JP3158571B2 - Image reading 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 reading apparatus having a function of detecting a document size and executing an image reading operation based on the detected document size.

[0002]

[Prior art]

(1) A copying machine having a document size detection function is provided. For example, in the device described in JP-A-1-306829,
At the timing when the document size is to be detected, a plurality of reflection type document detection sensors are positioned below the platen glass, and any of the sensors detects the document and none of the sensors detects the document. The original size is specified by the combination. For example, in FIG. 1, the sensor SW-A3,
When the SW-A4Y does not detect a document and other sensors detect the document, the document size is specified as “B4 size”.

The above-mentioned reflection type document detecting sensor is composed of a light emitting element and a light receiving element. Light emitted from the light emitting element toward the original platen glass is reflected and received by the pair of light receiving elements. In this case, it is a sensor that detects that "the document exists". Based on the detected document size, for example, a copying operation in an APS (automatic paper selection) mode, a copying operation in an AMS (automatic magnification selection) mode, etc.
Copying operations in various modes are executed.

(2) The reflection type document detection sensor may erroneously detect the back of the white document cover as a document. For this reason, the above-described apparatus for detecting the document size using the reflection type sensor may cause erroneous detection of white on the back surface of the document cover when the document cover is opened at a certain angle or more. When there is no document size, the document size is controlled to be detected. For example, while the original cover is being closed, the original size is controlled at a timing when the angle between the original cover and the original platen glass becomes 30 °.

In the above-described apparatus, when the document cover is completely closed and then opened again, the detected document size is reset. When a new copy operation is commanded without detecting a new document size,
The copy is prohibited and a warning is issued. This means that the original cover
If the document is opened within 30 ° and replaced with a document of a different size, the copy paper corresponding to the previous size is fed,
This is to prevent the occurrence of miscopy.

[0006]

SUMMARY OF THE INVENTION
The device described in (2), that is, when the document cover is completely closed and then reopened, the detected document size is reset, and a new document size is not detected. When a copying operation is instructed, the warning device has an advantage that the original size can be reliably detected. However, after the original is set and the original cover is closed, for example, the position of the original is corrected. If the document cover is opened even a little, the detected document size is reset.
Therefore, even if a copy operation is commanded in this state, the copy operation is prohibited, and there is a problem that a warning is issued that the document size is unknown.

When the number of documents is small, it is sufficient to manually specify the size of the document, and the above-mentioned problem may not be noticeable. However, when the number of documents is large and documents of different sizes are mixed, it is difficult to manually specify the document size each time.
Seems annoying.

The present invention has been made in view of the above circumstances, and detects an original size when an angle between the original cover and a platen glass becomes a predetermined angle while the original cover is being closed. An object of the present invention is to improve the operability of an operator with respect to an image reading apparatus which does not detect a document size in order to prevent erroneous detection of the document cover backside when the angle is smaller than the angle.

[0009]

According to the present invention, there is provided a document cover supported by a hinge member at one edge of a document table glass for holding a document on the document table glass, and a document cover closed. Document size detecting means for detecting the size of the document on the platen glass and setting it as size data for control when the angle between the document cover and the platen glass becomes a predetermined angle on the way, storage means for storing data as size estimation data, the latest by referring to the data for estimation the size at before operating the Ru opened from a state where the document cover is closed in <br/> predetermined angle Data management means for setting the size estimation data as the control size data when the past two size estimation data have the same size. A.

In the above description, the size data (= size data for control) is data used for control in, for example, the APS mode, the AMS mode, and the like. The case where the latest two past size estimation data are the same is a case where the previously detected size data and the size data detected two times before are the same size.

[0011]

When the document cover reaches the predetermined angle while the document cover is being closed, the size of the document on the platen glass is detected and set as control size data. The size data is stored as size estimation data. Next, the manuscript cover is opened once,
If the document cover is closed again without being opened beyond the predetermined angle, the document size is not newly detected. At this time, if the size indicated by the latest two past size estimation data is the same, there is a high probability that the document size will not be changed. Therefore, the previous size data (= Latest size estimation data
Is set.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in the order of [1] Principle and timing of document size detection and [2] Control of document size detection. In this embodiment, the image reading apparatus is mounted as a component of the copying machine shown in FIG.

[1] Principle and Timing of Document Size Detection FIG. 1 shows the relationship between the platen glass and the document size.
Indicates the detection principle of the document detection sensor. FIG. 3 shows a control circuit centered on a microcomputer to which a detection signal of the original detection sensor group is input. FIG. 9 shows a supporting arm 40 on which the original detection sensor group is mounted. 16 shows a state in which it has been rotated below 16.

When detecting the size of the original, the original platen glass
As shown in FIG. 1, a document detection sensor group SW-A3,
SW-B4, SW-A4T, SW-B5T, SW-A5T, SW-A4Y, SW-B5Y, SW-A6,
Each is arranged. That is, as shown in FIG. 9, the support arm 40 on which the above-mentioned original detection sensor group is mounted is rotated below the original platen glass 16 as shown in FIG. Each is located like 1.

In FIG. 1, the lower digits of the reference numerals assigned to the respective original detection sensors, ie, “SW-A3, SW-B4, SW-A4T, SW-B5T, SW-A5”
T, SW-A4Y, SW-B5Y, SW-A6 "indicates the size of the document to be detected by the sensor. However, when a plurality of sensors are turned on, as is clear from FIG. 1, the size corresponding to the sensor located at the left or upper position indicates the size of the document on the platen glass 16. The size data is used in the microcomputer of FIG.

For example, when the sensor SW-A3 is turned on, as shown in FIG. 1, if the original is properly placed, the other sensor groups SW-B4, SW-A4T, SW-B5T , SW-A5T, SW-A4
Y, SW-B5Y and SW-A6 should all be on. In this case, the "A3 size" corresponding to the sensor SW-A3 which is the leftmost sensor is adopted as the above-mentioned "size data" in the microcomputer of FIG. Alternatively, if the sensors SW-B5Y and SW-A6 are turned on and all other sensor groups are turned off, "B5Y (horizontal) size"
This is adopted in the microcomputer of FIG. 3 as the above-mentioned "size data".

Each of the above-mentioned sensors is shown as "SW" in FIG. 2, and comprises a light-emitting element (left element) and a light-receiving element (right element). That is, when light is emitted from the light emitting element toward the original platen glass 16 and the light is reflected by the original platen glass 16 and received by the light receiving element, the message “an original exists on the original platen glass 16”. Is a sensor that detects

For this reason, when there is not a document (paper having a high reflectance) on the platen glass 16 but a white cloth or the like having a high reflectance on the back of the document cover 205 (= the document cover 205 is closed). Case), each of the above-mentioned sensors
There is a manuscript on top. "

In order to prevent such erroneous detection, when there is no possibility of erroneous detection due to the white cloth on the back of the original cover 205, in other words, the original cover 205 is opened at a certain angle or more. Sometimes it is necessary to detect the document size.
On the other hand, in order to use the detected "size data" for control (= APS control, AMS control, reading control, etc.), immediately before the start of the control (= the document is replaced after the document size is detected, It is necessary to detect the document size at the timing when there is no possibility that the "size data" becomes invalid.

For this reason, in the present apparatus, while the original cover 205 is being closed, the original cover 205 and the original platen glass 16 are closed.
The document size is controlled to be detected when the angle formed by the surface becomes 30 °. Hereinafter, according to FIGS. 9 and 10, while the original cover 205 is being closed, the original cover 20 is closed.
A mechanism for detecting that the angle between 5 and the surface of the platen glass 16 has become 30 ° will be described. Note that FIG.
FIG. 5 is a cross-sectional view showing details of the vicinity of a mounting portion between a document cover 205 and a document table.

As shown in FIG. 9, a magnet 206 is provided at the right corner of the front edge of the back surface of the original cover 205 of the copying machine 100.
Is attached. The magnet 206 is located at the right corner of the front edge of the platen glass 16 where the magnet 206 should come in contact when the document cover 205 is closed.
A lead switch OSW for sensing the signal 206 is provided, and its detection signal is input to the microcomputer of FIG. The magnet 206 and the lead switch OS
W constitutes a mechanism for detecting that the document cover 205 has been completely closed.

A switch mechanism KS for detecting that the angle formed between the original cover 205 and the original glass 16 is 30 ° is provided inside the left corner of the rear edge of the original glass 16.
W is installed. The tip of the push rod 209 of the switch mechanism KSW protrudes from a base plate 208 that supports the edge of the document glass 16.

That is, as shown in FIG. 10, a bracket 210 is attached to the back surface of the rear end of the base plate 208, and the push rod 209 is moved by the upper surface of the bracket 210. The rod 209 is supported via a locking portion 209a integrally formed at a substantially central portion thereof.

The locking portion 209a and the bracket 21
A spring 211 is disposed between the push rod 209 and the upper surface of the push rod 209, so that an upward urging force is applied to the push rod 209. The biasing force is applied to the hinge mechanism 20.
7, the opening angle of the original cover 205 which is openably and closably connected is adjusted to a value of 30 °.

The lower end of the push rod 209 is linked to the right end of a pressing lever 213 rotatably supported by a support pin 214.
The sensing lever 212 of the switch mechanism KSW is operated by the left end of the switch 213.
Is moved up and down. As a result, the contacts of the switch mechanism KSW are opened and closed.

For example, while the original cover 205 is being closed, the angle between the original cover 205 and the surface of the original platen glass 16 is changed.
At 30 °, the right end is pushed down by the push rod 209, so that the left end of the pressing lever 213 is displaced upward, so that the contact portion of the sensing lever 212 is also displaced upward. As a result, the contact of the switch KSW is opened, and the switch KS input to the microcomputer in FIG. 3 is opened.
The state of W changes from the on state to the off state.

Conversely, while the original cover 205 is being opened,
When the angle between the original cover 205 and the original platen glass 16 becomes 30 °, on the contrary, the contact portion of the sensing lever 212 is displaced downward, and the contact of the switch KSW is closed.
The state of the switch KSW input to the microcomputer changes from the off state to the on state. As described above, when the document cover 205 is opened at 30 ° or more, the switch KSW is turned on, and when the document cover 205 is closed at less than 30 °, the switch KSW is turned off. By detecting the state change to the ON state) and the off edge (= the state change from the ON state to the OFF state), it is possible to detect that the angle has become 30 ° while the document cover 205 is being opened and closed.

[2] Control of Document Size Detection Next, the control executed by the microcomputer of the copying machine will be described with reference to FIGS.

[2-1] Main Routine FIG. 4 shows the main routine of the processing executed by the microcomputer of the copying machine. In the microcomputer, for example, the processing is started when the power is turned on. First, processing for initializing internal registers, memories, and the like, or processing for setting various modes of the copying machine to the standard mode is performed. (S11). Next, the processing shifts to the repetitive loop processing of steps S21 to S33 (= processing repeatedly executed at regular intervals).

In step S21, a process of receiving an input signal from various sensors or the like, or a process of outputting a control signal for controlling various operating units or the like is performed. Step S23
Then, input acceptance processing of the state of various key switches on the operation panel 75 (see FIG. 9) or output processing of a control signal for driving various display elements is performed.

The details of the document size detection processing in step S25 will be described later.

In step S27, the copy magnification is automatically set based on the original size detected in step S25 or the original size detected as a key switch input from the operation panel in step S23 (AMS). : Automatic magnification selection) or a process of automatically selecting the size of the copy paper and feeding the paper (APS: automatic paper selection). In step S29, various processes necessary for the copying operation are performed. Step S31 is a process executed by the microcomputer, and indicates processes other than those described above collectively. Thereafter, the process waits for the elapse of the loop processing repetition time, and after the elapse of the time (S33; YES), the step
Returning to S21, the same is repeated thereafter.

[2-2] Document Size Detection Processing: S25 FIGS. 5 and 6 show the document size detection processing (S25). 7 and 8 show a document size data update process (S123) executed during the document size detection process. The execution of the original document size detection process is managed by a state counter SCDETECT. In step S11, "SCDETECT = 0"
It has been.

Initially, SCDETECT = 0. Therefore, steps S111 to S115 are executed. That is, “unknown” is indicated in CDDOC (= “size data” in the claims) indicating the current document size information, and MDOC indicating the previous document size information is indicated.
(= Unknown) in (“Data for size estimation” in claims)
Are respectively substituted (S111, S113), and then "SCDETECT =
1 "(S115).

In the case of "SCDETECT = 1", while the document cover 205 is being closed, it waits for the opening angle to become 30 degrees (S121). When the opening angle reaches 30 ° (S121: YE
S), the size data CDDOC is updated (S123). While the original cover 205 is being closed, the opening angle thereof is 30 °.
Is determined by the fact that the switch KSW changes from the ON state to the OFF state and its off edge is detected, and as a result, SWDETECT is set to 1.

In the document size data updating process (S123), the document detection sensor groups SW-A3, SW-B4, SW-A4T, SW-
Based on the ON / OFF states of B5T, SW-A5T, SW-A4Y, SW-B5Y, and SW-A6, the document size is specified as shown in the flowcharts of FIGS. Substituted as size data in CDDOC. For example, if the original is detected by the sensor SW-A3 and 1 is set in SW-A3,
(S211; YES), the document size is assumed to be "A3T (vertical)", and is substituted into CDDOC as size data (S21).
3). Note that other sensors SW-B4, SW-A4T, SW-B5T, SW-A5T, SW-
A4Y, SW-B5Y, SW-A6 are also determined in the same manner as above,
Similarly, it is substituted as size data (S221 to S291).
"SCDETECT = 2" after updating the original size data
(S125).

With "SCDETECT = 2", the process waits until the document cover 205 is completely closed (S131). Original cover 20
5 is completely closed by the above-mentioned lead switch OS.
W changes from the OFF state to the ON state, the ON edge thereof is detected, and it is determined by setting 1 to SWCLOSE. If the original cover 205 is completely closed during the standby (S131; YES), "SCDETECT = 3" is set (S13).
3).

If "SCDETECT = 3", the process stands by until the document cover 205 is opened (S141). The opening of the document cover 205 indicates that the read switch OSW changes from the on state to the off state and the off edge thereof is detected.
This is determined by resetting E to zero. If the document cover 205 is opened during the standby (S141; YES), the current document size information CDDOC and the previous document size information MD
OC and OC are compared (S143). Initially, both sizes are different (S
143; NO ・ S113, S123), previous document size information MDOC
Is replaced with the current size information CDDOC (S145). Also, “unknown” is assigned to the current size information CDDOC (S
147). Thereafter, “SCDETECT = 4” is set (S149). On the other hand, if the determination is made after two consecutive documents of the same size have been detected twice in step S123, the sizes are the same (S143; YES). Proceed to “SCDETECT = 4”.

In “SCDETECT = 4”, the original cover 205 is
It waits until it is opened beyond 30 ° (S151). The fact that the manuscript cover 205 has been opened beyond 30 ° indicates that the SWET
Is reset to 0. If the opening angle of the document cover 205 exceeds 30 ° during the above standby, (S
151; YES), “unknown” is substituted for CDDOC indicating the current document size information (S137), and then “SCDETECT = 1” is set (S155). That is, the process enters a standby state for processing for updating the document size data.

As described above, as a result of the control in the apparatus of this embodiment, even if a new copying operation is instructed without detecting the document size, a document of the same size is detected twice consecutively. After that, since the previous document size is held, the copy can be performed without error without performing a complicated manual operation.

[0041]

According to the present invention, even when <br/> the document cover is Ru opened, a predetermined angle is not opened (size during the document cover is closed the same predetermined angle as the predetermined angle detected) or In this case, if the latest two past size estimation data have the same size, the size estimation data is regarded as control size data. For this reason, for example, even if a document is set and the document cover is closed, and then the document cover is opened to correct the positional deviation of the document, the copy operation is permitted if the latest two detection sizes are the same. Is done. Further, since the control is performed based on the document size detected last time, the possibility of occurrence of miscopying is low. Therefore,
Copies can be made without opening the document cover beyond a predetermined angle to detect the document size. Also, there is no need to manually specify the document size, and the operability is good.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a positional relationship between a document table glass and a document detection sensor group of a copying machine according to an embodiment.

FIG. 2 is an explanatory diagram of a detection principle of a document detection sensor.

FIG. 3 is an explanatory diagram showing a configuration of a control circuit of the copying machine.

FIG. 4 is a flowchart showing a main routine of processing executed by a microcomputer of the control circuit.

FIG. 5 is a flowchart showing a part of a document size detection process executed in the main routine.

FIG. 6 is a flowchart showing the rest of the document size detection process executed in the main routine.

FIG. 7 is a flowchart showing a part of a document size data update process executed in the document size detection process.

FIG. 8 is a flowchart showing the rest of the document size data update process executed in the document size detection process.

FIG. 9 is a perspective view showing an overview of a supporting arm on which the copying machine and a document detection sensor group are mounted.

FIG. 10 is a cross-sectional view schematically showing a mechanism for detecting an angle formed between a document cover and a document table glass of the copying machine.

[Explanation of symbols]

40 Support arm, 205 Document cover, 16 Platen glass, 209 Push rod, OSW switch,
KSW switch,

Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/04 G03G 21/00 370-512 G03G 15/00 550 G03B 27/62 H04N 1/04 106

Claims (1)

(57) [Claims] An original cover is supported at one edge of the original platen glass so as to be openable and closable by a hinge member so as to press an original on the original platen glass. When the angle between the cover and the platen glass becomes a predetermined angle, a document size detecting means for detecting the size of the document on the platen glass and setting it as size data for control, storage means for storing as the estimated data, in the before the predetermined angle during operation of the document cover is Ru opened from closed condition, with reference to the data for the size estimation, the most recent of the two previous An image reading apparatus comprising: a data management unit configured to set the size estimation data as the control size data when the size estimation data has the same size.