Patent Description:
The inkjet printing apparatus which prints images on a printing medium by dispensing ink droplets thereto is subject to various instances of trouble. These instances include trouble due to dispensation such as missing nozzles, horizontal jump of ink droplets, and dispensation at unspecified times of ink droplets (what is called dripping), trouble due to transportation of the printing medium such as skew, meandering, wrinkles, and so on, trouble of ink flow due to an insufficient drying of ink droplets, and contamination by re-adhesion due to contamination of rollers accompanying the ink flow. So, the inspecting apparatus is used to inspect printed images.

Conventionally, this type of apparatus includes a light source, and a reading sensor. See <CIT> (<FIG>), for example. The light source and reading sensor are arranged to face the same surface of a printing medium. The light emitted from the light source is reflected by the printing medium to fall on the reading sensor.

With such construction, the printing medium, when transparent, allows reflected light to pass through a transparent area. It is therefore difficult to distinguish between an image portion printed in black ink and a transparent portion. As a result, there arises a problem that an accurate inspection cannot be performed when the printing medium is transparent.

Then, there is an apparatus having a photographic device, a first light emitter, and a second light emitter. See <CIT> (<FIG>), for example. The first light emitter is disposed opposite the photographic device across the printing medium. The second light emitter is disposed at the same side as the photographic device. Consequently, transmitted light from the first light emitter falls on the photographic device. From the second light emitter, reflected light falls on the photographic device. This enables an accurate inspection even when the printing medium is transparent. A further prior art document is <CIT>.

However, the conventional example with such construction has the following problem.

The conventional apparatus has transport rollers arranged upstream and downstream of the photographic device. Especially when the outer circumferential surfaces of the transport rollers are silver-colored, strong reflections occur from the transport rollers. Consequently, the lights reflected from the transport rollers may cause noise for the photographic device to impair precise inspection. Note that this problem may arise even when the construction includes no second light emitter as light source of reflected light.

This invention has been made having regard to the state of the art noted above, and its object is to provide an inspecting apparatus and an inkjet printing apparatus having the inspecting apparatus, which can perform an accurate inspection by suppressing noise due to lights reflected from transport rollers.

This object is achieved by the subject-matters of independent claims <NUM> and <NUM>. Preferred embodiments are subject-matters of the dependent claims.

This invention provides an inspecting apparatus for reading print images printed on a transparent printing medium and inspecting printing states, the apparatus comprising amongst others a first transport roller for transporting the transparent printing medium; a second transport roller spaced from the first transport roller, and disposed downstream in a transport direction, for transporting the transparent printing medium; a photographing device disposed between the first transport roller and the second transport roller, and opposed to one surface of the transparent printing medium, for photographing the print images located in an inspection area set between the first transport roller and the second transport roller; and a light emitting device for emitting light for the photographing device to photograph the print images located in the inspection area; wherein the first transport roller and the second transport roller have outer circumferential surfaces thereof each with a light absorbing member for absorbing the light from the light emitting device.

According to this invention, the first transport roller and second transport roller have outer circumferential surfaces thereof each with a light absorbing member for absorbing the light from the light emitting device. This construction can inhibit the light emitted from the light emitting device from reflecting from the first transport roller and second transport roller. As a result, noise due to the light reflected from the first transport roller and second transport roller can be suppressed. Thus, an accurate inspection can be performed.

In this invention, it is preferred that the light absorbing member is a black tape provided with antireflection treatment.

The outer circumferential surfaces of the first transport roller and second transport roller are formed of black tapes provided with antireflection treatment (e.g. pearskin treatment). This construction can be realized at low cost. Further, since the black tapes are simply wound, this measure is easily applicable also to existing apparatus.

In this invention, it is preferred that the light absorbing member is a needlelike construction with numerous recesses and numerous projections, and with a black coat.

The outer circumferential surfaces of the first transport roller and second transport roller are each formed of a needlelike construction with numerous recesses and numerous projections, and with a black coat. This assures excellent durability, which can maintain the effect over a long period of time.

For the purpose of illustrating the invention, there are shown in the drawings several forms which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangement and instrumentalities shown.

Various embodiments of this invention in an inkjet printing apparatus having inspecting devices will be described hereinafter.

Embodiment <NUM> of this invention will be described hereinafter with reference to the drawings.

<FIG> is an outline schematic view showing an entire inkjet printing apparatus according the embodiments.

An inkjet printing apparatus <NUM> includes a sheet feeder <NUM>, a coating unit <NUM>, a printing unit <NUM>, a main drying unit <NUM>, and a takeup roller <NUM>. <FIG> shows a transport direction X extending from right to left therein, with the left side being downstream, and the right side upstream. Where convenient, the directions may be expressed with signs attached, e.g. +X direction indicating leftward, and -X direction indicating rightward, with reference to a certain position. The direction of depth from the plane of the drawing in <FIG> is regarded as transverse direction Y. The up-down direction in <FIG> is height direction Z. The above-mentioned sheet feeder <NUM>, coating unit <NUM>, printing unit <NUM>, main drying unit <NUM>, and takeup roller <NUM> are arranged in the stated order downstream in the transport direction X.

The sheet feeder <NUM> supplies the coating unit <NUM> with soft wrapping film WF to be printed. The soft wrapping film WF in this embodiment is a transparent film, for example. The sheet feeder <NUM> holds a roll of soft wrapping film WF to be rotatable about a horizontal axis. The sheet feeder <NUM> unwinds the soft wrapping film WF, with a printing surface turned upward, into the coating unit <NUM>. The material of soft wrapping film WF is a hydrophobic base material, for example, with a low absorbency for water-based ink. The soft wrapping film WF may be plastic film such as polypropylene resin, vinyl chloride resin, and polyimide resin, for example.

The soft wrapping film WF noted above corresponds to the "transparent printing medium" in this invention.

The coating unit <NUM> coats the soft wrapping film WF with a primer for forming a primer layer thereon. The primer layer is also called a pretreatment layer, ink penetration layer, and ink absorbing layer. The primer is a coating solution and is also called a base coating solution, and surface preparation solution. Specifically, the coating unit <NUM> has a pan <NUM>, a gravure roller <NUM>, and a transport device <NUM>. The pan <NUM> stores the primer. The gravure roller <NUM> has a lower portion thereof partially immersed in the primer stored in the pan <NUM> and, by rotating, an upper portion supplying the primer to the printing surface of soft wrapping film WF. The transport device <NUM> unwinds the soft wrapping film WF from the sheet feeder <NUM>, and transports the soft wrapping film WF to the gravure roller <NUM>. In the area where the primer is supplied to the gravure roller <NUM>, the transport direction of the soft wrapping film WF is opposite to the rotating direction of the circumferential surface of the gravure roller <NUM>. The primer is applied to the soft wrapping film WF by what is called the reverse kiss mode. The transport device <NUM> transports the soft wrapping film WF from the coating unit <NUM> to the printing unit <NUM>, with the soft wrapping film WF having the printing surface coated with the primer and facing up.

The primer includes a resin, polyvalent metallic salt, alcohol, surface tension regulator, or deionized water, for example. The resin may be shellac, for example. The polyvalent metallic salt may be calcium lactate, for example. The alcohol may be ethanol, for example. The surface tension regulator may be SY-Glyster, for example.

The printing unit <NUM> has a color printing section <NUM>, a predrying section <NUM>, a white printing section <NUM>, an upper drying section <NUM>, and a transport device <NUM>. The color printing section <NUM>, by dispensing multicolor inks, for example, prints color images on the printing surface of soft wrapping film WF coated with the primer layer. The predrying section <NUM> dries by way of pretreatment the printing surface of soft wrapping film WF having gone through the color printing. The white printing section <NUM> prints white images by dispensing white ink on the printing surface of soft wrapping film WF having gone through the color printing. The upper drying section <NUM> dries the printing surface of soft wrapping film WF where the white images have been printed. The transport device <NUM> transports the soft wrapping film WF from the color printing section <NUM> to the upper drying section <NUM>.

The main drying unit <NUM> carries out a process of drying both the printing surface of soft wrapping film WF printed in the printing unit <NUM> and the reverse surface. Specifically, the main drying unit <NUM> has a first drying section <NUM>, a second drying section <NUM>, a third drying section <NUM>, a first transport device <NUM>, a second transport device <NUM>, and a third transport device <NUM>. The first drying section <NUM> dries the printing surface of soft wrapping film WF transported downstream in the transport direction X by the first transport device <NUM>. The second drying section <NUM> dries both surfaces of soft wrapping film WF transported upstream in the transport direction X by the second transport device <NUM>. The third drying section <NUM> dries both surfaces of soft wrapping film WF transported downstream in the transport direction X by the third transport device <NUM>. The first drying section <NUM>, second drying section <NUM>, and third drying section <NUM> blow a gas heated to a predetermined temperature to the soft wrapping film WF. This dries the images printed on the printing surface of soft wrapping film WF. The main drying unit <NUM> blows out the gas at <NUM>-<NUM> at a flow speed of <NUM>-<NUM>/s, for example.

In this embodiment, an inspecting section <NUM> is provided in the most downstream position inside the main drying unit <NUM>. The detailed construction of this inspecting section <NUM> will be described hereinafter. The inspecting section <NUM> corresponds to the "inspecting apparatus" in this invention.

The takeup roller <NUM> winds up the soft wrapping film WF having gone through the drying process by the main drying unit <NUM>, into a roll form around a horizontal axis.

The inspecting section <NUM> will now be described with reference to <FIG> and <FIG>. <FIG> is a side view showing a principal portion of the inspecting section. <FIG> is a perspective view showing the construction of a transport roller in Embodiment <NUM>.

The inspecting section <NUM> has a transport roller <NUM>, a transport roller <NUM>, a frame <NUM>, a photographing device <NUM>, and a transmitted light source <NUM>.

The transport roller <NUM> and transport roller <NUM> transport the soft wrapping film WF. Specifically, the transport roller <NUM> feeds in the film WF from a left side in the transport direction X, and turns and feeds the film WF downward in the height direction Z. The transport roller <NUM> is located downward in the height direction Z from the transport roller <NUM>. The transport roller <NUM> is located to have its center of rotation spaced a distance L1 from the center of rotation of the transport roller <NUM>. The distance L1 is <NUM>, for example. The transport roller <NUM> changes and feeds the soft wrapping film WF from downward to leftward in the transport direction X.

The frame <NUM> is disposed in a position in the height direction Z between the transport rollers <NUM> and <NUM> and opposed to the transport rollers <NUM> and <NUM> across the soft wrapping film WF (in the -X direction). In particular, the frame <NUM> is located rightward in the transport direction X of the transport roller <NUM>. The frame <NUM> is attached to an apparatus frame (not shown) which rotatably holds the transport rollers <NUM> and <NUM>. The frame <NUM> is formed of a cylindrical member, for example. The frame <NUM> is elongated in the transverse direction Y. The frame <NUM> has the photographing device <NUM> mounted on an upper surface thereof. The photographing device <NUM> is elongated in the transverse direction Y as is the frame <NUM>.

The photographing device <NUM> has an image sensor 51a in a middle portion thereof. The photographing device <NUM> has an upper reflected light source 51b above the image sensor 51a in the height direction Z. The photographing device <NUM> has a lower reflected light source 51c below the image sensor 51a in the height direction Z. The image sensor 51a is a CIS (contact image sensor), for example. The upper reflected light source 51b and lower reflected light source 51c emit lights leftward in the transport direction X from the photographing device <NUM>, that is to the opposite side toward the printing surface of the soft wrapping film WF transported by the transport rollers <NUM> and <NUM>. The upper reflected light source 51b and lower reflected light source 51c are formed of light emitting diodes, for example. The transmitted light source <NUM> is located opposite the photographing device <NUM> in the transport direction X across the soft wrapping film WF. The transmitted light source <NUM> is formed of a light emitting diode, for example. The above upper reflected light source 51b, lower reflected light source 51c, and transmitted light source <NUM> mainly emit lights to the soft wrapping film WF. However, the lights from the upper reflected light source 51b and transmitted light source <NUM> are emitted also to the lower outer circumferential surface of the transport roller <NUM>. The lights from the lower reflected light source 51c and transmitted light source <NUM> are emitted also to the upper outer circumferential surface of the transport roller <NUM>.

The above photographing device <NUM> takes photographs between the transport rollers <NUM> and <NUM>. Specifically, the photographing device <NUM> takes photographs of an inspection area IA. The inspection area IA is located between the transport rollers <NUM> and <NUM>, and is set to a substantially middle part of the distance L1. The above photographing device <NUM> detects reflected light and transmitted light from the inspection area IA with the image sensor 51a, thereby to read print images printed on the printing surface of soft wrapping film WF.

The transport rollers <NUM> and <NUM> noted above are conventionally used metal rollers. For example, the transport rollers <NUM> and <NUM> have silver-colored outer circumferential surfaces. In this embodiment, the outer circumferential surfaces of these transport rollers <NUM> and <NUM> have been treated.

Specifically, the treatment is as shown in <FIG>.

Each of the transport rollers <NUM> and <NUM> has a narrow black tape <NUM> spirally wound on the outer circumferential surface about the long axis of the transport roller <NUM> or <NUM>. The black tape has been provided with antireflection treatment on its surface. The antireflection treatment is performed, for example, in the form of pearskin treatment to provide matting effect. By way of antireflection treatment, antireflection film may be coated on the surface of black tape. A black tape <NUM> having a width corresponding to the length in the transverse direction Y of the transport rollers <NUM> and <NUM> may be wound to make only one round on the outer circumferential surface of each transport roller <NUM> or <NUM>.

The above transport roller <NUM> corresponds to the "first transport roller" in this invention. The transport roller <NUM> corresponds to the "second transport roller" in this invention. The upper reflected light source 51b, lower reflected light source 51c, and the transmitted light source <NUM> correspond to the "light emitting device" in this invention. The black tape <NUM> corresponds to the "light absorbing member" in this invention.

The inspecting section <NUM> in this embodiment includes the black tapes <NUM> wound on the outer circumferential surfaces of the transport rollers <NUM> and <NUM> for absorbing the lights from the upper reflected light source 51b, lower reflected light source 51c, and transmitted light source <NUM>. Consequently, the emitted lights are inhibited from reflecting from the lower outer circumferential surface of the transport roller <NUM> and the upper outer circumferential surface of the transport roller <NUM>. As a result, noise in the photographing device <NUM> due to the lights reflected from the transport rollers <NUM> and <NUM> can be suppressed. The inspecting section <NUM> can perform accurate inspection. The use of black tapes <NUM> contributes to low cost. Further, the black tapes <NUM>, which are simply wound for use, are easily applicable also to existing apparatus.

This invention is not limited to the foregoing embodiment, but may be modified as the following example. Reference is made to <FIG> is a view in vertical section showing the construction of a transport roller in the modified example, with a portion thereof enlarged.

In this modified example, the outer circumferential surfaces of the transport rollers <NUM> and <NUM> have a needlelike construction <NUM>. Specifically, the needlelike construction <NUM> is formed of numerous recesses 57a and numerous projections 57b. Their surfaces are covered with a black coat. In this construction, the outer circumferential surfaces of transport rollers <NUM> and <NUM> are formed of light absorbing members. Specifically, the recesses 57a and projections 57b in the needlelike construction <NUM> on the outer circumferential surfaces of transport rollers <NUM> and <NUM> preferably are in an aspect ratio of <NUM> or more and not exceeding <NUM>. With such a construction, the lights emitted to the needlelike construction <NUM> are absorbed by the needlelike construction, whereby reflection can be suppressed. Further, the black coat preferably is a conductive metal. A conductive metal, with static electricity, can inhibit powder entering the transport rollers <NUM> and <NUM>. This can prevent lowering of the light absorbing performance due to the entry of powder. Consequently, performance can be maintained over a long period of time.

As described above, the outer circumferential surfaces of transport rollers <NUM> and <NUM> have the needlelike construction <NUM> with numerous recesses 57a and numerous projections <NUM>, which are coated with the black coat. Consequently, durability is made excellent, and the effect can be maintained over a long period of time.

Next, Embodiment <NUM> of this invention will be described with reference to the drawings. <FIG> is a side view showing a principal portion of an inspecting section in Embodiment <NUM>.

An inspecting section 43A in Embodiment <NUM> is constructed as follows.

The inspecting section 43A is different from the foregoing inspecting section <NUM> in the construction of an upper reflected light source 51b1, a lower reflected light source 51c1, and a transmitted light source 53a. Specifically, the upper reflected light source 51b1 and lower reflected light source 51c1 emit lights to the soft wrapping film WF from the right side in the transport direction X. However, the upper reflected light source 51b1 and lower reflected light source 51c1 have their light emitting directions narrowed. In other words, the upper reflected light source 51b1 and lower reflected light source 51c1 have directionality. This directionality effects restrictions, with respect to the height direction Z, on the light emission to the lower outer circumferential surface of the transport roller <NUM>, and on the light emission to the upper outer circumferential surface of the transport roller <NUM>. However, the above directionality allows the light emission to the inspection area IA. The transmitted light source 53a also has a similar directivity. Such directivity can be realized by devising lens shapes of the light sources, for example.

The above upper reflected light source 51b1, lower reflected light source 51c1, and transmitted light source 53a correspond to the "light irradiation restricting device" in this invention.

According to this embodiment, the problem due to the reflected light from the transport rollers <NUM> and <NUM> can be solved by devising only the construction for emitting light.

Next, Embodiment <NUM> of this invention will be described with reference to the drawings. <FIG> is a side view showing a principal portion of an inspecting device in Embodiment <NUM>.

An inspecting section 43B in Embodiment <NUM> is constructed as follows.

In the inspecting section 43B, the photographing device <NUM> has hoods <NUM>, and the transmitted light source <NUM> has hoods <NUM>. Specifically, the hoods <NUM> are attached to an upper part of the upper reflected light source 51b and a lower part of the lower reflected light source 51c. The hoods <NUM> are attached to an upper part and a lower part of the transmitted light source <NUM>. The hoods <NUM> and <NUM> allow the light emission to the inspection area IA. On the other, the hoods <NUM> and <NUM> effect restrictions, with respect to the height direction Z, on the light emission to the lower outer circumferential surface of the transport roller <NUM>, and on the light emission to the upper outer circumferential surface of the transport roller <NUM>.

The above hoods <NUM> and <NUM> correspond to the "light irradiation restricting device" in this invention.

According to this embodiment, the hoods <NUM> and <NUM> are provided for preventing the light emission to the transport rollers <NUM> and <NUM>. Consequently, the problem due to the reflected lights from the transport rollers <NUM> and <NUM> can be solved only by providing the hoods <NUM> for the upper reflected light source 51b and lower reflected light source 51c, and the hoods <NUM> for the transmitted light source <NUM>. Consequently, this construction is easily applicable also to existing apparatus.

This invention is not limited to the embodiment having the hoods <NUM> attached to the photographing device <NUM>, and the hoods <NUM> attached to the transmitted light source <NUM>. That is, it will serve the purpose to arrange shielding members arranged in positions for obstructing the lights from the light sources reaching the outer circumferential surfaces of transport rollers <NUM> and <NUM>. The arranging positions of the hoods <NUM> and hoods <NUM> are not limited to the positions described above.

An inspecting section 43C in Embodiment <NUM> is constructed as follows.

In the inspecting section 43B, the transport roller <NUM> and transport roller <NUM> are spaced apart by a distance L2 in the height direction Z therebetween. This distance L2 is longer than the distance L1 in the inspecting section <NUM> of Embodiment <NUM>. The distance L2 is such a length that the lights from the upper reflected light source 51b, lower reflected light source 51c, and transmitted light source <NUM> do not irradiate the lower outer circumferential surface of the transport roller <NUM> or the upper outer circumferential surface of the transport roller <NUM>. In other words, the transport roller <NUM> and transport roller <NUM> are arranged to have the lower outer circumferential surface of the transport roller <NUM> and the upper outer circumferential surface of the transport roller <NUM> located outside areas irradiated by the lights from the upper reflected light source 51b, lower reflected light source 51c, and transmitted light source <NUM>.

The above transport rollers <NUM> and <NUM> arranged at the interval of distance L2 in the height direction Z correspond to the "light irradiation restricting device" in this invention.

According to this embodiment, the distance L2 between the transport roller <NUM> and transport roller <NUM> at opposite ends of the inspection area IA where the soft wrapping film WF is transported is set so that the transport roller <NUM> and transport roller <NUM> are outside the areas irradiated by the lights from the upper reflected light source 51b, lower reflected light source 51c, and transmitted light source <NUM>. Consequently, the problem due to the reflected lights from the transport rollers <NUM> and <NUM> can be solved without adding a new construction.

An inspecting section 43D in Embodiment <NUM> is constructed as follows. The inspecting section 43D is, in the construction itself, the same as the inspecting section <NUM> in Embodiment <NUM> described hereinbefore. However, the positions of arrangement relative to the transport rollers <NUM> and <NUM> are different.

First, in the construction in this embodiment, the positions of the photographing device <NUM> and transmitted light source <NUM> opposed to each other across the soft wrapping film WF transported by the transport roller <NUM> and transport roller <NUM> are swapped with respect to the inspecting section <NUM> in Embodiment <NUM>. Specifically, the inspecting section 43D has the photographing device <NUM> located on the lefthand side in the transport direction X of the soft wrapping film WF. The inspecting section 43D has the transmitted light source <NUM> located on the righthand side in the transport direction X of the soft wrapping film WF.

Further, the photographing device <NUM> is arranged in a position in the transport direction X different from the inspecting section <NUM> in Embodiment <NUM>. The photographing device <NUM> in this embodiment, with reference to the soft wrapping film WF transported between the transport roller <NUM> and transport roller <NUM>, is located in a position between the transport rollers <NUM> and <NUM> and on the same side as the transport rollers <NUM> and <NUM> (in the X-direction from the soft wrapping film WF. More preferably, the light incident surface of the image sensor 51a is located closer to a center line CL linking the rotation centers of the transport roller <NUM> and transport roller <NUM> than tangents to leftward outer circumferential surfaces of both the transport roller <NUM> and transport roller <NUM>.

Thus, the photographing device <NUM> occupies an area between the transport rollers <NUM> and <NUM>. This can inhibit lights reflected by opposed outer circumferential surfaces of the transport rollers <NUM> and <NUM> from entering the photographing device <NUM>. Consequently, the problem due to the reflected lights from the transport rollers <NUM> and <NUM> can be solved only by changing the position of the photographing device <NUM>.

Reference is now made to <FIG> and <FIG>. <FIG> is a side view of a moving mechanism in the inspecting section. <FIG> is a plan view of the moving mechanism in the inspecting section.

In each of Embodiments <NUM>-<NUM> described above, a primer layer is formed in the coating unit <NUM> before printing to promote fixation of the inks dispensed from the printing unit <NUM>. Consequently, the powder of the primer layer may adhere to the photographing device <NUM> (especially the light incident surface), thereby interfering with accurate inspection. Also where the printing medium is paper instead of the soft wrapping film WF, paper powder may adhere to the photographing device <NUM> to cause the same problem. It is therefore necessary to clean regularly the surface of the photographing device <NUM> opposed to the printing medium transported. However, where the image sensor 51a of the photographing device <NUM> is a CIS (contact image sensor), the depth of field is shallow. There is therefore a small distance between the light transmitting surface of the photographing device <NUM> and the printing medium. This poses a problem that maintenance of the photographing device <NUM> is difficult. It is preferable to provide the following moving mechanism <NUM>.

The moving mechanism <NUM> fixes the position relative to the inspection area IA of the photographing device <NUM> at a time of operation of the inkjet printing apparatus <NUM>. At a time of maintenance, on the other hand, the photographing device <NUM> is movable to be spaced from the inspection area IA and away from the plane of the soft wrapping film WF.

Specifically, the moving mechanism <NUM> has an apparatus frame <NUM> and a swing pin <NUM>. The transport roller <NUM> and transport roller <NUM> are rotatably attached to the apparatus frame <NUM>. In particular, the transport rollers <NUM> and <NUM> have rotary shafts extending in the transverse direction Y with opposite ends thereof rotatably attached to the apparatus frame <NUM>. The swing pin <NUM> is inserted adjacent one end of a frame <NUM> on which the photographing device <NUM> is mounted. The swing pin <NUM> is placed to have an axis thereof extending parallel to the plane of the soft wrapping film WF. The apparatus frame <NUM> has a support plate <NUM> erected adjacent the one end of the frame <NUM>. The support plate <NUM> has a pin stop plate <NUM> attached to an upper part thereof. The swing pin <NUM> projects downward from the frame <NUM>, and has a lower part thereof inserted in the pin stop plate <NUM>. Consequently, as shown in a two-dot chain line in <FIG>, the frame <NUM> can swing about a pivot axis P1 of the swing pin <NUM> along an upper surface of the support plate <NUM> and along a plane defined by the transport direction X and transverse direction Y. In other words, the photographing device <NUM> can swing with the frame <NUM> along the plane defined by the transport direction X and transverse direction Y.

The above frame <NUM> corresponds to the "photographing device frame" in this invention.

The apparatus frame <NUM> has a frame positioning pin <NUM> which restricts a position of the other end of the frame <NUM> to place the photographing device <NUM> in a focusing position for focusing on the soft wrapping film WF. Specifically, the apparatus frame <NUM> has the support plate <NUM> attached thereto on the opposite side in the transverse direction Y of the swing pin <NUM>. The frame positioning pin <NUM> is attached to an upper part of the support plate <NUM>. The frame positioning pin <NUM> has a lower part thereof embedded in the support plate <NUM>, and an upper part projecting in the height direction Z from the upper surface of the support plate <NUM>. An L-plate <NUM> is attached to a side surface at the other end of the frame <NUM>. The L-plate <NUM> assumes a shape of letter L of the alphabet in plan view as shown in <FIG>. The L-plate <NUM> has a portion horizontal in the transverse direction Y, which portion contacts the frame positioning pin <NUM>. The L-plate <NUM> in contact with the frame positioning pin <NUM> is fixed to the support plate <NUM> with screws <NUM>, thereby fixing the position of the frame <NUM>.

With the moving mechanism <NUM> provided as above, the photographing device <NUM> can be moved away from the plane of the soft wrapping film WF at the time of maintenance. Consequently, powder and the like released from the soft wrapping film WF can easily be removed from the photographing device <NUM>. This enables accurate inspection to be performed over a long period of time. Further, with the frame positioning pin <NUM>, the position of the frame <NUM> at the other end of the frame <NUM> is restricted to place the photographing device <NUM> in the focusing position. Consequently, after swinging the frame <NUM> for maintenance of the photographing device <NUM>, photography by the photographing device <NUM> restored can be performed appropriately.

The frame <NUM> preferably is constructed as shown in <FIG>. <FIG> is a plan view of the moving mechanism in the inspecting section. <FIG> is a front view of a photographing device moving mechanism in the inspecting section. <FIG> is a plan view of the photographing device moving mechanism in the inspecting section.

That is, the frame <NUM> preferably has a photographing device moving mechanism <NUM> for enabling movement of the position in the transport direction X of the photographing device <NUM> relative to the inspection area IA.

The photographing device moving mechanism <NUM> has mounting plates <NUM>, rails <NUM>, photographing device positioning pins <NUM>, restrictor pieces <NUM>, and screws <NUM>.

The mounting plates <NUM> are attached to opposite end regions in the transverse direction Y of the photographing device <NUM>. Each mounting plate <NUM> assumes a shape of letter L. Each rail <NUM> is attached to the frame <NUM> below the mounting plate <NUM>. The rail <NUM> has a groove in a middle portion thereof seen in the transport direction X. In the rail <NUM> the groove is formed along the transport direction X. Each photographing device positioning pin <NUM> is attached to the mounting plate <NUM> to project downward from a lower surface thereof. Each restrictor piece <NUM> is fixedly provided in the groove of the rail <NUM>. The restrictor piece <NUM> is fixed as opposed to the soft wrapping film WF in the transport direction X. When the photographing device <NUM> is moved along the transport direction X with the photographing device positioning pin <NUM> inserted in the groove of the rail <NUM>, the photographing device positioning pin <NUM> will contact the restrictor piece <NUM> to restrict the movement. This position is set as a focusing position where the photographing device <NUM> focuses on printed images in the inspection area IA of the soft wrapping film WF. The screws <NUM> are attached in the state where the photographing device positioning pin <NUM> contacts the restrictor piece <NUM> to restrict the movement. Consequently, the photographing device <NUM> is fixed to the frame <NUM> in the focusing position.

Thus, with the photographing device moving mechanism <NUM>, the photographing device <NUM>, even if moved at the time of maintenance, can easily be set to the focusing position.

Claim 1:
An inspecting apparatus (<NUM>) for reading print images printed by dispensing ink droplets on a transparent printing medium (WF) and inspecting printing states, the apparatus (<NUM>) comprising:
a first transport roller (<NUM>) for transporting the transparent printing medium (WF);
a second transport roller (<NUM>) spaced from the first transport roller (<NUM>), and disposed downstream in a transport direction (X), for transporting the transparent printing medium (WF);
a photographing device (<NUM>) disposed between the first transport roller (<NUM>) and the second transport roller (<NUM>), and opposed to one surface of the transparent printing medium (WF), for photographing the print images located in an inspection area (IA) set between the first transport roller (<NUM>) and the second transport roller (<NUM>); and
a light emitting device for emitting light for the photographing device (<NUM>) to photograph the print images located in the inspection area (IA), the light emitting device including at least a transmitted light source (<NUM>) disposed opposed to the photographing device (<NUM>) with the transparent printing medium (WF) interposed between the transmitted light source (<NUM>) and the photographing device (<NUM>);
wherein the first transport roller (<NUM>) and the second transport roller (<NUM>) have outer circumferential surfaces thereof each with a light absorbing member (<NUM>) for absorbing the light from the light emitting device.