Circuit board, optical sensor, and image formation device

Abstract

To facilitate a confirmation that an electronic component is correctly mounted to a predetermined position.SOLUTION: A circuit board includes: a base material; and a conductive pattern provided onto the base material. The conductive pattern includes: an electrode pad to which an electronic component is mounted; and a first teaching pattern that includes a first line and a second line for teaching a range where the electronic component can be mounted. In view of a direction orthogonal to a mounting surface of the circuit board, the electronic component includes a first side surface extended to a first direction as a direction along the mounting surface. Both of the first line and the second line are extended. In a second direction orthogonal to the first direction and the mounting surface, a first side surface is existed between the first line and the second line. In the first direction, both of the first line and the second line are positioned to a position that is different from the first side surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a printed circuit board, an optical sensor, and an image forming apparatus. [Background technology]

[0002] There are various types of electronic components with different electrode or terminal arrangements. If the electronic components are not mounted in the correct position on the surface of the printed circuit board, the electronic components will not function correctly. Therefore, thin lines indicating the positions where the electrodes of the electronic components are to be placed on the surface of the printed circuit board are formed by silk screen printing (Patent Document 1). Solder balls, which are the electrodes of ball grid array (BGA) type electronic components, are placed on the back side of the electronic components. For this reason, confirmation lines are silk screen printed to allow the outline of the BGA and the positional misalignment of the printed circuit board to be confirmed with the naked eye (Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-12771 A [Patent Document 2] JP 2000-133898 A Summary of the Invention [Problem to be solved by the invention]

[0004] The process of performing silk screen printing to indicate the mounting positions of electronic components is different from the process of creating the lands (electrode pads) on which the electronic components are mounted. Therefore, the positional deviation of the silk screen printing lines relative to the lands is likely to be large. As a result, when electronic components are placed according to the silk screen printing lines, the electronic components are sometimes not placed in the correct positions on the printed circuit board. Therefore, an object of the present invention is to make it easier to check that electronic components are correctly mounted in the specified positions. [Means for solving the problem]

[0005] The present invention is, for example, A substrate; A conductive pattern provided on the substrate, The conductive pattern is An electrode pad on which an electronic component is mounted; a first teaching pattern having a first line and a second line, the first teaching pattern teaching a mountable range of the electronic component; A printed circuit board having When viewed in a direction perpendicular to a mounting surface of the printed circuit board, the electronic component has a first side extending in a first direction that is a direction along the mounting surface, the first line and the second line extend in the first direction; In a second direction perpendicular to the first direction and the mounting surface, the first side surface is between the first line and the second line; The printed circuit board is provided such that, in the first direction, the first line and the second line are at different positions from the first side. Effect of the Invention

[0006] According to the present invention, it is easy to confirm whether electronic components are correctly mounted in predetermined positions. [Brief description of the drawings]

[0007] [Figure 1] Diagram explaining a printed circuit board [Diagram 2] FIG. 13 is a diagram illustrating a silk screen mark printed on the surface of a printed circuit board. [Diagram 3] Diagram explaining a printed circuit board [Figure 4] Diagram explaining a printed circuit board [Diagram 5] Diagram explaining a printed circuit board [Figure 6] Diagram explaining a printed circuit board [Figure 7] Diagram explaining a printed circuit board [Figure 8] Diagram explaining a printed circuit board [Figure 9]Diagram explaining a printed circuit board [Figure 10] Figures suggesting other shapes of teaching patterns [Figure 11] Diagram explaining optical sensors [Figure 12] FIG. 1 is a diagram illustrating an image forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0009] <Example 1> (1) Structure of printed circuit board FIG. 1(A) is a plan view of the printed circuit board 100 in the first embodiment. FIG. 1(B) is a cross-sectional view of the printed circuit board 100 taken along the HH cutting line. FIG. 1(C) is a cross-sectional view of the printed circuit board 100 taken along the GG cutting line. z indicates the height direction of the printed circuit board 100. x and y indicate directions parallel to the mounting surface of the printed circuit board 100. An electronic component 110 is mounted on the mounting surface of the printed circuit board 100. In this specification, lowercase alphabets such as abcd may be added to the end of reference symbols. This is added to distinguish between identical or similar elements. Therefore, when common matters regarding identical or similar elements are described, the lowercase alphabets may be omitted.

[0010] The printed circuit board 100 has an insulating base material 102, a conductive pattern 104, and a resist 101. The insulating base material 102 is a glass epoxy resin or the like. The conductive pattern 104 is a copper foil or the like formed or laminated on the base material 102. The resist 101 is an insulating layer formed or laminated on the conductive pattern 104. Parts of the conductive pattern 104 that are soldered to the electrodes of the electronic component 110 are called electrode pads 107a, 107b. The electrode pads 107a, 107b may be called lands. Solder 103 is present between the electronic component 110 and the electrode pads 107a, 107b. The electrodes 105a, 105b of the electronic component 110 and the conductive pattern 104 are joined by the solder 103, and are electrically connected to each other.

[0011] The thickness of conductive pattern 104 in the z direction is, for example, 35 um. um is an abbreviation for micrometer. Electrode pads 107a and 107b are parts of conductive pattern 104. Resist 101 is an insulating layer provided on printed circuit board 100 and on the upper layer of conductive pattern 104. The thickness of resist 101 in the z direction is, for example, 30 um. Although conductive pattern 104 is covered with resist 101, the shape of conductive pattern 104 is visible. This is because resist 101 is translucent.

[0012] The substrate 102 has a first side 121a, a second side 121b, a third side 121c, and a fourth side 121d. The first side 121a and the third side 121c are parallel. The second side 121b and the fourth side 121d are parallel. The first side 121a and the second side 121b are perpendicular to each other. In the specification, the order particles such as first and second are added merely for the convenience of explanation.

[0013] The electronic component 110 has a first side surface 122a, a second side surface 122b, a third side surface 122c, and a fourth side surface 122d. The first side surface 122a and the third side surface 122c are parallel to each other. The second side surface 122b and the fourth side surface 122d are parallel to each other. The first side surface 122a and the second side surface 122b are perpendicular to each other. The first side surface 122a, the second side surface 122b, the third side surface 122c, and the fourth side surface 122d extend in a direction along the mounting surface of the substrate 102 and the printed circuit board 100.

[0014] (2) Comparative Example 2 shows a comparative example. The silk characters 106 and silk marks 108a to 108d are printed on the resist 101. The silk characters 106 and silk marks 108a to 108d are printed with, for example, non-conductive epoxy ink. The thickness of the silk characters 106 in the z direction is, for example, 30 um. The printing process of the silk characters 106 and silk marks 108a to 108d is different from the forming process of the conductive pattern 104.

[0015] The silkscreen letters 106 indicate the location number of the electric element (A100, which is the location number of the electronic component 110). The silkscreen marks 108a to 108d indicate the range on the printed circuit board 100 where the electronic component 110 can be mounted.

[0016] Silk marks 108a-108d have an L-shape. If the four corners of electronic component 110 are located inside silk marks 108a-108d, the mounting position of electronic component 110 is correct. However, the printing process of silk marks 108a-108d and the forming process of conductive pattern 104 are separate processes. Therefore, the positions of silk marks 108a-108d relative to conductive pattern 104 vary. As a result, even if electronic component 110 is placed inside silk marks 108a-108d, electronic component 110 may be misaligned with respect to electrode pads 107a, 107b.

[0017] (3) Marks to indicate the mounting positions of electronic components (3-1) Alignment of electronic components in the y direction 3(A) to 3(C) are plan views showing the surface of the printed circuit board 100 with the resist 101 omitted. FIG. 3(A) also shows an enlarged view of the teaching pattern 120a. The teaching pattern 120a is a conductive pattern formed in the same process as the conductive pattern 104. That is, since the teaching pattern 120a and the electrode pads 107a and 107b are manufactured in the same process, the positional relationship between the teaching pattern 120a and the electrode pads 107a and 107b is accurate. The teaching pattern 120a has a predetermined shape. The predetermined shape has a concave shape composed of two parallel lines 131a and 132a and a line 133a. The line 133a connects the two lines 131a and 132a. The two imaginary lines 112a and 111a are lines shown for convenience of explanation, and are imaginary lines obtained by extending the two lines 131a and 132a, respectively. The two lines 131a, 132a and the two imaginary lines 112a, 111a are parallel to the second side surface 122b of the electronic component 110 which intersects with the first side surface 122a.

[0018] Two lines 131a, 132a and two virtual lines 112a, 111a indicate the mountable range in the y direction of electronic component 110. Line 131a and virtual line 112a indicate one limit position (upper limit position) of the mountable range of electronic component 110. Line 132a and virtual line 111a indicate the other limit position (lower limit position) of the mountable range of electronic component 110.

[0019] 3A, the second side surface 122b of the electronic component 110 is located between the two lines 131a, 132a (the two imaginary lines 112a, 111a) constituting the teaching pattern 120a. Therefore, it can be seen that the electronic component 110 is accurately placed on the printed circuit board 100.

[0020] 3B, the electronic component 110 is arranged with a deviation in the -y direction. The second side surface 122b of the electronic component 110 is not located between the two lines 131a, 132a (the two imaginary lines 112a, 111a) that constitute the teaching pattern 120a. Therefore, it can be seen that the electronic component 110 is not accurately arranged with respect to the printed circuit board 100.

[0021] 3(C), the electronic component 110 is arranged with a deviation in the +y direction. The second side surface 122b of the electronic component 110 is not located between the two lines 131a, 132a (the two imaginary lines 112a, 111a) that constitute the teaching pattern 120a. Therefore, it can be seen that the electronic component 110 is not accurately arranged with respect to the printed circuit board 100.

[0022] (3-2) Alignment of electronic components in the x direction 4(A) to 4(C) are plan views showing the surface of the printed circuit board 100 with the resist 101 omitted. FIG. 4(A) also shows an enlarged view of the teaching pattern 120b. The teaching pattern 120b is a conductive pattern formed in the same process as the conductive pattern 104. That is, since the teaching pattern 120b and the electrode pads 107a and 107b are manufactured in the same process, the positional relationship between the teaching pattern 120b and the electrode pads 107a and 107b is accurate. The teaching pattern 120b has a predetermined shape, which is a concave shape composed of two parallel lines 131b and 132b and a line 133b. The line 133b connects the two lines 131b and 132b. The two imaginary lines 112b and 111b are lines shown for convenience of explanation, and are imaginary lines obtained by extending the two lines 131b and 132b, respectively. The two lines 131 b , 132 b and the two imaginary lines 112 b , 111 b are parallel to the first side surface 122 a of the electronic component 110 .

[0023] Two lines 131b, 132b and two imaginary lines 112b, 111b indicate the mountable range in the x direction of electronic component 110. Line 131b and imaginary line 112b indicate the upper limit position of the mountable range of electronic component 110. Line 132b and imaginary line 111b indicate the lower limit position of the mountable range of electronic component 110.

[0024] 4A, the first side surface 122a of the electronic component 110 is located between the two lines 131b, 132b (the two imaginary lines 112b, 111b) that form the teaching pattern 120b. Therefore, it can be seen that the electronic component 110 is accurately placed on the printed circuit board 100.

[0025] 4(B), the electronic component 110 is arranged with a deviation in the +x direction. The first side surface 122a of the electronic component 110 is not located between the two lines 131b, 132b (the two imaginary lines 112b, 111b) that constitute the teaching pattern 120b. Therefore, it can be seen that the electronic component 110 is not accurately arranged with respect to the printed circuit board 100.

[0026] 4(C), the electronic component 110 is shifted in the -x direction. The first side surface 122a of the electronic component 110 is not located between the two lines 131b, 132b (the two imaginary lines 112b, 111b) that form the teaching pattern 120a. Therefore, it can be seen that the electronic component 110 is not accurately placed on the printed circuit board 100.

[0027] (3-3) Teaching pattern for positioning two sides of electronic components FIG. 5 shows another example of the teaching patterns 120a and 120b. The electronic component 110 is arranged so that the second side surface 122b and the fourth side surface 122d of the electronic component 110 are located between the two lines 131a and 132a (two imaginary lines 112a and 111a) constituting the teaching pattern 120a. Similarly, the electronic component 110 is arranged so that the first side surface 122a and the third side surface 122c of the electronic component 110 are located between the two lines 131b and 132b (two imaginary lines 112b and 111b) constituting the teaching pattern 120b. In this way, a single teaching pattern 120a may indicate the mountable range of the two side surfaces of the electronic component 110. In this case, the distance between the two lines 131a and 132a constituting the teaching pattern 120a is longer than the length of the first side surface 122a and longer than the length of the third side surface 122c.

[0028] Similarly, a single teaching pattern 120b may indicate the mountable range of two sides of electronic component 110. In this case, the distance between two lines 131b and 132b constituting teaching pattern 120b is longer than the length of second side surface 122b and longer than the length of fourth side surface 122d.

[0029] In this way, the electronic component 110 is positioned accurately in the y direction by arranging the electronic component 110 inside the teaching pattern 120a. The electronic component 110 is positioned accurately in the x direction by arranging the electronic component 110 inside the teaching pattern 120b.

[0030] (3-4) Other examples of teaching patterns Fig. 6 shows that taught pattern 120a is realized by two taught patterns 601 and 602, and taught pattern 120b is realized by two taught patterns 603 and 604. According to Fig. 6, taught pattern 601 teaches the mountable range of second side surface 122b of electronic component 110. Taught pattern 602 teaches the mountable range of fourth side surface 122d of electronic component 110. Taught pattern 603 teaches the mountable range of first side surface 122a of electronic component 110. Taught pattern 604 teaches the mountable range of third side surface 122c of electronic component 110.

[0031] In this manner, teaching patterns 120a, 120b formed in the same process as electrode pads 107a, 107b are adopted. As a result, in the first embodiment, compared to silk marks 108a-108d, it becomes possible to accurately position electronic component 110 with respect to electrode pads 107a, 107b. Note that, instead of silk marks 108a-108d, a conductive pattern having the same shape (e.g., L-shape) as silk marks 108a-108d may be adopted as the teaching pattern.

[0032] <Example 2> (1) Teaching pattern using convex shapes In the first embodiment, the shapes of the teaching patterns 120a and 120b are both concave. However, the shapes of the teaching patterns 120a and 120b may be other shapes as long as they can teach the mounting position of the electronic component 110. Therefore, in the second embodiment, a convex shape is introduced as the shape of the teaching patterns 120a and 120b. In the second embodiment, a description of matters that are the same as or similar to those in the first embodiment will be omitted, and the description of the first embodiment will be used.

[0033] (2) Alignment in the y direction 7(A) to 7(C) are plan views showing the surface of the printed circuit board 100 with the resist 101 omitted. The teaching pattern 120a has two convex shapes (first convex shape 701 and second convex shape 702) protruding in the -x direction. The two convex shapes teach the mountable range of the second side surface 122b of the electronic component 110 in the y direction. In other words, two imaginary lines 112a and 111a showing between the two convex shapes show the mountable range of the second side surface 122b in the y direction. The two convex shapes may be called protrusions. The two imaginary lines 112a and 111a are parallel to the second side surface 122b. The two imaginary lines 112a and 111a are perpendicular to the y direction. Similarly, the second side surface 122b is perpendicular to the y direction.

[0034] According to FIG. 7(A), the second side surface 122b of the electronic component 110 is disposed between two imaginary lines 111a and 112a extending in the -x direction from the two convex shapes forming the teaching pattern 120a. Thus, the electronic component 110 is correctly mounted in the y direction. In FIG. 7(B), the second side surface 122b of the electronic component 110 is disposed shifted in the -y direction with respect to the teaching pattern 120a. Thus, the electronic component 110 is not correctly mounted in the y direction. In FIG. 7(C), the second side surface 122b of the electronic component 110 is disposed shifted in the +y direction with respect to the teaching pattern 120a. Thus, the electronic component 110 is not correctly mounted in the y direction. In this way, even if the teaching pattern 120a is realized by two convex shapes, the mounting position of the electronic component 110 in the y direction can be visually confirmed.

[0035] (2) Alignment in the x-direction 8(A) to 8(C) are plan views showing the surface of printed circuit board 100 with resist 101 omitted. Teaching pattern 120b has two convex shapes (first convex shape 801 and second convex shape 802) protruding in the -y direction. The two convex shapes teach the mountable range of first side surface 122a of electronic component 110 in the x direction.

[0036] According to FIG. 8(A), the first side surface 122a of the electronic component 110 is disposed between two imaginary lines 111b and 112b extending in the -y direction from two convex shapes forming the teaching pattern 120b. Thus, the electronic component 110 is correctly mounted in the x direction. In FIG. 8(B), the first side surface 122a of the electronic component 110 is disposed shifted in the +x direction with respect to the teaching pattern 120b. Thus, the electronic component 110 is not correctly mounted in the x direction. In FIG. 8(C), the first side surface 122a of the electronic component 110 is disposed shifted in the -x direction with respect to the teaching pattern 120b. Thus, the electronic component 110 is not correctly mounted in the x direction. In this way, even if the teaching pattern 120b is realized by two convex shapes, the mounting position of the electronic component 110 in the x direction can be visually confirmed.

[0037] Similarly to Example 1, Example 2 also employs teaching patterns 120a and 120b formed in the same process as electrode pads 107a and 107b. This makes it possible to accurately position electronic component 110 with respect to electrode pads 107a and 107b in comparison with silk marks 108a to 108d in Example 2.

[0038] A method for checking whether the electronic component 110 is mounted in the correct position may be visual inspection by a human or image processing using a camera. The distance between the teaching patterns 120a and 120b and the electronic component 110 is set to be short (e.g., 10 mm or less). However, this distance is arbitrary as long as the mounting position of the electronic component 110 can be specified through the teaching patterns 120a and 120b.

[0039] <Example 3> In the second embodiment, the teaching patterns 120a and 120b are realized by two convex shapes, but this is only an example. In the third embodiment, other shapes of the teaching patterns 120a and 120b are introduced.

[0040] (1) A teaching pattern formed by a single convex shape 9 is a plan view showing the surface of the printed circuit board 100 with the resist 101 omitted. Each of the teaching patterns 120a and 120b is realized by a single convex shape. In this manner, the extension lines of the two outer edges forming the convex shape may form two virtual lines (a pair of virtual lines 111a and 112a, and a pair of virtual lines 111b and 112b).

[0041] (2) Other examples of concave and convex shapes 10(A) to 10(C) are enlarged views of the teaching patterns 120a and 120b. In FIG. 10(A), the teaching patterns 120a and 120b are written as teaching patterns 120. The virtual lines 111a, 112a, 111b, and 112b are written as virtual lines 111 and 112. In the first embodiment, the depressions of the teaching patterns 120a and 120b are rectangular. However, the shape of the depressions may be semicircular. As shown in FIG. 10(B), the depressions of the teaching patterns 120a and 120b may be triangular. The depressions may be semicircular, etc.

[0042] In Fig. 7(A) and Fig. 8(A), the teaching patterns 120a and 120b are formed by two convex shapes. The two convex shapes are rectangular. As shown in Fig. 10(C), the two convex shapes may be triangular. In this case, two virtual lines 111 and 112 extend from the vertices of the triangle in the y direction or the x direction.

[0043] In this way, it is sufficient for the shape of the teaching patterns 120a, 120b to be able to conceive of the two imaginary lines 111, 112 that define the range within which the electronic component 110 can be mounted.

[0044] In the first to third embodiments, the combinations of the shapes of the teaching patterns 120a and 120b are a pair of convex and convex shapes, and a pair of concave and concave shapes. However, this is merely an example. The shape of the teaching pattern 120a may be a convex shape, and the shape of the teaching pattern 120b may be a concave shape. Conversely, the shape of the teaching pattern 120a may be a concave shape, and the shape of the teaching pattern 120b may be a convex shape. The examples of the convex shape and the concave shape may be any of the shapes suggested in the first to third embodiments.

[0045] <Example 4> In the fourth embodiment, several cases to which the printed circuit board 100 described in the first to third embodiments can be applied will be introduced.

[0046] (1) Optical Sensor 11 shows an optical sensor 1100. An LED 1101, which is a chip-type light-emitting element, and a PD 1102, which is a chip-type light-receiving element, are mounted on the mounting surface of a printed circuit board 100. LED is an abbreviation for Light Emitting Diode. PD is an abbreviation for Photo Diode.

[0047] An aperture 1120 is further provided on the mounting surface of the printed circuit board 100. The aperture 1120 is an optical diaphragm. The aperture 1120 has openings 1121a and 1121b and a light-shielding wall 1122. The light-shielding wall 1122 is provided so as to surround the LED 1101 and the PD 1102, respectively, and prevents the light from the LED 1101 from directly entering the PD 1102.

[0048] The opening 1121a is an opening that passes the light output from the LED 1101. The opening 1121b is an opening that passes the light coming from the outside. The aperture 1120 acts to narrow the light output from the LED 1101 and the light coming from the outside. This improves the light receiving performance of the optical sensor 1100.

[0049] The reflector 1140 is disposed so as to face the printed circuit board 100. Light output from the LED 1101 is incident on the reflector 1140 along an optical path 1160. The light is reflected by the reflector 1140, and the reflected light is incident on the PD 1102 along an optical path 1170. The PD 1102 outputs a signal according to the received light. When the light is blocked by some object such as a sheet, the level of the signal output from the PD 1102 changes. Thus, the optical sensor 1100 can be used as a sensor that detects the presence of an object. Furthermore, the PD 1102 detects the reflected light from the object and outputs a signal according to the surface properties of the object. Thus, the optical sensor 1100 can be used as a sensor that detects the surface properties (e.g., the roughness of the surface of a sheet, the presence or absence of a coating, etc.) or the type (e.g., the basis weight) of the object.

[0050] (2) Image forming device FIG. 12 shows an electrophotographic image forming apparatus 1200. The photoconductor drum 18 is an image carrier having a photosensitive layer such as an organic optical semiconductor. The photoconductor drum 18 rotates in the direction of the arrow at a predetermined process speed. The charging roller 2 charges the surface of the photoconductor drum 18 so that the surface potential of the photoconductor drum 18 becomes a predetermined potential. The laser beam scanner 3 outputs a laser beam in accordance with an image signal to expose the surface of the photoconductor drum 18 and form an electrostatic latent image.

[0051] The developer container 5 contains the toner 4. The developer carrying member 6 develops the electrostatic latent image with the toner 4 to form a toner image. The developer carrying member 6 may be called a developing roller or a developing sleeve.

[0052] The toner image is conveyed to the transfer unit 19 by the rotation of the photosensitive drum 18. The transfer unit 19 is composed of the photosensitive drum 18 and the transfer roller 7. The sheet cassette 11 is a container that accommodates a large number of sheets 8. The feed roller 12 feeds one sheet 8 from the sheet cassette 11 to the conveying path 10. The conveying roller 13 conveys the sheet 8 along the conveying path 10 to the transfer unit 19. A sheet sensor 16 is disposed downstream of the conveying roller 13. The sheet sensor 16 is realized by an optical sensor 1100. The laser beam scanner 3 outputs a laser beam based on the timing (passing timing) when the sheet sensor 16 detects the leading edge of the sheet 8. This synchronizes the timing when the toner image arrives at the transfer unit 19 and the timing when the sheet 8 arrives.

[0053] The transfer unit 19 transfers the toner image from the photoreceptor drum 18 to the sheet 8. The cleaning container 9 collects the toner 4 remaining on the photoreceptor drum 18. The photoreceptor drum 18, the charging roller 2, the developing container 5, and the cleaning container 9 are provided as an integrated unit, and may be called a process cartridge.

[0054] The sheet 8 is transported from the transfer unit 19 to the fixing unit 17. The fixing unit 17 applies heat and pressure to the toner image and the sheet 8, thereby fixing the toner image onto the sheet 8. The discharge rollers 14 discharge the sheet 8 to the outside of the image forming apparatus 1200. The toner 4 is fixed onto the sheet 8 while being heated and pressurized by the fixing unit 17. In this way, the printed matter consisting of the sheet 8 and the toner image may be antibacterial treated.

[0055] 12 shows an image forming apparatus 1200 that forms a monochrome image, the technical concept of the present invention is also applicable to an image forming apparatus that forms a full-color image. Also, the sheet 8 may be a preprinted paper that has already been printed.

[0056] An optical sensor 1100 mounted on an image forming apparatus 1200 as a sheet sensor 16 irradiates light from an LED 1101 mounted on a printed circuit board 100 to a reflector 1140, and receives the reflected light from the reflector 1140 with a PD 1102. In such an optical sensor 1100, misalignment of the mounting positions of the LED 1101 and the PD 1102, which are chip-type electronic components, can reduce the amount of received light and the detection accuracy of the sheet P or the surface properties.

[0057] Therefore, the teaching pattern 120, which is the conductive pattern described in the first to third embodiments, is adopted. As a result, the mounting positions of the LED 1101 and the PD 1102 become more accurate compared to the marks (silkscreen marks 108a to 108d) made by silk screen printing, and the detection accuracy is improved. Furthermore, stray light caused by the reflection of light by silk screen printing is suppressed, and the detection accuracy of the optical sensor 1100 is improved. Since the image forming apparatus 1200 can accurately grasp the position of the sheet P, it will be possible to form a toner image on the sheet P at an accurate position. The sheet sensor 16 may be used as a media sensor that detects the surface property or type (e.g., thick paper, thin paper, plain paper, coated paper) of the sheet S. In this case, the image forming apparatus 1200 will be able to accurately control the density of the toner image or the fixing temperature of the fixing unit 17 based on the detection result of the sheet sensor 16.

[0058] <Technical ideas derived from examples> (Item 1) A substrate; A conductive pattern provided on the substrate, The conductive pattern is An electrode pad on which an electronic component is mounted; a first teaching pattern having a first line and a second line, the first teaching pattern teaching a mountable range of the electronic component; having When viewed in a direction perpendicular to a mounting surface of the printed circuit board, the electronic component has a first side extending in a first direction that is a direction along the mounting surface, the first line and the second line extend in the first direction; the first side surface is between the first line and the second line in a second direction perpendicular to the first direction and a normal direction of the mounting surface; A printed circuit board, wherein in the first direction, the first line and the second line are each at a different position from the first side.

[0059] As described in the first to third embodiments, the teaching patterns 120a and 120b are formed around the electrode pads 107a and 107b and have a predetermined shape that teaches the mountable range of the electronic component 110 on the electrode pads 107a and 107b. This makes it easy to confirm that the electronic component 110 is correctly mounted in a predetermined position.

[0060] 3(A), 4(A), 5, 6, 7(A), 8(A), 9, and 10(A) to 10(C) show lines 131a, 131b, 132a, 132b and virtual lines 111 and 112. Lines 131a, 131b, 132a, 132b and virtual lines 111 and 112 are examples of at least two lines (first line and second line) that indicate the mountable range of electronic component 110. In this way, at least two lines are useful for visually indicating the mountable range of electronic component.

[0061] When viewed in a direction perpendicular to the mounting surface of the printed circuit board (e.g., -z direction), the electronic component may have a first side extending in a first direction (e.g., x direction or y direction) that is a direction along the mounting surface. Here, the first line and the second line extend in the first direction. There is a second direction (e.g., y direction or x direction) that is perpendicular to the first direction and perpendicular to the normal direction of the mounting surface. In the second direction, the first side may be between the first line and the second line. Furthermore, in the first direction, the first line and the second line may each be located at a different position from the first side. Note that in the second direction, the first line and the second line may each be located at a different position from the first side.

[0062] The lines 131a, 131b and the imaginary line 112 are an example of a first line indicating a first limit position (upper limit position). The lines 132a, 132b and the imaginary line 111 are an example of a second line indicating a second limit position (lower limit position). (Item 2) Item 1 is a printed circuit board according to the present invention; The first line and the second line are on the same side of the electronic component in the first direction.

[0063] As illustrated in FIG. 3(A) and the like, the first line and the second line may be on the same side with respect to the electronic component in the first direction. (Item 3) Item 2. The printed circuit board according to claim 1, the printed circuit board has a first side; The first line is a line parallel to a direction perpendicular to the first side.

[0064] For example, the line 131a and the imaginary line 112a are lines parallel to the x direction and perpendicular to the first side 121a. (Item 4) Item 3. The printed circuit board according to item 3, The second line is a line parallel to a direction perpendicular to the first side.

[0065] For example, the line 132a and the imaginary line 111a are lines parallel to the x direction and perpendicular to the first side 121a. (Item 5) A printed circuit board according to any one of items 1 to 4, The first teaching pattern includes a shape recessed in a direction from a first side of the printed circuit board toward the electrode pad.

[0066] 3A, the teaching pattern 120a includes a shape recessed in a direction from the side 121a toward the electrode pad 107a of the printed circuit board 100. The teaching pattern 120a includes a shape recessed in a direction from the electrode pad 107a of the printed circuit board 100 toward the side 121c. (Item 6) Item 5. The printed circuit board according to item 5, The recessed shape is the first line and the second line; a third line connecting the first line and the second line and parallel to the first side; the first line indicates an upper limit position in a direction parallel to a first side of the printed circuit board within a mountable range of the electronic component, The second line indicates the lower limit position in a direction parallel to the first side of the printed circuit board of the range in which the electronic component can be mounted.

[0067] As illustrated in Fig. 3(A), lines 131a and 132a are an example of a first line and a second line. Line 133a is an example of a third line. Line 131a may indicate the upper limit position of the mountable range of electronic components in a direction parallel to the first side of the printed circuit board. Line 132a may indicate the lower limit position of the mountable range of electronic components in a direction parallel to the first side of the printed circuit board. (Item 7) 5. The printed circuit board according to any one of items 1 to 4, The first teaching pattern includes a shape that protrudes from the electrode pad in a direction toward a first side of the printed circuit board.

[0068] As illustrated in FIG. 7(A) and FIG. 9, the teaching pattern 120a may include a shape that protrudes in the -x direction. (Item 8) Item 7. The printed circuit board according to item 7, The protruding shape is the first line and the second line perpendicular to the first side; a third line connecting the first line and the second line and parallel to the first side; the first line indicates an upper limit position in a direction parallel to a first side of the printed circuit board within a mountable range of the electronic component, The second line indicates the lower limit position in a direction parallel to the first side of the printed circuit board of the range in which the electronic component can be mounted.

[0069] 9, the teaching pattern 120a having a convex shape has a first line 131a, a second line 132a, and a third line 133a. The first line 131a and the second line 132a indicate the limit positions of the range in which the electronic component 110 can be mounted. (Item 9) 5. The printed circuit board according to any one of items 1 to 4, The first teaching pattern includes at least two convex shapes protruding from the electrode pad in a direction toward a first side of the printed circuit board.

[0070] As shown in FIG. 7A, the teaching pattern 120a has two convex shapes that protrude in the -x direction. (Item 10) Item 9. The printed circuit board according to item 9, the at least two convex shapes include a first convex shape and a second convex shape, the first convex shape indicates an upper limit position of a mountable range of the electronic component in a direction parallel to a first side of the printed circuit board, The second convex shape indicates a lower limit position in a range in which the electronic component can be mounted, in a direction parallel to the first side of the printed circuit board.

[0071] As illustrated in Fig. 7(A), the teaching pattern 120a may include a first convex shape 701 and a second convex shape 702. The first convex shape 701 indicates an upper limit position of a range in which an electronic component can be mounted. The second convex shape 702 indicates a lower limit position of a range in which an electronic component can be mounted. As illustrated in Fig. 8(A), the teaching pattern 120b may include a first convex shape 801 and a second convex shape 802. The first convex shape 801 and the second convex shape 802 may also indicate an upper limit position and a lower limit position, respectively.

[0072] 1 and the like, electronic component 110 has four side surfaces 122a to 122d in a plan view. If electronic component 110 is a BGA type, a ball grid is disposed on the bottom surface side of electronic component 110. On the top surface of electronic component 110, the model number of electronic component 110 and the like are printed or engraved. (Item 11) 11. The printed circuit board according to any one of items 1 to 10, the electronic component has a second side, a third side, and a fourth side; the first side surface and the third side surface are parallel to each other; the second side surface and the fourth side surface are parallel to each other; The mountable range of the electronic component is the range that the first side surface and the third side surface can take on the printed circuit board when the printed circuit board is viewed in plan.

[0073] 5, the mountable range of electronic component 110 taught by teaching pattern 120a may be the range that side surface 122b and side surface 122d of electronic component 110 can take. Also, the mountable range of electronic component 110 taught by teaching pattern 120b may be the range that side surface 122a and side surface 122c of electronic component 110 can take. (Item 12) 12. The printed circuit board according to any one of items 1 to 11, The conductive pattern further comprises: a second teaching pattern having a predetermined shape that teaches a mountable range of the electronic component on the electrode pad; the first teaching pattern teaches a mountable range of the electronic component in a direction parallel to a first side of the printed circuit board; The second teaching pattern teaches a mountable range of the electronic component in a direction perpendicular to a first side of the printed circuit board.

[0074] Teaching pattern 120a indicates the range in the y direction where electronic component 110 can be mounted. Teaching pattern 120b indicates the range in the x direction where electronic component 110 can be mounted. This makes it easier to confirm that electronic component 110 is placed at the correct position not only in the y direction but also in the x direction. (Item 13) Item 13. The printed circuit board according to item 12, the first teaching pattern includes a shape protruding from the electrode pad in a direction toward the first side of the printed circuit board, The second teaching pattern includes a shape that protrudes from a second side of the printed circuit board that is perpendicular to the first side toward the electrode pad.

[0075] As shown in Fig. 7A and Fig. 9, the teaching pattern 120a has a shape that protrudes in the -x direction. As shown in Fig. 8A and Fig. 9, the teaching pattern 120b has a shape that protrudes in the -y direction. (Item 14) Item 13. The printed circuit board according to item 12, the first teaching pattern includes a shape recessed in a direction from the first side of the printed circuit board toward the electrode pad, The second teaching pattern includes a shape that protrudes from a second side of the printed circuit board that is perpendicular to the first side toward the electrode pad.

[0076] As shown in Fig. 3A, the teaching pattern 120a has a shape recessed in the x direction. As shown in Fig. 8A and Fig. 9, the teaching pattern 120b has a shape protruding in the -y direction. In this manner, the teaching pattern 120a having a recessed shape and the teaching pattern 120b having a protruding shape may be combined. (Item 15) Item 13. The printed circuit board according to item 12, the first teaching pattern includes a shape recessed in a direction from the first side of the printed circuit board toward the electrode pad, The second teaching pattern includes a shape recessed in a direction from the electrode pad toward a second side of the printed circuit board that is perpendicular to the first side.

[0077] As shown in Fig. 3A, the teaching pattern 120a may have a shape recessed in the +x direction. As shown in Fig. 4A, the teaching pattern 120b may have a shape recessed in the +y direction. (Item 16) Item 13. The printed circuit board according to item 12, the first teaching pattern includes a shape protruding from the electrode pad in a direction toward the first side of the printed circuit board, The second teaching pattern includes a shape recessed in a direction from the electrode pad toward a second side of the printed circuit board that is perpendicular to the first side.

[0078] As illustrated in Fig. 7(A) and Fig. 9, the teaching pattern 120a may have a shape that protrudes in the -x direction. As illustrated in Fig. 4(A), the teaching pattern 120b may have a shape that is recessed in the +y direction. In this manner, the teaching pattern 120a having a convex shape and the teaching pattern 120b having a concave shape may be combined. (Item 17) 12. The printed circuit board according to any one of items 1 to 11, the electronic component has a second side, a third side, and a fourth side; the first side surface and the third side surface are parallel to each other; the second side surface and the fourth side surface are parallel to each other; The conductive pattern further includes a second teaching pattern, the first teaching pattern indicates a mountable range of the electronic component on the first side surface, The second teaching pattern indicates a mountable range of the electronic component with respect to the third side surface.

[0079] 6, teaching pattern 601 indicates a mountable range of electronic component 110 for side surface 122b. Teaching pattern 602 indicates a mountable range of electronic component 110 for side surface 122d. Teaching pattern 603 indicates a mountable range of electronic component 110 for side surface 122a. Teaching pattern 604 indicates a mountable range of electronic component 110 for side surface 122c. In this manner, multiple teaching patterns 120 indicating alignment of electronic component 110 in the y direction may be provided. Similarly, multiple teaching patterns 120 indicating alignment of electronic component 110 in the x direction may be provided. (Item 18) 12. The printed circuit board according to any one of items 1 to 11, the electronic component has a second side, a third side, and a fourth side; the first side surface and the third side surface are parallel to each other; the second side surface and the fourth side surface are parallel to each other; The conductive pattern further includes a second teaching pattern, the first teaching pattern indicates a mountable range of the electronic component on the first side surface, The second teaching pattern indicates a mountable range of the electronic component on the second side.

[0080] As shown in Fig. 3(A) and other figures, teaching pattern 120a indicates a mountable range of side surface 122b for electronic component 110. As shown in Fig. 4(A) and other figures, teaching pattern 120b indicates a mountable range of side surface 122a for electronic component 110. (Item 19) A printed circuit board is provided. The printed circuit board is A substrate; A conductive pattern provided on the substrate, The conductive pattern is An electrode pad on which an electronic component is mounted; a first teaching pattern having a first line and a second line, the first teaching pattern teaching a mountable range of the electronic component; having When viewed in a direction perpendicular to a mounting surface of the printed circuit board, the electronic component has a first side extending in a first direction that is a direction along the mounting surface, the first line and the second line extend in the first direction; the first side surface is between the first line and the second line in a second direction perpendicular to the first direction and a normal direction of the mounting surface; In the first direction, the first line and the second line are at different positions from the first side surface, The electronic component is an optical sensor including a chip-type light-emitting element or a chip-type light-receiving element.

[0081] 11, the electronic component 110 may be an LED 1101 or a PD 1102. This will allow the mounting position of the LED 1101 or the PD 1102 to be accurate, and will suppress a decrease in the amount of light received by the optical sensor 1100. (Item 20) A conveying means for conveying the sheet along a conveying path; a detection unit that detects a passing timing of the sheet conveyed by the conveying unit or detects a type of the sheet; an image forming unit for forming an image on the sheet, The detection means has a printed circuit board, The printed circuit board is A substrate; A conductive pattern provided on the substrate, The conductive pattern is An electrode pad on which an electronic component is mounted; a first teaching pattern having a first line and a second line, the first teaching pattern teaching a mountable range of the electronic component; having When viewed in a direction perpendicular to a mounting surface of the printed circuit board, the electronic component has a first side extending in a first direction that is a direction along the mounting surface, the first line and the second line extend in the first direction; the first side surface is between the first line and the second line in a second direction perpendicular to the first direction and a normal direction of the mounting surface; In the first direction, the first line and the second line are at different positions from the first side surface, The electronic component includes a chip-type light-emitting element or a chip-type light-receiving element.

[0082] The transport roller 13 is an example of a transport rotating body. The photosensitive drum 18 and the transfer unit 19 are examples of an image forming unit. By employing the optical sensor 1100 as the sheet sensor 16, the image forming device 1200 can be controlled with high precision. For example, the position at which the toner image is formed on the sheet 8 will be more accurate. Also, the fixing temperature of the fixing device 17, which is adjusted according to the surface properties or type of the sheet 8, will be more accurately controlled. As a result, the density and gradation characteristics of the toner image formed on the sheet 8 will be improved.

[0083] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0084] 100: printed circuit board, 102: substrate, 104: conductive pattern, 107a, 107b: electrode pads

Claims

1. A substrate; A conductive pattern provided on the substrate, The conductive pattern is An electrode pad on which an electronic component is mounted; a first teaching pattern having a first line and a second line, the first teaching pattern teaching a mountable range of the electronic component; A printed circuit board having When viewed in a direction perpendicular to a mounting surface of the printed circuit board, the electronic component has a first side extending in a first direction that is a direction along the mounting surface, the first line and the second line extend in the first direction; In a second direction perpendicular to the first direction and the mounting surface, the first side surface is between the first line and the second line; A printed circuit board, wherein in the first direction, the first line and the second line are each at a different position from the first side.

2. The printed circuit board according to claim 1 , wherein the first line and the second line are on the same side relative to the electronic component in the first direction.

3. the printed circuit board has a first side; The printed circuit board according to claim 2 , wherein the first line is parallel to a direction perpendicular to the first side.

4. The printed circuit board according to claim 3 , wherein the second line is parallel to a direction perpendicular to the first side.

5. The printed circuit board according to claim 1 , wherein the first teaching pattern includes a shape recessed in a direction from a first side of the printed circuit board toward the electrode pad.

6. The recessed shape is the first line and the second line; a third line connecting the first line and the second line and parallel to the first side; the first line indicates an upper limit position in a direction parallel to a first side of the printed circuit board within a mountable range of the electronic component, the second line indicates a lower limit position in a range in which the electronic component can be mounted, in a direction parallel to the first side of the printed circuit board; The printed circuit board according to claim 5.

7. The printed circuit board according to claim 1 , wherein the first teaching pattern includes a shape protruding from the electrode pad in a direction toward a first side of the printed circuit board.

8. The protruding shape is the first line and the second line perpendicular to the first side; a third line connecting the first line and the second line and parallel to the first side; the first line indicates an upper limit position in a direction parallel to a first side of the printed circuit board within a mountable range of the electronic component, the second line indicates a lower limit position in a range in which the electronic component can be mounted, in a direction parallel to the first side of the printed circuit board; The printed circuit board according to claim 7.

9. The printed circuit board according to claim 1 , wherein the first teaching pattern includes at least two convex shapes protruding from the electrode pad in a direction toward a first side of the printed circuit board.

10. the at least two convex shapes include a first convex shape and a second convex shape, the first convex shape indicates an upper limit position of a mountable range of the electronic component in a direction parallel to a first side of the printed circuit board, the second convex shape indicates a lower limit position in a range in which the electronic component can be mounted, in a direction parallel to the first side of the printed circuit board; The printed circuit board according to claim 9.

11. the electronic component has a second side, a third side, and a fourth side; the first side surface and the third side surface are parallel to each other; the second side surface and the fourth side surface are parallel to each other; the mountable range of the electronic component is a range that the first side surface and the third side surface can take on the printed circuit board when the printed circuit board is viewed in a plan view; The printed circuit board according to claim 1 .

12. The conductive pattern further comprises: a second teaching pattern having a predetermined shape that teaches a mountable range of the electronic component on the electrode pad; the first teaching pattern teaches a mountable range of the electronic component in a direction parallel to a first side of the printed circuit board; the second teaching pattern teaching a mountable range of the electronic component in a direction perpendicular to a first side of the printed circuit board; The printed circuit board according to claim 1 .

13. the first teaching pattern includes a shape protruding from the electrode pad in a direction toward the first side of the printed circuit board, the second teaching pattern includes a shape protruding from a second side of the printed circuit board perpendicular to the first side toward the electrode pad; The printed circuit board according to claim 12.

14. the first teaching pattern includes a shape recessed in a direction from the first side of the printed circuit board toward the electrode pad, the second teaching pattern includes a shape protruding from a second side of the printed circuit board perpendicular to the first side toward the electrode pad; The printed circuit board according to claim 12.

15. the first teaching pattern includes a shape recessed in a direction from the first side of the printed circuit board toward the electrode pad, the second teaching pattern includes a shape recessed in a direction from the electrode pad toward a second side of the printed circuit board perpendicular to the first side, The printed circuit board according to claim 12.

16. the first teaching pattern includes a shape protruding from the electrode pad in a direction toward the first side of the printed circuit board, the second teaching pattern includes a shape recessed in a direction from the electrode pad toward a second side of the printed circuit board perpendicular to the first side, The printed circuit board according to claim 12.

17. the electronic component has a second side, a third side, and a fourth side; the first side surface and the third side surface are parallel to each other; the second side surface and the fourth side surface are parallel to each other; The conductive pattern further includes a second teaching pattern, the first teaching pattern indicates a mountable range of the electronic component on the first side surface, The second teaching pattern indicates a mountable range of the electronic component with respect to the third side surface. The printed circuit board according to claim 1 .

18. the electronic component has a second side, a third side, and a fourth side; the first side surface and the third side surface are parallel to each other; the second side surface and the fourth side surface are parallel to each other; The conductive pattern further includes a second teaching pattern, the first teaching pattern indicates a mountable range of the electronic component on the first side surface, the second teaching pattern indicates a mountable range of the electronic component on the second side surface; The printed circuit board according to claim 1 .

19. A printed circuit board according to any one of claims 1 to 18, The electronic component is an optical sensor including a chip-type light-emitting element or a chip-type light-receiving element.

20. A conveying means for conveying the sheet along a conveying path; an optical sensor that detects the passing timing of the sheet conveyed by the conveying means or detects the type of the sheet; and an image forming means for forming an image on the sheet, The optical sensor comprises a printed circuit board according to claim 19, The electronic component includes a chip-type light-emitting element or a chip-type light-receiving element.

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