and forms an image.

The image reading sensor 7 is, for example, a CCD or a PD.
A, the light from the illumination lamp 4
When the light is reflected by the original pressing surface 3a or the regular reflection section 8, the reflected light is received via the scanning mirror 5 and the imaging lens 6. However, in the image reading sensor 7, as shown in FIG. 2, since the scanning mirror 5 is disposed below the irradiation position irradiated by the illumination lamp 4, the reflected light from the original 10 or the original pressing surface 3a is , And only the diffusely reflected light of the reflected light is received. The diffuse reflected light is reflected light obtained by diffuse reflection that diffuses light in many directions regardless of the law of reflection when viewed macroscopically.

The specular reflection section 8 is formed so as to open and close together with the original pressing cover 3. As shown in FIG. 3, when the original pressing cover 3 is closed, the illumination lamp 4 is closed.
Specularly reflected light with directivity, and the specularly reflected light having a larger light amount than the diffusely reflected light reflected by the original 10 is
The image reading sensor 3 receives light via the scanning mirror 5 and the imaging lens 6. The specularly reflected light is reflected light obtained by specular reflection that obeys the law of reflection when viewed macroscopically, such as on a mirror surface.

As shown in FIG. 4, the specular reflection section 8
It is conceivable that a wedge-shaped recess is provided at a position corresponding to the non-document area of the platen glass 2 on the document pressing surface 3a of the document pressing cover 3. In this case, the lighting lamp 4
Is illuminated from 45 ° obliquely below the platen glass 2, the reflection surface 7 a of the regular reflection section 8 is
Has an angle of 22.5 °. Also, the regular reflection section 8
May have a concave shape whose section is drawn as an arc as shown in FIG. As described above, when the specular reflection portion 8 has a concave portion or a concave shape, wear and the like do not occur even when used for a long time.

Further, as shown in FIG. 6, the specular reflection section 8 may have a convex shape whose cross section draws an arc. In this case, since a layer of air is formed between the document pressing surface 3a and the document 10, the document 10 is not easily attracted when the document pressing cover 3 is opened, and the document can be easily replaced. As shown in FIG. 5 or FIG. 6, if the cross section of the specular reflection portion 8 is formed so as to draw an arc, the specular reflection portion 8 can prevent the original pressing surface 3 a from being inclined with respect to the platen glass 2. The image reading sensor 7 can receive a predetermined amount of specularly reflected light by absorbing the inclination.

The specular reflection section 8 is a so-called metallic sheet in which a reflective piece such as a metal piece is irregularly coated on the surface, or a so-called metallic sheet in which a reflective surface for reflecting light irregularly is deposited on the surface. A prism (trade name; manufactured by Modern Plastics Industry Co., Ltd.) may be attached to the document holding surface 3a. Even if the specular reflection portion 8 is provided at a part of the position corresponding to the non-document area on the document pressing surface 3a, the position corresponds to both the document area and the non-document area, that is, It may be provided on the entire surface of the document pressing surface 3a.

In FIG. 1, the opening / closing detecting means 9 comprises, for example, a comparison circuit or a comparison processing program. The opening / closing detection means 9 compares the amount of light received by the image reading sensor 7 with a preset reference amount of light, and Is larger than the reference light amount, the image reading sensor 7 recognizes that the regular reflection light from the regular reflection section 8 is received, and determines that the document pressing cover 3 is in the closed state. However, it is assumed that the reference light amount is set to be equal to the light amount of the diffuse reflection light from the white reference document.

The opening / closing detecting means 9 outputs an electric signal such as a voltage or a current corresponding to the amount of light received by the image reading sensor 7 during a predetermined measuring time. Or may be compared using the value obtained by calculating the output signal.
Usually, in a digital color copying machine, these output signals are converted into digital signals of about 8 to 24 bits using an A / D converter, and the digital signals are used for shading correction as necessary. After performing calculations and the like, these are used as data corresponding to the light amount. Therefore, for example, if the image reading sensor 7
In the case where a common reference light amount is used among these, the comparison of the open / close detection means 9 using the calculated data is simpler because the number of additional functional components is small. However, in the above calculation, in addition to the shading correction, a fluctuation factor of a detection value of the optical sensor such as a fluctuation of a light emission time or a light emission temperature of a lamp may be corrected.

Next, a description will be given of an operation example of detecting the open / closed state of the document pressing cover 3 in the document reading apparatus having the above-mentioned configuration with reference to the flowchart of FIG.

Document 10 placed on platen glass 2
In order to start reading image information from the scanner, the operator of the document reading apparatus 1 operates a start button (not shown).
When is pressed, the illumination lamp 4 irradiates the platen glass 2 with light at the reference position (Step 101; hereinafter, step is abbreviated as S). When the illumination lamp 4 emits light, the light is reflected by the document 10, the document pressing surface 3a, or the regular reflection section 8, so that the image reading sensor 7
These reflected lights are received via the scanning mirror 5 and the imaging lens 6 (S102). When the image reading sensor 7 receives the reflected light, the opening / closing detecting means 9 compares the received light amount with the reference light amount (S103), and determines whether or not any of the received light amounts exceeds the reference light amount. Judge (S10
4).

At this time, if the document pressing cover 3 is closed, the illumination lamp 4 emits light at the reference position, so that the specular reflection light from the specular reflection section 8 always enters the image reading sensor 7. Is done. Therefore, in the opening / closing detecting means 9, if the result of the comparison between the received light quantity and the reference light quantity indicates that there is a portion exceeding the reference light quantity, the image reading sensor 7 receives the regular reflection light from the regular reflection section 8. It is determined that the document holding cover 3 is in the closed state (S105). In the document reading apparatus 1, the lamp driving means 4a
Moves the illumination lamp 4 in the sub-scanning direction, and starts reading image information from the document 10 on the platen glass 2 (S106).

On the other hand, if the document pressing cover 3 is open, the light from the illumination lamp 4 is reflected only by the document 10, so that the diffusely reflected light from the document 10 enters the image reading sensor 7. Therefore, in the open / close detecting means 9,
As a result of the comparison between the received light amount and the reference light amount, if there is no portion exceeding the reference light amount, the image reading sensor 7 recognizes that the regular reflection light from the regular reflection section 8 is not received, and the document pressing cover 3 Is determined to be open (S10).
7). Then, the document reading apparatus 1 generates an alarm and notifies the operator that the document holding cover 3 is open (S108).

However, in the document reading apparatus 1, when the operator places the document 10 on the non-document area instead of the document area on the platen glass 2, even if the document holding cover 3 is closed, the illumination lamp 4 Since the light is reflected by the document 10 instead of the regular reflection section 8, the image reading sensor 7 does not receive the regular reflection light from the regular reflection section 8.
Therefore, the opening / closing detecting means 9 determines that the document holding cover 3 is open even if the document holding cover 3 is closed. In this case, an alarm is generated and the document 10 is placed in the non-document area. The operator can be informed that the device is located, and the reliability of the detection result is not reduced.

As described above, in the original reading apparatus 1 of the present embodiment, the open / close detecting means 9 determines whether the original is open or closed based on whether or not the image reading sensor 7 receives the regular reflection light from the regular reflection section 8. The open / close state of the holding cover 3 is determined. Accordingly, the open / closed state of the document holding cover 3 can be determined without using a switch or sensor dedicated to opening / closing detection, so that problems such as failure of the switch or sensor and poor contact do not occur. Connection of signal lines can be eliminated, and labor in a manufacturing process and a maintenance process can be reduced. In the document reading apparatus 1, if the image reading sensor 7 does not receive the regular reflection light from the regular reflection section 8, the document holding cover 3
Is not determined to be in the closed state. That is, unlike the conventional optical sensor, when the document pressing cover 3 is in the open state, it is not erroneously recognized that the document pressing cover 3 is closed, so that the reliability of the detection result by the open / close detecting means 9 can be ensured. .

The original reading apparatus 1 according to the present embodiment
In the initial state, the illumination lamp 4 is located at the reference position. When the illumination lamp 4 irradiates light at this reference position and the document holding cover 3 is closed, the image reading sensor 7 Specular reflection light from the specular reflection section 8 is received. That is, the original reading device 1
Thus, when reading of image information from the document 10 is to be started, the open / closed state of the document pressing cover 3 can be determined at that time. Therefore, the open / closed state can be determined at an early stage, and the efficiency of reading image information from the document 10 can be improved.

Further, in the original reading apparatus 1 of the present embodiment, the regular reflection section 8 is provided on the original pressing surface 3a of the original pressing cover 3, and the regular reflection section 8 causes the image reading sensor 7 to receive the regular reflection light. It has become. Therefore, there is no need to provide a switch or an optical element dedicated to opening / closing detection on the document pressing cover 3, and the configuration of the document pressing cover 3 does not become complicated. Also, the regular reflection section 8 is attached to the original pressing surface 3.
By providing it at a, the open / closed state of the document pressing cover 3 can be reliably determined, and the regular reflection section 8 can be easily formed.

In the present embodiment, the case where the specular reflection portion 8 is provided on the original pressing surface 3a has been described as an example. However, it corresponds to the non-original area of the platen glass 2 and The present invention is not limited to this as long as the image reading sensor 3 receives specularly reflected light with the cover 3 closed. For example, when the original pressing surface 3a exists only in the portion corresponding to the original region of the platen glass 2 and does not exist in the portion corresponding to the non-original region, the regular reflection portion 8 is not located on the original pressing surface 3a but in the non- It may be provided at a location corresponding to the document area.

As shown in FIG. 8, for example, the document holding cover is provided with an automatic document feeding and reading mechanism.
ment Feeder; hereinafter abbreviated as ADF) 20.
When the ADF 20 is configured to open and close integrally with the opening and closing of the document holding cover, the ADF 20 is a part of the transport document reading white reference plate 21 that is located at the document reading position and is located in the non-document area of the platen glass 2. What is necessary is just to arrange the regular reflection part 8 in the corresponding position. That is, as long as the regular reflection section 8 allows the image reading sensor 3 to receive regular reflection light in a state where the document pressing cover 3 is closed, the regular reflecting section 8 directly contacts the document pressing cover 3 as described in the above-described embodiment. May be provided indirectly on the document holding cover 3 as shown in FIG. 8, for example.

Next, another embodiment of the document reading apparatus according to the present invention will be described. As shown in FIG. 9, an original reading apparatus according to the present embodiment includes an angle sensor 31 in addition to the original reading apparatus 1 according to the above-described embodiment.
A detection control means 32 is provided.

The angle sensor 31 is composed of, for example, a micro switch or a reed switch, and detects when the document pressing cover 3 is closed from an open state. The detection control means 32 is connected to the angle sensor 31, the illumination lamp 4, and the opening / closing detection means 9. When the angle sensor 31 detects that the document pressing cover 3 is closing, the detection control means 32 turns on the illumination lamp 4. Light is radiated and the opening / closing detecting means 9 performs the processing operation.

In the document reading apparatus thus configured, when the angle sensor 31 detects that the document pressing cover 3 has been closed from the open state, the detection control means 32 irradiates the illumination lamp 4 with light at that time. Then, the opening / closing detecting means 9 performs a processing operation. That is, before the operator presses the start button, the detection of the open / closed state of the document pressing cover 3 is started, so that the detection result of the open / closed state can be obtained much earlier than in the above-described embodiment. .

Further, in this document reading apparatus, if the document holding cover 3 is in the open state, it is known by the angle sensor 31, so that the accuracy of the detection result by the open / close detecting means 9 can be further improved. . More specifically, for example, if there is a lighting device above the document reading device, the document holding cover 3 is affected by light from the lighting device even though the document holding cover 3 is open.
There is a possibility that the opening / closing detection means 9 may determine that the opening / closing state is in the closed state. However, even in such a case, if the angle sensor 31 is provided, the opening / closing state can be accurately detected.
That is, the document reading apparatus can more accurately detect the open / closed state of the document holding cover 3 without being affected by the environment.

In the embodiment described above, the case where the present invention is applied to a digital color copier has been described as an example. However, the present invention is not limited to this, and the present invention is not limited to this. For example, a scanner that can read a document optically can be used.

[0036]

As described above, in the original reading apparatus according to the present invention, the opening / closing detecting means determines whether or not the image reading sensor receives the regular reflection light from the regular reflection section. The open / closed state is determined. Therefore, since no switch or sensor dedicated to open / close detection is required, problems such as failure or poor contact of these switches or sensors do not occur, and connection of signal lines to these can be eliminated. The labor in the maintenance process can be reduced. If the image reading sensor does not receive the specular reflection light from the specular reflection section, it is not determined that the document holding cover is closed, so that the document holding cover is closed and the document is placed. Can be distinguished, and the reliability of the detection result of the open / closed state can be improved more than the conventional one.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an embodiment of a document reading apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing diffuse reflection light reflected by a document in the document reading apparatus of FIG. 1;

FIG. 3 is an explanatory diagram showing specularly reflected light reflected by a specular reflection section in the document reading apparatus of FIG. 1;

FIG. 4 is an explanatory diagram (part 1) illustrating a specific example of a regular reflection section;

FIG. 5 is an explanatory diagram (part 2) illustrating a specific example of a regular reflection section;

FIG. 6 is an explanatory diagram (part 3) illustrating a specific example of a regular reflection section;

FIG. 7 is a flowchart illustrating an operation example when the open / close state of the document pressing cover is detected in the document reading apparatus of FIG. 1;

FIG. 8 is an explanatory diagram illustrating a regular reflection portion when the document pressing cover includes an automatic document feed and reading mechanism (ADF).

FIG. 9 is a schematic configuration diagram of another embodiment of a document reading apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Document reading apparatus 2 Platen glass 3 Document pressing cover 3a Document pressing surface 4 Illumination lamp 4a Lamp driving means 4b Drive control means 7 Image reading sensor 8 Regular reflection section 9 Open / close detection means 31 Angle sensor 32 Detection control means

Claims (4)

[Claims] A platen glass having a document area on which a document is placed and a non-document area on which a document is not placed; a platen glass provided so as to be openable and closable above the platen glass; A document holding cover for bringing the placed document into close contact with the platen glass; an illumination lamp for irradiating light from below the platen glass; and light from the illumination lamp is reflected by the document placed on the document area. And an image reading sensor that receives only diffusely reflected light of the reflected light and obtains image information from the diffusely reflected light, wherein the document pressing cover is closed, Specular reflection for reflecting light from the illumination lamp at a position corresponding to a non-document area and for causing the image reading sensor to receive specularly reflected light having a larger amount than the diffusely reflected light. And comparing the light amount received by the image reading sensor with a preset reference light amount, and when the received light amount is larger than the reference light amount, the image reading sensor receives regular reflection light from the regular reflection unit. An opening / closing detecting unit for recognizing that the original is pressed and judging that the original pressing cover is closed. 2. A lamp driving means for moving the illumination lamp in parallel with the platen glass; and an initial state before the lamp driving means moves the illumination lamp. 2. The document reading apparatus according to claim 1, further comprising: drive control means for stopping the image reading sensor at a position where the image reading sensor receives regular reflection light from the regular reflection section when irradiation is started. 3. The specular reflection portion is located at a position corresponding to a non-document area of the platen glass on a document holding surface of the document holding cover for bringing a document on the platen glass into close contact with the platen glass. 3. The document reading device according to claim 1, wherein the document reading device is provided. 4. An angle sensor for detecting when the document holding cover is closed from an open state, and when the angle sensor detects that the document holding cover is closing, light is emitted to the illumination lamp. And a detection control means for irradiating the light and causing the opening / closing detection means to perform the processing operation.
The document reading device according to 2 or 3.