JP4849535B2 - Document reader - Google Patents

Description

The present invention relates to a document reading apparatus provided with a document irradiating means for irradiating a document with light when detecting a document size.

2. Description of the Related Art Conventionally, in an image reading apparatus, in order to suppress discomfort due to glare of light emitted when detecting a document size, a device that reduces the light emission amount of a document irradiation unit when detecting the document size has been proposed (for example, a patent). References 1 and 2). In addition, there have been proposed ones that cause the document irradiation unit to emit light only when the document size is detected (see, for example, Patent Documents 3 and 4), and those in which the emission color of the document irradiation unit is other than white (for example, Patent Document 5). reference).
Japanese Patent Laid-Open No. 11-24189 JP 2002-290675 A JP 2004-96157 A JP 2004-32075 A Japanese Patent Laid-Open No. 2005-051443

  In the above Patent Documents 1 and 2, since the light emission amount of the document irradiation unit must be controlled in multiple stages, the light amount adjustment and shading adjustment must be performed in each stage, leading to an increase in the adjustment sequence and initial productivity ( Adversely affects FCOT, etc.).

  In Patent Documents 3 and 4, light emission of the original irradiation unit is originally performed once when the pressure plate is closed, once when the pressure plate is completely closed, and once when the pressure plate is closed. Since the light is emitted only once, the accuracy of detecting the document size is lowered. That is, since the reflectivity of a black document is extremely low in principle, it is impossible to identify whether there is no document or a black document when the platen is closed, and thus the document size cannot be detected. This is the reason why the original irradiating unit emits light even when the pressure plate is completely closed. However, since it is omitted in Patent Documents 3 and 4, the accuracy of detecting the original size is lowered.

  In Patent Document 5, since a non-white light emitting part is required in addition to the white light emitting part, two light emitting parts are provided, which makes the structure complicated and increases the cost.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a document reading apparatus capable of suppressing discomfort due to glare of light irradiated when detecting the document size and detecting the document size with high accuracy. And

To achieve the above object, the document reading apparatus of the present invention includes a platen on which an original is placed, it is possible to open the closed, a pressure plate for pressing the placed originals on the platen during closing, Document irradiating means for irradiating a document placed on the document table from below the document table; Document reading means for reading reflected light from the document placed on the document table irradiated by the document irradiating means; , a document reading apparatus having a document size detection means for detecting the size of the document placed on the document table, based on the read information of the document reading unit, the document illumination means, the pressure plate is closed at a timing that is, flashing operate continuous, said original reading means, read-reflected light from the document placed on the document table by a portion of the lighting of the blinking, the blinking Lighting other than lighting of the part Does not read the reflected light from the document placed on the document table, and the document size detecting means reflects the reflected light from the document by turning on a part of the blinking operation read by the document reading means. The size of the document placed on the document table is detected based on the read information .

According to the present invention, the afterimage effect of blink operate the document illumination means successively, Ru can detect the size of the document with high precision while not feel glare to the human eye.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view of an image reading apparatus as an example of an embodiment of the present invention, and FIG. 2 is an explanatory diagram for explaining an internal structure of the image reading apparatus as an example of an embodiment of the present invention. FIG. 3 is an explanatory diagram for explaining the optical unit, and FIG. 4 is an explanatory diagram for explaining the document irradiation unit.

  As shown in FIG. 1, an image reading apparatus 400, which is an example of an embodiment of the present invention, is arranged on the upper surface of a document table 400a, and a document table glass 401 on which a document G is placed, and a document table 400a. A pressure plate 402 that is supported so as to be freely opened and closed and that presses the document table glass 401 when it is closed.

  A pressure plate detection lever 106 that is pushed in when the pressure plate 402 is closed is provided near the opening / closing support portion of the pressure plate 402 of the document table 400a. When the pressure plate detection lever 106 is pushed in, the pressure plate sensor 613 (see FIG. 5) detects the closed state of the pressure plate 402.

  Here, in this embodiment, the document detection cycle is operated twice after the pressure plate 402 starts to be closed and the pressure plate 402 is completely closed.

  Specifically, when the pressure plate sensor 613 detects only the start of closing of the pressure plate 402, the detection that the pressure plate 402 has been completely closed is that a predetermined time (about 3 seconds) has elapsed since the start of closing. When you do. Further, when the pressure plate sensor 613 detects a two-stage displacement between the start of closing of the pressure plate 402 and the fully closed state, the document detection is performed at the detection timing when the pressure plate 402 starts to close and completely closes. Activate the cycle.

  Also, as shown in FIG. 2, a first carriage 404, a second carriage 407, a lens 408, a CCD (original reading means) 409, and a light emitting unit 101 are arranged in the original table 400a.

  A document irradiation unit (document irradiation unit) 102 and a first mirror 403 are disposed on the first carriage 404, and a second mirror 405 and a third mirror 406 are disposed on the second carriage 407. When reading the original G placed on the original platen glass 401, the first carriage 404 and the second carriage 407 are moved by a scanner drive motor (not shown) at a predetermined relative speed so that the optical path length does not change. Driven and mechanically scanned.

  To read the original G, first, the laser light source in the laser module 1 (see FIG. 5) is driven, and the original G is irradiated with the laser light guided from the light emitting unit 101 as a linear light source by the original irradiation unit 102. The reflected light K enters the CCD 409 via the first mirror 403, the second mirror 405, and the third mirror 406, and is converted into an electrical signal (analog signal).

  In FIG. 1, reference numeral 107 denotes an opening for guiding the reflected light K reflected by the second mirror 405 and the third mirror 406 to the CCD 409, and reference numerals 2102 and 2103 denote reflective sub-scanning sensors (document size detection). Sensors 614 and 615 (see FIG. 5).

  As shown in FIG. 3, the light emitting unit 101 includes a laser module (coherent light emitting means) 1, a metal holder 2 that holds the laser module 1, and laser light output from the laser module 1 to the document irradiation unit 102. An optical fiber cord (light guiding means) 3 for guiding is provided.

  The optical fiber cord 3 uses a highly flexible optical fiber typified by POF (plastic optical fiber) in consideration of the usage situation in which the first carriage 404 on which the document irradiation unit 102 is mounted reciprocates at high speed. . Thereby, the durability of the optical fiber cord 3 is maintained, and the laser light emitted from the light emitting unit 101 is stably irradiated onto the fluorescent light emitting unit 5 mounted on the document irradiation unit 102.

  Moreover, since the light emission part unit 101 is comprised by the well-known laser light source, it needs the heat dissipation process. Therefore, by mounting the light emitting unit 101 so as to be in contact with the inner surface of the side plate of the document table 400, the room temperature can be kept substantially, and a stable light quantity can be obtained.

  As shown in FIG. 3, the document irradiation unit 102 constitutes an optical system unit 100 together with the light emitting unit 101, and is converted into a holder 4, a phosphor light emitting unit 5, a heat radiating member 6, an optical reflector 7, and a line light source. And a reflected light path 9 through which the reflected light of the original G is guided.

  As shown in FIG. 4, the laser light emitted from the phosphor light emitting unit 5 is reflected by the diffusion surface 10 provided inside the light guide 8 and directed toward the document G placed on the document table glass 401. Are emitted. The diffusing surface 10 has a fine taper surface continuously formed in the longitudinal direction of the light guide 8, and the incident angle θ to the taper surface is α or more (the light guide is made of acrylic resin and has a refractive index. The light incident at n = 1.5) satisfies the total reflection angle condition and is emitted in a desired direction. In addition, since the pitch of the taper surface is very fine as 1 (mm) or less, a uniform illuminance distribution can be obtained within a short range of the original G.

  Next, referring to FIG. 5, a control system of the image reading apparatus which is an example of the embodiment of the present invention will be described.

  As shown in FIG. 5, the control system of the image reading apparatus 400 includes a CPU 501 that is a central processing unit, a ROM (read only memory) 502, and a RAM (random access memory) 503.

  The ROM 502 stores a control program, and the RAM 503 stores input data and work data. The CPU 501 controls the laser control unit 506, the motor driver 504, and the image processing unit 508 in accordance with a control program stored in the ROM 502 connected via a bus in accordance with an instruction from the controller 520. The laser control unit 506 controls driving of the laser module 1 for document irradiation, and the motor driver 504 controls motors (not shown) for driving the first carriage 404 and the second carriage 407.

  The control system of the image reading apparatus 400 includes a sensor input unit 505 and a CCD 409 that converts incident reflected light into an image signal. The sensor input unit 505 receives detection signals from a pressure plate sensor 613 that detects opening and closing of the pressure plate 402, sub-scanning sensors 614 and 615, and other various sensors (not shown) for detecting the position of the carriage. The image signal output from the CCD 409 is A / D converted and amplified by the analog signal processing unit 507, and the image signal converted into the digital signal is subjected to shading correction by the image processing unit 508. The shading-corrected image signal is transferred to the controller 520 via the external I / F 509. The external I / F 509 transmits / receives commands and data between the controller 520 and the image reading apparatus 400.

  When the original G is placed on the original platen glass 401 with the pressure plate 402 opened and the pressure plate 402 is closed, the original size detection operation is performed according to the detection content of the pressure plate sensor 613 connected to the sensor input unit 505. To start.

  The document size detection operation will be described in detail later. First, the CCD 409 is driven, and then at a predetermined timing, a lighting control signal is input to the laser control unit 506, and the laser module 1 is driven to emit phosphor light. The part 5 is turned on and the entire light guide 8 emits light. Then, a value calculated by an n-pixel averaging circuit (not shown) based on a value supplied to a line memory (not shown) provided in the image processing unit 508, and a value obtained from the sub-scanning sensors 614 and 615 Based on the above, the contents of the RAM 503 and ROM 502 are referenced to detect the document size.

  As shown in FIG. 5, when the image reading device 400 is connected to the controller 520 and the recording unit 530, the image data read by the image reading device 400 is subjected to image processing by the controller 520 and recorded. The copying apparatus records and outputs the data in the unit 530. In addition, communication of data, image information, and the like can be performed from the image reading apparatus 400 to the FAX apparatus 540 that is the counterpart communication apparatus via the controller 520 and the public line. Furthermore, image data can be transmitted from the image reading apparatus 400 to the designated computer 550 via the controller 520 and the Internet.

  Next, an image reading operation of the image reading apparatus which is an example of the embodiment of the present invention will be described with reference to FIGS.

  FIG. 6 is a flowchart for explaining the main routine of the image reading process, FIG. 7 is a flowchart for explaining the light amount adjustment initialization process of FIG. 6, and FIG. 8 is for explaining the pressure plate reading process of FIG. It is a flowchart figure.

  First, referring to FIG. 6, when a main power switch (not shown) is turned ON or a power ON request is received from the controller 520, various power supplies are supplied to the image reading device 400. In step S <b> 601, light amount adjustment initialization processing is performed. I do.

  In step S602, it is monitored whether a main power switch OFF or a power OFF request from the controller 520, which is a transition event to the power OFF state, is received.

  If a transition event to the power OFF state does not occur in step S602, the process proceeds to step S603 to perform a pressure plate reading process. If a transition event to the power OFF state occurs, the supply power is stopped, the power Processing for turning off is performed, and the power is turned off.

  Next, the light amount adjustment initialization processing in step S601 in FIG. 6 will be described with reference to FIG.

  First, in step S701, the CPU 501 uses the CCD 409 to measure the light amount of the document irradiation unit 102 when the laser control unit 506 is driven at a constant current in order to emit a desired light amount when reading the document. Then, a current value corresponding to the target light emission amount is obtained based on the measured value, a current value corresponding to the target light emission amount is determined, stored in the RAM 503, and the process proceeds to step S702 to perform shading correction.

  In step S <b> 702, first, the laser control unit 506 performs constant current control with a reference light amount, drives the laser of the light emitting unit 101, and turns on the document irradiation unit 102. Next, the original irradiation unit 102 is moved to a standard white plate (not shown) position on the inner surface of the pressure plate 402, the density of the standard white plate is measured by the CCD 409, and the measured density data (shading data) is stored. The stored shading data is subjected to arithmetic processing at the time of image reading, and variations in each pixel of the image read by the CCD 409 during document scanning are corrected to make the image density uniform.

  Next, the pressure plate reading process in step S603 of FIG. 6 will be described with reference to FIG.

  First, in step S801, the controller 520 is in a standby state while repeatedly determining whether or not the start button for instructing reading of an original is pressed from an operation unit (not shown).

  When the document reading start button is pressed in step S801, a command for instructing to start reading the document is sent from the controller 520 to the image reading apparatus 400, and the step of turning on the document irradiation unit 102 is executed. Move to SS802.

  In step S802, the amount of original irradiation for image reading is determined, and a target current value for the amount of laser emission necessary for original irradiation is determined. Next, constant current control of the laser control circuit 506 is performed according to the determined current value, the light guide 8 is turned on, and the original G is irradiated with laser light.

  In step S803, the first carriage 404 is moved in the sub-scanning direction from a document set reference (not shown), and image information of the document G placed on the document table glass 401 is read. In reading the image information, the reflected light of the laser beam irradiated on the original G in step S802 is input to the CCD 409 via the mirrors 403, 405, 406 and the lens 408. The reflected light input to the CCD 409 is subjected to electrical processing such as photoelectric conversion and processed as a digital signal.

  Next, the image signal sent to the image processing unit 508 is corrected based on the shading data stored in step S <b> 702 and sent to the controller 520 via the external IF 509.

  After reading the document in step S803, the constant current control for the laser control circuit 506 is terminated in step S804, and the laser emission is stopped.

  Next, with reference to FIG. 9 to FIG. 16, the document size detection operation by the image reading apparatus which is an example of the embodiment of the present invention will be described.

  FIG. 9 is a time chart for one cycle of the document size detection cycle, and FIG. 10 is a time chart for a plurality of cycles of the document size detection cycle. FIG. 11 is an explanatory diagram for explaining an example of detecting an AB type document size, and FIG. 12 is an explanatory diagram for explaining an example of detecting an inch type document size. FIG. 13 is a perspective view illustrating an example of document size detection, FIG. 14 is an explanatory diagram for explaining the relationship between the main scanning detection position and the CCD reading position, and FIG. 15 is an AB system document size detection example. FIG. 16 is a diagram for explaining an example of document size detection.

   The document size detection operation by the image reading apparatus as an example of the embodiment of the present invention includes a “document size detection cycle” and a “document size detection algorithm for using the document size detection cycle to actually detect a document. ”.

  As shown in FIG. 9A, the “document size detection cycle” refers to a laser beam from the light guide 8 of the document irradiation unit 102 to the document G placed on the document table glass 401 in a very short time (about 100 μm). In this operation, light is irradiated and the reflected light is read by the CCD 409.

  On the other hand, the “original size detection algorithm” is an algorithm that actually detects the size of the original G based on the value obtained in the “original size detection cycle”.

  First, the “document size detection cycle” will be described in detail.

  FIG. 9A is a time chart for one cycle of the document size detection cycle. When the CPU 501 turns on the drive current for the laser control unit 506 at a predetermined timing, the laser module 1 fluoresces via the optical fiber cord 3. A laser is applied to the light emitting unit 5 to increase the light emission amount of the light guide 8. After a sufficient time (10 μs) for the light emission amount of the light guide 8 to rise, the reflected light is read by the CCD 409, and then the drive current is reduced.

  Here, FIG. 9B is a dummy cycle, and this cycle has the same lighting time of the light guide 8 as the cycle of FIG. 9A, but reading by the CCD 409 is not performed.

  FIG. 10 shows the relationship between the lighting operation of the light guide 8 and the reading operation by the CCD 409.

As can be seen from FIG. 10, the light guide 8 is continuously blinked by performing the lighting operation of the light guide 8 ( 100 μm at 1 ms intervals ) a plurality of times , but the CCD 409 actually reads the reflected light of the original G. Is a part of the continuous blinking operation, and the other is a dummy cycle in which the light guide 8 is simply lit.

  Turning on the light guide 8 only when the reflected light of the original G is read by the CCD 409 gives a flickering impression to the user. In this way, the light guide 8 blinks continuously. If it continues, the afterimage effect can give the impression of being continuously shining dark.

  The lighting cycle of the light guide 8 is started when the above-described pressure plate 402 is closed, and a reading cycle by the CCD 409 is inserted at a timing when the reading of the document is necessary, thereby enabling detection of the document size.

  Next, the “document size detection algorithm” will be described in detail.

  The “document size detection algorithm” detects the main scanning document width by the reading value of the CCD 409, and detects the sub-scanning document width by the reflective sub-scanning sensors 614 and 615 (only the sub-scanning sensor 614 in the case of an AB document). To do.

  FIG. 11 shows a layout when an AB document is set on the document table glass 401 of the image reading apparatus 400.

  Since the first carriage 404 has to move to the inside of the document from the image tip when reading the document main scanning width, the first carriage 404 is arranged at the document size detection position 2208 for reading the inside of the document G by about 10 to 20 mm. In order to read the document main scanning width at this position, the detection result of the sub-scanning sensor 614 is combined with the reading values of the plurality of document main scanning width detection points 2202 to 2206 provided at the left corner of the document in FIG. To detect the document size. The sub-scanning sensor 614 can be arranged in the area 2209.

  Here, for example, if a document is detected at document main scanning width detection points 2202 to 2204 and a document is also detected by sub-scanning sensor 614, the document size is detected as A4R.

  FIG. 12 shows a layout when an inch-type document is set on the document table glass 401 of the image reading apparatus 400.

  For an inch-type document, the document size is detected together with the detection results of the sub-scanning sensors 614 and 615 based on the reading values of the three types of document main scanning width detection points 2302 to 2304. Incidentally, the sub-scanning sensor 614 can be arranged in the area 2307, and the sub-scanning sensor 615 can be arranged in the area 2308.

  FIG. 13 shows an image of the detection of the document size using the CCD 409. In this example, a region 2402 other than the main scanning width of the document G indicates that light from the light guide 8 of the document irradiation unit 102 leaks and light can enter directly into the eyes of the operator.

  Next, FIG. 14 shows an image related to reading by the CCD 409 having a main scanning width. In FIG. 14, the position of the original main scanning width detection point 2503 is shifted, but when detected, reflected light is imaged on the CCD 409 via the optical lens 408. In the pixel row 2506 of the CCD 409, the pixel width 2506 has an average value of n pixels from the pixel at the position 2508 separated from the actual document width and the main scanning resolution based on the position of the document width start point 2507. Applied to detection point readings.

  Here, if a B5 size document is set, the longitudinal direction of the B5 size is 257 mm. If the position about 3 mm inside the end in the longitudinal direction is taken as the detection point, (254 × 1e−3) ÷ (25.4 × 1e−3 ÷ 600 dpi) = 254 × 1e−3 ÷ (42.3 × 1e −6) = corresponds to pixels in the vicinity of 6004 pixels. The document main scanning width can be detected by obtaining an average value from this pixel with a width of about 64 pixels (about 2.7 mm), for example. That is, it suffices if the original level can be detected when each of these detection points is instantaneously turned on.

  FIG. 15 shows a detection result in AB-based document size detection.

  In FIG. Reference numeral 0 denotes a document abutting position, which is a point for detecting the presence or absence of a document. 0 to No. 1-No. It is detected how far the original is up to 8 detection points. No. If all of them, including 0, are not detected, there is no document. As is apparent from FIG. 2, no. 3, No. 4, no. 6, no. Only 8 is used for detecting the document size.

  FIG. 16 shows a specific example of AB-based document size detection.

  In FIG. 16A, when the pressure plate 402 is closed, the pressure plate detection sensor 613 is cut by the pressure plate detection lever 106, and the main scanning detection point 801 and the sub scanning sensor 614 start the detection operation. This detection operation is repeated for a predetermined time at intervals of about 200 ms from the start.

  FIG. 16B shows the detection result when the original G is white, and FIG. 16C shows the detection result when the original G is black. When the pressure plate 402 is closed and when it is completely closed, the results in FIG. 16B and FIG. 16C differ depending on the density of the document. It is possible to detect the size by using “change”.

  That is, in FIG. 16B and FIG. 7, no. The result of No. 8 differs between when the pressure plate 402 is closed and when it is completely closed, and it can be determined that there is no document in that portion. It can be seen that the results of the other parts are the same when closing and completely closing because there is a document. This means that when there is a document, the reflected light of the document is detected whether the pressure plate 402 is closed or completely closed. On the other hand, when there is no document, reflected light does not return when the pressure plate 402 is closed, but when the platen is completely closed, reflected light from the standard white plate 804 on the inner surface of the pressure plate 402 is detected. Incidentally, in this example, both detection results are B5 size.

  As described above, in this embodiment, when the document size is detected, the light guide 8 of the document irradiation unit 102 is continuously blinked to give an impression of being continuously shining dark due to the afterimage effect. . As a result, the size of the original can be detected while preventing the human eye from being dazzled by the afterimage effect of flashing in a very short time while the light emission amount of the original irradiation unit 102 remains constant. As a result, it is possible to accurately detect the document size without complicating the adjustment of the light amount of the document irradiation unit 102 and without complicating the structure.

  In addition, this invention is not limited to what was illustrated to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  FIG. 17 shows a modification of the optical system unit. The optical system unit 1500 includes a light emitting unit 1520 and a document irradiation unit 1530.

  The light emitting unit 1520 is held by a metal holder 1502 and serves as a laser module 1501 serving as a light source for the plurality of light emitting units 1504 of the document irradiation unit 1530, and an optical fiber that guides laser light output from the laser module 1501 to the light emitting unit 1504. Code 1503.

  The document irradiation unit 1530 includes a plurality of light emitting units 1504, a light guide 1506, and a reflected light path 1507 through which reflected light 1505 of the document is guided. The control is the same as that in the above embodiment except that the lighting of the plurality of light emitting units 1504 is controlled.

1 is an external perspective view of an image reading apparatus which is an example of an embodiment of the present invention. 1 is an explanatory diagram for describing an internal structure of an image reading apparatus that is an example of an embodiment of the present invention; FIG. It is explanatory drawing for demonstrating an optical unit. It is explanatory drawing for demonstrating a document irradiation unit. FIG. 3 is a control block diagram of an image reading apparatus which is an example of an embodiment of the present invention. It is a flowchart for demonstrating the main routine of an image reading process. FIG. 7 is a flowchart for explaining light amount adjustment initialization processing of FIG. 6. FIG. 7 is a flowchart for explaining the pressure plate reading process of FIG. 6. It is a time chart for one cycle of a document size detection cycle. FIG. 6 is a time chart for a plurality of document size detection cycles. FIG. 6 is an explanatory diagram for explaining an example of detection of an AB document size. FIG. 6 is an explanatory diagram for explaining an example of detecting an inch-based document size. FIG. 6 is a perspective view illustrating an example of detecting a document size. It is explanatory drawing for demonstrating the relationship between a main scanning detection position and the reading position of CCD. FIG. 6 is an explanatory diagram for explaining an example of detection of an AB document size. FIG. 6 is a diagram for explaining an example of document size detection. It is explanatory drawing for demonstrating the image reading apparatus which is other embodiment of this invention.

Explanation of symbols

1 Laser module (coherent light emission means)
3 Optical fiber cord (light guide)
5 Phosphor light emitting part (fluorescent means)
G Document 102 Document irradiation unit (document irradiation means)
400 Image reading device 400a Document table 402 Pressure plate 409 CCD (document reading means)

Claims (5)

A document table on which the document is placed;
A possible opening and closing, the pressure plate for pressing the placed originals on the platen during closing,
Document irradiating means for irradiating a document placed on the document table from below the document table ;
A document reading unit that reads reflected light from a document placed on the document table irradiated by the document irradiation unit ;
A document reading apparatus having a document size detection means for detecting the size of the document placed on the document table, based on the read information of the original reading means,
The document illumination means at a timing when the pressure plate is closed, flash operates in continuous,
Said original reading means, read-reflected light from the document placed on the document table by a portion of the lighting of the flashing operation, the in lighting other than the part lighting of the blinking Without reading the reflected light from the document placed on the platen,
The document size detection means is configured to determine a size of the document placed on the document table based on reading information of reflected light from the document when a part of the blinking operation read by the document reading means is turned on. An original reading apparatus for detecting an original . 2. The document reading apparatus according to claim 1 , further comprising a pressure plate detection unit configured to detect opening and closing of the pressure plate, wherein the document size detection unit starts a document size detection operation in accordance with a detection content of the pressure plate detection unit. . The document reading apparatus according to claim 1 , wherein the blinking operation continuously performs lighting for a predetermined time at predetermined intervals . The document size detecting means detects a width of a document placed on the document table in the main scanning direction, and detects a width of the document placed on the document table in the sub-scanning direction. Sub-scanning document width detecting means,
The detection results of the main scanning document width detection means and the sub scanning document width detection means at the timing when the pressure plate is closed, and the main scanning document width detection means and the sub scanning document width detection when the pressure plate is closed. 4. The document reading apparatus according to claim 1, wherein the document size is detected using a detection result of the means. 5. 5. The document irradiating unit includes a fluorescent unit that converts coherent light guided from the coherent light emitting unit through the light guiding unit into visible light. 6. The document reading apparatus described.

Images