JP2005191737A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus for reducing the possibility of occurrence of a positional deviation in and adhesion of dust to a reflective reference plate for setting initial conditions of a reading optical system. <P>SOLUTION: A light source 31 for irradiating light on a specimen on a stage 10, a photoelectric conversion element for carrying out photoelectric conversion, an optical means for guiding the light, a carriage 35, and the reading reference plate 110 are respectively fitted to an apparatus frame 70, and the reading reference plate 110 is located in parallel with the stage 10 in a moving direction of a scanning unit A. An opening 12c for placing the specimen onto the stage 10 is formed on the apparatus frame 70, and a reading reference surface 110b of the reading reference plate 110 is positioned in the opening 12c of the apparatus frame 70 in a way that the reading reference surface 110b is located higher than a stage surface 12 and lower than the scanning unit A. Provision of a dustproof barrier (bracket) between the stage 10 and the reading reference plate 110 can more surely prevent the reading reference plate 110 from becoming dirty. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus that optically forms a planar image such as a sheet or a three-dimensional image such as the surface of a fluid on a photoelectric conversion element and electrically reads the image using this photoelectric conversion element. The present invention relates to an image reading apparatus for reading and analyzing the surface of a medium.

  In general, the propagation state of bacteria, microorganisms, etc. is analyzed by observing the substance cultured in a medium such as a liquid or a sheet with a microscope. Recently, this medium is electrically read by a photoelectric sensor such as a CCD image on a computer or the like. After analysis by processing equipment, inspection systems that store the data have come to be used. In an image reading apparatus used in such a system, the reading optical system must be different depending on whether the reading material is a culture solution contained in a container such as a petri dish or a culture solution impregnated in a sheet. In other words, when the reading material is a transparent or translucent material, light is irradiated from the back of the reading material, and the image is read by forming an image on the photoelectric sensor with this transmitted light. It is necessary to irradiate light from above the reading object and read the reflected light. When switching the light source according to such a reading object, it is common to set the initial conditions of the imaging optical system for each light source, and for this initial condition, for example, a white plate as a reference is read by a photoelectric conversion element. Calibration such as shading correction for correcting the bias of the light source and determination of a threshold reference value for digital conversion of acquired data are performed.

In the conventional general scanner apparatus, a white plate is attached to a part of a mounting table (platen) on which a reading object is placed. However, when the reading object is a three-dimensional object, this is not possible due to the focal length.
In view of this, an apparatus for reading a three-dimensional object, for example, Patent Document 1 proposes an apparatus in which a mounting table on which a three-dimensional object is set and a mounting table on which a sheet or the like is set are individually provided and scanned by one exposure unit. However, this publication does not disclose how to attach a calibration reading reference plate.
JP-A-7-140561

  When reading with bacteria and other three-dimensional objects set on the mounting table, it is necessary to consider that the reference plate for setting the initial conditions of the reading optical system does not adhere dust or the like. At the same time, it is necessary to consider that the reference plate does not cause a positional shift when the user sets the reading object on the mounting table. However, as is known in the art, when the reference plate is directly attached to the mounting table, there is a risk that the reference plate will be soiled or the mounting position may be shifted when setting the reading object, so that correct initial conditions can be set. Or the acquired image data cannot be processed correctly.

  Therefore, the present invention has been made based on the knowledge that it is possible to take measures such as dust prevention by providing a reading reference plate at a position different from the mounting table on which the reading object is set. An object of the present invention is to provide an image reading apparatus capable of always reading an accurate image with little risk of positional deviation or dust adhering to the reading reference plate for setting conditions.

  The present invention employs the following configuration in order to achieve the above-described problems. First, a mounting table having a mounting surface on which a reading object is mounted, a light source that irradiates light to the reading object on the mounting table, a photoelectric conversion element that photoelectrically converts light from the reading object, and the reading object Optical means for guiding light from the photoelectric conversion element to the photoelectric conversion element, a carriage on which at least a part of the optical means is mounted and moving along the mounting table, and a reading reference plate for acquiring a reading reference signal by the photoelectric conversion element; Are attached to the apparatus frame, and the reading reference plate is arranged in parallel with the mounting table in the moving direction of the scanning unit. The apparatus frame is provided with an opening on which the reading object is placed on the mounting table, and the reading reference surface of the reading reference plate is provided in the opening at a position higher than the mounting surface and lower than the scanning unit. Install on the frame. With this configuration, the reading reference surface is placed at a position different from the mounting surface of the mounting table, and the reading reference surface is soiled when dust from the reading material, particularly a reading material such as liquid contained in the container, is scattered or the container falls down. There is nothing to do. Further, by providing a dust-proof partition wall between the mounting table and the reading reference plate, it is possible to more reliably prevent the reference plate from being stained.

  Further, the mounting table is supported so as to be movable between a setting position for attaching / detaching a reading object to / from an opening of the apparatus frame and a scanning position for reading the reading object. As a result, there is no need for a work space for attaching and detaching the reading object above the mounting table, and the apparatus can be made smaller.

  It is necessary to project light from a light source on the reading object on the mounting table, and the light source is arranged above and below the mounting table as follows. First, a first light source that is disposed above the mounting table and irradiates the reading object with light, a second light source that is disposed below the mounting table and irradiates the reading object with light, and the light from the reading object is photoelectrically generated. A photoelectric conversion element to convert; an optical means for guiding light from the reading object to the photoelectric conversion element; a carriage on which at least a part of the optical means is mounted and moving along the mounting table; and a moving direction of the carriage And a device frame for supporting the mounting table and the carriage, the device frame being arranged in parallel with the mounting table and acquiring a reading reference signal by the photoelectric conversion element. An opening for receiving a reading object is provided above the mounting table, and the reading reference surface of the first reading reference plate is attached to the apparatus frame at a position higher than the mounting surface and lower than the scanning unit. In this case, the carriage is moved from the home position to the first position by arranging the first reading reference plate, the second reading reference plate, and the placement surface in the opening along the moving direction of the carriage. It is positioned on the reference plate or the second reference plate by controlling the amount of rotation of the drive motor or the like.

  Since the reading reference surface for obtaining the reading reference signal by the photoelectric conversion element is arranged at a position different from the mounting surface of the mounting table, the reading material such as dust from the reading material, particularly liquid stored in the container is scattered or the container. The reading reference surface is not soiled when the camera falls. Furthermore, by providing a dustproof partition between the mounting table and the reading reference plate, it is possible to more reliably prevent the reference plate from being stained, and when the reading object is placed on the mounting table, the reference surface It is possible to always read an accurate image without causing a positional shift by touching.

  The present invention will be described in detail below based on the preferred embodiments shown in the drawings. FIG. 1 shows the overall configuration of an image reading apparatus 100 embodying the present invention, FIG. 2 is a central longitudinal cross-sectional view thereof, and FIG. 3 is an explanatory view showing the main part of FIG. An image reading apparatus 100 in FIG. 1 includes a scanning unit A for optically reading a reading object in a housing D, a mounting table unit B for mounting the reading object, and a transmission light source unit C for irradiating the reading object with light. Configured. The housing D is composed of a box-shaped device frame 70, which is arranged in order of the transmission light source unit C, the mounting table unit B, and the scanning unit A from the bottom to the top of the device frame 70. The structure of each unit is as follows. is there.

[Structure of imaging optical system]
First, an imaging optical system that reads an image of a reading object with a photoelectric conversion unit will be described. The imaging optical system includes a line sensor 32 that photoelectrically converts light from a reading object, and an optical system 30 such as a mirror and a lens that guides light from the reading object to the line sensor 32, and is collected by the lens. The line sensor 32 is configured to obtain image data by electrically converting light from the read object. The light source shown in FIGS. 2 and 3 is a reflection light source 31 (first light source) that emits light from the surface (upper side of the apparatus) side of the reading object and a transmission that is irradiated from the back side (lower side of the apparatus) of the reading object that will be described later. A light source 50 (second light source) is provided. In the case where the reading material is an opaque (non-translucent) material such as a sheet original or a culture material impregnated in the sheet, the reflection light source 31 is irradiated onto the reading material, and the reflected light is irradiated by the optical system 30 to the line sensor 32. When the reading material is a bacterium cultured in a container such as a petri dish or a transparent (translucent) material such as a transparent film sheet, the transmission light source 50 is irradiated on the reading material, and the transmitted light is irradiated by the optical system 30. This is for guiding to the line sensor 32.

  Therefore, only the first light source (reflective light source) 31 is equipped when the reading object is limited to an opaque material, and only the second light source (transmission light source) 50 is provided when the reading object is limited to a transparent material. Just equip it. As the light source, a rod-shaped light source is used because the photoelectric conversion means described later is a line sensor, and any one of a halogen lamp, a fluorescent lamp, an LED array, and the like is used. The xenon lamp shown in the figure is adopted because it is inexpensive and easy to replace.

  As shown in FIG. 3, the optical system 30 includes an imaging lens 34 and a reflection mirror 33 that guides light to the imaging lens 34, and forms a generally known optical path. In the illustrated one, light from the reading object is guided to the imaging lens 34 by four mirrors 33a, 33b, 33c, and 33d in order to shorten the apparent length of the optical path. In this way, the optical system 30 can employ various configurations in which an image of the read object is formed on the line sensor 32 arranged at a predetermined position using a lens, a mirror, etc., for example, SELFOX A configuration in which light from a reading object is directly guided to the line sensor 32 by a lens array in which rod-shaped lenses such as lenses are arranged in a line may be used.

  The line sensor 32 uses a line-up of a plurality of photoelectric conversion elements such as a CCD (Charge Coupled Device), and scans the read object line-sequentially. The line sensor 32 includes a predetermined number of photoelectric conversion elements corresponding to the reading resolution, and the electromotive force generated by projecting the light of the reading object onto the line sensor 32 is sequentially transferred for each pixel to electrically transfer the image of the reading object. Get as data. Accordingly, the arrangement direction of the photoelectric conversion elements of the line sensor 32 is the main scanning direction.

  As shown in FIG. 4, the line sensor 32 is arranged in the XX direction shown in the figure, and a carriage described later is configured to move in the YY direction. In the illustrated example, the sub-scanning direction in the YY direction is set to be longer than the main scanning direction in the XX direction, and the carriage movement described later with respect to the main scanning direction length L1 described later. The length L2 is set long (L1> L2). Accordingly, when the carriage 35 moves from the home position indicated by the solid line in the direction of the arrow to the position indicated by the chain line, the reading object is read in a line sequential manner, and the effective reading area (shaded area in FIG. 4) is rectangular.

[Structure of scanning unit]
A configuration of the scanning unit A that includes the above-described line sensor 32 and scans along the reading object will be described. The scanning unit A includes a carriage 35 formed in an appropriate shape with little change over time and environmental change by molding such as synthetic resin, for example, and at least a part of the elements constituting the optical system 30 is mounted on the carriage 35. The light guided to the line sensor 32 by the movement of the carriage 35 is configured to scan the reading object.

  In this embodiment, the carriage 35 is provided with a reflection light source 31, an optical system 30 (mirrors 33a, 33b, 33c, 33d, an imaging lens 34), a line sensor 32, and the line sensor 32 as shown in FIG. A substrate 38 is mounted.

  As another method, although not shown, two carriages are provided so as to move along the image surface, a light source and a mirror for deflecting light from the reading object are mounted on one of the carriages, and the mirror is mounted on the other carriage. The mirror (one or more) that reflects the light from the line sensor in the direction of the line sensor is mounted. It is also possible to scan the image plane by fixing the imaging lens and the line sensor to the apparatus frame and moving the first carriage and the second carriage in synchronization.

  Further, as another scanning method, first and second carriages are provided, one of which is equipped with a light source and a mirror for deflecting light from the reading object, and the other is coupled with a mirror for deflecting light from this mirror. It is also possible to scan the image plane by mounting an image lens and a line sensor and moving the second carriage at half the moving speed of the first carriage. As described above, various methods are known for the optical system mounted on the carriage 35, and any of them can be adopted. Needless to say, the reflection light source 31 described above need not be provided when the reading object has an apparatus specification limited to a transparent material.

  The carriage 35 is movably attached to the apparatus frame 70. The carriage 35 shown in FIGS. 1 to 3 is slidably supported by a carriage guide member 36 (hereinafter referred to as a first guide member 36) provided in the apparatus frame 70. The first guide member 36 is composed of a pair of rod members 36a and 36b parallel to each other, and another rod member 36b (not shown) parallel to the rod member 36a shown in FIG. It is fixed to. A bearing 37a (see FIG. 2) integrally formed with the carriage 35 is fitted to the rod member 36a, and the rod member 36b is also fitted to the bearing of the carriage 35.

  Thus, the carriage 35 is supported so as to be movable in the left-right direction in FIG. 2 along the pair of rod members 36a, 36b. The first guide member 36 supports a part of the carriage 35 (for example, a part of the bottom surface) with one rod member that fits and supports the carriage 35 and the rail surface of the guide rail arranged in parallel with the rod member. You may do it. 38 is a substrate attached to the carriage 35. A line sensor 32 is attached to the substrate 38, and a heat sink (not shown) and a harness wire for transmitting an output signal of the line sensor 32 are attached to the substrate.

  Therefore, a drive belt 39 spanning a pair of pulleys 40a and 40b attached to the apparatus frame 70 is connected (fixed) to the carriage 35. One of the pulleys is connected to a drive motor 90 capable of forward / reverse rotation, which will be described later, and the carriage 35 reciprocates in the left-right direction in FIG. 2 along the first guide member 36 by forward / reverse rotation of the motor. A position sensor 41 (see FIG. 2) is provided in the movement path of the carriage 35, and the drive motor is controlled by a detection signal from this sensor. The illustrated one is attached to the apparatus frame 70 so that the sensor 41 detects a part of the carriage at the home position shown by the solid line in FIG.

[Structure of mounting table unit]
On the lower side of the carriage 35 (scanning unit A), the mounting table unit B is arranged with the following structure. The mounting table unit B is composed of a mounting table 10 (a mounting member) for setting a reading object and a holder member 11 (a mounting member for the mounting table) for supporting the mounting table 10, as shown in FIG. The holder member 11 is supported by the apparatus frame 70. At least two mounting tables 10 are prepared, each having a mounting surface 12 on which a reading object is mounted. One mounting table 10a (see FIG. 8) is configured to set a reading material such as a liquid stored in a container such as a petri dish, and the other mounting table 10b (see FIG. 11) sets a reading material such as a sheet. It consists of a structure. Each of the mounting tables 10a and 10b is formed with a height in the thickness direction so that a predetermined position in the height direction of the read object set coincides with a predetermined focus position corresponding to the resolution. The configuration of each mounting table 10 will be described later.

  As shown in FIG. 6, the holder member 11 is formed in a substantially box shape with a plate-like material as a frame, and is slidably supported by the apparatus frame 70. The holder member 11 has a box shape in which four sides are formed by a pair of side plates 13a and 13b facing each other in parallel with the movement direction (sub-scanning direction) of the carriage 35 and a pair of side plates 13c and 13d connecting the both side plates. Composed. A bottom plate 14 is attached to the bottom, and the side plates 13 and the bottom plate 14 are firmly connected by spot welding or the like. The side plates 13a and 13b are provided with rail members having a channel (C-shaped cross section) shape. In particular, the rail members 15a and 15b are attached with high precision so that the left and right are kept parallel to the moving direction of the carriage 35. Yes.

  Then, a part of the rail members 15a and 15b is bent, and the bent portions are inserted into the holder member 11 from the slits 200 formed in the side plates 13a and 13b, and the installation surface 19 is formed by the bent portions. At least one installation surface 19 is formed on each of the pair of rail members 15a and 15b. The illustrated installation surface 19 is provided at four locations as shown in FIG. 6A, and each installation surface 19 has a height direction. It is formed to be uniform. A mounting table 10 described later is mounted on the mounting surface 19. As described above, the installation surface 19 is formed integrally with the rail member 15, thereby reducing the number of parts and reducing the overlap tolerance (the tolerance obtained by adding the tolerances of each part), and the position of the reading object with respect to the focus position. Misalignment is reduced. The side plates 13a and 13b are provided with slide rollers 16a so as to slide on guide members (described later) of the apparatus frame 70. The bottom plate 14 is provided with an opening 18 for irradiating a reading object with light from a transmission light source, which will be described later, and the side plate 13c is provided with a handle 17 for operation.

  On the other hand, as shown in FIGS. 1 and 2, a guide roller 20 that rotates in contact with the rail members 15 a and 15 b is attached to the apparatus frame 70 at a position indicated by a chain line in FIG. 6. The guide member 21 (hereinafter referred to as a second guide member) is provided so as to be in contact with the guide roller 16 provided on the rail member 15 for guidance. Accordingly, the holder member 11 can move in the left-right direction in FIG. 2 along the pair of second guide members 21 provided on the apparatus frame 70, and the handle 17 is moved between the scanning position in FIG. 2 and the set position in FIG. It becomes possible to move. The second guide member 21 is attached in parallel with the first guide member 36 in the same direction.

  In addition, the height position of the mounting table 10 at the set position and the scanning position (reading position) is the same, and the mounting table 10 is on the same plane within the moving region between the setting position and the scanning position (reading position). It will be moving. Also, the carriage 35 is always at the same height in the movement region from the home position to the reading end position, and the carriage 35 is also moving on the same plane. The plane on which the mounting table 10 moves and the plane on which the carriage 35 moves are parallel to each other with a distance in the vertical direction.

  The holder member 11 reads a predetermined scanning position (the position shown in FIG. 2 or FIG. 3, the reading position) where the reading object placed on the mounting table 10 is scanned by the carriage 35 and the reading on the mounting table 10. The position is regulated as follows with respect to the set position (the position shown in FIG. 7) where the object is attached and detached. As shown in FIG. 7, the rail member 15 is formed with a stopper engaging portion 15c formed of a bent piece on at least one side, and a stopper 22 (for example, engaged with the bent piece on the apparatus frame 70 side). The second guide member 21 is provided with a relatively hard resin or the like. The stopper 22 is used to prevent the holder member 11 from falling off the housing D at the set position.

  Further, the image reading apparatus 100 includes holding means for positioning and holding the holder member 11 at the scanning position. This holding means includes a spring 23 (see FIGS. 1 and 2) formed of a leaf spring provided on the apparatus frame 70 side and an engagement groove 24 (see FIGS. 2 and 6) provided in the rail member 15 of the holder member 11. When the spring 23 is fitted into the engagement groove 24, the holder member 11 is held without rattling at the scanning position. The illustrated spring 23 and engagement groove 24 are provided on the left and right rail members 15a and 15b at the upper part and the four side parts, respectively, to prevent vertical rattle and lateral rattle, and at the same time by vibration or the like. The holder member 11 is held so as not to move from the scanning position to the set position side. The position of the holder member 11 at the scanning position is detected by a limit sensor 25 (see FIGS. 2 and 3) provided on the apparatus frame 70 side. If the holder member 11 is not correctly positioned at the scanning position, the sensor 25 The operation such as scanning of the carriage 35 is prohibited by this signal (details will be described later).

[Structure of mounting table]
The mounting table 10 detachably installed on the holder member is composed of at least two and has the following structure. Each mounting table 10 includes a mounting surface 12 on which a reading object is to be mounted, and is configured to have a shape suitable for the mounting surface 19 of the holder member 11. The mounting surface 12 has a predetermined reading position of the set reading object. The height is configured to match the focus position. 8 and 11 illustrate a mounting table 10a for setting a reading material stored in a container such as a liquid and a mounting table 10b for setting a reading material such as a sheet.

  First, the mounting table 10a for transparent reading material shown in FIG. 8 will be described. The mounting table 10a includes a mounting plate 1200 for mounting the petri dish 1 containing a liquid reading material such as bacteria, and a protrusion 26 (pin) that fits into an engaging hole 19a formed in the mounting surface 19 of the holder member 11. It has.

  The mounting plate 1200 is mounted on the opening 12c, and is composed of a transparent glass plate 12e and a diffusion plate 12b such as ground glass disposed on the lower surface of the glass plate 12e. Then, the light from the transmission light source 50 diffused by the diffusion plate 12b and transmitted through the glass plate 12e is irradiated to the reading object in the petri dish 1 placed on the surface of the glass plate 12e (mounting surface 12). Further, on the mounting surface 12, there are provided a position restricting member 12a for abutting and positioning a container such as the petri dish 1 and a biasing means 12d for pressing and holding the container (read material) against the restricting member 12a. .

  Further, as shown in FIG. 8B, the position regulating member 12a has two areas, a reading object placement area 1201 where the reading object is placed on the placement surface 12, and a transmission reference area 111 (transmission area). The transmission reference region 111 portion of the mounting plate 1200 is a reading reference plate (second reading reference plate). The transmission reference area 111 is an area for acquiring a reference signal required in a transmission reading mode to be described later, and the line sensor 32 reads light from the transmission light source 50 that has passed through the transmission reference area 111. Thus, it is possible to acquire a reference signal used for shading correction, gain adjustment, and the like.

  The container 1 such as a petri dish is also made of a transparent material. The mounting surface 12 of the mounting table 10a has a reading height in consideration of the installation height H1 (see FIG. 8a) of the container 1 and the height of the reading material accommodated therein (substantially central height of the liquid surface) H2. Is formed in a dimension that coincides with a predetermined focus position. That is, the focus position corresponding to the resolution is set at a height position (H1 + H2) from the installation surface 19 of the holder member 11. In this case, the height of the reading object is set in advance and determined as the apparatus specification.

  The protrusion 26 (pin) is provided at the bottom of the mounting table 10 a and is configured to fit into an engagement hole 19 a formed in the installation surface 19 of the holder member 11. Accordingly, the projection 26 and the engagement hole 19a constitute a positioning means, and the mounting table 10 is detachably attached to the holder member 11 and is installed at a predetermined position. The protrusions and the engagement holes are opposite to those shown in the figure, and the same positioning can be obtained by forming the engagement holes on the mounting table 10a side and the protrusions on the holder member 11 side. It is also possible to configure with mating step surfaces.

  Next, when the desired reading position (height) of the reading object stored in the container 1 is different from the predetermined focus position, correct image data cannot be read. In this case, the installation height position is adjusted by the height adjustment member 27 (adjustment member) shown in FIG. This height adjusting member is composed of a plate member having a thickness (adjusted height) H3, and several sheets having different adjusted heights H3 are prepared as appropriate. 27b shown in the figure is a hole that engages with the protrusion 26 of the mounting table 10a, and 27a is an opening that matches the opening 12c of the mounting table 10a.

  Therefore, as shown in FIG. 9, the mounting surface 12 is supported at a predetermined height H <b> 1 from the mounting surface 19 by the mounting table 10 a being engaged and supported by the mounting surface 19 of the holder member 11. Then, the container 1 is placed on the placement surface 12, and is positioned and held by the position regulating member 12a and the urging means 12d. When the mounting table 10a is attached to and removed from the holder member 11, the holder member 11 is moved to the set position shown in FIG.

  Further, the mounting surface 12 is constituted by a surface of a transparent glass plate 12e attached to the opening 12c, and a diffusion plate 12b such as ground glass is provided on the lower side of the glass plate 12e to transmit light from a transmission light source 50 described later. Light is irradiated from the transparent mounting surface 12 diffused by the diffusion plate 12b to the reading object of the container 1.

  Next, the configuration of the mounting table 10b when the reading material is an opaque material such as a sheet will be described with reference to FIG. Similar to the previous mounting table 10a, the mounting table 10b includes a protrusion 26 and a mounting plate 1200, and the mounting surface 12 on the upper surface of the mounting plate 1200 is formed with a predetermined height H4. 12 is configured to set the reading sheet on the sheet 12. The mounting plate 1200 is not necessarily formed of a transparent material, but is composed of a glass plate 12e and a diffusing plate 12b like the mounting table 10a so that a transparent sheet such as a film can be read. It is designed to be transparent. A pressing member 28 is provided on the mounting surface 12 so that the sheet on the mounting surface 12 does not move carelessly. The pressing member 28 is made of a plate of glass or other transparent material, and is attached to the mounting surface 12 by a hinge pin 28a so as to be freely opened and closed. The sheet is pressed against the mounting surface 12 by the weight of the pressing member 28 itself. To do.

  Similarly to the mounting table 10a, the mounting surface 12 is divided into two areas, a reading object mounting area 1201 on which a reading object is mounted and a transmission reference area 111 (transmission area). The 1200 transmission reference region 111 portion is a reference plate (second reading reference plate), and a reference signal in the transmission reading mode is acquired by reading light from the transmission light source 50 that has passed through the transmission reference region 111. .

  FIG. 12A shows a state where the mounting table 10b is mounted on the holder member 11 of the apparatus frame 70, and the correlation with the previous mounting table 10a will be described with reference to FIG.

  With respect to the focus position indicated by the one-dot chain line in FIG. 12B, the mounting table 10b is set so that the installation height H4 (mounting surface) coincides with this focus position. On the other hand, the mounting table 10a is set so that the installation height H1 of the mounting surface 12, the thickness of the bottom of a container such as a petri dish, and the height H2 considering the thickness of the reading object coincide with the focus position. The substantially central portion of the read object is set at a position in consideration of the height of (H1 + H2) and the depth of focus.

  In the illustrated apparatus, the depth of focus is about 3 mm, the thickness specification of the sheet-like reading material is less than about 1 mm, and the height specification of the liquid reading material is about 2 mm. Therefore, the height relationship shown in FIG. A favorable result is obtained with respect to variation. Further, as shown in the figure, a reflection reference surface 110 described later is also located at the focus position.

[Structure of transmission light source unit]
Next, the transmissive light source unit C disposed below the mounting table unit B will be described.
The apparatus frame 70 is provided with a transmissive light source 50 below the second guide member 21, and the light source 50 moves in synchronization with the same amount in the same direction as the above-described carriage 35 (hereinafter referred to as the first carriage 35). Configured to do. As shown in FIG. 2, the transmissive light source unit C includes two rod-like light sources 50a and 50b in the element array direction (main scanning direction) of the line sensor 32, and a second carriage 51 on which these light sources 50a and 50b are mounted. And has.

  The second carriage 51 is slidably supported by a pair of rod-shaped guide members 52a and 52b. Guide members 52 a and 52 b (hereinafter referred to as third guide members) made of the rod members are fixed to the apparatus frame 70 and arranged in parallel with the first guide member 36 of the first carriage 35.

  Similar to the first carriage 35, the second carriage 51 is fitted and supported by the third guide member on a bearing formed by synthetic resin molding (not shown) but integrally molded. Two light sources composed of xenon lamps are attached to the second carriage 51 so as to irradiate the mounting surface 12 of the mounting table unit B with light. The two light sources are provided in this way. This transmitted light source is attenuated by the diffusion plate 12b, and further irradiates the surface from the back side of the reading object. Therefore, smoothing with two light sources prevents unevenness in the light irradiated to the reading object.

  The second carriage 51 is also connected to a drive motor 90 described later so as to reciprocate between the position indicated by the solid line in FIG. 2 and the chain line position. 53a and 53b shown in the figure are a pair of pulleys attached to the apparatus frame 70, and a drive belt 54 is stretched over. A second carriage 51 is fixed to one portion of the drive belt 54. This pulley 53 a is connected to the drive motor 90. A glass plate 55 shown in the figure is attached to an opening that irradiates the mounting table 10 with light from the second light source 50.

[Housing structure]
Each of the above-mentioned units may be incorporated into individual frame frames, and the individual frame frames may be combined so that they are stacked in order from the bottom of the transmission light source unit, the mounting table unit, and the scanning unit. The structure is adopted.

  FIG. 13 shows a frame structure of the apparatus frame 70. The apparatus frame 70 includes a first frame frame 71 and a second frame frame 72 which are different from each other. The first frame frame 71 includes the transmission light source unit C described above. The mounting table unit B and the scanning unit A (first carriage 35) are incorporated in the second frame frame assembly 72.

  The first frame frame 71 is fixed with the third guide members 52a and 52b of the transmissive light source unit C. The first frame 71 is formed in a box shape with four side walls 73a, 73b, 73c, 73d and a bottom plate 74a, and both ends of the third guide members 52a, 52b are supported by a pair of opposing side walls 73c, 73d. Has been. 74b in the figure is an upper plate to which a glass plate 55 is attached, and the intrusion of dust is prevented by separating the transmission light source 50 and the opening 156 in which the mounting table unit B disposed above is separated by the upper plate 74b. It is preventing.

  On the other hand, the second frame framework 72 is configured in a box shape in which the four sides are firmly framed by side plates 75a, 75b, 75c, and 75d. A pair of opposing side plates 75a and 75b (second side walls) are arranged (substantially in parallel) along the sub-scanning direction of the first carriage 35 incorporated therein, and the other opposing side plates 75c and 75d (first side) are arranged. The side walls are arranged along the main scanning direction (substantially in parallel). Therefore, the side plates 75a and 75b (second side wall) are positioned in the longitudinal direction and the side plates 75c and 75d (first side wall) are positioned in the short direction (the second side wall is set longer than the first side wall). The second guide member 21 of the mounting unit B is attached to the side plates 75a and 75b, and the first guide member 36 of the first carriage 35 is attached to the side plates 75c and 75d. The second guide member 21 is attached substantially in parallel with the side plates 75a and 75b (second side walls).

  That is, both ends of the pair of rod members 36a and 36b constituting the first guide member 36 are fixed to the opposing side plates 75c and 75d in the short direction, and the second guide member is fixed to the opposing side plates 75a and 75b in the longitudinal direction. The rail member which comprises 21 is attached. The first guide member 36 and the second guide member 21 are attached to the second frame frame 72, and the third guide members 52a and 52b are attached to the first frame frame 71 in the first way. This is for maintaining the positional relationship between the carriage 35 and the mounting table 10 with high accuracy. On the other hand, the transmission light source 50 irradiates the reading object with the light smoothed by the diffusion plate 12b, so that a very accurate positional accuracy is required. It is because it is not done.

  Therefore, in the manufacturing stage of such an apparatus, the mounting table unit B and the first carriage 35 are accurately incorporated in the second frame framework 72, and the transmissive light source unit C is incorporated in the first frame framework 71 separately from this manufacturing process. If the second frame frame 72 is placed over the first frame frame 71 and the second frame frame 72 is fixed to the first frame frame 71 by screwing, the device is relatively inexpensive and easy. Can be manufactured. Further, the first and second guide members are assembled to the second frame frame 72 as described above, and the glass plate 76 shown in FIG. 2 is next between the first carriage 35 and the mounting table unit B. It is assembled like this.

  As shown in FIG. 2, a partition plate 77 (cover member) is fixed to the side plate constituting the second frame framework 72, and the box-shaped frame framework 72 is accommodated in an accommodation space (movement area) 1300 of the first carriage 35. And the opening 156 in which the mounting table unit B is accommodated. This is to prevent contamination of the optical system 30 and the line sensor 32 due to scattering of liquid reading materials such as external dust and bacteria in the first carriage 35. A glass plate 76 is attached to the partition plate 77. Therefore, the housing of the apparatus has the first carriage housing space, the mounting table housing space, and the transmissive unit housing space by the first and second frame frames. The glass plate 76 of the partition plate 77 and the glass plate 55 of the transmissive light source unit C. It will be configured to be partitioned by.

  As shown in FIGS. 2 and 3, the opening 156 is partitioned by the partition plate 77 and the upper plate 74b described above, and the mounting table 10a or the holder member 11 to which the mounting table 10b is attached is accommodated in this opening. . Further, a bracket 113 to which a later-described reflection reference plate 110 is attached is attached to the partition plate 77 and protrudes from the opening 156. The reflection reference plate 110 and the reflection reference surface 110b are located in the opening 156.

[Structure of reference surface for reflection]
A reflection reference plate for acquiring a reference signal used when reading in a reflection reading mode to be described later is incorporated in the apparatus as follows.
The reflection reference plate 110 (first reading reference plate) is disposed in a position different from the mounting table 10 on the apparatus frame 70 (second frame frame 72 in the illustrated case).

The positional relationship of each member in a state where the holder member 11 to which the mounting table 10b is attached is set at the scanning position will be described with reference to FIG.
In FIG. 14, the direction indicated by the arrows X1-X2 is the direction in which the first carriage 35 moves, X1 at the left end of the figure is the carriage 35 home position, X2 is the reading end position, and X3 is the reading start position. The reflection reference plate 110, the transmission reference area 111, and the reading object placement area 1201 are arranged in this order from the home position X1 of the carriage 35 toward the reading end position X2.

Further, as shown in FIG. 3, the reflection reference plate 110 is disposed on a bracket 113 having a U-shaped cross section, and the bracket 113 is attached to a partition plate 77 attached to the apparatus frame 70.
The reflection reference plate 110 is made of a white film material (opaque material), and the film material is attached to the bottom surface of the glass plate 1100, and the glass plate 1100 is fixed to the bottom portion of the bracket 113. The bracket 113 is formed of a channel member and is disposed below the glass plate 76 attached to the partition plate 77.

  As shown in FIG. 12, the reflection reference surface 110b on the upper surface (front surface) of the reflection reference plate 110 is located at a predetermined focus position indicated by a two-dot chain line and is higher than the placement surface 12 of the placement table 10a. Is located. Further, as shown in FIG. 3, the reflection reference surface 110 b is located below the carriage 35.

  In this embodiment, the reflection reference plate 110 is formed on the bottom surface of the glass plate 1100. This is because, in the reflection mode (described later) for reading the reflected light from the first light source 31, most of the reading material is a sheet. The sheet mounting table 10b includes the pressing member 28 made of glass as described above, and reading is performed by mounting the pressing member 28 on the sheet. The reflection reference plate 110 is formed on the bottom surface of the glass plate 1100 in order to read the reflection reference plate 110 under the same conditions as possible. Therefore, when the pressing member 28 is not provided, the white film constituting the reference surface 110 for reflection only needs to be attached to the bottom surface of the bracket 113.

  Therefore, the reflection reference plate 110 (reflection reference surface 110b) is surrounded by the bracket 113 so that dust does not enter, and in particular, the side wall 113a of the bracket 113 serves as a partition wall between the mounting surface 12 and a reading object such as a liquid. Is prevented from scattering and entering. Further, since the bracket 113 is supported by being suspended downward from the partition plate 77 of the apparatus frame 70 on which the first carriage 35 is disposed, the side portion of the apparatus frame 70 is a moving mechanism of the mounting table 10, for example, the first guide member 36. It is used as a space for layout. Therefore, the device is further miniaturized.

[Different Embodiments of Housing and Reading Reference Plate]
An embodiment different from the structure of the housing and the reading reference plate shown in FIGS. 1 to 13 described above will be described with reference to FIG. In FIG. 17, an opening 156 as shown in the figure is formed between the lower housing 151 and the upper housing 150, and the reading object is attached to and detached from the mounting table 162 attached to the lower housing 151 through the opening 156. The embodiment made into this is shown. A mounting table 162 is attached to the first frame frame 151a constituting the lower housing 151 at a position facing the opening 156. The second carriage 161 reciprocates in the first frame frame 151a in the same manner as described above. It is attached to the rod-shaped guide member 164 so as to be movable. A second light source 158 is mounted on the second carriage 161, and the structure thereof is the same as described above. A first carriage 159 is attached to a first guide member 163 so as to be able to reciprocate in the second frame framework 150a constituting the upper housing 150. On the first carriage 159, an optical system 165 including a mirror and a lens is mounted with the same structure as described above. A first light source 166 and a photoelectric conversion element (line sensor) 167 are mounted on the first carriage 159. The first and second carriages are configured to reciprocate in the left-right direction in FIG.

  Therefore, a mounting table 162, a first reading reference plate 152, and a second reading reference plate 154 are attached to the first frame framework 151a as follows. The mounting table 162 is formed of a glass member and is fixed to the first frame framework 151a. A diffusion plate 169 is disposed on the back surface of the glass member facing the second light source 158. One end of the mounting surface constituted by the surface of the glass member forms a transmission reference area 152, and the transmission reference area 152 portion of the mounting table 162 is a second reading reference plate 154. Then, the reference signal can be acquired by reading the light from the second light source 158 transmitted through the transmission reference region 152 by the line sensor 167. A first reading reference plate 152 is attached to the first frame 151a in parallel with the mounting table 162. The reference plate is divided by a mounting table 162 and a partition wall 170, and is made of white opaque film material made of transparent glass. Therefore, the surface of the white film becomes the first reading reference surface 153, and the light from the first light source 166 reflected by the white film is read by the line sensor 32, whereby the reference signal can be acquired. In addition, 171 in the figure is a glass plate that separates the first carriage 159 and the mounting table 162.

[Structure of drive mechanism]
The first carriage 35 incorporating the optical system 30 and the line sensor 32 and the second carriage 51 of the transmissive light source unit C are connected to a single drive motor 90. The drive motor 90 is composed of a stepping motor capable of forward and reverse rotation, and is attached to the second frame frame 72 of the apparatus frame 70 as shown in FIG. The motor 90 is fixed to a motor bracket 91, and a transmission pulley 92 is attached to the motor bracket 91, and the transmission pulley 92 and a rotation shaft of the motor are connected by a transmission belt 93. The transmission pulley 92 and the pulley 40 a of the drive belt 39 are connected by a transmission belt 96.

  The motor bracket 91 is supported on the side wall 73a of the apparatus frame 70 by a long groove 94 so as to be movable in the left-right direction in FIG. 5, and the bracket 91 is urged to the right in FIG. 5 by a spring 95 having one end fixed to the side wall 73a. . This is for adjusting the tension of the transmission belts 93 and 96. The pulley 97 attached coaxially to the pulley 40a to which the rotation of the drive motor 90 is thus transmitted and the pulley 53a of the second carriage 51 are connected by a transmission belt 98. A tension roller 99 shown in the figure adjusts the tension of the transmission belt 98 by a biasing spring. Therefore, the first carriage 35 and the second carriage 51 reciprocate simultaneously in the same direction (sub-scanning direction) by the same amount by forward and reverse rotation of the drive motor 90.

[Device control structure]
Control of the above apparatus will be described with reference to FIG.
The reading material on the mounting table 10 is subjected to processing such as digitization on the image data read by the line sensor 32, and then output to an external device such as a computer or a printer. Then, the computer performs an analysis based on the acquired image data, or the printer executes the target process by printing the acquired image data on a sheet.

  In view of this, the above-described apparatus has a built-in control board. In the illustrated apparatus, the control CPU 120, the image data processing IC 121a, and the data transfer IC 121b are incorporated in the control board attached to the side plate 75b of the apparatus frame 70. A shading correction SRAM 122, an inter-line correction SRAM 123, a gamma correction SRAM 124, and the like are connected to the image processing IC 121a. A buffer SDRAM 125a for transmitting data to an external device and an interface 125b are connected to the data transfer IC 121b. A control circuit 128 of the drive motor 90 is connected to the control CPU 120. At the same time, the position sensor 41 of the first carriage 35 and the limit sensor 25 of the mounting table unit B are connected to the control CPU 120 and the respective detection signals are transmitted. Is done. 126 in the figure is a control panel for turning on the apparatus power and setting various image reading conditions. At the same time, the control CPU 120 is provided with a command line for setting image reading conditions from an external device.

  Each of the first and second light sources is connected to a power source via an inverter, and is simultaneously connected to the control CPU 120. The CPU 120 supplies power to the reflected light source 31 (first light source) and the transmissive light source 50 (first light source). ON / OFF control of power supply to 2 light sources). The control CPU 120 is connected to the control circuit of the line sensor 32 so as to transmit a synchronization signal (clock signal) to the line sensor 32 and sequentially transfer the electromotive force of each component. The electric signal output from the line sensor 32 is converted into a digital signal by the A / D converter 127 and then transmitted to the image data processing IC 121a.

  The control circuit 128 of the drive motor 90 is provided with a pulse generator 91a for supplying a pulse voltage to the motor (stepping motor) and a counter 91b for counting the pulses, and the counter 91b is connected to the control CPU 120. Therefore, the control CPU 120 controls the position of the first carriage 35 and the second carriage 51 by controlling the rotation amount of the drive motor 90 by the number of pulses of the supply voltage. A limit sensor 25 for detecting the holder member 11 is connected to the control CPU 120 to monitor whether or not the mounting table 10 is located at a predetermined scanning (reading) position. Similarly, the first carriage 35 is connected to the control CPU 120. It can be determined by a signal from the position sensor 41 whether or not it is in the home position.

[Explanation of device operation]
The operation procedure of the image reading apparatus of the present invention will be described with reference to FIGS. 16 (a) and 16 (b).
This apparatus sets the scanning (moving) speed of the first carriage 35 and the second carriage 51 synchronized with the first carriage 35 according to the operation mode, for example, the reading conditions such as the image type such as color, black and white, and gray scale and the resolution. ing. The reading conditions may be set by either the external device or the control panel. The external device may be configured to set (trimming setting) the reading range of the reading object. In this case, the reading object is pre-scanned once and the range is specified (trimming) by a display device such as a CRT. Next, the set range is read under the set conditions.

  FIG. 16A is a flowchart showing an initial operation of the apparatus, and FIG. 16B is a flowchart showing an image reading operation. In FIG. 16A, when the apparatus power is turned on, the following initial operation is executed. When the apparatus power is turned on by operating the control panel (ST1), the control CPU 120 monitors the state of the limit sensor 25 of the holder member 11 to determine whether or not it is located at the scanning position (ST2). When the holder member 11 (mounting table 10) is not positioned at a predetermined scanning position (no in the drawing), a warning is displayed such as a warning display on the control panel, and the process waits until the limit sensor 25 is turned on. On the other hand, when the holder member 11 (mounting table 10) is located at a predetermined scanning position (yes in the drawing), the control CPU 120 starts an initial operation. This initial operation is started by determining whether or not the first carriage 35 is at the home position based on a signal from the position sensor 41. If not, the CPU 120 rotates the drive motor 90 leftward in FIG. The first carriage 35 is positioned at the home position.

  Next, the control CPU 120 sends an activation signal to the drive motor 90, moves the first carriage 35 to a predetermined position on the reflection reference surface 110b (ST3), and stops the motor 90. The predetermined position on the reflection reference surface 110b is a position where the light from the first light source 31 is not blocked by the bracket 113 supporting the reflection reference surface 110b, and is approximately the center of the reflection reference surface 110b in the sub-scanning direction. . The amount of movement of the first carriage 35 is controlled by counting the number of pulses of the pulse voltage of the drive motor with the counter. Therefore, after the first carriage 35 has moved to a predetermined position on the reflection reference surface 110b, the control CPU 120 takes in the output data of the line sensor 32 in a state where the first and second light sources 31 and 50 are turned off to obtain an offset value. Offset adjustment (ST4) is performed.

  The offset adjustment is an adjustment value (offset value) such that the voltage (dark voltage) for each pixel output from each photoelectric conversion element when the light source is turned off becomes the minimum input voltage of the A / D converter 127. Is what you want. Next, the control CPU 120 issues an instruction signal (ST5) for turning on the lamp of the reflection light source 31 (first light source) in a state where the line sensor 32 is located at a predetermined position on the reflection reference surface 110b. In the state, the above gain adjustment is executed (ST5). In the gain adjustment, the voltage for each pixel output from each photoelectric conversion element based on the reflected light from the reflection reference surface 110b when the light source is turned on becomes a value close to the maximum input voltage of the A / D converter. Such an adjustment value (gain value) is obtained. The control CPU 120 repeats the offset adjustment and the gain adjustment as necessary. When the appropriate offset value and gain value are obtained, both adjustments are finished and the reflected light source 31 is turned off (ST6).

  Next, the CPU 120 activates the drive motor 90 to move the first carriage 35 to a predetermined position on the transmission reference area 111 (ST7). Therefore, the control CPU 120 stops the first carriage 35 at this position, acquires the output data of the line sensor 32 with the first and second light sources turned off, and executes offset adjustment (ST8). Thereafter, the control CPU turns on the lamp of the transmissive light source (second light source), reads the transmissive reference area 111 for one line by the line sensor 32, and performs gain adjustment (ST9). At this time, the first light source 31 (reflective light source) is turned off. The control CPU 120 repeats offset adjustment and gain adjustment as necessary. When the appropriate offset value and gain value are obtained, both adjustments are completed and the transmissive light source 50 is turned off (ST10). Each offset value and gain value for the reflection reading mode and the transmission reading mode acquired in the above step are stored in the memory. Next, the control CPU 120 issues a return support signal to the drive motor 90, and upon receiving this signal, the drive motor 90 rotates in the reverse direction to return the first carriage 35 to the home position (ST11). Therefore, after the first carriage 35 is detected by the position sensor 41 and a predetermined pulse has elapsed, the drive motor 90 stops (ST12) and the initial operation is ended (ST13).

  Next, the reading operation will be described with reference to FIG. First, in this apparatus, the user selects one of the plurality of mounting tables according to the type of the reading object, and attaches the selected mounting table 10 to the holder member 11. This attachment is performed by pulling the holder member 11 from the apparatus frame 70 to the set position (state shown in FIG. 7). Further, the user places and sets the reading object on the placement surface 12 at the set position, and moves the placed placement table 10 together with the holder member 11 to the scanning position.

  Therefore, the user uses an external device such as a computer (1) image type (color or monochrome) (2) resolution (600/300 DPI in the figure) (3) light source selection (reflection light source or transmission light source) (4 ) Input reading conditions such as reading range setting (ST20). When the user sets this reading condition and turns on the start switch, the control CPU 120 monitors the state of the limit sensor 25 of the mounting table unit B, and when the mounting table 10 is not positioned at the scanning position (sensor OFF signal). The system waits until the limit sensor 25 is turned on (ST21). On the other hand, when the limit sensor 25 is in the ON state, the CPU 120 executes black shading processing (ST22). In the black shading process, an image signal is acquired from the line sensor 32 with all light sources turned off at the home position, a reference value for shading correction is set, and the set value is stored in the memory.

  Next, the control CPU 120 determines whether the light source used in the initial condition setting is the reflection light source 31 or the transmission light source 50 (whether it is the reflection reading mode or the transmission reading mode) (ST23), and turns on the lamp of the designated light source (ST23). ST24). Thereafter, the control CPU issues a start instruction signal to the drive motor 90 and advances the first carriage 35. As described above, the movement of the first carriage 35 advances in the order of the reflection reference surface 110b, the transmission reference region 111, and then the reading region (reading object placement region 1201). Therefore, the control CPU 120 performs white shading processing (when the first carriage 35 advances to the position of the reflection reference surface 110b when the light source to be used is selected as the reflection light source 31 and the transmission reference region 111 when the light source 50 is used. ST26) is executed. In this process, the line sensor 32 is driven while the light source is turned on to acquire data, and a correction value for correcting the variation in light quantity by this image processing is stored in the memory. When the first carriage 35 reaches a predetermined reading start position, the control CPU 120 sequentially reads an image of the read object with the line sensor 32 (ST27).

  Therefore, the control CPU 120 sequentially transfers the image signal to a memory such as a shift register while reading the image for each line, and the analog signal output from the line sensor 32 is converted into a digital signal by the A / D converter 127. After the image processing IC performs processing such as gain adjustment and offset adjustment using the gain value / offset value described above, shading correction, interline correction, gamma correction, dither correction, and the like, externally as image data via the interface Transfer to device.

  Next, the control CPU 120 determines whether or not the number of lines corresponding to the reading area designated by the initial condition setting has been reached (ST28). If the set number of lines has not been reached, reading of the next rank line is continued. The number of lines is determined by counting the number of main scans with a counter and comparing the read area set in consideration of the resolution with a reference value converted into the number of lines. When the number of read lines matches the predetermined number of lines, the control CPU 120 turns off the light source 31 or 50, reverses the drive motor 90, returns the first carriage 35 to the home position, and ends a series of read operations. . When the holder member 11 is moved from the scanning position during reading and the limit sensor 25 is detected to be off, the CPU 120 immediately turns off the light source and returns the first carriage 35 to the home position. Furthermore, the image data acquired so far is discarded.

1 is a perspective view showing an overall configuration of an image reading apparatus embodying the present invention. Explanatory drawing which shows the center longitudinal cross-section of the apparatus of FIG. FIG. 3 is a main part explanatory view showing configurations of a scanning unit and a transmissive light source unit in FIG. 2. FIG. 2 is a main part explanatory view showing a mounting table structure of the apparatus of FIG. 1. The side view which shows the drive mechanism of the apparatus of FIG. The holder member which supports the mounting base of the apparatus of FIG. 1 is shown, (a) is a top view, (b) is a side view. The state figure which moved the holder member in the apparatus of FIG. 1 to the set position. The structure of a mounting base is shown, (a) is a longitudinal cross-sectional view, (b) is a top view. Explanatory drawing of the state which attached the mounting base of FIG. 8 to the holder member. The height adjustment member of a mounting base is shown, (a) is the top view, (b) is a longitudinal cross-sectional view. FIG. 9 is a longitudinal sectional view illustrating a configuration of a mounting table different from FIG. 8. (A) is explanatory drawing of the state which attached the mounting base of FIG. 11 to the holder member, (b) is explanatory drawing of the mounting state of the mounting base of FIG. 8 and FIG. The disassembled perspective view which shows the frame structure of the apparatus of FIG. Explanatory drawing which shows the positional relationship of each area | region. The block diagram which shows the control circuit of the apparatus of FIG. FIGS. 1A and 1B are flowcharts showing the operation state of the apparatus of FIG. 1, in which FIG. 1A shows a procedure of initialization operation, and FIG. Explanatory drawing which shows the frame structure different from the frame structure of FIG.

Explanation of symbols

A scanning unit B mounting table unit C transmission light source unit D housing 1 Petri dish (container)
10a, 10b Mounting table 11 Holder member 12 Mounting surface 12a Position regulating member 12b Diffusion plate 14 Side plate 15 Guide member 15a, 15b Rail member 15c Stopper engaging portion 19 Installation surface 20 Guide roller 21 Guide member (second guide member)
25 Limit sensor 27 Height adjustment member 30 Optical system 31 Reflection light source (first light source)
32 Line sensor 33 Mirror 34 Imaging lens 35 Carriage (first carriage)
36 Carriage guide member (first guide member)
36a Rod member 36b Rod member 42 Image processing circuit 50 Transmitted light source (second light source)
50a, 50b Rod-shaped light source 51 Second carriage 52a, 52b Rod-shaped guide member (third guide member)
70 device frame 71 first frame frame 72 second frame frame 73a, 73b, 73c, 73d side wall 75a, 75b, 75c, 75d side plate 76 glass plate 77 partition plate 90 drive motor 100 image reading device 110 reading reference plate (first 1 reference plate)
110b Reflection reference plate 111 Transmission reference region 113 Bracket 128 Control circuit 1100 Glass plate 1200 Mounting plate (second reference plate)
1201 Reading object placement area

Claims (13)

A mounting table having a mounting surface on which a reading object is mounted;
A light source for irradiating the reading object on the mounting table with light;
A photoelectric conversion element that photoelectrically converts light from the reading object;
Optical means for guiding light from the reading object to the photoelectric conversion element;
A carriage carrying at least a part of the optical means and moving along the mounting table;
A reading reference plane that is arranged in parallel with the mounting table in the movement direction of the carriage and acquires a reading reference signal by the photoelectric conversion element;
An apparatus frame for supporting the mounting table and the carriage;
The apparatus frame is provided with an opening for placing the reading object on the mounting table and accommodated therein, and the reading reference surface is disposed in the opening and supported by the apparatus frame at a position higher than the mounting surface and lower than the carriage. An image reading apparatus.   The apparatus frame includes an upper housing that houses the carriage and a lower housing that supports the mounting table, and the reading reference surface is attached to a position protruding from the upper housing to the opening of the apparatus frame. The image reading apparatus according to claim 1.   The image reading apparatus according to claim 2, wherein the upper housing includes a transparent cover member that covers a range of movement of the carriage between the carriage and the mounting table.   4. The image reading apparatus according to claim 1, wherein the opening of the apparatus frame forms an operation space for placing a reading object on the mounting table.   4. The image according to claim 1, wherein the mounting table is supported by an opening of the apparatus frame so as to be movable between a set position for attaching / detaching a reading object and a scanning position for reading the reading object. Reader.   6. The image reading apparatus according to claim 5, wherein the mounting table is detachably supported by a holder member, and the holder member is slidably supported by a guide rail provided in the apparatus frame.   The image forming apparatus according to claim 5, wherein the reading reference plate is fixed at a position different from the mounting table of the opening of the apparatus frame.   8. The image reading apparatus according to claim 1, wherein the apparatus frame has a dust-proof partition wall between the mounting table and the reading reference plate. A mounting table having a mounting surface on which a reading object is mounted;
A first light source disposed above the mounting table for irradiating the reading object with light; a second light source disposed under the mounting table for irradiating the reading object with light;
A carriage which is movably arranged along the mounting table and forms an image of light from the reading object on a photoelectric conversion element;
A first and second reading reference plate arranged in parallel with the mounting table in the moving direction of the carriage and acquiring a reading reference signal by the photoelectric conversion element;
An apparatus frame for supporting the mounting table and the carriage;
The first reading reference plate is provided with a reference surface that reflects light from the first light source,
The second reading reference plate is provided with a transmission region that transmits light from the second light source,
The device frame is provided with an opening for placing the reading material on the mounting table and storing it,
The image reading apparatus, wherein the first reading reference plate is disposed in the opening, and the reference surface is supported by the apparatus frame at a position higher than the mounting surface and lower than the carriage.   10. The image according to claim 9, wherein the first reading reference plate, the second reading reference plate, and a placement surface are arranged in the opening in the moving direction of the carriage. Reader.   The mounting table is supported by an opening of the apparatus frame so as to be movable between a setting position for attaching / detaching a reading object and a scanning position for reading the reading object, and the second reading reference plate is attached to the mounting table. The image reading apparatus according to claim 9.   The carriage includes a drive motor, and is configured to be movable between a home position and the mounting surface. The drive motor is attached to the apparatus frame in the vicinity of the home position, and the carriage includes the home position, the carriage, The image reading apparatus according to claim 9, wherein the image reading apparatus moves in the order of the first reading reference plate, the second reading reference plate, and the placement surface.   The mounting table is supported by the opening of the apparatus frame so as to be movable between a set position for attaching / detaching a reading object and a scanning position for reading the reading object, and the scanning position is arranged on the home position side of the carriage. The image reading apparatus according to claim 12, wherein

Images